V • ) APRIL 1981 Vol. 6,: No. 4 $2.50 in USA/$2.95 in Canada A McGraw-Hill Publication the small systems journal FUTURE COMPUTERS I masm YOUR CHOICE-smart either way • Over 140 software driven functions • 82 x 24 or 82 x 20 screen format — software selectable • High resolution 7x12 matrix characters - P-31 green phosphor • Upper/lower case character set — plus graphics character set • 56-key alphanumeric keyboard — plus 12-key cursor, numeric pad • Internal editing functions - insert, delete, scroll, roll, slide, etc. • Parallel printer I/O port • 50 to 38,400 baud operation — programmable • Cursor type, cursor position, print control characters, protected fields, shift inversion, dual intensity and many other features 8212 — twelve-inch diagnonal screen or 8209 — nine-inch diagnonal screen SOUTHWEST TECHNICAL PRODUCTS CORPORATION 219 W. RHAPSODY SAN ANTONIO, TEXAS 78216 (512) 344-0241 Circle 360 on inquiry card. INTELLIGENT 110 I/O INTERFACES COLOR GRAPHICS MULTI-PROCESSING IT-MBYTE EXTENSIVE COLOR FLOPPV DISK HARD DISK JOYSTICK SOFTWARE PRINTERS MONITORS DRIVES DRIVE CONSOLE SUPPORT What Cromemco computer card capability can do for you The above diagram shows in a func- tional way one of the most complete lines of computer cards in the industry. Look it over carefully. It could be well worth your while. These are all cards that plug into our S-100 bus microcomputers. You can also assemble them into a custom system in convenient Cromemco card cages. MULTI-PROCESSING AND INTELLIGENT I/O The range of capabilities and versatility you can draw upon is enormous. In processors, for example, you have a choice of CPU's including our extremely useful new I/O Processor. This can be used as a satellite processor to do off-line processing, multi-processing, and to form intelligent I/O. It opens the door to a whole new group of applications and tasks. Ask us about it. HIGH RESOLUTION COLOR GRAPHICS Again, you can have beautiful high- resolution color graphics with our color graphics interface. You can select from over 4000 colors and have a picture with a resolution at least equal to quality broadcast-TV pictures. Q You have an unprecedented selection of memory including our unusual 48K and 16K two-port RAMs which allow high-speed color graphics. LOTS OF STORAGE These days you often want lots of disk storage. So you can select from our disk controller card which will operate our 5" and 8" floppy disk drives (up to 1.2 megabytes). Or select our WDI interface to operate our 11-megabyte hard disk drives. POWERFUL SOFTWARE AND PERIPHERAL SUPPORT There's much more yet you can do with our cards. And, of course, there's an easy way to put them to work in our 8-, 12-, and 21 -slot card cages. Our PS8 power supply makes it simple to get the system into operation. Finally, Cromemco offers you the strongest software support in the industry Cromemco ™ incorporated 280 BERNARDO AVE., MOUNTAIN VIEW, CA 94040 • (415)964-7400 Tomorrow's computers today Circle 1 on Inquiry card. with languages like FORTRAN, C, COBOL, ASSEMBLER, LISP, BASIC and others. There is also a wide choice from independent vendors. To top it all off, you can draw from a substantial array of peripherals: ter- minals, printers, color monitors and disk drives. CONTACT YOUR CROMEMCO REP There is even more capability than we're able to describe here. Contact your Cromemco rep now and get this capability working for you. CROMEMCO COMPUTER CARDS PROCESSORS — 4 MHz Z-80 A CPU, single card computer, I/O processor • MEMORY — up to 64K including special 48K and 16K two- port RAMS and our very well known BYTESAVERS® with PROM programming capability • HIGH RESOLUTION COLOR GRAPHICS - our SDI offers up to 754 x 482 pixel resolution. • GENERAL PURPOSE INTERFACES— QUADART four-channel serial communications, TU-ART two-channel parallel and two-channel serial, 8PIO 8-port parallel, 4PIO 4-port isolated parallel, D+ 7A 7-channel D/A and A/D converter, printer inter- face, floppy disk controller with RS-232 inter- face and system, diagnostics, wire-wrap and extender cards for your development work. Management Information Display Ultrasonic heart sector scan High-resolution display with alphanumerics Get the professional color display that has BASIC/FORTRAN simplicity LOW-PRICED, TOO Here's a color display that has everything: professional-level resolution, enormous color range, easy software, NTSC conformance, and low price. Basically, this new Cromemco Model SDI* is a two-board interface that plugs into any Cromemco computer. The SDI then maps computer display memory content onto a convenient color monitor to give high-quality, high- resolution displays (756 H x 482 V pixels). When we say the SDI results in a high- quality professional display, we mean you can't get higher resolution than this system offers in an NTSC-conforming display. The resolution surpasses that of a color TV picture. BASIC/FORTRAN programming Besides its high resolution and low price, the new SDI lets you control with optional Cromemco software packages that use simple BASIC- and FORTRAN- like commands. Pick any of 16 colors (from a 4096-color palette) with instructions like DEFCLR (c, R, G, B). Or obtain a circle of specified size, location, and color with XCIRC (x, y, r, c). t aW\ •U.S. Pat. No. 4121283 Model SDI High-Resolution Color Graphics Interface HIGH RESOLUTION The SDI's high resolution gives a professional-quality display that strictly meets NTSC requirements. You get 756 pixels on every visible line of the NTSC standard display of 482 image lines. Ver- tical line spacing is 1 pixel. To achieve the high-quality display, a separate output signal is produced for each of the three component colors (red, green, blue). This yields a sharper image than is possible using an NTSC-composite video signal and color TV set. Full image quality is readily realized with our high- quality RGB Monitor or any conventional red/green/blue monitor common in TV work. Model SDI plugs into Z-2H 11 -mega byte hard disk computer or any Cromemco computer DISPLAY MEMORY Along with the SDI we also offer an optional fast and novel two-port memory that gives independent high-speed access to the computer memory. The two-port memory stores one full display, permit- ting fast computer operation even during display. CONTACT YOUR REP NOW The Model SDI has been used in scien- tific work, engineering, business, TV, color graphics, and other areas. It's a good example of how Cromemco keeps computers in the field up to date, since it turns any Cromemco computer into an up-to-date color display computer. The SDI has still more features that you should be informed about. So contact your Cromemco representative now and see all that the SDI will do for you. a Cromemco incorporated 280 BERNARDO AVE., MOUNTAIN VIEW, CA 94043 • (415) 964-7400 Tomorrow's computers today Circle 1 on inquiry card. In The Queue Volume 6, Number 4 April 1 98 1 Features ZO Recurrence in Numerical Analysis by James J Davidson / Recurrence can be used to simplify the calculation of Bessel functions. 36 Build a Low-Cost Logic Analyzer by Steve Ciarcia I Turn your computer into a powerful diagnostic tool. 64 A-L BYTE Guide to The National Com- puter Conference and Chicago / Up-to-date infor- mation on the conference, the city, and much more. 66 Digital Minicassette Controller by James Kahn / Use an intelligent peripheral controller to lighten the load on your computer system. 102 Programming the Game of Go by Jonathan K Millen / Even though Go is much harder than chess, a microcomputer Go program can produce surprisingly good play. 122 Build Your Own Turing Machine by James Willis / Three different practical versions of this theoretical tool produce the same output. 1 50 A Closer Look at the Tl Speak & Spell by Peter Vernon / The author expands on Michael Rigsby's September 1980 BYTE article. 2 1 8 An Introduction to Data Compres- sion by Harold Corbin / Information can be transmitted and stored using fewer data bits by ap- propriate techniques. Build an Intercomputer Data Link by Mike Wingfield / Using this software, systems based on the 6800 microprocessor can communicate with other systems. 290 Three-Dimenslonal Computer Graphics, Part 2 by Franklin C Crow / Soft- ware to display solid objects without hidden lines and surfaces. 348 PADDLES: Interfacing with Modular Breadboards by Roger J Combs and Paul Field / Designing and implementing breadboard cir- cuits is greatly eased with the use of these standard- ized modules. Reviews 46 The MicroAce Computer by Delmar Searls 94 A Reformatter for CP/M and IBM Floppy Disks by John Lehman 1 88 Three Versions of APL by Gregg Williams Nucleus 6 10, 12 32, 98, 148 158 186 212 328 332 338 344 345 359 414 415 416 Editorial: Future Trends in Personal Computing 302 BYTE's Bugs Letters 34 Programming Quickies: Apple Name-Address; A Graphic Execution Display 304, 310, 314 Technical Forum: MicroShakespeare Revisited or Kilobard; An ADM-3 Emulator for the Hazeltine 1 500; Challenger Writes on Comprint; On the Use of Fourier Transforms to Explore Biological Rhythms System Notes: A Relocatable Bootstrap for t+ie Tarbell Disk Controller Clubs and Newsletters Cartoon BYTELINES Ask BYTE Event Queue Books Received Software Received BYTE's Bits What's New? Unclassified Ads BOMB, BOMB Results Reader Service EITE Page 36 Page 46 Page 186 Page 302 April 1981 © BYTE Publications Inc 3 m Editor in Chief Christopher Morgan Managing Editor Mark Haas Technical Editors Gregg Williams. Senior Editor; Richard S Shuford; Curtis P Feigel; Harold Nelson; Stan Miastkowski; Kevin Cohan; Bruce Roberts; Charles Freiberg. New Products Editor; Steve Garcia. Mark Dahmke, Consulting Editors; Jon Swanson, Draftsman Copy Editors Richard Friedman, Chief; Faith Hanson; Warren Williamson; Anthony J Lockwood; Ann Graves Assistants Faith Ferry; Debe Wheeler; Karen A Cilley Production Nancy Estle, Director; Christine Dixon, Asst Director; Wai Chiu Li; Jonathan M Graves; Deborah Porter; Sherry McCarthy. Chief Typographer; Debi Fredericks; Donna Sweeney; Valerie Horn Advertising Thomas Harvey, Director; Marion Gagnon; Barbara J Greene; Rob Hannings Circulation Gregory Spitzfaden, Manager; Andrew Jackson, Asst Manager; Agnes E Perry; Barbara Varnum; Louise Menegus; Bill Watson; Dealer Sales: Melanie Bertoni Marketing Jill E Callihan, Special Projects; Laura Hanson Controller's Office Daniel Rodrigues, Controller; Mary E Fluhr, Asst Controller; Karen Burgess; Jeanne Cilley Traffic N Scott Gagnon; Robert A Fiske Receptionist Jacqueline Earnshaw Publishers Virginia Londoner; Gordon R Williamson; John E Hayes, Associate Publisher; Cheryl A Hurd, Publisher's Assistant Officers of McGraw-Hill Publications Com- pany: Paul F McPherson, President; Executive Vice Presidents: James E Boddorf, Gene W Simpson; Group Vice President: Daniel A McMillan; Senior Vice President-Editorial: Ralph R Schulz; Vice Presidents: Kemp Anderson, Business Systems Development; Robert B Doll, Circulation; James E Hackett, Controller; Eric B Herr, Planning and Development; H John Sweger, Marketing. Officers of the Corporation: Harold W McGraw Jr. President, Chief Executive Officer and Chairman of the Board; Robert F Landes, Senior Vice President and Secretary; Ralph J Webb, Treasurer. In This Issue "Future Computers" is our cover theme this month and the subject of the editorial. Before you write to comment on our cover's "unusual" design approach (created by artist Robert Tinney), keep in mind the proximity of April 1. Elsewhere in this issue we describe Steve Ciarcia's latest project, a low-cost logic analyzer, and tell how to build your own Turing machine. Other articles include: a follow-up to our earlier review of the Sinclair computer, this time a description of the MicroAce kit version; a reformatter for CP/M and IBM- format floppy disks; a closer look at the Tl Speak & Spell; a fascinating review of three different APL packages for the patient (but eager) APL fans in our audience; details about data compression; all about intercomputer data links and the game of Go; and the conclusion of an article from last month about 3-D computer graphics. BYTE is published monthly by BYTE Publications Inc. 70 Main St, Peterborough NH 03458, phone |603) 924-928 1 , a wholly-owned subsidiary of McGraw-Hill. Inc. Address subscriptions, change of address. USPS Form 3579, and fulfillment questions to BYTE Subscriptions. POB 590, Martinsville NJ 08836. Controlled circulation postage paid at Waseca, Minnesota 56093 - USPS Publication No. 528890 (ISSN 0360-5280). Canadian second class registration number 9321 . Subscriptions are S 19 for one year, S34 for two years, and S49 for three years in the USA and its possessions. In Canada and Mexico, S21 for one year, S38 for two years. S55 for three years. S43 for one year air delivery to Europe.- S35 surface delivery elsewhere. Air delivery to selected areas at additional rates upon request. Single copy price is S2.50 in the USA and its possessions, S2.95 in Canada and Mexico, S4.00 in Europe, and S4.50 elsewhere. Foreign subscriptions and sales should be remitted in United States funds drawn on a US bank. Printed in United States of America. Address all editorial correspondence to the editor at BYTE, POB 372, Hancock NH 03449. Unacceptable manuscripts will be returned if accompanied by sufficient first class postage. Not responsible for lost manuscripts or photos. Opinions expressed by the authors are not necessarily those of BYTE. Entire contents copyright © 1981 by BYTE Publications Inc. All rights reserved. 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Subscription WATS Line: (800) 258-5485 Office hours: Mon-Thur 8:30 AM - 4:30 PM, Friday 8:30 AM - Noon, Eastern Time NATIONAL ADVERTISING SALES REPRESENTATIVES: NORTHEAST (617) 444-3946 Hajar Associates 280 Hillside Ave Needham Heights MA 02 1 94 NORTHWEST (415J 964-0706 Hajar Associates lOOOEIwellCt, Suite 227 Palo Alto CA 94303 MIDWEST (312) 966-0160 Hajar Associates 5225 Old Orchard Dr Skokie IL 60076 SOUTHWEST (714) 540-3554 Hajar Associates 3303 Harbor Blvd Suite K-4 Costa Mesa CA 92626 MID ATLANTIC (212) 682-5844 Hajar Associates 52 1 Fifth Ave New York NY 10017 SOUTHEAST (305) 886-7210 Hajar Associates 1220 Prairie Lane Apopka FL 32703 April 1981 © BYTE Publications Inc "... stands well above other S-100 graphics dis- plays in its price and per- formance range." BYTE, Product Review . better monochromatic . display . ELECTRONIC DESIGN, 1981 Technology Forcast MICROANGELO HIGH RESOLUTION GRAPHICS SINGLE BOARD COMPUTER 512 x 480 resolution black and white and vivid color displays RS-170 com- posite or direct drive output Local or external sync generation 4MhzZ80 microprocessor 60 hertz real- time clock 8 level interrupt tie-in IEEE S100 bus compatible Screenware™ Pak I A 4K byte operating system resident in PROM on MicroAngelo™. Pak I emulates an 85 character by 40 line graphics terminal and provides over 40 graphics commands. Provisions exist for user defined character sets and directly callable user extensions to Screenware™ Pak I. Screenware™ Pak II An optional software superset of Pak I which adds circle generation, polygon flood, program- mable split screen for separate graphics and ter- minal I/O, relative coordinates, faster vector and character plotting, a macro facility, full UCSD Pascal compatibility, and more. Light pen interface Time multi- plexed refresh 4K resident Screenware™ Pak I operating system 32KRAM isolated from host address space High speed communications over parallel bus ports And now. . .COLOR" The new MicroAngelo™ Palette board treats from 2 to 8 MicroAngelos as "bit planes" at a full 512 x 480 resolution. Up to 256 colors may be chosen from 16.8 million through the program- mable color lookup table. Overlays, bit plane precedence, fade-in, fade-out, gray levels, blink- ing bit plane, and a highly visual color editor are standard. Circle 2 on inquiry card. SOON 8455-D Tyco Road • Vienna, Virginia 22180 • TWX: 710-831-9087 • (703) 827-0888 Circle 3 on inquiry card. UCSD PASCAL FORTRAN Portable Develop on a Z-flOt, runonLSI-1lt, T.I. 990, 6800 or vice versa Efficient Structured, readable Speeds development X5 Easy maintenance Powerful Full standard Pascal plus extensions ANSI '77 Fortran Subset Cost Effective Complete system Including Interpreter, screen editor, utilities, filer, assembler, and compiler, with Pascal $400 with Fortran $450 with Both $600 APPLICATIONS PFAS (Pascal File Access System) Keyed-ISAM in 6K user memory $200 INTELLECT UL VI.2 A full range LISP interpreter for UCSD p-systems $200 MEDOFFICE Professional medical office software for 1 to 5 doctors. Call for pricing. DATEBOOK Appointment scheduling on your micro $295 READY TO RUN ON DEC PDP-11 for TRS-80 MODEL 11 § PCD SYSTEMS P. 0. Box 143 Penn Yan, NY 14527 315-536-3734 *TM Univ. of Calif. JTMofZllog JTM of Digital Equipment STM of Tandy Corp. Editorial Future Trends in Personal Computing Chris Morgan, Editor in Chief Future Com- puters — what will they be like? Some exciting developments have been occurring in the industry lately that should give us some clues. I at- tended the Con- sumer Electronics Show in Las Vegas this past January, where Toshiba in- troduced what could be the most significant product of the year for the personal-comput- ing market: a pock- et-size flat-screen television set. While no specific mention was made of its possible use with a personal computer, it takes only a moment's thought to see the potential of this engineering marvel. First introduced in japan some months ago, the Toshiba television has a 4.1 by 3.1 cm (l 3 / 5 by 1% inch) LCD (liquid-crystal display) screen housed in a case measuring 17.3 by 8.2 by 1.8 cm (6% by 3% by 7 /io inches)! It has only half the resolu- tion of a standard CRT (cathode-ray tube) display, but its small size masks that fact effectively. Toshiba has also solved the problem of liquid-crystal "overhang," the slow-fade effect that plagues LCDs in electronic games. The response time of this particular design is fast enough to handle the 1/30 of a second television-frame refresh rate. Although the screen is dimmer than a CRT display (the im- Photo 1: Toshiba's new pocket-size television prototype. A built-in zoom feature is available that enlarges any one of the four screen quadrants for close-up viewing. Photo by Stan Miastkowski. age is formed from reflected rather than transmitted light), it has accept- able contrast and sharpness. The screen is fed by a bank of shift regis- ters; it would be an easy task to display computer graphics and characters on it. The Toshiba flat- screen unit is still in the prototype phase and will probably not be available for a year or so, retailing for approximately $600. I predict that with- in two years the market will be flooded with porta- ble computers hav- ing built-in screens of every size and shape. Sony has introduced a new elec- tronic "typewriter" that fits in a brief- case and lets you enter, store, and edit up to 200 pages of text using a built-in microcassette recorder. Text is displayed on a one-line liquid- crystal display. Combine such a de- vice with a flat-screen multiline video display and you have a very attrac- tive concept, indeed. Another Sony breakthrough is a new miniature floppy-disk system (see photo 3, page 10). Each disk measures 8.9 cm (3Vi inches) in diameter and holds over 800,000 bytes 1 The disk resides in a rigid housing for protection. Sony plans to introduce the disk as part of a new, miniature word-processing system. Percom Mini-Disk Drive Systems for TRS-80* Computers . . . Now! Add-On and Add-In Mini-Disk Storage for your Model III. New for the TRS-80* Model III Patterned after our fast-selling TFD Model I drives. And subjected to the same reliability controls. These new TFD mini-disk systems for the Model III provide more features than Tandy drives, yet cost far less. • Flippy Capability: Both internal (add-in) and external (add-on) drives permit recording on either side of a diskette. • Greater Storage Capacity: Available with either 40- or 80-track drive mechanisms, Percom TFD mini-disk systems store more. A 40-track drive stores up to 180 Kbytes — formatted — on one side of a 5-inch diskette. An 80-track drive stores a whopping 364 Kbytes. • 1.5 Mbyte On-line: The Percom drive controller (included with the initial drive) handles up to four drives. With four 80-track mini-disk drives you can access over 1.5 million bytes of on-line file data. Moreover, the initial drive may be either an internal add-in drive or an external add-on drive. And whichever configuration you get, the initial drive kit comes complete with our advanced 4-drive controller, interconnecting cables, power supplies, installation hardware, a DOS and of course the drive mechanism itself. • First Drive Includes DOS: OS-80™, Percom's fast extendable BASIC-language disk operating system, is included on diskette when you purchase an initial drive kit. Originally called MicroDOS, OS-80 was favorably reviewed in the June 1980 issue of Creative Computing magazine. • Works with Model III TRSDOS: Besides being fully hardware compatible, Percom's Model III 40-track drive systems may be operated with Tandy's Model III TRSDOS — without any modifications whatsoever. And, TRSDOS may be easily upgraded with simple software patches for operating 80-track drives. Percom TFD add-on drives start at only $399. Model III Drive kits start at only $749.95. Quality Percom products are available at authorized dealers. Call toll free 1-800-527-1592 for the address of your nearest dealer or to order direct from Percom. The industry leader in microcomputer peripherals, Percom not only gives you better design, better quality and first-rate service, but you pay less to boot. Still #1 for Model I As if greater storage capacities, exceptional quality control measures and lower prices aren't reasons enough to make Percom your first choice for Model I add-on drives, all Percom Model I drives are also rated for double-density operation. Add our innovative DOUBLER™ adapter to your Model I Expansion Interface, and with Percom drive systems you can enjoy the same double-density storage capability as Model III owners. The DOUBLER includes a TRSDOS*-like double-density disk operating system called DBLDOS™ We also offer a double-density Model I version of OS-80 as well as DOUBLEZAP programs for modifying NEWDOS/80 and VTOS 4.0t for DOUBLER compatibility. Of course you don't have to upgrade your computer for double-density operation to use Percom mini-disk drive systems. In single-density operation, our TRS-80* Model I compatible 40-track drives store 102 Kbytes of formatted data on one side of a diskette, and our 80-track drives store 205 Kbytes. By comparison, Tandy's standard drive for the Model I stores just 86 Kbytes. And like our Model III drives, Model I add-on drives are optionally available with "flippy" storage capability. System Requirements: Model III: 16-Kbyte system (min) and Model III BASIC. The second internal drive may be installed after the first internal drive kit is installed, and external drives #2, #3 and #4 may be added if either an internal or external first-drive kit has been installed. External drives #3 and #4 require an optional interconnecting cable. Model I: 16-Kbyte system (min), Level II BASIC, Expansion Interface, disk operating system and an interconnecting cable. For double-density storage, a Percom DOUBLER must be installed in the Expansion Interface and DBLDOS (comes with the DOUBLER) or other double-density DOS must be used. For single-density operation, a Percom SEPARATOR™ adapter, installed in the Expansion Interface, will virtually eliminate "CRC ERROR — TRACK LOCKED OUT' read eiTOrS. Prices and specifications subject to change without notice. PEfiGOM PERCOM DATA COMPANY, INC. 211 N. KIRBY GARLAND. TEXAS 75042 C214) 272-3421 •Trademark of Tandy Radio Shack Corporation which has no relationship to Percom Data Company. ™DOUBLER, DBLDOS. OS-80 and SEPARATOR are trademarks of Percom Data Company. Inc. tTrademark of Virtual Technology Corporation. Circle 4 on inquiry card. BYTE April 1981 Editorial Photo 2: The Osborne I per- sonal computer. This new 64 K, Z80A machine has two floppy-disk drives and fits under an airline seat. Price: $1795. Photo by Elliot Varner Smith. Although no official word has come from the company, we have learned that it is developing a complete personal- computer system. Fujitsu and Seiko are also developing personal computers for the U.S. market. New Trends in Portability: The Osborne I This month Adam Osborne introduced a new personal computer, called the Osborne I, at the West Coast Com- puter Faire in San Francisco. Its features include: a Z80A processor; 64 K bytes of dynamic programmable mem- ory (60 K bytes are available to the programmer; the re- maining 4 K bytes are used by the display screen); IEEE and RS-232C interfaces; modem electronics; a 5-inch video monitor with 24 rows of 50 characters, upper- and lowercase, two display intensities, and underlining for all characters; two 5-inch single-density, single-sided floppy- disk drives; standard typewriter keyboard; 10-key nu- meric pad; two pockets for storing floppy disks; and the following software: the CP/M operating system, CBASIC, WordStar, Mailmerge, and a CP/M-compati- ble spread sheet program that resembles VisiCalc. There are two particularly interesting points about this computer: (1) it will cost $1795, and (2) it's portable! An optional battery pack will be sold with the unit. Also op- tional are a 9-inch monitor, an acoustic coupler, and double-density, double-sided floppy-disk drives. The $1795 price tag (which includes all the software) is re- markably low. It remains to be seen if the company can turn a profit at this price. I recently had an opportunity to see the Osborne I in action. I was impressed with its compactness: it will fit under an airplane seat. (Adam PASCAL/Z ™- Q.E.D. Ithaca Intersystems PASCAL/Z is the most powerful CP/M™ compatible Z-80™ Pascal compiler ever . . . and here's why: PASCAL/Z generates true Z-80 native code - ROMable and re-entrant — 5-1 OX faster than P-code interpreters; permits separate compilation; supports Direct File Access and variable length STRINGs; utilizes fast one-pass recursive descent organization; the macro-assembler generates relocatable object modules; and much, much more. Complete package includes compiler, macro-assembler, linker/loader and source for the full library on one disk; with free copy of Jensen/Wirth book and complete documenta- tion. Only $395.00. IT'S DEMONSTRABLE! Don't just take our word for it. Ask for a demonstration of these features and more today at Computerland® and other full-service computer stores. Ithaca Intersystems Inc., 16S0 Hanshaw Road P.O. Box 91, Ithaca, N.Y. 14850. Phone (607) 257-0190 Computerland is a registered trademark of Computerland Corporation. CP/M and Z-80 are trademarks of Digital Research Corp. and Zilog, Inc. respectively. PASCAL/Z and InterSystems are trademarks of Ithaca Intersystems Inc. 8 April 1981 © BYTE Publications Inc Circle 5 on inquiry card. Intersysten Micros for bigger ideas. The Intersystems price-performance-reliability story now has three versions. While everyone's been busy trying to convince you that large buses housed in strong metal boxes will guarantee versatility and ward off obsolescence, we've been busy with something better. Solving the real problem with the first line of computer products built from the ground up to con- form to the new IEEE S-100 Bus Standard. Offering you extra ver- satility in 8-bit applications today. And a full 16 bits tomorrow. We call our new line Series II. And even if you don't need the full 24-bit address for up to 16 megabytes (!) of memory right now, they're something to think about. Because of all the perform- ance, flexibility and economy they offer. Whether you're looking at one of our three mainframes, at a new mainframe, expanding your present one or upgrading your system with an eye to the future. (Series II boards are compatible with most existing S-100 systems and all IEEE S-100 Standard cards as other manufacturers get around to building them.) Consider some of the fea- tures: Reliable operation to 4MHz and beyond. Full compatibility with 8- and 16-bit CPUs, pe- ripherals and other devices. Eight levels of prioritized interrupts. Up to 16 individually-addressable DMA devices, with IEEE Standard overlapped operation. User-selec- table functions addressed by DIP- switch or jumpers, eliminating sol- dering. And that's just for openers. The best part is that all this heady stuff is available nowl In our advanced processor — a full IEEE Bus Master featuring Memory Map addressing to a full mega- byte. Our fast, flexible 16K Static RAM and 64K Dynamic RAM boards. An incredibly versatile and Circle 6 on inquiry card. economical 2-serial, 4-parallel Multiple I/O board. Our 6-serial I/O board. Our Double-Density High-Speed Disk Controller. And what is undoubtedly the most flex- ible front panel in the business. Everything you need for a com- plete IEEE S-100 system. Available separately, or all together in your choice of DPS-1 mainframe styles. Whatever your needs, why dump your money into obsolete products labelled "IEEE timing compatible" or other words peo- ple use to make up for a lack of product. See the future now, at your Intersystems dealer or call/ write for our new catalog. We'll tell you all about Series II and the new IEEE S-100 Bus we helped pioneer. Because it doesn't make sense to buy yesterday's products when tomorrow's are already here. Ithaca Intersystems Inc., 1650 Hanshaw Road/RO. Box 91, Ithaca, NY 14850 607-257-0190/TWX: 510 255 4346 \s^ Ithaca Intersystems Inc. Micros for bigger ideas. / Editorial Photo 3: Sony's new 3V2-inch floppy disk and drive. Each double-sided floppy disk can hold up to 875 K bytes of informa- tion, unformatted. The recording density is 1.47 times that of the 5-inch disk. Atiast-theDYNATYPER TYPEWRITER INTERFACE!™ Turn your electric typewriter into a low cost, high quality hard copy printer. 1 year warranty DYNATYPER - Rochester Data's patented* Computer/Typewj Interface is the industry standard for typewriter output. o&l||Sta< Scfcry w S 2 minutes to initially install and 5 seconds to remove *Q|J(ace. You do not have to modify your typewriter. All iJcrary war- ranties and maintenance agreements on your typewriter will be honored. tp* Compatible with all power carriage return JApewriters having standard U.S. keyboard. The Dynatyper j^Stks with Selectrics (model 1) and most non-Selectrics (maps! 2). Please specify. Typewriter conversion between modejapakes 2 minutes and the kit (17 plungers) is available for a nornjoal fee. The Dynatyper is compatible with ^(♦major word processing software. (Scripsit, Pencil, Applewriter»£asywriter, Magic Window, Visi-calc CCADBM, Supertext, WriWStTn) Interfaces available for "WS-80, APPLE, PET/CBM, OSI, Northstar, HP-85, H-89. WeigljjMnly 3 lbs. Extremely portable. Delivery: StfHk towvo weeks. Price $499 for complete system. F.O.B. Rj^hellfer, Domestic. VISA and Master Card accepted. Ncky at 71 6-244-7804 Tlvfc'is a Jailer; Timing a registered trademark of Rochester Data 3000 Winton Road South, Rochester, N.Y. 14623 incorporated Osborne is currently seeking approval from the FAA to operate the unit on board a plane.) One quibble: the screen may be too small for some people's taste. Con- sulting Editor Mark Dahmke is preparing a full test report on this computer for an upcoming issue of BYTE. Update We have received numerous requests for more infor- mation on the Microterminal described in the January editorial. We cannot divulge any more information at this time, but watch for a complete report coming soon. Also in the works: full reports on the Commodore VIC-20 color computer; the TRS-80 color computer hi- res (high-resolution) graphics; a special issue on local net- works; reviews of three LISP packages; the new spelling- correction programs; Logo for the Apple II and TI 99/4; and our annual August language issue, this year on Smalltalk, one of the most exciting languages in the com- puter field today. Watch our upcoming editorials for fur- ther information about future computers. ■ The Carl Helmers Newsletter Readers of recent issues of BYTE are probably aware that Carl Helmers, former Editorial Director of BYTE, is now working on projects outside of McGraw-Hill. One of Carl's new undertakings is the Carl Helmers Personal Computer Newsletter, which will cover the present state of personal computing, future developments in hardware and software, artificial intelligence, mass storage, and many other topics. The newsletter will contain no advertising, cost $200 per year, and will appear monthly. Carl is also considering a free "personal computer industry conference call, " which would be made available via a toll-free 800 number if interest among subscribers is high enough. The setup would enable up to twenty people to participate in a regularly scheduled monthly "roundtable" discussion. For more information about subscribing to the newsletter, write to North American Technology Inc, Strand Building, Suite 23, 174 Concord St, Peterborough, NH 03458, or call 603-924-6048. We wish Carl luck in his new venture... CM BYTE's Bugs Invisible Software Review Because of a last-minute scheduling change, the prod- uct review by BYTE editor Gregg Williams, "The muSIMP/muMATH-79 Sym- bolic Math System" (Novem- ber 1980 BYTE, page 324), did not appear on the "In the Queue" page for that issue. We regret the omission. 10 April 1981 © BYTE Publications Inc Circle 7 on inquiry card. Getting the Number Straight In the February 1981 BYTE, on page 345 of the "What's New?" section, the telephone number given for General Digital Corporation was incorrect. The correct number is (203) 289-7391. We apologize for any difficulties that may have arisen due to the error. ■ Circle 8 on inquiry card. > Make the Apple II* a powerful IEEE-488 Controller in a snap. Just plug the SSM A488 board into any Apple II* expansion slot for a low-cost, full-featured instrumentation interface. SSM gives the Apple II the power and versatility of a $9,000 IEEE-488 controller. At a fraction of the price. Our board converts the Apple II into a truly sophisticated controller that programs and controls up to 15 different instruments connected together on the 488 bus. We make programming easy. The 68488 chip, designed by Motorola, forms the heart of our A488. We back this chip with powerful on-board firmware to give you system control via simple string commands. The only software you need is easy-to-program Applesoft* Basic. To develop special purpose firmware, simply replace our PROM with a RAM. With the A488, bus com- munications operate at top speed — without depending on software loops for timing. And like the more expensive IEEE-488 controllers, this system interfaces with more than 1200 instruments and peripherals. Suitable for OEMs as well as end users. Whether you make test/measurement systems for re- sale, or simply for yourself, the SSM/Apple combo gives you top performance. As it cuts your costs. Call your local dealer or SSM today for complete details. IEEE-488 bus cable (6 ft. with stackable connectors) Industrial grade circuit board PROM firmware for powerful user interface 68488 IEEE-488 controller chip. SSM's A488 board expands the Apple II to a high-performance IEEE-488 controller. * Registered trademarks of Apple Computer Inc. SSM Microcomputer Products, Inc. 2190 Paragon Drive San Jose, CA 95131 (408)946-7400 Telex: 171171 TWX: 910-338-2077 Letters Computers and Trees: The HHC Forest I read Gregg Williams and Rick Meyer's article about the Panasonic/ Quasar hand-held computers (January 1981 BYTE, page 34), and I could hardly contain my excitement over the potential use for these devices in my field: forest measurements and statistics. Forest inventory and survey work typically involves many man-hours in the forest collecting information on tree size, species, sawtimber quality and value, growth, etc. This information is normally hand-written on tally sheets in the field, and either hand-tabulated in an office or key-encoded for statistical summary and analysis by computer. Forest scientists and practicing foresters are continually looking for more economical methods of obtaining resource information at the level of precision required for complex management planning and decision- making. The HHCs (hand-held computers) ap- pear to have the capability of being used in the field as data-entry devices, thereby eliminating the need for subsequent key- encoding of hand-written information. With their alphanumeric capability, they should be able to store and manipulate descriptive text as well as numeric infor- mation. With suitable applications pro- grams, I would think they are also capable of handling a fairly large repertoire of forestry problems (eg: compiling tables describing timber volumes by species, log grade, and size class; estimating stumpage values for timber sales, etc). For larger data-processing requirements, they could transmit their data, through the modem attachment, to a host computer. In short, I see in these devices a potential for great- ly reducing the man-hours required for routine data-entry and processing applica- tions in forestery. George L Martin Jr Assistant Professor of Forest Biometry Department of Forestry College of Agricultural and Life Sciences University of Wisconsin 1630 Linden Dr Madison WI 53706 The advent of HHCs will be a boon to many who must perform data entry and sophisticated calculations in the field. Un- FINDING SOLUTIONS AND BEING COMPETITIVE IS OUR BUSINESS. Having problems and looking for a computer to help solve them? Are you finding computer dealers come in one of two ways? Either Full system support with Full price or Take it or Leave it with Low price. At Omega we don't believe that you should have to make a choice. Yes, we're in business to sell products but also, to solve your problems. Our prices will be the lowest possible. Our support and product quality will be second to none. Check out our Mail Order prices in this ad (our retail prices will be higher). See if you don't agree with our first claim. For our second claim, call us with your data processing needs and problems. Better yet, come in and see us. Finding solutions and being competitive is our business. We never forget either of them. tipple computer Authorized Dealer APPLE III SCALL APPLE II "PLUS" 48K S 1 169.95 HEWLET PACKARD 85 or 83 $ CALL APPLE II ACCESSORIES: Disk II with controller $ 535.00 Disk II 2nd drive 455.00 Graphics Tablet 665.00 Language System with PASCAL 395.00 Silentype Printer W/Int 526.00 Integer Firmware Card 1 52.00 Microsoft Z-80 Softcard 259.00 Videx videoterm 80 col Card 279.00 Sanyo 12" Green Monitor 269.00 Supplies: Scotch Diskettes - Best of Quality! price per box of (10) 744-0, 10. 32 $ 27.00 740-0 SS/SD Sector 31 .00 741-0 SS/DD Sector 37.00 743-0 DS/DD No Format 44.00 New Products: Videx L/C Adapter 1 10.00 Microsoft 16K RAM Card 169.00 D.C. Hayes Micromodem II 315.00 Novation DCAT Modem 195.00 EPSON MX-80 CALL Mail Order Terms of Sales: Price based on prepaid orders. NO COD's. Visa or Master Charge orders add 3% to purchase price. Allow 14 working days for personal and company checks to clear. Order under $100.00 add S3. 00 for shipping and handling. All orders (unless specified in ad) within Continential U.S. shipped U.P.S. no charge. APO or out of Continential U.S. write or call for shipping charges. All prices subject to change and all offers subject to withdraw! without notice. CA residents add 6% sales tax. OMEGA MIQFD 3CMPITEF8 The Problem Solving Company 3447 Torrance Boulevard • Torrance, California 90503 • (2131 370-9456 fortunately , neither the price nor the availability date of the Panasonic/ Quasar unit was announced at the CES (Con- sumer Electronics Show), as I had origi- nally hoped. As an educated guess, I would place the price in the $400 to $650 range, with the units possibly being avail- able as early as mid-1981.... GW Oddest Programming Language of Them All In the December 1980 BYTE, Mr Daniel Weise presented a version of a self-repro- ducing program. (See "Thief -Reproduth- ing Programth," page 16.) The following version of the same fundamental algo- rithm is written in my favorite program- ming language — English: Replace every occurrence of "x" in " x 'x'." by "Replace every occurrence of 'x' in 'x "x".' by ". Which executes as follows: Unquote " x 'x'." to obtain the form x "x". Replace "x" by the quoted substitute to obtain x "Replace every occurrence of 'x' in 'x "x". ' by ". Replacing x by the unquoted substitute we obtain Replace every occurrence of "x" in " x 'x . " by "Replace every occurrence of 'x in 'x "x". ' by ". The operations quote and unquote work as follows: Quote text = "text*". Unquote "text*" = text. where text* is a faithful copy of text, ex- cept for the replacement of each quote mark, single or double, by its comple- ment. This transformation is idempotent. This is a time-honored syntactic device of English. I leave it to you, dear reader, to judge the relative perspicuity of this English ver- sion and the LISP version provided by Mr Weise. James P Corbett 24 Sheffield Lane Florence MA 01060 Readers should note that they may not be able to get this program to run on every model of the human brain — which is probably just as well, since once run- ning, it would use up all available process- ing time and memory space. . . . CPF 12 April 1981 © BYTE Publications Ire Circle 9 on inquiry card. Circle 10 on inquiry card. Edison had over 1,800 patents in his name, but you can be just as inventive with an Apple. Apple is the company with the brightest ideas in hardware and software and the best support — so you can be as creative with a personal computer system as Edison was with the incandescent bulb. How Apple grows with you. With Apple's reliable product family, the possibilities of creating your own system are endless. Have expansion capa- bilities of 4 or 8 accessory slots with your choice of system. Expand memory to 64K bytes or 128K bytes. Add an A to D conversion board. Plug into time sharing, news and electronic mail services. Use an IEEE 488 bus to monitor lab instruments. Add 4 or 6 disk drives — the 5 'A" 143K bytes, high-speed, low-cost drive that's the most popular on the market. Apple speaks many languages. Since more than 100 companies create software for Apple, you'll have the most extensive library in the personal computer world. Want to write your own programs? Apple is fluent in BASIC, Pascal, FORTRAN, PILOT and 6502 assembly language. There's even a series of utility programs called the DOS Tool Kit that not only lets you design high-resolution graphic displays, but lets you work wonders with creative animation. More illuminating experiences in store. You won't want to miss all the Apple products being introduced at your computer store all the time. Don't let history pass you by. Visit your nearest Apple dealer or call 800-538-9696. In California, 800-662-9238. Or write: Apple Computer, 10260 Bandley Drive, Cupertino, CA 95014. cippkz computer inc. Letters Vive la Guerre I have a few comments on Bruce Car- brey's article "A Pocket Computer? Sizing up the HP-41C." (See the December 1980 BYTE, page 244.) The article was very in- teresting, since I use both an HP-41C and a TI-59 frequently. Mr Carbrey did a comparison that I had planned but had never done. On page 246, he states that storing a number in a register on a TI-59 requires three lines. This applied to the earlier SR-52, but only two lines are needed with a TI-59. Two is better than three, but the one-line approach of the HP-41C is better. It makes editing a program without a printer much easier, especially since you don't have to remember key codes. Mr Carbrey's benchmark test program does not, however, use the TI-59's strengths well. A major difference be- tween the calculators is that both label and absolute addressing exist on the TI-59, while the HP-41C uses only labels. Since the HP-41C program is compiled, it is not penalized. Using absolute address- ing in the TI-59 program cuts run time by 3 seconds and saves a step. Listing 1 is a benchmark program that YOU THINK YOU'VE SEEN WORD PROCESSING SOFTWARE? The magic wand; Word Processing System offers you the best features of any system in the micro market FEATURES INCLUDE: Full-screen text editor Simple, control key operation Edit programs as well as text Assemble, compile or run programs without modification Files larger than memory Files up to 256K Library files Merge part or all of one file with another Spool printing Print a file while editing another Easy page formatting Simple commands set margins, page length, etc. Override commands at run-time Give any command from the key- board as well as in file Variable pitch control Change pitch in mid-line, even mid-word Up to 128 user-defined variables String, numeric or dollar format Form letter generation from external data files Compatible with both sequential and fixed-record files Conditional commands Any command may be conditional Print to disk and/or printer Save all or part of output on disk Switch from specialty printer to CP/M list device Print the same file on either specialty or standard printer Version 1.1 is now available EASE OF OPERATION With all its power, the MAGIC WAND is remarkably easy to use. This is no acci- dent. The command structure is designed to be flexible and logical so that you can perform basic functions with a minimum of commands. We have included in the manual a step- by-step instructional program, for the per- son who has never used a word-proces- sor before. The trainee uses sample files from the system disk and compares his work to simulated screens and printouts. In addition to the lessons, the manual has a complete documentation of the command structure, special notes for pro- grammers, an introduction to CP/M for non-programmers and a glossary. The manual is typeset, rather than typewritten, for greater legibility. We have written the manual in non- technical English, because we want you to read it. We don't overload you with a bunch of jargon that could confuse even a PhD in Computer Sciences. We send out newsletters so that users of the MAGIC WAND can learn special applications of the print commands. For example, we might show you how to cre- ate a mailing list or set up an index for a file. In short, we've done everything we can to make things easy for you. Because the best software in the world is just a bunch of code if you can't use it. For more information , call or write: srciaW business ap^vcaXvoas, u\c. 3220 Louisiana • Suite 205 • Houston, Texas 77006 • 713-528-5158 CP'M is a registered irademarfc ol Digilai Research Core uses the TI-59's parenthesis feature. This seemed especially apt considering Hew- lett-Packard's and Texas Instruments' battle over Reverse Polish Notation vs Algebraic Operating System. My pro- gram is 10 steps shorter, uses 4 data registers, and runs in 33 seconds. This im- proved performance is achieved by reduc- ing the number of relatively slow memory arithmetic operations and utilizing the TI-59's stack. (Also note that the correct answer in Mr Carbrey's table 1, on page 254, is $17553.30, not $17533.30.) Listing 1 000 76 LBL 001 11 A 002 58 FIX 003 02 02 004 42 STO 005 01 01 006 91 R/S 007 42 STO 008 02 02 009 91 R/S 010 42 STO 011 03 03 012 91 R/S 013 55 ■j. 014 01 1 015 00 016 00 017 85 + 018 01 1 019 95 = 020 42 STO 021 04 04 022 45 Y* 023 43 RCL 024 02 02 025 94 + /- 026 65 X 027 43 RCL 028 01 01 029 85 + 030 53 ( 031 00 032 85 + 033 43 RCL 034 04 04 035 45 Y" 036 43 RCL 037 02 02 038 94 + /- 039 97 DSZ 040 02 02 041 00 00 042 32 32 043 54 ) 044 65 X 045 43 RCL 046 03 03 047 95 = 048 91 R/S Much has been made of the HP-4lC's plug-in accessories, but I wonder if they are really a major design change. They obviously follow TI's development of the printer attachment and Solid State Soft- ware. The HP printer has excellent print quality and features, but it is very slow. The Bar-Code reading "Warvd" is the only significant advance in my opinion. The capacities of the two calculators are about equal in my experience. Most users want both a printer and a card 14 April 1981 © BYTE Publications Inc Circle 11 on inquiry card. Circle 12 on inquiry card. Easy on your Eyes and your Budget 80 character display makes it ideal for word processing and scientific applications. America, Inc. 130 Martin Lane,Elk Grove Village, IL 60007 This high quality professional computer monitor provides sharp, clear display of up to 80 characters by 25 lines of text, making it ideal for word processing as well as standard business applications. Lightweight industrial grade construc- tion gives maximum portability with reliable operation. Letters reader, so only two memory modules can be added. Thus, a maximum of 830 pro- gram lines is available without data registers in practical applications, and this limit is quickly reduced. Even allowing for the HP-4lC's greater storage efficiency (I find a 50% improvement over the TI-59), the HP-41C is only marginally better. The lack of a TI response to the HP-41C threat mystifies me. Although users were surveyed last spring, no new product has appeared. The discounts being offered on TI's "59" calculators clearly suggest that something is coming soon, but it has been a year since the HP-4lC's introduction. Perhaps the pocket computers from Radio Shack and Sharp threw a wrench into the works. TI has always played a game of in- creased capacity at lower cost in the pro- grammable-calculator marketing wars. I await TI's next entry with great anticipa- tion. Users have profited immensely from the battles between Hewlett-Packard and Texas Instruments in this market. (Take out your old calculator and try using it now.) Vive la guerre!!! G John Garner 319 Blue Haven Rd Dollard des Ormeaux, PQ, Canada INTELLIGENT Eliminate The Data Comm Hassles of Outmoded "DUMB" Modems BIZCOMP's Intelligent Modem is new. Brand new. It teams a Bell 103-type "dumb" modem with a custom BIZ-080 microcomputer in an attractive desk-top enclosure. RESULT: Incredibly simple data comm for professional users. No more mad dash to get a handset into coupler muffs before being disconnected by the remote. No more exclusion-key telephone needed to do the dialing. No more outboard coupler boxes. And for computer sites, communications software written in high level language like BASIC or COBOL. How's that for simplicity! The 1030 gives you automatic dial, automatic answer and, unique to the industry, automatic REPEAT dial. The top-of-the-line 1031 adds command-selectable tone or dial pulse dialing for TWX net applications and self-test for ensuring full function- ality. Both models are FCC registered for direct connection and feature comm rates from 110, 134.5, 150, 200 to 300 baud. BIZCOMP's innovative Code-Multi- plexed Design enables complete control using a simple 3-wire RS-232 interface. Don't burden your customers with data comm hassles. Install a BIZCOMP Intelli- gent Modem today. BIZCOMP Communications... Why not start with the best? BIZCOMP Compollutlon P.O. Box 7498 • Menlo Park CA 94025 • 41 5/854-5434 Rentals and leasing available from Leasametric, 800/227-6773; 4151574-5797 In Calif. Patent Pending Steve Ciarcia's article "Electromagnetic Interference" (January 1981 BYTE, page 48) is a very good and long-overdue sum- mary of the electronic noise-pollution problem. Many radio engineers have been fighting the battle against the plastic com- puter box and the poorly designed digital boards that dominate the industry. We are ready for some stiff regulations regarding fundamentals, such as simple metallic shielding and grounding prac- tices, so that the rest of the world can con- tinue to use RF (radio-frequency) com- munications. One omission in Mr Ciarcia's article is the reference to a state-of-the-art hand- book or text for more comprehensive in- formation on the subject. One of the best comes from Bell Laboratories, in Henry W Ott's book Noise Reduction Techniques in Electronic Systems (New York: John Wiley & Sons Inc, 1976). R W Burhans Ohio University Avionics Engineering Center Athens OH 45701 This omission was caught and rectified. See "BYTE's Bits" March 1981 BYTE, page 314, for additional reading material. Also, see J N Demas's review in the September 1980 BYTE, page 311. ...GW Well-Rounded Machine We at Hewlett-Packard were very pleased to see Brain Hayes's excellent arti- cle on the HP-41C calculator. (See "The HP-41C: A Literate Calculator?", January 1981 BYTE, page 118.) He did make some statements that deserve clarification, however. In particular: There is something absurd about the world's fanciest calculator not being able to give results accurate to more than seven or eight decimal places. The example he used was the (-JT) computation, which is a good illustration of a common misunderstanding about computer arithmetic. When calculating \fT, the 41C works internally with 13 digits and then rounds correctly to 10 digits. This helps to insure the accuracy of the displayed result. But this result is still not really -Jl, merely the best representa- tion possible on this, or any other, 10-digit machine: 1.414213562. At this point, the calculator does not know where this number came from: it could be a previous result, or it could have been entered exactly as such through 16 April 1981 © BYTE Publications Inc Circle 13 on inquiry card. THE NEW RELIABLES Take a look at the new industry standard in reliability. Our warranty on all IMS International products is two years from the day a dealer sells them. Two years. The systems we offer are some of the most advanced in microcomputer history. That gives the IMS dealer another distinct advantage in his marketplace. There's more. Low retail cost— well under $10,000 complete— with the best margins and benefits in the industry. Face it, even the most impressive specifications are no replacement for profits. Next to profits, full factory support is the second most important feature we give the IMS dealer. Our systems are designed to meet the specific needs of your business computer today and tomorrow. The price/ performance comparison with competitors is one of an IMS dealer's easiest sales closes. Tailored sales plan. National advertising backup. Point of purchase program. Protected territories. Complete system delivery in 30 days. We have what you and your customer need. The package is complete. New. Reliable. For more information on our superior computer line and the unique dealer program that comes with it, call Fred Williams (collect) 714/978-6966, or write us: Box 201 2800 Lockheed Way international Carson City, NV 89701 Circle 15 on inquiry card. BYTE April 1981 17 NEW CATALOGUE LISTINGS FROM JOHN D. OWENS ASSOCIATES, INC. CAT 100 FULL COLOR GRAPHICS Complete S-100 color imaging system with high performance video FRAME GRABBER. 3 fundamental functions are + digitization of video input in real time + + image storage in dual-port, on- board memory + + + video input of buffered image in gray levels, NTSC col- or or RGB color. Discount price $1,875. Write or call for option descriptions and pricing, too numerous to list here. HOUSTON INSTRUMENTS HIPAD DIGITIZER Create your own graphics using either stylus or optional cursor. Excellent for architectural drawing, business graphs, schematics, free form drawing, etc. More accurate and easier to use than keyboard input or joysticks. "Stream mode" allows continuous placement of coordinate pairs on 11" X 11" pad using either stylus or optional cursor. For S-100 systems and also Apple, TRS-80, PET. Our discounted price $ 755. LDOS for TRS-80 USERS New operating system can support up to 8 drives (either 5V»", 8" or new Win- chester fixed disk) in any combination. Features include ISAM Accessing Tech- niques. Keyboard type ahead, graphics string packer, dated files and many, many more. Our discounted price $ 126. Manual only $ 25. DMA-DOS North Star 8" FLOPPY SUBSYSTEM A new operating system, completely CP/M® compatible that allows use of both 8" (Shugart single sided, double density via Tarbell controller) and 5'A" drives. Complete hardware, software package $1,910. TARBELL CPU Z-80 Features memory management hard ware that allows dynamic mapping of ; logical to 1 MB of physical memory in ~ 4K blocks. Supports an easy to use im- plementation of MP/M®. Either 2 or 4 MHZ, jumper selectable. TWO on p board RS232 ports will full handshaking s? capability; crystal controlled program mable timer. SEE OUR ADS ON PAGES 178 AND 179 JOHN D. OWENS Associates, Inc. 12 Schubert Street Staten Island, New York 10305 212 448-6283 212 448-2913 212 448-6298 Overseas Callers: Phone 212 448-6298 WE HAVE NO READER INQUIRY NUMBER. PLEASE WRITE OR CALL. Letters the keyboard. Squaring this number cor- rectly and rounding again yields 1.999999999. Any 10-digit calculator that does otherwise is either doing "funny arithmetic," or else is not telling you everything it knows. But the 41C has lived up to its claim: each calculation was per- formed correctly to 10 digits. Also, and at least as important, the behavior of the cal- culator is utterly predictable and repeat- able. A calculator is a tool, and, like any tool, it has its limitations. These limita- tions must be understood if the tool is to be used properly. The point is this: there exist sequences of calculations that will generate errors of any magnitude on any finite-precision arithmetic machine. Keep- ing this in mind, the "world's fanciest cal- culator," the HP-41C, is a tremendously powerful tool indeed. Steve Abell Research and Development Engineer Hewlett Packard Company Corvallis Division 1000 NE Circle Blvd Corvallis OR 97330 MIcroAce: More Power to Sinclair I disagree with John McCallum's state- ment in 'The Sinclair Research ZX80" (see the January 1981 BYTE, page 94) that by building the kit version "you will not save any money." My MicroAce cost a mere $150 — a savings of 25 % over the price of a ZX80. It was easy to build, although the instructions were not nearly as elaborate as Heathkit's. The MicroAce has room for two more programmable-memory integrated cir- cuits than the ZX80. The increase to 2 K bytes almost triples the possible program length (portions of the first 1 K bytes are used for "housekeeping"). This expanded capacity gives you a much more usable computer. Its unique design means that you can store as much information as other systems that use 3 K to 4 K bytes. I couldn't afford $500 or more for a computer, but, for about $175 (kit plus memory chips), I have learned quite a bit and gained much enjoyment while doing so. John R Mullen 8518 Terrang Ct Rockford IL 61111 The MicroAce kit is reviewed by Delmar Searls on page 46 of this issue. Calling Z8000 The "BYTELINES" section of the January 1981 BYTE (page 200) contained an item saying that Microsoft proposed a standard set of calling conventions speci- fying parameter-passing and register usage for the Z8000 microprocessor. It was actually Zilog Inc, inventor of the Z8000, that established the conventions. Zilog announced the Z8000 standards at last year's WESCON show in Anaheim, California. The announcement contained the statement that the conventions "have thus far been adopted by Microsoft and are under consideration by several other companies." Thank you, BYTE, for letting me set the record straight by pointing out that Zilog originated the Z8000 calling conventions that were subsequently adopted by Micro- soft. Bruce Weiner Product Marketing Manager Zilog Inc 10460 Bubb Rd Cupertino CA 95014 Why Didn't We Think.... -*\i ^ 1 mtgml METUflN I always look forward to the latest issue of BYTE, as I am sure many others do. I would like to pass along this suggestion to my fellow readers who use an Apple II computer. It is my solution to the well- known "accidental RESET" problem that plagues users of that machine. Manauba Sakuta, MD 6324 Wilryan Ave Edina MN 55435 December Adventure BYTE's "Product Reviews" of games in the December 1980 issue were absolutely perfect. There are too many bad programs on the market; being able to see a picture of the display (along with a description of how the game is played) is a big help. I noticed that BYTE didn't continue this policy in the January 1981 issue— I realize that you can't have seven game reviews in every issue, but it would be nice.... Thanks. PAD from Livermore CAB 18 April 1981 © BYTE Publications Inc Circle 16 on inquiry card. MountainNHardware MusicSystem TM MusicSystertn generates the sound of any musical instrument— leal or imagined! Solo or sextet. Rock or classical. Said-back or loud. At home or in the concert hall <|r classroom. MusicSystem sets new standards fortomputer generated music. Digital Synthisizer with 16 voices. Stereo output. I note sequen- nts. Wavetorms, envelopes, anil amplitudes are fully programmable for each voice to create instrument definitions and music dynamics. 32 Khz sample rate. Frequency resolution isjr.5Hz steps. Graphical input of sheet music on jjngh-resolution screen using standard music notation. Print out sheet music with a graphicsXprinter. Complete software operating system^Graphical music editor using light pen (pr^otfided), game paddles, or keyboard. Pre- entered music provided for immediate playing and enjoyment. Thorough documentation and tutorial user's manual. Drop by your Apple N Dealer and ask to hear for yourself. You'll know what we mean when we say MusicSystem is all the instruments anyone with an Apple can play! \ Available al Apple Dealers worldwide £» [Name (Address . Icity |Phone_ Mountain Hardware LEADERSHIP IN COMPUTER PERIPHERALS A Division of Mountain Computer, Inc. 300 Harvey West Blvd., Santa Cruz, CA 95060 (408) 429-8600 Music I can play? Send details. State_ Zip. "Apple is a trademark of Apple Computer, Inc. Recurrence in Numerical Analysis James J Davidson c/o BYTE Publications POB 372 Hancock NH 03449 Although Taylor's series are the most universally useful method of computing higher mathematical func- tions, they do have their drawbacks. In particular, many functions have representations only in the form of alter- nating series. This can cause great difficulty in maintain- ing accuracy if large arguments are required. Often, so many significant digits are lost in the process of computa- tion that the results are, at best, useless. At worst, if you do not suspect that gross inaccuracies are occurring, you may make severe engineering mistakes. If the various remedies such as argument scaling are in- effectual in improving accuracy, the only recourse is to seek alternate methods of computation. Of those alter- natives, recurrence relations have the widest applicabili- ty. What's a Recurrence Relation? Various functions have the mathematical property that if you know two consecutive values, you can use those to find a third. This process can be repeated to find a fourth from the second and third, and so on. Of course, you need to pick the right pair to start from, but if you do, you can get to any value you want. The simplest illustration of a recurrence relation is the Fibonacci series. This is a series of special numbers known in medieval times to Leonardo of Pisa, surnamed Fibonacci (1175-1230). Fibonacci numbers are found in botany and other natural sciences, as well as in certain mathematical theories of aesthetics. They are interesting in their own right, and there is at least one society devoted to study of their mathematical properties. The Fibonacci series proceeds in the following fashion: 0, 1, 1, 2, 3, 5, 8, 13, 21, 34, 55, . . . Each term is obtained by adding the two previous terms. As a formula, the series can be expressed as: a n *2 ~ H„+l + An where the initial terms must be specified as and 1. Once you get started, it is obvious that you can keep going in- definitely using the same formula. It is not even necessary to begin at the beginning. If you know the thirteenth and fourteenth terms, for instance, you can find the fifteenth by adding them together. Programming this recurrence relation is not going to be much of a chore. The important thing to keep in mind is that three values must exist within the computer simultaneously: the n and (n + 1) terms, and the sum of these two, which is the value being calculated. Then, after the value is found, it must be slid into the (n + 1) position, with that one being slid into the n position. This sliding process is the only tricky part because it must be done in the proper order, and it is the heart of all recur- rence programming. Listing 1 shows how simple the job is. After initializa- tion, the FOR... NEXT loop handles the calculation in 6 lines. The new term is calculated in line 160 and printed in line 170. The sliding process is done in lines 180 and 190. Note that Al must be slid into A0 before A2 is slid into Al; otherwise, Al will be lost. That, in principle, is all there is to programming recurrence relations. Forward and Backward Recurrence Recurrence relations have a property that on first ac- quaintance seems absolutely incredible: if you go in the "right" direction, you increase the number of significant digits in your answer with every new term. This means that in certain cases you can start out with a completely arbitrary guess and, if you go long enough, end up with eight or nine significant digits in your final result! On the other hand, if you go in the "wrong" direction, you lose digits with each iteration and end up with garbage. There is nothing at all mysterious about this property. If you think about the Fibonacci series, you will realize 20 April 1981 © BYTE Publications Inc Ciilllotnla Computer Sy items Syattm 200 mam CCS. MAKING MINIS OUT OF MICROS. Here's the CCS line of board-level computers for system builders on the move. Push In the CCS board. And push on with your application. 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You buy exactly what you need. But you can easily expand later. We'd like to tell you more about the CCS line of board-level com- puters, OEM systems, and computer systems. There's a lot more to tell. Send in the coupon for more information, contact your local computer dealer, or call. |o Please have a sales representative I call me. lo Please send more information on CCS Board-Level Computer Modules. | Name I Company , Address City/State/Zip . i Available Quarter 2, 1981. ■ For use with CCS System Models 200, 300, 400, | Phone ( 'q >. California Computer Systems 250 Caribbean Drive Sunnyvale, California 94086 (408) 734-581 11 that that is exactly what happens there. Starting with two numbers one digit long (0 and 1), you can build up after thirty or forty terms to as many digits as your machine will hold. For this case, we are going in the right direction because the answers get progressively larger as we calculate each new term. In this case also, we are moving in the direction of in- creasing index, n. This is called forward recurrence. If we were to start out with a high-order pair of terms and calculate down towards zero, that would be called Listing 1: The Fibonacci numbers through recurrence. The Fibonacci numbers are used here to demonstrate how easy it is to program a recurrence relationship. All that is necessary is to keep proper order in the calculation and the shifting of variables. 0010 REM 0020 REM *** FIBONACCI NUMBERS 0030 REM *** BY RECURRENCE RELATION. 0040 REM 0100 INPUT "HOW MANY FIBONACCI NUMBERS",N 0110 A0 = 0120 PRINT A0 0130 Al = l 0140 PRINT Al 0150 FOR 1=1 TON 0160 A2 = A1 + A0 0170 PRINT A2 0180 A0 = A1 0190 A1=A2 0200 NEXT I 0210 END Listing 2: A Taylor's series program for the Bessel functions. Lines 160 thru 190 calculate the first term. (Line 160 should not be necessary, but many BASlCs insist on executing a FOR. ..NEXT loop at least once, regardless of index and target.) This program is not recommended if the argument will ever ex- ceed about five or ten, depending on your BASIC. 0010 REM 0020 REM *** BESSEL FUNCTIONS, FIRST KIND, INTEGER ORDER 0030 REM **' BY TAYLOR'S SERIES. 0040 REM 0100 INPUT "ARGUMENT", X0 0110 INPUT "ORDER", N 0120 X = X0/2 0130 X2 = X*X 0140 S = 0150 T=l 0160 IF N = THEN 200 0170 FOR 1 = 1 TON 0180 T = X/I*T 0190 NEXT I 0200 FOR I = 1 TO 999 0210 S = S + T 0220 T=-X2/I/(N + I)*T 0230 IFSoS + TTHENNEXTI 0240 PRINTS 0250 END Of the various mathematical func- tions that can be calculated by recurrence, the ones with the greatest engineering utility are the Bessel functions. backward recurrence. For the Fibonacci series, backward recurrence is "wrong" (because you lose significant digits) and forward recurrence is "right" (because you gain them), but for some other functions the reverse is true. Putting it another way, if you lose digits going one way, it is because (and only because) you are subtracting nearly equal large numbers. Avoidance of that situation is one of the cardinal principles of numerical calculation. In this case, avoidance consists simply of going in the op- posite direction, in which case you are adding the numbers instead of subtracting them. But how do you know which direction to go in? Very simply, look in a mathematics handbook. If that fails, and you have no knowledge of function behavior to guide you, trial and error is a solution. Set the program up for forward recurrence (which usually is easier) and see whether the terms get larger or smaller. If they get smaller, you guessed wrong. (Be sure that the decrease is not just local. Unfortunately, global function behavior must be known before you can be fully certain that you are going the right way.) Bessel Functions Of the various mathematical functions that can be calculated by recurrence, the ones with the greatest engineering utility are the Bessel and the Bessel-related functions. This is fortunate because many of these are strictly alternating series with no hope of argument scal- ing, and large arguments always seem to be the ones of greatest interest. The family of Bessel functions includes many varia- tions. There are the first, second, and third kinds; in- teger, fractional, and noninteger orders; and regular and modified types. The related functions include Kelvin, Airy, and Ricatti-Bessel. For now, though, we will be concerned exclusively with regular Bessel functions of the first kind, and of integer order. These arise as solutions of Bessel's differential equation: x*-pf- + x-&- + (x» - n 2 )y = dx l dx This equation appears in a wide variety of engineering and scientific problems, such as heat transfer and mem- brane vibrations. It also shows up indirectly in the analysis of frequency-modulated signals. Any time cylin- drical coordinates are used in analysis, Bessel's equation is almost certain to be involved somewhere. As a conse- quence of that fact, Bessel functions are also called (par- ticularly in German) cylinder functions. Let us see where the problem lies in computing these functions by Taylor's series. The Taylor's expansion is: lm = (t) VJ-r)*(- i!(n + i)! ) This is clearly a strictly alternating series, and the critical 22 April 1981 © BYTE Publications Ire Circle 18 on inquiry card. IIM SYSTEM PERFORMANCE 31 MByte Formatted Capacity The ADES S33 MByte Hard Disk Subsystem is the HARD EDGE in System Performance. The S33 transforms your S100 computer from a slow, floppy-bound machine into a high performance system. The S33 is a complete subsystem which includes the ADES PS100 S100 compatible hard disk controller card, the Priam DISKOS (TM) 3350 hard disk, an attractive desktop cabinet, power supply, CP/M* BIOS software, and ribbon cable. With its 31MB formatted capacity and a CP/M data transfer rate greater than 40K bytes/second the S33 can instantly increase the performance of any S100 computer system. S33 FEATURES. The PS100 single card controller, which is IEEE-S100 compatible, contains an on-board processor, a 528-byte host interface RAM, and the hard disk interface. It has a fifteen command repertoire, on-board CRC to guarantee data integrity, user selectable base address, bank select feature, phantom RAM disable, and full S100 interrupt capability. It controls up to four Priam drives. In addition, the S33CBI0S software package allows easy integration into most CP/M systems. Application notes cover CBIOS integration and system boot directly from the hard disk. *CP/M is a registered trademark of Digital Research EXPANDABILITY. With the S33 subsystem, you have freedom to grow in two different directions. First, the PS100 con- troller supports all Priam 8- and 14-inch hard disk drives, including the 68 MByte and 158 MByte models. As your database expands, so does your system's capability. Second, one PS100 controller handles up to four drives of any size and in any combination, providing a full range of capacities. The S33 is only the first In the expanding line of ADES mass storage products. When you need an edge on your competition or more power in your personal system, look to ADES for the "HARD EDGE in System Performance." HDES ADAPTIVE DATA & ENERGY SYSTEMS 2627 Pomona Boulevard • Pomona, CA 91768 Phone: (714) 594-5858 Figure 1: The Bessel function of argument 10 and variable order v. When progamming a recurrence relation, information such as this is needed to determine whether to use backward or forward recurrence. Since the function goes to zero for large orders (values of v), we conclude that we need to use backward recurrence to achieve good accuracy. The Bessel function behaves similarly for other arguments: as soon as the order (v) exceeds the argument (x), the function rapidly declines to zero. Terminal sale. Display format 24 x 80—128 ASCII character set. Selectable transmission up to 19.2K baud. RS 232 interface. Typewriter standard type keyboard — 59 keys. *525each. Completely refurbished by Western Union, ADM3 terminals built by Lear Seigler, available at a price considerably lower than any other refurbished units you can buy. Act now and get advantages few can offer! • 90-day warranty. • National service network. Interested in other models? Also avail- able are the 33KSR, GE Terminet 300 and GE Terminet 1200. Write on your letter- head to Jim Chenard, Western Union, Dept. A, One Lake Street, Upper Saddle River, NJ 07458. Or call (201) 825-5333. western union *In quantity. argument occurs at x = 2. But it is rare that one is satisfied with values that small. Listing 2 is the program for this series. Keep in mind that the magnitude of the Bessel function can never ex- ceed unity, and see where your machine starts to bomb. If you have double precision, you may want to see how much difference it makes. Recognize, too, that a range of 10 38 can be a real limitation. For x = 100, the largest term nearly reaches 10 41 . Depending on your BASIC, a max- imum argument of five to ten is recommended. Bessel Recurrence Relation Now to recurrence. The relation we will use is: /„ +1 to = (2n/x)]Jx) - J„.i(x) and the first thing we need to know is which direction to go. This is a recurrence in order, not argument, so the question is whether the function increases or decreases as the order gets larger and the argument stays constant. Figure 1 (from the National Bureau of Standards hand- book) answers this clearly. At large positive arguments, the function heads toward zero. This means that, when we want to calculate J„(x) for a given n, we must calculate higher-order values of J(x) and use the recurrence formula to calculate down to order n. The next problem is where to start. This is quite an in- volved question, and, unfortunately, there are no established answers. Let us suppose we want to calculate / 8 (22). We have to start someplace above eight, but where, and with what? If we knew, for example, 7, 8 {22) by calculation, we would probably just as easily know / 8 (22) by calculation and 24 April 1981 © BYTE Publications Inc Circle 19 on inquiry card. Circle 20 on inquiry card. COLOR GRAPHICS Takes your PET ", CBM " or TRS-80" into the future Our VDP color board features 256 x 192 pixel resolution, 15 exciting colors on 5 planes producing 3-dimensional graphics and true animation, standard composite video output to either T.V. set or monitor (through optional R.F. Modulator) Plus 3 channel digitally synthesized self. No technical expertise required. 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Want to add and subtract, multiply or divide? Insert the Math Master Smart Disc. Other Smart Discs enable you to sort long lists, prepare per- sonalized standard letters and even keep track of your^ timekeeping. The No Problem Trial When Lanier places a No Problem typewriter on trial we do more than plug it in and leave. We help you become more productive the first day. The No Problem typewriter has proven itself in thousands of offices from coast to coast. We'll show you how it works with your applications in your office. So ■why wait? The Lanier No Problem typewriter is available today, to solve today's office problems. Send this coupon to set up an immediate appointment or call: (800) 241-1706. Except in Alaska or Hawaii. In Georgia, call collect (404) 321-1244. I 1 Yes, I'd like to know more about the No Problem Trial Offer! Name Title UINIER Phone . Best . Time To CalL Firm Name Address City State- County. _Zip_ What kind of typing or word processing system are you using now? Lanier Business Products, Inc. 1700 Chantilly Dr. NE, Atlanta, GA 30324 _ _4_81_ B C 1_ 'Trial charges may be applied toward your No Problem typewriter purchase. ©1981 Lanier Business Products, Inc. The No Problem Typewriter. It does more than just type. RETURN POSTCARD AVAILABLE- BACK OF BOOK. BYTE April 1981 27 Listing 3: Generating Bessel functions by recurrence. This one is slower than Taylor's series for small arguments, but is vastly more accurate for large ones. Within the accuracy range of a machine, no limit has been found on maximum order or argu- ment. 0010 REM 0020 REM ** ORDER 0030 REM *" 0040 REM 0100 0110 0120 0130 BESSEL FUNCTIONS, FIRST KIND, INTEGER BY RECURRENCE RELATION. INPUT "ARGUMENT", X0 INPUT "ORDER", N X = X0 IF ABS(X)<1.E- 10THENX = 1.E-10 0140 Y = X 0150 IFN>XTHENY = N 0160 N9 = INT(Y + 3*SQR(X) + 9) 0170 J9 = 0180 J8=l.E-30 0190 S = 0200 FOR I = N9 TO STEP - 1 0210 J7 = 2*I/X*J8-J9 0220 79=78 0230 J8 = I7 0240 IF INT(I/2) = 1/2 THEN S = S + 2*J9 0250 IFI = NTHEN J = J9 0260 NEXT I 0270 S = S-J9 0280 J = I/S 0290 PRINT 7 0300 END the data, he derived a fairly simple equation which errs conservatively by about ten percent in the region N=4X. The equation is as follows: N9 = int(max(N,X) + 3-JJC + 9) which is implemented in lines 140 thru 160 of listing 3. Program Comments If you have followed the discussion to this point, the program in listing 3 should be straightforward. Lines 140 thru 160 calculate the starting order, and lines 170 thru 190 do the initialization. Note that the arbitrary guess for J8 (]„(x)) is 1.0 X 10" 30 . It is chosen small (and can be much smaller if your range goes to 10""), so that large arguments can be accommodated without overflowing the normalizing sum. J9 (J„+i(x)) is initialized to zero, which reflects the assumption that the next higher term is too small to be significant. The recurrence loop (lines 200 thru 260) includes the normalizing sum at line 240. Line 250 picks out the par- ticular order you specified and stores it as variable J. After exiting from the loop, line 270 subtracts a zero- order term from the sum, and line 280 divides the chosen value by S to normalize it properly. One fact has not yet been mentioned: the recurrence relation involves a division by x, so that x = causes an error message. But this is a perfectly legitimate argument at any order, so line 130 assigns a small value instead. It cannot be too small, though, or overflow will occur rapidly because of that division by x. 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"Attractive Dealer & OEM Prices" See your nearest computer dealer, or contact us for the complete story on The 2nd Generation. a Division of MEASUREMENT systems &. controls incorporated 1601 Orangewood Ave. / Orange, Calif. 92668 (714) 633-4460 TWX / TELEX: 678 401 TAB IRIN See us at the sixth Computer Faire, booth 1526, San Francisco April 3-5 Altering this program to give a complete array of Bessel functions of various orders for a given argument is easy. Simply define an array of dimension N + 1 and start storing values when the variable I becomes equal to N. At the end, each value must be divided by S. You will find that execution time for this program is quite long. For small x, the Taylor's series is much faster and therefore may be preferred for arguments that are guaranteed restricted. When in doubt, use the recurrence method (listing 3). Negative Orders Note from figure 1 that the behavior at negative orders is very different than that of positive orders. So, instead of trying to adapt listing 3 to handle negative N, use the absolute value of N for N and transform the output by the relationship: Ux) = (-1)" x L(x) How Accurate Is It? There is only one practical way to check accuracy on a routine like this: compare the results against known values in a published table. But that creates a problem because available tables give out before the program does. The massive compilation by the staff of the Har- vard Computation Laboratory (Harvard: 1947) goes up tox = 100andn = 135. The most sensitive test, though, is to check in the region of the zeros at various orders. The Bessel functions look like damped sine or cosine waves, crossing zero at AOSOn A NOVA® 4/X? Wild Hare's MTSS Provides NOVA® Users With Multi-User Capabilities DG users now have a choice when upgrading to a mul- ti-user environment. Previously, the only way to support a true multi-user environment was to upgrade to AOS, but not anymore. MTSS provides all of the standard RDOS features for up to 16 users simultaneously and each user is totally in- dependent. Users may edit, compile and execute pro- grams written in FORTRAN IV, FORTRAN V, ALGOL. BASIC, MACS, etc. This means no software rewriting is necessary. No new operating system need be instdlled. More importantly, MTSS supports all NOVA-'s as well as ECLIPSE "'s so no expensive hardware upgrade is k required. Now Data General Users Have A Choice! HAKE P.O. Box 3581 , Boulder, Colorado 80307 (303)422-1182 The most sensitive test is to check In the region of the zeros of the function. intervals that look as though they might be periodic. (However, they aren't and the exact locations of the zeros is of considerable interest to mathematicians.) Obvious- ly, if you put in an argument that is supposed to be at a zero of the function, you expect to get a result of zero. This is unlikely for two reasons: • The locations of the zeros are transcendental numbers and cannot be specified exactly. The theoretical result, then, should not be exactly zero. • Backward recurrence is "right" only when the function increases as you proceed in that direction. But at a zero, the function suddenly nosedives down (see figure 1). Here, (2n/x) X J n (x) is supposed to equal J„*i(x), so their difference is zero. This is subtraction of nearly equal large numbers, which usually results in a small truncation er- ror. For the above reasons, all errors and inaccuracies ac- cumulate at the zeros. In particular, truncation errors show up flagrantly here. Not only does truncation cause the output to be nonzero, it actually translates the ap- parent location of the zero to a lower value. The trunca- tion is not really bad (it usually affects only the last digit), but those interested in the mathematical properties of Bessel functions should be aware that this bias does exist. With that background, we can state that the accuracy of the program of listing 3 on a nine-digit truncating BASIC is seven to eight decimal digits. Note that I said decimal digits, not significant digits. As far as I can deter- mine, the seventh digit after the decimal point is good to within one count anyplace, including zeros. Away from the zeros, the eighth digit appears good to within one count. This includes any xornup to one hundred, based on spot and systematic checks against the Harvard tables. Using the Royal Society tables of zeros, further checks can be made under worst-case conditions. For example, the forty-eighth zero of order 19 occurs at • = 178.846699. The actual output there is 7.6 X 1CT 8 , which will cause the seventh digit to be off by one count. Worse errors may be possible, but this one is the largest I found. Other BASICs with fewer digits should have similar properties: about a two-digit loss as long as the range is not exceeded by the normalizing sum. For engineering use, this should be entirely adequate. ■ References 1. Abramowitz, M and I A Stegun. Handbook of Mathematical Func- tions with Formulas, Graphs, and Mathematical Tables. Washington: National Bureau of Standards, 1964. 2. Harvard Computational Laboratory Staff. Tables of the Bessel Functions of the First Kind. Cambridge: Harvard University Press, 12 volumes, 1947 and following years. 3. Olver, F W J (editor). Royal Society Mathematical Tables, Volume 7: Bessel Functions Part III, Zeros and Associated Values. New York: Cambridge University Press, 1960. 30 April 1981 © BYTE Publications Inc Circle 23 on inquiry card. ^■>S ^§yj| ■ I --- i ml Ml Mb I iia ! ■"- " Atari &Appl< ilc" software. A financial VP in Massachusetts is cutting the time it takes to prepare month-end reports from three days to three hours. A California company is replacing most of its time-share computer service with a personal computer and VisiCalc, saving at least $30,000 the first year. 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It's designed for a non-programmer, and has an extensive, easy- to-understand instruction manual. Users also like solving a wide variety of problems with VisiCalc . . . and solving them their way. VisiCalc can even justify the cost of a personal computer, according to a New Hampshire financial analyst: "VisiCalc is paying for itself over and overf' VisiCalc is available for 32k Commodore PET/CBM, Atari 800 and Apple disk systems. VisiCalc is written by Soft- ware Arts, Inc. See VisiCalc at your Personal Software dealer. For your dealer's name, call Personal Software Inc. at 408-745-7841, or write 1330 Bordeaux Drive, Sunnyvale, CA 94086: While there, see our other Pro- ductivity Series software: Desktop Plan and CCA Data Management System. They're like time on your hands and money in the bank. See us In Chicago at NCC, booth 881 Programming Quickies Apple Name- Address Gary Stotts, 10390 Owens Cr, Broomfield CO 80020 Name-Address is a program that will store up to 100 names, addresses, and telephone numbers. It is written for the Apple personal computer and requires one disk drive. The program is organized as a binary tree so that names can be entered in any order and stored in alphabetical order. A larger number of names and ad- dresses can be stored by changing the DIM statements in lines 30 thru 90. The program first asks if there is an address file. Next the menu appears as follows: 1 - Add a Name 2 - List a Name 3 - List All Names 4 - Change a Name 5 -End DISCOUNT PRICES APPLE II COMPUTERS 16K APPLE II 1089.00 32K APPLE II 1134.00 48K APPLE II 1179.00 DISK W CONTROLLER 545.00 DISK ONLY 475.00 APPLESOFT CARD 159.00 INTEGER CARD 159.00 PASCAL SYSTEM 425.00 SILENTYPE PRINTER 525.00 RAM MEMORY FOR TRS-80, APPLE I 16KSET4116's 45. 0C NORTH STAR COMPUTERS HRZ-1D-32K-ASM 2125.00 HRZ-2D-32K-ASM 2475.00 HRZ-1Q-32K-ASM 2375.00 HRZ-2Q-32K-ASM 2990.00 VERBATIM DISKETTES BOX OF 10 5'A" 29.50 BOX OF 10 8" 39.50 FREDERICK COMPUTER PRODUCTS MUNICIPAL AIRPORT FREDERICK, MD. 21701 (301) 694-8884 The required entries to add or change a name-address record are the name, the street address, the city-state-zip, and the telephone number. To list any one address, enter the name. The name must be entered as last name first with no commas. Option 5, "END", will always create a new name-address file . ■ Listing 1: Name- Address— a program for the Apple II that will store up to 100 entries, as shown here. More entries can be stored by changing the DIM statements in lines 30 thru 90. DIM NtClOO) DIM A* < 100) DIM B*t 100> DIM LUC 100) DIM RY. ( 1 00 > DIM P*( 100) DIM 8%C50) : REM REM REM REM 100 1 10 120 130 CHR* LEFT LINK ARRAY RIGHT LINK ARRAY PHOME * ARRAY STACK ARRAY PRINT DtT"DPEN NAMAOR. CALL - 93G: INPUT "IS IF Y* ■ "N" THEN 200 PRINT D*T"READ NOMADR" INPUT E FOR | * 1 TO E INPUT N*U>! INPUT A*< I ) INPUT B*( I ) : INPUT P*( 1 ) INPUT rw. r J ) next PRINT CALL PRINT PRINT PRINT PRINT PRINT PRINT IF Ml - 93G: print tab "1 - ADD A NAME" "2 - LIST A NAME" "3 - LIST ALL NAMES" "4 - CHANGE A NAME" "5 - END" I INPUT " ENTER YOUR SELECTION ' I DR Ml > 5 THEN 2G0 0.930. 1120. 1340 NAME/ADDRESS PROGRAM" n*:ni PRINT 410 420 430 440 450 460 470 500 510 520 530 540 550 5GO 570 5Bn 590 600 BIO 620 630 ON Ml GOSUB 320.72 GOTO 200 REM REM (\DD A NAME SUBROUTINE CALL - 936: PRINT TAB! 7)T"ADD NAME RECORD" - E + IT REM FIRST EMPTY POSITION IN LIST - I : REM START SEARCH AT ROOT INPUT "ENTER NAME "TNI* IF LEN (Nl*) < 1 THEN 350 INPUT "ENTER STREET ADDRESS "Tnt« IF LEN (Alt) '. 1 THEN 370 INPUT "ENTER C ITY-STATE-2I P "IB1* IF LEN (81*) < 1 THEN 330 INPUT "ENTER PHONE NUMBER "IPl* REM IF NAME IS LARGER THAN I TH . SEARCH RIGHT BRANCH IF Nl* > N«( I ) THEN S00 IF Nl* < > N«(I) THEN 4BO PRINT "DUPLICATE NAME" INPUT "ENTER C TO CONTINUE "IC* RETURN REM IF LEFT LINK NOT NULL. SEARCH LEFT BRANCH IF LX(I) < > THEN I = LY.(I): GOTO 430 REM HANG NEW LEFT LINK ON PRIOR Y. ( I ) - E l*(E) - Nl*: REM FILL NEW RECORD LX(E) ■ RXIE) ■ P*(E) = PI* RETURN REM IF RIGHT LINK NOT NULL. SEARCH RIGHT BRANCH IF RY.(I) < > THEN I » RX(I>: GOTO 430 REM HANG NEW RIGHT LINK ON PRIOR RX C I ) N*(E) 660 LXIEt G70 RX(E) Nl* ■ REM FILL RECORD 6B0 690 700 710 720 730 740 750 7B0 770 760 790 Pli P*(E) RETURN REM REM LIST A NAME SUBROUTINE CALL - 936: PRINT TAB( 7K"LIST A NAME/ADDRESS" PRINT : INPUT "ENTER NAME TO LIST ";N1* IF LEN (Nl*) < 1 THEN 720 I = 1 IF Nl* > N*( I ) THEN 870 IF Nl* < > H*fl) THEN B50 PRINT N* < I > : REM FOUND PRINT A*(I> PRINT BS1I) PRINT P*(I) PRINT : INPUT "KEY RETURN REM SEARCH LEFT IF LY. II) < > THEN I REM SEARCH RIGHT IF RY. ( I) < > THEN I REM PRINT "NAME NOT FOUND" RETURN REM TO CONTINUE L7.( I > : GOTO 7B0 RY.( I I : GOTO 760 Listing 1 continued on page 34 32 April 1981 © BYTE Publications Inc Circle 25 on inquiry card. Circle 26 on inquiry card. d 1 % Hi* How to tell if it's a White Computer. (Users 2 through 16 — multiuser expansion with high performance through distributed processing.) Look for a single user CP/M® system that ex- pands to multiuser configurations economically. Look for independent 6 MHz Z80B-based User Modules with 64Kof RAM memory, each module with a port to the user terminal capable of handling baud rates of up to 38K under program selection. Look for high-speed block data transfers from user modules to the Global Processor for disk storage. That way, CP/M programs run independently for each user. Fast. And each users's station acts just like the fastest standalone system — no delays, no waiting for other users. Look for a Z80-based Global Processor for disk and tape I/O that transfers data from disk to user modules at the data transfer rate of the peripheral device. And a controller that handles as many as 8 SMD disk drives for up to 528 megabytes of hard disk storage, plus up to four 8" floppies, plus op- tional streaming tape backup. And look for a Z80-based General I/O Processor that supports up to eight printers — with 64K bytes of independent buffer memory. That's part of how you tell if it's a White Com- puter. There's a lot more. Here's a number and address for more information. CP/N is a registered trademark of Digital Reseach. Z80, Z80A, Z80B are registered trademarks of Zilog Corporation. White Computer Company A 1876 Industrial Way Redwood City, California 94063 A 415 364 7570 High Technology We make our competition obsolete with Information Master.™ Information Master™ is the sophisticate of software packages, but it also speaks your language. Its uncomplicated English- speaking design makes it easy to learn. No programming knowledge is necessary. Put it in your Apple II*, and you're ready to go. High Technology's Information Master organizes and prints everything from mailing lists to stock market data. Specify what records to store, type in the informa- tion, and Information Master organizes, calculates, stores and reports. Design your own reports and labels. Information Master is revolutionary in its adaptability and comes with a simple step-by-step instruc- tion manual. Its screen layouts are designed to show you maximum information for easy operation. Information Master is so smart it stops mistakes that our competition lets you make. If your computer dealer doesn't have Information Master, see one who does. High Technology's perfect complement to Information Master, Data Master, ,M allows you to change your mind months later without redoing all the work you've already done. Ask about it! Technology, Inc. Software Products Division P.O. Box B-1 4665 8001 N. Classen Blvd. Oklahoma City, Okla. 731 13 405 840-9900 'Apple II is a trade name of Apple Computer, Inc Programming Quickies. Listing 1 continued: 920 930 940 T * 950 SX( 3G0 IF 970 T = EM LIST ALL NAMES SUBROUTINE ■ ULl ■ o:t ■ o: call - 93B p: rem push stack THEN P - L*/.

: GOTO 940 1 990 990 1000 1010 1020 1030 1040 1050 10GO 1070 1090 1090 IF T ' =0 THEN INPUT "ENTER C TD CONTINUE " :C»: RETURN : REM ALL NAME FOUND ' - SX: REM POP 9TACK PRINT N«

: REM PRINT NAME PRINT A*(P> PRINT B*(P> PRINT P*(P) PRINT LI • LI + S IF LI = 20 THEN LI = 0! INPUT "ENTER C TO CONTINUE "!C* I 1 I 30 1140 1 150 ' - RV.

: REM CHECK FOR RIGHT LINK GOTO 940 REM REM CHANGE AN ADDRESS CALL - 93G: PRINT TAB< 7): "CHANGE A NAME/ ADDRESS" INPUT "ENTER NAME TO CHANGE "INI* IF LEN (Nl*) : 1 THEN 1120 I * 1 IF NI* '• N*l I ) THEN 1310 IF Nl* ■ > N«tl) THEN tZSO PRINT "OLD ":A* input "new ":oi) < 1 THEN 1190 PRINT "OLD ";B*(I> INPUT "NEW ":B*(I> IF LEN (B*(IH < I THEN 1220 PRINT "OLD "fF*tI> INPUT "NEW ";p*m PRINT RETURN REM SEARCH LEFT IF L7. (I 1 < > THEN I ■ I REM SEARCH RIGHT IF R'/.(I) ' •• THEN I * GOTO 11 GO REM REM EOJ PRINT D*T 1350 1 360 1370 1380 1390 1400 1410 112 PRI it D»: PRINT D«: PRINT E FOR I = 1 PRINT NT.( NEXT PRINT [>*: END DELETE NAMADR" OPEN NAMADR" 'WRITE NAMADR" PRINT n*( I 1 PRINT B*tl): PRINT P* ( I > : PRINT LRd)! PRINT R«(I] A Graphic Execution Display R B Minton, 8617 E Stearn Lake Dr, Tucson AZ 85730 I wrote a program for my Ohio Scientific Superboard to compute artificial satellite orbits and noted it ran slower and slower as time and the number of orbits pro- gressed. It occurred to me that I could graphically display how fast the program was executing and find out where it was slowing down by adding some extra code. Every 20 lines or so, I inserted K9 = K9 + l:GOSUB 2000, and then at the end: 2000 S9 = 54244 2010 POKE S9 + K9, 48 + K9 2020 FORZ = lTO30:NEXTZ 2030 POKES9 + K9,32 2040 IFK9 = 9THENK9=0 2050 RETURN This flashes the numbers 1 thru 9 from left to right on the bottom row of the video screen every time the main portion of the program loops. You can easily note the delay between certain numbers; this helps to pinpoint where the program is spending most of its time. The troublesome area or line can be further narrowed down by adding more GOSUBs, or by moving those from the faster part to the slower part. (Be sure that there are nine GOSUBs and that each is executed only once within the loop.) This method alerted me to a poorly written line of code I would have otherwise never suspected. ■ 34 April 1981 © BYTE Publications Inc Circle 27 on inquiry card. Circle 28 on inquiry card. TRS-80* Model I Computer Owners . . . Double-density storage, It's really here! Here at Percom. And your authorized Percom dealers. And double-density storage is here in a big way. Because now you can choose from three different levels of mini-disk systems — all double-density rated. And get the stojrage that precisely meets your application needs. Not to mention tlje service and quality that's made Percom the industry leader. Although rated for double-density operation, all levels of Percom drives work equally well in single- density applications. You can operate these drives in ordinary single- density format using TRSDOS* Percom OS-80™ or any other single-density operating system. Or, you can add a Percom DOUBLER™ to your Tandy Expansion Interface and store data and programs in either single- or double-density format. Under double-density operation, you can store as much as 350 Kbytes of formatted data — de- pending on the drive model — on one side of a five-inch minidiskette. That's four times the capacity of standard 35-track Model I mini- disks, almost 100 Kbytes more than the capacity of the eight-inch IBM 3740 format! Available in 1-, 2- and 3-drive configurations in all three model lines, Percom burned-in, fully- tested drives start at only $399. TFD-40™ Drives TFD-40 Drives store 180 Kbytes (double-density) or 102 Kbytes (single-density) of formatted data on one side of a 40-track minidiskette. Although economical- ly priced, TFD-40 drives receive the same full Percom quality control measures as TFD-100 and TFD-200 drives. TFD-100™ Drives TFD-100 drives are "flippy" drives. You store twice the data per minidiskette by using both sides of the disk. TFD-100 drives store 180 Kbytes (double- density) or 102 Kbytes (single-density) per side. Under double-density operation, you can store a 70- page document on one minidiskette. TFD-200™ Drives TFD-200 drives store 350 Kbytes (double-density) or 197 Kbytes (single-density) on one side of a minidis- kette. By comparison, 3740-formatted eight-inch disks store only 256 Kbytes. Enormous on-line stor- age capacity in a 5" drive, plus proven Percom reliability. That's what you get in a TFD-200. -■/siiiiwj'i.t.i"i''". .•••';. ■ ti.vh. The DOUBLER™ — This proprietary adapter for the TRS-80* Model I com- puter packs approximately twice the data on a disk track. Depending on the type of drive, you can store up to four times as much data — 350 Kbytes — on one side of a minidiskette as you can store using a Tandy standard Model I computer drive. Easy to install, the DOUBLER merely plugs into the disk controller chip socket of your Expansion Interface. No rewir- ing. No trace cutting. And because the DOUBLER reads, writes and formats either single- or double-density disks, you can continue to run all of your single-density software, then switch to dou- ble-density operation at any convenient time. Included with the PC card adapter is a TRSDOS*- compatible double-density disk operating system, called DBLDOS™, plus a CONVERT utility that converts files and programs from single- to double-density or double- to sing- le-density format. Each DOUBLER also includes an on-card high- performance data separator circuit which ensures reliable disk read operation. The DOUBLER works with standard 35-, 40-, 77- and 80-track drives rated for double-density operation. Note. Opening the Expansion Interface to install the DOUBLER may void Tandy's limited 90-day warranty. Free software patch with drive purchase. This software patch, called PATCH PAK,'" upgrades TRSDOS* for single- density operation with improved 40- and 77-track drives. Quality Percom products are available at authorized dealers. Call toll free 1-800-527-1592 for the address of your nearest dealer or to order directly from Percom. In Canada call 519-824-7041. TM , , _ _ _ , Prices and specifications subject to change without notice. IM trademark of Percom Data Company, Inc. .nark of Tandy Radio Shack Corporation which has no relationship to Percom Data Company. PEFQCM PERCOM DATA COMPANY. INC. 211 N. KIRBY • GARLAND TX • 75042 (214)272-3421 Ciarcia's Circuit Cellar Build a Low-Cost Logic Analyzer Steve Ciarcia POB 582 Glastonbury CT 06033 The Digital Age has spawned a variety of elec- tronic troubleshooting aids, including logic probes, integrated-circuit test clips, multi-trace os- cilloscopes, and logic ana- lyzers. All are useful, up to a point, but it is impor- tant to know when to use a particular test instru- ment and how much you can depend on it. If the logic states of signal lines were the only information needed, a simple voltage measure- ment would suffice in digital troubleshooting. But timing, rather than absolute voltage level, is the more important con- sideration in digital sys- tems. Most digital systems operate by setting discrete logic conditions on bus lines and then strobing that data through the sys- tem at the occurrence of edges of specific clock pulses. A system operates correctly only if all the parallel states are set correctly at a specific instant in time. The system fails if any single logic state is in error at any clock time during program ex- ecution. Photo 1: One frequently used test instrument is a direct-reading state indicator. The sixteen indicators are transistor-driven in- candescent lamps or LEDs (light-emitting diodes). The indicator panel is attached to a "chip-clip" connector so that the logic states on any TTL (transistor-transistor logic) or L5 (low-power Schottky-diode-clamped) TTL dual in-line package can be read while the circuit is energized. The display is most valid for static conditions. The first special digital instrument was the logic probe. A schematic diagram of a typical logic probe is shown in figure 1. This device ac- curately indicates the logic state on LED (light-emitting diode) indicators at any selected point in a circuit. How- ever, it is a static device and will not follow rapid- ly clocked digital logic other than to indicate general activity. Even when the concept is ex- panded to include four- teen or sixteen separate in- dicators on the probe (as shown in photo 1), effec- tive use still depends on stopping the system clock (or slowing it substantial- ly) to examine static logic states. Unfortunately, stopping the clock changes the dynamics of circuit operation and may, in many instances, mask the true cause of problems. More frequently, digi- tal-logic errors are dynamic and occur during clock-state transitions. The errors are often due to timing problems asso- ciated with the propaga- tion of signals through the circuit or with miscuing of multiplexed components. Because the logic state at clock transitions often Copyright © 1981 by Steven A Garcia. All rights reserved. 36 April 1981 © BYTE Publications Inc determines either proper operation or failure, a more suitable test instru- ment would be one that provides the operator with a view of all logic ac- tivity coincident with the transition of the clock. To most people this sounds like a job for a multi-trace oscilloscope with its sweep triggered from the system clock. An oscilloscope can in many instances be of value, but unless it is an expensive storage-tube scope, fast system-clock rates can make viewing difficult. Also, viewing two signals with respect to each other in real time is of little help when the error occurs intermittently and involves more sig- nals than can be viewed simul- taneously. What Is a Logic Analyzer? One solution to the digital- troubleshooting dilemma is called a logic analyzer. This is an instrument that displays a "truth table" of the ac- tivity of the digital circuit being tested under actual operating conditions. After you have selected a key com- bination of input signals, called a trig- ger or sync word, and activated the analyzer, it stores all signal-input logic states for a specific number of system-clock transitions. Depending upon the sophistication of the par- ticular unit, many commercial logic analyzers can accommodate 32 or more inputs and store up to 256 clock cycles before and after the trigger event. A logic analyzer acts like an electronic time machine. In effect, a logic analyzer acts like an electronic time machine. When se- quentially displayed in the order it was acquired, the stored data can be used to form state tables or timing diagrams of the circuit's operation. For example, a logic analyzer might be used to troubleshoot a malfunc- tioning microcomputer I/O (in- put/output) port that keeps receiving consistent but wrong data. You don't know whether the error is caused by the wrong data being sent to the out- put register or by an incorrect address signal strobing the register at the wrong time (try troubleshooting this kind of problem with just an oscilloscope). You can find out by connecting the logic analyzer to the address and data buses of the micro- computer. Set the trigger-word switches to produce a trigger pulse when the ad- dress bus contains the I/O port ad- dress. When the trigger pulse occurs, you can examine the logic states on the data bus with the analyzer to see what value was being loaded into the port register at the occurrence of the trigger pulse, as well as those states following the pulse. It is like having an 8- to 32-channel oscilloscope with the display frozen in time on a specific clock cycle. Commercial logic analyzers are generally stand-alone instruments with integral video-monitor or oscil- loscope displays. They can present stored data in a variety of ways. A data-domain analyzer ordinarily displays logic states as lists of Is and Os. The listings are sequential and in either binary, octal, or hexadecimal format. This display method is par- ticularly helpful when you are debug- ging address-bus problems. In such cases, data is most easily read as INPUT + 5V Number Type IC1 74LS14 IC2 74121 +5V GND 14 7 14 7 Figure 1: A simple logic probe that uses two integrated circuits. When a logic-0 signal voltage is applied to the input, the "logic 0" LED will light. When a logic-1 signal voltage is applied to the input, the "logic 1" LED indicator will light. If the input oscillates be- tween the and 1 states, the "Pulse" LED indicator will also light. April 1981 © BYTE Publications Inc 37 4-digit hexadecimal values. For hardware troubleshooting, a time-domain analyzer is preferred. This unit presents the stored data in timing-diagram format. The result appears like the display of an 8- or 16-channel oscilloscope. The vertical scale has a high-voltage value that represents a logic 1 and a low-voltage value that represents a logic 0. The data signals are plotted with respect to each other and can be displayed as a function of actual time. A third data format is the mapped mode. Essentially, the display screen is divided into an x, y coordinate system, and data points are plotted as dots on the screen. In some units, vec- tors between dots connect successive data points so that it is easier for an ^^L \ \ Si ■• i % ^^^^^^^^ Photo 2: The prototype logic analyzer described in this article. The switches on the left are for setting the trigger (sync) word. Photo 3: Inside the box of photo 2 is the circuit of the analyzer as shown schematically in figure 4. Seventeen integrated circuits are used. operator to trace sequential activity in the device under test. The process of interpreting this kind of display is essentially one of recognizing a "good" pattern and identifying wild vectors. Presumably, a properly operating program will have a repeatable pattern. Any discrepancies will show up as an extra dot or "wild vector." The various types of logic-analyzer display formats are shown in figure 2 on page 40. Regardless of the display format, all logic analyzers share a common internal structure. Generally, they in- corporate the subsystems outlined in the block diagram of figure 3. All logic analyzers have some form of in- put conditioning, trigger-word selec- tion and comparison, memory, and display (LEDs, oscilloscope, or raster- display tube, etc). The combination of capabilities is usually a function of price, which can range from $2500 to $10,000. A Low-Cost Logic Analyzer Obviously, we cannot hope to con- struct a logic analyzer that is equivalent to an $8500 Hewlett- Packard unit. However, we can design a special logic analyzer as a peripheral device of a personal com- puter. By utilizing the display and processing power of the computer, we can greatly enhance the capa- bilities of a relatively simple hard- ware interface. Also, for those readers interested in the concept but not quite ready to grab their soldering irons, I will outline a method that demonstrates how to use your present computer to perform logic-analyzer functions totally in software. First, the hardware approach. Figure 4 is the schematic diagram of a low-cost eight-input logic-analyzer interface that requires only one and a half parallel I/O ports (9 output and 6 input bits) for complete operation. It is easily expandable to 16 or even 32 inputs. All probe inputs and clock signals are conditioned through Schmitt trig- gers to reduce noise and false trigger- ing. When the sync word, set on ex- ternal switches (SWl through SW8), appears on the input lines, the analyzer automatically collects and stores 16 sequential words repre- 38 April 1981 © BYTE Publications Inc senting input status at the instant of either an internal or external clock signal (usually the system clock). It can operate on either edge of the clock pulse and store data at frequen- cies as fast as 5 MHz. The prototype interface is shown in photo 2. Unlike commercial logic analyzers, this unit has no integral CRT (cathode-ray tube) display: it has eight externally controlled LEDs. It depends instead upon the computer to display the list of stored data. After the interface has taken sixteen samples, it sends a Scan Complete signal to the computer. A computer program sets the Read/Write line to the Read mode and sets a 4-bit ad- dress to access the contents of the 16-word scratch-pad memory. As the 4-bit address is incremented, the ap- propriate 8-bit output is placed on the analyzer's data-output lines from the scratch-pad memory and is stored by the computer. In addition, as the computer reads the scratch-pad memory, the contents of each loca- tion are displayed on eight LEDs. If the addresses are changed slowly, or are otherwise physically set, the 16 stored words can be viewed directly without a special display program. Once the data has been acquired by the computer, a format-and-display program lists the values on the com- puter's display in binary, octal, or hexadecimal format, simulating a commercial analyzer display. To gather an additional 16 words, the computer program merely sets the Read/Write line to the Write mode and toggles the Sample Enable line. The BASIC program in listing 1 on page 43 exercises the interface and displays the output shown in listing 2. Inside the Interface The analyzer hardware (shown in photo 3) has an interface consisting of seventeen integrated circuits. Input signals are fed through IC1 and IC2, which are hex Schmitt-trigger in- verters. Photo 4 shows typical test connections. These conditioned out- puts are in turn buffered and gated through to the memory section by IC3, a type-74LS240 8-input bus driver. The output of this driver is compared to eight preset switches through two 74L85 4-bit comparators (IC7 and IC8). (Trigger-word initia- tion is disabled by setting all switches to the logic-1 state. Storage will com- mence on the first clock pulse after Sample Enable.) If the switch settings and data input are equal, a pulse is generated which stores the current in- put data. The first word stored is usually the sync word (assuming that the trigger word and external clock- pulse edge are synchronous). On the trailing edge of the WE (memory-write-enable) pulse, the 4-bit memory-address counter IC9 is incremented. Data will be stored again at the occurrence of the next edge (positive or negative as selected) of the clock pulse. Text continued on page 42 Photo 4: The analyzer is intended for use while a circuit is in dynamic operation. Con- nection to the circuit can be done with the "chip-clip" method shown in photo 1, or by using separate test probes. The latter is more versatile. The circuit shown under test is the Disk-80 expansion interface from last month's Circuit Cellar. Photo 5: When the circuit of figure 5 (on page 42) is attached to the logic analyzer, a data-domain display can be converted to a time-domain display. Essentially nothing more than an eight-channel scope multiplexer, this circuit greatly expands the display potential of the average oscilloscope, as the photo demonstrates. April 1981 © BYTE Publications Inc 39 (2a) (2b) (2c) (2d) Figure 2: The data acquired by a logic analyzer can be displayed in various formats. The different types are: (2a) The ones and zeros logic-state display. In this format, binary words are plotted against clock pulses in a matrix m bits wide by n clock pulses deep. This format is used most often where word flow or data sequence is of prime concern. (2b) Same as 2a except that the data is listed in hexadecimal notation. Hexadecimal listings are most frequently used in logic analyzers specifically designed for microprocessor troubleshooting, where thirty-two to forty inputs are not uncommon. (2c) The timing-diagram display. In the timing format, data words are plotted against time. This format is used most often for hardware troubleshooting to detect in- correct timing between signals. (2d) Vector-display analyzer. In the vector-display format, data words define points on an x, y coordinate system. Usually, the data word is divided in half with a separate D/A converter attached to each segment. One output goes to the display's x input and the other goes to the y input. INTERNAL CLOCK EXTERNAL CLOCK o- o- EIGHT TTL- LEVEL INPUTS o- o- o- o- o- INPUT CONDITIONERS TRIGGER WORD SELECTION SWITCHES DISPLAY I MEMORY COMPUTER WORD COMPARATOR AND TRIGGER CIRCUITRY c SAMPLE AND READ CONTROL Figure 3: Basic block diagram of the simple logic analyzer. In this case, the block labeled "computer" refers to an externally attached personal computer. In commercial units, the computer and display are integral components of the logic analyzer. 40 April 1981 © BYTE Publications Inc Figure 4: Schematic diagram of an eight-input logic analyzer. One and a half parallel I/O ports are required for operation. Note that the 74L85 integrated circuits used here have a different pinout specification from the 74LS85. User connections are on the left; computer connections are on the right. April 1981 © BYTE Publications Inc 41 Number Type + 5V GND IC1 74LS14 14 7 IC2 74LS14 14 7 IC3 74LS240 20 10 IC4 7489 16 8 IC5 7489 16 8 IC6 74LS157 16 8 IC7 74L85 16 8 IC8 74L85 16 8 IC9 74LS93 5 10 IC10 74121 14 7 IC11 NE555 8 1 IC12 74121 14 7 IC13 74LS74 14 7 IC14 74LS02 14 7 IC15 74LS20 14 7 IC16 7416 14 7 IC17 7416 14 7 Table 1: Power connections for in- tegrated circuits of figure 4, on page 41. Text continued from page 39: When sixteen samples have been taken, the 4-bit memory address is binary 1111. IC13 and IC14 detect this condition and set the Scan Com- plete line to a logic 0. This also disables further storage until the in- terface is reset with a Sample Enable pulse to IC2. Reading the contents is simply a matter of setting the Read/Write line to a logic and placing an ap- propriate 4-bit address on the Read Address input lines. When an address is set on these lines, the data-output lines of the analyzer will contain the contents of that memory location. The eight LEDs will also display that value. Creating a Time-Domain Display As previously mentioned, the display format available from this in- terface is generally a listing of Is and 0s. This is quite useful under most circumstances but not as appealing to hardware buffs as a timing-diagram- type output. Even if your computer has graphics capability, writing a program to simulate a multi-trace oscilloscope display requires con- siderable software expertise. The logic-analyzer interface can be converted to a time-domain display with relatively little extra hardware and only a single-line BASIC pro- gram. Figure 5 is the schematic diagram of the additional circuitry. Essentially, it consists of a dual 4-input digital multiplexer and 2-bit D/A (digital-to-analog) converter, which offsets each of the four chan- nels when displayed. In effect, it U5 00 "3- CD CD r~- l~- 03 u-> ""*■ "" "O 7- i- •q- •* ■* 2 2 i^ (^ i 1 —i ■9 *- cm m it cr> co E O O O OOO 3 Figure 5: Eight-channel display multiplexer, which facilitates display of eight TTL in- puts on a standard dual-trace oscilloscope. Its intended use is to convert the data- domain output from the circuit of figure 4 into a time-domain display on an oscilloscope. 42 April 1981 © BYTE Publications lnc allows a dual-trace oscilloscope to display eight channels simulta- neously. Such a display appears in photo 5. Conversion from data-domain to time-domain operation is not as dif- ficult as it might seem. Consider the operation of the analyzer for a mo- ment. Once the 16-word buffer is full, the data can be read out at any rate. If we cycle the read addresses very quickly, the outputs will form a repetitive pattern which can be easily viewed on an oscilloscope. The fast cycling can be accomplished using a 4-bit counter and oscillator source at- tached to the address-input lines or by using a simple program statement like: 100 FOR X = TO 255:OUT 16,X: NEXT X: GOTO 100 Using a dual-trace oscilloscope, you can view two signals, or, with the circuit of figure 5, you can view all eight data channels simulta- neously. Since there is no system clock to contend with and the pattern repeats every sixteen steps, triggering problems are reduced and the display is stationary. All other interface operations remain the same. Adding a Vector-Display Capability If you are determined to hunt "wild vectors," the same technique em- ployed to provide a timing plot lends itself to vector display. Using the same methods to cycle the buffer data on the output lines of the analyzer, substitute D/A converters for the multiplexer in figure 5. Typically, two 4-bit D/A converters are needed. One would be attached to the 4 high- order bits and the other to the 4 low- order bits. One D/A converter is at- tached to the x-axis scope input and the other to the y-axis input. When the buffer is cycled, a unique vector pattern will appear on the screen, describing the 16 data words stored in the analyzer's buffer. (A more infor- mative discussion on this approach to troubleshooting was one of my previous articles, "A Penny Pinching Address State Analyzer," February 1978 BYTE, page 6. It has been reprinted in Ciarcia's Circuit Cellar, Volume I, available from BYTE Books.) Listing 1: A BASIC program that exercises the computer/logic analyzer interface, displaying output through the computer's normal output devices. 100 110 120 130 140 150 160 170 180 190 200 210 220 230 240 250 260 270 280 290 300 310 320 330 340 350 360 370 380 390 400 410 420 430 440 450 460 470 480 490 REM Logic Analyzer Program REM REM data in on port 16, scan complete on bit of port 17 REM read enable and sample enable are bits 6 and 7 REM of port 16 REM read address is bits thru 3 of port 16 REM memory locations 25000 to 25015 is set aside as the data REM buffer PRINT"LOGIC ANALYZER" PRINT:PRINT"Enable New Sample or List Analyzer Buffer"; PRINT" (E or L) INPUT A$ IF A$ ="E" THEN 250 IF A$ ="L" THEN 380 GOTO 190 REM Enable Logic Analyzer and take 16 readings REM pulse sample enable line and set read/write line=0 OUT 16,255:OUT 16,0: OUT 16,255 REM REM test scan complete line IF INP(17) =255 THEN GOTO 300 REM when scan is completed store readings in table FOR S=25000 TO 25015 N=S-25000 REM set read address and store analyzer output OUT 16, N :A=INP(16) :POKE S,A NEXT S GOSUB 3 80 REM Ones and Zeros data-domain display routine PRINT:PRINT D3 D2 Dl DO" :X=PEEK(S) PRINT"D7 D6 D5 D4 FOR S=25000 TO 25015 FOR N=7 TO STEP -1 W=X AND 2"N IF W>0 THEN PRINT"1 IF N=4 THEN PRINT" NEXT N PRINT" SAMPLE #";S-24999 NEXT S GOTO 190 ELSE PRINT"0 READY Listing 2: Sample output produced by the program of listing 1. RUN LOGIC ANALYZER Enable New Sample or List Analyzer Buffer (E or L) ? E D7 D6 D5 D4 D3 D2 Dl DO 1 1 1 SAMPLE # 1 1 1 1 1 1 SAMPLE # 2 1 1 1 1 SAMPLE # 3 1 1 SAMPLE # 4 1 SAMPLE # 5 1 1 1 1 1 1 SAMPLE # 6 1 1 1 1 1 SAMPLE # 7 1 SAMPLE # 8 1 1 1 SAMPLE # 9 1 1 1 1 1 SAMPLE # 10 1 1 1 1 1 SAMPLE # 11 1 1 SAMPLE # 12 1 1 1 1 SAMPLE # 13 1 SAMPLE # 14 1 1 1 1 1 SAMPLE # 15 1 1 1 1 1 SAMPLE # 16 Enable New Sample or List Analyzer Buffer (E or L) ? April 1981 © BYTE Publications Inc 43 c BEGIN J SET STORAGE BUFFER POINTERS AND TRIGGER WORD SET SAMPLE-RATE TIMER VALUE INITIALIZE PIA AND CLEAR STORAGE BUFFER READ PIA PARALLEL INPUT PORT STORE INPUT WORD INCREMENT BUFFER POINTER Q EXIT TO DISPLAY PROGRAM D READ PIA PARALLEL INPUT PORT Figure 6a: Flowchart of a software logic analyzer. Using a Motorola 6820 PIA (Peripheral Interface Adapter), this sequence of operations is all that is required to demonstrate logic-analyzer functions in software. This method is limited in speed of operation by the execution time of the program. v ANALYZER / INPUTS "' Ml B «*■■■■■■■■ ■./.'SUB Hi I NEXI Photo 2: Component side of the main circuit board. Note that component locations are clearly marked, and that the keyboard is an integral part of the printed-circuit board. ■ IS OEM cts GOfeUB «£« «*r a* ak Photo 3: Completed MicroAce with cables. April 1981 © BYTE Publications Inc 47 ao PRINT gOPR CO DISPLAY I ©O PRINT "« MICROftCE COMPUTttft' ©O PfiMENT notice: THAT ft ncu- ©O PRINT "PPOGPOM LINE IS soil HO PRINT "BOTF ITfflBBL 140U ISO iVO PRINT NOT AND THEN TO 4.0 <>> c> HOME HUBOUT ■ ■■■■ NEW 10*0 SAVE RUN CONT HEM IF INK)' PRINT LIST STOP DIM TOW SOTO POKE RAND LET GLEAM l-LS aOSUB MET NEXT OUOTP.TION MftRKa..fflB Photo 5: Layout of the MicroAce keyboard. Note that each BASIC keyword is associated with a specific key. Photo 4: Sample program displayed on a standard color televi- sion set. The current program line is 180, as indicated by the reverse-video cursor. have been given to aid the inexperienced builder. The fastenings provided for attaching the circuit board to the lower half of the case, and for fastening the upper half of the case to the lower, are plastic devices referred to as "rivets." In my opinion, these fasteners are inade- quate. In fact, the rivet at one circuit-board location was useless and kept popping out. To remedy the problem, I used a fine round file to enlarge the holes in the plastic case, and substituted small nuts and screws for the rivets. Plastic washers were used to prevent the circuit board from becoming marred. The keyboard appears to be built up with two layers. The bottom layer consists of the front one-third of the circuit board, while the second layer is laid on top and seems to be secured with some sort of adhesive. This is done by the manufacturer, not the kit-builder. On my unit, this overlay was positioned slightly too far to the left, so that I had to press the right edge of the key, rather than the middle, to get a response to the keyboard entry. In addition, some keys require con- siderably more pressure than others. These factors, plus the fact that no audio or tactile feedback is given to in- dicate a successful keyboard entry, make the keyboard a little frustrating to use. Program Entry The output of the modulator is received on or near channel 35 on a regular television set. I used an RCA 13-inch color set and had no trouble obtaining a good display. With the controls set for normal reception of commercial broadcasts, the display appears as white characters on a gray background. If desired, white letters on an almost black background can be obtained by ad- justing the contrast and brightness controls (see photo 4). On power-up, the display is blank with the exception of a reverse-video "K" at the lower-left corner of the screen. Whenever this reverse K appears, a nonshifted SOFTWARE ENTREPRENEURS WANTED THE 1981 SOFTWARE WRITER'S MARKET lists hundreds of firms who want software from independ- ents. They will buy rights to your software or market and distribute it for you. Includes service bureaus, consult- ing companies, mini/micro manufac- turers, publishers, computer stores, international/national market out- lets — Wang, Apple, HP, ADL, Dig- ital, Atari, CDC, MCAUTO . . . free updates for two months with this ad. Detailed writeups describe how they procure software from independ- ents, what kinds they want, payment rates, how they market, contract de- tails . . . Names, addresses, phone numbers of key industry contacts. The only market report of its kind specifically for independents and small software businesses. Call or write to order! $45.00 per copy VISA/MASTERCHARGE ACCEPTED Include card no. and expiration date with orders. KERN PUBLICATIONS • 190 Duck Hill Road • P. O. Box 1029 • Duxbury, MA 02332 • (617) 934-0445 48 April 1981 © BYTE Publications Inc Circle 30 on inquiry card. Circle 31 on inquiry card. dt H89 Here's the easy way to write your own programs. Heathkit Self-Study Courses give you a complete command of computer language, so you can write the programs that do your specific tasks. Choose from four programming languages. Easy, step-by-step learning You learn at your own pace, performing exercises on your computer and following a clearly written and illustrated text. Tests at the end of each unit assure your understanding before pro- ceeding to the next unit. In most courses your reading is reinforced by cassette tapes, so you see and hear, for more thorough learning. Hands-on programming exercises You learn by doing, not just reading. Special exercises guide you through the steps of designing and writing your own programs for your computer. Upon completion of the courses you'll be able to tailor existing programs to your specific needs, or write your own original programs from scratch. Recommended for college credit Many Heathkit Courses are now recommended for college credit by the American Council on Education. If you can't go back to college, now you can bring college home to you. Free Heathkit Catalog Details and prices on the complete line of Heathkit Self-Study Courses on computer and electronics subjects are in the new, free Heathkit Catalog. Send for yours today or pick one Up I at your nearby Heathkit Electronic Center. FOUR HEATHKIT PROGRAMMING COURSES BASIC": easiest-to-learn, hobbyist's language PASCAL'': sophisticated, easy-to-use language COBOL": the businessman's language ASSEMBLY: very efficient, very precise language Coming soon: FORTRAN" and Microsoft'" BASIC" Write to Heath Co., Dept.334 764, Bunion Harbor, Ml 49022. In Canada, write Heath Co., 1480 Dundas Highway East, Mississauga, Ontario, L4X 2R7. Visit your Heathkit Store Heathkit products ■» " are displayed, sold and serviced at 62 Heathkit Electronic Centers in the U.S. and Canada. See your telephone white pages for locations. In the U.S., Heathkit Electronic Centers are units of Veritechnology Electronics Corporation. Heathkit keyboard entry from the bottom three rows of keys (see photo 5) will result in a BASIC keyword being printed on the screen. Keywords (and thus the use of a reverse K) are BASIC commands which are stored in a single byte of memory but are spelled out on the screen. For a list of these keywords, as well as other BASIC commands and func- tions, see table 1. Nonshifted keyboard entries from the top row are printed as numeric characters for the line numbers (which must be between 1 and 9999, inclusive). As a line number is entered, the reverse K will shift to the right, one space at a time. As long as the reverse K is on the screen, any shifted-key input (other than an editing command) will result in a syntax error. Commands entered without a preceding line number are executed immediately in the "command mode." After entering a line number, press the key corre- sponding to the BASIC keyword with which your pro- gram line is to begin. Every program line must start with one of these keywords. For example, in some forms of BASIC, the LET keyword is optional, and "10 LET A = 5" can be written "10 A = 5". This is not possible with the Micro Ace. Following the entry of a keyword, the reverse K cursor changes to a reverse L, signifying that you are in the letter mode and that keyboard entries will be interpreted as regular alphanumeric or graphics characters. As you type in a program line, the system monitor checks for syntax errors after each character is entered. A line contains a syntax error if, in its present form, the line is incorrect or incomplete. Suppose you wish to enter the following line: SINGLE BOARD TECHNOLOGY mn *2995. Basic system with: 600K bytes • 1.2 megabytes $3995. • 2.4 megabytes $4995. Suggested list price. A Z80A CPU combined with the CP/M® operating system opens new vistas to software availability for eight-bit micros. FORTRAN, COBOL, BASIC, APL, PL/1 and Pascal are available now to accommodate today's scientific, educational, sophisticated small business and personal system users. 4MHzZ80ACPU CP/M 2 operating system 64K 200ns main memory 6K 300ns video memory 8-inch dual floppy drives color video text & graphics sound generator 2-serial ports 2-parallel ports 4-counter/timers ^^ OEM ii ^COLOI ^105Sar ^(203) I ^^k ®CP/M is a registered trademark ot Digital Research, Inc. April 1981 © byte Publications tac Circle 32 on inquiry card. Quantity discounts are available. OEM inquiries are invited. Please contact: COLONIAL DATA SERVICES CORP. J05SanfordSt.,Hamden,Connecticut06514 (203)288-2524 EAST COAST • (415)957-9195 WEST COAST 20 PRINT 'THE FINAL SUM IS "; A The PRINT command is entered by pressing one key (the letter O) because the machine is in its keyword mode at the start of each new line. Immediately following the en- try of the first set of quotation marks, a reverse-video S (for syntax) appears to the right of the reverse-L program cursor. This does not indicate that an error has been made, but rather that the line is incomplete. As the literal Keyword Commands Keyboard Comments Abbreviation CLEAR Set all variables to zero CLS Clear the screen CONT Continue DIM Dimension (one-dimensional arrays) FOR GOSUB GOTO IF INPUT LET LIST LOAD Cassette input NEW NEXT POKE PRINT RAND Randomize REM Remark RET Return RUN SAVE Cassette output STOP String Functions Function Comments CHR$(/V) Return character or keyword string corre- sponding to decimal code N. CODE(S) Return decimal code number of first character in string S STR$(/) Convert the integer / into its corresponding string representation. TL$(S) Delete the first character from string S. Other Functions Function Comments ABS(N) Return absolute value of N. PEEK(/V) Return decimal value stored in memory at address N. USR(/V) Start machine-language routine at address N. Return a random number between 1 and N RND(W) if N is positive. Logical Functions Function Comments AND Check to see if two or more conditions are met simultaneously. OR Check to see whether any one of two or more conditions is met. NOT The opposite of a stated condition is tested. (These logical functions have additional uses which cannot be detailed here.) Arithmetic Operations + Addition — Subtraction * Multiplication / Division * * Exponentiation (2**3 = 2*2*2 = 8) Table 1: Commands and functions available in MicroAce in- teger BASIC, with comments at selected points. The manual supplied with the kit provides a more detailed explanation. 50 Circle 33 on inquiry card. Solution \s6 J lii-shun\ n[ME,f r.MF,£r.L solution-] la: An answer to a problem. At last there's a microcomputer designed to solve your business' problems, not create new ones. In delivery for close to three years, the MicroDaSys Millie™ is a proven hardware clesign that now comes with the fantastic SoftwareHows™ DBI Accounting Solutionware™you've seen advertised -- a $2500 dollar value alone! This is one computer that's complete when you buy it, right down to the best applications software available. There are no "required options". And we've got all the best features: Z-80, 64K, CP/M 1 , dual double density 8" floppies for 1MB on line storage, 82x24 CRT with special features, IBM format keyboard with numeric pad, NEC 55cps letter quality printer, S-100 bus. Also, Millie is supported by a nationwide rep network and one of the best service contracts in the business. And Millie is price competitive with much smaller computers. Why settle for less than the best? Call or write today for flyers and manuals. You'll be glad you did. iCfODaSyS, IriC. 2811 Wilshire Blvd., Santa Monica, CA 9040: (213)829-6781 TWX: 910-321-2378 n.g.TM, Digital R«B*atafi ■■■H SYSTEM VARIABLES (40) (eg: POINTERS) PROGRAM VARIABLES END OF VARIABLES (2) WORKING SPACE DISPLAY FILE SPARE STACK 16384 AVAILABLE ON KEYBOARD AVAILABLE USING AND USING CHRS CHR$ ONLY Figure 1: Map of the programmable memory in the MicroAce computer. Fixed boundary addresses are given in decimal; the other boundaries are variable. Numbers in parentheses give the size of a fixed block in decimal bytes. string is entered, the reverse LS moves to the right as a double cursor. When the second set of quotation marks is entered, the reverse S disappears because the line now has the correct syntax. Consider a second example. You wish to enter the line: 125 LET 1 = 1 + 1 but inadvertently type: 125 LET 1 + 1 = 1 This line would not be accepted because it contains a syn- tax error. The reverse S cursor would be located directly after the + symbol. Notice that in this case the reverse S does not follow the reverse L cursor, but remains at the point where the error occurred. In the case of multiple errors, the reverse S will always be located at the first error contained in the line. When this error is corrected, the reverse S moves to the second error, and so on. As indicated above, no line containing a syntax error will be accepted into a program. This guarantees that every line in your final program is complete and free of syntax errors. It does not, of course, prevent errors of logic. When a line is complete and correct, it can be entered into a program by pressing the NEWLINE key — the MicroAce equivalent of a RETURN key. As a line is entered into a program it is placed into memory in two places. First, it is placed into the program storage area, which begins at decimal address 16424. (See figure 1 for a simplified map of the programmable memory.) It is also relocated in the display-file section of memory so that it appears on the upper portion of the screen. E H E a H H Figure 2: Graphics symbols available with the MicroAce. Note that the first ten symbols are addressable from the keyboard, while the second ten are their reverse-video images, available only through the use of the CHR$ function in BASIC. Recall that on power-up the reverse K was at the lower left and that line entry was done at the bottom of the screen. As new lines are entered they appear in numerical order. The most recently entered line is identified by a line cursor (a reverse video > ). A line entered with a number between those of two previously entered lines is placed in the appropriate posi- tion on the display, and the line cursor is moved to its location. When the screen is full, the addition of new lines causes the program listing to scroll up, always leav- ing the most recently entered portion on the display. This method of using programmable memory for both program storage and display storage leads to problems. In some systems, the video-display memory is dedicated, meaning that an advertised 1 K bytes of programmable 52 April 1981 © BYTE Publications Inc Circle 34 on inquiry card. Most small system users think all micro- computers are created equal. And they're ight. If you want performance, convenience, styling, high technology and reliability (and vho doesn't?) your micro usually has a price ag that looks more like a mini. It seems big lerformance always means big bucks. But rat so with the SuperBrain! Standard SuperBrain features include: twin double-density 5 1 / 4 " drives which boast nearly 350,000 bytes of disk storage - expandable :o 10 megabytes. A full 64K of dynamic RAM. A CP/M* Disk Operating System to nsure compatibility to literally hundreds of application packages presently available. And, a 12" non-glare, 24 line by 80 column screen. You'll also get a full ASCII keyboard with an 18 key numeric pad and individual cursor control keys. Twin RS232C serial ports for fast and easy connection to a modem or printer. Dual Z80 processors which operate at 4 MHZ to insure lightning-fast program execution. And the list goes on! Feature after feature after feature. Better yet, the SuperBrain boasts modular design to make servicing a snap. A common screwdriver is about the only service tool you'll ever need. And with the money you'll save on purchasing and maintaining the SuperBrain, you could almost buy another one. For under $3,500, it is truly one of the most remarkable microcomputers available anywhere. Whether your application is small business, scientific, educational or just word processing, the SuperBrain is certainly an exciting solution to the small computer problem. And since you can easily expand it, you'll probably never outgrow it. Call or write us today for a complimentary copy of our "SuperBrain Buyer's Guide." We'll show you how you can get big system per- formance without having to spend big bucks. r= INTE3TEC Cdata s systems. 2300 Broad River Rd. Columbia, SC 29210 (803) 798-9100 TWX: 810-666-2115 ■flegtsitred HWemark ot DtQiQI Research mc TWI n. intrtk: data sysems I sup^brain- •■ " i i i i t, L S memory are used for program storage only, and that ad- ditional memory is supplied for storing video data. With the MicroAce, the programmable memory avail- able to the user must perform both tasks. Thus, as pro- gram length increases, the area for displaying the pro- gram listing begins to shrink as less and less memory is available for display storage. As a result, the program line-entry "window" moves up from its bottom position on the screen. The advantage of this system is that when your line-entry window is near the top of the screen, you know you are close to filling the available program memory. The disadvantage is that shorter and shorter segments of a program can be listed at any one time. As you will see later, this dual use of memory causes similar difficulties when running a program. Another feature of the MicroAce is that there is no limit (other than available memory) to the length of a program line. Thus, a large section of text can be printed using a single PRINT command. This can save time and memory if properly used. A disadvantage of the system is that multiple statements on a single line are not allowed. For example: 230 LET A = 5: LET B = 9 would have to be written as: 230 LET A =5 235 LET B =9 In another example: Leverage User Environment Termed 'Unusually Friendly' Advanced Human Engineering, Superior Documentation, Detailed Tutorials and Ongoing Support Are Cited Early reports from users of Leverage, the microcomputer-based infor- mation management system recently introduced by Urban Software Cor- poration, reveal a level of satisfaction rarely found among users of micro- computer applications programs. Several factors have been cited to ex- plain this highly favorable response, including: • State of the art human engineering. Features like an extensive on-line manual directly accessible by the program, graphic menu selection and automatically programmed menus allow unparallelled ease of use. • Several easy to follow tutorials demonstrate the capabilities of the system and provide an ideal vehicle for mastering its operation. • Clear, complete documentation includes a glossary, an index and numerous tables and figures. • Urban Software is firmly committed to the ongoing support of Leverage. Many enhancements are planned, and a monthly newsletter will provide application notes, manual updates, bug reports and new prod- uct announcements. Leverage Program $185 Manual Alone $ 15 (Credited to subsequent program purchase) Leverage Newsletter ... $ 10/year (First year included with purchase) For complete details on Leverage, call or write for a brochure. Leverage is a trademark of Urban Software Corporation. Urban Software Corporation 19 West 34th Street* New York, NY 10001 • (212)947-3811 200 INPUT A,B,C would have to be written as: 200 INPUT A 205 INPUT B 210 INPUT C Program Editing As indicated earlier, new lines can be inserted anywhere in a program by entering them in the normal fashion. Entire lines can be deleted by entering the line number and pressing NEWLINE. If the line that is cur- rently displayed needs editing, the following procedure is used: the up and down arrows (shifted 7 and shifted 6, respectively) are used to locate the line cursor at the pro- per line; then EDIT (shifted NEWLINE) is pressed to copy the desired line in the program-entry window at the bot- tom of the screen. The left and right arrows (shifted 5 and shifted 8, respectively) are used to position the program cursor within the line. Deletions are made by placing the pro- gram cursor to the right of the desired character or keyword and pressing RUBOUT (shifted numeral 0). Insertions are made by merely typing in the correct character or keyword. The portion of the line to the right of the insertion shifts to the right to accommodate the in- serted text. You cannot over-type incorrect text; it must be deleted using the RUBOUT command. A line that is not presently on display can be edited in one of two ways. The up or down arrows can be used to scroll the program listing down or up on the display until the desired line appears, or the LIST command can be used instead. Normally, a LIST command will list the program start- ing with the line preceding the requested line. If, for ex- ample, the lines are numbered by tens, then a LIST 120 will result in a listing that begins with line 110 and con- tinues as far as space and display memory permit. In either case, once the desired line is displayed on the screen, it can be edited as described above. MicroAce has one disconcerting feature that affects the entering and editing of programs. The microprocessor performs only one function or task at a time. Thus, it either handles keyboard input or controls the video display, and as a result, every key closure during pro- gram entry and editing causes the display to roll. This makes it difficult to use the editing arrows, as it is hard to follow a moving cursor on a rolling display. Running a Program A program is executed by entering the RUN keyword command followed by NEWLINE. During program ex- ecution, the display remains blank until a STOP or IN- PUT command is executed, a BREAK or an error occurs, or the program completes its run. At that point, the microprocessor is free to devote its attention to the video display. This means that a PRINT command in a pro- gram merely loads the data into the display memory for future use. It will not appear on the display until active execution of the program ceases. For this reason, animated graphics are not possible. As mentioned earlier, there are some problems related to running programs, because the available program- 54 April 1981 © BYTE Publications toe Circle 35 on inquiry card. Circle 36 on inquiry card. Sweeten Your Apple II* with the ES/F Mass Storage System THESE FACTS SPEAK FOR THEMSELVES! A Actual Size Actual Thickness T CASSETTE ES/F MINI-DISK SPEED (10K Load) 60 sec 5.5 sec 8.4 sec CAPACITY (K bytes) 100 (C-IO) 125 (75') 103 APPLE DOS RELIABILITY (Designed for digital data?) NO YES YES SYSTEM COST (First unit W/l/F) $60 $300 $600 SECOND UNIT N/A $150 $500 MEDIA COSTS $3.00 $3.00 $5.00 OPERATING SYSTEM NONE APPLE SOS APPLE DOS Let's face it. Cassette players were not designed to store digital data and pro- grams. That's why we designed a digital storage system using a continuous tape loop: the Exatron Stringy/ Floppy (ES/F) and the Wafer. There's no ex- pensive interface to buy -the ES/F comes ready to sweeten your Apple II*. Once your Apple II* is sweetened with our ES/F . . . you won't find a juicier deal. We're so sure, that we offer an unconditional 30-day money-back guarantee and a one-year limited war- ranty. Over 5,000 owners have met the wafer . . . why don't you? EXATRON S STRINGY/FLOPPY . . SPEED, CAPACITY AND RELIABILITY FOR ONLY $299.50 CALL OUR HOTLINE . . . (800)-538-8559 IN CALIFORNIA. CALL (408)-737-7111 'Apple II is a registered trademark of Apple Computer. exatron 181 Commercial Street Sunnyvale. CA 94086 SUPERBRAIN ANDCOMPUSTAR USERS'GROUP Your users' group is here at last! We are Super* Star International, an independent, world-wide users' group for Intertec Data Systems' SUPERBRAIN™ and COMPUSTAR™ computers. Our monthly magazine SUPER *STAR will fulfill all your computing desires. When you join our group, you will enjoy the latest: technical information, tips for beginners, special business uses, equipment reviews, the Intertec story — the people, ideas, and machines behind your computer. In every issue you'll get a free program, industry news, and software reviews. Plus, we want your programs for our Software Supermarket, where all members can buy programs at affordable prices. We will investigate all the accessories you have always wanted, test them, and offer them for sale at reduced prices. With our group buying power we'll give you discounts on commercial software. And that's not all. We'll find group rates for car rentals, hotels, gifts, and more. Super* Star International, with savings, service, and efficiency — we're here to win your heart. Yearly membership fee is $50.00 U.S., $58.00 Canada, $74.00 Europe and So. America, $81.00 Australia. Your fee may be tax deductible; consult your accountant. Dealers are invited to contact us concerning a special dealer program. Software houses, we are interested in your programs! Send checks with your name and address, made out to: SUPER *STAR INTERNATIONAL CORPORATION 3722 Chestnut Place Denver, Colorado 80216 (303) 623-7973 Not affiliated with Intertec Data Systems. 'Superbrain and Compustar are the trademarks of Intertec Data Systems. mable memory is used for both program and display storage. Program memory is given priority, so if, for ex- ample, a PRINT command giving some instructions con- tains more characters than the available display memory can accommodate, the displayed message terminates at the point where display memory was filled, program ex- ecution stops, and an error message appears at the lower- left portion of the screen. This clearly limits the amount of displayable text that can be included in a program. In the worst possible situa- tion, where the entire screen is filled, 768 bytes of memory (32 X 24 =768) would be required for the display alone. Only 256 bytes remain in which to store system pointers, program lines, variables, and so on. Furthermore, the display will not scroll during pro- gram execution. If a PRINT command results in a line of text beyond line 24, program execution ceases and a dif- ferent error message is displayed. The PRINT and CLS (clear screen) commands must be used judiciously in order to avoid printing too many lines, on the one hand, and clearing text before it can be read, on the other. MicroAce Integer BASIC Integer BASIC is limited in its computational capa- bilities. All numbers used in computation must be in- tegers in the range —32768 to 32767, inclusive. Results of arithmetic operations are truncated (ie: all fractions are dropped). Thus, 99 divided by 100 would come out 0, because the division normally yields a quotient of 0.99. But integer BASIC drops all fractions, leaving 0. Only the fundamental operations of addition, subtrac- tion, multiplication, division, and exponentiation (using positive integral exponents) are implemented. This is true not only for MicroAce integer BASIC, but for any form of integer BASIC. The purpose of integer BASIC is to provide the user with a high-level programming language in as little memory as possible. This should be kept in mind when evaluating the capabilities of an integer BASIC. While the features of MicroAce BASIC are given in table 1, a few points should be emphasized. Note that string manipulation, a feature not always included in in- teger BASIC, is possible. Also, a USR function is pro- vided which allows the user to run machine-language programs. I have not yet experimented with this feature, but should point out that the manual does not teach you any machine-language programming. It merely suggests that you write a monitor in BASIC to enter machine- language programs, and use the USR function to run them. The use of keywords was discussed earlier. This greatly simplifies program entry because entire commands are entered with a single keystroke. Memory is conserved because each keyword occupies only a single byte of memory. Any keyword command can appear in an ex- ecutable program line including LIST, LOAD, SAVE, RUN, and NEW. You have to be very careful with some of these com- mands. Program execution terminates following a LIST. The NEW command executed in a program, or in com- mand mode (executed directly from the keyboard), would wipe out everything in memory, including the pro- gram itself. The LOAD and SAVE commands would be of little value in a program since the cassette recorder 56 April 1981 © BYTE Publications Inc Circle 37 on inquiry card. Circle 38 on inquiry card. THE SOLUTION STORE Makes The Difference! 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B4 Northridge, CA 91324 : April Special*: NEW Leedex Monitors Leedex 100G • Green phosphor for easy viewing • Hi-resolution Cat No. 2999 $169 00 13" Color Monitor • Hi-Resolution • Full color • Low cost Cat No. 3000 $399 00 Don't Miss Out . . . ... on the other terrific buys in the Hobby- world catalogue. Page after page of computer products for the Atari, Apple, TRS-80 and others. Our catalogue is FREE, so write or phone for your copy NOW! Toll Free: (800) 423-5387 Local & Outside USA: (213) 886-9200 Open Monday thru Friday: 10am-6pm Saturday: 9am-5pm We're changing our name to keep pace with the times! Look for our new name, HW Electronics, in our ads beginning In June, 1981. would have to be turned on at just the right moment in order to complete the command execution. The MicroAce BASIC provides an error message whenever program execution ceases. The number of dif- ferent messages is limited, but remember that all program lines must have correct syntax before they are accepted into a program. The error messages are given in the for- mat c:nnn where c is an error code, and, in most cases, nnn is the last program line executed. Here are some ex- amples: 0:400 This could mean one of two things. Either the program has come to a successful end at line 400, or a BREAK was executed and line 400 would have been the next line executed in the program. 5:40 This indicates that a PRINT command in line 40 attempted to print beyond the twenty-fourth line on the display, which, as noted above, is not possible. 4:40 This might indicate that a LET command was used when there was no more memory available for variables storage. (The error code indicates there is not enough memory to perform the given line.) The system of error messages, together with the syntax checking feature, make program debugging quite easy. This is definitely one of the strong points of MicroAce BASIC. One negative aspect of the MicroAce BASIC is the in- ability to halt program execution at an INPUT command. When executing an INPUT command, the BREAK key is, in effect, ignored. This is not that unusual as other com- puters exhibit the same property. However, any key en- try, including NEWLINE (and that is a bit unusual), that is not a valid response to the INPUT command results in the appearance of the reverse-video S syntax error cur- sor, which means that the response will not be accepted. It must be deleted using the RUBOUT command, and a correct response must be entered before program execu- tion resumes. I entered a relatively simple game program which in- volved locating a submarine within a three-dimensional region. The player is allowed seven trials, and must input three coordinates during each trial. Thus, a maximum of twenty-one INPUT commands will be executed. Unless a STOP command or an escape routine is included in the program (or you disconnect the power), there is no ob- vious way to terminate execution of the program until all twenty-one INPUTs are responded to properly. This could make debugging of highly interactive programs a time-consuming process. By the way, even though this program was quite short, the instructions for playing the game could not be displayed without overflowing the available display memory. Consequently, they had to be omitted from the program. Graphics There are twenty graphics symbols available, as shown in figure 2. Note that only ten are available from the keyboard. The remaining ten are reverse- video graphics available by using the CHR$ function. In fact, any alphanumeric character, graphics symbol, or keyword string can be printed using the CHR$ func- 58 April 1981 © BYTE Publications Inc Circle 39 on inquiry card. Circle 40 on inquiry card. m — TV ] npan pan pnnni pnan ppi nmnni nnnnn pnnri pnnn p gnni pinna jbbm em mm mm ww i NEVER UNDERSOLD! That's right, if you can find a lower price in this magazine for any of the Items lilted In this ad, we will reduce our price below our competitor's price. See each box below to determine how much EXTRA we will cut off of THEIR price if we're not lowest. Please consider the competitor's shipping charges, OUR SHIPPING IS FREE)* s DOT ffff ll/llll/ll/lll/HA\lllll\\ll//ll71I7WI^ ii/niMiPii m iiillM ras Mm Aiii/»[iuifnnnuiwiiinuMinM|P frft FLOPPY DISKETTES & SUPPLIES If YOU CAN FIND A LOWER PRICE IN THIS MAGAZINE ON ANY OF THESE ITEMS, DEDUCT $.50 FROM OUR COMPETITOR'S PRICE, THAT'S OUR PRICEI Call For Quantity Discounts Verbatim Dlfk.tl.i (box of 10) 5'/." MD525-01 soft.lOor 16 $26.50 5%" MD577-01 quad soft. 10 or 16 . .$33.00 8" FD34-1000soft $30.00 8" FD32-1000hard $30.00 8" FD34B000 double density soft . . . .$44.00 8" FD32-8OO0 double density hard . . $44.00 Prlntwheels (specify style] Qume or Diablo $6.50 Lab*ll 3'/. "xlS/16" (5000 labels) $18.75 Other sizes and quantities CALL Ribbons Diablo Hy Type I $4.95 Diablo Hy Type II $5.25 Qume Sprint $3.50 Centronics Zip Pack $3.95 MANY OTHERS CALL ffff PRINTERS IF YOU CAN FIND A LOWER PRICE IN THIS mAGAZINE ON ANY OF THESE PRINTERS, DEDUCT $10 FROM OUR COM- PETITOR'S PRICE, THAT'S OUR PRICEI Epson MX 80 CALL Okidata Microline-80 $550 Okidata Microline-82 CALL Okidata Microline-83 CALL IDS Paper Tiger 445G $775 IDS Paper Tiger 460G $1193 Anadex DP-8000 (AP) CALL Anadex DP-9500 $1395 Centronics 737 $799 NEC W/Sellum Bi.Dir. Board $2595 Vista 25 CPS $1595 Qume CALL Diablo CALL Escon Interface $545 Call For Other Printers SOFTWARE, MODEMS & TRS-80 HARDWARE IF YOU CAN FIND A LOWER PRICE IN THIS MAGAZINE ON ANY OF THESE ITEMS, DEDUCT 3% FROM OUR COMPETITOR'S PRICE, THAT'S OUR PRICEI SOFTWARE Microsoft Basic Compiler $345 Basic-80 $319 Fortran-80 $399 Cobol-80 $599 Macro-80 $144 Pickles and Trout CP/M CALL Grahm Dorian CALL Peach Tree CALL Magic Wand CALL Supersoft CALL PCD Pascal $350 Visicalc $124 Space Invaders $23 Adventure $26 Head cleaning kit $26 MODEMS UDS103CP $175 D-CAT $155 CAT $145 TRS-80 HARDWARE Micropolis 77 track SUPER SALE »399 Lobo Drives CALL Matchless Drives CALL m !■= L3_ 13= 4636 Park Granada Calabasas, Ca. 91302 fllpis Eijta Sicrssa £H3 For phone c (213) 8 & rders CALL: B3-8594 LX1 IF YOU CAN FIND A LOWER PRICE IN THIS MAGAZINE ON ANY OF THE ITEMS LISTED BELOW, DEDUCT 5% FROM OUR COMPETITOR'S PRICE, THAT'S OUR PRICEI (BUT IF YOU DON'T SEE IT, CALL FOR A PRICE— WE WILL BEAT EVERYBODYI) S-1 00 HARDWARE APPLE HARDWARE CALIFORNIA COMPUTER SYSTEMS: 16K Static RAM (Model 201 6C) $349 32K Static RAM (Model 2032A) $599 64K Dynamic RAM (Model 2032A) $599 16K Static RAM (Model 2065A) $299 Main Frame (Model 2200A) $339 Floppy Disk Controller (Model 2422A) $339 4 Port Serial I/O (Model 2710) $CALL 2S + 2P I/O (Model 2718) CALL Z-80 CPU (Model 2810) $249 Godbout Econoram CALL SD Systems Versa Floppy $279 Expando RAM $CALL Microsoft Z-80 Softcard $259 SSMAIO $165 SYMTEC Apple Light Pen $219 CALIFORNIA COMPUTER SYSTEMS: Parallel Interface (Model 7720A) $112 Asynchronous Serial Interface (Model 7710A) $149 Programmable Timer (Model 7440A) $149 12K ROM/PROM Module (Model 71 14A) . . . .$75 Arithmetic Processor (Model 781 1 A) $374 Synchronous Serial Interface (Model 7712A) $149 GPIB Interface (Model 7490A) $281 3% Didgit BCD A/D Converter $1 40 Centronics Printer Interface (Model 7728) . . $99 MOUNTAIN HARDWARE: Super Talker $270 ROMWRITER $157 INTROL/X-10 $180 ROMPLUS+ $162 MUSICSYSTEM $499 Apple Clock $252 Lobo Drive $CALL Videx 80X24 $345 Andromeda $1 89 L3=) i_J=l *FREE shipping on all orders over $20. Visa ond Master Card accepted. All never undersold offers good as supply lasts. Please add 2.00 for all COD orders. Please call for items not listed. We glad- ly answer any questions on all of our hardware, software, and supply needs. Quanitity discounts available. School purchase orders accepted. Please remember to figure competitors shipping and handling charges when arriving at never undersold price. tion. Most characters can be printed in reverse-video as well. The BASIC manual provides a complete list of all available characters and strings, along with their decimal codes. The code is unique to MicroAce and thus not com- patible with standard computer codes. Since each character position on the 24 by 32 display is divided into four parts by the graphics symbols, a resolu- tion of 48 by 64 dots is possible. Remember though, that an extensive graphics display greatly limits the amount of memory available for program storage. Cassette Input and Output I had to try two tape recorders before I could suc- cessfully load a program from tape. The first recorder I tried lacked a tone control and could not load a program, regardless of the volume setting. The second recorder had a tone control and loaded properly with the control set at maximum treble. The proper volume level seems to vary from tape to tape, even when they are made by the same company. Before saving a program, the program name is recorded on the tape by voice. A cable is attached between the microphone output of the computer and the microphone input of the recorder. The recorder is placed in its record mode and the SAVE command is entered followed by NEWLINE. The televi- sion screen goes blank for about five seconds, followed by a jumpy display of horizontal white lines. This in- dicates that the data is being output to the recorder. When the display returns to normal, the save is complete. Loading a program involves a similar series of steps. In OVER 8 MBytes OF SOFTWARE AT $8 PER DISKETTE FULL The exchange library of The CP/M® Users Group has nearly 50 volumes of software available. Everything from editors, assemblers, languages, games, tools and more-and almost everything in full source code. Send $6** for full library catalog. THE CP/M USERS GROUP 1651 Third Avenue, New York, NY 10028. "Domestic price. Inquire for overseas price. "The complete catalog of CPMUG is available for $6 prepaid to the U.S., Canada and Mexico. $11 prepaid to all other countries. ® CP/M is a registered trademark of Digital Research. The CP/M Users Group is not affiliated with Digital Research. this case, however, you cannot be certain that the pro- gram is being input until the screen resumes its normal display, giving a listing of the tail end of the successfully loaded program. If, after a reasonable interval of time, the display does not return to normal, the BREAK key may be used to reset the computer. Occasionally, you may have to disconnect the power momentarily to recover from an unsuccessful load. Once the proper volume setting is found, however, loading can be done quite reliably. The Teach-Yourself Manual The manual supplied with the MicroAce, entitled The Teach-Yourself BASIC Manual, is shown in photo 1. The title may be slightly misleading. It brings to mind a tutorial text complete with exercises for the reader, but it is not that kind of text. It merely introduces the BASIC commands, one at a time, illustrating their proper use and perhaps some typical applications. At the same time, the processes of program entry, pro- gram editing, and program execution are taught. Token coverage is given to the art of programming, but in all fairness it might be unreasonable to expect a more de- tailed explanation. As an introduction to the use and syn- tax of fundamental BASIC commands, the manual is quite adequate. While typing errors (or misprints) are inevitable, I do think that special care should be given to printing sample programs. One program in the manual has two lines which read "GO TO 7000" when the program contains no line numbered 7000. Those two lines should have read "GO TO 1000". As written, the sample program would not run successfully. Other Considerations I believe that any product's value is partially deter- mined by the manufacturer's willingness to respond to the consumer's request for aid or assistance. Nine weeks prior to the writing of this review, I sent a letter to MicroAce requesting answers to specific questions related to the MicroAce and to future plans for upgrading and expansion. That letter was never answered. This, to me, indicates a lack of interest in serving the customer. At the same time that the letter was sent to MicroAce, a similar letter was sent to Sinclair Research Limited, the company that markets the Sinclair ZX80. (The MicroAce is essentially a kit version of Sinclair's machine and is manufactured under a license from Sinclair Research Limited.) Sinclair's response to my letter left many questions unanswered (especially in regard to future plans), but they did say that the MicroAce operates in the same man- ner as the ZX80. Consequently, the comments made in this review concerning the operation of the MicroAce would apply to the Sinclair ZX80 as well. I was also told by Sinclair that while the unit operates like the ZX80, it is not identical to it, and that peripherals marketed for the ZX80 might not work with the Micro- Ace. They did not elaborate, and, as noted above, Micro- Ace had no comment at all. Conclusions The MicroAce kit is a very inexpensive introduction to the world of microcomputers. Kit construction is easy 60 April 1981 © BYTE Publications Ire Circle 41 on inquiry card. Suddenly Radio Shack's New TRS-80 Color Computer is Even Better! New Extended Color BASIC. Here's an advanced TRS-80 Color Computer that includes a 16K ROM Extended BASIC with advanced graphics, eight brilliant colors, and sound, for an unprecedented low price! You can draw fine lines, circles, rectangles, boxes and more with easy-to-use one-line com- mands. Four graphic modes with two color sets allow up to 49, 152 programmable screen points (pixels). There are 255 separate tones for music or sound effects. All this on a 16K RAM machine (including video memory) loaded with the dynamic features a serious programmer demands. You get a 32x16 screen, multi-character variable names (two signifi- cant), editing, tracing, user-definable keys, 255-character string arrays, floating point 9-digit accuracy, and even machine language routines. Priced at Only $599, the TRS-80 Extended Color BASIC Computer is useful, entertaining and educational. Yet using it can be as simple as plugging in one of Radio Shack's instant-loading Program Paks. Come in and see what's already available. The computer attaches to your TV, or our own $399 TRS-80 Color Video Receiver. For just $24.95, you can add a pair of joysticks which add flexibility to games and video displays. A built-in serial interface lets you attach a printer or a modem. A tutorial Color BASIC instruction manual is included, of course. More Good News. Extended Color BASIC is also available as an upgrade kit ($99) for the 4K Color Computer (16K RAM required — $119). There's a modest installation charge for each kit. New TRS-80 VIDEOTEX Software (with the modem shown below) offers Color Computer owners quick, affordable access to many kinds of information and data services. For example, our exclusive agreement with CompuServe i? Information Service gets you local, national and international news, weather and sports from 1 1 area newspapers and the Associated Press News Service; information on over 32,000 stocks and bonds; an educational reference service; enter- tainment news and reviews; nationwide Electronic Mail with other users; and much more! You'll also access Dow Jones Information Services for Wall Street news, stock quotes and more. Only $29.95 Buys You VIDEOTEX Software including a free hour on both CompuServe and Dow Jones, plus operator's manuals. Come see the new TRS-80 Color Computer, its programs and accessories, at one of our 6000 outlets today! enough that beginners can tackle the project with con- fidence, assuming that they learn correct soldering techniques. Proper soldering is so crucial to success that I would advise those with no experience to purchase Heathkit's soldering course. This course is part of Heathkit's con- tinuing education program, and costs $15.95 plus ship- ping. While I have not seen this particular course, I am sure, based on my experience with their other products, that it would be worthwhile. For further information, write to Heath Company, Benton Harbor MI 49022. MicroAce BASIC contains several nice features. The use of keyword commands simplifies program entry and reduces the amount of memory required for program storage. Because line syntax is checked before the line is entered into a program, fewer programming errors can occur. This feature is especially useful for those just learning how to use BASIC. The machine's compact size and light weight make storage and transportation very easy. The unit is simple to attach to a home television set, and the cassette input and output operations are reliable, once the proper set- tings are found. The largest drawback is the severely limited amount of programmable memory. This disadvantage is most ap- parent when you try to write any but the shortest pro- grams utilizing a significant amount of video display. I would strongly encourage any prospective buyer to pur- chase the 2 K-byte version of the MicroAce. Another drawback is that the screen is blank during active pro- gram execution. This limits the types of possible graphic displays, and can be somewhat annoying. If you recognize the limitations of the machine and don't expect too much, then I think you can buy the MicroAce kit with confidence. It is most appropriate for someone who wants an inexpensive unit as a teaching tool in order to learn the fundamentals of BASIC pro- gramming. It might also appeal to hobbyists who want to "tinker around" with microcomputers but don't want to risk their more expensive equipment. ■ OKI DATA COMPUTERS Microline 80 Microline 82 Microline 83 $499 $699 $949 |^ PAPER TIGERS] ./%._ ■K i HBB 445G S740 460G uno M AMADExl IU0RTH5TAR Burned and rested - backed by fosr worronry service. Find out why out prices, availability and service make us the #1 soutce fot rhe #1 5-100 system. HRZ-II 64K DD $2595 HRZ-II 64K Quod $2995 HRZ-II 32K DD $2339 HRZ-II 32K Quod $2689 ONYX The 2-6000 arrives with Winchester storage, tape backup, proven multi-user software, Pascal, fortran and more. C6002 Sl4,flfl5 ATARI Duy a 16K Atari 600 for $775 and get 1 odd'l. 16 Ic for $69 and/or 410-659, Star R. $09. Joysticks &14, 610 Drive S449. ZENITH The all-in-one compurer that's backed by your local Zenllh/Hearh service center Z89 w/48K 2 SIOs $2149 IQ120 $729 IQ135 $799 IQ140 $1159, TELEVIDEO 912C $729 920C $759 950 $949 We participate in orbirrotion | ^^H ■ TERMINALS Jr. lot business and customers \ ! / jm^L thtough rhe Dertet Dusiness Vm^-**' Bureau of Maricopa County. ~~"~TwK. -TV Scottsdale Systems 6730 E. McDowell Rood #1 00, Scottsdale, Arizona 85257 ^^^^ Open 8-5 Mon.-Fri. _ — „ DP-9000 $1199 I >,OUZ/ 7H rJOJU I Hozeltine 1500 $859 DP-llo? $1299 I I Ex P orf P ric e s slightly higher: TWX 910-950-0082 (IMEC SCOT) I PkTcf^om $599 Zenith Z-19 $789 A W ORDERING TI810Bosic $1489 ru„Ki„ A-»n toooo ~^W Moil-Order Only T i RO c n,-, ■>„.,, c-nAn Diablo 630 $2299 n o/3 ku uastc »i lou Epson ^.gQ Co|| i 2% cash discounr included / charge cords odd 2%. Prices subject to C. Itoh S'orwnter JfiZ MPI fl8G * 669 I change, product subject to availability. Arizona residents add 5%. CenKS 73 7 :s I:::: $779 ^{o wASS* $26 C 9°9 I ^° D - S f 0tf , Sd ? l 5' °- 20% ; es *° ckin 9 fee for returned merchandise. DorosouthDS180 $1399 w/iroctor jr^ovv ^^ Warranties included on all products. COMPARE FLEXIBILITY. Model 950 \ • Advanced editing with wraparound • Smooth scrolling • 15 baud rates (SOB to 19.2kB) — Protected fields — Underlining • Split screen with line lock — Non-glare screen • Programmable function keys — 15 special graphics characters • Versatile screen attributes • Self test — 25th status line • Buffered auxiliary port • 14 X 10 character resolution • Integral modem option • Tillable screen needs and make it your own. It has the flexibility and brains to provide all the performance you need but is priced to make sense whether you need lO or 1 ,000. The TeleVideo model 950 detachable keyboard CRT Terminal has 11 special function keys— 22 functions with the shift key— that can readily be programmed to your requirements using 256 bytes of on-board RAM. \ on needn't ston there. You can change kevs. kev functions, even keyboard locations. And the (ISO's micro- processor based design means you can customize the firmware for your system. Of course the 950 has premium TeleVideo perfor- mance — advanced editing with wraparound, split screen with line lock, and smooth scrolling. It also features a special characters for powerful line _ Contact TeleVideo for a detailed brochure, or call to- day to discuss how you can use these capabilities to make this terminal uniquely yours. TeleVideo, Incor- porated, 2149 Paragon Drive* San Jose, CA 95131. (4081 946-8500. Nationwide Field Service is available from General Electric Service Shoos. fehMdeo COMPARE PRICE. CALIFORNIA llosla Mcsu (714) 5I57-BIMIS • San .low: (408) 94B-HIMMI • MASSACHUSETTS Boston «!I7> BMH-BS91 NEW YORK/NEW. JERSEY Paranius (»ll) 389-1331 • TEXAS Dallas (2141 BSO-9978 Circle 44 on Inquiry card. See us at NCC, booths 163-165 Digital Minicassette Controller James Kahn 2284 Ellena Dr Santa Clara CA 95050 The microcomputer-system design- er has had a difficult time finding low -cost storage devices. Frequently, the choices have been limited to either standard Phillips audio cassettes or floppy disks. Although these are relatively inexpensive storage media, the transport mechanisms, or drives, are not. In addition to the transport, a controller and data formatter is re- quired to interface the transport to the microcomputer system. The con- troller may either be a dedicated LSI (large-scale integration) device or be Commonly used mass- storage mechanisms and associated con- trollers are often quite expensive. built up discretely from SSI (small- scale integration) logic consisting of TTL (transistor-transistor logic) gates and flip-flops. Photo 1: The author's minicassette system includes an Intel iSBC 80/30 single-board computer and a Braemar CM-600 Mini-Dek transport. There is now another choice besides the floppy disk and the Phillips cassette: the digital mini- cassette. Not only is the storage medium inexpensive, so is the transport (about $140, versus $400 for a floppy-disk drive). As a bonus, the transport is extremely compact (only 23 cubic inches) and requires lit- tle power (1 watt). This makes it suitable for a wide range of low-end applications ranging from experimen- tal systems to data logging for test in- strumentation. There is one problem with designs using a minicassette: controlling it. There are several choices for the transport controller. One choice is to design a controller of discrete SSI logic. Although this choice will pro- vide good performance, it requires a handful of discrete components. The SSI controller will use much circuit- board space, compromising the ad- vantage of a compact transport. A better design would use a minimal number of components and take ad- vantage of current LSI technology. One such controller-design solu- tion is to use the Intel 8255A Pro- grammable Peripheral Interface IC (integrated circuit) to interface the transport to a microcomputer system. Although this design provides a sim- ple solution to the problem, the pro- cessor would be burdened with pro- viding the low-level control needed by the transport, in addition to sup- porting its normal real-time I/O (in- put/output) tasks. Examples of these low-level tasks are transport start-up, data formatting, and transport shut- down. There is, however, a better LSI solution available: distribute the system intelligence from the micro- 66 April 1981 © BYTE Publications Inc The best news since CP/M ... customizable full screen editing As a serious computer user you spend much of your time editing, whether it be for program development or word processing. Make the best use of your time with the help of VEDIT, an exceptionally fast and easy to use full screen editor. VEDIT is a highly refined and proven editor which is easy enough for novices to leam and use. Yet its unequalled set of features also makes it the choice of computer professionals. And because VEDIT is user customizable, it adapts to your keyboard, hardware, applications and preferences. In VEDIT, the screen continuously displays the region of the file being edited, a status line and cursor. Changes are made by first moving the cursor to the text you wish to change. You can then overtype, insert any amount of new text or hit a function key. These changes are immediately reflected on the screen and become the changes to the file. VEDIT has the features you need, including searching, file handling, text move and macros, plus it has many special features. Like an 'UNDO' key which undoes the changes you mistakenly made to a screen line. And a mode which allows a programmer to enter all text in lower case and let VEDIT convert the labels, opcodes and operands, but not the comments, to upper case. The screen writing is almost instantaneous on a memory mapped display or can use your CRT terminal's editing capabilities. Disk access is very fast too, and VEDIT uses less than 12K of memory. The extensive 70 page, clearly written manual has sections for both the beginning and experienced user. Totally User Customizable Included is a setup program which allows you to easily customize many parameters in VEDIT, including the keyboard layout for all cursor and function keys, screen size (up to 70 lines, 200 columns), default tab positions, scrolling methods and much more. This setup program requires no programming knowledge or 'patches', but simply prompts you to press a key or enter a parameter. The CRT version supports all terminals by allowing you to select during setup which terminal VEDIT will run on. Features such as line insert and delete, reverse scroll and reverse video are used on 'smart' terminals. Special function keys on terminals such as the HI 9, Televideo 920C and IBM 3101, and keyboards producing 8 bit codes or escape sequences are also supported. New Features and Support The new release includes disk write error recovery, indent and undent keys for structured programming, and the ability to insert a specified line range of another file at the cursor position. Versions for MP/M and the Apple II R SoftCard R are now also available. Ordering Specify the CRT version, your video board or microcomputer, the 8080/Z80 or Z80 code version, and disk format required. Standard Package: Disk and manual $110 Manual: Price refunded with software purchase 15 VISA and MASTER CARD Welcomed. Attractive Dealer Terms. CP/M and MP/M are registered trademarks of Digital Research, Inc. Apple 11 is a registered trademark of Apple Computer, Inc. SoftCard is a trademark of Microsoft. North Star • Heath H8/H89 TRS-80 Model II • MP/M • SuperBrain • Apple II SoftCard • Sorcerer • TRS-80 Model I • Most other CP/M R Systems with CRT or Memory Mapped Displays CompuView Products Inc. 618 Louise, Ann Arbor, Michigan 48103 • Telephone (313) 996-1299 Circle 45 on inquiry card. BYTE April 1981 67 Vector CCK 100, $49.80 (1-9) for S-100, IEEE696, Motorola Exorciser. f e rEM SYS - BUS PERIPh L BUS Figure 1: Internal block diagram of the 8741A/8041A Universal Peripheral Interface. I/O lines can be programmed as inputs or outputs; 8041A control-program memory must be factory programmed; 8741A memory is user-programmed. the two slave microcomputers. Each 8243 provides 16 programmable, bidirectional I/O lines. Using the 8741A allows the design- er to develop a custom peripheral in- terface for particular I/O problems. These devices have found applica- tions in such diverse areas as character-printer control, data en- cryption, keyboard control, and in- telligent displays. Developing an 8741 A design is straightforward. The designer develops a control algorithm using the UPI-41A cross assembler and programs the on-board EPROM of the 8741 A. Testing may be ac- complished using either an ICE-41A in-circuit emulator or the single-step mode of the 8741 A. The Hardware The complete microcomputer system is shown in photo 1, including the CM-600 minicassette transport. The microcomputer system for this design consists of an Intel iSBC 80/30 single-board computer. It supports an 8085A microprocessor, 8 K bytes of EPROM, and 16 K bytes of program- mable memory. In addition to an 8255A parallel interface and an 8251 A serial interface, it contains a Multibus system bus connector allowing expansion beyond the board's local resources. Incidentally, there is an 8741A socket built into the board as well. Let us examine the microcomputer- to-8741A hardware interface. The computer sees the 8741A as three registers in its I/O address space: the data register, the command register, and the status register. The decoding of these registers is shown in figure 2. Within the 8741A, both the data and commands are written into the same physical register, the Data Bus Buffer Input register (DBBIN). The state of the register-select input, Ao, deter- mines whether a command or data has been written (Ao = for data). All output to the microprocessor is read from the Data Bus Buffer Output register (DBBOUT). The status register is composed of 4 software-programmable bits and 4 reserved bits reflecting the state of the 8741A slave microcomputer (see figure 3 on page 78). The Input Buffer Full (IBF) bit and Output Buffer Full (OBF) bit reflect the state of the DBBIN and DBBOUT registers, respectively. Flag (F ) and Flag 1 (Fi) can be set and complemented via the LET YOUR APPLE SEE THE WORLD! The DS-65 Digisector® is a random access video digitizer which converts a TV camera's output into digital infor- mation the Apple can process. It features 256 X 256 resolution with up to 64 levels of grey scale. Scanning sequences are user programmable. On-board software in EPROM is provided for displaying digitized images on the Hi-Res screen. Use the DS-65 for: Precision Security Systems • Computer Portraiture • Robotics • Fast to Slow Scan Conversion • Moving Target Indi cators • Reading UPC codes, schematics, musi- cal scores and paper tape • NEW SOFTWARE FOR THE DS-65 IS NOW AVAILABLE ON DISK! — Portrait System Software: This program includes captions and a credit line, reverse printing for T-shirt application and the option to save por- traits on disk. — Picture Scanner: Provides a variety of differ- ent dithering algorythms for compressing the digitized image into the Hi-Res screen. Write or call for more information! THE DS-65 Price: $349.95 GIVE YOUR APPLE THE GIFT OF SIGHT! '/MX 11 O fi^Q) FS " Ca K mera Pri ° e: S2 ^9° nn Master Charge / Visa Accepted Z/V-Al U VS7 UN — ZZS Combination Price: $599.00 K W©\^^^ P.O. BOX 1110 DEL MAR, CA 92014 714-942-2400 70 April 1981 © BYTE Publications Inc Circle 47 on inquiry card. The Perfect Fit The Micromodem II data communications system and the Apple II* computer. What better combination to maximize the capabilities of your personal computer! This popular direct connect modem can transmit data between an Apple II and another Apple II, a terminal, another microcomputer, minicomputer or even a large time-sharing computer anywhere in North America. The Micromodem II has unique automatic dialing and answer capabilities which further increases the communications possibilities between the Apple II and another computer or terminal. You can send and/or receive messages or data when you are out of your office, home or out of town. Your branch business locations can communicate with each other regarding inventory and other matters over the phone. Or you can communicate with friends across the country. And you can access information utilities like the SOURCE for various business and personal applications. The Micromodem II consists of two parts. One part includes the printed circuit board which holds the Micromodem II, ROM firmware and the serial interface. The board plugs directly into the Apple II providing all the functions of a serial interface card plus programmable auto dialing and auto answer capabilities. The on-board ROM firmware enables the Micromodem II to operate in any of three modes to perform different tasks-terminal mode, remote console and program control mode. The other part of the Micromodem lldatacomm system is a Microcoupler which connects the Micromodem board and Apple II to a telephone line. The Microcoupler gets a dial tone, dials numbers, answers the phone and hangs up when a transmission is over. There are none of the losses or distortions associated with acoustic couplers. The Microcoupler is compatible with any North American standard telephone lines and is FCC-approved for direct connection in the U.S. It works with standard dial phone service or Touch-tone service. The Micromodem II is completely compatible with Bell 103-type modems. Full and half-duplex operating modes are available as well as speed selectable transmission rates of 1 1 and 300 bps. Why not increase your Apple ll's capabilities by outfitting it with the sophisticated Micromodem II data communications system? The Micromodem II is available at retail computer stores nationwide. For the store nearest you, call or write: fflHayes Circle 48 on inquiry card. Hayes Microcomputer Products Inc. 5835 Peachtree Corners East, Norcross, Georgia 30092 (404) 449-8791 ™ Micromodem II is a trademark of Hayes Microcomputer Products, Inc. * Apple II is a registered trademark of Apple Computer Inc. The Micromodem II can also be used with the Bell & Howell computer. internal software. The remaining 4 bits are used to indicate the status of the transport. The TTL-compatible I/O lines of the 8741A provide an uncomplicated interface to the CM-600 Mini-Dek minicassette transport (Mini-Dek is a registered trademark of Braemar Computer Devices Inc). The I/O lines can be divided into three groups: motor control, data control, and cassette status. These I/O port lines are shown in the 8741A interface schematic in figure 4 on page 78. The motor-group controls are go/stop, fast/slow, and forward /reverse. The data controls are read/write, data-in, and data-out. The remaining group of outputs reflects the CM-600's status: clear leader, cassette present, file pro- tected, and cassette side. The Braemar CM-600 Mini-Dek transport is representative of digital minicassette transports. The transport is compact, requiring only 3 by 3 by 2Vi inches for mounting. It has a single read/write head and uses only one drive motor. Operating from a 5 V supply, it has modest power-supply requirements, needing only 200 mA during a read or write. Tape speeds are 3 ips (inches per sec- ond) during read/write, 5 ips for fast forward, and 15 ips during rewind. Calculating the data-transfer rate based on the read/write speed and the maximum recording density of 800 bpi (bits per inch) yields a maximum data-transfer rate of 2400 bps (bits per second). A more useful represen- tation illustrating the significance of this number is obtained by inverting it. This yields the bit-cell period: 416 /as. This control requirement is easily met by the 8741A, its timer having a minimum resolution of 80 fis. If finer resolution were required, software- timing loops would have to be used. The maximum resolution is limited to the instruction-cycle time of the 8741 A, 2.5 /is, necessary for transfer rates of 8000 bps. Recording Format Since the CM-600 does not provide any data formatting, the 8741A must perform this additional low-level task. A multitude of encoding tech- niques are available from which the user may choose [ie: NRZ1 (Non- return to Zero, change if 1), Phase, GCR (Group Code Recording)]. For Introducing. . . MINI-FLEX Designed Specifically W^tt Ah The Newest Member of The Advance Access Diskette Protection Family For Further Information CALL TOLL FREE 800-323-3412 ADVANCE ACCESS GROUP 2200 S. Main St., Lombard, IL 60148 312-629-5800 "Manufacturers of Information Processing Supplies" this application, a "self-clocking" phase-encoding scheme similar to that used in floppy disks was selected. Phase encoding provides easy en- coding and decoding of the serial data, embedding the timing informa- tion and data bits together in the recorded bit cells on the tape. This is an effective means of compensating for speed variations of the drive. Reading the data is accomplished by using the clocking information of the bit cell to synchronize the sampling of the data bit coming from the transport. Figure 5 on page 78 illustrates this encoding technique as applied to the hexadecimal character 3A (all characters referenced in this article are hexadecimal). Notice that each bit cell begins with a transition to a logic level opposite the level of the preced- ing bit-cell level. Decoding the data is simply a matter of starting a timer on this "clocking" transition of the cell, waiting 3/4 of a bit-cell period, and determining whether a mid-cell tran- sition occurred. Cells with no mid- cell transitions are 0s; cells with tran- sitions are Is. Besides the encoding Text continued on page 80 8741A WR RD CS A0 DATA BUS c STATUS REGISTER \ DATA BUS J INPUT REGISTE DATA BUS OUTPUT REGISTER CS RD WR A REGISTER 1 DBBOUT 1 1 STATUS 1 DBBIN (DATA) 1 1 DBBIN (COMMAND) 1 X X X NONE 72 April 1981 © BYTE Publications Inc Circle 49 on inquiry card. Figure 2: 8741A system-bus interface and register decoding as seen by the host pro- cessor. Circle 50 on inquiry card. > First compare quality. Then compare cost. Morrow Designs 9 10 megabyte hard disk system: $3,695. MORE MEMORY. LESS MONEY. Compare Morrow Designs' DISCUS M26™ hard disk systems to any system available for S-100 or Cromemco machines. First, compare features. Then, com- pare cost per mega- byte. The M26 works out to under $200 a megabyte. And the M10 is about half the cost of com peting systems. COMPLETE SUBSYSTEMS. Both the M10 (8"), and the M26 (14"), are delivered complete with disk controller, cables, fan, power sup- ply, cabinet and CP/M® operating system. It's your choice: 10 Mb 8" at $3,695 or 26 Mb 14" at $4,995. That's single unit. Quantity prices are available. BUILD TO FOUR DRIVES. 104 Megabytes with the M26. 40+ megabytes with the M10. Formatted. Additional drives: M26: $4,495. M10: $3,195. Quantity discounts available. S-100, CROMEMCO AND NORTH STAR? The M26 and M10 are sealed-media hard disk drives. Both S-100 controllers incorporate intelligence to super- vise all data transfers through four I/O ports (command, 2 status and data). Transfers between drives and control- lers are transparent to the CPU. The controller can also generate interrupts at the completion of each command . . . materially increasing system through- put. Sectors are individually write-protectable for multi use environments. North Star or Cromemco? Call Micro Mike's, Amarillo, TX, (806) 372-3633 for the software package that allows theM26and MIOtorun on North Star DOS. MICAH of Morrow Designs' 26 megabyte hard disk system: $4,995. Sausalito, CA, (415) 332-4443, offers a CP/M expanded to full Cromemco CDOS compatibility. AND NOW, MULT-I/O.™ Mult-I/O is an I/O controller that allows multi-terminal and multi-purpose use of S-1 00 and Cromemco computers. Three serial and two parallel output ports. Real time clock. Fully program- mable interrupt controller. Designed with daisy-wheel printers in mind. Price: $299 (kit), $349 assembled and tested. MAKE HARD COMPARISONS. You'll find that Morrow Designs' hard disk systems offer the best price/ performance ratios available for S-100, Cromemco and North Star compu- ters. See the M26 and M10 hard disk subsystems at your computer dealer. Or, write Morrow Designs. Need infor- mation fast? Call us at (415) 524-2101. Look to Morrow for answers. MORROW DESIGNS •CP/M is a trademark of Digital Research Corp. 'Cromemco is a trademark of Cromemco, Inc. North Star is a trademark of North Star Computers, Inc. 5221 Central Avenue Richmond. CA 94804 PRINTERS ANADEX DP-9500 W/2K DUFFER, 1375 ANADEX DP-9501 W/2K DUFFER 1450 DASE 2 800-D 599 C. ITOH STARWRITER 25 CP5 1750 C. ITOH STARWRITER 45 CP5 2450 A. CENTRONICS 707 625 EPSON MX-70 W/GRAPHICS 449 D. EPSON MX-80 132 col .620 PAPER TIGER IDS-445 W/DOT PLOT 749 C. PAPER TIGER IDS-460 W/DOT PLOT '. . 1 1 95 PAPER TIGER IDS-560 W/DOT PLOT 1495 D. QUME SPRINT 5/45 2550 SILENTYPE W/INTERFACE 549 b. Tpriilii j£i SYSTEMS A. APPLE II PLUS 1 6K 1 049 APPLE II PLUS 46K (APPLE Memory) 1 1 69 APPLE II STANDARD MODELS CALL These are the newest models with FCC type approval to prevent RF interference. D. DISK II DRIVE & CONTROLLER 529 This model includes DOS 3.3 i6 sector DISK II DRIVE ONLY (ADD-ON) 445 C. CHALLENGER 4P by OHIO SCIENTIFIC 699 C4PMF (MINI FLOPPY SYSTEM) 1 599 OP MODEL II 449 SARGON II (DISK OR CASSETTE) 35 FIG FORTH (DISK ONLY) 69 D. PMC-60 THE TRS-80 WORKALIKE' 629 16K LEVEL II W/PROGRAM RECORDER, CALL OR WRITE FOR MORE INFORMATION E. EXIDY SORCERER II CALL AVAILABLE IN 16K, 32K & 48K MODELS 5-100 EXPANSION UNIT 375 WORD PROCESSING PAC 1 79 DEVELOPMENT PAC 89 F. ATARI 800 1 6K 799 ATARI 400 16K 499 810 DISK DRIVE 499 41 PROGRAM RECORDER 69 850 INTERFACE MODULE 175 VIDEO MONITORS k. AMDEX/LEEDEX VIDEO-100 12" DGW 139 HITACHI 1 3" COLOR 389 i. NEC 12" P31 GREEN PHOSPHER CALL PANACOLOR 1 0" COLOR 375 SANYO 9" D&W 179 :. SANYO 1 2" D&W 255 SANYO 1 2" P31 GREEN PHOSPHER 295 SANYO 1 3" COLOR 445 SHOPPING MAIL ORDER? CALL US TODAY! We probably have what your' re looking for in stock ot an incredible price. Our company is an authorized dealer for sales and service for Apple Computer. Atari and Ohio Scientific, if you receive a defective product from us we will repair or replace (at our option) any product in warranty, Our Service Center will repair all Apple Computer products, in or out of warranty, whether it was purchased from us or another dealer, (call for more details) PHONE ORDERS IN CALIFORNIA, ALASKA, HAWAII & FOREIGN (714)698-8086 SHIPPING INFORMATION OR DACKORDERS PLEASE CALL (71 4)696-0260 SERVICE CENTER AND FOR TECHNICAL INFORMATION (714)460-6502 74 BYTE April 1981 Circle 51 on Inquiry card. Order Dept. Open Every Day 9a.m. - 6 p.m. P.5.T. TOLL FREE ORDER LINE 600-854-6654 We honor these cords AMERICAN] . <•> APPLE HARDWARE Y APPLE SOFTWARE TOP FIVE SELLERS LANGUAGE SYSTEM W/PASCAL. ... 425 SILENTYPE PRINTER W/INTERFACE. 549 HAYES MICROMODEM II 319 VIDEX VIDEOTERM 80 w/graphics. 335 Z-80 MICROSOFT CARD 299 APPLE COMPUTER INC. DISK II DRIVE ONLY 445 INTEGER OR APPLESOFT II FIRMWARE CARD 155 GRAPHICS TABLET 649 PARALLEL PRINTER INTERFACE CARD 155 HI-SPEED SERIAL INTERFACE CARD 155 COMMUNICATIONS INTERFACE CARD 185 SMARTERM 80 COLUMN VIDEO CARD 335 MOUNTAIN COMPUTER INC. MUSIC SYSTEM (16 Voices) 479 A/D + D/A INTERFACE 319 EXPANSION CHASSIS 555 INTROL/X-10 SYSTEM 249 CLOCK/CALENDAR CARD 239 SUPERTALKER SD-200 249 ROMPLU5 + CARD 135 ROMWRITER CARD 155 CALIFORNIA COMPUTER SYSTEMS CLOCK/CALENDAR MODULE 1 09 GPID IEEE-488 CARD 259 ASYNCHRONOUS SERIAL INTERFACE CARD 1 29 CENTRONICS PARALLEL INTERFACE CARD 99 We carry all CCS hardware. Please call MISC. APPLE HARDWARE 16K RAM UPGRADE (Apple, TRS-80. Exidy) 189 1 6K RAM CARD MICROSOFT 1 89 ACT NUMERIC KEYPAD (old or new kybrd) 115 ADT BAR CODE READER WAND 179 ALF 3 VOICE MUSIC CARD 229 ALF 9 VOICE MUSIC CARD 1 69 ALPHA SYNTAURI KEYBOARD SYSTEM 1 399 BIT 3 FULL VIEW 80 CARD 349 CAT NOVATION ACOUSTIC MODEM 1 69 CORVUS 1 0MB HARD DISK CALL LAZER LOWER CASt PLUS 50 MICRO-SCI DISK DRIVES CALL PAYMAR LOWER CASE (old or new Kybrd) 55 RADCOM AMATEUR RADIO INTERFACE CARD 189 SPEECHLINK 2000 HEURISTICS 229 SSM AIO SERIAL/PARALLEL CARD A&T 1 89 SUP-R-TERMINAL 80 COL. CARD 339 SVA 6 INCH FLOPPY DISK CONTROLLER 345 VERSAWRITER DIGITIZER PAD 229 VIDEX KEYBOARD ENHANCER 115 We stock much more than listed. Please call. APPLE COMPUTER INC. DOS TOOLKIT 65 APPLEPLOT 60 TAX PLANNER 99 APPLE WRITER 65 APPLE POST 45 DOW JONES PORTFOLIO EVALUATOR 45 DOW JONES NEWS G QUOTES REPORTER 85 APPLE FORTRAN 165 APPLE PILOT 129 DOS 3.3 UPGRADE 49 MUSIC THEORY 45 THE CASHIER Retail Mngmnt & Inv 1 99 THE CONTROLLER Gen. Bus. Sys 519 MISC APPLICATIONS PACKAGES VISICALC 125 DESKTOP PLAN II 1 69 CCA DATA MANAGMENT DMS 85 EA5YWRITER WORD PROCESSOR 225 EA5YMOVER MAIL SYSTEM 225 EASYMAILER LETTER WRITER 225 ASCII EXPRESS 65 MICROSOFT FORTRAN 185 MICROSOFT COBOL 695 MICROSOFT BASIC COMPILER 375 SUPER TEXT II 139 PROGRAMMA APPLE PIE 119 THE LANDLORD Apt Mngmnt package 649 PEACHTREE BUSINESS SOFTWARE CALL TAX PREPARER by HowardSoft 89 APPLEBUG ASSEM/DISASSM/EDITOR 75 3-D GRAPHICS By Bill Budge 53 SUPER FORTH 49 TOP TEN GAMES APPLE GALAXIAN 23 FLIGHT SIMULATOR 34 THE WIZARD AND THE PRINCESS 32 COSMOS MISSION (SPACE INVADERS) 24 SARGON II CHESS 32 HI-RES FOOTBALL 39 COMPUTER QUARTERBACK 39 ADVENTURE BY MICROSOFT 27 PHANTOMS FIVE 39 REVERSAL (OTHELLO) 34 CALL OR WRITE FOR A COMPLETE SOFTWARE LIST ORDERING INFORMATION, Phone Orders invited using VISA MASTERCARD AMERICAN EXPRESS DINERS CLUB CARTE BLANCHE or bonk wire transfer Credit cords subject to service chorge 2% for VISA (j MC 5% for AE DC 6 CB Moil Orders may send credit card account number (include expiration date) cashiers or certified check money order or personal check (ollow 10 days to dear) Pease include o telephone number with oil orders Foreign orders (excluding Military PO s) odd 1 0% for shipping all funds must be m US dollars Shipping handling and insurance m U S odd 3% (minimum $4 00). California residents add 6% sales tax We accept COD s under S500 OEMs Institutions Corporations please send for written quotation AH equipment is subject to price change ond availability without notice All equipment is new and complete with manufacturer warranty (usually 90 days) We cannot guarantee merchannbility of any produces We ship most orders withm 2 days WE ARE A MEMDER OF THE DETTER BUSINESS BUREAU AND THE CHAMDER OF COMMERCE SHOWROOM PRICES MAY DIFFER FROM MAIL ORDER PRICES. PLEASE SEND ORDERS TO: CONSUMER COMPUTERS MAIL ORDER 8014 PARKWAY DRIVE, GROS5MONT SHOPPING CENTER NORTH LA MESA CALIF. 92041 Circle 51 on inquiry card. 10 DAY FREE RETURN NEC THE FIKST NAME IN LETTER QUALITY PRINTERS. CompuMart ofleis beautiful print quality with NEC Spinwriter ter- minals. Both KSR and RO versions give unsurpassed hard copy out- put CALL CENTRONICS PRINTERS The incredible Model 737. The closest thing to letter quality print tor under SLOOO. 737-1 (Parallel Interlace)— $899. NEW FROM INTEGRAL DATA- THE IDS 560 PRINTER. 132 column graphics printer. $1,695 IDS 445. Priced lower than the 440 and equipped with a better print head. IDS 445 w/graphics $894. IDS 445 w/o graphics $795. IDS 460 $1,295 The 460s features include Corre- spondence quality printing, high resolution graphics capability, programmable print justification Dysan Diskettes— Single side. Single density, Hard or Soft Sector $5. ea Memoiex 3401's— 5 Vt discs $3.25 with hub ring lor Apple $3.50. Memory Integrated Circuits— Call tor qty. discounts when ordering over 50 units. Motorola 4116 (2CO Nanosecond Plastic) $4.50 ea Faircliild 2114 (Standard Power, Plastic) $450 ea Super Selling Terminals We have the following Lear Siegler Terminals in stock at prices too low to print— Call for quotes ADM— 3A Indus- tries favorite dumb terminal for some very smart reasons. ADM— 3A + NEW from Lear Siegler. CALL! IT IS HEREI-It is the new Intermediate Terminal from Lear Siegler. Call lor details. Omni Printers from Texas Instruments The 810-List $1895. SALE! $1795. The 820 (Ro) Package- Includes machine-mounted paper tray and cable. A com- pressed print option and device forms control are standard fea- tures $2,155. The 820 (KSR) Package- Includes full ASCII Keyboard plus all of the features of the RO $2395. COMPUMART stocks the com- plete line of MATROX PRODUCTS. Call for specs COMPUMART now offers the ENTIRE DEC LSI-11 PRODUCT LINE. Call tor prices 8t delivery. NOVATION CAT 1 ™ ACOUSTIC MODEM Answer Originate. 3CO Baud, Bell 108, Low Profile Design $179.00 NEW! D-CAT Direct Coupler from Novation $199. We bare the following best- selling Hazeltine terminals in stock at prices much too low to print (1410. 1420, 1500, 1520, 1552) Call COMPUMART Now for our lowest prices ever. HP-41C Calculator $239.00 Memory Modules. For storing programs or up to 2.000 lines ol program memory $29.95 "Extra Smart" Card Reader. Records programs and data back onto blank magcards. t $199.00 The Printer. Upper and Lower case. High resolution plot- ting. Portable Thermal operation $355.00 Application Modules $29.95 NEW SUPER 41-C Systems with Quad RAMS built-in (Maximum memory onboard leaves slots open for Application Pacs and peripherals. The HP 41C C$325.00 HP 41C-C Plus Card Reader $495.00 HP 41C-C Plus Card Reader 8c Printer $845.00/ Quad RAMS for the 41-C < (Equivalent to lour Memory Modules^ all packed into one) $95.00 COMPUMARTs Microflex 65 Sys- tem lor your AIM Includes Adapter Buffer Module w/4-slot module stack. 8K RAM module, 16K PROM/ROM module. Asyn- chronous communications Inter- face, and Power Supply $1,299 Call or write lor our complete Microflex 65 brochure NEW IN STOCK: The PMC-80. The new computer that's software compatible with the TRS-80. Level II 16K at $645. ACCESSORIES FOR PMC-80 EXP-lOO S-lOO Bus Expander Disk Printer, RS232 I/O $410. S-32K S-lOO Bus 32K RAM Board tor EXP-lOO $295 CAB-40 Cable 12 " long ribbon cable lor EXP-lOO $25. Visit our giant ANN ARBOR STORE 1250 North Main Street Ann Arbor, Michigan ROCKWELL AIM 65 Our AIM system includes 4K AM with BASIC interpreter assembler, Power Supply, Cassette recorder 8c Enclosure $799. 4K AIM-65 $499. PL65 High Level Language $125. Paper lor the AIM (roll) $2.50 Rockwell's 4-slot Motherboard (sale) $175. Fourth lor Rockwell AIM 65 $175. SEND FOR OUR FREE CATALOG EXCLUSIVE from COMPUMART! Special Oiler. Zenith Color Video Monitor for $379! NEW FROM SANYO-Four Great Monitors at Low COMPUMART Prices Sanyo's new line ol CRT data display monitors are designed tor the display ol alphanumeric or graphic data. 9 " Sanyo Monitor $169. 12 " Sanyo Monitor $289. 12 " Sanyo Monitor with green screen $299. 13 " Sanyo Color Display Monitor $495. HP-35— Hewlett-Packard's Per- sonal Computer for Industry. This extremely portable computer features extended BASIC to solve your problems quickly and effi- ciently along with an advanced graphics system to enhance communication HP-85 ACCESSORIES— We carry HP. Peripherals (Disk Drives to Graphics Plotters) Enhancements (BASIC Training. General Statis- tics. Financial Decision Math. Lin- ear Programming $95 ea). HP-85 Accessories; (Enhancement ROMs ROM drawer. Overhead Transparency Kit).- Supplies (Plot- ter Pens, Tape Cartridges), Inter- face Modules (HP-IB Interface, HP-IB Interconnect Cables, Serial (RS-232C) Interlace Module). We can get your every HP peripheral made tor the HP-85. VBICALC PLUS FOR HP-85 Every thing you ever wanted from Visi- calc plus plotting. $200. HP83 VIRGO Has the same com- puting power as the HP85 with- out the added cost of tape drive and printer, for use with disc drives and optional printer/ plotter accessories. CALL FOR COMPLETE DETAILS 8c SPECS. COMPUMART exclusive ATARI SPECIALS— ATARI 8CO Personal Computer System— Comes with 8CO operators Manual 16K Rany Memory module, lOk ROM Operating System Power, Supply, TV Switch Box $950. PERIPHERALS Atari 410 Program Recorder $89.95 Atari 810 Disk Drive (SlOO off with purchase) $699.95 NEW Dual Disk double density $1499.95 825 Printer (Centronics 737) S995.00 RS232 Interface w/Cable $249.95 NEW! Light Pens $74.95 NEW! Visicalc for Atari $199.00 Educators Take Note. Atari has extended its 3 for 2 deal until 6- 30-8L Any educational institution that buys two Atari 800s will receive an Atari 400 computer absolutely FREE. Call our sales dept tor complete details. TMPOKTANT ORDEBDJG INFORMATION All Orders must include 4% shipping and handling. Mass. residents add 5% sales tax. Michigan residents 4% tor sales tax Phones open trom 830 a.m. to 700 p.m.. Mon-Fri. 11:00 am. to 400 p.m. Sat P.O.'s accepted from Dun & Biadstreet rated companies— shipment contingent upon receipt ol signed purchase order. Sale prices valid tor month ol magazine date only— all prices subject to change without notice. Our Ann Arbor retail store is open 1LOO a.m. to 7,00 p.m. Tues-Fri, lOOO a.m. lo 5,00 p.m. Saturdays. apple n We cany the most complete inventory ol Apple computers, peripherals, and software. CALL! Our Best Selling Apple System. Save over S250 on our most pop- ular Apple System. System includes a 48K Apple n. Apple Disk. DOS3.3. & Controller, and a Sup R. Mod RF Modulator. List $2209. COMPUMART Sale Price: $1895. SOFTWARE FROM APPLE Apple Plot The perfect graphic complement for Visicalc. S70 Dow Jones News & Quotes $95 Adventure (Uses 48K) $35 DOS Tool Kit $75 Apple Fortran $200 Tax Planner $120 FROM PERSONAL software Visicalc $149 Desk Top Plan $99 NEW FROM MUSE The Voice $39.95 Super Text $150 Address Book $49.95 Miscellaneous Apple n Accessories: Easy Writer (80 col need a Videx) $249 Easy Mover $49 Easy Mailer $69 NEW from Apple lor the Apple DOS 3.3 Convert disks to 16 sector format for 23% more storage and faster access $60. NEW lor the Apple n From Microsoft 16K RAM Board $195.00 FORTRAN $175.00 COBOL $750.00 Card Reader from Mountain Hardware $1,195.00 H-Res Dump for 460 Printer from the Computer Station $49.95 HARDWARE ACCESSORIES FOR APPLE Silentype Printer w/x face $635 Super Sound Generator (mono) $159 (stereo) $259 Light Pen $249 X-IO Controller (plugs into pad- dle port) $49 Mountain Computer— Expan- sion accessories for your Apple Introl-lO System $289 Super Talker $299 The Music System $545 ROM plus board w/Keyboard filter $199 Clock Calendar $280 16 Channel A to D Converter $35Q Apple Expansion Chassis $650 ROM Writer $175 From VIDEX!— Video Term. 80 Cot x 24 line. 7x9 Matrix plug in compatible board for the Apple n. Price $325 without graphics EPROM. With graphics EPROM $350. S.S.M Serial & Parallel Apple Interface $225 ABTs Numeric Key Plan $UO California Microcomputer Keyboard $195 Apple m is in stock— CALL! Commodore Strikes Back! CompuMart carries the entire Commodore line ol computers, peripherals, and accessories— call our sales force today for complete prices and specs The CompuMart/ Commodore Word Processing System Get crisp, letter quality output and ease of operation that's unsurpassed. This system includes a Commodore 8032 32K CPU. a 4040 Dual Disk, a C-Itoh printer and X/face. and Word Pro 4 Plus (all cables included). Call (or details and low prices. List S5685. COMPUMART $4995. A complete system including a Dual Disk Drive. Tractor Printer, and an 80 column 32K CPU lor under 34,000. No interfaces needed. Cables included. List S3.985. CompuMart $3635 New accessories irom Commodore lor Commodore Visicalc $199 Word Pro 4 $299 Ozz the Information Wizard $395 Wordcralt 80 $395 Tax Preparation Planner $495 Dow Jones Portfolio Manage- ment System $149 Personal Tax Calculator $69 PASCAL Development Packaae $295 Assembler Development Fackage $99 Educators Take Note!! Commo- dore has extended its 3 for 2 deal until 6-30-81. Complete Word Processing System for Under $5,000! COMPUMART has been serving the computer needs of industry since 1971. We stock, for immediate shipment, only those products from the finest micro-computer manufacturers. And any product, except software, can be returned within lO days for a full refund even if you just change your mind. We also honor all manufacturers' warranties. Our expert technicians will service any product we sell that cannot be better, or faster, serviced by the man- ufacturer's local service center. Call us for more information on products, product configuration and service. Our phones are open Monday thru Friday, &30 a.m. to 700 p.m. and Saturday 1LOO a.m. to 400 p.m. We have a staff of highly knowledgeable sales people waiting to hear from you, and to help. Because service is what we're all about. 800-343-5504 — iA* SYSTEMS, n In Mass. Call 617-491-2700 COMPUMART ' 65 BENT STREET, DEPT. 115, P.O. BOX 568 'CAMBRIDGE, MA 02139 Circle 52 on inquiry card. The joy of music — without years of practice! ALF offers the very finest in music hardware and software for the Apple® II. You can enter your own songs from sheet music and play them back very easily — our de- tailed manual shows you how, step by step. And there's a growing library of preprogrammed songs available too — now over 115 songs on 7 "albums", priced under $15 each. ALF's highly acclaimed music software has many features found on no other Apple music product — and no customer has ever reported a "bug" or error. Whether you pick our exciting 9-voice MCI music card at just $195, or our gourmet 3-voice MC16 card at $245, you'll get ALF's top- quality hardware that's famous for reliability and clean sound (we've been designing computer-controlled musical instruments since 1975). So see your Apple dealer today, and be sure to specify ALF music cards for the best performance. When you've seen ALF's total music package, you'll know why some music cards are more equal than others! Please mention this magazine when requesting information from: <3|\ A L F Products Inc. ^1/ 1448 Estes Denver, CO 80215 (303) 234-0871 Apple is a trademark of Apple Computer Inc. EAR TRAINING Four programs (pitch discrimination, interval recognition, chord recognition, and scale recognition) for the ALF MC16 music card (described above) are available on disk (or cassette). Under $50 for the set, see your local Apple dealer. For more information write: ALF Products Inc. 1448 Estes Denver, CO 80215 (303) 234-0871 STATUS REGISTER 0BF - OUTPUT BUFFER FULL ■ IBF - INPUT BUFFER FULL •F - FLAG (USER DEFINED) • Fj - FLAG 1 (USER DEFINED) - DRIVE ACTIVE -FILE PROTECT -CASSETTE PRESENT - BUSY Figure 3: Definitions of the status-register bits; Flag and Flag 1 may be controlled by the user via the internal software. + 5V A C=_) 0BF IBF vcc VDD cs RD WR A0 SS 3 • TEST 1 p 20 '14 »-C RESET Pl5 P 16 EA V S S 7 MOTOR POWER LOGIC POWER DATA-OUT DATA - IN FORWARD/REVERSE FAST /SLOW READ/WRITE CLEAR LEADER FILE PROTECT CASSETTE PRESENCE POWER GND SIGNAL GND CHASSIS GND Figure 4: The interface between the CM-600 Mini-Dek, the 8741A, and the host system. r:\ -MID-CELL- -CLOCKING TRANSITION LOGIC LEVEL 1 LOGIC LEVEL Figure 5: The hexadecimal character 3 A phase-encoded. This is the algorithm used with the minicassette controller. It is not the logic level of a bit cell that determines its value, but the presence or absence of a mid-cell transition. 78 April 1981 © BYTE Publications Ire In this age of runaway inflation... Look what $795* will buy The ideal input device for the small system user. Ei 55 K£j «mo 2™-; **« «'»-* C7UM ««-* m« E'^l _\ 735-00 2n£i iltS IS »! tiki rvt ; ^| ■»' iiii ■M ^H HiMt IBI -Wll iwr fj:r -i .r-.v ^^F^^^^^^K* sn; iss Available with stylus or optional cursor. The HIP AD™ digitizer Inexpensive input to your computer The HIPAD™ digitizer can be used for both converting graphic information into digital values and as a menu. Utilizing either the stylus or the optional cursor, the operator can input graphic data into the computer by locating individual points on the digtizers 11" x 11" (28cm x 28cm) active area. In the "stream mode" a contin- uance of placements of coordinate pairs may be input. Not a kit, the HIPAD™ comes complete with both RS-232C and parallel interfaces and has its own built-in power source. The origin is completely relocatable so coor- dinates may be positive or negative for a true reference value and oversized mater- ial may be input by simply resetting the origin. Accurate positional information, free form sketches, even keyboard simulation All can be entered using the multi-faceted HIPAD™ digitizer. Its capabilities and low price make the UL listed HIPAD™ a natural selection over keyboard entry, inac- curate joysticks, or expensive approximating light pens. It's perfect for inputting isometric drawings, schematics, X-rays, architectural drawings, business graphs, and many other forms of graphic information, as well as creating your own graphics. Use it with Apple II™ , TRS-80 Level II ™ , PET ™ or other popular computers The HIPAD's™ built-in RS-232C and parallel 8 bit interfaces make it all possible. (For Apple II order DT-11A, for TRS-80 or PET order DT-11). Furthermore, you get English or metric scaling, data format (Binary/BCD/ASCII), selectable baud rates, and resolution of either .005" or .01". For complete information contact Houston Instrument, One Houston Square, Austin, Texas 78753. (512)837-2820. For rush literature requests, outside Texas call toll free 1-800-531-5205. For technical information ask for operator #5. In Europe contact Houston Instrument, Rochesterlaan 6, 8240 Gistel, Belgium. Telephone 059/27-74-45. Available with optional display. 'U.S. Suggested retail price TM HIPAD is a trademark of Houston Instrument TRS-80 is a trademark ot Tandy Corporation APPLE is a trademark ol Apple Computer Inc. PET is a trademark of Commodore Business Machines, Inc. Circle 53 for literature Circle 54 to have representative call houston instrument GRAPHICS DIVISION OF BAUSCHSLOMB ▼ Text continued from page 12: scheme, the data format is also up to the user. The 8741A reads and writes blocks of variable length with an 8-bit checksum for error detection automatically appended. An option is to use the 8741A to check for errors by generating a CRC (cyclic redun- dancy check) code instead of a checksum, as in the CRC-16 error code used for floppy disks. A block starts with a Sync character (hexadecimal AA), fol- lowed by the data (up to 64 K bytes), which is in turn followed by the checksum byte and trailing Sync character. Blocks of data are separated by an IRG (inter-record gap). The IRG is such a length that the transport can stop and start within an IRG. The CM-600 drive specification calls for a worst-case start or stop time of 150 ms. A 450 ms IRG was selected for the 8741A to allow plenty of margin for both controlling the transport (ie: starting and stopping) and detecting an IRG during the SKIP operation. The 8741A Controller Software The goal of the software design for this application was to make the UPI- The popular Sams series of Computer Primers provide a working knowledge of computers without being dry and com- plex. The Primer Books guide you through the subject at an easy pace. Your jour- ney to understanding is short, exciting, and fun. The Sams Primers offer good graphics ... a good balance of data ... an upbeat, positive style . . . and are organized so that you can read them straight through like a novel. CP/M™ PRIMER, by Mitch Waite and Stephen Murtha. A non-technical discus- sion of CP/M disk operating systems for 8080 and Z-80-based microcomputers. No. 21791. $11.95. PASCAL PRIMER A complete guide to the hottest new language in computers by Mitch Waite and David Fox. No. 21793. $16.95. COMPUTER GRAPHICS PRIMER An easy- to-understand guide to creating draw- ings, plans, maps, and schematics on a computer monitor. By Mitch Waite. No. 21650. $12.95. MICROCOMPUTER PRIMER (Second Edi- tion) Up-to-date facts on popular mic- rocomputers. Don't buy a computer without reading this book by Mitch Waite and Michael Pardee. No. 21653. $11.95. BASIC PROGRAMMING PRIMER A valuable guide to BASIC, today's most widely used microcomputer language. By Mitch Waite and Michael Pardee. No. 21586. $10.95. Sams Books. Mail To: Howard W. Sams & Co., Inc. 4300 West 62nd Street P.O. Box 7092 Indianapolis, IN 46206 Saw 1 0% on Orders of S20 oi More! Quonlity — Money Order CP'M Primer PASCAL Primer Computer Graphics Primer Microcomputer Primer BASIC Programming Primer No. 21791 Sll 95 No. 21793 $16 95 No. 21650 $12.95 No. 21653 $11.95 No. 21586 $10.95 Amount ol order $ Deduct 10% it order is $20 or more $ Add local sales lax where applicable $ Shipping & handling costs $2.00 Total amount of order $ Payment Enclosed Check VISA MasterCard Interbank No. _ Accounl No Expiralion Dale. Name (print) Signature Address City. Stdfe -Zip- Prices good in U S.A. only Prices subject to change without notice CALL TOLL-FREE I -800-128-3696 for the name ol your local Sams Book oullet or to order by phone. Offer expires 7 '31 '81 AD08I 41A microcomputer into an in- telligent cassette-control processor. The host microprocessor (8085A, 8080A, 8088, etc) issues a high-level command such as READ or WRITE to the 8741A, which accepts the com- mand and performs the requested operation. Upon completion, it returns a result code notifying the mi- croprocessor of the outcome (eg: Good-Completion, Sync Error, etc). Table 1 on page 92 lists the high-level command and result codes for the functions performed by the minicassette controller. The internal 8741A software can be roughly divided into the various com- mand functions. At the top of the hierarchy is the command recognizer. Its job is to get a command from the f WRITE J GET CNTLSB/ CNTMSB YES Terror exit j INITIALIZE VARIABLES AND START TIMER START TRANSPORT (error EXIT J WRITE IRG AND STOP TRANSPORT C EX ' T ) Figure 6: Flowchart of the WRITE com- mand sequence. SEE THE COMPLETE SAMS LINE AT NCC. BOOTH #5209. Circle 55 on inquiry card. New power at your fingertips. Konan presents Hard Disk Control, Tape Control, and Serial I/O Boards for S-lOO computers. Konan, known throughout the industry for its leading, innovative, guaranteed controllers for S-lOO systems, does it again. Now, it offers you more of the expanded capabilities you want. Take your pick to suit your needs. There's the SMC-lOO™ storage module (SMD or CDC 9760 interface) hard disk controller. There's the HARDTAPE™ subsystem which offers Winchester hard disk control with tape back up. Or maybe you could use Konan's new KNX-500, software compatible with the AM-500*, for lO megabyte fixed/ removable media hard disks. The "DAVID" is Konan's new error-correcting intelligent disk controller for 5 1/4" and 8" Winchester hard disk drives. And the "ENHANCER" is an intelligent reel-to-reel tape controller with high speed printer port for spooling, offline sorts, copies, etc. Watch for new controllers coming soon! Also, Konan introduces OCTOPORT™ and OMNIPORT™-two new serial I/O boards. OCTOPORT™, the 8-port board, offers a real time clock and full interrupt control. And the 16 port OMNIPORT™ offers you an efficient, economical board where more than 8 ports are needed. With these and other quality products, Konan shows again that when it comes to S-lOO systems, it is definitely in control. (And all at attractive OEM. and dealer prices.) Call Konan's toll-free order line : 800-528-4563. Or write to: Konan Corporation 1448 North 27th Avenue Phoenix, AZ 85009 TWX/TELEX 9109511552 'Alpha Micro AM-500 is a irademark of Alpha Micro Systems. IN CONTROL. SMC-lOO, HARD TAPE, KNX-500. OCTOPORT, and OMNIPORT are trademarks ot Konan Corporation. Circle 125 on inquiry card. Circle 56 on inquiry card. ^&^ S-100 PROGRAMS MOST FAMILIES OF EPROMS! • ACCEPTS 1K/2K/4K OR 8K EPROMS! • EXTENDED DEVICE OPTION • PHANTOM SLAVE OPTION • ALL PROGRAMMING CHARACTERISTICS SOFTWARE CONTROLLED! • ACCEPTS SINGLE OR 3 SUPPLY PARTS • DEVICE ADDRESS SWITCH SELECTABLE • ON-BOARD WAIT STATES Put your frequently used routines into EPROM! Bare board $59.95 Software $55.00 Together $99.95 + 2.5% for shipping ^ S-100 "CLUGE CATO SIMPLIFY YOUR PROJECTS WITH A PROTOTYPE BREADBOARD WITH EXTRAS! • 4 ON-BOARD PWR. SUPPLIES UP TO 3 OF WHICH CAN BE +5, or ±5, ±12 • SWITCH SELECTABLE MEMORY OR DEVICE ADDRESS • ON-BOARD ADDRESS/ DEVICE DECODING • BI-DIRECTIONAL DATA BUS BUFFERING • ON-BOARD WAIT STATES • LARGE BREADBOARD AREA Bare board $39.95 + 2.5% for shipping MASTERCARD/VISA CHECK OR MONEY ORDER ILL. RES. ADD SALES TAX ACKERMAN DIGITAL SYSTEMS, INC. 110 N. YORK RD., SUITE 208 ELMHURST, ILLINOIS 60126 (312) 530-8992 NO COMPLEMENT TAPE INPUT YES GET NEXT BIT OF CHARACTER F n =0 C Em ) < ^bit \,_ NO 3 jr YES COMPLEMENT BIT ' /CHARACTERS. YES \WRITTEN yS NO GET NEXT CHARACTER ' GENERATE CHECKSUM ( EX ' T ) Figure 7: Flowchart of the WRITE interrupt routine. microprocessor and branch to the ap- propriate command routine, ex- ecuting until either the operation specified by the command is complete or aborted by the microcomputer or CM-600. The command routine then returns to the command recognizer to await the next command. Since only one command routine can be in ex- ecution at any one time, the working registers can change function based upon which command is active. These register names were assigned according to their function to aid pro- gram clarity. To understand the operation of the controller, let us ex- amine the flow of the various com- mands in greater detail. WRITE Command When the WRITE command is issued by the microprocessor, the 8741A expects a 16-bit unsigned number specifying the number of bytes to be written onto the tape to follow immediately. The controller requests only the desired number of data bytes by keeping track of the transfer count internally. All data transfers to and from the computer are double buffered. Before starting the transport, the 8741A checks the transport's status, verifying that the cassette is present and writing to the tape is not inhibited. If the drive is not ready for the data transfer, an ap- propriate error code will be returned; otherwise, the transfer will com- mence. The flowchart of this function is diagrammed in figures 6 and 7. The controller begins the block transfer by writing a 450 ms IRG, followed by the leading Sync character, the data, the checksum character, and the final Sync character. The data is encoded with the phase-encoding algorithm described earlier before being written onto the tape. The internal timer is Text continued on page 86 82 April 1981 © BYTE Publications Inc When You Have To Face A Deadline Arm Yourself With Pascal/MT+® NOW! THE PACKAGE INCLUDES OUR EXCLUSIVE PASCAL ORIENTED SCREEN EDITOR. You know what a monster a deadline Pascal/MT+ Features: Totally Portable: can be if you have to face it without the Pascal/MT+ has been designed from the proper tools. Arm yourself with an An International Standard: beginning to generate code for many dif- integrated set of programs, designed Pascal/MT+ conforms to the ISO Standard ferent microprocessors. Pascal/MT+ pro- from the beginning for production use, for Pascal, our competition doesn't even grams youcreate today can bere-compiled all tuned to the single goal of producing come close! A report on the performance to run on a more powerful machine reliable software Pascal/MT+ is a fully of Pascal/MT+ on the Pascal validation tomorrow. All of the extended language integrated program production system suite is included with each compiler. features are present in every version of the inrlnriinn nnr rnmnilpr riphimnpr dis- compiler. This means you won t have to assembler and hnker start over when the customer demands Used by many companies, large and Modular Program Compilation: small, Pascal/MT+ produces high quality The Pascal/MT+ modular compilation Extensions: reliable products in an amazingly short ™ ch anisrr , allows 5 construction of fully Pascal/MT+ has extensions to the amount of time. Our run-time library ^f^S^ , oHSr! dS Pascal language too numerous to describe contains all the tools needed to begin ^Zml^Siie\nVBr 9 SiS^ in detail here ' 0ur 160 page user ' s 9 uide program construction immediately. 3°% a ^ r ^ acritlce m either space or describes the features and gives examples Pascal/MT-*- produces efficient, small y ' of how to use them. A short summary of native machine code demanded by features is listed below: dynamic strings, today's product developers. All of our , flirio „ t Matiuo rnrio BCD amd h F oat ' n ? P '^ reals ' AMD9511 lihraru rnntinpc; qnd fpatnrps wnrk Efficient Native Code: support, bit, byte and unsigned word 6x3/ the same on 16 bit svstems as All versions of Pascal/MT + produce effi- manipulation, I/O port access, a full imple- exactiy tne same on lb-Dit systems as rnmnart NATIVE OBJECT CODE In an mentation of the NEW and DISPOSE heap they do on 8-b.t systems so you can ? n e d n e ^^ and many others, increase your capability without re- performed all other Pascal compilers on T writing any of your software. Your our target machjnes )n addition it pro- Target Machines: production quality products demand duced the smallest final programs by Available now 8080, 8085 and Z80 production quality tools. Order including only the minimum run-time Available soon 8086,8088 Pascal/MT+ now, call us today! overhead necessary. Coming 68000, 6809 and Z8000 See us at West Coast Computer Faire, booth 1608 PHcirKT rFja^S 1 ilf^nn / MT Micro SYSTEMS \ 8080/Z80 - $250.00 Cash, Check, UPS, C.O.D., L X As of 4/7/81 _ $47500 Mastercard, VISA, 1562 Kings Cross Drive Others Call Company P.O. Cardiff, California 92007 (714)755-1366 Communication Arts. Huntington Beach. CA "BEST PRINTER VALUE IN THE WORLD" Check our prices on THE ULTIMATE IN QUALITY Epson Printers APPLE & MOST OTHER COMPUTERS NEW! MX80 40, 80, 132 columns LIST §&4& TX 80 w/Graphics list jjasr Apple Controller & Card & Cable OUR PRICE CALL list £PKT Most reliable small printers ever sold! Uses standard printed paper. Graphics option transfers screen image directly to paper. $798 IF A ATARI MAKES IT, WE SELL IT Assembler/Editor 45 Atari 400 Computer 439 Atari 820 Printer 429 Atari 810 Disk Drive 499 Atari 410 Program Recorder 69 Atari 16K RAM Module 149 Atari Basic ROM 45 Atari Visicalc 180 Basketball 30 Video Easel 30 Super Breakout 30 Music Composer 45 Computer Chess 30 Star Raiders 39 3D Tic-Tac-Toe 30 850 Interface 169 825 Printer 795 PRINTERS, MONITORS, DISCS Anadex DP8000 850 Anadex DP8000AP 850 Color Monitor 375 Daisy Wheel Printer 1795 MPI 88T 595 NEC Spinwriter #5510 2595 Paper Tiger 445G w/Graphics 725 Paper Tiger 460 w/Graphics 1 195 Silentype w/interface Cd 540 Sanyo 9" B&W 169 Sanyo 15" B&W 259 NEC Green Screen 12" 239 Dysan disks (pkg. 10) 50 Memorex disks (pkg. 10) 40 Opus disks (pkg. 10) 35 Televideo 912C 699 Televideo 920C 749 Verbatim disks (pkg. 10) 30 LEEDEX VIDEO 100 1 2" Black & White $11 9 jfe MONTHLY jfc ^ SPECIALS ^ CENTRONICS 737 $737 cable extra V/SA % TO ORDER: Phone orders invited using Visa. Mastercard. or bank wire transfers, Visa & MC credit card service charge of >■'%. Mail orders may send charge card number (include expiration date), cashiers check, money order, or personal check (allow 10 business days for checks to clear). Please include phone number. Include 3% (S5.00 minimum) shipping, handling, and insurance in USA. Shipments within Calif, add 6% sales Tax. Foreign orders include 1% handling — shipped freight collect. Foreign orders over S1000 allow 6 weeks extra and include S25 license fee. All equipment is in factory cartons with the manufactures warranty. Equipment is subject to price change and availability. We ship the same day on most orders. No C.O.D.s or P.O.s accepted. Retail store prices differ from mail order prices. (714) 579-0330 • MAIL TO: 1251 broadway, el cajon, ca. 92021 DISK with CONTROLLER NEW DOS 3.3 $535 without . . . $446 Nearly Everything for Apple ;ci PP iG @ ][ i6K computer APPLE II 48K $1199 WE WILL BEAT ANY ADVERTISED PRICES ON MOST ITEMS IF MERCHANDISE IN STOCK APPLE SOFTWARE ALS Smarterm 324 Adventure by Microsoft 29 Apple Bowl "19 Apple Stellar Invaders 19 Assembler/Disassembler 69 Applebug Debugger 29 AppleGraph & Plot Sys 59 Applepost Mailing List Sys 44 Applesoft Cassette Demos 29 Applesoft Util. Prog. — Hayden 29 Applewriter Word Processor 65 Asteroids in Space 19 Autostart ROM Pkg 59 Battleship Commander 19 Bill Budges Space Game Album 39 Bill Budges 3-D Graphics/Tool 39 Bill Budges Trilogy of Games 29 Cashier Retail Mgmt. Sys 199 Checkbook Cassette 19 Contrib. Vols. 1-5 w/man 29 Controller Bus. Pkg 514 Cosmos Mission/Disk 25 CCA Data Mgmt. Sftwe 84 3-D Animation Pack 55 Desktop Plan Sftwe 79 DOS Tool Kit 65 DOS 3.3 Upgrade 49 Dow Jones Portfolio Evaluator 45 Fastgammon 23 Forth II by Softape 45 Fortran for Language Sys 159 Head-on 25 Integer Basic Cassette Demos 29 Lazer Systems Lower Case + Plus . . 59 Microsoft 16K Ramcard 179 PASCAL Language Sys 459 Sargon II Chess Game disk 34 Shell Games 29 Single Disk Copy Routines 35 Space Invader 25 Star Cruiser 24 Stellar Trek 23 Sub-Logic FS-1 Fit. Sim./disk 34 Tax Planner 99 The Correspondent 35 Tranquility Base 24 Visicalc by Personal Sftwe 119 Complete Peachtree Business Package for Apple AND MUCH MORE . . . call 1-800-854-2833 PHONE ORDERS MON. - SAT. 8 to 6 P.S.T. Circle 57 on inquiry card. APPLE COMPUTER INTERFACE CARDS HiSpeed Serial Int. Cd 155 Applesoft II Firmware Cd 149 Centronics Interface Cd 179 Apple Clock/Calendar Cd. by Mtn. Comp 225 Comm. Cd. & DB25 Cable 179 Integer Basic Firmware Cd 149 Parallel Printer Cd 139 CCS Parallel Print Cd. 7720A 155 ROMPLUS w/keyboard filter 165 ROMPLUS (keyboard filter extra) ... 159 SSM AIO Serial/Parallel I/O Assembled & Tested 189 Serial Interface Cd 139 CCS Asynchronous 7710A 139 ACCESSORIES Apple Joystick 47 ABT Numer. Input Keyboard A or B 114 A/D D/A Board by Mtn. Comp 319 Arith. Processor 781 1 A or B 339 Clear Cover for Apple Computer 25 COPYROM by Mtn. Comp 51 Corvus 10MByte Disk w/pwr. supp. 4395 Dan Paymar L.C. Kit 1 or 2 59 Extender Board 27 GPIB by CCS model 7490A 259 Graphics Input Tablet 649 Hayes Micromodem' 319 Introl X-10 Remote Control Sys 239 Introl X-10 Controller Only 169 M&R Sup-R-Term 80 column board . 329 Microsoft Z-80 Soft Card 295 Novation Cat Modem 159 Programmable Timer CCS 7440A ... 159 Prototyping Hobby Card 22 ROMWRITER by Mtn. Comp 149 Speechlink 2000/64 Word Vocab. ... 215 SuperTalker Speech Synthesizer. . . . 239 Symtec Light Pen 214 Versa-Writer Digitizer Drawing System 209 Videx Videoterm 319 START TRANSPORT (error EXIT J WAIT FOR CHANGE IN TAPE OUTPUT DATA START TIMER STORE DATA IN BUFFER SKIP TO IRG (ERROR EXIT ) YES EMPTY BUFFER (ERROR EXIT J YES ( EXIT ) (error exit J TRANSFER DATA FROM BUFFER TO DBBOUT Figure 8: Flowchart of the READ command sequence. Text continued from page 82: used to signal both the initial cell transition and the mid-cell transition, generating an internal interrupt every 208 /is. Thus, a byte is written every sixteen timer interrupts, or 3.3 ms. If nothing unusual happens during the operation, it returns a Good- Completion result code (hexadecimal 00) to the host. If an error occurs, the 8741A mini- cassette controller provides error wrap-up facilities, protecting the in- formation on the tape from being cor- rupted. For example, if the clear leader of the tape is found during a write operation, the transport is halted immediately. Another error results from the processor being late in supplying data to the controller, causing a data-underrun error and aborting the data transfer. A 450 ms IRG is then written onto the tape before the transport is halted. READ Command The READ command provides er- ror checking similar to the WRITE command. Once the READ command is issued by the microprocessor, the controller checks for cassette presence and starts the transport. The data output from the transport is then ex- amined and decoded continuously. This function is shown in the flowcharts of figures 8 and 9. The first character must be a Sync, or the 86 April 1981 © BYTE Publications lnc Introducing quality print at matrix speed. For only $1295! Until now, word processing output was a slow, expensive proposition. You could pay thousands for a slow, letter- quality character printer. Or give up print quality for matrix speed and price. But that was before Paper Tiger™ 460 offered you a better choice. The new Paper Tiger 460 is the first matrix printer with high-density dot matrix characters plus high speed. At a low price. The secret? A unique nine-wire, stag- gered matrix head provides overlap- ping dots in both horizontal and vertical planes. The result is dense, high-quality characters you'll be proud to show off. What's more, Paper Tiger 460 gives you a combination of fea- tures simply not available on any other printer, at any price. Like bi-directional, logic-seeking print- ing at speeds in excess of 1 50 characters per second. Micro- , processor electronics, with built-in diag- nostics and self-test. Proportional spacing. Automatic text justification. DotPlot™ high Integral Data Systems stands re£ performance printers ideally su printer, the IDS 460, offers feat Automatic proportional spacing processing systems, plus the cap resolution of 84 by 84 dots per Paper Tiger 460 Print Sample resolution graphics option. RS232 and paral- lel interfaces. And more. But its most important feature is high relia- bility. Paper Tiger 460 is designed to be tough and dependable. It has rugged, stepper-motor head and paper drives. A new rugged ballistic-type print head. Circle 58 on inquiry card. And its simple, chassis-mounted cartridge ribbon lasts up to four times longer than cassette or spool ribbons. Paper Tiger 460 is the one printer that gives your Apple, 1 TRS-80,*or other small business computer both data processing and word process- ing output. At a price you can afford. Get your paws on Paper Tiger 460, and join the tens of thousands of satisfied Integral Data Systems users. For the name of the Paper Tiger dealer nearest you. Call us toll-free-. 800-258-1386. (In New Hamp- shire, Alaska, and Hawaii, call (603) 673-9100.) Or, write for complete specifications. Integral Data Systems Inc., Milford, New Hampshire 03055. •Suggested single-unit U.S. retail price. t Apple is a trademark of Apple Computer Inc. tTRS-80 is a trademark of Radio Shack, a division of Tandy Corp. MODEL III DRIVES Save up to 34% compared to Radio Shack Now, add mini-disk drives to your TRS-80 Model III'" and get FREE INSTALLATION. Fully compatible with Radio Shack's operating system TRSDOS. • One, two, three, four drive configurations • 134K to over 1 Meg of storage • 40 track and 80 track available • 90 day warranty, 100% parts and labor • Extended warranty available Complete upgrade includes one mini-disk drive, power supply, controller, and mounting hardware. IMMEDIATE DELIVERY. OUR RADIO PRICE SHACK SAVINGS Complete one drive kit $599. $849. 29% Additional internal drive 265. 399. 34% External drive 340. 499. 32% 80 track drives (incl. patch) add 250. ea N/A 16K memory (required to use drives) 49. 119. 59% Model III 32K w/ VR Data Drives 1812. 2380. 24% Add-on SuperBrain Drives AVAILABLE ONLY FROM VR DATA! Increase the storage capacity of your SuperBrain'" to 700K with two extra 40 track drives, or over I Meg with QD drives. • Fully compatible with SuperBrain operating system • Fully compatible with all SuperBrain drives • Easy plug-in installation • Includes patch program • 90 day warranty, 100% parts and labor • Extended warranty available Complete two drive kit (incls. cable and patch) 789. QD drives 1339. If two extra drives aren't enough try our 6.3 Meg Winchester Assembly (complete with software patch) $3495. SuperBrain Parallel Printer Port Available only from VR Data! Now, you can add a parallel printer port to your SuperBrain and use Centronics - compatible parallel printers. • designed exclusively for the SuperBrain by VR Data • easy, plug-in installation • 90 day warranty, 100% parts & labor • complete $99.95 VR Data, a manufacturer of innovative computer products, is known world-wide for quality, dependability and prompt, personal service since 1972. To order call toll free (800) 345-8102, or (215) 461-5300 in PA. 5)aJa 777 Henderson Blvd. ■ Folcroft, PA 19032. f RD INT J STORE DATA OUTPUT BIT IN REGISTER RELOAD AND START TIMER ( EXIT ) Figure 9: Flowchart of the READ interrupt routine. controller will abort the read opera- tion, return a Bad-First-Sync result code (hexadecimal 42), and advance to the next IRG of the tape. If the Sync character is correct, succeeding characters are read into an internal 30-character FIFO (first-in, first-out) buffer, allowing the processor over 99 ms of service latency before a data- overrun condition occurs. Whenever the DBBOUT register is empty, data is transferred to it from the FIFO buf- fer. This continues until an IRG is en- countered, at which point the transport is stopped. The controller then tests the last character. If it is a Sync, the controller compares the ac- f SKIP J GET BLKCNT YES SELECT FORWARD AND START TRANSPORT NO SELECT REWIND AND START TRANSPORT YES SELECT 3 IPS SPEED NO /BLKCNT\ YES >8 P SELECT 5 IPS SPEED SKIP A BLOCK DECREMENT BLKCNT NO STOP TRANSPORT Terror exit J SKIP A BLOCK DECREMENT BLKCNT STOP TRANSPORT ( EX ' T ) STOP TRANSPORT C EXIT ) Figure 10: Flowchart of the SKIP command sequence. 88 April 1981 © BYTE Publications Inc Meet the Tiger with, a biaaer bite. Introducing the remarkable 132-column Paper Tiger™ 560. The first full-width matrix printer to give you fully formed characters for a low $1695.* The new 560 features a staggered nine- wire ballistic type print head that overlaps dots in both horizontal and vertical planes. It bi-directionally prints up to 150 dense, text quality characters per second. The 560 also features a reliable cartridge ribbon that lasts up to four times as long presents a breakthrough in matriK printim ering the user excellent print quality wit; ce of a matriK printer. Employing a uniq red column" head manufactured by Integr creates high quality printouts by overla Paper Tiger 560 Print Sample as spool and cassette ribbons, separate heavy-duty stepper motors to drive the print head and advance the paper, plus true tractor feed. And famous Paper Tiger performance comes with every new 560. Like fixed or proportionately spaced text, programmable tabbing and business forms control, auto- matic text justification, print formats to 220 columns, parallel and serial interfaces, self- diagnostics, and more. All inside the most compact printer of its kind. Need more stripes? Dotplot ,™ our high- resolution raster graphics package, is stan- dard on every 560. For data processing, word processing and small business applications, this is your Tiger. The business-sized Paper Tiger™ 560. It's a Tiger you can count on. Call TOLL FREE 800-258-1386 (In New Hampshire, Alaska and Hawaii, call 603-673-9100.) Or write: Integral Data Systems, Inc. , Milford, NH 03055. Tiger 560 ■Lw) jlntegral Data Systems, Inc. Circle 59 on inquiry card. *Suggested U.S. retail price. SELECT REWIND AND START TRANSPORT WAIT 50ms STOP TRANSPORT C exit ) ( EXIT ) Figure 11: Flowchart of the REWIND command sequence. cumulated internal checksum to the block's checksum, the last character of the block. If they match, a Good- Completion result code (hexadecimal 00) is returned to the host. Otherwise, the appropriate error-result code is returned (ie: Bad Sync2 or Checksum error). The READ command also checks continuously for the End-of- Tape (EOT) clear leader and returns the appropriate error code if it is found before the read operation is complete. SKIP Command The SKIP command (see figure 10) allows the host to skip up to 127 blocks forward or backward. Im- mediately following the command byte, the controller expects an 8-bit signed-magnitude byte specifying the number of blocks to skip. The most significant bit of this byte selects the direction of the skip (0 = forward, l = reverse). SKIP provides two search speeds in the forward direc- tion. If the number of blocks to skip is greater than 8, the controller uses fast forward (5 ips) until it is within 8 blocks of the desired location, then switches to the normal read speed of 3 ips to allow accurate placement of the tape. The reverse SKIP uses only the re- wind speed (15 ips). Like the READ and WRITE commands, SKIP also checks for EOT and Beginning-of- Tape (BOT) depending upon the tape's direction, returning an error code if either is encountered before the specified number of blocks have been skipped. REWIND Command The REWIND command routine, figure 11, sets the transport to fast re- wind of 15 ips and waits until the clear-leader status input of the transport is active for more than 50 ms. (There is a hole at each end of the tape. It is guaranteed not to cause the clear-leader input to be active for more than 50 ms.) Once the clear leader is found, the CM-600 is stopped and a Good-Completion result code is loaded into DBBOUT. ABORT Command The final command, ABORT, is not a stand-alone command like the From Ballet on Broadway to Billiards m Dallas... . . . people are finding unique ways to use the Powerful SciTronics REMOTE CONTROLLER Whether it's the intricate fighting for a Broadway Ballet or the sim- ple remote lighting of pool tables in a Dallas billiards hall, people are finding out SciTronics Remote Controller can meet their needs. Here's Why: Controls 256 BSR remote switches— not just 16 Hardware driven— requires minimum software No ultrasonic link— prevents erratic operation No BSR command module necessary Real Time Clock gives Remote Controller an added dimension! Real Time Clocks are now available to make your remote controller even more powerful. The RTC feature allows for energy consumption scheduling, event scheduling and much more. Your imagination is your only limitation when it comes to the ways which this RC/RTC combination can be used. Real Time Clocks feature: Lithium battery back-up Crystal controlled accuracy (.002%) Clock generates interrupts (seconds, minutes, hours) for foreground/background operation Complete software in BASIC to Set and Read clock etc) $159. $159. $184. $269. $129. S-100 CONTROLLER BOARD S-100 REAL TIME CLOCK BOARD ENCASED CONTROLLER (TRS-80, Apple II etc.) ENCASED CONTROLLER & REAL TIME CLOCK (TRS-80, Apple II APPLE II CLOCK BOARD send check SciTronics Inc. or money 523 s. Clewell St., P.O. BOX 5344 order,0: Bethlehem, PA 18015 (215) 868-7220 Please list system with which you plan to use peripheral. Master Charge and Visa accepted. PA residents add sales tax. COD's accepted. 90 April 1981 © BYTE Publications Inc Circle 60 on inquiry card. Big Savings for SS-50 Bus Computerists Save $140! LFD-400'Mini-Disk System $459.95 The choice of knowledgeable 680X computerists since 1977 • Proven clock-data separation circuitry and other superior design features • Reliable hard- sector diskette formatting • Stores up to 102 Kbytes of formatted data on 40 tracks • Comes complete with 4-drive controller, drive assembly, 6800 or 6809 ROM disk operating system, interconnecting cable and compre- hensive users manual • Add-on drives cost only $399.95 each. Circle 363 REGULAR $599.95 SBC/^Single-Board Computer ^ ' $139.95 A computer or a fully compatible SS- 50 bus MPU card • Interchangeable 6802 or 6809 processor • Extendable 1-Kbyte ROM monitor • Parallel and serial I/O ports — selectable, full-range bit rate generator for serial I/O • Extendable addressing • On-card 1-Kbyte RAM • Provision for additional C~.,„ EPROM • On-card voltage regulator circuits circle 364 O Swca^r and PET )ERRV POUftMEUJt Ai»... cowwurmn mRficrroRT COMPUT8R CLUBS: WMO H€XDS THEMt onComptrtlngTM Subscription Dept. P.O. Box 307. Martinsville, NJ 08836 DOMESTIC subscription rate: U.S. 1 yr. (4 issues) @ $8.50 Canada & Mexico, 1 yr (4 issues) @ S 10.00 FOREIGN (to expedite service, please remit in U.S. funds drawn on a U.S. bank ) Europe (and all other countries, except above). 1 yr. @ C 12.00 — surface delivery. ! 1 Bill Visa . Bill Master Charge Bill me (North America only) Card Number Expiration Signature Name (please print) Street/ Apartment Number City State/Province/Country Code Please allow 6-8 weeks for processing. 96 April 1981 © BYTE Publications Inc 1.1 1 m ■ ' v 4 1 ill 1 W^^^^KM L'''1h 1 m *fl^|F kfifl^V "And in conclusion, 111 only use my exceptional powers for the good of mankind." "That's a vow all we Vector 3005s make. And it's not one we make lightly. "After all, being the only product on the market with a Vector 3 terminal, a 5%" floppy, and a 5K" Winchester rigid disk drive that provides 5 megabytes of storage is quite a responsibility. It used to take 20 floppies to give you that kind of capacity. "Our powers don't stop there, however. Each 3005 also comes with a 32-bit error-correcting code — the first time sophisticated IBM-style technology has been available on a small business system. This lets us detect and correct errors, and almost completely eliminates data loss on disks due to dirt, wear, or damage. "All this makes us pretty awesome, all right. But there's more. When coupled with Vector's MEM0RITE III and EXECUPLAN software packages, we give you a 30,000 word dictionary, the ability to create your own phrase library, a teaching manual right on the screen, pass word security, plus a host of other word processing capabili- ties as well as financial planning, forecasting and basic accounting. "And we're reliable. Our powers won't diminish, our abili- ties won't fade, and dedication to mankind won't weaken. "For more information and your nearest dealer, call Vector at 800-423-5857. In California, call 800-382-3367. Or write to them at 31364 Via Colinas, Westlake Village, CA 91362. "Thank you all for coming today. And I hope we'll have the chance to do business together in the future!' VECTOR GRAPHIC INC. COMPUTERS FOR THE ADVANCEMENT OF SOCIETY. Circle 66 on inquiry card. Technical Forum MicroShakespeare Revisited or Kilobard Andrew Kalnik, 3201 Wamath Dr, Charlotte NC 28210 William Shakespeare would have made a first-rate computer analyst. He had all the qualifications: superb powers of observation, capacity to deal with complex problems, imagination, and a fair ability to express himself. Looking at his writings, you can easily recognize the vocabulary of a systems consultant making his pitch to land an installation contract. Presented in a conference room against a backdrop of easel charts, with gold- stamped proposal binders on the broad walnut table, some of his phrases would be right in place: "...I'll teach you how to flow..." (The Tempest, Act II, scene i) "What is written shall be executed..." (Titus Andronicus, Act V, scene ii) "I will execute, and it shall go hard, but I will better the instruction..." (Merchant of Venice, Act III, scene i) "...Our interpreter does it well..." (All's Well That Ends Well, Act IV, scene iii) From other lines, you can feel the sympathy the Pro- grammer of Avon would give wretches like you and me sentenced to a debugging session: "O hateful error, melancholy's child Why dost thou show to the apt thoughts of man The things that are not? O, error, soon conceived Thou never comest into a happy birth..." (Julius Caesar, Act V, scene iii) Here's another short quiz to test how well you can match Master Will's golden words against the shiny silicon jargon of our art. (Try your hand at the other quiz in the April 1980 BYTE, page 104.) What we've done is to make free translations from Shakespearean phrases into terms familiar in computing. Simply match the letter of the most pertinent modern phrase against the quotations. No prizes, just the satisfac- tion of puzzling out the answers. The answers and ratings are on page 184. [Editor's note: Each of the items 1 thru 20 will match to one of the answers "a" thru "t, " so read through all the answers before you try to make a match. ...GW] 1. ( 2. ( 3. ( ) 4. ( 5. ( ) ( ) 7. ( We'll evaluate a. "And that your purpose, crashed the and put on a whole form... program!" Troilus and Cressida, Act III, scene iii ...an adder did o. "We'll have it... the function A Midsum- graphed on mer Night's screen in a Dream, few seconds." Ill/ii That one error :. "I wish I could fills him with check the reg- faults. ister flags." Two Gentlemen of Verona, V/iv ...shall run in a d. "There isn't new channel much time to fair and convert the evenly... analog readings I Henry IV, between inter- I/i rupts." ...unpleasantest 2. "Put a scope on words that ever it to check blotted paper... those big The Merchant input spikes." of Venice, Ill/ii ...inferreth : . "With the new arguments of I/O board, it mighty should just strength... perk right Ill Henry VI, along." V/ii ...the minute of g. "That frosts me their plot is — we're not get- almost come... ting any output The Tempest, from those IV/i ANDs." 98 April 1981 © BYTE Publications toe C ^Pascal Efficiency^rortability Flexibility^otrong Typing Now you don't have to compromise! Whitesmiths Ltd. now offers portable language development systems for four families of computers. Approximately one thousand installations use our software. We support complete versions of both C and Pascal, as compilers and cross- compilers. You get C automatically when you license Pascal, and you get native support with each cross-compiler. Test the software on your VAX before burning PROMs for your 68000 or 8080. Whitesmiths Ltd. offers a variety of licensing arrangements, the simplest being a binary license for use on a single CPU. The full source code is avail- able with internal documentation. Maintenance, training and sublicensing rights may also be obtained. Call or write for more information. Source Operating Systems 8080 /Z80 Target ft LSI-ll /PDP-11 lachines VAX-11 M68000 8080/Z80 CP/M C: $630 Pascal: $880 # # * LSI-ll/ PDP-11: Idris, Unix, RT11, RSX-ll/M, RSTS/E, IAS C: $1130 Pascal: $1380 C: $630 Pascal: $880 * C: $1130 Pascal: $1380 VAX-11 Unix/V32 VMS C: $1130 Pascal: $1380 * C: $630 Pascal: $880 C: $1130 Pascal: $1380 M68000 VERSAdos * * * C: $630 Pascal: $880 Idris is a trademark of Whitesmiths, Ltd, ■ Unix is a trademark of Bull Laboratories ■ CP/M is a trademark of Digital Research Company ■ VMS, RSX-ll/M, RSTS/E, LSI-ll, VAX, arc trademarks of Digital Equipment Corporation ■ VERSAdos is a trademark of Motorola Corporation * Special Order Protect .your software \\r Tl investment. ♦ 1 y t Whitesmiths, Ltd RO.Box 1132 Ansonia Station New York, NX10023 (212) 7994200 Circle 67 on inquiry card. BYTE April 1981 99 Technical Forum. 8. ( ) This fierce abridgement hath to it cir- cumstantial branches. Cymbeline, V/v 9. ( ) Look, what thy memory cannot contain/ Com- mit to these waste blanks. Sonnet Ixxvii 10. ( ) ...full char- actered, lasting memory... Sonnet cxxii 11. ( ) ...the very cipher of a function... Measure for Measure, Il/ii "We regret to inform you that we can no longer supply replacement parts for your system." NOP "It was in ac- cumulator A." "Looks like you're getting a hard-copy memory dump." Save on Calculators Model New Hp-41 CV 2.2K bytes, 4 mem. modules buill-in, slanted keyboard System One, HP41CV & Card Reader System Two. HP41CV-Card Reader & Printer Card reader (or4!C/41CV Pnnterfor4IC/41CV HP-41 Crew price Quad Ram lo upgrade Ihe HP41C to 2.2K bytes leaving 3 ports...PlLigs into the 41i Optical Wandfor41C/41CV Memory Modules for 4! C41CV HP-34C Scientific HP-38C Bus /R.E. HP-33C Scientific HP-32E Adv. Scientific HP 37E Bus Calc. HP-67 Programmable Sci. HP 97 Prog. Printer Sci. HP-85 Computer New HP-83 Computer, similar to HP-B5 without printer & cassette HEWLETT PACKARD 325Q.00 2495.00 2250.00 1795.00 One year guarantee by HP on all calcs, 9D days on computers All units complete. Texas Instruments <9 Ask about special rebate on some Tl calculators and free software on TI-59. Speak and Read S469.95 199.95 39.95 49.95 159.95 18995 35.95 TJ 50 35.95 Speak and Spell 58.95 TT-99/4 Computer Console TI-59 TI-58C TI-57 PC 10DC TI-5230 printer (was S495.) Speak and Math Language Tutor fSpeaks) Language Teacher Invest Analyst Bus Analyst II Tl Programmer Tl 5040 Printer Ask about the new line of Tl pi; printers at new low casts. 74.95 67.95 129.95 72.95 48.95 43.95 4895 74.95 in paper SPECIALS APPLE II and APPLE III w Huge inventory of Apple II computers. 16K-32K-48K. Disk drives, monitors. 80 column card. Dow Jones & Quote Reporter. Pascal-Fortran— DOS 3.3, etc. You name it.. .we've got it at super low prices. Immediate delivery on Apple IN com- puters %K and 12BK systems. Call usl Apple II personal computer SCM Typewnu Computers at unbeatable prices Texas Instruments Tr 99/4 console computer Atari 800 16K computer console Atari TV Game Mattel Intellivision TV Game Mattel Race Horse Analyzer Sony Walkman TPS L2 Centronics printer PI for Apple and Radio Shack computers Was $495.00. Craig Translator M 100 320 models Seiko watches • Royal • Victor • Canon ■ Sharp • Casio and n S469.95 759.95 139.95 229.95 99.95 169.95 189.95 99.95 VISA' Prices f.n.b. L.A. Minimum freight & handling charge— S4.95. In CA, add 6% sales tax. Goods subject to availability. We'll beat any advertised price if competitor has goods on hand CallMon-Sat 7AM-6PM Outside CA, toll free 800-421-8045 Inside CA, toll free 800-252-2153 Olympic SAies com pah* inc. 216 South (Word Ave • P.O. Box 74545 • Los Angeles, CA 90004 ■ (213) 381-3911 Order Desk (213) 739-1130 ■ Customer Service (213) 739-1100 • Telen 67-3477 12. ( ) ...Would I were 1. assured of my condition... King Lear, IV/vii 13. ( ) ...Is it ended m. then...? Coriolanus, IV/iii 14. ( ) ...The gates n. made fast! Brother, I like not this. Ill Henry VI, IV/vii 15. ( ) O'erbearing o. interruption... King John, Ill/iv 16. ( ) ...mark the high p. noises... King Lear, Ill/vi 17. ( ) What should q. that alpha- betical position portend? Twelfth Night, II/v 18. ( ) Thou hast r. caused printing to be used... Ill Henry VI, IV/ii 19. ( ) What I can do s. can do no hurt to try... All's Well That Ends Well, Il/i 20. ( ) If it were done t. when 'tis done, then 'twere well/ It were done quickly... Macbeth, I/vii See answers on page 184. ■ "If you have no more memory left, you store everything on a scratch disk." "Let's work up a high-level flowchart." "We can't be any worse off.' "It seems you can call a macro that in- verts a 99 by 99 matrix." "It's un- maskable." "That IF-THEN- ELSE decision sequence cut the program down by at least 40%." "Are we at step 9999?" "ROM with complete ASCII set." "Can you tell me what this string is doing in position FFCA?" 100 April 1981 © BYTE Publications Inc Circle 68 on inquiry card. Software Professionals At General Electric we're using computers in ways no one thought of before. If you are looking for exciting technical chal- lenges coupled with excellent growth oppor- tunities join General Electric's Space Sys- tems Division. Help us develop large scale, distributed, information processing systems requiring innovative design approaches. You Entry level and Sr. positions available for will be working in the following Data Proces- sing Environments : 3033 ■ JES2 3081 ■ ACF/NCP VAX 11/780 ■ ADA BAS MVS MVS Systems Programmers Perform SYSGENs, maintain and tune MVS. Select and install program products. Develop MVS enhancements, H/W-S/W interfaces, and 3705 telecommunications ap- plications. Math Analysts Perform modeling for simulation of complex command and control systems. Solve opera- tional research problems and develop algori- thms in systems and vehicle flight dynamics and orbit mechanics. Develop computer pro- grams to generate study data to aid analysis and trade-offs. Computer Systems Architects Responsible for requirements analysis in the design of large scale Computer Systems to support on-line information management ap- plications. Duties include selection and speci- fications of: • Computer Hardware • Operating Systems • Data Management Systems • Telecommunications Systems Data Base Designers/ Administrators Perform data base design-administration and implementation tasks for large scale data systems using state-of-the-art data base man- agement tools. Analyze data base require- ments. Design and select file structures, access methods, and data management techniques. Install, maintain and tune vendor supplied Data Base Management packages. Provide Data Base support and technical interface for Data Base definition, design, query and update utilities. Data Base Analysts Responsible for data requirements analysis and subsequent selection of appropriate data management approaches including Data Base Management Systems evaluations. Programmer/ Analysts Develop design approaches and implement state-of-the-art, high technology programs. Knowledge of structured implementation en- vironment with related documentations and design reviews a plus. For immediate consideration, please forward your resume indicating position of interest to: Mr. William E. Sarno, Dept. VF 31-D, General Electric Space Systems Division, Valley Forge Space Center, Goddard Blvd., King of Prussia, PA 19406. Applying computers to make our most important product: Progress GENERAL ELECTRIC GE takes pride in being an equal opportunity employer, m/f Programming the Game of Go Jonathan K Millen 661 Main St Concord MA 01742 Go is a board game. Like chess, it is a game of pure skill; moreover, a con- siderable body of literature has been devoted to it. Go was invented in China around 2000 BC. Since its in- troduction into Japan around 700 AD, it has flourished there to the ex- tent that the most accomplished masters of the game are now Japanese. However, the game has spread world-wide. In the United States, one can find Go clubs in the vicinity of large cities and univer- sities, and most large bookstores have at least one substantial book on the game. Go is played on a 19 by 19 square grid having black spots on nine in- tersections, as illustrated in figure 1. The traditional board, called a Go Ban, is a wooden block about 17 inches square and several inches thick, with four short feet. It stands alone as a table at just the correct height for players sitting on floor cushions. One player has a supply of black stones; the other, white stones. The stones are disks about the same size as the grid spacing; they are approx- imately three-eighths of an inch thick in the middle and almost sharp around the edge. The black stones traditionally are made of slate, and the white stones of clam shell. Players move alternately, each placing a stone on the point of in- tersection of a pair of grid lines. The object of the game is to enclose the most area, measured by the number of unoccupied points enclosed by stones of a given color. A point is enclosed by, say, black, if no path along the grid from the point runs in- to a white stone. Figure 2 shows some enclosed areas. Note that the edge of the board can form one boundary of an area. A player can increase his area by capturing the opponent's stones. Stones are captured a connected group at a time. A set of stones forms a connected group if there are paths along the grid from any stone to any other stone in the set, such that all points on the path are occupied by stones in the set. This criterion is easy to visualize because the stones, being as large as the grid spacing, actually touch along paths of connection. The phrase "connected group" also im- plies that the stones in the group are all of the same color, and that the group is not merely a part of some larger connected group. A group of stones is captured when it has no liberties. A liberty of a con- nected group is an unoccupied point adjacent (vertically or horizontally) to a stone in the group. If a group has just one liberty, the opponent may capture it by placing one of his stones on the liberty. The opponent then picks up the captured stones and keeps them as prisoners. At the end of the game, a player's point count of area is augmented by the number of prisoners he has captured. Figure 3 shows a group having one liberty. The game ends when both players pass consecutively, because they both see no further advantage in playing more stones. Usually, when this hap- pens, there are white stones within areas enclosed by black, and vice ver- sa. These stones have been given up because the owner can predict that they will be captured. They are removed as prisoners at the end of the game before counting the score. The remaining rules are tech- nicalities. Two that have a significant effect on the game, concerning "ko" and "suicide," will be mentioned later on. The rest involve details of ending the game and scoring, and are rarely invoked. A Go-Playing Program A Go opponent, called Wally, was programmed on a KIM-1 within its approximately 1 K bytes of memory. Wally's algorithm is based on essen- tially two capabilities: finding the liberties of a connected group, and matching a few common patterns. Moves take less than a second. A 15 by 15 board was used because 102 April 1981 © BYTE Publications Inc Circle 69 on inquiry card. comments: WCompared to the brands I've used before,Verbatim Datalife is the best yet! ?? Sandy Tied em an Las Vegas, NV WNew Verbatim helped eliminate I O errors on my Apple. W Richard Adams Ft. Walton Beach, FL WI would prefer Verbatim Datalife over any brand I've ever used.?? SkipPiltz Overland Park, KS WMy experience with Verbatim diskettes has been excellent. I've used several boxes over the past few months and they've all been error-free. f$ Robert Roeder Las Vegas, NV WMuch stronger, better centering. A definite im- provement. 99 Leroy LaBalle Marrero, LA Wit has worked perfectly everytime!?? Richard Ruth Shippr WI like the thicker pro- tective cover. 99 David Hendel Lititz, PA WGreat! I have had no problems!?? Timothy Roscoe Mechanicsburg, PA WSo far my Verbatim disks have been performing flaw- lessly. Not always so with other disks. 99 Chris Otis Hoffman Estates, IL WRuns quieter in the disk drive. JJ Richard Cannova Los Angeles, CA W Verbatim disks are super. They're our standard for quality.?? Bob Mills Mission, KS WAnything that prolongs the life of a diskette is a plus. Thank you Verbatim for an excellent improvement.?? Steve Toth Piscataway, NJ W Of the 130-plus Verbatim disks I have, I'm not aware of any problems. I'm sure the improvements will give your disks an even longer life.?? Gerald Janas Warren, MI WFANTASTIC. Not a single more reliable than what I had been using.?? Gary Sandler iS PlayaDelRey,CA^\ WVerbatim is much more reliable. I wouldn't trust anything else.?? Howard Chin Pomona, CA W Thank you for the im- provements. Just another reason why 111 always use Verbatim.?? James Hassle r Cheyenne, WY We introduced Verbatim Datalife mere months ago. And it's already playing to rave reviews like these. But don't take anybody else's word for it. Try it your- self, and see if you don't agree it's the best media you've ever tried. For the name of your nearest Verbatim dealer, call (800) 538-1793, in California call (408] 737-7771 collect. \ferhgtim IH We play it back, Verbatim! ■ Figure 1: The Go board. Players move alternately, placing stones on the points of in- tersection of the lines, rather than in the spaces. The nine dots are handicap-stone loca- tions. The line spacing is about 2.2 cm (seven-eighths of an inch). MARK GORDON COMPUTERS DIVISION OF MARK GORDON ASSOCIATES, INC. P.O. Box 77, Chartestown, MA 02129 (617) 491-7505 COMPUTERS Atari 800W 16K 799.00 4K Model III 599.00 Model-ll 64K System 3499.00 16K Model III 879.00 DISK DRIVES 40 Track 5'/. inch drive 314.00 80 Track 5V. 544.00 4 Disk Drive Cable 39.00 PRINTERS Centronics 730 599.00 Epson MX80B Call for price Epson MX70 Call for price Centronics 737 849.00 Okidata Microline 83 999.00 Okidata Microline 82 729.00 Integral Data 440G 999.00 NEC 55 1 w-tractor 2679.00 Okidata Microline 80 499.00 Diablo 630 2495.00 MISC HARDWARE Expansion int TRS-80(Ok) 269.00 Novation D-Cat Modem 166.00 1 6K Memory Kit 41.99 Leedex Monitor 1 1 9.00 Leedex 100Q 139.00 Printer Cable for above 49.00 ISO-2 Isolator 54.00 AC LINE FILTER 24.00 STORAGE MEDIA Scotch-box 10-5% 27.00 Memorex-box 10-5'/< 22.00 Plastic Storage Box 5.00 OPERATING SYSTEMS NEWDOS by APPARAT INC 49.00 NEWDOS+ by APPARAT INC 99.00 MMS FORTH DISKETTE-PRIMER 79.95 NEWDOS 80 149.00 DISKETTE TRS-80» BUSINESS SOFTWARE FOR TRS-80 BY SBSG Free enhancements and upgrades to registered owners for the cost of media and mailing. 30 day free telephone support. User reference on request. Fully Interactive Accounting Package. General Ledger. Accounts Payable, Accounts Receivable and Payroll Report Generating Complete Package {requires 3 or 4 drives) S475.0O Individual Modules (requires 2 or 3 drives) S 125.00 Inventory I] (requires 2 or 3 drives) S99.00 Mailing List Name & Address II (requires 2 drives) ...SI 29.00 Intelligent Terminal System ST-80 III $150.00 The Electric Pencil from Michael Shrayer SI 50.00 File Management System S 49.00 FINE PRINT TRS-80 is a Tandy Corporation trademark. Use of above operating systems may require the use of Radio Shack TRS- DOS. Radio Shack equipment subject to the will and whim of Radio Shack. ORDERING INFORMATION We accept Visa and Mastercfiarge. We will ship C.O.D, cer- tified check, or money order only. There will be a 40 percent deposit on orders over $300.00. Massachusetts residents add 5 percent sales tax. To order call toll-free 1-800-343-5206 For information call 617-491-7505 The Company cannot be liable for pictorial or typographical Inaccuracies. The above prices do not Include shipping. Figure 2: Enclosed areas. Points marked x are in areas enclosed by one player or the other. The figure shows five black points and eight white points. Figure 3: A black group with exactly one liberty, marked x. If it is white's turn, he can capture the black group by placing a stone at x and removing the black group as his prisoners. it was convenient for addressing reasons to represent it internally within a single 256-byte page, using one byte per point. Although there would be room for a 16 by 16 board, a Go board ought to have a center point. Rows and columns were num- bered from 1 to F (in hexadecimal) so that the coordinates of a move could be entered on the KIM keyboard. When a move is entered, Wally responds with the coordinates of his move on the KIM display, and the complete board is also output on a video terminal. The display of a game in progress is shown in photo 1. Once the board representation and the input and output routines were set up, the first major component of the 104 April 1981 © BYTE Publications Inc Circle 70 on Inquiry card. Circle 71 on inquiry card. Multi-User UniFLEX is the first full capability multi-user operating system available for microprocessors. Designed for the 6809 and 68000, it offers its users a very friendly computing environment. After a user 'logs-in' with his user name and password, any of the system programs may be run at will. One user may run the text editor while another runs BASIC and still another runs the C compiler. Each user operates in his own system environment, unaware of other user activity. The total number of users is only restricted by the resources and efficiency of the hardware in use. The design of UniFLEX, with its hierarchical file system and device independent I/O, allows the creation of a variety of complex support programs. There is currently a wide variety of software available and under development. Included in this list is a Text Processing System for word processing functions, BASIC interpreter and precompiler for general programming and educational use, native C and Pascal compilers for more advanced programming, sort/merge for business applications, and a variety of debug packages. The standard system includes a text editor, assembler, and about forty utility programs. UniFLEX for 6809 is sold with a single CPU license and one years maintenance for $450.00. Additional yearly maintenance is available for $100.00. OEM licenses are also available. FLEX Multi-Tasking UniFLEX is a true multi-tasking operating system. Not only may several users run different programs, but one user may run several programs at a time. For example, a compilation of one file could be initiated while simultaneously making changes to another file using the text editor. New tasks are generated in the system by the 'fork' operation. Tasks may be run in the background or 'locked' in main memory to assist critical response times. Inter- task communication is also supported through the 'pipe' mechanism. UniFLEX is offered for the advanced microprocessor systems. FLEX, the industry standard for 6800 and 6809 systems, is offered for smaller, single user systems. A full line of FLEX support software and OEM licenses are also available. Box 2570, West Lafayette, IN 47906 (317) 463-2502 Telex 276143 "''UniFLEX and FLEX are trademarks of Technical Systems Consultants, Inc. program to be written was the routine that walks through a connected group of stones, marking the members of the group, and both marking and counting its liberties. Called COUNT, this routine is a variety of the maze-search algorithm. It was programmed recursively in machine language. What COUNT does for each board location it looks at is based on the "invariant assertion" that any point it looks at is one of the following: • a stone in the connected group • a liberty of the connected group • a stone of the other color adjacent to the connected group If it is looking at a stone in the group, it checks to see whether that stone has previously been marked. If not, it marks the stone and calls itself to repeat the same process, starting with each of the four locations north, east, south, and west of the present stone. Marking a stone or point, of course, means to set a particular bit in the byte corresponding to that point in the board representation. Other bits encode whether the point is ■J 2 1 234!«;i)IICDEf • - ♦ - II Q . . . 3 4 S 6 7 8 '. • • • . • t • t • . ...... I.M. 9 A 1 C D E F •••• . e o •••#0. Photo 1: A game in progress. Wally (the computer) is playing black, represented by the solid-looking crosshatches (§). The author is playing white, represented by Os. The computer uses a 15 by 15 board; the points of play are indicated by periods. In this game, black was given a nine-stone handicap. occupied and, if so, by what color stone. If COUNT is looking at an unoc- cupied point, it marks the point as a liberty and increments the count of liberties, unless the point has already been marked and counted. If COUNT is looking at a stone of the other color, it does nothing, and just returns. If a stone is on the edge, or first line, of the board, then one (or, in a corner, two) of its neighbors will be off the board. If COUNT is called for an off-board location, it returns im- mediately. Note that, if COUNT starts on a stone and operates as described above, the recursive calls to COUNT will carry the center of attention all over the group and onto all neighbor- ing points. The invariant assertion is satisfied because COUNT progresses one step each time only from stones in the group, as sketched in figure 4. The algorithm for COUNT is specified concisely in listing 1 using a kind of "structured English." The rest of the Go-playing program will be specified similarly, as a collection of modules like COUNT. Recursion is not difficult to imple- ment; COUNT just calls itself with the usual jump-to-subroutine instruc- tion for each of the neighboring points. The current board location is in a register; it is saved on the KIM stack before it is replaced by the loca- tion of each neighboring point, and then restored upon return from each call. The size of the connected group tut TAJTYPTJ CI OP¥ "PT T TQ™ PUT TIME AND REMOTE inun u i^rvA^i^wv^rv j. i^ ^ o control in your apple ii The THUNDERCLOCK PLUS is two peripheral systems on one card for your APPLE II OR II PLUS. 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BYTE April 1981 107 is limited by the size of the stack; one byte of board location plus two bytes of return address are pushed for each call, and the calls are nested as the algorithm "walks" around the group. A 100-byte stack can handle a 33-stone group. A group of that size would occur, if at all, only near the end of the game, when Wally's play deteriorates for other reasons anyway. Main Loop After COUNT was coded, a reasonable overall structure for a pro- gram to use it followed quickly. The main loop is specified in listing 2. The "consequences" of counting a group of stones include removing it from the board (zero out the board locations) if it has no liberties; other conse- quences have to do with suggesting tentative moves for Wally. Wally always plays black, in accordance with the Go tradition of giving the black stones to the weaker player. The pattern-matching facility was not implemented immediately. In fact, the first version of the program chose black moves randomly, trying again if it hit upon an occupied point. At least the capturing of black groups could be tested, and, for the most part, it was playing legal Go. Tactics and Priorities The next step in the design of the program was the decision that Wally would make contact moves, adjacent to white stones. In this way, the pro- gram would appear to be attempting to capture white groups, and would eventually fill up the liberties of each white group and capture it, if no defensive action were taken. At the same time, it was clear that Wally also should take some defen- sive moves to avoid capture. This brought up the question of priorities: when is a black group threatened enough so that Wally should stop attacking white and make a defensive move instead? The answer had to be based on the number of liberties re- maining in the black and white groups. It was decided that threats would be ignored until a black group had been reduced down to one or two liberties. Otherwise, Wally attacks whichever white group has the least number of liberties, because that group promises the best chance of be- ing captured. This strategy was implemented by associating a number of liberties with each suggested black move — namely, the number of liberties remaining for the group contacted by the stone. When a move is suggested, such as some liberty of a white group being Figure 4: How the procedure COUNT works. When tracing a black group, COUNT begins on a stone in the group and calls itself recursively to look at the four neighboring locations. If a neighbor is a black stone, the process is repeated until all stones in the connected group have been found. All unoccupied points adjacent to stones in the groups (ie: liber- ties) are also found and counted. ft ROOtS IRISH FRMILV H€MTflG€ ft Search for your Irish Family Roots through a unique Micro-Program from Ireland. Eiron Computers are proud to offer you an original computerized Irish Family Heritage Program, containing a summary of every Irish Family and areas from which they originated. Also a background summary and emigration dates. Included are Map with Crest names and Family locations Price: $100. Send To: Eiron Computers Ltd., Allow 28 days for delivery Eiron House, Park Road, Mastercharge, American Express Dun Laoghaire, Diners club Visa ' Co. Dublin. IRELAND Tel:808575/805045 Cables: Eiron, Dublin. Telex: 31502 or Personal Cheque accepted. Add $5 for Post & Packaging. **When ordering state your Name, Address and Disk Type and Format e.g. North Star Horizon 5V*" Single Density, and whether you are using North Star, TRS-80, Apple or PET, etc. EIRON COMPUTERS are distributors of North Star, NEC and Epson Products. 108 April 1981 © BYTE Publications Inc Circle 74 on Inquiry card. WHYCIS COBOL LETS YOUR MICROCOMPUTER PERFORM LIKEA MAINF Now, you can use a microcomputer for sophisticated business applications . . .because now there's CIS COBOL. Micro Focus developed this COBOL so your microcomputer can run the same programs as a minicomputer or a mainframe. CIS COBOL is Micro Focus' Compact, Interactive, Standard COBOL which offers the advantages of COBOL . . . powerful data structure features, English- like language, existing programmer expertise ... to provide you with a full commercial language. 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Forms The FORMS utility lets you build a screen layout online at the CRT. Then it automatically generates COBOL record descriptions for inclusion in your program. Forms -2 A superset of FORMS, it eliminates the need to write simple data entry and inquiry programs, because the programs can be automatically generated from screen definitions. Environment CIS COBOL products run on the 8080 or Z80 microprocessors under the CP/M* operating system, and on the LSI-11 or PDP-11 processors under RT-11. They are distributed in a variety of disk formats and come with a utility that enables you to use any make of CRT. OEMs Intel has adopted CIS COBOL and offers it (as iCIS-COBOL) for their Intellec and Intellec II systems. Ideal for OEM's or private label, CIS COBOL was developed entirely by Micro Focus. Send inquiries for CIS COBOL object packs and application vendor terms to MICRO FOCUS or its licensed distributors. Distributor terms also available from MICRO FOCUS. MM MM MM MM mm MM MM M MM MM MM mm MM mm 1 Send me more information for: B4 □ Single Copy Users □ Reseller and Distributor Licensing Name Title Company Address City/State Zip/Phone Computer ModeL Version of DOS_ mm MICRO FOCUS™ Micro Focus Inc. • 1601 Civic Center Drive Santa Clara • CA 95050 • Tel: (408) 984-6961 ■ Telex: 171-135 MISSION SNTA U.K. Office • 58 Acacia Road • St. Johns Wood < London NWS 6AG • Tel: 01 722 8843 • Telex: 228536 MICROF G L.——— ________ J CIS COBOL distributors include: Vector Graphic, Onyx Systems, Altns Computer Systems, Lifeboat Associates, Research Machines. Telecomputing, Modular Business Systems, Rail, Midlectron, Rostronics and Johnson-Laird Inc. i Intellec is a trademark of Intel Corp. *CP/M is a trademark of Digital Research Inc. BYTE April 1981 109 Listing 1: Structured English specification of COUNT module to find and count the liberties of a connected group containing a stone at point "x" of color "color." COUNT calls itself recursively, saving x on the push-down stack during each call. COUNT(x, color): IF x is not off the edge THEN IF there is a stone at x AND it is the given color AND it is not marked THEN mark it CALL COUNT(NORTH(x), color) CALL COUNT(EAST(x), color) CALL COUNT(SOUTH(x), color) CALL COUNT(WEST(x), color) ELSE IF there is no stone at x THEN mark the point as a liberty increment the liberty count END END counted, a best (move, liberties) pair is updated if the new move is adjacent to a group of a smaller or equal number of liberties. Since black groups are counted after the phase in which white groups are counted, a move by black in contact with a black group with one or two liberties is automatically preferred to a move adjacent to a white group with the same number of liberties. An excep- tion was put in later: when Wally finds a chance to capture a white group on the next move, he always takes it, even if some black group also has only one liberty. There is some doubt whether this exception was wise, however. Ko and Illegal Moves There are two situations in which a move on an unoccupied point is illegal. A move that leaves one's own group with no liberties is illegal. Figure 5a shows a move by black that would be illegal because the resulting black group would have no liberties. A move resulting in the capture of an opponent's group, as in figure 5b, is permissible because removing the captured group creates at least one liberty. The second type of illegal move arises from a ko, illustrated in figure 6a. If white captures the central black stone on his next move, the position will look as in figure 6b. Now black can capture the white stone and reproduce the original position in figure 6a. This could go on forever. To prevent such infinite repetition, the Rule of Ko was introduced: no Listing 2: Module specification for the main loop of the Go- playing program and two of its called modules. MAIN: place black handicap stones LOOP display the board get white's move from keyboard CALL WEFFECT for the effect of white's move CALL BEFFECT to obtain a tentative black move CALL PATS to check for a pattern match place black stone END WEFFECT: FOR each point x with a black stone DO CALL COUNT(x,black) IF the group has no liberties THEN remove its stones ELSE IF the group has at least one liberty THEN choose a liberty not on edge line IF the group has 1 or 2 liberties THEN CALL EVAL for the chosen liberty END END BEFFECT: FOR each point x with a white stone DO CALL COUNT(x,white) IF the group has exactly 1 liberty THEN designate it as the black move remove the white stones EXIT ELSE IF the group has 2 or more liberties THEN choose a liberty CALL EVAL for the chosen liberty END END rn Plug hi i 1.-100™ new CPU Boardset for S-10O computers. Go with the power of the Pascal Micro- engine! 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The point marked x in 5a is illegal for black because it would result in a black group with no liberties. The point marked x in 5b is permissible, however, because it captures the two white stones, leaving the inner black group with two liberties. player may move so as to reproduce the board position existing just prior to his opponent's last move. A move must be made elsewhere to change the board position before the ko capture is allowed. Lookahead Kos are common and often critical in master games, but at Wally's level it was simpler to leave out the Rule of Ko. However, it is essential to avoid suicidal or totally wasted moves which fill in the last liberty of a group, or leave it only one liberty, so that the group will be captured anyway. Hence a limited lookahead capability was adopted. The last step in evaluating a suggested black move is to put the stone down tentatively and count the liberties of the resulting black group. This is done by calling COUNT. The move is rejected if the resulting group does not have at least two liberties. The complete move evaluation module, EVAL, is shown in listing 3. The module LOOKAHEAD saves the current (move, liberties) pair before COUNT is called with the tentative black stone in place. Pattern Matching Wally's most intelligent-looking moves are pattern matches. There are common configurations of stones which suggest an obvious next move to a good player. Wally has a table of Figure 6: Ko. In 6a, white can capture the black stone, resulting in 6b. It is illegal for black to restore 6a immediately by recap- turing the white stone; he must wait a turn. patterns of this sort; these patterns are illustrated in figure 7. Each pat- tern includes one white stone and two black stones, with a third black move indicated. Patterns 7a thru 7e repre- sent responses to threatened connec- tions. Patterns 7f and 7g create good "shape." In Go, as in other spheres, there is truth to the motto, "In unity there is strength." The first step in capturing a group of stones is to cut it off from any other large groups nearby. Two weak groups, when connected into a single large group, often have a much better chance of survival. That is why defensive moves like figures 7a thru 7e are important. Good shape in Go is a local posi- tional strength. It is characterized by diamond-shaped configurations, or box-like shapes with at least two solid walls. These patterns enclose an area in an easily defended way, and serve as a basis for expansion. Moves like those in figures 7f and 7g are ag- gressive moves that take area while expanding against the opponent's outposts. The program looks at each white stone, trying to find two black stones near it in the same relative positions as in one of the patterns. 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The large-capacity A-70 disk drive with controller is only $699, with the second drive priced at only $599. Call or write us today to order your new Micro-Sci disk system. jut-so 17742 Irvine Boulevard, Suite 205, Tustin, California 92680 / Phone: 714/731-9461 / Telex: 910-346-6739 MH^Mftya are found and the point for the black move is unoccupied, the black move is returned for evaluation. Each pattern must be considered in all possible orientations around the Listing 3: Module specifications for move evaluation, lookahead, and pattern matching. E VAL(move , liberties) : GLOBAL (best-move, best-liberties) IF liberties < best-liberties AND LOOKAHEAD(move) a 2 THEN best-move = move best-liberties = liberties END LOOKAHEAD(move): place black stone at move CALL COUNT(move,black) remove black stone RETURN count of liberties PATS: FOR each white stone DO IF there is a pattern in the table centered on that white stone THEN get suggested black move y CALL EVAL(y,2) EXIT END END white stone. Three-stone patterns have either four or eight orientations, depending on their lateral symmetry. The program trades table space against program space by performing 180° rotations automatically. Thus, two or four table entries representing different orientations of each pattern are needed to account for all possibilities. Pattern matches are checked last, because they almost always take priority over moves arising from the earlier phase of counting the liberties of groups. Pattern-match moves are associated with an artificial figure of two liberties to set their priority. Thus, if Wally can capture a white group, or avoid the capture of a black group having one liberty, he will do so despite any pattern matches. The priorities of the patterns are deter- mined by the order in which they are checked, since the first match found is returned. Ghost Stones The edge of the Go board is strategically important because it helps to wall off areas. An attempt by white, for example, to invade be- (212) 986-7690 MAIL ORDER ONLY Micro Computer Your On* Stop For. . .Quality and Huge Savings i»iit_ru \_orri[Juier ■" ■ •"* ■ discount; QUALITY • DELIVERY • SERVICE 60 E. 42nd St. Suite 411 New York, NY 10017 ., CENTRONICS CALL FOR PRICES ATARI 800— $795 APF IMl - $495 IM2 - $988 COMMODORE 16K - $888 32K - $1088 2022 - $695 2040 - $1088 8050 - $1535 8032 - $1495 XYMEC HQ 1000 - $2395 NEC SPINWRITER 5510 - $2795 5520 - $2990 SALE! EPSON MX-80 EPSON MX- 70 PAPER TIGER 445 & 460 CALL FOR PRICE SUPERBRAIN* 32K - $2445 64K - $2749 64KQD - $3395 flnVnMHnKEaW DIABLO 630 $2195 1730 - $2195 MAIL ORDER ONLY Send Certified Check (Personal or Company Checks require 2 weeks to clear.) We pay all shipping and insurance charges except items marked with asterisk. VISA, MasterCharge add 5% N.Y.S. Residents add appropriate sales tax. * (DENOTES ITEMS SHIPPED F.O.B. NYC) PHONE (212) 986-7690 tween a black stone and the edge of the board should be defended against. The first five patterns in figure 7 already defend against threatened connections; why not use them to pro- tect the connection between a stone and the edge of the board? Imagine that there is an additional row of black "ghost" stones all around the board. As figure 8 shows, a white move near the edge can then invoke a pattern. This idea was implemented in the pattern match by allowing off- board positions to count as black stones tested for in each pattern. Edge Moves One of the most startling im- provements in Wally's performance resulted from a simple observation in the first few games. Groups on the edge of the board, when attacked, often extended fruitlessly along the edge, as in figure 9. A prohibition against edge moves, except to capture or on a pattern match, was added. Wally's play began at that moment to take on the character of an opponent to be reckoned with. Handicaps Go has a handicap system that allows an expert to play an even and interesting game with a novice. Black is given a head start of two to nine stones on designated points — the ones marked with black spots on the board (see figure 1). The handicap stones are placed symmetrically like die spots, except that a handicap of three stones is placed on three corners. Ad- ditional handicap points, for a total of up to seventeen stones, were added for Wally's benefit, since it was not expected that he would be a strong player. Each additional handicap stone accounts for roughly 10 points difference in score. The handicap stones help to make up for Wally's lack of overall strategy. The handicap points are good points to occupy early in the game, so a large handicap solves much of the strategy problem. Eyes and Life Wally has a blind spot that costs him dearly against experienced players: he does not understand that any group, no matter how large, will be captured unless it has two "eyes," or sufficient space to make them. An eye is an unoccupied point or con- nected group of points. A group enclosing two eyes is immune from 114 April 1981 © BYTE Publications lnc HOWS YOUR MEMORY? Our MEMORIES Have Made US Famous! WHY? Reliability! That's the secret of our success. We are dedicated to producing the most reliable memories possible for the S-100 bus and the new IEEE S-100 bus. Flexibility! No matter what CPU you use, we have the memory for you. SUPERAM™ 2 -We've delivered over 5,000 of these 64K dynamic RAM boards to OEMs worldwide. This board sets the standard for reliable operation. SUPERAM™ 4- Now available for Z80A and 8085 A users, with bank select and optional parity bit. SUPERAM™ 5 -Our forthcom- ing IEEE-696 (S-100) compatible RAM will provide 64 Kbytes of dynamic RAM as either 32Kxl6 or 64Kx8. With ECC, too! Announcing the SUPERMEM™ ECC! This is the ultimate in memory Circle 79 on inquiry card. Shown Left to Right: SUPERAM 4 SUPERMEM-ECC SUPERAM 2 data protection: built-in automatic er- ror correction. The SUPERMEM transparently corrects single bit errors and detects double bit errors. We'll Design One for You! If you have a special situation that calls for a custom design in- volving memory, processors, con- trollers, or even complete systems, give PI1CEON a call. We might have the answer to your product need. And That's Not All! We also supply the following Microcomputer Boards: • C-86 - 16-bit 8086 processor board with multi-processor arbitra- tion logic, on-board PROM and RS-232 port. • V-100 - 80x24 high-speed video output board. • D-100 — Coming soon, the answer to 5V4 and 8-inch Win- chester control. WRITE FOR OUR NEW BROCHURE TM JM^Mq OEM Computer Products 2350 Bering Drive San Jose, CA 95131 (408) 946-8030 ©puceon. inc. i9so BYTE April 1981 115 We've lowered the No, the low CompuServe $5.00 per hour charge hasn't changed, but the world of information we offer is growing steadily. Of CompuServe's 22 large computer systems, 10 are housed here in our Dublin, Ohio Computer Center. More Computer Power The number of CompuServe customers keeps growing — now more than 8,000 strong. The more customers we have, the more computer power and access lines we dedicate to our Information Service. Our 22 mainframe computer systems provide sufficient power and capacity to serve thousands more. More News In addition to the Associated Press, we've added more news. Read The New York Times and all the news that's fit to print, including Broadway show and movie reviews, stories from Pulitzer Prize-winning writers and more. We are continually adding new features to the information service, so check our "What's New" section regularly to see what other information is available. TRS-80® Color Computer and Videotex® The CompuServe Information Service is sold in Radio Shack® Stores and, in addition to all the major brands of com- puters and terminals, can be used with the new TRS-80 Color Computer and Videotex terminal. Our special software formats the information in easy-to-read pages. Go forward, backward, anywhere in the CompuServe Information Service databases — even directly to a page of information. Big System Reliability When we say we're reliable, we mean it. In fact CompuServe computers were up and running for a 99.6 percent reliability factor last year. We've also built in many "invisible" features like data error detection and retransmission — all those technical enhancements which add up to the CompuServe Information Service being ready to use when you're ready to use it. Radio Shack, TRS-80 and Videotex are trademarks of Tandy Corporation. ATARI is a trademark of ATARI, Inc. 116 BYTE April 1981 cost of the world. Access to all the CompuServe services, including electronic mail; bulletin board; CB simulation; newsletters from Radio Shack 1 ", Atari", and others; up to128K storage free plus all the services listed here are yours. Access time is only 8V3 cents per minute between 6 PM and 5AM weekdays and all day weekends, billed to your charge card. It's a local phone hook-up in more than 260 U.S. cities. There's an energy management system, home repair tips, discount information, personal health infor- mation and more. Better Homes & Gardens provides household information such as recipes, nutritional analyses and meal plans. All kinds of games (including some for the kids), book and movie reviews, astrology and the latest sporting event news — even point spreads and injury lists. There's the CompuServe line printer art gallery and even a national user opinion poll for instant feedback on current events. A complete program. The AP financial wire, newspaper financial pages, Raylux Financial Advisory Service, the Commodity News Service and personal financial programs. At a slight additional charge, you can retrieve fundamental financial data on more than 1,700 companies from Value Line, and MicroQuote offers current and historical data and special market reports on more than 40,000 stocks, bonds and options, updated daily. While the CompuServe Information Service is designed for everyone, MicroNET Personal Computing is for the knowledgeable computer hobbyist or business ^^^^^^^^^^^^^^^^" person. You can buy software and have it downloaded directly to your person computer. Use programming languages such asAPL-SF, EXTENDED BASIC, MACRO-10, SNOBOL, EXTENDED FORTRAN and PASCAL, use word processing and text editing programs. Not 1985, NOW! See for yourself what a state-of-the-art electronic information service can do. Get a demonstration at a Radio Shack" computer center or store — or write to us for further information. CompuServe Information Service Division 5000 Arlington Centre Blvd. Columbus, Ohio 43220 (614) 457-8600 Circle 80 on inquiry card. BYTE April 1981 117 4& 4&$t^ (a) (b) (c) : _- -^_- Turn your Apple into the world's most versatile personal computer. The SoftCard™ Solution. SoftCard turns your Apple into two computers. A Z-80 and a 6502. By adding a Z-80 microprocessor and CP/M to your Apple, SoftCard turns your Apple into a CP/M based machine. That means you can access the single largest body of microcomputer software in exist- ence. Two computers in one. And, the advantages of both. Plug and go. The SoftCard system starts with a Z-80 based circuit card. Just plug it into any slot (except 0) of your Apple. No modifications required. SoftCard supports most of your Apple peripherals, and, in 6502-mode, your Apple is still your Apple. CP/M for your Apple. You get CP/M on disk with the SoftCard package. It's a powerful and simple-to-use operating system. It supports more software than any other microcomputer operat- ing system. And that's the key to the versatility of the SoftCard/Apple. Circle 86 on inquiry card. BASIC included. A powerful tool, BASIC-80 is included in the SoftCard package. Running under CP/M, ANSI Standard BASIC-80 is the most powerful microcomputer BASIC available. It includes extensive disk I/O statements, error trapping, integer variables, 16-digit precision, exten- sive EDIT commands and string func- tions, high and low-res Apple graphics, PRINT USING, CHAIN and COM- MON, plus many additional com- mands. And, it's a BASIC you can compile with Microsoft's BASIC Compiler. More languages. With SoftCard and CP/M, you can add Microsoft's ANSI Standard COBOL, and FORTRAN, or Basic Compiler and Assembly Lan- guage Development System. All, more powerful tools for your Apple. Seeing is believing. See the SoftCard in operation at your Microsoft or Apple dealer. We think you'll agree that the SoftCard turns your Apple into the world's most versatile personal computer. Complete information? It's at your dealer's now. Or, we'll send it to you and include a dealer list. Write us. Call us. Or, circle the reader service card number below. SoftCard is a trademark of Microsoft. Apple II and Apple II Plus are registered trademarks of Apple Computer. Z-80 is a registered trademark of Zilog. Inc. CP/M is a registered trademark of Digital Research, Inc. /HCflQSOfT V CONSUMER^ PRODUCTS^ Microsoft Consumer Products, 400 108th Ave. N.E., Bellevue, WA 98004. (206) 454-1315 Text continued from page 122: The device first reads position / of the tape through the tape head, then places the value it finds into its register, R. If R contains a zero, the device executes the left side of pro- gram statement number Turing Pro- gram Counter (TPC). If R contains a 1, the device executes the right side of program statement number Turing Program Counter. Each side of each program state- ment contains a value for the variables W, D, and ADR. The sym- bol W indicates what is to be written on the tape. The symbol D indicates the direction to move the tape head: if D = 0, the tape head is moved one space to the left; if D = l, the tape head is moved one space to the right. The symbol ADR is the address of the next program statement to be ex- ecuted. Briefly, the device reads the tape, writes on the tape, moves the tape head, and transfers control to another program statement. The pro- gram presented in figure lb is a parity checker — that is, the machine reads two binary digits and writes a third to give the total 3 bits an odd number of Is — that is, odd parity. [It should be noted that the previously mentioned notation for a Turning Machine is not the one usual- ly encountered in classrooms and textbooks. A more formal definition defines a Turning Machine with the program expressed as a set of 5-tuples of the .following form: (current state, character being read, character to write over cur- rent character, next state, direction to move tape) where the particular 5-tuple to be ap- plied is the one that is given by the current state and the character being read. It can be seen that each line of the notation used in this article can be rewritten as two 5-tuples of the above form; therefore, the two notations are equivalent .... GW] The operation of a Turing Machine may be represented by a flowchart, as in figure 2. Suppose that the variables W, D, and ADR are contained in D(R,TPC) = 1 ? I- I I f START J 1 . READ TAPE INTO REGISTER R R = TAPE (1 ) WRITE CHARACTER TO TAPE TAPE(I ) = W(R,TPC) _/'direc ""N. = Rl TION\YE s GHT v? NO MOVE TAPE HEAD LEFT 1 = 1-1 MOVE TAPE HEAD RIGHT 1= 1 + 1 ' \ GET ADDRESS OF NEXT INSTRUCTION TPC = ADR { R ,TPC) Figure 2: Flowchart for the Turing Machine algorithm. In this algorithm, written primarily for a hardwired or assembly-language implementation, the only allowable characters that can be written are and 1. The only allowable movements for the tape head are left and right. The algorithm does not end as such, but a final or halting state can be implemented by the addition of two program lines that unconditionally loop to each other, denoting the end of the algorithm. This is done in the example of figure la. three arrays, each two-dimensional: W(R,TPC), D(R,TPC) and ADR (R,TPC). The first subscript corre- sponds to the value contained in reg- ister R, while the second subscript re- fers to the program statement num- ber. (In the example of figure 1, W(l,3) = 0, D(l,3) = l, and ADR(1,3)=3.) The variable I refers to the position of the tape. Hence, the tape is represented by a one-dimen- sional array, TAPE(Z). The variable TPC represents the Turing program counter — that is, the line of the Tur- ing program being referenced. These variables, along with the description, of the operation of a Turing Machine, are utilized in the flowchart of figure 2. So far, no restrictions have been placed on the values of TPC or the tape index /. Turing assumed that the program and tape were indefinitely large. In a practical Turing machine, the variable TPC takes on values up to and including the maximum number of program statements. The tape index / may take on values up to and including the number of spaces on the tape. It is usual to assume that when the value of / exceeds the length of the tape, it returns to the first posi- tion on the tape, so that the tape then becomes finite and connected to form a loop. We call such a restricted machine a practical Turing Machine (PTM). With these restrictions it is possible to construct a PTM from discrete digital components. A Hardware Version A hardwired version of a PTM utilizing integrated circuits can be readily constructed as described in the Millen article (see reference 3). In the present implementation, the program is stored in a 128 by 8-bit programmable memory circuit. (See figure 3.) The variables are the same as those used in the flow- chart. The temporary register holds the value of ADR(R,TPC). Register TPC points to a program statement. Register R selects the left or right side of the program statement. The value of I is held in a 12-bit binary up-down counter. The tape is represented by 4096 bits of programmable memory. The boxes labeled "address selector" operate like double-throw switches and facilitate loading and execution of programs. A maximum of sixty- four program statements may be Text continued on page 136 128 April 1981 © BYTE Publications Ire Circle 87 on inquiry card. - r • *' - - <** . a . - . .. •• t ""• mil ■ 01 ■ SBfc" Unretouched CAT 400 display. 242x256k 16 bits per pixel 128K byte imaae buffer Partial picture shown here to highlight detail quality Imao Analysis Systems, Inc . 999 McMillan St . N W . Atlanta. Ca ig courtesy of Earth Resouri And You Thought You Couldn't Afford Color Like This? Check our pricing. A system price for every- one's budget. We manufacture a full line of color graphic imaging systems, subsystems, and boards to fit your needs. Our CAT-100 FAMILY including the new CBX Series boasts high performance at reasonable costs. Features available: Real time video frame grabber input in monochrome or color. Reso- lutions to 640 pixels per line. 65.536 Simulta- neous colors out of a palette of 16 million colors. Standard RS-170 NTSC and RGB video output, and Image memory from 32K to 256K bytes. In addition we carry accessories and a steadily growing line of software sup- port packages. For more information call or write DIGITAL GRAPHIC SYSTEMS, INC.. 407 California Av- enue, Palo Alto, Calif. 94306. Telephone 415/ 321-8871. I ^DIGITAL ^GRAPHIC ^SY5TEMS,INC. DIS IC25 555 TRG THR OUT RST 3 1 4 . 2 IC22 7400 ^E^^ OCK IN O.OOljiF m 14 12 6 1 2 8 K CK CK PR C IC23 7476 15 9 16 4 11 + 5V ■IK RESET C CK CK J IC24 7476 14 12 11 10 _0_ SINGLE CLOCK 1 RESET CLOCK 2 CLOCK 2 CLOCK 3 CLOCK 4 STEP Figure 3: Schematic diagram for the hardwired Practical Turing Machine. The device is designed to be built on three small circuit cards, figures 3a thru 3c. In figure 3a, the clock board, IC23 and IC24 produce a four-phase clock used by the other boards. LEO ELECTRONICS 8921 S. 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Add $4.00 Please specify method S PRODUCT TTL LS244 1.20 LS245 1.20 LS283 95 LS367 .65 LS368 .65 LS373 1.40 LS374 1 .40 LS377 1 .45 S188 S189 S287 S288 S471 3.50 3.50 3.50 3.00 7.50 7489 1.65 V OLT REGS 340T5 .85 340T12 .85 320T5 .95 320T12 .95 TERMS: WE ACCEPT CASH, CHECK, OR MONEY ORDERS. CALIFORNIA RESIDENTS ADD 6% SALES TAX 130 April 1981 © BYTE Publications Inc Circle 88 on inquiry card. Circle 89 on Inquiry card. A s 175 Program That Makes your Microcomputer Worth Its Weight In Gold. •tfiE The Denver Software Company has developed, with the assistance of a Big Eight accounting firm, a financial package for microcomputers which accommodates the needs of both the very small- businessman and the household budget manager, and costs far less than you would imagine. The FINANCIAL PARTNER™ contains all essential accounting functions, and yet is easy to use. It also has built-in flexibility: Programming expertise and valuable time are not needed to get the FINANCIAL PARTNER™ ready to use. And most important, this is a complete package, containing the programs, language, operating system, and supplies. The beauty of the FINANCIAL PARTNER™ is that you don't have to be a professional bookkeeper or accountant to use it. Controller Jim Vogt says, "It is one of the simplest accounting systems I have ever worked with, and it has a great ability to produce timely and accurate financial statements for small business or home use." All the necessary "how-to" is detailed in a well-written, step-by-step reference manual. The FINANCIAL PARTNER™, which operates from menu selections, collects and organizes information for all of the standard categories: Assets, liabilities (including accounts payable), normal living expenses, deductible expenses (including all six deductions for personal Federal Income Tax returns), earned income (for both the wage earner and the self-employed), and other income and expenses. The provided chart of accounts is tailored for most users, but it can easily be modified by adding new accounts or changing descriptions. The FINANCIAL PARTNER™ generates standard financial reports — including a detail trial balance, income statement, and balance sheet — as well as batch proof listings, check register, vendor payable reports, and chart of accounts reports. The FINANCIAL PARTNER™ is available for Apple, Atari, Commodore, Ohio Scientific, Texas Instruments, Radio Shack, Zenith, and most other microcomputers. Minimum hardware requirements are: 48 K RAM, 140 K on-line storage, 40 x 24 or 80 x 24 display device, and almost any 80-column printer (optional). The FINANCIAL PARTNER™ is available from your local dealer or you can direct inquiries to: THE DENVER SOFTWARE COMPANY MANUFACTURERS OF MICROCOMPUTER SOFTWARE 36 Steele Street, Suite 19 • Denver, Colorado 80206 Dealer inquiries welcome. 303 321-4551. a. co imii *- s * a: o- Figure 3b: 77ie processor card. 1C1 is the Turing program memory; the lines coming into AO thru A6 of IC1 are the Turing Program Counter (TPC). IC7 stores the R (direction) bit, and IC9, IC10, and ICll store the Turing program address at which the program will start execution. The left/right switch designates which half of the Turing program word is written (switch open = left half) when the RUN /PROGRAM bit is set to PROGRAM. 132 April 1981 © BYTE Publications Inc HAVE WE GO! A PROGRAM FOR YOU IN 111 Attend the biggest public computer shows in the country. Each show has 100,000 square feet of display space fea- turing over 50 Million Dollars worth of software and hard- ware for business, industry, government, education, home and personal use. You'll see computers costing $150 to $250,000 including mini and micro computers, software, graphics, data and word processing equipment, telecommunications, office machines, electronic typewriters, peripheral equipment, supplies and com- puter services. All the major names are there including; IBM, Wang, DEC, Xerox, Burroughs, Data General, Qantel, Nixdorf, NEC, Radio Shack, Heathkit, Apple, RCA, Vector Graphic, and Commo- dore Pet. Plus, computerized video games, robots, com- \puter art, electronic gadgetry, and computer music to entertain, enthrall and educate kids, spouses and peo- ple who don't know a program from a memory disk. Don't miss the Coming Of The New Computers- J, Show Up For The Show that mixes business with pleasure. Admission is $5 for adults and $2 for chil- dren under 12 when accompanied by an adult. Ticket Information Send $5 per person with the name of the show you will attend to National Computer Shows, 824 Boylston Street, Chestnut Hill. Mass. 02167. Tel. 617 739 2000. Tickets can also be purchased at the show. DALLAS Dallas Market Hall 2200 STEMMONS FRWY AT INDUSTRIAL BLVD THURS-SUN APRIL 9-12 10 AM TO 7 PM CHICAGO McCormick Place SCHOESSLING HALL 23RD& THE LAKE THURS-SUN SEPTEMBER 10-13 10 AM TO 7 PM bUU i NEfRb § WASHINGTON, DC DC Armory/Starplex 2001 E. CAPITOL ST. SE (ECAPSTEXITOFFI295 -KENILWORTHFRWY) ACROSS FROM RFK STADIUM THURS-SUN SEPTEMBER 24-27 10 AM TO 7 PM BOSTON Hynes Auditorium PRUDENTIAL CENTER THURS-SUN OCTOBER 15-18 10 AM TO 7 PM — S-^S™— t" z £.3-5 - SHOH ATLANTA Atlanta Civic Center 395 PIEDMONT AVE NE AT RALPH McGILL BLVD THURS-SUN OCTOBER 29-NOVEMBER 1 10 AM TO 7 PM Circle 90 on inquiry card. BYTE April 1981 133 (3c) THREE UP/DOWN COUNTERS FOUR IK BY 1 BIT PROGRAMMABLE MEMORIES DIRECTION CLOCK 3 Figure 3c: The memory card. 1C12, IC13, and IC14 store the pointer I to the Practical Turing Machine tape, while IC15 thru IC18 store the tape itself. 6 t TAPE TAPE CLOCK 2 BIT BIT WRITE READ Bring the computer to your senses The Soundchaser' computer music system transforms the Apple II" into an expandable, professional quality, polyphonic keyboard synthesizer and sequencer, Sound- chaser's music modules include a 4 octave keyboard housed in an attractively finished wood cabinet com- plete with polyphonic interface card, connector and control software. The synthesizer voice card provides 3 analog/digital hybrid, studio quality programmable synthesizers. Each synthesizer consists of a wide range, waveform select oscillator, digitally controlled 24 dB/ octave, low pass resonant filter, user definable LFO. fully programmable envelope generators, and a digitally controlled amplifier. System software includes a 4 chan- nel sequencer which supports up to 12 synthesizers! Explore Soundchaser's musical horizons. Play the sounds at your fingertips. Keyboard: $650.00. 3 Synthesizer voice card: S350.00. Write or call for details. Dealer inquiries invited. (415) 747-0614 TV^WSSPORT ^-^DGSIGNS Soundchaser is a trademark of Passport Designs. Inc. Apple is a registered trademark of Apple Computer, Inc. Marketing: Box 21061, Minneapolis. MN 55421 Headauarters: Box 4/8, La Honda, CA 94020 134 April 1981 © BYTE Publications Inc Circle 91 on inquiry card. Circle 92 on inquiry card. MULTIUSER tmmtfn ON S- lOO BUS DESIGNED TO SATISFY A WIDE VARIETY OF APPLICATIONS. STANDARD INCLUDE: CP [VI 2.2 OPERATING SYSTEM, 64K EXPANDABLE, BANKSE- " MEMDRY,4MHZ Z80A CPU WITH 4 SERIAL AND 3 PARALLEL PORTS, RELIABLE B" FLOPPY DISK DRIVES IN A STURDY ALL METAL CABINET. mmmiiiigyi <:■ ..<-r--j; $ 49QO MP/M OPTIONAL. P.O.BOX 1847 SAN DIEGO, CA.! 7343-J RONSON RD.SAN DIEGO, CA. 17 14) 57 1-6371 Circle 93 on inquiry card. NNhatdo/ouwant your computer and video player to do thattheycan'tdonow? DA. □ B. DC. Display videotape segments then automatically switch to computer text. Display multiple-choice options at each stage of the presenta- tion, then, depending on the choice made, replay any portion of text and/or video, or move on to new material. Show any portion of the com- puter text and/or videotape (randomly accessed) depend- ing on the pace and/or choices of the user. □ D. ALL OF THE ABOVE do it all on one screen. and If you checked D, contact us for more information on Cavri Interactive Video. We offer a reasonably priced, sophisti- cated system that links an Apple* or an RS-232 interfacing computer with a Sony or Panasonic VCR and TV screen — with no modification. In- cluded are simple, straightforward in- structions for writing your programs. Plus frame-accurate stops and switches with no accumulated error. Write or call today and join the many companies, large and small, that are improving their audiovisual training and testing with the new technology pioneered by Cavri. Training, of course, is only one appli- cation. Now you can catalogue any- thing — for example, a museum can videotape its paintings, sculptures, and artifacts, then show them by artist, subject, date, or any other grouping, regardless of the sequence in which they were recorded on the videotape. Tell us your application, and we can help by supplying the system and guidance on programming and video- tape or videodisc production. Cayii interactive video 26 Trumbull Street, New Haven, CT0651 1 (203) 562-4979 "TM — Apple Computer Co. 136 April 1981 © BYTE Publications Inc (3d) PIN 18 ,.i— v, OF IC1 A5 I— > PIN 19 ..r—v, OF IC1 A4 I — -> PIN20 r— -^ OF IC1 A31_^> TIL209 TYPICAL 330J1 FOR 7 TYPICAL J» FOR 7 PIN 21 OF IC1 «o PIN22 ..r-^ OF IC1 A ll_> PIN 23 | OF IC1 *0l_> IC27 7404 o'f N ,C 8 7 E^>0i @^ + 5V MOST SIGNIFICANT BIT (MSB) TURING )PR0GRAM COUNTER LEAST SIGNIFICANT BIT(LSB) REGISTER R Figure 3d: This simple front panel for the PTM displays the address being pointed to by the Turing Program Counter and the value in the R register. Text continued from page 128: stored in 128 8-bit locations. Programs are stored by: Number Type + 5 V GND IC1 MCM6810 24 1 IC2 7475 5 12 IC3 7475 5 12 IC4 7475 5 12 IC5 74157 16 8 IC6 74157 16 8 IC7 7400 14 7 IC8 7400 14 7 IC9 7476 5 13 IC10 7476 5 13 IC11 7476 5 13 IC12 74191 16 8 IC13 74191 16 8 IC14 74191 16 8 IC15 2102 9 10 IC16 2102 9 10 IC17 2102 9 10 IC18 2102 9 10 IC19 7400 14 7 IC20 7400 14 7 IC21 7400 14 7 IC22 7400 14 7 IC23 7476 5 13 IC24 7476 5 13 IC25 555 8 1 IC26 7404 14 7 IC27 7404 14 7 Table 1: Power-wiring table for figures 3a, 3b, and 3c. • single-stepping the programming counter to the desired statement number, • selecting the proper side of the statement with the L/R switch, • loading the values for W, D, and ADR via the programming switches, and • depressing the "write" button. This sequence is repeated until all of the program has been entered. Execution is initiated by: • single-stepping the starting location of the Turing program into register TPC, and • switching to RUN mode. Timing signals are provided by a 4-phase clock through the inputs labeled clock 1 thru clock 4. This representation offers a relatively fast execution time of about 2 fis per cycle. Changes in the length of the tape or in the maximum number of program statements are extremely difficult to make. Output is limited only by the imagination and This Single Board.. i KMminB !>:• .» Mi : .is the Heart of the coprocessor World's it Multi-User System ... THE DISCOVERY MULTIP The dedicated power of this complete single board computer is provided to each user, making the DISCOVERY MULTIPROCESSOR unique among multi-user systems. With the power and expandability of distributed process- ing • With the economy of shared peripherals • With the flexibility of shared and public files • And all of this with full CP/M* and S-100 compatibility. Multiprocessing Software Our Distributed Processing Oper- ating System, dpc/os resides in the Service Processor, establishing a CP/M environment for each user and managing access to the shared system resources. Multiuser facilities are provided for print spooling, for interprocessor communication and for private, public and shared-update files. Several processors can be em- ployed concurrently by a single user via the enhanced batch submit facil- ities. And with DISCOVERY all CP/M compatible programs will execute without modification, thus protecting your software investment Multiprocessing Hardware The ACE 64 K Distributed Process- ing Single Board Computer, the dpc-180 gives the DISCOVERY MULTIPROCESSOR its own unique architecture. One DPC is dedicated to each user providing exclusive use of the onboard Z-80, 64Kram and serial I/O. Access to the shared resources is provided by an ex- panded DPC used as a Service Processor. Additional users can be added at any time by simply inserting additional DPC's.into the standard S-100 bus — up to a total of sixteen user processors in a single chassis ! *CP/M is a registered TM of Digital Research, Inc. DISCOVERY has been proven in installations throughout the World. If you need the Power of Multiprocessing... it's time you discovered us! 6 4« #0 The ACE DISCOVERY MULTIPROCESSOR dedi- cates a complete 64K Z-80 Distributed Processing single board Computer, the dpc-180'" to each user. An ex- panded DPC coordinates all of the system activities. Multiuser mainframes with 192K ram start at under $6000. The 64K dpc-180 "is priced at $1395. Immediate delivery. A complete line of standard peripherals including a 26M byte hard disk subsystem can be supplied on request Dealer and OEM inquiries are invited. Visit our Booth at the NCC Action Computer Enterprise, Inc. The Multiprocessing Company 55 West Del Mar Boulevard, Pasadena, California 91105 USA • Cable ACEPAS Pasadena • (213) 793-2440 means of the user. In my prototype, a row of light-emitting diodes (LEDs) displays the contents of register R and register TPC (see figure 5). Com- ponents for this hardwired represen- tation of a PTM cost about $80. An Assembly-Language Version Another implementation of a Prac- tical Turing Machine is with a micro- processor. The code given in listing 1 is designed to run with only 512 bytes of memory and a Motorola 6800 microprocessor. The main program, as written, uses monitor routines available on the Heathkit ET-3400 Trainer. The tape index / is represented by the contents of loca- tions 12 and II. The variable II points to an 8-bit word in the tape array. The 3 least significant bits of the con- tents of the location 12 point to a bit within that word. A maximum of thirty-two program statements may be stored in 64 bytes of memory. Subroutine RUN is divided into five parts: •statements 0000 thru 0016 (hexa- decimal) load R with the value of TAPE (/) STM# R = R = l 0080 00A0 1 0081 0OA1 2 0082 00A2 3 0083 00A3 • • • • • • • • • 31 009F 00BF WD — ADR — 7 6 5 4 3 2 10 Bit locations Figure 4: Memory map of assembly- language implementation of a Practical Turing Machine. Memory locations hexa- decimal 0080 thru 00BF are used to store a program of up to thirty-two steps, with 2 bytes being used to store each statement line. The character to be written, W, is in bit 7 of a given byte. The direction of tape head movement, D, is in bit 6. The state- ment number of the next statement to be executed is stored in bits 4 thru of the byte. Bit 5 is unused. •statements 0017 thru 001C (hexa- decimal) establish an offset for find- ing the proper half of a Turing pro- gram statement •statements 001D thru 002F (hexa- decimal) print W(R,TPC) on the TAPE • statements 0030 thru 0044 (hexa- decimal) increment or decrement / • statements 0045 thru 0049 (hexa- decimal) restore TPC to the next pro- gram statement number The main program provides output through the ET-3400 monitor routines and LED displays. Details of storage of the Turing program appear in figure 4. Each side of each program statement is stored in a separate memory location. The value of W occupies the most signifi- cant bit and the value of D occupies the next most significant bit. The value of ADR is stored in the 5 least significant bits of a Turing program statement location. Program statements are entered directly into memory locations using monitor routines available on the trainer. Execution is initiated by: entering the starting location of the irine nroeram into the location Turing TPC, program into the location Text continued on page 146 Why Do Professionals Prefer BECAUSE • Unique software • Technical support • Quick delivery • Established company • Release 2 CP/M* (some packages under UNIX* and TRSD8S S ) • Quality software • in-house expertise • Fast response • User orientation • Competitive prices • Customer service • \fejbaitm* )6 media • Onyx hardware (CP/M and UNIX versions). BECAUSE Unique swift routing cybernetics response system gives you no-nonsense technical answers that save you time. Call: (714) 848-1922. Business Medical Real Estate Computer Systems • NEW RM/COBOL 1 applications: * Order Entry/Inventory • Receivables • Payables • General Ledger • Financial Modeling • Client Account- ing— and more on the way! • NEW CBASIC2 1 applications: * REAP (Real Estate Acquisition Package). Software from Cybernetics? RM/COBOL— The new standard for microcomputer COBOL1I The only COBOL for CP/M (also on TRSDOS & UNIX) with alternate keys (multi-key ISAM), CRT screen handling, Interactive debug, and the most useful Level 2 features. Compat- ible with RSCOBOL*— but runs fatter. Plus existing CBASIC2 packages: APH (Automated Patient History) Osborne & Assoc— Payroll ♦ Payables/Receivables • General Ledger NAD' (Name and Address) PMS (Property Management System) Inquire for details Trademarks of: 'Ryan-McFarland Corp.. 'Compiler Systems. Inc.. 'Digital Research. 'Bell Telephone Laboratories. Inc., h Tandy Corp., "Verbatim, Inc.. 'Cybernetics, Inc., "Struc- tured Systems Group, Inc., 'Small Business Applications, Inc. TRS-80 1 , Model II CP/M— The fastest Mod II CP/M with the most features. Out- standing leaching documentation for newcomers to CP/M, multiple CRT emula- tion, down loading package, support for CORVUS 10 Mb hard disk. Marjy addi- tional user-oriented features. And system software packages: MAGIC WAND' Editing/Word Processing CBASIC2 Compiler BASIC QSORT- Soft Merge Package ■ js^i? le.Qye.isj&ieys.ij.iy&is. us- 15- 8041 Newman Ave., Suite 208 Huntington Beach, CA 92647 (714) 848-1922 138 April 1981 © BYTE Publications Inc Circle 95 on Inquiry card. ALL NEW GUIDES from OSBORNE/McGraw-Hill The Apple II User's Guide by Lon Poole, Martin McNiff, and Steven Cook #46-2, $15. □ This Guide is the key to unlocking the full power of your Apple II or Apple II plus computer. The Apple II User's Guide brings together in one place a wealth of information for Apple computer users. It will tell you more about your Apple than any other single source. This book will save you both time and effort. No longer will you have to search endlessly for useful information. It's all here, in the Apple II User's Guide, thoughtfully organized and easy to use. Topics include: "Applesoft and Integer BASIC pro- gramming - especially how lo make the best use of Apple's sound, color and graphics capabi- lities. The book presents a thorough description of every BASIC statement, command and function. 'Advanced programming - special sections describe High Resolution graphics techniques and other ad- vanced applications. "Hardware features - the disk drive and printer are covered in sepa- rate chapters. "Machine level programming - al- though not a machine language programming guide, this book covers the Machine Language Monitor in detail. "Apple is a trademark of the Apple Computer Corporation. PET/CBM Personal Computer Guide Second Edition by Adam Osborne and Carroll Donahue #55-1. $15. □ The PET/CBM Personal Computer Guide is a step-by-step guide that assumes no prior knowledge of computers. If you can read En- glish, you can use this book. This revised second edition provides even more useful material than the popular first edition. It covers the most recent CBM products: the CBM 8000 and 4000 series computers, the 2040 and 8050 disk drives, and programmable printers. Adam Osborne co-authored this new edition. He has re-writien it to be a step-by -step BASIC tutorial. So if you don't know BASIC, don't worry. This book will teach you both BASIC and CBM BASIC. If you're thinking about buying any personal computer, this book will show you what the PET can do for you. If you've just bought a PET or CBM. this is the book you must have to really understand your computer. By using the ex- amples found in this book you'll quickly get your PET/CBM up and running. These examples are thoroughly documented so you can learn how and why the programs work. It's the "how" and "why" that are important in learning to make the PET work efficiently for you. The PET Personal Computer Guide covers everything you'll need to be master of your PET. "PET and CBM are both trademarks of Commodore Business Machines. % > "D c (0 O c E (D m H ' O CO s "O CD (A o 3 SL O o 3 ■o c 5" O c a a> CP/M User's Guide by Thorn Hogan «44-6$i2 99D If you haven't yet purchased CP/M for your system, the CP/M User's Guide will make your first use of CP/M easy. If you already have CP/M, this book will help you modify your system and let you "jockey your disks "like an expert. The CP/M User's Guide describes types of CP/M and their compatibility. It includes a discussion of conventions used lo create file names and command lines. Numerous sample screen displays for each version of CP/M graphically explain each operator command and computer response. CP/M's Assembly Language Utilities are described for the non-technical reader who wants maximum use of CP/M's capabilities. The book also discusses how application packages, high level languages, solution programs, and other support programs combine with CP/M to answer a user's individual needs. You'll also find an explanation of MP/M and CP/NETas well as the technical aspects of CP/M's internal structure which will permit you to make simple modifications. A full glossary and several useful appendices are included. - CP/M is a trademark ot Digital Research Corporation. The Business System Buyer's Guide by Adam Osborne #47-0 $7.95 □ When you enter the marketplace of small business computers you face a bewilder- ing array of products, prices, features, and fables. This guide cuts through the jargon and unravels the task of buying the right computer system. Dr. Osborne is the foremost authority on the use of computers in small businesses. Here, he helps you to analyze your computer needs by applying the same know-how that made your business a success. This book provides solid information on how to determine your needs, how to choose software and hardware for all business applications, what to expect from vendors, what to avoid, and what questions you must ask. It also provides a wealth of detailed information on products, manufacturers, retailers, and the whole micro- computer marketplace. Purchasing a computer system for any business is a complex process, bul it need nol be a frustrating one. This book will help. Before you buy any computer, read this book. You'll never make a better investment. Make check payable to: {f\ OSBORNE/McGraw-HIII 630 Bancroft Way, Berkeley, CA 94710 Dept. B14 Phone Orders:(415) 548-2805 IS Address . City/State/Zip Plus n.75/item 4th class a$1.25/item UPS a$2.50/item Air Mail n$4.00/item Overseas (California residents add applicable lax ) □ Please send me your free catalog. Total amount enclosed $ Card U . or charge my QVisa DM aster charge Expiration Date Signature _ Listing 1: Listing for implementation of the Practical Turing Machine in 6800 machine code. The program uses routines from the Heathkit ET-3400 microprocessor trainer at hexadecimal locations 0058 and 005B. MICRO-TURING PRACTICAL TURING MACHINE SIMULATOR FOR USE WITH A 6800 MPU AND AT LEAST 512 BYTES OF RAM. THE MAIN PROGRAM USES MONITOR ROUTINES AVAILABLE ON HEATHKIT "S MODEL ET-3400 MICROPROCESSOR TRAINER. WRITTEN BY JIM WILLIS PHYSICS DEPT. UNC CHAPEL HILL. CHAPEL HILL , NC . 27514. MICRO-TURING COMMENTS " READ TAPE " SET UP TAPE MASK FROM (12) A=00000001 B = I2 B=00000111 .AND. B IF (B=0) GO TO NEXT A=2*A B=B-1 GO TO FIRST R=B(=0) " LOAD R WITH TAPE (12,11) X=I1 IF ( (A.AND.TAPE(Il) ) .EQ.O) Z=1,ELSE Z=0 IF (Z=l) GO TO ENDR B=B + 1 R=B(=1) " LOAD B WITH TURING PROGRAM STM(R,TPC) B=TPC B=B+$20 TPC=B X=TPC B=TURING PROGRAM STM(R,TPC) X=I1 " WRITE ON TAPE IF( (B. AND. 10000000) .EQ.O) Z=1,ELSE Z=0 IF (Z=l) GO TO WZERO A=A.OR.TAPE(Il) GO TO ENDW A=.NOT.A A=A.AND.TAPE(I1) TAPE(I1)=A " MOVE TAPE POINTER X=$004A IF( (B. AND. 01000000) .EQ.O) Z=1,ELSE Z=0 IF (Z=l) GO TO DEC1 " INCREMENT (12, II) 11=11+1 IF(I1.NE.-128) GO TO ENDR 12=12+1 GO TO ENDD " DECREMENT (12,11) 11=11-1 IF(I1.NE.127) GO TO ENDD 12=12-1 " TPC=ADR(R,TPC) B=B. AND. 00011111 TPC=B RETURN MEM. LOC. OP. CODE LABEL MNEMOMIC 0000 86 01 RUN LDA A # $01 0002 D6 4A LDA B 12 0004 C4 07 AND B # $07 0006 27 04 FIRST BEQ NEXT 0008 48 ASL A 0009 5A DEC B 00 0A 20 FA BRA FIRST oooc D7 4F NEXT STA B R 000E DE 4B LDX 11 0010 A 5 00 BIT A $00, X 0012 27 09 BEQ ENDR 0014 5C INC B 0015 D7 4F STA B R 0017 D6 4E LDA B TPC 0019 CB 20 ADD B # $20 001B D7 4E STA B TPC 001D DE 4D ENDR LDX TPC 001F E6 80 LDA B $80, X 0021 DE 4B LDX 11 0023 C5 80 BIT B # $80 0025 27 04 BEQ WZERO 0027 AA 00 ORA A $00, X 0029 20 03 BRA ENDW 002B 43 WZERO COM A 002C A4 00 AND A $00, X 002E A7 00 ENDW STA A $00, X 0030 CE 00 4A LDX # $004A 0033 C5 40 BIT B # $40 0035 27 08 BEQ DEC1 0037 6C 02 INC $02, X 0039 28 0A BVC ENDD 003B 6C 00 INC $00, X 003D 20 06 BRA ENDD 003F 6A 02 DEC1 DEC $02, X 0041 28 02 BVC ENDD 0043 6A 00 DEC $00, X 0045 C4 IF ENDD AND B # $1F 0047 E7 04 STA B $04, X 0049 39 RTS 004A XX 12 (12) 004B 01 $01 004C XX 11 (ID 004D 00 $00 " VARIABLES 12 II Listing 1 continued on page 142 140 April 1981 © BYTE Publications Ire Circle 101 on inquiry card. The largest selection of software from the world's largest software publisher. UCt N0.19V2 Write for our catalog with full program descriptions and specifications. DISK OPERATING SYSTEMS CP/M CONFIGURED FOR: APPLE II DIGITAL MICROSYSTEMS FDC3 DURANGO F-85 HEATH H8 AND H89 ICOM MICRO DISK ICOM 3712 ICOM 3812 ICOM 4511/PERTEC O3000 INTEL MDS MICROPOLIS FLOPPY DISK M ITS/ALTAI R MOSTEKMDX NORTH STAR 0SIC3 PRO-TECH HELIOS TRS-80 MODELI TRS-80 MODEL II TRS-80 MODEL III ZENITH Z89 MP/M FOR INTEL MDS HARD DISK INTEGRATION MODULES CORVUS WITH APPLE II SOFTCARD CORVUS WITH S100 AND TRS-80 MODEL II ICOM 4511/PERTEC D3000 KONAN PLUS CDC PHOENIX XCOMP SM/S PLUS CDC PHOENIX XCOMP DFC10 FOR PERTEC D3000 SYSTEMS TOOLS BUGANDuBUG TRS-80 MODEL II DESPOOL CP/M DISILOG CUSTOMIZATION DISTEL DISK EDIT UNLOCK EDIT-80 WORD-MASTER FILETRAN XASM-18 IBM/CPM XASM-48 MAC XASM-65 MACRO-80 XASM-68 PASM XMACRO-86 PLINK ZDT RAID Z80 DEVELOPMENT RECLAIM PACKAGE SID ZSID TELECOMMUNICATIONS LANGUAGES ALGOL-60 muSIMP APL/V80 NEVADA COBOL BASIC-80 PASCAL/M (COMPILER) PASCAL/MT BASIC-80 PASCAL/MT + (INTERPRETER) PASCAL/Z BDSCCOMPILEF PL/l-80 CBASIC-2 SMAL/80 CIS COBOL S-BASIC COBOL-80 TINYC FORTRAN-80 WSMITHSC KBASIC COMPILER muLISP XYBASIC LANGUAGE AND APPLICATIONS TOOLS BASIC UTILITY MDBS.RTL DISK M/SORT FOR DATASTAR COBOL-80 FABS PEARL FORMS 2 FOR QSORT CIS COBOL STRING BIT MAGSAMIII STRING/80 MAGSAM IV SUPER-SORT MDBS.DRS ULTRASORTII WORD PROCESSING SYSTEMS AND AIDS MAGIC WAND TEX LETTERIGHT TEXTWRITER III MICROSPELL WORD-STAR SPELLGUARD WORDINDEX DATA MANAGEMENT PACKAGES CONDOR HDBS MDBS MDBS.QRS WHATSIT? GENERAL PURPOSE APPLICATIONS CBS SELECTOR III-C2 SELECTOR IV MAIL LIST APPLICATIONS MAILING ADDRESS (PTREE) MAIL-MERGE FOR WORD-STAR NAD POSTMASTER BUSINESS APPLICATIONS ~ ACCOUNTS PAYABLE (PTREE) ACCOUNTS PAYABLE (SSG) ACCOUNTS RECEIVABLE (PTREE) ACCOUNTS RECEIVABLE (SSG) GENERAL LEDGER II (CPAIDS) GENERAL LEDGER (PTREE) GENERAL LEDGER (SSG) GLECTOR FOR SELECTOR III-C2 INVENTORY (PTREE) INVENTORY (SSG) PAYROLL (PTREE) PAYROLL (SSG) WordStar users unite .. . with Designed to assist users of WordStar maintain large documents, WORDINDEX is a list-making, tabulating and indexing champion. Generate a table of contents, a list of figures and a list of ta- bles, a sorted index, with index words on two levels: master and sub-references. In addition, you can re-number section numbers and page references, whenever the document has been changed. All automatically. WORDINDEX has the added attraction of user-selectable print control for all headings. WORDINDEX is also useful for indexing publications not in machine-readable form. WORDINDEX $195. Program With Full Documentation MICROSPELL SPELLING CORRECTION PROGRAM AVAILABLE FOR S295. LIFELINES PASCAL USER MANUAL AND REPORT PAYROLL WITH COST ACCOUNTING-CBASIC STRUCTURED MICROPROCESSOR PROGRAMMING USING CP/M-A SELF-TEACHING GUIDE NUMERICAL PROBLEM-SOLVING TOOLS ANALYST FPL muMATH STATPAK T/MAKER OTHER SPECIALIZED APPLICATIONS BSTAM BSTMS DATEBOOK ESQ-1 MASTER TAX PAS-3 DENTAL PAS-3 MEDICAL PROPERTY MANAGEMENT (PTREE) STANDARD TAX BOOKS AND PERIODICALS APL-AN INTERACTIVE APPROACH ACCOUNTS PAYABLE & ACCOUNTS RECEIVABLE-CBASIC 8080/Z80 ASSEMBLY LANGUAGE THE CP/M HANDBOOK THE C PROGRAMMING LANGUAGE FIFY BASIC EXERCISES GENERAL LEDGER-CBASIC ACCESSORIES DC 300 DATA CARTRIDGE HEAD CLEANING DISKETTE FLIPPY DISK KIT FLOPPY SAVER Program names and computer names are generally trademarks or service marks ol the author or manufacturing company. All software products have specific re- quirements for hardware and additional as- sociated software (e.g. operating system or language). All products are subject to terms-and condi- tions of sale. Copyright PHYSICS DEPARTMENT 120 " UNIVERSITY OF NORTH CAROLINA » CHAPEL. HILL NORTH CAROLINA, 130 " DESIGNED TO RUN ON UNCCC'S VERSION OF IBM'S 360/370 CALL -OS 140 " TURING ISO DIMENSION 17' APE < 128 ) 160 INTEGER *2 W(2r64) nB<2»64> >ABR<2i>64) i-TAPE<128) t TPC > WI yDI » ADR 1 1 T 170 DATA Y/'YV 180 1000 WRITE (3 » 100) 190 100 FORMAT ( ' HOW MANY SPACES IN THE TAPE? 128 MAX. ' ) 200 READ<1*#) MTAPE 2 1 I F ( H T A P E , G T , 1 28) MIA P E ~ 1 2 8 220 1001 WRITE (3v 102) 230 1 2 F R M A T < ' I N P U T T U R I N P R R A M , W » D » A D R 1 W 1 1 D 1 1 A D R 1 . W « 2 1" E N D ' ) 240 NSTM'-O 250 1 NDEX-NSTM-fl 260 WRITE (3»103)NSTM 270 103 FORMAT (' STM.NO. '*I2) 280 READ ( 1 t # ) W ( 1 » NDEX ) v D ( 1 , NDEX ) t ADR ( 1 . NDEX )»U(2» NDEX ) >HH2> NDEX ) r ADR < 2 » NDEX ) 290 I F ( N S T M , E 0.64)0 T 2 3 I! F ( W ( 1 r H D E X ) . G T ♦ 1 ) (3 T 2 310 NSTM^NSTM-fl 320 GOTO 1 330 2 WRITE<3»104) 340 104 FORM AT (' NO. WO DO ADRO Wl Dl ADR1 ') 350 DO 3 I~1»NSTM 360 N-I-l 370 WRITE<3»105)N»W<1»2 ) »D<1»I) »A0R(1»I) nW(2»I ) tBi2> I ) t ADR < 2 » I ) 380 105 FORMAT'-' ' »4I4 r ' \ ' v3I4) 390 3 CONTINUE 400 WRITE (3 1-106) 4 1 1 6 F R M A T ( ' I N P U T F I R S T T U R I N G P R G R AM STM . NO,') 420 READ ( l.J * ) TPC Listing 2 continued on page 144 142 April 1981 © BYTE Publications Inc Circle 97 on inquiry card. SYBEX BREAKS THE LANGUAGE BARRIER NTRODUl WM v . PA5CBC ■i Let the chips fall where they may. These two books on BASIC assure comprehension and competence. by Richard Mateosian teaches interactive game design and BASIC programming through thorough analysis of eight different kinds of computer games. Programs are presented in Microsoft BASIC with versions for PET/CBM, TRS-80 and APPLE II. 350 pp., 120 illustr., Ref. B245, $13.95 by I. P. Lamoitier provides the surest way of learning BASIC— actual practice. Graduated exercises, each containing a detailed explanation, flowchart and sample run, develop skill and competence rapidly. Applications include mathematics, business, opera- tions research, statistics and more. 256 pp., 194 illustr., Ref. B250, $12.95 Get in gear and accelerate your programming productivity with Pascal's power. )y Rodnay Zaks is a simple yet comprehensive guide to standard and UCSD Pascals: step-by-step presentation with exercises for beginners, complex concepts and extensive appendices for experienced programmers. An indispensable book for everyone who wants to learn Pascal programming. pp., 100 illustr., Ref. P310, $14.95 by lacques Tiberghien is an easy-to-read, easy-to-use dictionary containing all the features for most existing versions of Pascal (Standard, Jensen-Wirtli, OMSI, UCSD, HP1000, Pascal/Z). Over 180 entries, arranged alphabetically; each includes definition, description, syntax diagram, details of implementation, variations and examples. The perfect reference tool for any Pascal user. 500 pp., 150 illustr., Ref. P32C MAIL TO: SYBEX DEPT. B41 2344 SIXTH STREET BERKELEY, CA 94710 ONE ORDERS: INSIDE CA 415/848-8233 LL FREE OUTSIDE CA 800-227-2346 NAME ADDRESS. CITY Scientists and engineers involved in significant work have been delayed by having to reinvent algorithms for a new computer language. No more. by Alan Miller is a comprehensive collection of frequently used algorithms for scientific and technical applications programmed in PASCAL. This time saving book includes programs for curve fitting, fast Fourier transform, approximations, random number genera- tion, integrals, statistical techniques and more. 250 pp., 80 illustr., Ref. P340 □ $16.95 paper, □ $25.00 cloth YOUR FIRST COMPUTER by Rodnay Zaks 280 pp., 150 illustr., 2nd Edition, Ref. C200A, $7.95 MICROPROCESSORS: FROM CHIPS TO SYSTEMS by Rodnay Zaks 420 pp., 250 illustr., 3rd Edition, Ref. C201, $12.95 MICROPROCESSOR INTERFACING TECHNIQUES by Rodnay Zaks & Austin Lesea 464 pp., 400 illustr., 3rd Edition, Ref. C207, $15.95 PROGRAMMING THE 6502 by Rodnay Zaks 392 pp., 160 illustr., 3rd Edition, Ref. C202, $12.95 6502 APPLICATIONS by Rodnay Zaks 288 pp., 207 illustr., Ref. D302, $1-2.95 6502 GAMES by Rodnay Zaks 304 pp., 140 illustr., Ref. G402, $12.95 PROGRAMMING THE Z80 by Rodnay Zaks 620 pp., 200 illustr., 2nd Edition, Ref. C280, $14.95 PROGRAMMING THE Z8000 by Richard Mateosian 312 pp., 124 illlustr., Ref. C281, $15.95 THE CP/M HANDBOOK (With MP/M) by Rodnay Zaks 336 pp., 100 illustr., Ref. C300, $14.95 □ SEND ME YOUR FREE CATALOC STATE. ZIP ADD O$1.50/book UPS or □ 75 120) J. ZERO FORMAT ( A 1 ) WRITE ( 3 v 121) F R M A T ( -' I N P U T C H A R A C T E R F R N E . "' ) READCU 120) I ONE INITIALIZE TAPE TO ZERO HO 4 j>l vMTAPE TAPE(I)=0 CONTINUE KIT«0 TAPE LIST ROUTINE KT APE** 1 KIT»KIT+i DO 32 N»l yMTAPE I T APE CN)~I ZERO IF (TAPE (N) .EQ*0)G0T0 32 ITAPE(NXi:0NE CONTINUE W R I T E ( 3 >• 1 1 3 ) ( I T A P E ( I ) » I » 1 , M T A P E ) FORMAT (128A1) IF (KIT, ECU MIT) GO TO 99 RUN CONTINUE TPOTPC+1 T -TAPE CRT APE) + 1 D:i>Dnvrpo TAPE(KTAPE)~W 4.4 MEGABYTES FOR YOUR APPLE 1 ■ — • ■ jH^' Double-Sided, Double-Density 8-Inch Drive Capability is Here ... Now! The new LOBO DRIVES Model LCA-22 Double Density Floppy Disk Controller has been specifically designed to match your APPLE® to the new double-sided, double-density 8-inch floppy disk drives. Now, you can add up to four 1.1 Megabyte drives (4.4 Megabytes total) and realize all the power and potential of your APPLE computer. Completely Software transparent, the Model LCA-22 will plug into any chassis slot. You are no longer restricted to slot 7. And, the Model LCA-22 is fully compatible with 3.2. (3.3 DOS systems, PASCAL will be available soon.) LOBO's new LCA-22 Disk Controller and full line of field-proven, high-reliability disk drives (all LOBO products come with a one year, 100% parts/labor warranty) are available at computer retail stores nationwide. Stop in and see a demonstration at your local dealer today. See us at the NCC, booth 4211. drii/esr w INTERNATIONAL LOBO DRIVES INT'L 354 South Fairview Ave. Goleta, CA 93117 (805) 683-1576 I'm looking to expand my APPLE. Please send me more information on: □ Model LCA-22 Disk Controller □ Floppy Disk Drives D 5 1 /4-inch □ 8-Inch Name _ Address City □ Fixed Disk Drives D 5 1/4 -Inch □ 8-Inch □ 14-inch State Zip Phone (area code) NO FRILLS! NO GIMMICKS! JUST GREAT DISCOUNTS MAIL ORDER ONLY ATARI 800 Personal Computer System . . . $79900 NORTHSTAR Horizon II 32K Horizon II Quad Horizon II 64K Horizon Quad 64K . . . . 234900 279900 299900 339900 TELEVIDEO 912 920 74900 79900 HAZELTINE 1420 1500 1510 1520 79500 84900 104900 122900 0KIDATA Microline80 55900 SOROC Technology iq 120 69900 iq 140 99900 CROMEMCO System 3 . . . . Z2H 569500 799500 TELETYPE 43 94900 Acoustic Coupler 17900 DECwriter IV LA34 97900 TEXAS INSTRUMENT 810 Multi Copy Impact Printer 149900 We'll meet or beat any advertised prices! Most items in stock lor immediate delivery. Factory sealed cartons. Full manufacturer's guarantee. DATA DISCOUNT CENTER 135-53 Northern Blvd., Flushing, N.Y. 11354 Visa • Master Charge* N.Y.S. residents add SalesTax Shipping F.O.B. N.Y. Phone Orders Call 212-465-6609 clock „ JLIUUUULnJLILILIl CLOCK 4 CLOCK 3 CLOCK 2 CLOCK 1 CLOCK SIGNAL J~l J~~L 1_ TIME- Figure 5: Timing diagram for the four-phase clock. The signals shown here are generated by IC23 and 1C24 in figure 3a. Note that within the schematic of figure 3c, the inverted counterparts of clock 2 and clock 3 are also used. Text continued from page 138: • entering the DO-0054 command in- to the trainer (this begins program ex- ecution at hexadecimal location 0054). The value of R is displayed con- tinuously on the leftmost LED of the trainer. The microprocessor representation of the PTM is easier to implement than the hardwired version. Changes in the length of the tape or the max- imum number of program statements are relatively easy to make, but the microprocessor is very slow com- pared with the hardwired version. Subroutine RUN requires about 150 /is per cycle as compared with 2 lis for the hardwired version. A FORTRAN Version One of the most useful and com- prehendable representations of a PTM is one written as a high-level language program. Listing 2 is a source listing for an interactive FOR- TRAN program that can be used to simulate a PTM. The run section of this program follows the flowchart in figure 2. The program is stored in three ar- rays dimensioned W(2,64), D(2,64), and ADR(2,64). The maximum length of the tape is 128 characters. A shift is made in the subscripts to allow R=0 and TPC=0. Output characters for the tape are chosen by the user rather than being restricted to and 1. Program statements are entered as six-component vectors and can be readily changed. The most important variables are available interactively to the user. Summary We have implemented the Practical Turing Machine in three forms — as a hardwired circuit, a 6800 machine code program, and a FORTRAN pro- gram. We have found that the hard- wire version is the fastest but the most difficult to run or modify, and that the FORTRAN version is the easiest to modify but the slowest in execution. The microprocessor ver- sion is a compromise in both speed and utility. ■ Acknowledgments / would like to thank Tom Ainsworth for his help in the design of the hardwired version, Dr W ] Thompson for his guidance during the pro- ject, and Alice Glenn for her help in the preparation of the manuscript. The research for this article was supported in part by the United States Department of Energy. References 1. Arbib, M. Brains, Machines, and Mathematics. New York, McGraw-Hill Book Company, 1964. 2. Bernstein, J. "When the Computer Pro- creates." New York Times Magazine, February 15 1976. 3. Millen, J K. "A Universal Turing Machine." December 1976 BYTE, pages 114 thru 119. 4. Minsky, M L. Computation: Finite and In- finite Machines. Englewood Cliffs NJ: Prentice-Hall, 1967. 5. Munnecke, Thomas. "Designing a Univer- sal Turing Machine: a Software Approach." December 1979 BYTE, pages 26 thru 30. 6. Turing, A M. "On Computability with an Application to the Entscheidungproblem." Proceedings of the London Mathematical Society, Volume 42, 1936, pages 230 thru 265. 146 April 1981 © BYTE Publication! Inc Circle 100 on Inquiry card. For those special people who've stepped ahead with a mini-computer t t t i maxej maxBll Mini-Floppy Disk Maxell offers a way to stay ahead. A Maxell 5 1 /4" Mini-Disk will consistently let you maxi- mize the capability of your system today. And as your involvement with it grows, tomorrow as well. Maxell Mini-Disks are all made with the same exacting 100% certification and critical dependability of the Maxell 8" Floppy Disk. So you know your 5 1 /4" Maxell Mini-Disks meet or exceed the same ISO and Shugart specifica- tions industry requires. There are double density Maxell single and double- sided 5 1 /4" Mini-Disks for soft and hard sector systems. And 8" Maxell Floppy Disks for every disk drive config- uration. See your computer supply dealer or write to us for more information. If you are a computer products dealer, write for the growing opportunities Maxell Business Products Division offers you with our 8" Floppy and 5 1 /4" Mini-Disks. maxEll BUSINESS PRODUCTS DIVISION Maxell Corporation of America, Business Products Division, 60 Oxford Drive, Moonachie, N.J. 07074 Tel: 201-440-8020 System Notes A Relocatable Bootstrap for the Tarbell Disk Controller Hector M Smith 9852 Dandelion Ave Fountain Valley CA 92708 Some Z80 microprocessors do not work properly with the Tarbell disk -controller ROM (read-only memory). For example, Ithaca Intersystems recommends that the bootstrap program be relocated to high memory and that a power-on jump to it should be executed. You can make the program independent of memory location by using the Z80 relative-jump instruction. Listing 1 is a relocatable version of the Tarbell bootstrap loader. Relative jumps are included at hexa- decimal locations 0010 and 0016. A test bit instruction is located at hexadecimal 000E. The original 8080 code is shown in listing 2. In the code, at hexadecimal locations 000E and 000F, ORA resets the sign flag if the MSB (most significant bit) of INTRQ is 0. If this is the case, JP jumps to RDONE. Because the Z80 does not have a relative jump instruc- tion activated by a positive test, BIT 7, A is used to check if bit 7 (INTRQ) is 0. If it is, a jump relative to RDONE is executed. At hexadecimal location 0016, a jump relative to RLOOP and NOP was substituted for the original jump. The modified bootstrap (listing 1) can be located anywhere in memory. A jump to it will boot the CP/M operating system. ■ Listing 1: A Z80 relocatable bootstrap program for the Tarbell disk controller. The mnemonics are TDL Assembler. ADDR MACH LABEL ASY LANGUAGE COMMENTS CODE 0000 DB FC BOOT: IN WAIT WAIT FOR HOME. 0002 AF XRA A COMPLETE. 0003 6F MOV L,A SETL = 0. 0004 67 MOV H,A H&L = 0. 0005 3C INR A SET A = 1 . 0006 D3 FA OUT SECT SECTOR = 1. 0008 3E 8C MVI A.8CH READ SECTOR. O00A D3 F8 OUT DCOM O00C D2 FC RLOOP: IN WAIT WAIT FOR DRQ OR INTRQ 000E CB 7F BIT 7, A TEST BIT 7 0010 28 07 JRZ RDONE DONE IF INTRQ 0012 DB FB IN DDATA READ A BYTE OF DATA. 0014 77 MOV M,A PUT INTO MEMORY. 0015 23 INX H INCREMENT POINTER 0016 18 F4 JMPR RLOOP DO IT AGAIN 0018 00 NOP FILLS EMPTY SPACE 0019 DB F8 RDONE: IN DSTAT READ DISK STATUS. 001B B7 ORA A SET FLAGS. 001C CA 7D 00 JZ 07DH IF ZERO, GO TO SBOOT. 001F 76 HLT DISK ERROR, SO HALT. WAIT = OFCH SECT = OFAH DCOM = OF8H DDATA = OFHB DSTAT = OF8H sting 2: Original 8080 code before modification for the Z80 microprocesso 000E B7 OR A A 000F F2 19 00 IP RDONE 0016 C3 0C 00 JM P RLOOP 148 April 1981 © BYTE Publications Inc Circle 102 on inquiry card. Lifelines* The serious publication for the serious software user. March 1981 Vol. 1 Issue #10 From the Software Evaluation Group: A Review of the Configurable Busi- ness System Osborne/McGraw-Hill's General Ledger, a Tutorial by One of Its Authors. BASIC Comparisons: An Introduction to SBASIC.* Details on Volume 48 from The CP/M Users Group.* Some Biting Comments on the Indus- try from the Mysterious Zoso. Lifelines is the publication dedicated to keeping you up-to-date on happenings in the explosive micro- computer world. Lifelines specializes in news about software for CP/M* and similar operating systems. Lifelines does it with a guarantee of high level, in-depth analysis of software uses and capabilities. Lifelines does it with valuable information necessary to make intelligent software buying decisions. Lifelines does it with the latest information on The CP/M Users Group. Lifelines does it with thought provoking discussions on many of the more controversial issues facing computer users. How can you live without Lifelines? Subscribe Now! $18.00 for twelve issues: U.S., Canada, and Mexico. $40.00 for twelve issues: all other countries. $2.50 for each back issue: U.S., Canada, and Mexico. $3.60 for each back issue: all other countries. All orders must be pre-paid by check to: LIFELINES, 1651 Third Avenue, New York, N.Y 10028 — Checks must be in U.S. $, drawn on a U.S. bank. Or use your VISA or MASTERCARD. Call (212) 722-1700 'SBASIC is a trademark of Topaz Programming * CP/M is a trademark of Digital Research, Inc. The CP/M Users Group is not affiliated with Digital Research, Inc. ■^Ms^n l^M^^ft A Closer Look at the TI Speak & Spell Congratulations to Michael Rigsby on his article "Dissecting the TI Speak & Spell" (September 1980 BYTE, page 76). He is not alone in desiring an economical voice-output device for his computer, and the Speak & Spell is an excellent choice. Economy is one reason, and the circuitry of this device has features that make it potentially one of the most flexible and comprehensive speech syn- thesizers available. The problem is how to interface the Speak & Spell to a computer. Mr Rigsby 's approach is the first step, but it allows only a spelling computer, not a talking one. In order to achieve more, it is necessary to know something about the workings of the device. This information is difficult to obtain. Texas Instruments has not been very informative, although con- sidering the investment it has in speech technology this is perhaps understandable. Thus, the Speak & Spell is an irresistible challenge to the experimenter. Mr. Rigsby has, however, made one fundamentally incorrect assump- tion: the TI Speak & Spell is most definitely not based on the SN76477N complex-sound generator, nor does it store words, or even phrases, as in- dividual pulses in memory. As I will show, it uses an entirely different technique. The Heart of the Unit The TMC0281NL is a proprietary Texas Instruments integrated circuit that is virtually an entire digital signal processor, with timing and decoding circuits, a 10-pole digital lattice filter, and a D/A (digital-to-analog) con- Peter Vernon 31 Georgina St Newtown NSW 2042 Australia verter. All of this is contained on a tiny piece of silicon just 44 mils square. This is the heart of the speech synthesizer. Also on the board is the controller, the TMC0271NL, which is a member of the TMS-1000 microprocessor family. The TMC0271 shares the same basic architecture as the TMS-1000 used in TI's calculators, but it has been modified to enhance its BCD (binary-coded decimal) arithmetic capabilities. It also has an expanded instruction set and an out- put multiplexer to reduce the number of pinouts required in its role as a controller for the speech synthesizer IC (integrated circuit). The Speak & Spell is an irresistible challenge to the experimenter. As Mr Rigsby guessed, the other two integrated circuits on the board are high-density ROMs (read-only memories). The TMC0350 family are 128 K-bit ROMs, organized as 16 K by 8 bits. They incorporate an inter- nal 18-bit address counter/register and two 8-bit output buffers, with the four high-order bits of the address driving a l-of-16 device-select decoder and the other 14 bits address- ing the ROM array directly. Linear Predictive Coding The circuitry is only part of the story. The real secret of the Speak & Spell and other Texas Instruments speech-synthesis devices is a tech- nique called LPC {linear predictive coding). This technique makes it possible to encode a complex speech waveform with relatively little data. A speech signal is highly redundant, made up of a few basic waveforms that are repeated to produce speech sounds. Essentially, LPC eliminates the redundancy inherent in the speech signal and retains only the data re- quired to drive the speech syn- thesizer. The TMC0281 can be thought of as an electronic model of the human vocal tract. The data input is a description of the filter parameters necessary to model the vocal tract as its characteristics change over time. Codes for twelve synthesis par- ameters are stored in the ROMs. These parameters are ten filter co- efficients, and pitch and energy infor- mation. The filter parameters are derived from samples of actual speech and are encoded by a complex mathematical algorithm that makes it possible to predict a speech waveform based on information derived from previous waveforms. Because of the finite-time response of the human vocal tract, only a fixed number of speech sounds can follow a particular vocalization. To produce speech, the controller specifies the starting point of a string of data stored in the ROMs. The ROM output provides the pitch, amplitude, and filter parameters from which the synthesizer constructs the speech waveform. The input to the filter is either a periodic or random sequence of pulses. A random sequence of pulses is used to recreate unvoiced sounds, 150 April 1981 © BYTE Publications Inc Circle 103 on inquiry card. The One Printer Solution for the Two Printer Problem. HIGH SPEED DATA PROCESSING The new Dual-Mode 200 brings speed and un- compromising print quality to business and pro- fessional applications. Financial statements, inventory reports, la- bels and more are printed at data processing speeds from 165 cps to 250 cps. Fully adjustable tractors and a friction feed platen provide precise forms handling for pin- feed and single sheet paper. Complete "Dot Control" graphics is standard with resolution to 120 x 144 dots per inch. Interfacing is easy with both E.l.A. RS-232C serial and an ASCII parallel port. LETTER QUALITY WORD PROCESSING The Dual-Mode 200 also features letter per- fect print you will be proud to use for business letters and reports. Letter Mode speeds range from 42 cps to 60 cps. The standard Titan 10 pitch font is comple- mented by an array of optional fonts including Elite 12 pitch, italics, proportionally spaced, OCR-A, scientific and foreign character sets. Up to 12 font selections may be stored in the printer and interchanged while printing. The Dual-Mode 200 accepts standard daisy- wheel print commands for word processing sys- tem compatibility. It's the perfect solution for the two printer problem. The Dual-Mode 200 Printer for the one printer office. Call or write today for complete specifications 2301 Townsgate Road, Westlake Village, CA91361 , (805)496-1990 Electronics Corporation DOTS DO IT BETTER™ ATTENTION DEALERS SUPERBRAIN & COMPUSTAR We're the West's largest distributor of Intertec products to dealers. We offer hardware and software sup- port and our own version of program, called Comdex . We sell Superbrains world-wide and Compustars in our region. Our prices are the best! Intertec's CARE C " •SUPERBRAIN •COMPUSTAR •HARD DISCS 64k, QD Models Models 10. 15. 20, 30,40 10,32&96mb •INTERTUBE III -EMULATOR Plus a full line of printers and peripheral equipment, including MPI, NEC, QUME, C.ltoh, Anadex, Tl, Vista and others. SERVICE Rapid turnaround on parts and module replacement, and repair in our trained service department. OE We have the best prices on Intertec products to the OEM market, and we make available the same fast service on parts, modules and war- ranty repairs. SOFTWARE We're more than order-takers. Our software specialists stand ready to give our dealer network the support you want and need to make you successful. Our Superbrain software is the best and you'll like our prices. C M BASIC BASIC Accounts Receivable X X Accounts Payable X X General Ledger X X Payroll X X Restaurant Payroll X Job Costing X X Mailing List (NAD) X X Restaurant Menu Costing and Inventory X Client Billing X Inventory X X LANGUAGES C Basic M Basic Pascal (UCSD) Fortran Cobol UTILITY PROGRAMS Pearl, Q Sort and Link 80 WORD PROCESSING Magic Wand, Word Pro, Word Star, Data Star PEACHTREE SOFTWARE - BUY ONE PROGRAM OR ANY FOR ORDERING CALL TOLL FREE 1-800-426-2963 PHONE (206)453-9777 TELEX: 152 556 TAC I* Yy A Division of Computer Marketing Corporation INTERNATIONAL 11058 Main, Suite 125, Bellevue, WA 98004 such as "[" or "s," while a periodic se- quence creates voiced sounds such as "a." The pitch information either varies the frequency of the periodic pulses or, if all the bits are zero, selects random noise as the input to the lattice filter. An amplification fac- tor is also input to the synthesizer and adjusts the amplitude of the excita- tion source to produce sounds of varying intensity. The lattice filter of the synthesizer has ten stages. Each stage carries out two multiplications and two addi- tions on its two digital inputs before passing the results backward and for- ward to its neighbors. The operations of the ten stages are carried out se- quentially, as are the operations within each stage. Through careful consideration of timing and the use of a pipeline approach, only one adder and one multiplier are needed to carry out the mathematical opera- tions. Each separate arithmetic opera- tion requires only 6 fis. Figure 1 is a block diagram of the basic elements of the TMC0281. The multistage lattice filter uses the parameters K x thru K„ to digitally filter the amplified excitation signal, and passes its output to a D/A con- verter connected to the speaker. The coefficients of the filter are up- dated approximately every 20 ms. However, because of the redundan- cies in speech patterns, a complete set of parameters is not always required. Sections of the data stream may be replaced by a single "repeat" bit, cut- ting the data required to control the filter from a maximum of 49 bits to a minimum of 4, thus conserving memory space. During speech the TMC0281 ac- cesses the ROMs directly until it receives an end-of-phrase command and returns control to the TMC0271 controller. Five lines are used to transfer data and commands within the system. One of these lines is the processor data clock, which deter- mines when the data on the other four lines is valid. These are the five lines mentioned by Mr Rigsby. Timing Timing for the synthesizer is based on a 50 Hz frame rate — so a new speech segment is read from the ROM every 20 ms. The speech patterns cod- ed in the ROM are sampled at a rate of 10 kHz, which corresponds to the maximum bandwidth of speech — 5 152 April 1981 © BYTE Publications Inc Circle 104 on inquiry card. Introducing the Butterfly' u switch. The first Key Tronic capacitive ^^^^^key board with linear leel. j^^. For years our have been using tactile customers successfully fool, however, had input from field that a lot ' of you like linear feel. Key Tronic now offers both. We want to bo your keyboard supplier. This patented solid-state keyboard uses the same electronics as our proven tactile design. You slill get N-key rollover (a musl in any medium to high speed data entry environment) at no extra charge. The same double-shot molded keytops with over 20,000 legends and over 300 shapes are still avaiU able from thy/leader. J~ Please ceil or write a for further informa-/ tion. Yoti'll be glad ycu did. V ^ key tronic INTERNATIONAL KEYBOARDS ' I'.O. ItOX 14687 SPOKANE, WASHINGTON 99214 U.S A. PHONE (509) 928-8000 — TWX 510 773-1885 Circle 105 on inquiry card. BYTE April 1981 153 Circle 106 on Inquiry card. The reachable star. Under $2001 We've modem with excl acoustic cups, crystal oscillator, and built-in diagnostics and indicators. It's packaged inside an attractive in- jection molded case...and we stand behind the STAR with two year warranty! STAR models are available that interface directly with RS232 machines such as APPLE, ATARI, and NORTH STAR or IEEE 488 machines such as the PET, and that operate with either U.S. or European frequencies. :; WHITE 1 ■ ■ ' . ■ ' ■■•■! NOISE PERIODIC I I I I PULSES UNVOICED VOICED* PITCH AMPLITUDE LATTICE FILTER VOCAL TRACT MODEL SPEAKER D/A CONVERTER -< FILTER COEFFICIENTS Figure 1: Block diagram of the heart of the TI Speak & Spell— the Texas Instruments TMC0281NL integrated circuit. The TMC0281NL is a proprietary circuit that is virtual- ly an entire digital signal processor and can be thought of as an electronic model of the human vocal tract. It includes timing and decoding circuits, a 10-pole digital lattice filter, and a D/A converter. Speech synthesis takes place through a process called LPC (linear predictive coding), which makes it possible to encode a complex waveform with relatively little data. Either pseudo-random noise (for unvoiced sounds) or periodic pulses (for voiced sounds) are amplified and fed to the lattice filter, which models the vocal tract in accordance with coefficients stored in two external 16 K by 8-bit ROMs (read-only memories). A maximum of 49 bits is needed to specify each sound pattern, which is updated every 20 ms. This results in an overall data rate of 2400 bps (bits per second). The TMC0281NL is controlled by a TI TMC0271 microprocessor, a specialized member of the TMS-1000 microprocessor family. kHz. (The maximum bandwidth for telephone-quality speech is 3.5 to 4.5 kHz.) An 800 kHz oscillator is divid- ed by four to produce the major system clock. This four-phase clock controls the transfer of data within the system. The individual bit pat- terns in each 20 ms frame are clocked into the synthesizer at a rate cor- responding to the sample frequency of 10 kHz. It is this clock which pro- duces the 0.1 ms pulses measured by Mr Rigsby. A maximum of 49 bits is needed to specify the sound pattern that will be produced every 20 ms. This is an overall data rate of about 2400 bps (bits per second). One hundred seconds of speech time thus requires the storage of 240,000 bits of infor- mation, which corresponds well with the 256,000 bits of storage provided by the two TMC0351 ROMs. Capabilities and Challenge Because the Speak & Spell reconstructs speech sounds from a constant-excitation signal filtered under digital control, it is potentially capable of reproducing any sound at all. The challenge for the ex- perimenter is to determine what in- formation needs to be input to create a particular sound. Trial and error seems to be the only approach. With much work it would be possible to determine which combinations of data are needed to produce each phoneme of the English language. (All words are made up of combina- tions of particular sound units called phonemes. About 42 phonemes are used in the English language.) These phoneme patterns could be stored in memory and arranged to produce any word. At 49 bits per phoneme and 42 phonemes, only 2058 bits are re- quired. The problem is, of course, to find the right bits. Perhaps the best place to start would be the connector provided for the attachment of expansion modules. The module-select key on the keyboard of the Speak & Spell is used to signal the controller that an expansion module is in place and that it should instruct the synthesizer to access this module rather than the ROMs on the main circuit board. By using this signal it is possible to force the synthesizer to accept data that is input on the module connector. The system clock can be used to govern the rate of this data input. Experi- menting with this approach produces a weird and wonderful series of sounds. At present, my computer (an Exidy Sorcerer) can only grunt and squeak, but after all, that's how we all started IB 154 April 1981 © BYTE Publications Inc ,0 $r SSS ANSI 'ee STANDARD f CDTEAN IV WITH RATfCC DCR CD/M TOGETHER AT LAST SSS FORTRAN & RATFOR are the critic's choice! The SSS FORTRAN compiler is fast, efficient, and complete (full 1966 ANSI standard with extensions). The RATFOR compiler compiles into FORTRAN allowing the user to write structured code while retaining the benefits of FORTRAN. Together they form an incredible team! SSS FORTRAN Specifics SSS FORTRAN makes full FORTRAN IV available to microcomputers. SSS FORTRAN meets and exceeds the ANS1 1966 FORTRAN standard. The compiler supports many advanced features not found in less complete implementations, including: complex arithmetic, character variables, and functions. SSS FORTRAN will compile up to 600 lines per minute! Recursive subroutines with static variables are supported. ROMable ".COM" files may be generated. FEATURES Code generation: ROMable ".COM" files or intermediate code files (saves disk space). External routines may be called. Data types: Byte, integer, real, double precision, complex, logical, charac- ter and varying length strings. Operations: All standard operations plus string comparisons, assignments, and .XOR. Constants: Hexadecimal, decimal, and character literals with features to imbed control characters. Statements: ANSI 1966 standard with multiple statement lines, state- ments may end with a ' ;'. Controls: Map, List, and Symbol table output options. I/O: Read, Write, Append, Rewind, Close, Delete, Rename, Search, seguencial and Random I/O on disk files. Supports all CP/M devices. The User can add device handlers to use custom I/O devices. Errors: Over 200 distinct compiler error messages, precision and illegal instruction warnings during execution. Interrupts: FORTRAN programs may be interrupted at any time: the stack pointer is always preserved. • • D E ATLCIM3 • m SSS RATFOR RATFOR is a preprocessor that compiles to SSS FORTRAN. SSS RATFOR allows the use of contemporary loop control and struc- tured programing techinques. SSS RATFOR is similar to FORTRAN 77 in that it supports such things as: REPEAT . . . UNTIL WHILE IF . . . THEN . . . ELSE Begin End Brackets Macro Defines SSS RATFOR is supplied with source code. The source code is distributed in both RATFOR and SSS FORTRAN. Not only does this prevent obsolescence, but allows the user to add enhance- ments as desired. System Requirements & Prices SSS FORTRAN requires a 32k CP/M system. Z80 only. SSS FORTRAN with RATFOR: $325.00 SSS FORTRAN alone: $250.00 RATFOR alone: $100.00 (Sold only with valid SSS FORTRAN license) CP/M Formats: 8" solt sectored, 5" Northstar. 5" Micropolis Mod II, Vector MZ, Superbrain DD/OD All Orders and General Information: SUPERSOFT ASSOCIATES P.O. BOX 1628 CHAMPAIGN, IL 61820 (217) 359-2112 Technical Hot Line: (217) 359-2691 (answered only when technician is available) •CP/M REGISTERED TRADEMARK DIGITAL RESEARCH SSS FORTRAN is the copyright ot Small Systems Services. Urbana. Illinois SuperSoft First in Software Technology BYTE April 1981 155 EAST COAST OFFICE flMEG A Sales Company call Toll Free 1-800-556-T586 2nd SPECIAL OF THE MONTH!! PRINTER INTERFACES: Apple Interface & Cable 890, RS»232-»TO, IEEE S55, TRS»80 Cable S35 ATARI 800 »T59oo INTERTEC SUPERBRAIN 32K - »S449oo 64K - SS64900 qd - S319500 NorthStar Horizon II 32K Quad. Dens. ®29T5 00 NEC Monitor »21900 Radio Shack 16K Level II Model 3 »8T5oo Radio Shack 64K Model 2 S3449oo T- I Atari 400 8K - »399oo 16K - »49900 Anadex DP-9500 »1249oo T I I I I SOROC 120 - »630 140 - »949 available in limited quantities Televideo 912C - »6T900, 920C - »T3900 4. Stock shipments shipped usually same day or next day. 5. All equipment factory fresh with manufacturer's warr. 6. STo hidden charges - We live by our published prices. OMEGA Sales Co - East Coast - 12 Meeting St. Cumberland, RI 02864 Tel 1-401-T22-102T Prices subject to change without notice. 156 BYTE April 1981 WEST COAST GRAND OPENING!!! OMEGA. Sales Company call Toll Free 1-800-S35-3581 GRAND OPENING SPECIAL OF THE MONTH!! OKIDATA MICROLINE DIABLO 630 $199500 (TRACTOR $200) APPLE 11+ 48K-®1150°° "C. ITOH STAR WRITER 25 PARALLEL OR SERIAL »119500 Mnr NEC Spinwriter 5510-5530 »S39500 (TRACTOR S200) Apple Disk Drive DOS 3.3 W/CONTROLLER »54500 OKIDATA MICROLINE-80 »469°° BASE II »649°° CBM CALL FOR PRICE HAZELTINE 14SO #T99 £ 1. TWO LOCATIONS TO SERVE YOU BETTER. 2. NO SURCHARGE FOR CREDIT CARDS. 3. WE ACCEPT C. O. D.'S. OMEGA Sales Co - West Coast - 3353 Old Cone jo Rd #102 Newbury Park CA 91320 Tel 1-805-499-36T8 Circle 61 on inquiry card. BYTE April 1981 157 Clubs and Newsletters Zips 00000—10000 1. Syntax ZX80 2. The Harvard Group, Bolton Rd, RD 2, Box 457, Harvard MA 01451 3. Ann Zevnik, Editor, (617) 456-3661 5. News about the Sinclair ZX80 microcomputer. 1. Gosub TRS-80 Users Group 2. POB 712 Worcester MA 01613 3. Jim Mercanti, (617) 845-1851, (617) 458-7263 4. Gosub TRS-80 Users Group Buffer 5. Noncommercial. 1. TRUGEM (TRS-80 Users Group of Eastern Mass- achusetts) 2. 3 Driscoll Dr, Fram- ingham MA 01701 3. Ronald M Egalka, Secretary, (617) 877-4520 4. The TRUGEM Newsletter 5. TRS-80 hardware and software; peripherals from Radio Shack and independents; Programs Exchange Library (non- commercial); demonstra- tions and sales of com- mercial hardware and software encouraged. 1. New England Computer Society 2. POB 198 Bedford MA 01730 3. Bob Waite, President (617) 448-6351 home; (617) 897-3221, ext 2499, work 4. NECS Newsletter 5. User Groups: PET, Apple, 6800, Digital Group, and TRS-80. CBBS (Computerized Bulletin Board System), (617) 864-3819. 1. The Boston Computer Society DIRECTORY The following is the fourth BYTE Clubs and Newsletters Directory. The directory was compiled from information sup- plied by the various clubs listed. A form was sent to all clubs and newsletters listed in the third directory requesting up-to- date information. If the form was not returned, we deleted the club from the fourth directory. In addition, the listing was cor- related with back issues of the magazine and materials on file in the BYTE offices. If information is missing in one or more categories, it means the data was not provided. We will be keep- ing the file available and updating it for the next directory; so, if there are errors, omissions, or if you have a new club that has just been formed, send the information to Charley Freiberg, Clubs and Newsletters Editor, BYTE Publications Inc, POB 372, Hancock NH 03449. The listing follows this form: 1. Name of organization or name of publication; 2. Mailing address; 3. Contact person and telephone number; 4. Newsletter or publication; 5. Special interests. 2. 3 Center Plz, Boston MA 02108 3. (617) 720-0597 4. The Boston Computer Society Update (an enor- mous publication with nationwide industry ex- clusives and news of New England) 5. User Groups: PET, Sorcerer, OSI, North Star and others. Subgroups: education, business applications, Pascal and beginner tutorials. 1. Classroom Computer News 2. POB 266, Cambridge MA 02138 3. Lloyd Prentice, (617) 787-0420 5. This bimonthly newslet- ter is interested in educa- tion, curriculum develop- ment, and related topics. 1. Technical Education Research Centers 2. 8 Eliot St, Cambridge MA 02138 3. Robert Tinker, Director or Susan Warner-Mills, Assistant, (617) 547-3890 4. Hands On!(A Forum for Science and Technology Educators) 5. Applications to educa- tion, especially science. 1. RICH (Rhode Island Computer Hobbyists) 2. POB 599, Bristol RI 02809 3. Emilio D Iannuccillo 4. Yes 5. We are an active group dedicated to keeping abreast of current tech- nology, plus lending a hand to each other regarding hardware and software. We also give help and advice to new- comers into the world of microprocessors . 1. PIE (PET Information Ex- change) 2. 27 Leicester Way, Pawtucket RI 02860 1. SNAC (Southern New Hampshire Apple Core) 2. Computerland of Nashua, 419 Amherst St, Nashua NH 03060 3. Don Fairchild, Treasurer, (603) 434-5626 4. S.N.A.C. 5. This group is involved in all aspects of home com- puting using Apple systems. 1. Manchester Users Group 2. 346 S Taylor St, Man- chester NH 03103 3. Scott, (603) 624-0089 4. Yes 5. TRS-80s. 1. Southern Maine TRS-80 Group 2. 15 Mountain View Rd, Cape Elizabeth ME 04107 3. Douglas Stewart, (207) 767-2351 4. Byte Babble 5. TRS-80s. 1. Doctor's Computer Club 2. 42 E High St, East Hamp- ton CT 06424 3. Dr Aziz Ghaussy, (203) 267-2400 4. Medical Computer Jour- nal Newsletter 5. Application of computers in medical practices. 1. The Pocket Computer Newsletter 2. POB 232, Seymour CT 06483 1. Computers in Psychiatry/ Psychology 2. 26 Trumbull St, New Haven CT 06511 3 Marc D Schwartz, MD, Editor, (203) 562-9873 5. This publication is for professionals interested in the use of computers in their work. 1. Connecticut Computer Club 2. 18 Ridge Ct W, West Haven CT 06516 3. Leo Taylor, Secretary 4. CCC Newsletter 5. We have two talks per meeting; generally one on software and one on hardware. The club does not specialize in any one machine. 1. API Market Newsletter 2. POB 5314, Mt Carmel CT 06518 3. Raymond C Jordan, (203) 288-0283 158 April 1981 © BYTE Publications Inc Circle 107 on inquiry card. Cor vus Lowers the Price of Admission to the Winchester Club ■ Here's the price breakthrough you've been waiting for on Winchester disk systems. It's our new5'i-inch 5-million byte Winchester that adds cost effective mass storage to over 15 of the most popular microcomputers. Now everyone can enjoy the improved reli- ability, increased storage capacity, and faster speed of sealed-environment Winchester technology. You can start with 5 million bytes, then expand the system with up to three add-on drives of 5. 10, or 20 million bytes. Our 5 million byte system has all of the advanced features of the larger capacity Corvus systems, including our low cost MIRROR back- up and multi-user CONSTELLATION network that allows up to 64 computers to share the Corvus data base and peripherals such as printers. Want the full story? Contact your local computer store. \I V i ''*■•. in ■ PRICE: S3750 WHEN: NOW! WHERE: YOUR LOCAL COMPUTER DEALER ** CORVUS SYSTEMS * * 5 MILLION BYTE MICRO WINCHESTER DISK SYSTEM J t ' ' «• \ - For Apple TRS-80 LSI-11 Zenith SuperBrain Pet S-100Bus Alpha Mi" ■ PS \ CORVUS SYSTEMS 2029 OToole Avenue San Jose, California 95131 408/946-7700 TWX: 910-338-0226 Clubs and Newsletters, 1. Amateur Computer Group of New Jersey 2. 1776 Raritan Rd, Scotch Plains NJ 07076 3. Sol Libes, (201) 277-2063 4. ACG-NJ News 5. User Groups: 8080/Z80, 6800, KIM-1, TRS-80, PET, CP/M, 1802, S-100, Apple, and Pascal. We also have software libraries and tutorials. 1. OSI Users Group 2. 4 Swimming River Rd, Lincroft NJ 07738 3. Bob Childs, (201) 747-8888 1. Data Processing Club 2. c/o Dennis M Lloyd, Business Studies Division, Gloucester County Col- lege, Tanyard Rd, Sewell NJ 08080 3. (609) 468-5000, ext 242 4. Interested in microcom- puter programs inside and outside of the classroom. Zips 10000—20000 1. New York Amateur Computer Club 2. POB 106, Church Street Sta, New York NY 10008 3. Garry Sawyer, (212) 864-4595. 4. New York Amateur Computer Club News- letter 5. Anything to do with computers. 1. Computer Careers News 2. 135 W 50th St, New York NY 10020 3. Connie Winkler, Editor, (212) 582-9617 5. Careers publication for processing professionals. 1. Feedback From Fujitsu 2. c/o Ruder & Finn Inc, 110 E 59th St, New York NY 10022 3. Darrell J Aherin, (212) 593-6317 5. News of the Japanese • TRS-80 • APPLE 2 • ATARI • SCORCERER • >q h m w H CL. • • H 06 so u en K , do u © <-> OS o <-> (13 • m If FREE CATALOG ha • 25 < over 150 items • N ORDER TOLL FREE | u (800) 327-7172 • on £ §! IN FLORIDA (305) 862-6917 <"> 'nuf said s 33 * o e m op 50 (A m OS 33 H • • 06 "0 m UJ H 06 u o H 06 33 O on 1 op TRS-80 • APPLE 2 • ATARI • SCORCERER o BOX 3435 INTERNATIONAL A DIVISION OF SCOTT ADAMS. INC LOIMGWOOD.FLA. 32750 computer, telecom- munications, and elec- tronics industries. 1. Lifelines 2. 1651 Third Ave, New York NY 10028 3. Mary Anna Feczo, (212) 722-1700 5. This publication is for CP/M users. 1. Association for Com- puters and the Humanities 2. Queens College, Flushing NY 11367 3. Joseph Raben, (212) 520-7407 4. ACH Newsletter 5. Humanities applications. 1. Small Computer News 2. Edwards Publications, 78-56 86th St, Flushing NY 11385 3. (212) 441-4082 1. D G Independent User's Group 2. POB 316, Woodmere NY 11598 3. Lloyd Kishinsky, (516) 374-6793 4. Bridge 5. Digital Group computers. 1. Long Island Computer Association 2. 3788 Windsor Dr, Bethpage NY 11714 3. A M Stone, Editor, (516) 731-1649 4. The Stack 5. User Groups: S-100, TRS-80, and 6502. 1. Digiac Corporation 2. 175 Engineers Rd, Smithtown NY 11787 3. James D Gobetz, Presi- dent, (516) 273-8600 4. MAPS Digest 5. For MP/M users. 1. CAMS (Capital Area Micro Computer Society) 2. POB 348, Ridge Rd, RD #1, Scotia NY 12302 3. Stanley L Mathes, (518) 372-3767 4. Occasional — Circle 108 on inquiry card. Subgroups for Apple (associated with Interna- tional Apple Corps), TRS-80, S-100, and other groups. 1. Sphere Microcomputer Group 2. 2 Tor Rd, Wappingers Falls NY 12590 3. Jeffrey Brownstein, DDS, (914) 297-3950 4. Sphere Newsletter 5. 6800 microcomputers. 1. CHIP-S Microcomputer Club 2. POB 504, Syracuse NY 13201 1. Mohawk Valley Microcomputer Club 2. 706 Lee St, Rome NY 13440 3. Rich Weaver 4. Micros Along the Mohawk 5. Several special interest groups: 6800, 8080/Z80, and beginners. 1. RAMS (Rochester Area Microcomputer Society) 2. POB 90808, Rochester NY 14609 3. Erwin Rahn, (716) 473-3184 4. Memory Pages 5. Special interest groups: UFORTH (University of Rochester FORTH) and 6800/6809/68000. Users groups: North Star and CP/M. 1. Monroeville Apple Users Club 2. Dr G J Harloff 3. 579 Carnival Dr, Pitts- burgh PA 15239 1. Central Pennsylvania Computer Club 2. 3263 Bull Rd, York PA 17404 3. Cletus Hunt III, (717) 764-4977 4. Data Dump 5. Special interests: SS-50 bus and TRS-80 systems. 1. Wyoming Valley TRS-80 Club If you write software, write Digital Research. bring your products to market. Independent Software Vendors (ISV's) are the key to solving the software crunch in the 1980's. To help you bring your products to market, Digital Research introduces the ISV Support Plan — designed to assist you in: Developing Your Product D With the fast and powerful PL/I-80™ Programming System □ ISV Seminars covering high level applications programming retting Esta Your Market ISV Seminars cover: □ Designing a marketing strategy □ Advertising □ Writing Manuals □ Assuring software security □ Supporting and updating products On-Going Support Includes. □ Legal and technical information □ Distribution channels □ Printing facilities □ Free product listing in our Applications Software Catalog s the world s largest software marketplace - — the GP/M® customer base. So why do it alone? Write Digital Research. We'll send you our free brochure detailing the ISV Support Plan. ED DJGiTflL RESEARCH' P.O. Box 579 Pacific Grove, CA 93950 (408) 649-3896 TWX 910 360 5001 WTTTTT Visit us at the W heNCC Circle 109 on inquiry card. BYTE April 1981 161 Clubs and Newsletters, 2. 302 Wyoming Ave, Kingston PA 18704 3. Art Prutzman, (717) 287-1014 5. Special interests: TRS-80 uses and modems. 1. Delaware Valley Com- puter Society 2. POB 651, Levittown PA 19058 3. Howard Kalodner, (215) 742-6612 4. DVCS Newsletter 5. TRS-80 users group. 1. PACS (Philadelphia Area Computer Society) 2. POB 1954, Philadelphia PA 19105 3. Dick Moberg, Eric Hafler; Hot line (215) 925-5264 4. The Data Bus 5. Users groups for all major microcomputers, courses on languages, computers for children, and other groups. Zips 20000—30000 1. Buss: The Independent Newsletter for Heath Company Computers 2. 325-B Pennsylvania Ave SE, Washington DC 20003 3. Charles Floto, (202) 544-0484 5. News on items that are hardware- and software- compatible with Heath Company computers and Zenith Data Systems. 1. Battery Lane Publications 2. POB 30214, Bethesda MD 20014 3. Eric Balkan, (301) 770-2726 4. Computer Consultant 5. Information of interest to free-lance and corporate consultants. 1. Washington DC CP/M Users Group 2. 7315 Wisconsin Ave, The WORKSHEET Problem-Solving Language Want to play "What-if"? Want to do Real Estate Analysis, Family Budgeting, Taxes, Company Cash Flow; want to simulate complex and interrelated processes'? WORKSHEET is a powerful language designed for the purpose of writing programs to solve these and all other problems that involve a row-column "spreadsheet". Even novice programmers are solv- ing complicated problems on the first day! WORKSHEET is not a hybrid text editor or a toy. It is a complete, self-documenting model-building system. List the assumptions that went into your budget with the SHOWF1L program — even the boss will understand! Change the assumptions, the relationships, or the data, and produce a new spreadsheet, neatly captioned, in minutes. Model too big to fit on a single page? Format it dynamically — one page of 12 (or any number) columns, or 2 pages of 6 columns, or whatever tells your story best. Conditional evaluation of a variable? Reference to variables in different rows, several columns back? No problem! Sample models include portfolio valuation, real estate evalu- ation, iterative solution of a Diophantine equation, family budget, product profit based on exponentially damped growth of sales. Use it for tough, professional jobs — it's the only CP/ M modeling system that can handle them! Requires 48K CP/M system and Microsoft Basic . C Basic or North Star Basic running under CP/ M with Matchmaker 11. WORKSHEET Language disk (5" or 8" CP/ M) $199.95 (specify version) 80-Page Manual only $ 19.95 The SoHo Croup 140 Thompson St., Suite 4-B New York, NY 10012 Note: CP. M, Microsoft, and North Star arc registered trademarks of Digital Research. Microsoft, and North Star Computers, respectively. Washington DC 20014 3. Winston Riley III, (301) 986-1234 5. Public-domain software exchange, review of operating systems, languages, and packages. 1. WACS (Washington Amateur Computer Society) 2. 4201 Massachusetts Ave, #168, Washington DC 20016 3. Robert Jones, Director 4. ]WACS 5. Interested in I/O Selectric conversions; inexpensive terminals and personal systems; 9900, 6800, 8080/Z80 hardware and software. 1. Washington Apple Pi 2. POB 34511, Washington DC 20034 3. Bernie Urban, (301) 229-3458; club phone (301) 468-2305 4. Washington Apple Pi 5. Education, medical, Pascal, assembly lan- guage, games, helping neophytes in computer programming. 1. TI Programmable Calculator Club 2. 9213 Lanham Severn Rd, Lanham MD 20801 3. Maurice E T Swinnen, Editor 4. TIPPC Notes 5. All AOS system pro- grammable calculators. 1. PEEK(65) 2. POB 347, Owings Mills MD 21117 3. Al Peabody, (301) 268-0561 5. This is a journal for OSI users. 1. CHUG (Capital Heath Users' Group) 2. POB 341, Fairfax VA 22030 3. Dale Grundon, Secretary 4. >CHUG 5. Interested in all Heath computers and related equipment. 1. AMRAD (Amateur Radio Research and Develop- ment Corporation) 2. 1524 Springvale Rd, McLean VA 22101 3. Paul L Rinaldo, (703) 356-8918 4. AMRAD Newsletter 5. Special interests: amateur radio and computers, computers and com- munications devices for the deaf, amateur com- puter networking. 1. WAKE (Washington Area KIM Enthusiasts) 2. 5112 Williamsburg Blvd, Arlington VA 22207 3. Ted Beach 4. Monthly 5. KIM and other 6502 single-board computers. 1. The Microcomputer In- vestors Association 2. 902 Anderson Dr, Fredericksburg VA 22401 3. Jack M Williams, (703) 371-5474 4. The Microcomputer In- vestor 5. Use of microcomputers to assist in making and managing investments. 1. Delmarva Computer Club 2. POB 36, Wallops Island VA 23337 3. Jean Trafford, (804) 824-3400 4. Peek-n-Poke 5. Special interests: 6502 processors, computer aids for the handicapped, education, business, and entertainment programs. 1. Tidewater Computer Club 2. 677 Lord Dunmore Dr, Virginia Beach VA 23464 3. C D Yeoman, (804) 420-6379 4. Hard Copy 1. Triad Heath Users Group 2. 424 Cliff dale Dr, Winston-Salem NC 27104 3. Hughes Hoyle, (919) 378-1050; Steve Minor, (919) 765-7717 162 April 1981 © BYTE Publications Inc Circle 110 on inquiry card. • Upgrade 8 bit systems All boards assembled & tested Here's the nucleus of a truly exceptional S-100 system: 1. 16 bit/8 bit Dual Processor (w/6 MHz 8088) 2. System Support 1 3. Disk 1 DMA Floppy Disk Controller (w/BIOS for CP/M * 2.2) 4. 32K of fast static RAM (w/IEEE 24 bit extended addressing) 5. Sorcim's powerful PASCAL/M *-8086 software on disk 6. Digital Research's CP/M *-86 software on disk 7. I/O and Disk Controller cables, plus full documentation on all hardware and software * PASCAL/ M is a trademark of Sorcim: CP/M is a registered trademark of Digital Research Total Package Price: $2495 - ORDER BEFORE MAY 1ST AND WE'LL ADD AN EXTRA 32K OF STATIC RAM FREE ! DON'T MISS OUT! AVAILABLE AT FINER COMPUTER STORES, OR ORDER DIRECTLY FROM US. omouPro OAKLAND AIRPORT, CA 94614 (415) 562-0636 ELECTRONICS Terms: Calilornians add tax. Allow for shipping (excess refunded). VISA and Mastercard orders call i415) 562-0636, Circle 111 on inquiry card. ude street address lor UPS BYTE April 1981 163 WESTICO... Because getting good software fast is hard. To get your software tomorrow, call Westico todav. (203) 853-6880. Westico understands your micro- computer software needs. We know you want a good selection of soft- ware without the hassle of hunting all over for it. , .We know you want it f ast . . . And we a Iso know you wa nt a product Packed by service. With Westico you get all three. We have an extensive list of guality software products for the serious microcomputer buyer — accounting, professional time ac- counting, text processing, planning and analysis, telecommunications, data management, development^ tools. And the list is growing. Dial-up the 24-Hour Hotline (203) 853-0816 (300 baud) It's an on-line catalog, updated each day! See displays of all prod- ucts and the latest version numbers and prices. Build a trial order with- out any obligation. Complete the order only if you wish. We also offer 24-hour delivery service. Call, write, Telex or dial-up today. C.O.D., Master Card and VISA accepted. ASCOM program for time sharing and data transfers. • Transfers files between computers • Conversation mode controls remote computers • Batch mode by command files • Commands to display directories and type files ASCOM can log-on a time sharing system to retrieve stock exchange data for storage and analysis. Batch mode can make the log-on, password, data guery, and storage automatic. ASCOM can transmit program files to another micro running ASCOM — locally, or remotely through a modem. MINIMODEL™ Financial Planning' Tool — does big financial planning jobs at micro prices — for cash flow projections, financial forecasting, venture analysis, project planning and risk analysis. • Model size limited only by disk file size. •Operat- ing results can be fed into models. • Time horizon advances to elimi- nate old data • Consolidates models into higher level models • Consolidated models are process- ed u nder thei r own ru le set • Report content and format totally under user control. ■ CP/M™ programs for TRS-80 Model II, Apple with Soft- Card,™ Vector Graphic, iCom, Cromemco, North Star, Micropolis, Ohio Scientific, SuperBrain and more. GENERAL LEDGER Peachtree 7 " $550 $40 A,D,I,L ACCOUNTS RECEIVABLE Peachtree 550 40 A,D,I,L ACCOUNTS PAYABLE Peachtree 550 40 A,D,I,L INVENTORY CONTROL Peachtree 650 40 A,D,I,L PAYROLL Peachtree 550 40 A,D,I,L CLIENT WRITE-UP Peachtree 990 40 A,D,I,L PAS-3 MEDICAL Artificial Intelligence 990 40 A.CI, PAS-3 DENTAL Artificial Intelligence 990 40 A.C.I PROPERTY MANAGEMENT Peachtree 990 40 A,D,I,L PTA Asyst Design 595 40 A.C.I PTA Demo Asyst Design 75 40 A,C,I ESQ-1 Legal Micro Information 1495 50 A,C,I,L ESQ-1 Legal Demo Micro Information 75 50 A,C,I DATEBOOK'" Organic Software 295 25 A,l WOR DM ASTER™ MicroPro 145 25 A,K,L WORDSTAR'" MicroPro 450 40 A.F.K.L MAIL-MERGE'" MicroPro 125 25 A,F,K,L WORDSEARCH'" Keybits 195 40 A,F TEXTWRITER Organic Software 125 20 A M I N I MO DEL Financial Planning 495 50 A,C,I,L STATPAK NW Analytical 500 40 A.D.I MILESTONE™ Organic Software 295 25 A.I ASCOM DMA 125 10 A,T CBS DMA 395 40 A,F,K CBS LABEL OPTION DMA 80 10 A.F.K MAGSAM III MAG 145 25 A.CorD.F MAGSAM IV MAG 295 25 A,C,F,K SELECTOR IV Micro-Ap 395 25 A.CG.K PRISM/IMS MAG 495 55 A,C,F,K PRISM/ADS MAG 795 55 A,C,F,K PL/l-80'" Digital Research 500 35 B.F.L.P BASIC-80 Microsoft 350 25 A,F,L BASIC COMPILER Microsoft 395 25 A,F,L S-BASIC" Topaz 295 25 A,F NEVADA COBOL Ellis Computing 150 25 A CBASIC-2™ Compiler Systems 120 15 A PASCAL/M'" Sorcim 175 20 A,G GENERAL SUBROUTINE PAK Asyst Design 295 30 A.C.K APPLICATION UTILITIES Asyst Design 495 30 A,C,K PASCAL/MT*-™ MT Microsystems 425 30 A,G SUPERSORT I MicroPro 225 25 A,L SURVEYOR Peachtree 550 40 A,D,I,L STRING BIT'" Keybits 65 15 A STRING/80'" Keybits 95 15 A STRING/80 SOURCE Keybits 295 n/a A ULTRASORT II'" CCS 165 15 A All software has specific requirements for proper operation such as computer type, equipment configuration and support software. Check the following codes for system requirements to be certain your system will accept the software offered. (A) CP/M version 1.4 or higher. (I) Business system: 48K memory. 200K (B) CP/M version 2.0 or higher. dual disk drives, cursor addressable (C) CBASIC-2. terminal, and 132 column printer. (D) MBASIC version 4.51. (K) Cursor addressable terminal. (E) BASIC-80 version 5.0 or higher. (L) signed license required for shipment. (F) 48K memory or greater. (O) specify 8080. Z80, or CDOS. (G)56K memory or greater. (P) give CP/M serial number. (H) 64K memory. (T) serial port and modem (Z) Z80CPU. Specify disk format: North Star Single or Double, Micropolis Mod I or Mod II, 8" single density, Ohio Scientific, SuperBrain or Apple. Prices do not include shipping or C.O.D. In CT add 7%% sales tax. "Manual price will be credited against later purchase or software. Dealer inquiries invited. Copyright t 1981 Westico. Inc WESTICO The Software Express Service 25 Van Zant Street • Norwalk, Connecticut 06855 (203) 853-6880 • Telex 643-788 1. Carolina Apple Core 2. FOB 31424, Raleigh NC 27612 3. Joseph H Budge, (919) 489-4284 4. From The Core 5. Apple computer users group. 1. TRS-80 Users Group 2. 7554 Southgate Rd, Fayetteville NC 28304 3. R Gordon Lloyd 4. TRS-80 Users Group Newsletter 5. We are interested in all aspects of the TRS-80. 1. TIPS Users Group 2. 101 Brookbend Ct, Mauldin SC 29662 3. Fred Holmes, (803) 288-5664 4. TIPS Newsletter 5. Special-purpose stand- alone systems and home- brew computers. Zips 30000—40000 3. 4. Digital Publications Inc 3169 Holcomb Bridge Rd, Suite 307, Norcross GA 30071 John Rapp, Publisher, (404) 451-1156 Mini-Micro, free software exchange Software exhanges and publications for Data General, IBM, and DEC PDP-11 and PDP-8 systems. 1. Culpepper and Associates Inc 2. 4922 Heatherdale Ln, Atlanta GA 30360 3. Warren Culpepper, (404) 451-3797 4. Salt 'ri Pepper 5. Special interests: software product management. 1. CSRA Computer Club 2. POB 284, Augusta GA 30903 3. Jim Graves, President, (404) 738-1378 4. CSRA Computer Club Newsletter April 1981 © BYTE Publications Inc 165 T5€:HfiRDSID€ 6 South St .Milford, NH 03055 (603)673-5144 TOLL FREE OUT-OF-STATE 1-800-258-1790 COLOR COMPUTER $359. POCKET COMPUTER WITH INTERFACE $259. MODEL III $919. TRS-80 COMPUTERS Mod I, 64K RAM (#26-4002) $3599.00 Mod III, 16K RAM (#26-1062) $919.00 Mod III, 48K RAM (#26-1062 + ) $1039.00 Pocket Compw/lnter (#26-3501+) — $259.00 Color Comp, 4K RAM (#26-3001) . . Color Comp, I6K RAM (#26-3001+) Color Comp, Ext BASIC (#26-3002) .$359.00 .$399.00 .$529.00 MODEL I DISK DRIVES HARDSIDE 40-track Dr ( #7-40) $329.00 PERC0M TFD-40 Dr(#7-99) $379.00 PERC0M TFD-100 Dr (#7-100-1) $399.00 HARDSIDE 80-trackDr (#7-80) $449.00 PERC0M Dual TFD-100 Dr (#7-100-2) . . $799.00 PERCOM Data Sep (#7-03) $29.95 PERCOM Doubler(#?-07) $199.95 HARDSIDE Ext Cable (#7-02) $15.95 HARDSIDE 2-Dr Cable (#7-04) $29.00 HARDSIDE 4-Dr Cable (#7-05) $39.00 MODEL I PERIPHERALS COMM-80 Interf (#4-80) $159.00 CHATTERBOX Interf (#4-81) $239.00 DISK-80 Interf, 16K RAM (#4-82) .... $339.00 DISK-80 Interf, 16K RAM (#4-83). . . . $369.00 BUSY BOX Interf (#4-01) $99.95 LYNX Communications Interf (#19-80) . $229.00 RS Expan Interf 32K RAM(#26-H40-32) $399.00 16K Memory Kit TRS-keypad(#6-no2-i) $59.00 16K Memory Kit, TRS-lnterf (#5-1102) . . $59.00 Dual Joysticks for Color Comp (#26-3008)$24.95 VISTA Model II 8" Disk Dr 1 (#7-4001) . $939.00 VISTA Model II 8' ' Disk Dr 3 (#7-4002) $1795. 00 0RCHESTRA-80(#i5-03) $79.95 Upper/Lower Mod Kit (#15-02) $24.95 CPU Speed-up Mod kit (#15-04) $37.50 Video Reverse Mod kit (#15-05) $23.95 2-port TRS-BUS Ext (#15-12) $29.95 3-port TRS-BUS Ext (#15-13) $39.95 TRS-80 Model I Dust Cover Set (#16-01).. $7.95 TRS-80 Model I Carrying Case(#i7-201)$109.00 TRS-80 Monitor Carrying Case (#17-202) $84.00 CTR-80A Cass Recorder & Cable(#26-1206)$59.95 TRS-80 Model III Dust Cover (#16-05) . . . $7.95 TERMS: Prices and specifications are sub|ect to change. HARDSIDE accepts VISA & MASTERCARD. Certified checks and Money Orders; Personal checks accepted (takes 3 weeks to clear). HARDSIDE Pays all shipping charges (within the 48 states) on all PREPAID orders OVER $100.00. On all orders under $100 a $2.50 handling charge must be added. COD orders accepted (orders over $250 require 25% deposit) there Is a $5.00 handling charge. UPS Blue Label, and Air Freight available at extra cost. TRS-80 Is a trademark of Tandy Corp. 5. Users groups: TRS-80, Apple, and 6800. 1. Albany Computer Club 2. Albany Junior College, 2400 Gillionville Rd, Albany GA 31707 3. Dr Donald Cook, (912) 439-4205 5. Our interest covers all microcomputers. 1. Level II Club 2. 4406 W Lawn Ave, Tam- pa FL 33611 3. D Griffith 5. We are interested in trading original software. 1. ASCII, Sol User's Group 2. POB 10325, Tampa FL 33679 3. J Brockway, (813) 837-4655 4. ASCII 5. Sol computers. 1. CAMS (Central Alabama Microcomputer Society) 6375 Pinebrook Dr, Montgomery AL 36117 Lewis E Garrison, (205) 272-8462 READY TRS-80 hardware and software. National Association of Computer Stores 2. 3255 S US 1, Ft Pierce FL 33450 3. Steven W Koerner, Ex- ecutive Director, (305) 465-9450 4. Monthly newsletter Zips 40000—50000 1. ACSCO (Amateur Com- puter Society of Central Ohio) 2. 215 Delhi Ave, Apt J, Columbus OH 43202 3. Paul Pittenger, President, (614) 267-3412 4. I/O 5. Graphics and personal networks. 166 April 1981 © BYTE Publications Inc Circle 1 12 on inquiry card. Circle 113 on inquiry card. V The next generation of business software % v v If you've been searching for a complete line of quality software for your small business com- puter, your search is over. Designer Software is pleased to announce Phoenix'", the first line of business software to include both professional word processing and general accounting. Word Processing We designed Phoenix'" Word Processing to compete with high-priced, dedicated word pro- cessors. It is completely new from top to bot- tom and is unlike any other word processing software currently available. Phoenix'" is more powerful than WordStar 1 ", more flexible than Magic Wand™ and easier to use than either. We built "human engineering" into the product to make it easy for non-technical personnel to use. The commands are simple and logical; the documentation is well-written and organized; and the training program is something that, frankly, you'll have to see to believe. Accounting Phoenix'" Accounting includes the five general applications and a growing number of specific applications. Each accounting package was designed by CPA's and written in COBOL with an underlying assembly-language database for Designer Software HOUSTON speed. All of the general accounting packages — General Ledger, Accounts Payable and Receivable, Payroll and Inventory — have been field-tested, some for as long as two years. Specific applications include Fixed Assets Ac- counting, Mailing List Maintenance, Tenant Processing, Financial Projection, and Time/Bill- ing. We are developing more all the time. Documentation for Phoenix'" Accounting is as revolutionary as it is for Phoenix'" Word Pro- cessing. We don't just teach you which buttons to push and leave it at that. We take the time to explain the accounting principles behind the packages, because we think that you can use our products better if you understand why we ask you to do certain things. And we've made a special effort to make the manuals entertaining as well as informative so that you will want to read them. See us at the Faire We are unveiling Phoenix''" at the Sixth Annual West Coast Computer Faire. If you are planning to attend, we hope that you will drop by booth 1018-20 to see us. If you can't make it this year, write, call or contact Us via The Source and we'll send you more information. Designer Software only sells through dealers. Dealer inquiries invited. 3400 Montrose Boulevard • Suite 718 Houston. Texas 77006 (713) 520-8221 • SOURCE TCU671 Circle 113 on inquiry card. BYTE April 1981 167 MICROMAIL HAS WHAT YOUR SYSTEM NEEDS. DIABLO 630 The Diablo Model 630 is a reliable, high quality, full- character serial printer for anyone who is seeking superior print quality at a low cost. This is the first Diablo printer to offer complete interchangeability between metal and plastic print wheels. And the sophisticated and discerning user does not sacrifice print quality to obtain this versatility. Every aspect of the Diablo 630 design has been focused on maintaining outstanding print quality. Terminals also have self-test, extensive internal diagnostics and automatic bidirectional printing. $1,999.00 With Adjustable Forms Tractor add $200.00 ANADEX Standard features include expanded and com- pressed print, underlining, true lower-case descenders, RS-232C, Parallel, and 20mA inter- laces, last bi-directional printing, and high- resolution graphics. DP-9599 $1299.00 DP-9501 2K Expanded Buffer Option $70.00 TEXAS INSTRUMENTS Fast, reliable, and widely supported, the T.I. 810 has proven itseli to be a solid printer for business or industry. 810/2 $1,549.00 (includes upper /lower case option) 810/2VFC/CP $1,679.00 (includes u/1 case, forms control & compressed print) Prices good through May 15, 1981 PRINTERS C.R.T.'s ANADEX Tele Video DP9000 DP-9001 $1199 $1199 Just like the 9500/9501. but 5 inches narrower. Uses paper up to 9.5 inches wide. DIABLO 1640RO $2525 Uses plastic daisywheels, prints up to 45 c.p.s. 1650RO $2675 Uses metal daisywheels, prints up to 40 c.p.s. 912C $ 725 920C $ 795 950 $ 995 NEW! Features a detachable keyboard & programmable function keys. SOROC IQ.120 $ 689 IQ.140 $1099 IQ.135 $ 849 NEW! Microprocessor controlled, programmable function keys. C. ITOH CITIOO DEC $1625 VT-lOO $1650 TELEPRINTERS DEC LA 34 $ 969 Dot-matrix, 30 c.p.i. Adjustable character sizes & line spacing. LA34AA $1099 Includes programmable forms length control. TELETYPE 43 $ 999 Very reliable 30 c.p.s. teleprinter. Ideal for use with 300-baud acoustic couplers or modems. DIABLO 1640KSR $2830 Uses plastic daisywheels, prints up to 45 c.p.s. 1650KSR $2940 Uses metal daisywheels, prints up to 40 c.p.s. i:MJCRaMflJL., MICROMAIL • BOX 3297 • SANTA ANA, CA 92703 (714) 731-4338 To Order: Send check to MICROMAIL. P.O. Box 3297, Santa Ana. CA 92703. Personal or company checks require two weeks to clear Visa/MasterCard accepted. C O.D. requires a 15% deposit. Handling: Add 3% to orders less than 3750, 2% to orders $751 ■ S2.000. 1% to orders over $2,000 NOTE: Handling charges are waived on orders pre-paid in advance by check Shipping: We ship FREIGHT COLLECT via UPS or Motor Freight Air and Express delivery is available. 1. Midwest Affiliation of Computer Clubs 2. POB 20205, Columbus OH 43220 3. Douglas Troughton, (614) 574-8152 4. MACC-Pack, and Cotn- puterfest 5. Promoting personal com- puting by helping mem- ber clubs in any way possible. 1. TI 99/4 Users of Cincin- nati 2. 8075 Spring Garden Ct, West Chester OH 45069 3. Larry Morrow, (513) 777-7042 5. Exchange of information and ideas concerning the TI 99/4. 1. DMA (Dayton Micro- computer Association) 2. c/o Dayton Museum of Natural History, 2629 Ridge Ave, Dayton OH 45414 3. Gary Turner, (513) 848-6911 4. Data Buss 5. Numerous special interest groups and help for beginners. 1. Apple-Dayton Users Group 2. 4819 Leafburrow Dr, Dayton OH 45424 3. Dick Peschke, Secretary, Gone with the wind. We could lose our national symbol . . . the majestic bald eagle. Once man drives eagles out of their nesting areas, they rarely return. Today there are only about 900 pairs of eagles known to be nesting in the lower 48 states. We can save the eagle by establishing eagle preserves. You can help. Join the National Wildlife Federation, Department 102, 1412 16th Street, NW, .Washington, DC 20036. Let's keep the eagle £5^3 around another hundred years. 168 April 1981 © BYTE Publications Ire Circle 114 on inquiry card. Circle 115 on inquiry card. £ ■- / A y > //// osy ,.;. /•■; ?t '!:':•: I : i : llll .-. : --v' L - . //'ii / SAVE $50 We design and manufacture a complete line of industry compatible microcomputer assembled and tested boards and kits for your system. All are S-100 bus compatible and use the Z-80 microprocessor. With over 25,000 boards and hundreds of computer sys- tems installed throughout the world, SD Systems offers you both proven and state-of-the-art products! We pro- vide you with a complete family of kits for all your sys- tems needs — SBC 100/200 — A 2.5/4 megahertz range of single board computers which are effective standing alone or combined with the complete SD board range. ExpandoRAM till — For use with 250/200 nanosecond \ RAM, these high density boards offer 16 to 64K memory; \ the ExpandoRAM II can achieve RAM capacities up to ' 256K using 64K chips. ' Versafloppy //// — A floppy disk controller for up to four drives, supporting single/double density and single/dou- ble-sided disk formats. VDB-8024 — A full function visual display board with a Z-80 controller that adds display capabilities to your system. Z-80 Starter Kit — A low-cost entry into the world of microcomputers designed primarily for education and experimentation. Prom 100 A specialty board of SD Systems which allows you to program 2708/2716/2732 proms. SD SYSTEMS P.O. Box 28810 • Dallas, Fexas 75228 • Telex 6829016 y <*\ ':■■■ ■-' " N V V YOU CAN SAVE $50 when you purchase any two SD Systems board kits from participating DEALERS and present coupons included in any two kits to participating DEALERS listed below. Coupons must be presented to participating DEALERS by 10-15-81. A.S.A.P. COMPUTER PRODUCTS SlqnalHill, Ca. 213-595-6431 Q. T. COMPUTER SYSTEMS, INC. I awndale, Ca, 213-970-0952 f COMPUTERS, ETC i Dallas, Texas 214-644-5030 v JADE COMPUTER PRODUCTS Hawthorne, Ca. 800-421-5500 COMPUTER CENTRE Swansea, England, U.K. 44-792-460023 ARCON ELECTRONICS LTD Toronto, Ontario, Canada 416-868-1315 RATIONAL SYSTEMS Buckinghamshire, U.K. 0908-61 1349 ALPHA BYTE STORES Calabasas, Ca. 213-883-8594 ARISIA MICRO SYSTEMS Mississauga, Ontario Canada 416-274-6033 SIRTON PRODUCTS Surrey, England, U.K. UK-OI-660-5617 V.\» GIFTS FROM PROMETHEUS NEW for APPLE II Advanced products at Down-to-Earth PRICES DUAL SERIAL CARD-1. All functions of two independent serial cards on one board -plus more. Provides Apple ll (1) users with two simultaneous asynchro- nous serial channels. DSC-1 appears as two separate logical serial cards to the Apple ll (1) . Fully software compatible with all Apple ll's (1) and Microsoft software. 2716 EPROM used for easy driver modification. In addition, the second serial channel supports these extra features: • Strapable DCE/DTE. • Secondary RS-232 handshake functions (DCD, DTR, DSR) • Strapable logical slot location and hardware looks like it's another slot. Order: PP-DSC-1 @ $189.00 each DUAL SERIAL/PARALLEL CARD-1. As with the Dual Serial Card-1 (above), the Dual Serial/Parallel-1 provides Apple users with simultaneous use of one full serial port and one parallel port. Both ports strapable for any Apple peripheral slot. Fully compatible with all Apple and Softcard (CP/M) software. Drivers for serial interface and Centronics parallel interface are contained in modifiable industry standard EPROM. Serial port is configured like DSC-1 . Order: PP-DSP-1 @ $189.00 each. MEMORY EXPANSION MODULE-1. Expand your Apple ll< 1 >to afull64K RAM system with highest quality 1 6K dynamic RAMS. Fully buffered to provide reliable operation - even with fully loaded Apples. Total compati- bility with Microsoft Softcard (2) /CP/M (3) and all Apple software. Supplied complete with installation instructions and test program. Order: PP-MEM-1 @ $149.50 each. PASCAL MT+ MEM-1. A modular native Z-80 code Pascal compiler. ISO standard. Includes a MEM-1 (detailed above). Have a full Pascal compiler at half the Apple price. Requires a Microsoft Softcard <2) and two disk drives. Note that the Pascal MT+ alone is normally $250.00. Order: PP-PMT-1 @ $299.00 each. 16K RAM ADD-ON rOTS. For TRS-80 and Apple ll (1) . Eight (8) full- specification industry standard 1 6K RAMS. These are not seconds. Order: PP-RAK-16 @ $29.00 each. All Prometheus boards are completely tested and burned-in prior to shipment. One-year warranty covers parts and labor. MONEY BACK GUARANTEE: Order now without risk. Boards may be returned, in good condition, after up to 10 days df trial for a full and prompt cash refund. California: add 6% tax; BART Counties, 6 1 /2%. Orders under $150, add $3.00 postage, for handling charge. Freight allowed on orders over $150. Dealer inquiries invited. Quantity discounts available. PROMETHEUS PROMETHEUS PRODUCTS INCORPORATED 4509 Thompson Ct. • Fremont, CA 94538 • (415)791-0266 Registered Trade Marks: (1) Apple Computers, Inc. (2) Microsoft Consumer Products (3) Digital Research. Inc. VfSA i 7*t (513) 236-3619 Apple-Dayton Newsletter 1. 2. TRI-STATE Computer Club 2669 Highmeadow Ct, RT 1, Wheelersburg OH 45694 Douglas Troughton, (614) 574-8152 Yes Special interests: TRS-80, Apple, OSI, KIM, PDP-11, and 6800 systems. AIM-65 User's Group R R#2, Spencerville OH 45887 Donald Clem, (419) 647-6576 Target Special interests: AIM-65- and 6502-related informa- tion. 1. Apple One Library 2. 51625 Chestnut Rd, Granger IN 46530 3. Joe Torzewski, (219) 272-4670 5. We actively support the Apple I computer. 1. 1. Northern Indiana Com- puter Hobbyist Exchange 927 S 26th St, South Bend IN 46615 Eric Bean, (219) 288-2101 NICHE Newsletter Evansville Computer Club 2. c/o National Sharedata Corporation, POB 3895, Evansville IN 47737 3. Robert Heerdink 5. Special interests: S-100, TRS-80, Bally, and Apple systems. 1. The Midwest Buss 2. 441 E Bemhard, Hazel Park MI 48030 3. Art Blundell, (313) 547-3011 5. Special interests: our buy-and-sell forum and swapping news from club to club. 1. Sorcerer's Apprentice Computer User's Group 170 April 1981 © BYTE Publications Inc Circle 116 on inquiry card. If you are the owner of an Apple, Pel, Atari, orTRS-80 ami also have a disk drive, we have some of the those systems u/ith sound capability, our games have Crystalsonics — a newly developed concept in tone generation. For Apple and Atari (here are some truely superlative hires graphics. In fact, Sands of Mars offers 3-D graphics and flight simulation landing. It includes over 186 full screen hires maps of Martian terrain. ••***••**** We now serve over 30 countries around the world. Dealership and distrihutor inquiries are welcome. Special rates are available on larger orders. We have 48 hours delivery to anywhere in the continental United States. We are also looking for experienced programmers and new game software. Our royalty terms are extremely generous. If you have what you consider to be a quality product that you would like to have marketed please give us a call. If you would like to be a member of the Crystal User's Club and be eligible to receive free user contributed software, please submit a program of any type and a $10.00 membership fee. In return you will receive a Crystal Membership Card, a copy of The House of Usher, and a year's subscription to Crystal Vision. HOUSE OF USHER — Wander through a haunted house. Rooms and scenery in 15 color lo-res graphics. We offer a $100.00 prize to the first person to solve the mystery. Over 200 monsters, objects and perils. $24.95 GALACTIC QUEST — Crystalsonics - hires graphics -the ultimate space adventure. Vegan warships attack and fire in real time simula- tion. Land on and trade with over 64 star systems in 3 galaxies. Allow 6-12 hours for play. $29.95 SUMER — Travel back through time to ancient Sumeria in the middle cast. You are given 10 years as king to restore this kingdom to prosper- ity. Plant, war, consult the astrologers - very hard to beat! $19.95 LASAR WARS — Crystalsonics - hires graphics - protect the planet earth from a full scale alien invasion. Over three types ol invading craft and hundreds of approach simulations. The games speaks for itself. $29.95 WORLD WAR III — Crystalsonics - hires graphics - for you war game freaks, this is it! Iran and Irag - nuclear missiles - hires 3 scene bat- tlefield - demolition squads - tanks - strategy. Custom designed for two arm chair generals. Save the world from nuclear holocaust! $29.95 BENEATH THE PYRAMID - Crystalsonics - hires graphics - brand new! Explore the pyramids and miles of winding secret tunnels beneath I hem. Enter at the Sphinx and find the hidden treasure chamber . All in hires with very aggressive monsters and many many perils. To win you must find the golden cat and your way out!!! $29.95 LITTLE CRYSTAL — Especially designed anthology for children from ages 5 to 80. Includes Mr. Music which turns your Apple into an organ ul sorts, gunk where two weird monsters shoot it out and many other educational as well as entertaining programs for children. True unique addition for kids who always feel left out of Dad or Mom's computerizing. $39.95 SANDS OF MARS — What we at Crystal believe to be the fittest advettlure game available to dale. In addition to hires graphics and super tone routines where the user's system will support it, this game provides landing simulation, animation, and revolutionary 3-D graphics. It is the ultimate in space adventure and may takeseveral weeks or months to play. It istheOydessy of the Slarship Herman on its maiden flight to Mars. Hie initial lilt- off is animated and paddle controlled. The flight through space is in Hires 3-D Graphics with many animated scenarias. You must land your slarship on Mars, it will lack enough fuel and supplies for a return voyage. You must lead your party through hundreds of Hires maps of Martian let rain and subterrainian passages. You then will secure adequate resources for take off, navigate your ship back to earth and attempt a successful touchdown. There is a mystery buried in the ancient city of Lemuria beneath the sands of Mars. We offer a $100.00 prize to the first space gamer to discover it. Good luck! $39.95 For more information you may write or call: Crystal Computer, 12215 Murphy Avenue, San Martin, California 95046 (408) 683-0696 atMicrohouse Spring Qeanirig Sweep up savings on leading hardware and software! We at Microhouse would like to thank you worldwide for your tremendous response to our wide range of discounted hard- ware and software. To serve you better, call or write us any- time for your hardware and soft- ware needs. If you don't see it, ask! We will attempt to meet or beat any advertised price! Software Manual List & Manual/Only Software D WORDSTAR The premier word pro- cessing, software from MicroPro S49S.00 $322/840 :_■ MA1LMER0E option for Wordstar 2 X S150.00 $110/825 D WORDMASTER by MicroPro. S150.00 $118/825 D SUPERSORT I by MicroPro. Can be used as a stand-aJone program or can be linked to programs with a Microsoft format $250.00 $189/825 O SUPERSORT II A stand alone-only ver- sion of above. ...$200.00 $18S/$25 D DATASTAR by MicroPro. $350.00 $289/535 O SPELLGUARD checks 20 pages of copy for spelling mistakes and typos In less than a minute. Can be used with many CP/M® word processors (inclu- ding WordStar). Lets operator review words It judges as potential errors. Oper- ator may then change the suspect word or add if to SPELLGUARDs 20.000 word dictionary (dictionary size limited onty by disk space). $295 $230/$20 D dBASE II, the assembly-language re lalional Database Management System for CP/M* . No need for host language Handles up to 65.000 records (up to 32 fields of 1 K each). English-like com- mands. Report generator with user-de- finable fun-screen operation. Win read existing ASCII files ..$700 S628/J20 D TCS/AManta INTERACTIVE AC- COUNTING SYSTEM for small busin- esses New release. Each package can be used atone or post automatic- ally to the General Ledger. Available in complied version (no support lan- guage needed) or in source (MBASIC required). Needs 48K RAM. 132-col. printer. 24x80 CRT and CP/M* COMPARE AT UP TO J530/pkg. GENERAL LEDGER $757125 ACCOUNTS RECEIVABLE . . $757$25 ACCOUNTS PAYABLE $75/825 ACCOUNTS PAYABLE $75/825 PAYROLL $7S/$25 ALL FOUR »259/$25 SAMPLE PRINTOUT BOOK of ALL FOUR $15 D STRUCTURED SYSTEMS ACCOUN- TING SYSTEM (Requires CBASIC2. 2 dsk drives, 24xS0 CRT. 132-cokjmn width printer). . . LIST: $1250.00 each GENERAL LEDGER $899/840; ACCOUNTS RECEIVABLE . . $689/840 ACCOUNTS PAYABLE $6>0/$40 PAYROLL $698/840 INVENTORY $337/$40 □ BASIC 80 by Micro. Version 5.2 and 4.51 Included. . . . $350.00 $299/130 D BASIC COMPILER by Microsoft. Lan- guage compatible with MBASIC. In- cludes MACRO 80 assembler $395.00 $33 'i ^iaflh TRANSISTOR SPECIALS 2N1307PNPGETO5 2N404APNPG£T0 5 HEPG6Q14 -PNPGETC3 TIP121 - NP\S SW.TCHING 2N6233-NPN SW Ti MING POWER. MRF-BOOtaCi'lii l-.'.NSis'nflNPN. .. $ . 2N3772NPNS TO-3. ... . $1. 2N4908PNPR TO 3. $1. 2N50B6PNPS H)92 4/$1, 2N3137NPNSi=1r- . . . $ . 2N3319 NPN S. TO 3 PF .. $1, 2N1420NPN ~ 74150- 1.10 74363 - 7442- .50 74151 - .6b 7445- /() 7446 - ,75 75154- 1.10 7447 - .75 74155 - .7b 7448 - ,75 74157 - .lib 8T98 - FULL WAVE BRIDGE PRV 2A 6A 25A 100 1.40 200 .80 1.30 2.20 400 1.00 1.6S 3.30 600 1.30 1.90 4.40 DIP SOCKETS SPIN .17 22PIN .30 14 PIN ,20 24 PIN .3b 16PIN .22 28PIN .40 18PIN .25 40PIN .60 74LS SERIES 74LS01 - 74LS02 - 74LS03 - 74LS04 - 74LS05 - 74LS08 - 74LSD9 - 74L5I0 - 74LS11 - 74LS12 - 74LS13 - 74LS14 - 74LSI5 - 74LS2D - 74LSZ1 - 74L522 - 74LS26 - 74LS27 - 74 L 528 - 74LS3Q - 74LS32 - 74LS37 - 74LS74 - 74LS75 - 74LS76 - 74LSB3 - 74LS85 - 74LS96 - 74LS107 ■- 74LSI09 - 74LS112- 74LS113 - 74LE114 74LS123 - 74LS125 - 74LS126 - 74LS132 - 74LSI36 - 74LS138 - 74LS139- 74LS151 - 1.19 74LS153-1.19 74LS1 55-1.19 LINEAR CIRCUITS 136- .! 900 - .! M307 - M30a - M324 - LM348 - .90 LM358 - ,70 LM361 - 1.7! LM377 - LM382 - LM336 - LM3B7 LM553 LM555 - .45 LM553 ,60 - 2.25 566 - 1.25 CA758 - CA3018 - CA3046 - CA3078 - CA3080 - CA30B6 - CA3094 - NE540L - REGULATORS 74LS157 74LS160- 1.00 74LS1B1 - 74LS163- LOO 74LS16.1- 1.00 74LS16B ■ 1.25 74L5169- .75 74LS170- 74LS173- .90 74LS174- 1.00 74LS175- ;.00 74L5181 - 2.50 a 74LS191- 74 LSI 92 - .90 74LS193 74LS194 - 1.10 74LS195- .90 74 LSI 96 1.00 74LS197- .90 7JLS241 1.60 74LS242 - 1.60 ;.'.i S2'ji 1.28 1.00 74LS258- .90 74LS259 - 74LS273- 74LS283 - .80 74LS290 - 71LS293 .80 74LS365- 74LS3G7 - 74LS373- 74LS38r, - .50 74LS393 - 1.50 LM1B10 - 2.20 Ml 88 LM317T... LM337 323K-bV3A. 73HGKC-5V; ..,.$2.50 ... $2.50 . . . .$5.75 5A $6.95 LM305G $ 340K-12, 15or24V S 340T-5, 6, 8, 12, 15 POSTAGE ADD 10% FOR ORDERS UNDER $20.00 RATES ADD 5% FOR ORDERS BETWEEN $20.00 AND $50.00 ADD 3% FOR ORDERS ABOVE $50.00 TERMS: FOB CAMBRIDGE, MASS. SEND CHECK OR MONEY ORDER. MINIMUM TELEPHONE. C.O.D. PURCHASE ORDER OR CHARGE $20.00 MINIMUM MAIL ORDER $5.00. SEND 5.25 FOR OUR CATALOG FEATURING TRANSISTORS & RECTIFIERS. 145 HAMPSHIRE ST., CAMBRIDGE, MASS. 02139 SOLID STATE SALES P.O. BOX74B SOMERVILLE, MASS. 02143 TEL. (617)547-7053 WE SHIP OVER 95% OF OUR ORDERS WITHIN 24 HOURS OF RECEIPT TOLL FREE 1-800-343-5230 1. H8SCOOP 2. 2918 S 7th St, Sheboygan WI 53081 3. Henry E Fale, (414) 452-4172 5. Special interests: Heathkit H-8 and H-89 computers. 1. Fox Valley Crab- Apples 2. Mathematics Department, University of Wiscon- sin — Oshkosh, Oshkosh WI 54901 3. John Oman, (414) 424-1362 5. Use of the Apple II in the classroom. 1. MICRO 2. 335 W Prospect St, Appleton WI 54911 3. John Ensley, (414) 731-7183 4. Yes 5. Special interests: com- puter networks, graphics, and educational uses. 1. Mini 'Apples 2. 13516 Grand Ave S, Burnsville MN 55337 3. D Buchler, President, (612) 890-5051 4. Mini 'Apples Newsletter 5. Apple II users group. Special interests: Pascal, education, personal, business, and industrial applications. 1. XXX-11 2. POB 2017, Fargo ND 58107 3. C R Corner, (218) 233-7894 4. XXX-11 Newsletter 5. Special interests: languages. Zips 60000—70000 1. Dental Computer Newsletter 2. 1000 North Ave, Waukegan IL 60085 3. E Neiburger, Editor, (312) 244-0292 4. Monthly 5. Special interests: 172 April 1981 © BYTE Publications lnc Circle 118 on inquiry card. 2716 (5V) $8.95 4116 200NS $3.50 2114L 300NS $3.75 NEW! IT TALKS "FAST TALKERS S-100" LOW DATA RATE S100 SPEECH BOARD • UNLIMITED SPEECH POSSIBILITIES • S100 INTERFACE • USES TEXAS INSTRUMENT TMS 5200 V.S.P • SOFTWARE. VOICE DATA ASSEMBLER • 32 WORD VOCABULARY INCLUDED • AUDIO AMP W/SPEAKER • ASSEMBLED AND TESTED NEW TECHNOLOGY SPEECH PROCESSOR ALLOWING UNLIMITED SPEECH POSSIBILITIES DELIVERY FROM STOCK TMS-5200 VOICE SYNTHESIS PROCESSOR Chip with Data Sheet $69.00 $329. "CONTROL TALKER II" 110V 50/60 HZ 32 INPUT LINES (TTL) 32 10 AMP (50V) OUTPUT LINES Z80 BASED SYSTEM 8K PROM (SOCKET) 1K RAM VOICE OUTPUT SINGLE BOARD STEPPING MOTOR CONTROL (UP TO 8) Control Talker II can be used to control stepping motors, relays, counters, etc., and support a variety of uses including robotics, telephone dialer, digital access, security, aulo drilling, measuring, counting and virtually unlimited applications with added speech output to advise of status etc. Put one to work for you today! $550. Double Sided QUME DRIVES DATATRAK 8 ° R U , R CE $540.00 (Regularly) $808.00) CALIFORNIA COMPUTER SYSTEMS Order Number 2032A 32K Sialic 20338 32K Sialic 2032C 32K Sta EM450NS EM-300NS EM-2C0NS I MEM-200NS 2065C 6a K Dy 2116A igk Static MEM-450NS 2M6B 16K Slahc MEM300NS 21I6C 16K Sialic W6M-20ONS 2116X 16K BD oniy 22C0A Mainframe 110.60 2422A Floppy Controller 2710A 4-Porr Serial I/O 271BA SciauParaiiei I/O 2720A 4-Port Parallel HO 2810A 2 80 CPU BD APPLE BDS: 1 560 00 640 00 649 00 569.00 257 00 26100 290 00 67 00 386 00 320 00 279,00 290 00 200.00 235 00 7470A AID Converter 7490A GP1B IEEE 4KB 77 IDA Serial Asyncrt 9( 77I2A Serial Syncn Ba 7720A S 63 00 103 00 90 00 97 00 230 00 127 00 152 00 99 00 I 99 00 329 00 79L VOLTAGE REGULATORS art" Case Price ,i 05 J 092 45 IL12 I"092 45 ItS T092 45 T092 65 TQ92 65 T092 65 TO220 1 20 TO220 1 20 TO220 1 20 TO220 1 25 TO220 1 25 TO220 1 25 79U5 7805 P 7B12P 78I5P 7905 P 7912P 7915P 7805K 7812K 78I5K 7905K 7912K 7915K 309M 309K 317P 317K 323K 337P 337K 350K I03 T03 T039 T03 T022U T03 T03 TO220 T03 T03 CRYSTALS (Parte Includes Iraquoncy In MHZ) Parl# SYi SYI 8432 SV2 SY2.4576 SY3.579 SY4 SY5 068 SY6 SY6 144 SYS Price 575 5.75 5.75 5.75 5.75 4.50 450 CERAMIC DISC CAPACITORS 50V Value 1 + 25+100 + 4 7pf 07 06 04 lOpI 07 06 04 22pf 07 06 04 33pf 0/ 06 04 39pl 07 06 .04 47p( 07 06 04 68pl 07 06 .04 100pl 07 .06 .04 150pf 07 06 04 220pl 07 06 .04 270pl 07 06 04 330pt 07 06 .04 ,0022ml 0033ml 0047ml DIODES Switching IN914 12*1 00 1N414S 12S100 LOW-PROFILE SOLDER TIN PartW 1 + 25+100 + S8LT 15 n 08 SI4LT 18 16 14 S16LT 2t 18 16 S18LT 26 22 18 S20LT 31 26 20 S22LT 33 28 22 S24LT 35 29 24 S28LT 41 34 26 S40LT 53 4 7 40 WIRE-WRAP SOLDER TIN Part* 1 + 25+100 + SBWT 37 33 30 S14WT 48 43 39 S16WT 53 -18 -»3 S18WT 61 55 50 S20WT 65 77 69 S22WT 69 80 72 S24WT 96 86 77 S28WT 1.22 111 99 B40WT l 75 '57 1 40 WIRE-WRAP GOLD Pari* S8WG S14WO SI6WG S18WG S20WG S22WG S24WG S28WG J.".J0vVG SOLID DIPPED TANTALUM CAPACITORS 20% ValuB Volls 1 + 25+100 + 2 2ml 3 3ml 4 7m) T.55 1 29 1 05 V* WT & 5 VaWT CARBON I % RESISTORS 2.2K 2.4K 2.7K 3K 3.3K 3.6K 3.9K 5.1K 5.6< 6.2< 6.8 < 2O0K 220K 240K 270K 300K 330K 360K 390K 430K 470K 5I0K 560K 620K 680K 750K 820K 2.2M 2.4M 2 7M 3M 3.3M 3.6M 3.9M MINIMUM ORDER PER TYPE: 5 pes— any qty 5 pack @ $.25 MINIMUM ORDER PER TYPE: 100 pes Price Per 100 Pk: QTY 'AWT '/.WT 100 up 51.70 $1.80 1,000 up 1.50 1.60 5.000 up 1.30 1.40 10.000 up 1 10 1.20 ZENER DIODES Vi WT Part# Price 1N5231B 1N5239B 1N5242B 1N5245B 1N5248B 1N5250B 1N5252B IN5255B 1 WT 1N4733A 1N4739A 1N4742A 1N4744A 1N4746A IN4747A 1N4749A POLYESTER CAPACITORS + & - 10% TOLERANCE 50V Valui OOtrn' 0012ml 0015ml OOlBmf 0022ml 0027 ml 0033ml ,0039ml 0047ml 0056ml 0068ml .0082fnl .01ml 012ml 015ml 018ml .022ml ,027ml ,033ml ,039ml 047ml .056ml 068ml 0B2ml .27ml .33ml 39ml 47ml H 100 + TRANSISTORS 2N2219A S .35 2N2222A .25 2N2905A ,30 2N2907A .25 2N2369A 25 2N3904 20 2N3906 20 PN2222A 19 PN2907A 19 RECTIFIERS (1A) 1N4001 1N40O2 IN 4003 1N4004 12100 12100 1 2/1 .00 121.00 1N40O5 10/1.00 08 IN40O6 11/1.00 08 1N4007 10(1.00 08 74 LS Part U Price 74LS00 32 74LS01 32 74LS02 32 74LS03 32 74LS04 32 74LS05 32 74LS08 .32 74LS09 .35 74LSIO .3B 74LS11 38 74LSI2 39 74LS13 32 74LS14 65 74LS15 35 74LS20 32 74LS21 36 74LS22 36 74LS26 35 74LS27 39 74LS28 37 74LS30 36 74LS32 40 74LS37 36 74LS3B 36 74LS40 36 74LS42 95 74LS47 1 15 74LS48 1 15 74LS51 .32 74LS54 .38 74LS55 .34 74LS73 49 74LS74 49 74LS75 63 74LS76 55 74LS83 95 74LS85 125 74LS86 .55 74LS90 79 74LS92 75 74LS93 75 74LS95 .99 74LS107 50 74LS109 .50 74LS112 52 74LSU3 52 74LS114 .52 74LS123 1.05 74LS125 70 74LS126 .70 74LS132 .95 74LS136 53 74LS13B 85 74LS139 .85 74LS148 1.75 74LS151 79 74LS152 79 74LS153 79 74LS154 2 05 74LS157 1 15 74LS15B 1 15 74LS160 85 74LS161 85 74LS162 .85 74 LS 163 95 74LS164 1 10 74LS165 1 10 74LS166 255 74LS170 1.90 74LS173 135 74LS174 l 25 74LS175 95 74LS1B1 235 74LS190 I 15 74LS191 1.15 74LSI92 1.15 74LS193 1 15 74LS194 1 15 74LS195 1 15 74LS196 99 74LS197 99 74LS221 .95 74LS240 1 05 74LS241 1 05 74LS242 1.45 74LS243 1.45 74LS244 1 05 74LS245 2 15 74LS251 129 74LS253 .99 74LS255 99 74LS257 1 15 74LS25B 1.15 74LS260 .95 74LS261 249 74LS266 65 74LS273 165 74LS283 1.05 74LS365 .85 74LS366 85 74LS367 85 74LS368 85 74LS373 1 65 74LS374 1 45 74LS375 99 74LS377 1.15 74LS3B6 59 74LS390 I 75 74LS393 1 75 81LS95 1.35 81LS96 135 81LS97 135 81LS9B 135 4000 CMOS Part -i Price 4000 4001 4002 4006 4007 4008 4009 4016 4017 4018 4019 4020 4025 4026 4027 4028 4029 4030 4034 4035 4040 4043 4044 4046 4047 4052 4053 4060 4066 4072 4073 4075 4076 4077 4078 4081 4082 4093 4503 4508 4510 SERIAL PORT CARD WITH 4 PORTS $289 WITH 2 PORTS $260 MIN ORDER: $10.00 SHIPPING: ADD $2.00 GA RESIDENTS ADD 3% SALES TAX MASTERCARD AND VISA WELCOME MAILORDERSSOUTHERN SEMICONDUCTORS INC. BOX 986 LAWRENCEVILLE, GA. 30246 PHONE ORDERS: OEM AND INSTITUTIONAL INQUIRIES INVITED (404) 963-3699 Circle 120 on inquiry card. BYTE April 1981 175 ENTREPRENEURS Imli 1 ™!™! W m U I MORE THAN EVER IN THE MICRO- IVkkl#hll# COMPUTER INDUSTRY. The shortage of knowledgeable dealers/distributors is the «1 problem of microcomputer manufacturers Over 300 new systems houses will go into business this year but the number falls short of the 1200 needed It is estimated thai the nal "in wide shortage of consultants will be over 3000 by 1981 The HOW TO manuals by Essex Publishing are /out best guide lo start participating in the continued microcomputer boom (36 HOW TO START YOUR OWN SYSTEMS HOUSE 6th edition March 1980 Written by the lounder of a successful systems house, this tai Milled 220-page manual covers virtually all aspects of starting and operating a small systems company It is abundant with useful, real-lite samples contracts proposals, agreements and a complete business plan are included in lull, and may be used immediately by the reader Proven, field-tested solutions lo the many problems lacing the small systems house are presented From the contents: • New Generation of Systems Houses • The SBC Marketplace • Marketing Strategies • Vertical Markets & lAPs • Competitive Position/ Plans ot Major Vendors • Market egment Selection & Evaluation • Selection ol Equipment & Manufacturer • Make or Buy Decision • Becoming a Distributor • Getting Your Advertising Dollars Worth • Your Salesmen Where to Find Them • Product Pricing • The Selling Cycle • Handling the 12 Most Frequent Objections Raised by Prospects • Financing foi the Custom©! • I easing • Questions You Will Have to Answer Before the Prospect Buys • Producing the System • Installation, Acceptance, Collection • Documentation • Solutions to the Service Problem • Protecting Your Product • Should You Start Now'' • How to Write a Good Business Plan • Raising Capital HOW TO BECOME A SUCCESSFUL COMPUTER CONSULTANT HOW TO BECOME A SUCCESSFUL COMPUTER CONSULTANT by Leslie Nelson, 2nd revised edition Jan 1981 Independent consultants are becoming a vitally important factor in the microcomputer field filling the gap between the computer vendors and commercial/industrial users The rewards ol the consultant can be high treedom, more satisfying work and doubled or tripled income HOW TO BECOME A SUCCESSFUL COMPUTER CONSULTANT provides comprehensive back- ground information and step-by-step directions for those interested to explore this lucrative field • Established consulting markets* How to get started • Itemized start-up costs • Are you qualified 7 • Beginning on a part time basis • The Marketing Kit • Should you advertise? • Five marketing tips • Getting free publicity • How much to charge • When do you need a contract 9 • Sample proposals • Which |Obs should be declined • Future markets • The way to real big money • Avoiding the legal pitfalls • How consultants' associations can help you • The National Register of Computer Consultants • How others did it real-life sample cases «and much more. ESSEX PUBLISHING $28. No, 16 FREE-LANCE SOFTWARE MARKETING 3rd edition. June 1980 Writing and selling computer programs as an independent is a business where • you can get started quickly, with little capital investment • you can do it full time or part time • the potential profits are almost limitless Since the demand lor computer software ol all kinds is growing al an explosive rate, the conditions lor the small entrepreneur are outstanding This manual will show you how to sell your own computer programs using these proven techniques • direct to industries • through consulting firms • through manufacturers of computer hardware • in book form • mail order • through computer stores It will show you how to profitably sell and license all types of software ranging from sophisticated analytical programs selling lor thou- sands of dollars, down to simple accounting routinesand games for personal computers The book will guide you step by step through the process ol S30. No. 32 marketing, advertising, negotiating a contract, installing software, training users and providing maintenance and support It also contains sample software contracts that have been used in actual software transactions Also included are tips on how to negotiate with a large corporation ways of avoiding personal liability techniques for obtaining free computer time and hints on how to run a free-lance software business while holding a full-time job ESSEX PUBLISHING CO. Dept «■ ;J«.'j nioomlield Avenue • Caldwell, N.J 07006 I- ■ I " lei books by numt lend hei I m • • . • lei i ■ r Ma ite e ». Publ rier pa i riipping ForUPS di| ping IA only) addSLOOpei I idd ! pei book in II i 1 1 ' ' i nd Central America , I i N .... iiesta DNo 10 ONo 16 ONo32 □ Che iss OUPS OAir Name A Ho State Card H r F or taster shipment on credit card orders call (201 1 783-6940 between 9 and 5 Eastern lime . Exp Zip 5. We have an ABBS (Apple Bulletin Board System) on (402) 423-8086. Compusers POB 2064, Hastings NE 68901 Rocky Friend, President; or Dorothy Friend Secretary (..orrijiusers We have a number of different makes ot micro- computers and are in- terested in all subjects concerning computer use. 3. Zips 70000—80000 1 99 4 Home Computer Users Group ' POB 95148, Oklahoma City OK 73143 .'.. Charles LaFara, (405) 787-8521 4. Monthly newsletter 5. We have a program ex- change and are looking fi 'i more information on TI BASIC. 1. The Tulsa Computer Society 2, POB 1133, Tulsa OK 74101 3. Mike Parr, (918) 492-8292 ■i I i I Port 5. Everything! Theatre Computer Users Group 104 N St Mary, Dallas TX 75214 Mike Firth, (214) 827-7734 TCUG Notes Spec ial interests: the use of computers in live drama. 1. FWAUG (Fort Worth Apple Users Group) 2. 1401 Hillcrest Dr. Arling- ton TX 76010 3. Lee Meador, (817) 461-1981 4. FWAUG Newslettri 5. Apple hardware and soft- ware. 176 April 1981 = BYTE Publication* btc Circle 121 on inquiry card. GgGgGgGgGgGgGgGgGg GgGgGgGgGgGgGgGgGg GgGgGgGgGgGgGgGgGg GgGgGgGgGgGgGgGgGg HhHhHhHhHhHhHhHhHhl HhHhHhHhHhHhHhHhHhH HhHhHhHhHhHhHhHhHhHl HhHhHhHhHhHhHhHhHhHh IgGgGgGgGgGgGgGgGgGgGgGg g GgGgGgGgGgGgGgGgGgGgGg ^GgGgGgGgGgGgGgGgGgGgGg GgGgGgGgGgGgGgGgGgGgGg ihHhHhHhHhHhHhHhHhHhHh . iHhHh'HhHhHhHhHhHhHhHh ^HhHhHhHhHhHhHhHhHhHh m 'HhHhHhHhHhHhHhHhHh APPLE H Computer - now with genuine upper/lower case We used to think the sophistication of the Apple 11/ PLUS could not be improved upon. With increasing availability of business software capital letters on the screen are not sufficient. Especially for wordprocessing and the PASCAL editor the lack of lower case was disturbing. After searching for a better solution we developed a new keyboard-encoder to implement upper and lower case in the keyboard and on the screen. • typewriter mode or ALPHA-LOCK mode operation • all keys with AUTOREPEAT • four character sets including FULL ASC II, and EUROPEAN sets • no soldering, no wiring • simply replace the plug-in encoder-board Fix your system today, so tomorrow you're not stuck with just capital letters. Ask your Apple dealer for the new keyboard-encoder from BASIS. For S 125,00 you save time and get a new clear screen. INCORPORATED Apple II is the registered trademark of apple computer, inc. BASIS, Inc., P. O. Box 2029, Los Gatos, CA 95030 Clubs and Newsletters, 1. Club 1802 2. POB 985, Dickinson TX 77539 3. John L Hubisz, (713) 938-4098 4. Newsletter 5. Our activities are for beginners in microcom- puting. We use ELFs and other 1802-based boards that employ simple con- trols, 1 . High Plains TRS-80 Users Group 2. POB 30545, Amarillo TX 79120 3. Tom Whittenburg, (806) 374-971 J 1. Permian Basin Amateur Computer Group 2. c/o Ector School District, POB 3912, Odessa TX 79760 3. John Rabenaldt, (915) 697-4607 (after 6 PM) or (915) 332-9151 (9 AM to 5 PM) 5. Special interests: Selectric interlaces, color displays, MECA tape, and Altair 8800 systems. Zips 80000—90000 1. 2. 3. 5. Apple it 415 E 43rd, Odessa TX 79762 Larry Brown Apple 11 microcomputers. 1. 2. 3. Denver Amateur Com- puter Society POB 1235, Englewood CO 80150 Lam,' Costa, (3031 1. 1. 3. 5. Permian Basin TRS-80 Users Group Rt #4, POB 1455, Odessa TX 79763 Allan D Emert, (915) 381-3138 TRS-80 Model 1. 4. 5. 1 428-2929 INTERRUPT We are a broad-interest dub. Southern Colorado Com- puter Club * WRITE OR CALL FOR FREE CATALOGUE * CALIFORNIA COMPUTER SYSTEMS Hir.HlNQU Mil) /< WIN PRh i 7.80 CPU 4 Mli/, wiili one serial port 12 slut S too mainframe disk controllei oil. Dynamic Ram, CP M2.2" $1,645. Interfaced to 2 Shugarl 8*, single sided double density drives mounted in our own beautiful MAX BOX with power suppl) and fan $1,250. A complete S-100 system for under $3,000 ("HE BES1 BLh ON ["HE MAR1 I I IMS 5000 and 8000 Systems Outstanding long term reliability and performani e I hese systems Feature a '80 A < I'l ' S 100 bus; ill ml ilc density drives (eithei single or double sided), DMA disl conti oiler, 64K RAM, 2 serial .s; I parallel port. Prices include the verj finest implementation <>l I I' \P available in the entire industry Hard disk .in/ DRIVES! Model 299B: Dual headed drives total I 2 MB unformatted $2,300. Model 277: I )iul 8 mcli drives voice coil positioned IBM compatible 16001 BYTES pel drive unformath d Si .210. Slimline abinel and power Foi eithi \ ' 7oi '■" ! $ (00 DRIVES [lie MAX BOX: Manufactured bj lohnD Owens \ iciates. 8 dual drive cabinel complete with powei supply .^ fan Will holdQumes Shugartsoi Siemen Excellent design and engineering . .. S 325. With 2 Shugarl 800 R drives St, 250. With 2 QUME Doubli sided drives St, 650. MPI 1551 $265. B52 U Bsi2 S500. Shugarl $ 450. HAZELTINE 1500 1510 S925. si 030 AMPEX DIALOGUE 80 CRT saso. Removable keyboard, 2 page memory M optional) bloi I- h ansinil CENTRONICS 737 $ '80 Same as I RS 80 Model IV Apple serial parallel interface $195. EPSON MX801S $ ISO IMS MEMORY u- K t.,tn $350. 32 K si. in, $650. 64 K Dynamic with parity $755. TEI MAINFRAMES, S 100 12 slot, table top $500. 22 slot, table top $670. Hack moiinls add $ 50. 50 Hj ' v volts add S 50. TELEVIDEO CRTs s>12 $780. s>20 $850. 950 $1,050. \AW CYPnDT Overseas Callers: TWX 710 588 2844 WttATUKi: Phone 212 448-6298 or Cable: OWENSASSOC JOHN D. OWENS Associates, Inc. 12 Schubert Street Staten Island, New York 10305 212 448-6283 212 448-2913 212 448-6298 Computer Shack, 1635 S Prairie, Pueblo CO 81005 Tom Thomas, (303) 564-3545 Monthly newsletter 1 . Utah Computer Associa- tion 2. 378 E 9800 S, Sandy UT 84070 3. Lawrence N Barney, (801) 571-9661 4. UCA Bits 5. Special interests: ad- vanced software, hard- ware, CP/M, and Pascal. 1. SNPCS (Southern Nevada Personal-Com- puting Society) 2. 1405 Lucilee St, Las Vegas NV 89101 3. Cy or Edna Wells, (702) 642-0212 4. Hard Copy 5. Both hardware and soft- ware; exchange id iiiim mation and experience; and guidance and en- couragement for new hobbyists. We participate in fairs and exhibitions. Zips 90000—99999 1 . Poly 88/8813 Users Group 2. 13022 Psomas Way, Los Angeles CA 90000 3. Pat or Roger Lewis 4. Poly 88/8813 Users Group Newsletter 5. Software exchange. 1. LA Apple Users Group 2. 9513 Hindry PI. Los Angeles CA 90045 3. Philip A Wasson, (2131 649-1428 178 April 1981 S BITE Publications In< 1. The San Fernando Valley 6502 Users Club 2. 3816 Albright Ave, Los Angeles CA 90066 3. Larry Goga, (213) 398-6086 5. This club is open to all owners of 6502-based computers including KIM, SYM, and AIM. PET and Apple owners are also welcome. 1. SuperLetter 2. Abrams Creative Ser- vices, 369 S Crescent Dr, Beverly Hills CA 90212 3. (213) 277-1588 5. Newsletter for SuperBrain users. 1. OSI Users Independent 2. 6061 Lime Ave #2, Long Beach CA 90805 3. Charles Curley, (213) 422-3673 4. OSI Users Independent Newsletter 5. OSI computers and soft- ware. 1. ELF of the Valley 2. 2670 Calle Abedul, Thou- sand Oaks CA 91360 3. Richard Cox, (805) 492-4128 5. RCA 1802 microcom- puters. 1. Compucolor/Intecolor Users Group 2. 5250 Van Nuys Blvd, Van Nuys CA 91401 3. Stan Pro, (213) 788-8850 4. Bulletin 5. We are an international group of color-computer users, with over 1000 programs in our library. 1. The Cursor Group 2. POB 266, North Hollywood CA 91603 4. The Cursor 5. User group of the Bally Arcade. 1. ET-3400 Users Group 2. 11231 Oak St, El Monte CA 91731 3. Charles Van Dyke, (213) 443-2237; CompuServe acct 70250,413 1. San Diego Heath User's Group 2. 12202 Kingsford Ct, El Cajon CA 92021 3. Jim Quinn, President, (714) 561-2540; Cliff Dudley, Secretary, (714) 697-8796 4. Coming soon 5. Special interests: the ex- change of ideas, informa- tion, and assisting Heath computer users. 1. CIE (Computer Informa- tion Exchange) 2. POB 158, San Luis Rey CA 92068 3. Bill McLaughlin, (714) 757-4849 4. CIE People's Software News 5. Special interests: TRS-80. 1. Apple for the Teacher 2. 9525 Lucerne St, Ventura CA 93004 3. David Miller, Editor, (805) 647-1063; Ted Perry, President, (916) 961-7776 4. Apple Educators' Newsletter 5. Education using Apple II microcomputers . 1. International Apple Core 2. POB 976, Daly City CA 94017 3. Ken Silverman, (415) 878-5382 4. The Apple Orchard * TELETYPE MODEL 43 INVENTORY SALE * TELETYPE Model 4320 AAA $ 885. 220V. model with transformer installed inside cabinet $ 985. Model 43ASR, 8 level, 1" tape . S2,595. Limited supply of Model 45 available. TELEBUFFER 43 ASR $945. Circuit card designed for internal instal- lation in the Model 43 Teletype. Changes the 43 into a buffered send/ receive device, enabling it to function as a Telex without paper tape. Provides from 4K to 16K bytes of internal mem- ory for storage of message. Contents of memory may be edited and manipulated in preparation for transmission. Options include forms control and answer back. IBM 3101 CRT Model 10 51,195. Model 20 $1,395. Selectric-like, detached keyboard. 9x16 dot matrix. Maintenance contract from IBM only $70 per year ITHACA INTERSYSTEMS Full S-100 IEEE Compatibility! Full 24 address bits. DMA disk controller. SYS- TEM 2A includes 20 slot mainframe with front panel, 64K Dynamic RAM. Z80 CPU, 4 MHZ, extended addressing capability. 4 parallel, 2 serial I/O floppy controller. Our discounted price, $3,415. MARINCHIP SYSTEMS M9900 Elegant 16 bit CPU, S-100 compatible, multi user, multi processor operating system. BASIC, FORTH, META, PAS- CAL, Word processor, text editor. CPU kit and software package . $ 550. Assembled $ 700. Complete system, 64KB, two drives $4,995. MICROANGELO $2,280. High resolution graphics system. 15", 22MHZ, green phospher screen, 72 key keyboard; includes complete cabling and software. From SCION. S-100 Graphics card $ 960. GRAPHICS SOFTWARE On line, real time, for the M9900 to drive the Microangelo. For use in design of PC board masks, IC masks and other applications $1,000. CORVUS HARD DRIVES We are the S-100 CORVUS dealer in the New York area. MODEL 11, Hard Disk System $4,820. Mirror Backup System $ 715. TARBELL Double density controller $420. Cables $ 40. Complete TARBELL Product Line Available. UPGRADE DEC LA 35/36 . $750. Increases baud rate to 1200. Micropro- cessor controlled. Many options avail- able. Enthusiastic user response. Long- term reliability. From DataSouth. Communications Software from from Hawkeye Grafix Enables communications from a micro to a terminal or to another micro, mini or maxi computer. Object Code $75. Source Code $250. 3M SCOTCH" Diskettes 5 BOXES 1 BOX Price of len per box Model 740,8" single sided, single density. .$29.00 $26.50 Model 741,8" single sided, double density. 38.00 35.00 Model 743,8" double sided double density. 46.50 42.50 Model744,5'/T soft sectored single sided, single density. . 29.00 26.50 CAT from NOVATION Originate/Answerback $175. CAT-D $185. Connects directly to telephone line with a plug-in jack. Eliminates need for acoustic coupler. AUTO-CAT $240. WE OFFER A FULL RANGE OF EXPERT CONSULTING SERVICES JOHN D. OWENS Associates, Inc. SEE OUR AD ON FACING PAGE April 1981 © BYTE Publications Inc 179 Clubs and Newsletters 5. Apple hardware and soft- ware. 1. Homebrew Computer Club 2. POB 626, Mountain View CA 94042 3. Robert Reiling, (415) 967-6754 4. Homebrew Computer Club Newsletter 5. Information exchange on all systems. 1. Proteus 2. 1690 Woodside Rd, 219, Redwood City CA 94061 1. FORTH Interest Group 2. POB 1105, San Carlos CA 94070 3. Roy Marteus, (415) 962-8653 4. FORTH Dimensions 5. The FORTH language. 1. San Francisco Apple Core 2. 1515 Sloat Blvd, Suite 2, San Francisco CA 94132 3. Randy Fields, (415) 775-7965 4. Cider Press 5. Apple computers. 1. CUssP 2. POB 784, Palo Alto CA 94302 3. Dave Dameron, Editor 4. CUssP Newsletter 5. Cromemco computers and systems. INSUA (International North Star User's Association) 2. POB 1318, Antioch CA 94509 3. William Banaghan 4. The Compass 5. For North Star computer users. 1. Arcadian 2. 3626 Morrie Dr, San Jose CA 95127 3. R Fabris, (408) 742-6048 (8 AM to 4 PM) or (408) 258-4586 (6 to 10 PM) 5. For the Bally /AstroVision Arcade. 1. CUE (Computer-Using Educators) 2. Independence High School, 1776 Education Park Dr, San Jose CA 95133 3. Don McKell, (408) 926-7378 4. Bimonthly newsletter 5. Computers in education. 1. Pascal/Z Users Group 2. 7962 Center Pky, Sacramento CA 95823 5. The purpose of our group is to encourage the use of Pascal. 1. 68XX(X) User Group 2. POB 18081, San Jose CA 95158 3. Ray Boaz, (408) 269-9522 5. All 68XX(X) microcom- puters and related hard- ware and software. 1. SYM-1 Users Group 2. POB 315, Chico CA 95927 3. H R Luxenburg, (916) 895-8751 4. SYM-Physis 5. Graphics, voice, music, word processing, and in- tercomputer communica- tions for the SYM-1. 1. Group/380 2. POB 1131, Mt Shasta CA 96067 3. Mokurai Cherlin 4. Group/380 News 5. IBM 370-compatible microcomputers . 1. The Aloha Computer Club 2. POB 4470, Kailua HI 96734 3. Roger Wickenden, Presi- dent, (808) 262-4673 4. The Debugga 5. Anything to do with microcomputers. 1. Z80 Microfans— A Sorcerer Users Group 2. POB 12504, Portland OR 97212 3. C Douglas Auburg, Editor, (206) 694-7769, evenings 4. Z80 Microfans Newsletter 5. Special interests: sharing problems, tips, and solu- tions in the use of the Ex- idy Sorcerer. 1. Portland Computer Society Inc 2. POB 17371, Portland OR 97217 3. Neal J Bonome, (503) 654-5932 4. Portland Computer Society Newsletter 5. Information exchange for all types of microcom- puters. 1. Salem Area Computer Club 2. POB 7715, Salem OR 97303 3. Kenneth Ernst, (503) 393-1173 4. SACC Newsletter 5. Users groups: Apple, TRS-80, PET, and VisiCalc. 1. Home Computers 2. POB 616, Silverton OR 97381 5. General information on personal computers. 1. Atari Computer En- thusiasts 2. 3662 Vine Maple Dr, Eugene OR 97405 3. M R Dunn, Editor, 4. A.C.E. Newsletter 5. This group is dedicated to the use of Atari microcomputers. 1. Hex Users Group 2. 36012 Military Rd S, Auburn WA 98002 3. Charles Worstell, (206) 927-6038 4. Newsletter on an ir- regular basis 5. Special interests: 6800 and 6809 small systems. 1. PN HUG (Pacific North- west Heath Users Group) 2. c/o POB 993, Bellevue WA 98009 3. Jan N Johnsen, (206) 464-5666 VAK-4 16K STATIC RAM BOARD • Designed specifically for use with the AIM-65, SYM-1, and KIM-1 microcomputers • Two separately addressable 8K-blocks with write protect. • Designed for use with the VAK-1 or KIM-4* motherboards • Has provisions for mounting regulators for use with an unregulated power supply • Made with 1st quality 2114 static ram chips • All IC's are socketed •' Completely assembled, burned-in, and tested We manufacture a complete line of high quality expansion boards. Use reader service card to be added to our mailing list, or U.S. residents send $1.00 (International send $3.00 U.S.) for airmail delivery of our complete catalog. "Product of MOS Technology VAK-4 DUAL 8K-RAM $Wfc6fr $325.00 plus shipping VAK-2 8K-RAM (Vi populated) $239.00 Special thru 4/30/81 VAK for $299.00 ^Jrnb> ENTERPRISES INCORPORATED 2951 W. Fairmount Avenue • Phoenix, AZ 85017 • (602) 265-7564 Please note new address 180 April 1981 © BYTE Publications Inc Circle 122 on inquiry card. This printer costs less than $450. Beat that... if you can. Epson This is the Epson MX-70. The lowest priced dot matrix printer you can buy. Now, that in itself should make it very attractive to a lot of people. But you ain't heard the half of it. To begin with, the MX-70 has a lot more in common with our now-famous MX-80 than just the name. Like unequalled Epson reliability. And technological breakthroughs like the world's first disposable print head. But frankly, the MX-80 packs a lot more power than some people need. So we built the MX-70 to be a no-frills print- er. At a no-frills price. But the MX-70 is still a great little printer. We give you 80 CPS unidirectional print- ing. Top-of-form recognition. Programmable line feed and form lengths. Plain paper printing. An easy-to-read 5x7 matrix. Self test. And an adjustable tractor feed. That's what you'd expect from a basic little printer. But here's something you wouldn't expect: the finest graphics package on the market today. Free. We call it GRAFTRAX II. And it means 480 dots across the page, resolution to 60 dots per inch, and a graphic image free of the jitter and overlap that plagues other printers. You get cleaner grays and finer point resolution. So now you've got a choice. You want more power and extra functions, you buy the MX-80. You want a basic little printer that prints, and keeps on printing, you buy the MX-70. They're both at your dealer now. But at this price, you'd bet- ter hurry. EPSON EPSON AMERICA, INC. 23844 Hawthome Boulevard • Torrance, California 90505 • (213) 378-2220 Circle 123 on inquiry card. BYTE April 1981 181 Clubs and Newsletters, 4. Newsletter published every other month 5. Special interests: Heath H-8 and H-89 microcom- puters. 1. NW PET Users Group 2. 2565 Dexter N #203, Seattle WA 98109 3. Richard Ball, (206) 284-9417 4. Newsletter 5. PET users group. 1. Apple Puget Sound Pro- gram Library Exchange 2. 304 Maine Ave S, Suite 300, Renton WA 98055 3. Dick Hubert, (206) 271-4514 4. Call-A.P.P.LE. 5. Everything related to the Apple II. 1. SPOHUG (Spokane Heath Users Group) 2. RFD #1, Box 676, Spokane WA 99204 3. Charles K Ballinger, President, (509) 448-9727 4. SPOHUG Newsletter 5. Special interests: Heath H-8 and H-89 computers. Foreign Clubs and Newsletters 1. Computer Education Group of Victoria 2. POB 245, Niddrie, Vic- toria 3042, Australia 3. Greg Johnstone, (03) 336-1855 4. COM-3 5. Educational uses of com- puters. 1. Brazilian Microcomputer Club 2. Rua Sambaiba, 516, Leblon, Rio de Janeiro 22450, Brazil 3. Douglas Gilson, 274-2439 5. Special interests: ex- changing programs and ideas with other clubs. 1. Apple's British Columbia Computer Society 2. #101-2044 W 3rd Ave, Vancouver, British Col- umbia, V6J 1L5, Canada 3. Gary Little, (604) 731-7886 4. Applegram 5. Apple II microcomputers. 1. Apple-Can 2. POB 696, Station B, Willowdale, Ontario, M2K 2P9, Canada 3. Louis H Milrad, (416) 961-6691 or 223-0599 4. Yes 5. All areas concerning microcomputers. 1. Association of Computer Experimenters 2. c/o B Murphy, 102 Mc- Craney St, Oakville, On- tario, L6H 1H6, Canada 3. B Murphy, (416) 845-1630 4. Ipso Facto 5. Special interests: CDP 1802 microprocessor- based hobby computers. 1. I-SUG 2. POB 1542, St Catharines, Ontario, L2R 7J9, Canada 5. Interested in Exidy Sorcerer microcomputers. 1. Kitchener — Waterloo Microcomputer Club 2. Reading Room — E2-3354, Electrical Engineering Department, University of Waterloo, Waterloo, Ontario, N2L 3Gl, Canada 3. Roger Sanderson, work (519) 885-1211, ext 3815 5. Special interests: 6800 and 6809 SwTPC systems. 1. OSMIE (Ontario Society for Microcomputers in Education) 2. Unit for Computer Science, McMaster University, Hamilton, Ontario, L8S 4K1, Canada 3. N Solntseff, (416) 525-9140, ext 4689 5. All educational uses of microcomputers. 1. The Ottawa Computer Group 2. POB 5691, Station F, Ot- tawa, Ontario, K2C 3M1, Canada 3. John Mainwaring, Presi- dent, (613) 725-9441; or Dennis Tubie, Secretary, (819) 561-1645 4. OCG Newsletter 5. Special interests: micro- processors and computer bulletin board. 1. TRACE (Toronto Region Association of Computer Enthusiasts) 2. POB 6922, Station A, Toronto, Ontario, M5W 1X6, Canada 3. Ross Cooling, (416) 488-3314 4. TRACE 1. CPE (Central Program Exchange) 2. Department of Com- puting & Mathematical Sciences, The Polytech- nic, Wulfruna St, Wolverhampton, WVI 1LY, England 3. Judith Brown, 0902 27371, ext 93 4. Program Exchange 5. Microcomputer usage in schools and educational computer-aided learning. 1. North London Hobby Computer Club 2. c/o D.E.C.E. Polytechnic of North London, Holloway Rd, London N7 8DB, England 3. Robin Bradbeer, 01-607-2789 4. Gigo 5. Special interests: business, homebrew, and games workshops. PET users group. 1. Microtel— Club 2. 9, rue Huysmans 75006 Paris, France 3. M Perdrillat, 33 (1) 544 70 23 4. Microtel-Infos 5. This group is interested in microcomputers and telecommunications . Bower-Stewart Si Associates SOFTWARE AND HARDWARE DESIGN $GOLD DISK$ CP/M Compatible Z-80 Software Available for all 8-5" SS-SD IBM format systems including TRS-80®, Northstar, SD Systems. Also available on 5" double density Superbrain." $175. ppd Un-can your canned software! Z-80 Disassembler Feel couped up with your canned software? Our Z-80 Disassembler recreates assembly language source files from absolute code enabling users to easily tailor programs to meet their specific needs. The Preconditioner works with the Disassembler to decode ASCII. Credit cards Immediate service, free 24 hr phone - we will credit invoice Checks. M.O.'s: Ten workday hold CA res Add tax $50. ppd ^B -^g Great looking letters & reports! E-Z Text A unique word processor organized around user-created text files, embellished with simple control commands, which supports such 'BIG GUYS' features as Automatic Foot- noting, Table Spacing, Heading, Paging, Left & Right Margins, Proportional Spacing and MORE, at a 'LITTLE GUYS' price tag. State system & controller Allow time for surface mail Trademarks Digital Research. Radio Shack. Intertec POST OFFICE BOX 1389 HAWTHORNE, CALIFORNIA 90250 213 / 676-5055 182 April 1981 © BYTE Publications Inc Circle 124 on inquiry card. The PRACTICAL MICROCOMPUTER PROGRAMMING™ books. . WHAT DO THE CRITICS SAY? BYTE: "It was apparently Mr. Welter's goal from the beginning to pre- sent the fundamental concepts of assembly language programming in a completely nonthreatening way. He has accomplished this better than any other author to date. . . Practical Microcomputer Program- ming is a very powerful series. It is well written and full of essential techniques for the assembly language programmer.". . . "The authors know the difference between a novice and a ninny. They never talk down. . . on every page the authors spot and clear up the small ambi- guities of technical jargon that can block understanding." Kilobaud: "A powerful plus for this book is the author's determination to demonstrate why and how to use each instruction, not merely to ex- plain how it works. . .At no point do the authors resort to rehashing material available from the manufacturer. . . but instead choose a less theoretical, more practical approach. " Leventhal: pies, and topics." ". . .large numbers of documented, well structured exam- a clear readable style, a logical development of major Digital Design: "This book is the best and most lucid introduction to Z80 programming that we have seen." CACHE: "This is an EXCELLENT book. . .dirt cheap for such great software and documentation." IF YOU'VE TRIED THE "CHEAPIES" AND AREN'T SATISFIED WITH WHAT YOU GOT, IT'S TIME TO TRY THE REAL THING, THE ACKNOWLEDGED WORLD STANDARD OF TECHNICAL EXCELLENCE IN ASSEMBLY LANGUAGE PROGRAMMING INSTRUCTION— THE PRACTICAL MICROCOMPUTER PROGRAMMING BOOKS. - FOR THE 6502 ■ PRACTICAL MICROCOMPUTER PROGRAMMING: THE 6502 toy W. J. Weller $32.95 20 chapters, 6 appendices, 475 page Smythe sewn hardcover covering all fundamental assembly language techniques for the 6502 processor. The text explanation is re-enforced with 1 18 verified, real world programming examples that run on real computers. An extended 6502 language, sup- ported by a new editor/assembler which comes with the book, circumvents many of the problems which have made the 6502 so difficult to pro- gram in the past. In addition to the fundamental technique chapters, there are special chapters covering simple graphics, elementary cryp- tography and random number generation and use. The source texts of both the editor/assembler and a powerful new debugging monitor for the Ap- ple II and Apple II + included in appendices. The object code for this software is supplied FREE to book purchasers on Apple cassette or for $7.50 on disk when the licensing agreement from the book is returned to the publisher. The editor/assembler is also available on paper tape for users of other 6502 based systems. - FORTHEZ80- PRACTICAL MICROCOMPUTER PROGRAMMING: THE Z80 toy W.J. Weller $32.95 18 chapters, 4 appendices, 481 page Smythe sewn hardcover which details assembly language technique as applied to the Z80 processor. The Z80 is treated as an 8080 superset in an 8080 extension language, which means that you don't have to discard your hard won 8080 knowledge to pro- gram the 180. In addition to the fundamental chapters there are chapters on graphic output and full four function decimal arithmetic. The text ex- planation is re-enforced with 104 tested, verified programming examples. A powerful editor/assembler and debugging monitor, in source form, are provided to support the language used in the book. This software will run on any 280 based computer with 1 0K RAM beginning at 0. Object code for both editor/assembler and debugging monitor is sent to book purchasers FREE on paper tape or, in modified form, on TRS-80 Level II cassette when the coupon from the book is returned to the publisher. ■ FOR THE 8080 - PRACTICAL MICROCOMPUTER PROGRAMMING: THE INTEL 8080 toy Weller, Shatzel and Nice $23.95 18 chapters, 3 appendices, 318 page Smythe sewn hardcover which applies fundamental assembly language technique to this most popular of processors. The text is supported by 84 separate programming examples. The book includes a special section on the handling of complex peripheral devices and exotic typefaces. Appendices give the source for an 8080 resident debugging monitor and a minicomputer cross assembler for the 8080. Also available (not shown above) are a workbook for use with this text ($9.95) and Mi EDITOR/ASSEMBLER SYSTEM FOR 8080/8085 BASED COMPUTERS ($15.95) which supports the language used in the text. These three books together make a complete teaching package for the 8080. • FOR THE 6800 ■ PRACTICAL MICROCOMPUTER PROGRAMMING: THE M6800 toy W.J. Weller $23.95 16 chapters, 2 appendices, 299 page Smythe sewn hardcover text which details the application of fundamental assembly language technique to the 6800. 104 separate programming examples re-enforce the text explanation. Contains in addition special chapters on low precision trigonometry and random number generation and use. A resident debugging monitor for 6800 systems is included in an appendix. NO GAMES, NO NONSENSE, NO RE- | PRODUCTIONS OR REHASHES OF | MANUFACTURER'S DATA SHEETS, | JUST TESTED, ACCURATE, RELE- | VANT PROGRAMMING INFORMA- | TION BACKED UP BY REAL EXAMP- | LES THAT RUN ON REAL COMPUT- | ERS-THE PRACTICAL MICROCOM- | PUTER PROGRAMMING BOOKS, i THERE IS NOTHING ELSE AS GOOD i ANYWHERE, AT ANY PRICE. Mail to: Northern Technology Books, Box 62, Evanston, IL 60204 □ Practical Microcomputer Programming: The 6502 □ Practical Microcomputer Programming: TheZ80 □ Practical Microcomputer Programming: The Intel 8080 □ Practical Microcomputer Programming: The M6800 D Workbook for Practical Microcomputer Programming: The Intel 8080 □ An Editor/Assembler System for 8080/8085 Based Computers $32.95 $32.95 $23.95 $23.95 $ 9.95 $15.95 D Check enclosed (U.S. funds only) Name Street City D Money order enclosed . State -Zip Illinois residents add 5% sales tax The time has come for computers to talk and listen ^ Introducing COGNIVOX series VIO, the affordable voice I/O peripherals If you have a PET - TRS-80 - APPLE II AIM 65 - SORCERER or any Z-80 CPU based system with at least 1 6K ol RAM, COGNIVOX will add a whole new dimension to your computer. Imagine being able to use your voice for entry of commands and data and then listen to the computer talk back to you! This exciting possibility has now become a reality at a very affordable price. COGN I VOX. series VIO, is a family ol voice input and output peripherals especially designed for personal computers that are easy to use and have excellent software support. You need only plug in COGNIVOX, load one ol the programs provided and you will be able to have a voice encounter with your computer 1 COGNIVOX can be trained to recognize words or short phrases from a vocabulary of up to 32 entries of your choice, with an accuracy of up lo 98%. The voice response vocabulary can also have up to 32 entries chosen by the user. COGNIVOX requires that your computer has at least 16K of RAM. If it has less memory or if you are only interested in recognition, ask us about our SR-100 series of voice input peripherals COGNIVOX comes complete with microphone, power supply, (as required), built-in amplifier/speaker and extensive user manual. What makes COGNIVOX truly unique, though, is the software that comes with it on cassette. Some of the programs included are: DIALOG, a program that lets you conduct a dialog with your computer (or translate from one language to the other); VDUMP, a vocal memory dump that reads the memory contents out loud; VOTH, a voice operated talking board game and VOICETRAP, a voice operated video game. Adding voice I/O to your own programs can be done very easily too. All that is needed to have your computer recognize a word or say a word is a single USR statement in BASIC. No machine language programming is necessary. With all these features, you'd expect COGNIVOX to cost a small fortune (after all, even talking chess games sell for over $300), yet it only costs $149 (add $4.50 fcr shipping in the U.S., 10% ol order overseas. CA res. add 6% tax). This low price has been made possible by innovative hardware and a technological breakthrough in recognition algorithm design that uses powerful non-linear pattern matching techniques and adaptive learning. COGNIVOX is simply the most (un, most exotic peripheral you can buy for your computer. Write or call (805) 685-1854 for more information. giving us the make and model of your computer Or better yet. order a COGNIVOX today and bring your computer to life. VOICETEK Dept B, P.O. Box 388 Goleta, CA 93116 Clubs and Newsletters , 1. Japan Microcomputer Club 2. Rm 313, 3-5-8, Shibakoen, Minato-Ku, Tokyo 105, Japan 3. Keigo Aono, Director 03-438-1869 4. Microcomputer Circular 5. This is the largest, non- profit, nationwide group in Japan. An English-lan- guage version of the club's newsletter is available. Microcomputer Club Fte de Quijote §5, Tecamachalco, Mexico 10-D F, Mexico Alfredo Buzali, (905) 589-2279 Bulletin Primarily concerned with the Apple computer. 1. HCC (Hobby Computer Club) 2. Christinastraat 171, 5 615 RK Eindhoven, Nether- lands 4. Hobby Computer Club Nieuwsbrief 5. The goals of the HCC are to increase contacts be- tween computer amateurs and to exchange ideas and experiences. 1. Club de Com- putation Lampas de Carabobo 2. Apartado 716, Valencia, Venezuela 2001A, Venezuela 5. Use of microcomputers in civil engineering, basic sciences, and administra- tion. ■ A nswers to Micro Shakespeare Quiz 1 -m 2-j 3 -a 4-f 5-h 6 - 7- 8 - 9 - 10 - b q l s 11 - i 16 - e 12 - c 17 - t 13 - r 18 - k 14 - g 19 - n 15 - p 20 - d Number of Correct Matches MicroShakespeare Rating 20 Hit "START" with con- fidence. 17- 19 One short debug session and you're home free. 13 - 16 Check your system monitor. 9-12 Must have mixed up the pin- outs. 5 -8 Blame it on a power surge. 4 or fewer Back to collecting stamps. ■ 184 April 1981 © BYTE Publications Inc Circle 14 on inquiry card. SOLVE THE STORAGE SHORTAGE with ten multi-user megabytes CompuStar's 8-inch Winchester CompuStar Cable Assembly If you could think of just one way to im- prove our phenomenally popular Super- Brain, what would it be? More disk storage? Well, we already thought about it. And for only a few thousand dollars for a whopping 10 megabytes of lightning- fast storage, it's nothing short of another major breakthrough! From the company that wrote the book on price/perfor- mance . . . Intertec. Our New CompuStar™ 10 Megabyte Disk Storage System (called a DSS) features an 8 inch Winchester drive packaged in an attractive, compact desktop enclosure. Complete with disk, controller and power supply. Just plug it into the Z80 adaptor of your SuperBrain and turn it on." It's so quiet, you'll hardly know it's there. But, you'll quickly be as- tounded with its awesome power and amazing speed. 'Some models require hardware/software modification. The secret behind our CompuStar DSS is its unique controller/multiplexor. It allows many terminals to "share" the resources of a single disk. So, not only can you use the DSS with your Super- Brain, you can configure multiple user stations using our new series of Compu- Star™ terminals, called Video Processing Units or VPU's™. Four CompuStar VPU's are available. At prices starting at less than $2,500. Some models are designed to operate as stand-alone microcomputers, with inter- nal disk storage. Just like your Super- Brain. Each model features its own 64K of RAM and can be "daisy-chained" into a powerful multi-user network. Just connect one VPU into the next. Using easy-to- install cable assemblies. Connect up to 255 users in a single system. One at a time. As you need them. Whether you need an extra 10 megabytes for your SuperBrain or an enormous multi-user network, the CompuStar™ DSS solves your storage shortage problems. Sensibly. And economically. Plus, your investment is protected by a nationwide service net- work with outlets in most major U.S. cities. Providing efficient on-site or depot maintenance. Get a demonstration of this extraor- dinary new system today. Call or write now for the name and address of your nearest CompuStar dealer. j= INTERTEC Cdata s systems. 2300 Broad River Rd. Columbia. S.C. 29210 (803) 798-9100 TWX: 810-666-2115 THE EGYPTIANS LOVED LARGE NUMBERS, AND... ts THE GREEK-5CAME UP WITH A WHOLE 5ET OF VARIABLES: THE A LPHABET loo^zoei/) (wov?)j PEOPLE COULD NOW HAVE A HARD COPY OF ANYTHING. IT WAS EVEN USED BY OUR FOUNDING FATHERS. BUT WHEN REPLACING TUBES BECAME MORE COSTLY THAN THE FIGURING WAS WORTH, SOLID STATE TECHNOLOGY TOOK OVER. SO INSTEAD OF MASSIVE COMPUTERS FILLING UP AN ENTIRE FLOOR, THEY WERE BUILT TINY. ABOUT THE SIZE OF A REFRIGERATOR. FINALLY CAME THE IN VENT I ON OF THE MICRO- PROCESSOR! BACK IN PRE -HISTORIC TIME5 5 CAVEMEN DID ALL THEIR FIGURING ON THEIR FINGERS. BUT THE ONLY TROUBLE WAS 10 WAS AS HIGH AS THEY COULD COUNT LET5 5E£ WOW. TWEy/M »s...UH,HMM .W/ELL.ITMuoTBE 10 * SO THEY INVENTED A CRUDE ADDING MACHINE COUNTING REMAINED THAT WAY UNTIL SOME GREAT SUMERIAN DISCOVERED THAT NUMBERS] CAN EXIST HIGHER THAN lO. IT EVEN HAD ITS OWN SET OF GRAPHIC CHARACTERS. AS TIME PROGRESSED 50 DID MAN'S NEED FOR I EVEN MORE COMPLICATED) NUMBER WORK. o , THE CHINESE PUT IT TO IMMEDIATE (J5E THEN PASCAL INVENTED THE BUILT IN POWER SUPPLY. WITH THAT, THE FIRST TRUE DIGITAL C0MPUTER5 WERE BUILT. THEY WERE GIANT AND USED MILLIONS OF TUBES. G-UTENBERG INVENTED THE F/R5T MOVABLE PRINT. HEAD- - OO o o o o a o O 4 % % \\f % rare #88® DESPITE THEIR SMALL SIZE, THEY STILL WERE NOT QUITE SMALL ENOUGH --FOR HOM E US E. GET THAT TWINS Ol/T OF M* HoWE' WHICH MADE IT POSSIBLE -H FOR MICRO-SIZE COMPUTERS WflWi/jniH»«n///fJ»||| f|| " AND NOW OUR 5MALL PORTABLE COMPUTERS ARE THOUSANDS OF TIMES MORE POWERFUL AMD C05T T THOUSANDS OF TIMES LESS. r — ^ * FACT: BfN FRANKLIN COINED THE ELECTRICAL TEftMJ "POSITIVE AND N64ATIVE'' 30 NOW IT IS EASIER THAN EVER TO WRITE A COMPLICATED PRO&Ri 186 April 1981 © BYTE Publications Inc Circle 127 on inquiry card. Orange micro CENTRONICS 737 ( RADIO SHACK \ LINE PRINTER IV ) Word Processing Print Quality • 18 x 9 dot matrix; suitable tor word processing • Underlining • proportional spacing • right margin justification • serif typeface • 50/80 CPS • 9V2" Pin Feed/Friction feed • Reverse Platen • 80/132 columns CENTRONICS 737-1 (List $995) $765 CENTRONICS 737-3 (List $1045) $815 EPSON MX80 I Low-Priced Professional Print Quality • 9 x 9 dot matrix • Lower case descenders • 80 CPS • Bidirectional, Logic seeking • 40, 66, 80, 132 columns per line • 64 special graphic characters: TRS-80 Compatible • Forms handling • Multi-pass printing • ad- justable tractors EPSON MX80 EPSON MX70 .(List $645) .(List $495) OKIDATA MICROLINE SERIES TRS-80 Graphics Compatibility • 9 x 7 dot matrix • 80 CPS • 80, 132 columns — 64 shapes for charts, graphs & diagrams • Double wide characters • 6/8 lines per inch • Up to 3 part copy • Friction & pin feed • 200 M character head warranty OKIDATA MICROLINE 80 (List $800) $520 OKIDATA M82 Bidirectional, Forms handling (List $960) $750 OKIDATA M83 Wide carriage, 9 x 9 dot matrix (List $1 260) Scall IDS PAPER TIGERS Dot Resolution Graphics, quality print • 7 wire printhead (445); 9 wire printhead (460) with lower case descenders • Over 150 CPS • bi-directional, logic seeking (460) • 8 character sizes; 80-132 columns • Adjustable tractors • High-resolution dot graphics • Proportional spacing & text justification (460). IDS445G 7 wire printhead, graphics (List $895) IDS460G9wire printhead, graphics (List $1394) $ 795 $1150 CALL FOR FREE CATALOG (800) 854-8275 CA,AK, HI (714) 630-3322 At Orange Micro, we try to fit the right printer to your application. Call our printer specialists for free consultation. 'SPECIALIZING IN PRINTERS AND CRT'S" VISTA — C. ITOH Daisy Wheel Letter Quality • 25 CPS (Optional 45 CPS) • Typewriter quality • Centronics parallel • RS 232 Serial (Optional) • Proportional spacing • Bidirectional • Programmable VFU • Self test • Diablo compatible • Friction feed (Optional tractors) • 136 printable columns. • Manufactured by C. ITOH. VISTA V300 (C. ITOH) (List $1895) $ Call ANACOM Low Cost, High Speed, Wide Carriage • 9 x 9 dot matrix • Lower case descenders • Wide carriage • Adjustable tractors to 16" • 150 CPS, Bidirectional, Logic Seeking ANACOM 150 (List $1 350) S Call ANADEX Dot Graphics, Wide Carriage • 11 x9dot matrix; lower case descenders • Dot resolution graphics • Bi-directional, logic seeking • Up to 200 CPS • RS 232 Serial & Parallel • Forms control • X-ON/X-OFF* Up to 6 part copy. ANADEX9501 (List$1650) $1450 NEC SPINWRITER High Speed Letter Quality • 55 CPS • Typewriter quality • Bidirectional • Plotting • pro- portional spacing. 5510-5 RO, Serial, w/tractors (List $2995) $2625 5530-5 RO, Parallel, w/tractors (List $2970) $2599 QUANTITY PRICING AVAILABLE TELEVIDEO CRT'S PRICES SLASHED! TVI912C TV I 920C TVI 950 } Please Call Toll Free Prices are too low to advertise PRINTERS MALIBU 1 65 wide carriage, graphics, letter quality .. (List $2495) $1975 QUME 5/45 typewriter quality (List $2905) $ 2559 INTERFACE EQUIPMENT CCS APPLE PARALLEL Interface & cable $ 150 | APPLE II- EPSON MX80 parallel graphics intertace board & cable $ 110 SSMAIO BOARD Apple Serial/parallel interface (List $225)$ 175 MICROTRONICS Atari parallel interface $ 69 I ATARI 850 Interface module, serial/parallel $ 199 TRS-80 CABLES to keyboard or Exp. interface * Ca " NOVATION D-CAT direct connect modem $ Call TELEPHONE ORDERS: Mon.-Fri. 8:30 - 5:00 The Orange Micro Printer Store (Retail): Mon. -Fri. 10:00 - 6:00, Sat. til 4:00 *Ss Phone orders WELCOME; same day shipment. Free use of VISA & MASTERCARD. Personal checks require 2 weeks to clear. Manu- facturer's warranty included on all equipment. Prices subject to revision. Oronge fTlfCrO, Inc.' 3148 E. La Palma, Suite E Anaheim, CA 92806 Software Review Three Versions of APL Gregg Williams, Senior Editor BYTE POB 372 Hancock NH 03449 When BYTE magazine published its APL language issue in August 1977, APL was far beyond the capabilities of any microcomputer. To show how rapidly things have evolved since then, the Digital Group, in that same issue, was advertising a 32 K-byte static-memory board for $995, and another advertisement began, "Introducing Apple II...." Times have changed: 32 K bytes of dynamic memory, now commonly used in several major micro- computer lines, can be bought for less than $120 — and Apple is one of the oldest computer lines in the industry. Times have changed for APL as well: several com- panies have announced software and hardware support- ing this unique programming language. This review com- pares three versions of APL: Softronics APL, Ramware APL80 for the Radio Shack TRS-80, and Vanguard APL/V80. (For additional information, see the "At a Glance" boxes. Tables 1 thru 4 give timing comparisons and further information.) Softronics APL: I/O Options and Documentation Softronics APL runs on any Z80-based computer that supports at least 44 K bytes of memory and the CP/M operating system. It was written by Eric Mueller of Soft- ronics, who, in 1977, authored a subset of APL called EMPL for 8080-based microcomputers. Softronics APL (Version 2.3C), which sells for $350, has both good and bad features; a summary is given in table 2. The most welcome feature of Softronics APL is the ability to use it with several types of keyboards and display devices. The default mode of operation is for the software to respond to a standard ASCII (American Stan- dard Code for Information Interchange) terminal through standard CP/M input and output routines. Three other modes allow the user to use an assortment of APL-type devices. For those of us who do not have several thousand extra dollars to spend on an APL-type I/O (input/output) device, the ASCII mode of Softronics APL is very welcome. In this mode, all APL characters that are not on a normal keyboard are replaced by either a single key (eg: an underline character to replace the APL assignment ar- row) or a 3-character mnemonic (eg: $TP for the transpose operator or $RO for the Greek rho symbol). Although some users object to this arrangement, my reaction to running Xerox APL for an extended period, using such mnemonics, was one of gratitude — better this APL than no APL at all. Listing 6 shows the output of the APL function CIRCLE. Listing 3a shows the output with slight changes in regular APL notation. I have also found that by chang- ing the value of the system variable DCS, you can cause the APL mnemonics to be displayed with angle brackets around them instead of the preceding dollar signs — on printout only (ie: not input). For example, you will still have to type in $RO for the APL reshape operator, but it will be displayed to the screen or printer as < RO> . This is a nice feature that adds to the readability of APL pro- grams printed in ASCII mode. Provisions are also made for using Softronics APL with the two most prevalent types of APL terminals (bit- pairing and typewriter-pairing terminals). Softronics APL begins executing in the ASCII mode but can be con- verted to APL terminal mode by assigning a new value to the system variable DCS, or it can be modified to begin executing in terminal mode by making a 1-byte patch to the APL.COM machine-language file. Nonstandard ter- minals or video boards can be interfaced by adding user- supplied input and output machine-language subrou- tines. The manual explains what routines need to be writ- ten and where they should be placed in memory. Finally, the manual gives documentation on still another I/O option: the use of APL input and output through a video board with a programmable character generator. The documentation includes the software driver (which works with an Objective Design Inc character generator), a Kent-Moore Alpha-VDM-II video display board, and a listing that defines all APL special characters for a character generator as a series of hexa- decimal numbers. All this code is included in the APL.COM file. The ease with which I understood these four display options is an indication of the quality of the documenta- tion. The Softronics APL documentation is the best of the three packages reviewed here. It includes a short tutorial on APL for the complete novice, a description of all func- tions, sample programs (including APL defined functions that simulate certain APL operators not defined in ma- chine language), and several useful appendices. One sec- tion of the documentation, "Bugs and Common Perplex- ing Error Messages," is a great time saver. It is extremely helpful in explaining some quirks of Softronics APL and how to circumvent them. This section saves the user from 188 April 1981 © BYTE Publications Inc Circle 128 on inquiry card. The VP-111 hobby computer: Start programming for only $ 99. $99. New! VP-111 Microcomputer Assembled* and tested. Features: • RCA 1 802 Microprocessor. • 1 K Bytes static RAM. Expandable on-board to 4K. Expandable to 32K Bytes total. • 51 2 Byte ROM operating system. • CHIP-8 interpretive language or machine language programmable. • Hexidecimal keypad. • Audio tone generator. • Single 5-volt operation. • Video output to monitor or modulator. • Cassette interface— 1 00 Bytes/sec. • Instruction Manual with 5 video game listings, schematics, CHIP-8, much more! Ideal for low-cost control applications. Expandable to full VP-71 1 capability with VP-114Kit. 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So f Ironies APL: Some Problems Despite its excellent performance in other areas, Softronics APL (Version 2.3C) has a number of deficien- cies that range from minor annoyances to critical defects. The most serious defect is that Softronics APL does not notify the user of an error situation. Any computation that has a result over 9.2 X 10 18 is replaced by a seemingly random value between 10 18 and 10 19 . The low limit on computation size is not what makes this error dangerous; rather, the danger lies in the language substituting an in- accurate answer and not stopping the computation with an error message. A second problem with Softronics APL is that it re- sponds with the message SYNTAX ERROR to any num- ber over 7 digits long. I feel that the inability of this language to accept a longer number by rounding it off and, when necessary, putting it into scientific notation is a serious defect. Many numeric operations that should come out "even" result in numbers ending in ...9999 or ...9997. For example, any variable assigned either the value 0.1 or 1/10 is printed as .099999. The dyadic power function has, for integral exponents, a cumulative round-off error that results in some incorrect answers. For example, 5 s is calculated to be 390,622 (it is 390,625) and 3 12 is calculated to be 531,436 (it is 531,441), with higher powers also being incorrect. IEEE-488 TO TRS-80* INTERFACE Everything needed to add powerful basic GPIB-488 controller capability to TRS-80 Model 1 or 3, Level 2 or DOS with a minimum of 16K. MODEL 488-80B For Model 1 Operation Jl MODEL 488-80C For Model 3 Operation Price of Model 488-80B or 488-80C $225. + shipping, insurance & tax Optional Relocatable Machine Level GPIB Driver for Assembler Level Programming-$35.00 WHEN ORDERING SPECIFY DISK OR TAPE SCIENTIFIC ENGINEERING LABORATORIES 11 Neil Drive • Old Bethpage, NY 11804 Telephone: (516) 694-3205 'Trademark of Tandy Corp. There is no affiliation between Scientific Engineering Laboratories and Tandy Corp. or Radio Shack. When using the power function for fractional powers, such as square roots, the results seem to be one or two units off in the least significant digit. Even though 6 significant digits are given in all calculations, I would recommend using only 5 significant digits when using the dyadic power function to calculate a root. The trigonometric functions, such as sine, cosine, tangent, and arctangent, agree with the results found in the Chemical Rubber Company's CRC Standard Math- ematical Tables. However, the arctangent function seems to work with a scalar (ie: a single value) but not with a vector (ie: a one-dimensional array of values). Softronics APL still lacks several useful functions that are found in the more expensive Vanguard APL: arc- cosine, arctangent, and all hyperbolic trigonometric functions; rotation on three-dimensional and higher matrices; the grade-up and grade-down functions; and the deal (ie: dyadic question-mark) function. Other, Name Language Used Softronics APL, Version 8080 machine language 2.3C Computer Needed Type of Software An 8080-, 8085-, or Package Z80-based computer with Version of APL program- at least 44 K bytes of ming language programmable memory, running the CP/M Manufacturer operating system Softronics, 35 Homestead Ln, Roosevelt NJ 08555 Documentation 112 pages, 22 by 28 cm Price ifiVi by 11 inches) $350 Audience Format APL users, programming 8-inch standard CP/M language enthusiasts floppy disk Name Computer Needed APL80 (by Phelps Gates) Radio Shack TRS-80 Model I with one floppy- Type of Software disk drive, Level II Package BASIC, and 32 K bytes Version of APL program- of memory ming language Documentation Manufacturer Twenty pages, 13 by 20 Ramware, 6 South St, cm (5 by 7 3 A inches) Milford NH 03055 (603) 673-5144 Audience APL users, programming Price language enthusiasts $39.95 Comments Format Cassette-tape version 5-inch floppy disk with 25% fewer features available for 16 K Language Used TRS-80 at $14.95 Z80 machine language 190 April 1981 © BYTE Publications Inc Circle 129 on inquiry card. standard on our 900 SERIES microcomputer system ... under $ 4,000.0O* Having so much disk capacity as standard in a low cost microcomputer system is reason enough to make the 900 Series your logical choice — but the fact is, it's only one of the reasons why this system offers the best price/performance value of any now on the market. 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DESIGNED FOR OPTIMUM RELIABILITY AND EASY SERVICING Single board design Quad-density flexible disk drives Turn-key operation and security Expansion capabilities Industrial quality construction 'In OEM/Dealer quantities, please contact factory for pricing detail. CP M " is a registered trademark of Digital Research OPTIONS FOR THE 900 SERIES: □ Disk expansion: up to 5 Mb formatted capacity. □ Serial I/O expansion: two additional RS232 ports (serial printer, modem, etc.) □ S100 bus adaptor for system expansion. □ Multi-user operation □ Hard disk subsystem □ OASIS operating system AVAILABLE SOFTWARE FOR THE 900 SERIES: □ High level languages include: BASIC, FORTRAN, COBOL and PASCAL. □ Application packages include: Inventory, Word Processing, GL, AR, AP and Payroll. the Quay 900 Microcomputer System offers the most complete package for the money QUA3 CORPORATION P.O. Box 386, Freehold, New Jersey 07728 ■ (201 ) 681 -8700 Factory: Route 34, Wall Township, New Jersey 0771 9 DISTRIBUTOR AND REPRESENTATIVE INQUIRIES WELCOME Circle 96 on inquiry card. more advanced operators that are also missing are not mentioned here. See table 2 for a more complete defini- tion of the language. Ramware APL80 In its version of APL for the Radio Shack TRS-80 Model I, Ramware of Milford, New Hampshire, has made available a remarkable product. When I first saw the advertisements for the tape version of APL80, its low price ($14.95) led me to dismiss it as some kind of toy, probably written in BASIC and too slow to be useful. Even though the tape version has about 25% fewer features than the more expensive disk version ($39.95), it is still written in Z80 machine language and is a fairly usable version of the language. Author Phelps Gates has reason to be proud of this package. Table 3 lists the operators available within APL80. The fullness of the language is due to the use of the ROM (read-only memory) modules implementing Level II BASIC. Because the author was able to use the numerical routines from Level II BASIC, much of the work of creating an entire programming language had been done for him, and he could concentrate on making it behave like APL. (APL80 has been tested and found to work on the newer TRS-80s that have Level II BASIC in two rather than three ROM devices. Until a correction can be made to the current version of APL80, however, the down-arrow symbol used for the APL drop and grade- down operations must be displayed by simultaneously Text continued on page 196 FOOLPROOF P. C. BOARDS WITH RE-ZOLV® PAT PEND THE COVAL IMAGING PROCESS Negative or Positive Coat your own p. c. board with this unique photo-resist. Environmentally safe. Develops in water. No toxic or corrosive chemicals. Work in room light. Temperature control is not critical. 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Kirby, Champaign, IL 61820 Name of System Features Vanguard APL/DTC APL/ASCII keyboard (desk-top computer) and 12-inch APL/ASCII memory-mapped video Manufacturer display of twenty-four Vanguard Systems Cor- 80-character lines housed poration, 6812 San in separate video terminal Pedro, San Antonio TX enclosure; display of all 78216 (512) 828-0554 APL characters Price Software Included $7995 CP/M operating system, APL/DTC software Terminal Dimensions 32 by 45.5 by 53.5 cm Hardware Options (12 Vi by 18 by 21 Communications option inches) (Hayes Microcomputer Products Micromodem Computer Dimensions plus special software); 19 by 51 by 43 cm {7V% high-resolution by 20 by 17 inches) (256-by-240 black-and- white or 128-by-120 Processor sixteen-gray-level ) Z80, 8-bit graphics; letter-quality APL/ASCII printer, real- System Clock Frequency time clock. 4 MHz Software Options Memory APL * PLUS file system 80 K bytes of static simulator memory (34 K bytes left for APL workspace) Audience APL users, programming- Mass Storage language enthusiasts Two quad-density 5-inch floppy-disk drives Name mable memory; a Z80 Vanguard APL/V80 processor card; at least one floppy-disk drive Type of Software Package Documentation Version of APL program- Seventy-six pages, 22 by ming language 28 cm (8V2 by 11 inches) Manufacturer Audience Vanguard Systems Cor- APL users, programming poration, 6812 San language enthusiasts Pedro, San Antonio TX 78216 (512) 828-0554 Features APL defined functions Price (programs) simulate some $500 APL functions, APL * PLUS file system, and Format other functions CP/M or CDOS operating system, 5-inch Comments or 8-inch disk This version is identical to the software reported Language Used on for the APL/DTC Z80 machine language computer, except for the reduced workspace size Computer Needed and the availability of the Computers with at least inner product function as 48 K bytes of program- a defined function. 192 April 1981 © BYTE Publications Inc Circle 130 on inquiry card. 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RETRIEVAL TIME: Average less than 5 seconds for any of 1000 records. NUMBER OF FIELDS: defined by user. RECORD LENGTH: Defined by user. FILE SIZE: Determined by record length and disk capacity. Keyfield(s): Specified by user. Soon to be released PASCAL tutorial Insurance Rating Program Client Information System Metric Education Program INTRODUCTORY OFFER You can get the EVANS BUSINESS SYSTEM software package for $99.95 or an EVANS BUSINESS SYSTEM demo copy (free for your in- home inspection), at your nearest Software-To-Go dealer. If not yet available at your favorite computer store send: $99.95 for the package, $15.00 for the demo copy (creditable towards the package purchase). SOFTWARE-TO-GO 2000 Guadalupe Austin, Texas 78705 512-472-8926 Z •DEALER INQUIRIES INVITED* Listing 1: Listing of the APL function SETUP. This routine defines certain variables used in the execution of benchmark programs. V SETUP [10] A-i-10 lOpilOO [20] B*M [30] OlOxloiM [40] D+-A*(°2)ilOQ [50] E+llO [60] F+-1000 365 24 60 60 [70] RA^,A [80] RB+.B [90] M3D<-2 5 lOpRA V Listing 2: Listing of the APL function TIME. When this routine is used as a benchmark program, the function to be tested replaces each occurrence of the phrase (EXP) on lines 10 thru 60. (See table 1.) V TIME N;LP [10] LP+0 [20] BGN-.(EXP) [30] (EXP) [40] (EXP) [50] (EXP) [60] (EXP) [70] ^(N>LP^LP+1)/B0N [80] 'DONE ';/Jx5;' TIMES' [90] 'UNIT TIME IS '; (4ffx5)x[]; 1 SECONDS PER ITERATION' V Listing 3: Listing and sample execution of the APL function CIRCLE. Listing 3a shows the function, which has the purpose of adding a set value to all matrix elements that fall within an imaginary circle with a given center and radius. Listing 3b shows a 10 by 10 array filled with zeros and, below it, the same circle after execution of the statement B— (6 5 4 8) CIRCLE A. On one of the printers used to generate these listings, the backarrow character, — , appears as an underscore, VB+-AR CIRCLE A ;RD;ROW;COL [10] AR CONTAINS: ROW COORD, COL COORD, RADIUS, VALUE ADDED [20] B^A [30] BCW*-/!fl[l]-/lJ?[3] + l [40] NEXTROW: ROWi-ROW+1 [50] CO/>vli?[2]-/«?[3] + l [60] NEXTCOL: C0L*C0L-H [70] ->(ARl3~]<(((ROW-ARlll)*2) + (COL+ARL2'})*2)*Q.5'i/ENDLP [80] BlROW;COL1*BLROW ,C0L]+/lfl[4] [90] ENDLP:-+(COL-(0,NEXTROW)[l+ROWB 0.48 0.42 0.091 Q-B 0.059 0.051 0.012 Q— 20D 5.0 2.9 8.6 Q — $C 140. 11. 3.1 Q~FT100000000 NA 0.61 0.13 Q — _ 50tRA 0.086 0.18 0.014 q-ODni 180. NA 66. Q — 4[l]M3D NA 0.74 1.8 Q— E°.+ E 0.41 0.31 0.082 Q—+/C 0.25 0.25 0.19 CIRCLE 160. * 230. * 150. TRANS 9.0 * 28. • 11. IVER 28. 160. « 120. Table 1: Timing results of APL benchmark details on this and tables 2 thru 4, see the Benchmarks" text box on page 204. programs. For 'Notes on APL 196 April 1981 © BYTE Publications Inc H & E CQMPJTRQNICS N EVERYTHING FOR YOUR TRS-80* • ATARI* • APPLE* • PET* • •TRS-60 is a trademark of the Radio Shack Division of Tandy Corp. - 'ATARI is a trademark of Atari Inc. - 'Apple is a trademark of Apple Corp. - *Pet is a trademark of Commodore BUSINESS PAC 100 100 Ready-To-Run Business Programs * 30-Day money °« Software (ON CASSETTE OR DISKETTE) Includes 110 Page Users Manual 5 Cassettes (Or Diskettes) Inventory Control Payroll Bookkeeping System Stock Calculations Checkbook Maintenance.... .Accounts Receivable.. ...Accounts Payable BUSINESS 100 PROGRAM LIST 1 RCILE78 2 ANNU1 3 DATE 4 DAYYEAR 5 LEASE1NT 6 BREAKEVN 7 DEPRSL 8 DEPRSY 9 DEPRDB 10 DEPRDDB 11 TAXDEP 12 CHECK2 13 CHECKBK1 14 MORTGAGE/A 15 MtlLTMON 16 SALVAGE 17 RRVARJN 18 RRCONST 19 EFFECT 20 FVAL 21 PVAL 22 LOANPAY 23 REGWTTH 24 S1MPDISK 25 DATEVAL 26 ANNUDEF 27 MARKUP 28 SINKFUND 29 BONDVAL 30 DEPLETE 31 BLACKSH 32 STOCVAL1 33 WARVAL 34 BONDVAL2 35 EPSEST 36 BETAALPH 37 SHARPE1 38 OPTWRrTE 39 RTVAL 40 EXPVAL 41 BAYES 42 VALPRINF 43 VALADINF 44 UTILITY 45 SIMPLEX 46 TRAMS 47 EOQ 48 QCIEUEl 49 CVP 50 CONDPROF 51 OPTLOSS 52 FQUOQ NAME 53 FQEOWSH 54 FQEOQPB 55 QC1ECJECB 56 NCFANAL 57 PROFIND 58 CAP1 Circle 133 on inquiry card. Interest Apportionment by Rule of the 78's Annuity computation program Time between dates Day of year a particular date falls on Interest rate on lease Breakeven analysis Straightline depreciation Sum of the digits depreciation Declining balance depreciation Double declining balance depreciation Cash flow vs. depreciation tables Prints NEBS checks along with dairy register Checkbook maintenance program Mortgage amortization table Computes time needed for money to double, triple. Determines salvage value of an investment Rate of return on investment with variable inflows Rate of return on investment with constant inflows Effective interest rate of a loan Future value of an investment (compound interest) Present value of a future amount Amount of payment on a loan Equal withdrawals from investment to leave over Simple discount analysis Equivalent & nonequivalent dated values for oblig. Present value of deferred annuities % Markup analysis for items Sinking fund amortization program Value of a bond Depletion analysis Black Scholes options analysis Expected return on stock via discounts dividends Value of a warrant Value of a bond Estimate of future earnings per share for company Computes alpha and beta variables for stock Portfolio selection model-i.e. what stocks to hold Option writing computations Value of a right Expected value analysis Bayesian decisions Value of perfect information Value of additional information Derives utility function Linear programming solution by simplex method Transportation method for linear programming Economic order quantity inventory model Single server queueing (waiting line) model Cost-volume-profit analysis Conditional profit tables Opportunity loss tables Fixed quantity economic order quantity model DESCRIPTION As above but with shortages permitted As above but with quantity price breaks Cost-benefit waiting line analysis Net cashflow analysis for simple investment Profitability index of a project Cap. Asset Pr. Model analysis of project 59 WACC Weighted average cost of capital 60 COMPBAL True rate on loan with compensating bal. required 61 DISCBAL True rate on discounted loan 62 MERGANAL Merger analysis computations 63 FINRAT Financial ratios for a firm 64 NPV Net present value of project 65 PRINDLAS Laspeyres price index 66 PR1NDPA Paasche price index 67 SEASIND Constructs seasonal quantity indices for company 68 T1METR Time series analysis linear trend 69 T1MEMOV Time series analysis moving average trend 70 FUPR1NF Future price estimation with inflation 71 MAILPAC Mailing list system 72 LETWRT Letter writing system-links with MAILPAC 73 SORT3 Sorts list of names 74 LABEL I Shipping label maker 75 LABEL2 Name label maker 76 BCJSBCJD DOME business bookkeeping system 77 TTMECLCK Computes weeks total hours from fimeclock info. 78 ACCTPAY In memory accounts payable system-storage permitted 79 INVOICE Generate invoice on screen and print on printer 80 INVENT2 In memory inventory control system 81 TELDIR Computerized telephone directory 82 TIMUSAN Time use analysis 83 ASSIGN Use of assignment algorithm for optimal job assign. 84 ACCTREC In memory accounts receivable system-storage ok 85 TERMSPAY Compares 3 methods of repayment of loans 86 PAYNET Computes gross pay required for given net 87 SELLPR Computes selling price for given after tax amount 88 ARBCOMP Arbitrage computations 89 DEPRSF Sinking fund depreciation 90 (JPSZONE Finds GPS zones from zip code 91 ENVELOPE Types envelope including return address 92 ACJTOEXP Automobile expense analysis 93 INSF1LE Insurance policy file 94 PAYROLL2 In memory payroll system 95 DILANAL Dilution analysis 96 LOANAFFD Loan amount a borrower can afford 97 RENTPRCH Purchase price for rental property 98 SALELEAS Sale-leaseback analysis 99 RRCONVBD Investors rate of return on convertable bond 1 00 PORTVAL9 Stock market portfolio storage-valuation program D CASSETTE VERSION D DISKETTE VERSION $99.95 $99.95 NEW -- ofio T E fi u ;r: eE □ TRS-80* MODEL D VERSION $149.95 (Outside ^'Nfi ADD $3.00 FOR SHIPPING IN UPS AREAS (80f)\ A *> ' STAT E) ADD $4.00 FOR C.O.D. OR NON-UPS AREAS ' W / ^37-PjJf O ADD $5.00 OUTSIDE U.S.A. CANADA & MEXICO ■cqmplJtrqnicS": rvVlTV-evWTClAL AP(\JCATONS B£«\^C£ " SO N. PASCACK ROAD SPRING VALLEY, NEW YORK 10977 , HOUR OA ORDER £S* i IMF LINE $P\ ( 914)425-1535 Scalar Dyadic Operators, Softronics APL s < COMMENTS ADD SUBTRACT E MULTIPLY DIVIDE EXPONENT LOGARITHM FLOOR CEILING Dyadic version innaccurate in last decimal place; see text. a: o H < cr L±J 0- O LU s < z o Q < Z o S O o < > a 1 RESIDUE 1 1 FACTORIAL o CIRCLE < < > > LESS THAN, ETC. = * EQUAL TO, NOT EQUAL TO AV AND, OR AV NAND, NOR COMMENTS Gamma function missing. Only sin, cos, tan, arctan im- plemented. Nondyadic Scalar and Mixed Operators, Softronics APL ~ NOT ? ROLL i IOTA (INDEX) p RHO (RESHAPE) • RAVEL XT DECODE, ENCODE H TAKE, DROP f MEMBERSHIP H GRADE-UP GRADE-DOWN s MATRIX DIVIDE OR INVERSE COMMENTS Dyadic available as defined function only. Catenation for vectors only; no lamination. Available as defined function only. Both available as defined func- tion only. tr LU a. o UJ < Z < z o S a < >~ Q s TRANSPOSE (D ROTATE OR REVERSE e ROTATE / COMPRESS i COMPRESS \ EXPAND \ EXPAND <}> EXECUTE ? FORMAT COMMENTS Dyadic "diagonal" transpose missing. Dyadic function available for vectors and two-dimensional matrices only available as defined function. Available as /[1] only. Converts a vector or array to a character string (with embedded carriage return) for printing. Composite Operators, Softronics APL IE O 1- < a: UJ m < HI SE < O- < > o z < •/ REDUCTION fr REDUCTION -I to < 3 > < fg INNER PRODUCT OUTER PRODUCT [7] Notes: "Y" and "N" mean that a given operator is either present in all its forms or totally absent from this verion of APL. "Y*" means that the operator is only partially present in this version. "N*" means that the operator is not present in this version but that part or all of it is avail- able through an APL defined function supplied with this version. Further information explaining "Y*" and "N*" is given in the "Comments" column. A scalar is an object (number or character) with no dimension. A vector is a string of objects that have one dimension. An array is a matrix of objects that have two or more dimensions. Other features: standard APL commands, system functions, and system variables; line editing only of defined functions; PEEK and POKE functions; 8080-type port IN and OUT functions; shared variable mechanism for interaction with disk files (sequential read and write only, in standard CP/M format); mixing of APL data structures (arrays, vectors, scalars) in records of same file; user choice of standard terminal, APL terminal, or video board with programmable character generator; and good documentation. Other limitations: several much-needed operators are missing (see body of this table) and there is no random access to disk files' char- acter-editing of defined functions. Table 2: Summary of Softronics APL features. 198 April 1981 © BYTE Publications Inc E CQMPUTRQMCS N • • EVERYTHING FOR YOUR TRS-80™ • • MODEL III * All orders processed within 24-Hours * 30-Day money back guarantee on all TRSDOS Software • Add $2.00 for shipping in UPS Areas • Add $4.00 for COD. or NON-UPS Areas * Add $5.00 outside U.S.A., Canada & Mexico •k We will match any bonafide advertised price in any of the Major Computer Magazines TUS-Mh l trademark ol Tandy Com. ) GENERAL LEDGER, ACCOUNT8 RECEIVABLE, ACCOUNT8 PAYABLE, PAYROLL, INVENTORY CONTROL AND INVOICING (Small Business Group) an extensive business system for the serious user can be used one module at a time or as a coordinated system $198.95 per module $1199.95 for the complete system.* !) MASTER PAC 100 100 essential programs BUSINESS PERSONAL FINANCE STATISTICS MATH GAMBLING GAMES includes 125 page manual and 5 diskettes $59.95 i) BUSINESS PAC 100 100 essential business programs INVENTORY CONTROL PAY- ROLL BOOKKEEPING SYSTEM STOCK CALCULATIONS CHECKBOOK MAINTEN- ANCE ACCOUNTS RECEIVABLE ACCOUNTS PAYABLE includes 125 page manual and five diskettes $99.95 l) INFORMATION SYSTEM (The Bottom Shelf) An in-memory information system for small mailing lists, inventories (i.e. books, articles, records, program reference files) Can be used for anything that you would use rolodex or index card files Up to ten user define fields Programmable printouts for rolodex cards, mailing labels, etc Will identify all records that contain a group of characters you've entered even if that group is in the middle of a line Sorts data base by any field $49.50* I) DATA MANAGER II (The Bottom Shelf) RANDOM ACCESS Disk based DATA MANAGE- MENT SYSTEM (Similiar to INFORMATION SYSTEM above but RANDOM ACCESS STORAGE expands the amount of storage space available) Used to replace index cards for medium sized mail lists, inventories, personnel records, sates prospects, etc Uses up to four disk drives on line Up to twenty user defined fields, programmable printouts for rolodex cards, etc will identify all records that contain a group of characters you've entered even if that group is in the middle of a line maintain up to 5 changeable presorted "key" files variable length random records (the smaller the record you define, the more records yu can store) $99.95* i) BUSINESS MAIL SYSTEM (The Bottom Shelf) Handles large mailing lists (up to 150.000 names) supports 3 or 4 line addresses files automatically in zip code order, alphabetical within zip code formats for 1 to 4 across mailing labels supports quick disk location of single or multiple names meets all industry and postal standards numeric code fields included for printing selected records $125.00* ') ANALYSIS PAD (The Bottom Shelf) A Columnar Calculator for financial analysis, line item budgeting, cost analysis, sales analysis and almost any financial function (and many statistical functions) create matrixes of 29 * 39 make all entries at one time either by row or column add. delete, move or switch columns and rows edit any data from full screen display add. subtract, multiply and divide one column by another and put results in designated column (up to six calculations can be made and placed in designated column) define columns as con- stants save calculations and formulas on disk results can be printed in a variety of report formats $99.95* i) CHECKBOOK II (The Bottom Shelf) A complete in memory checkbook balancing and reconcilliation program five column keyboard input with 5 characters for check number. 16 for payee. 4 for code numerical sort routine $49.50* I) CHECK REGISTER ACCOUNTING SYSTEM (The Bottom Shelf) A complete random access checkbook system set and define up to 60 accounts with as many income accounts as you choose complete checkbook balancing and reconcilliation single entry input where transaction can be dispersed over several accounts enables user to make a 64-character note on each transaction printout your own check after data entry prints monthly summaries of each account with month and year-to-date totals create a suspense file to remind you of coming expenses Reports generated included Check Register (for any month), notes to Check Register, Income/Expense Distribution Report. Statement of Selected Accounts. Bank Reconcile Statement, Suspense File and Full Account Distribution Statement $74.95* l) LIBRARY 100 (The Bottom Shelf) 100 Programs on a broad range of topics Finance Education Graphics Home Games CASSETTE VERSION $49.50 DISK VERSION $74.95 ) ADVENTURE (by Scott Adams) A series of games (for ages 10-99) wander through en- chanted worlds seeking treasures 1. Adventureland 2. Pirate's Adventure 3. Mission Impossible Adventure 4. Voodoo Castle 5. The Count 6. Strange Odyssey 7. Mystery Fun House 8. Pyramid of Doom 9. Ghost Town (#1 and #2 recommended for the movie adventure) Each adventure $14.95 (jon cassette) Diskette versions sold in groups of three at $39.95 per three programs (#1 - #3. #4 - #6, #7 - #9). I) HORSE SELECTOR II (Dr. Hal Davis) New simplified version of the original Horse Selector (for flats) The first Horse Selection System to actually calculate the estimated offs for each horse easy to follow rules uses 4 factors (speed rating, track variant, distance of the present race, distance of the last race) calculated estimated odds FREE DUTCHING TABLES allows betting on 2 or more horses with a guaranteed profit $50.00 I) MON-3 and MON-4 (Howe Software) Powerful utility programs enabling you to interact directly with your TRS-80 in MACHINE LANGUAGE The monitor comes with complete 40-page instruction manual making it useful for both the beginner and advanced programmer.... simple commands make it easy to use functions include DISPLAY, DISASSEMBLE, MOVE and COMPARE, SEARCH. MODIFY, RELOCATE. PRINT, READ and WRITE. UNLOAD, SAVE and READ, INPUT and OUTPUT, SEND and RECEIVE MON-3 $39.95 (for cassette) MON-4 $49.95 (for disk). (14) SMART TERMINAL (Howe Software) enables your TRS-80 to be used as a remote terminal to a time sharing computer system $69.95 (15) FA8T 80RT (Howe Software) a series of machine-language subroutines to sort data from BASIC programs data may be alphabetic (string) or numeric easily interfaced with your BASIC programs (no machine language knowledge is necessary) $9.95 (16) MAILING LIST (Howe Software) maintains mailing lists of over 1000 names commands allow adding, changing, deleting, and finding names. Sorting is done in machine language subroutine labels printed in 1, 2 or 3 columns $69.95 (17) HOME BUDGET (Howa Software) combines the maintenance of your checkbook with analysis of your income, expenses and monthly bills. Handles data including bills, income, deposits, checks and debits to your checking account, and cash expenses. Computes check- book balance, list of unpaid bills, monthly and year-to-date summaries of income and expenses showing income tax deductions All output printed on video display or line printer comes with complete instructions manual $49.95* (16) SMALL BUSINESS ACCOUNTING (Howe Software) Based on the DOME BOOKKEEPING SYSTEM keeps track of all income, expenditures and payroll for a small business of up to 16 employees income and expenditures can be entered on a daily, weekly or monthly basis computes monthly and year to date totals manual contains complete instructions for custom- ization Cassette version $29.95 Diskette version $49.95 (19) REMODEL-PROLOAD (Racet Computes) Renumber program lines move statements from one part of a program to another $34.95 (20) GSF (Racet Computes) Lightning fast in-memory machine language sort utility that can be made part of your BASIC progams without any machine language knowledge includes several other utilities to speed up your BASIC programs no machine knowledge necessary to use GSF in your BASIC programs $30.00 (21) DOSORT (Racet Computes) includes GSF (above) extends the in memory sort to sorts on multiple disk drives $45.00* (22) COPSYS (Racet Computes) allows the user to make copies of machines language cassettes without any knowledge of machine language $20.00 (23) COMRPOC (Racet Computes) an auto load program for disk users allows the user to insert a diskette into their MOD-HI and have the computer take over all loading load a machine language program, BASIC, RUN a certain program all without pressing a single button allows your computer to perform 10. 20. 30 or more functions without pressing a single button $30.00* (24) INFINE BASIC (Racet Computes) adds a variety of machine language subroutines to your BASIC programs (without any machine language knowledge) fast sorts matrix operations compress and uncompress data and more $60.00 (25) INFINITE BUSINESS (Racet Computes) an add on package to INFINITE BASIC adds a variety of routines important to the businessman (increase accuracy of calculations and more) $30.00 (26) DMS (Racet Computes) lightning fast machine language sort sorts up to 4 disk drives of information $90.00* (27) BLINK (Racet Computes) allows you to RUN new programs without losing the variables stored in your previous program line many programs together without losing important variables $30.00* (28) KFS-80 (Racet Computes) now you can use ISAM (Index Sequential Access Files) on your MOD-MI using ISAM in your BASIC programs allows instant access of your items in your data files use with mail programs inventory programs etc. $100.00* (29) MAIL LIST (Racet Computes) all routines are in machine language allowing for quick access $75.00 • for disk only Circle 134 on Inquiry card. •CQMPLITRQNICS: NAATV«\AAT CAl APRXAIOfc b* t*yt 1 50 N. PASCACK ROAD SPRING VALLEY, NEW YORK 10977 NEW TOLL-FREE ORDER LINE (OUTSIDE OF NY. STATE) (800) 431-2818 HOUR ORDER LINE (914) 425-1535 Scalar Dyadic Operators, Ramware APL80 + ADD m h - SUBTRACT X MULTIPLY E * DIVIDE * EXPONENT ® LOGARITHM L FLOOR r CEILING h 0- o < o 2 >- Q COMMENTS 1 RESIDUE 1 FACTORIAL Gamma function missing. o CIRCLE Hyperbolic and hyperbolic inverse not defined. < < > > LESS THAN, ETC. = * EQUAL TO, NOT EQUAL TO AV AV AND, OR NAND, NOR Assumes nonzero values are equivalent to 1 or true (non- standard). H i H a Nondyadic Scalar and Mixed Operators, Ramware APL80 1 5 NOT (T) ? ROLL 0] [T] i IOTA (INDEX) 0| 0| p RHO (RESHAPE) [7] W\ RAVEL \T\ [7T] IT DECODE, ENCODE 0j TAKE, DROP (Tj MEMBERSHIP |Tj COMMENTS Catenation for arrays, vectors, along last coordinate only; no lamination. Right argument of encode limited to scalars only. grade-up nr\ GRADE-DOWN LU MATRIX DIVIDE OR INVERSE o Q / / \ \ ¥ COMMENTS transpose (yTI [771 Monadic transpose is nonstan- L - 11 — ' dard for 3-dimensional or larger ROTATE OR REVERSE ROTATE COMPRESS COMPRESS EXPAND EXPAND EXECUTE FORMAT Sr—n arrays; dyadic "diagonal' I— I transpose missing. [n*] Available as (A [1] only. Available as / [1] only. Available as \ [1]. Fl Sets field width and number of decimal places for future output. Composite Operators, Ramware APL80 o f/ REDUCTION (■/■ REDUCTION < COMMENTS < Available as f/[1] fg INNER PRODUCT OUTER PRODUCT CO < > Notes: "Y" and "N" mean that a given operator is either present in all its forms or totally absent from this version of APL. "Y*" means that the operator is only partially present in this version. "N*" means that the operator is not present in this version but that part or all of it is avail- able through an APL defined function supplied with this version. Further information explaining "Y*" and "N*" is given in fhe "Comments" column. A scalar is an object (number or character) with no dimension. A vector is a string of objects that have one dimension. An array is an matrix of objects that have two or more dimensions. Other features; five tutorial programs on APL included in package; standard APL commands, automatic execution of latent expression; tracing of function execution; choice of single (6-digit) or double (1 5-digit) precision in output; real-time clock, line and character editing of defined functions; print formatting and system control variables(APL l-bar functions); positioning of screen output (equivalent to PRINT @ in BASIC); use of periods and dashes in variable names; PEEK, POKE, and CALL functions; random or sequential access of file records; up- dating of file records; and mixing of APL data structures (ie: arrays, vectors, scalars) in records of same disk file. Other limitations: only one assignment operator per line; maximum of thirty-two functions per workspace and 255 lines per defined function; arrays limited to sixty-three dimensions; uses one-letter substitutions for APL operators (but these substitutions are differentiated from normal text). Table 3: Summary of Ramware APL80 features. 200 April 1981 © BYTE Publications Inc The Hard Facts About Software I THREADED INTERPRETIVE LANGUAGES 9 by Ronald Loeliger Threaded languages (such as FORTH) are compact, giving the speed of assembly language with the programming ease of BASIC. They combine features found in no other pro- gramming languages. This book develops an interactive, extensible language with specific! routines for the Zilog Z80 microprocessor. With the core interpreter, assembler, and i * data type defining words covered in the text, it is possible to design and implement programs for almost any application and equivalent routines for different processors. £ Threaded Interpretive + ADD m E - SUBTRACT s X MULTIPLY m * DIVIDE e • EXPONENT h ® LOGARITHM L FLOOR r CEILING < a. I o < < > > = * AV AV RESIDUE COMMENTS factorial (Tj Gamma available as a defined function. circle FTI (yTI Hyperbolic, inverse yjQ 2 - 1 , LESS THAN, ETC. EQUAL TO, NOT EQUAL TO AND, OR NAND, NOR VB=n not defined. Nondyadic Scalar and Mixed Operators, Vanguard APL Q. O < z O S >- Q ~ NOT ? ROLL I IOTA (INDEX) P RHO (RESHAPE) • RAVEL XT DECODE , ENCODE u TAKE, DROP i MEMBERSHIP H GRADE-UP GRADE-DOWN B MATRIX DIVIDE OR INVERSE COMMENTS Catenation for arrays, vectors, along all coordinates; lamination available as defined function. Right argument of encode limited to scalars only. Both available as defined func- tion only. o s (D / t \ \ & ? TRANSPOSE ROTATE OR REVERSE ROTATE COMPRESS COMPRESS EXPAND EXPAND EXECUTE FORMAT COMMENTS Monadic transpose for arrays available as defined function only. Both forms work for vectors only; for all arrays, available as defined functions only. Available as / [1] only. Available as \ [1] only. Left argument is print width and |T| number of decimal places; right argument is vector or array to be formatted. a. o l- < UJ n. hi _i to < -I LU Q. O S < z < 5 COMMENTS '/ REDUCTION .r REDUCTION Available as f / [1] only. Composite Operators, Vanguard APL p 3 < < £ uj -l uj S < Q- < > O Z < f.g INNER PRODUCT o.f OUTER PRODUCT [7| Notes: "Y"and "N" mean that a given operator is either present in all its forms or totally absent from this version of APL. "Y*" means that the operator is only partially present in this version. "N*" means that the operator is not present in this version but that part or all of it is avail- able through an APL defined function supplied with this version. Further information explaining "Y*" and "N*" is given in the "Comments" column. A scalar is an object (number or character) with no dimension. A vector is a string of objects that have one dimension. An array is a matrix of objects that have two or more dimensions. Other features: standard APL commands, system functions, and system variables; line editing only of defined functions; shared variable mechanism for interaction with disk files (sequential and random access); mixing of APL data structures (arrays, vectors, scalars) in records of same disk file; the ability to share with any Z80 I/O port. Other limitations: only way to use this software with a non-APL terminal or video board uses one-letter substitutions of a standard ASCII character for APL operators (plus these substitutions are not differentiated from normal text); documentation is adequate but terse; no character editing of defined functions. Table 4: Summary of Vanguard APL/DTC software features. 202 April 1981 © BYTE Publications Inc "WITH THE UCSD p-SYSTEM; WE CAN WRITE ONE APPLICATION THAT GOES FROM APPLE TO ZENITH!' HARRY BLAKESLEE, President, Denver Software UCSD p-System and UCSD Pascal are trademarks of the Regents of the University of California. Our business is bigger and better than ever. A lot of the credit for that goes to the UCSD p-System software from SofTech Microsystems. It's given us ten times the market we used to have. We can write a single, sophisticated applications program with the UCSD p-System— like our financial management package— and it just keeps on running. On Apple, Commodore, Ohio Scientific, Texas Instruments, Zenith, and more. That's the real beauty of the UCSD p-System. Any program you write for one microcomputer runs on others, both today and tomorrow. You protect your software investment, without restricting your hardware options. And with the UCSD p-System,you can use the language of your choice -UCSD Pascal,™ FORTRAN-77, BASIC, or assembly language. All are backed by SofTech Microsystems, a leading system software company who's been around for over a decade, who knows how to develop professional quality software, and who's committed to delivering it. Get a head start on tomor- row. With the microcomputer software that goes from "A" to "Z." Distribution licensing and single copies available. Write or call for details, so you can start going places, too. micposvsTems (=» 5USSIDIRHV OF SOFTECH For the software that's going places. 9494 Black Mountain Road, San Diego, CA 92126. (714)578-6105 TWX: 910-335-1594 Circle 136 on inquiry card. BYTE April 1981 203 Notes on APL The following information specifies the tests that are run on all versions of APL that are examined at BYTE magazine. Defined function SETUP, shown in listing 1, creates the APL variables that will be used in the tests shown in table 1. A and B are 10 by 10 matrices used in tests like A + B to perform an opera- tion 100 times with one statement. C is a ten-element vector giving the values from it to 10ir. D is a 10 by 10 matrix of trigonometric values. E is a ten-element vec- tor of the values from 1 to 10 (used to test the outer product operator). F is a vector used to convert sec- onds to years, days, hours, minutes, and seconds in the test F T 100000000, using the encode (i) operator. RA and RB are 100-element vectors made from the elements of matrices A and B. Finally, M3D is a three- dimensional array used to test rotation around a non- default axis. The function TIME in listing 2 was used in timing the performance of a function. Statements 20 thru 60 are performed N times, with the (exp) in each line replaced by the function being tested (for example, Q—A-r-B). Statement 80 displays the total number of times the function has been performed, while state- ment 90 requests the number of seconds used in the test (timed by a stopwatch) and displays the time used to perform the function once. Each function is per- Benchmarks formed five times within TIME to maximize the time spent executing the function when compared to the time spent executing statement 10 and repeatedly executing line 70 N times. In addition, the TIME func- tion was performed with increasing values of N until the unit time agreed to three significant places. The timing values in table 1 are rounded to two significant places. Three short APL functions, CIRCLE, TRANS, and IVER, are used as benchmarks to grade the perfor- mance of an APL implementation in less abstract terms. (See listings 3, 4, and 5.) CIRCLE takes a numeric matrix and adds a set value to all matrix elements in an imaginary circle with a given center and radius. (This function was used to set up a "picture" matrix of geometric shapes in a pattern-recognition algorithm.) The TRANS function transforms a matrix of numbers into a matrix of symbols, with the in- dividual symbols used to reflect the value of the cor- responding numeric matrix entry. The IVER function was presented by Dr Kenneth Iverson in the article "Understanding APL" (August 1977 BYTE, page 36). When given a right argument of seven or larger, it returns a vector containing all the prime numbers up to and including that number. (For example, IVER 11 returns the vector 2 3 5 7 11.) Notes: • All of the above tests are performed on either 10 by 10 matrices or 100-element vectors; in addition, the tests were carried out to minimize the amount of time outside the operation being timed. • In some cases, a version of APL could not operate on a given size matrix. An asterisk denotes an estimated entry made by adjusting the time an opera- tion took for a smaller matrix. • CIRCLE, TRANS, and IVER (shown in listings 3 thru 5) are APL defined functions used to compare the versions of APL in a working environment. • All numbers here are given to 2 significant digits. • In the cases where a version of APL gives the user an APL defined function (a short program written in APL) to use when the operation is not in the machine- code version of APL, the defined function is used in the above timing tests. For example, none of the above versions of APL incorporate matrix divide in their ver- sions, but Softronics and Vanguard supply an APL defined function to do the same operation. • NA means the function is not available in a given version of APL. • The Ramware APL80 was run on an unmodified Radio Shack TRS-80 Model I with one disk drive and 48 K bytes of memory. The TRS-80 runs at 1 MHz; all timing figures should be halved for users running modified TRSSOs at 2 MHz. • The Softronics APL was run on a Cromemco Z2D with 56 K bytes of memory, running at 4 MHz. • The Vanguard APL/DTC software was run on an APL/DTC computer with 80 K bytes of memory, run- ning at 4 MHz. Users buying the Vanguard APL/V80 software should expect slightly decreased performance varying with the amount of memory in the system. Text continued from page 196: be devised. APL operators that normally do not appear on the keyboard have a 1-character substitution. For ex- ample, the character % replaces the APL division operator +, and parentheses () replace the square brackets [] used in APL to denote subscripts. Other characters are represented by a shifted keyboard letter; for example, shift-q is used for the APL character □ (a quad), and shift-i is used for the APL iota operator t. On the TRS-80 video screen, these characters are displayed as their uppercase alphabetic equivalents (because an un- modified TRS-80 has no lowercase letters) with a little graphic dot just below and to the left of the uppercase let- ter. This, plus one space on the left of the single letter substitution, makes this system more readable. (See photo 1 for the APL80 equivalent of the CIRCLE function of listing 3a). Many other Level Il-related features make Ramware APL80 a usable product and certainly the best buy dollar-for-dollar. Several other features that must be mentioned are sequential and random access of APL disk files and access to the real-time clock; other features are listed in table 3. Vanguard APL/DTC Computer and Software Two of the 'At a Glance" boxes describe the last ver- 204 April 1981 © BYTE Publications Inc circle 737 'nquiry card. Ste-Julie. Quebec Canada JOL 250 (514)649-6185 BYTE April 1981 205 The ZVX4 MEGABYTER is for the APPLE II user who wants to DOUBLE file size, expand the capability of existing business software, and make other SERIOUS applications more viable. Now you can have compatibility with IBM, INTEL, CP/M*, Z80 Softcard*, UCSD Pascal, and others. Look what the MEGABYTER dual density 8" floppy disk controller, with its LSI circuitry and reliable industry standard IBM 3740 format, means to you: INCREASED STORAGE • Increase online storage to 2 Mega bytes • Double your maximum accounts and file size • Add high capacity efficient hard disk backup • Control up to 4 Shugart SA800/SA850 drives IMPROVED COMPATIBILITY • Operate APPLE DOS 3.1/3.2/3.3, mini disks • Preserve existing software investment • Interchange data with other computers SIMPLIFIED OPERATION • Reduce disk handling and I/O slot usage • Gain automatic single/double density operation • Change to double sided drives with one switch Available at your Apple dealer. Call or write today! ^-\ \ S >sva>; L^ _/ {-, SORRENTO VALLEY ASSOCIATES 1722 SORRENTO VALLEY ROAD SAN DIEGO, CA 92121 (714) 452-0101 * CP/M trademark of Digital Research, Inc. Z80 Softcard trademark of Microsoft, Inc. 1 V e 9 7* COT/UBS "W •"■ a 09 ,iam ' V(UIE «Q '£«« 3 4 9KIROE A MK TO T>£ AKAY ft C1RCU *CWiC «* MHOS 4.UITH (XHTDt AT ( t, 5) • 9 V n * * SOI «# ( 1) JR C 3H 1 HDCTROH :«M «WM ♦ 1 ML I (HI) JML HI (RfJI ICO. )4« ( 4) IS DIP "OX «■ ( {MA ( 3)MKTCa Mi IS +( fcftXTRCU )( HOI OK ( 1H« ( 3» 1 Photo Is The APL function CIRCLE as presented by Ramware APL80. In this version of APL for the TRS-80 Model I, nonstan- dard APL characters are replaced by either a 1-character substitution or by a single letter marked by a graphics dot below and to the left of the letter. Photo 2: The Vanguard Systems Corporation APL/DTC. The system includes: the APL/DTC (desk-top) computer, on the left; its associated APL terminal, on the right; and, on top of the computer, documentation and two floppy disks of soft- ware — customized CP/M and Vanguard APL. sion of APL, which was reviewed as a computer/soft- ware combination called APL/DTC. The computer and software have been optimized for each other, creating a version of APL that is slightly more powerful than its stand-alone software counterpart, APL/V80. The APL/DTC system, which carries a label of the same name (see photo 2), is actually a Vector Graphics microcomputer with modifications made at Vanguard Systems Corp. (One modification results in the computer holding 80 K bytes of memory.) Its associated terminal, which displays all APL characters (as shown in photo 3) has an APL keyboard and is a Vector Graphics "Mindless Terminal" (a keyboard and video display that connects to a memory-mapped video board inside the computer proper). Its associated video board has a PROM (pro- grammable read-only memory device) that generates the APL character set. The APL/DTC computer runs CP/M as customized by Lifeboat Associates and Vanguard. The 206 April 1981 © BYTE Publications Inc Circle 138 on inquiry card. Start learning and computing for only $129.95 with a Netronics 8085-based computer kit. Then expand it in low-cost steps to a business/development system with 64k or more RAM, 8" floppy disk drives, hard disks and multi- terminal I/O. THE NEW EXPLORER/85 SYSTEM Special! Full 8" floppy, 64k system for less than the price of a mini! Only $1499.95! (Also available wired & tested. $1799.95) Imagine — for only $129.95 you can own the starting level of Explorer/85, a computer that's expandable into full business/development capabilities — a computer that can be your beginner system, an OEM controller, or an IBM-formatted 8" disk small business system. From the first day you own Explorer/85, you begin computing on a significant level, and applying princi- ples discussed in leading computer magazines. Ex- plorer/85 features the advanced Intel 8085 cpu, which is 100% compatible with the older 8080A. It offers on- board S-100 bus expansion. Microsoft BASIC in ROM, plus instant conversion to mass storage disk memory with standard IBM-formatted 8" disks. All for only $129.95, plus the cost of power supply, keyboard/ terminal and RF modulator if you don't have them (see our remarkable prices below for these and other, ac- cessories). With a Hex Keypad/display front panel. Level "A" can be programmed with no need for a ter- minal, ideal for a controller, OEM, or a real low-cost start. Level "A" is a complete operating system, perfect for [beginners, hobbyists, industrial controller use. $129.95 LEVEL "A" SPECIFICATIONS Explorer/85's Level "A" system features the advanced Intel 8085 cpu, an 8355 ROM with 2k deluxe monitor/ operating system, and an advanced 8155 RAM I/O . . . all on a single motherboard with room for RAM/ROM/ PROM/EPROM and S-100 expansion, plus generous prototyping space. PC Board: Glass epoxy, plated through holes with solder mask. • I/O: Provisions for 25-pin (DB25) con- nector for terminal serial I/O, which can also support a paper tape reader . . . cassette tape recorder input and output . . . cassette tape control output . . . LED output indicator on SOD (serial output) line . . . printer inter- face (less drivers) . . . total of four 8-bit plus one 6-bit I/O ports. • Crystal Frequency: 6.144 MHz. • Control Switches: Reset and user (RST 7.5) interrupt . . . addi- tional provisions for RST 5.5, 6.5 and TRAP interrupts onboard. • Counter/Timer Programmable, 14-bit bi- nary. • System RAM: 256 bytes located at F800, ideal for smaller systems and for use as an isolated stack area in expanded systems . . . RAM expandable to 64K via S-100 bus or 4k on motherboard. System Monitor (Terminal Version): 2k bytes of deluxe system monitor ROM located at F000, leaving 0000 free for user RAM/ ROM. Features include tape load with labeling . . . examine/change contents of memory . . . insert data . . . warm start . . . examine and change all registers . . . single step with register display at each break point, a debugging/training feature ... go to execution address . . . move blocks of memory from one location to another . . . fill blocks of memory with a constant . . , display blocks of memory . . . automatic baud rale selection to 9600 baud . . . variable display line length control (1-255 characters/line) . . . chan- nelized I/O monitor routine with 8-bit parallel output for high-speed printer . . . serial console in and console out channel so that monitor can communicate with I/O ports. System Monitor (Hex Keypad/Display Version): Tape load with labeling . . . tape dump with labeling . . . examine/change contents of memory . . . insert data . . . warm start . . . examine and change all registers . . . Full 8" disk system for less than the price of a mini (shown with Netronics Explorer/85 computer and new terminal). System features floppy drive from Control Data Corp., world's largest maker of memory storage systems ( not a hobby brand/,) Level "A" With Hex Keypad/Display. single step with register display at each break point . . . go to execution address. Level 'A" in this version makes a perfect controller for industrial applications, and is programmed using the Netronics Hex Keypad/ Display. It is low cost, perfect for beginners. HEX KEYPAD/DISPLAY SPECIFICATIONS Calculator type keypad with 24 system-r'efined and 16 user-defined keys. Six digit calculator-type display, that displays full address plus data as well as register and status information. LEVEL "B" SPECIFICATIONS Level "B" provides the S-100 signals plus buffers/ drivers to support up to six S-100 bus boards, and in- cludes: address decoding for onboard 4k RAM expan- sion selectable in 4k blocks . . . address decoding for onboard 8k EPROM expansion selectable in 8k blocks . . . address and data bus drivers for onboard expansion . . , wait stalegenerator(jumperselectable). to allow the use of slower memories . . . two separate 5 volt regula- tors. LEVEL "C" SPECIFICATIONS Level "C" expands Explorer/85's motherboard with a card cage, allowing you to plug up to six S-100 cards directly into the motherboard. Both cage and card are neatly contained inside Explorer's deluxe steel cabinet. Level "C" includes a sheet metal superstruc- ture, a 5-card. gold plated S-100 extension PC board thai plugs into the motherboard, number of S-100 connectors. Just add required LEVEL "D" SPECIFICATIONS Level "D" provides 4k of RAM, power supply regula- tion, filtering decoupling components and sockets to expand your Explorer/B5 memory to 4k (plus the origi- nal 256 bytes located in the 8155A). The static RAM can be located anywhere from f&ffl to EFFF in 4k blocks. LEVEL "E" SPECIFICATIONS Level "E" adds sockets for 8k of EPROM to use the popular Intel 2716 or the TI 2516. It includes all sockets, power supply regulator, heat sink, filtering and decou- pling components. Sockets may also be used for 2k x 8 RAM IC's (allowing for up lo 12k of onboard RAM). DISK DRIVE SPECIFICATIONS • 8" CONTROL DATA CORP. • Data capacity: 401.016 bytes professional drive. (SD). 802,032 bytes (DD). • LSI controller. unformatted. • Write protect. • Access time: 25ms (one • Singleordoubledensity. track). DISK CONTROLLER/ I/O BOARD SPECIFICATIONS • Cont. , olsuptofour8"drives. • 1771A LSI (SD) floppy disk conl roller. • Onboard data separator (IBM compatible). • 2 Serial I/O ports • Autoboot lo disk system when system reset. • 2716 PROM socket included for use in custom applications. • Onboard crystal controlled. • Onboard I/O baud rate generators to 9600 baud. • Double-sided PC board (glass epoxy.) DISK DRIVE CABINET/POWER SUPPLY • Deluxe steel cabinet with individual power supply for max- imum reliability and stability. ORDER A COORDINATED EXPLORER/85 APPLICATIONS PAR! Beginner's Pak (Save $26.00!)— Buy Level "A" (Ter- minal Version) with Monitor Source Listing and AP-1 5-amp Power Supply: (regular price $199.95), now at SPECIAL PRICE: $160.95 plus post. & insur. Experimenter's Pak II (Save $53.40!) — Buy Level "A" (Hex Keypad/Display Version) with Hex Keypad/Display, Intel 8085 User Manual, Level "A" Hex Monitor Source Listing, and AP-1 5-amp Power Supply: (regular price $279.35), all at SPECIAL PRICE: $219.95 plus post. & insur. Special Microsoft BASIC Pak (Save $103.00!) — In- cludes Level "A" (Terminal Version). Level "B". Level "D" (4k RAM), Level "E ". 8k Microsoft in ROM. Intel 8085 User Manual, Level "A" Monitor Source Listing, and AP-1 5-amp Power Supply: (regu- lar price $439.70), now yours at SPECIAL PRICE: $329,95 plus post. & insur. ADD A TERMINAL WITH CABINET, GET A FREE RF MODULATOR: Save over $114 at this SPECIAL PRICE: $499.95 plus post. & insur. Special 8" Disk Edition Explorer/85 (Save over $104!) — Includes disk-version Level "A". Level "B", two S-100 connectors and brackets, disk controller. 64k RAM, AP-1 5-amp power supply, Explorer/85 deluxe steel cabinet, cabinet fan, 8" SD/DD disk drive from famous CONTROL DATA CORP. (not a hobby brand!), drive cabinet with power supply, and drive cable set-up for two drives. This package includes everything but terminal and printers (see coupon for them). Regular price $1630.30, all yours in kit at SPECIAL PRICE: $1499.95 plus post. & insur. Wired and tested, only $1799,95. Special! Complete Business Software Pak (Save $625.00!) — Includes CP/M 2.0. Microsoft BASIC. General Ledger. Accounts Receivable. Accounts Payable. Payroll Package: (regular price $1325). yours now at SPECIAL PRICE: $699.95. Please send the items checked below: □ F,xplorer/85 Level "A" kit (Terminal Version). . . SI29.95plus $3 post. & insur. □ Explorer/65 Level "A" kit ( Hex Keypad/Display Version) . . . $129.95 plus $3 post. & insur. D 8k Microsoft BASIC on cassette tape. $84.95 postpaid. D 8k Microsoft BASIC In ROM kit (requires Levels "B", "D" and E") . . . $99.95 plus $2 post & insur. □ Level "B" (S-100) kit . . . $49.95 plus $2 post. & insur. D Level "C" (S- 100 (Hard expander) kit $39.95 plus $2 post & insur. Level "D" (4k RAM) kit . . $69.95 plus S2 post. 8. insur. D Level "E" (EPROM/ROM| kit . . . $5.95 plus 50c p&h. □ Deluxe Steel Cabinet for Explorer/B5 . . . $49.95 plus $3 post. & insur. D Fan For Cabinet .. . SI5.00plus $1.50 posl. & insur. D ASCII Keyboard/Computer Terminal kit: features a full 128 character set. u&l case: full cursor control: 75 ohm video output: convertible lo Baudot output: selectable baud rale. RS232C or 20 ma. I/O, 32 or 64 character by 16 line formats, andean be used with either a CRT monitor or a TV sel (if you have an RF modulator) . . . $149.95 plus $3.00 post. & insur. □ DeLuxe Steel Cabinet for ASCII kcyboara/lerminal . . . $19.95 plus $2.50 post. & insur. □ New! terminal/Monitor: (See photo) Same; features as above, except 12" monitor with keyboard and terminal is in deluxe sinfile cabinet; kit . . . $399.95 plus $7 posl. & insur. D Hazelllne terminals: Our prices too low lo quole — CALLUS D Lear-Slgler terminals/printers: Our prices loo low to quote: CALL IS □ Hex Keypad/Display kit $69.95 plus S2 posl. & insur. □ AP-1 Power Supply Kit ±8V ® 5 amps) in deluxe sleel cabinet . . . $39.95 plus S2 post. & insur. □ Gold Plated S-100 Bus Connectors. $4.85 each, postpaid. □ RF Modulator kit (allows you louse your TV set as a monilor) ... $8.95 postpaid. □ 16k RAM kit (S-100 hoard expands lo 64k). . . $199.95 plus $2 posl. & insur. □ 32k RAM kit $299.95 plus $2 posl. 8. insur. □ 48k RAM kit $399.95 plus $2 posl. 8, insur. D 64k RAM kit. . . $499.95 plus $2 post.* insur. □ 16k RAM Expansion kit (lo expand any of Ihe above in 16k hlocks up lo 64k) . . . $09.95 plus $2 posl. & insur. each. r :■ Intel 8083 cpu Users' Manual . . $7.50posipaid. □ 12" Video Monitor (10MHz bandwidth) . . . $139.95 plus $5 posl. & insur. □ Beginner's Pak (see above) $169.95 plus $4 post. & insur. □ Experimenter's Pak (see above) . . . $219.95 plus $6 posl. & insur. D Special Microsoft BASIC Pak Without lermlnal (sra above). $329.95 plus $7 post. & insur. □ Same as above plus ASCII Keyboard Terminal With Cabinet, Gel Free RF Modulator (see above) . . . $499.95 phis $10 posl. & insur. □ Special 8" Disk Edition Explorer/85 (see above) . . $1496.95 plus $26 posl. & insur. □ Wired & Tested ... $ 1 799.95 plus $26 post . & insur. □ Extra R" CDC Floppy Drives. . . $499.95 plus $12 posl. & insur. □ Cabinet & Power Supply For Drive $69.95 plus $:t post. & insur. □ Drive Cable Set-up For Two Drives ... $25 plus $1.50 post. & □ Disk Controller Board With 1/0 Ports. . $199.93 plus $2 posl. & insur. □ Special: Complete Business Software Pak (see above) $699.96 postpaid. SOLD SEPARATELY: □ CP/M 1.4... $IOOposlpaid. □ CP/M 2.0... $l50poslpaid. □ Microsoft BASIC . . . $325 postpaid. □ Intel 8085 cpu User Manual . $7 .50 postpaid. □ Level "A" Monitor Source Listing ... $25 postpaid. ^ Continental USA. Credit Card Buyers Outside Connecucul ^ M CALL TOLL FREE: 800-243-7428 m ^H To Order From Connecticut Or For Technical ^V ^ Assistance, call (203) 354-9375 ^ Tola! Enclosed (Conn res. add sales lax) S Paid By: O Personal Check D Cashier's Check/Money Order D VISA a Master Charge (Bank No ) Add, No. Exp. Dale Signature Print Name Address City- Slab . Zip_ NETRONICS Research & Developmenl Ltd. 333 Litchfield Road, New Milford, CT 06776 rig] *1l%Ss I M* J COT, RflDIUS. UfUE fffiDED J gfigWi f|] ^[3]i'((I-«n])'2)«!J-flR[2] !»Z)«B.SMMP m LOOP 'iJ'ffC2]*ffii31)/JT SM0.1Ti[l\ mv- : : 7 «T RAM 17 T 1 *^^ -the memory that took 18 months to hatch ! 18 months ago, we designed RAM 17 around a brand new 16K static RAM from Hitachi that not only had the reliability and speed of static memory, but also consumed less power than dynamics. Unfortunately, pricing on this VLSI chip back then was such that we didn't feel RAM 17 would meet our tough standards for cost-effectiveness. In the past few months, however, volume production has lowered chip prices to where RAM 17 now represents an exceptional value in S-100 memory. Features include a stunningly low 250 mA typical power consumption, guaranteed operation (no wait states) at 6 MHz with CPU Z and 10 MHz with CPU 8085/8088, full compliance with all IEEE 696/S-100 specifications (including 24 bit addressing and standard board size), four optional 2K windows to accommodate memory mapped disk controllers, pinout compatibility with 2716 EPROM (allows RAM/ROM mix on a single board), plus all the other features that make CompuPro memory the first choice of system designers world-wide. $1595 CSC (2 year limited warranty), $1395 A/T (1 year limited warranty), $1095 Unkit. These features may appear to be those of a dream memory of the future. . . but CompuPro is delivering RAM 1 7 now at finer computer stores near you. CompuPro™ # division of (OjlBB i "ELECTRCmI :, OAKLAND AIRPORT, CA 94614 (415) 5620636 MEMBER on CompuPro computers don't JUST work: they WORK, and WORK, and WORK, and WORK, and If there's anything more important than throughput, it's reliability: that's why CompuPro System Components are painstakingly engineered not just to work, but to keep on working. Say goodbye to unexplained system hardware glitches - CompuPro products conform to all IEEE696/S-100 specifications, thereby ensuring well integrated (and predictable) system performance. Also, should a system malfunction ever occur, the bus oriented nature of S-100 machines allows you to simply pull out the bad board and plug in a replacement. . .and when you depend on a computer, you know what it means to minimize down time. All CompuPro products meet the most demanding mechanical and electrical standards, and are backed with one of the best warranties in the business (1 year limited warranty on all products, 2 year limited warranty with exchange program for products qualified under the Certified System Component program). Sure, computers can be great intelligent toys ; but for scientific, industrial, and commercial applications, toys aren't good enough. You need a computer that works, works right, and keeps on working : you need CompuPro system components. NEW! DISK 1: THE ULTIMATE a/t $495, csc $595 DISK CONTROLLER. Finally, a disk controller worthy of the CompuPro name. This state of the art design uses properly implemented DMA with artibration, meaning that Disk 1 can co-exist - without any conflict whatsoever- on the same bus as other DMA devices. And because Disk 1 has 24 bit DMA addressing (not memory mapped), you have access to a full 16 megabyte memory map. What about speed? Disk 1 transfers data independently of CPU speed, allowing operation with 6 MHzZ80s®* . Versatility? Disk 1 handles up to four 8" or 5.25" floppy disk drives (including 96 track high density minifloppies), single or double sided, single or double density (soft sector). Convenience? Disk 1 includes BIOS for CP/M-80®* ■, as well as on-board boot for automatic startup and on-board serial port for system initialization startup. Compatibility? Disk 1 is compatible with MP/M®* , OASIS, CP/M-80, and CP/M-86. Reliability? Uses industry-standard, third generation controller chips and the same design excellence that is a part of every CompuPro product. We weren't going to put out another me-too disk controller... and we didn't. The CompuPro Disk Controller is here. SYSTEM SUPPORT 1 MULTIFUNCTION BOARD $295 Unkit, $395 A/T, $495 CSC This multi-purpose S-100 board provides sockets for4K of extended address EPROM or RAM (2716 pinout) with one battery backup socket; battery backup month/day/year/time crystal clock with BCD outputs; optional math processor (9511 or 951 2); full RS-232 serial port; three 16 bit interval timers (cascade or use independently); two interrupt controllers service 15 levels of interrupts; power fail indicator; and comprehensive owner's manual with numerous software examples. Conforms fully to all IEEE 696/S-100 standards. (Add $195 to the above prices for the optional 9512 math processor.) SOFTWARE 8088/8086 MONITOR-DEBUGGER : Supplied on single sided, single density soft-sector 8" disk. CP/M®* compatible. Great development tool; mnemonics used in debug conform as closely as possible to current CP/M®* DDT mnemonics. $35. PASCAL/M* FROM SORCIM: PASCAL-easy to learn, easy to apply - can give a microcomputer with CP/M®* more power than many minis. We supply a totally standard Wirth PASCAL/M* 8" diskette and comprehensive manual. Specify Z-80* or 8080/8085 version. $175. Most CompuPro products are available in Unklt form, Assembled/Tested, or qualified under the high-reliability Certified System Component (CSC) program (200 hour burn-in, more). Note: Unkits are not intended for novices, as de-bugging may be required due to problems such as IC infant mortality. Factory service is available for Unkits at a flat service charge. r\ COMPUTER ENCLOSURE 2 Introductory price: $795 (specify rack mount or desk top version) Includes fused, constant voltage power supply ( + 8V at 25 Amps, ±16V at up to 6 Amps); 20 slot shielded/active terminated motherboard; and deluxe enclosure with dual AC outlets on rear, heavy-duty line filter, circuit breaker, quiet ventilation fan, and reset switch. Rack mount version includes slides for easy pull-out from rack frame. Also available: COMPUTER ENCLOSURE 1. Same as above, but less power supply and mortherboard. $289 desktop, $329 rack mount. PRICE BREAKTHROUGH ON 16K MEMORY EXPANSION - 8 RAMS/S29 These top quality, low power, high speed (200 ns) 16K dynamic RAMs expand memory in TRS-80* -I, -II, and -III computers (color model too) as well as machines made by Apple, Exidy, Heath H89, newer PETs, etc. Backed by 1 year limited warranty. Add $3 for two dip shunts plus TRS-80* conversion instructions. Limited quantity. S-100 MEMORIES FROM THE MEMORY LEADER CompuPro memories feature fully static design to eliminate dynamic timing problems, full conformance to all IEEE 696/S-100 specifica- tions, high speed operation (4/5 MHz Unkit, 10 MHz A/T and CSC), low power consumption, extensive bypassing, and careful thermal design. Unkit A/T CSC 8K RAM2A $159 $189 $239 16K RAM 14(extended addressing) $279 $349 $429 16K RAM 20-16 (extended addressing and bank select) $319 $399 $479 24K RAM 20-24 (extended addressing and bank select) $429 $539 $629 32K RAM 20-32 (extended addressing and bank select) ...$559 $699 $799 NEW! 64K STATIC RAM 17 . Amazingly low power in a 64K fully static RAM board: less than 500 mA maximum, 250 mA typical! It's fast, too; runs with 6 MHz Z-80®* CPUs, or 10 MHz 8080-family CPUs (8085, 8088, etc.). Uses IEEE extended addressing protocol, and may optionally turn off 2K windows from EOOO to FFFF in order to accommodate North Star or Morrow disk controllers (the CompuPro disk controller can use the full 64K since it employs properly implemented DMA techniques). $1095 Unkit, $1395 A/T, $1595 CSC. TERMS: Prices shown do not include dealer Installation and support services. Cal res add tax. Allow at Ieast5%shlpping; excess refunded. Orders under $15 add $2 handling. VISAW and Mastercard ® orders {$25 min) call our 24 hour order desk at (415) 562-0636. Include street address (or UPS delivery. Prices are subject to change without notice. FREE CATALOG : Want more information? Then send for our free catalog. For fast 1st class delivery, add 41 cents in stamps; foreign orders add $2 (refundable with order). •LEGAL CORNER: 280A is a registered trademark ot Zilog; TRS-80 is a Irademark of the Tandy Corporation. PASCAL/M is a Irademark of Sorcim; CP/M and MP/M are registered trademarks of Digital Research. COMPUPRO PRODUCTS ARE AVAILABLE AT FEVER COMPUTER STORES WORLD-WIDE. . .CALL (415)562-0636 FOR THE STORE NEAREST YOU. Circle 140 on inquiry card. CompuPro" division of pi»EJiJ ELECTRONICS^ OAKLAND AIRPORT, CA 94614 (415) 562-0636 BYTELINES News and Speculation About Personal Computing Conducted by Sol Libes Jony Enters Word-Pro- cessing Arena: The Sony Corporation is a real in- novator. First, it decided to enter the word-processing market. Then it introduced a new concept in word pro- cessing that's surely a win- ner. Called the Typecorder, it consists of a small key- board/ microcassette unit [about the size of two issues of BYTE. ...CW] that has a microcomputer and 1-line LCD display; it costs $1400. Small enough to fit into your briefcase, it permits you to create text, edit it, and store it on tape. The tape can be run off on a companion printer, available for $800, or through a word-processor system due later this year. You can transmit the text over telephone lines via an optional acoustic-coupler modem, or you can process the text through a non-Sony system. Typecorder lets you mix audio and digital infor- mation on cassette, so you might devise some interest- ing computer-assisted soft- ware. I have no doubt that Sony's concept, features, and low price will be popu- lar and will lead to applica- tions beyond word process- ing. ^Hk Close Look At The IBM Olsplaywrlter: IBM is now delivering its new low- cost Displaywriter word-pro- cessing system; it's only $1000 more than the Radio Shack TRS-80 Model II, and it's really a general-purpose microcomputer that uses the Intel 8088 microprocessor. IBM rents word-process- ing software for $50 per month, which sounds rather steep; however, consider the TRS-80 owner who uses WordStar. WordStar costs $500, plus another $150 for the CP/M operating system. Further, MicroPro Interna- tional issues WordStar up- dates about four times a year at $25 to $40 apiece. Hence, WordStar can cost a user about $850 for the first year of operation. My point is that the price difference between a word- processing system using an IBM (or Wang, Lanier, etc) and a Radio Shack system is really not that great. Add to this IBM's terrific service and its promises of extended I/O, communications, and applications packages for the Displaywriter, and you'll see that IBM is competing aggressively in the micro- computer marketplace. W. ord-ProcessIng Prices Dropping: Word- processing-system prices are dropping. Following on the heels of IBM's new low-cost word-processing system, Wang Laboratories has intro- duced a new stand-alone system for $7500, with dis- counts offered on multiple units. Lanier Business Sys- tems is expected to intro- duce an inexpensive system. A B Dick is planning a $7500 system that includes soft- ware (the others do not), and is drawing up plans for a local-network system that shares a printer, which will further reduce costs. Vomputer Hobbyists Gather For Huge Flea Market: On Saturday and Sunday, April 25th and 26th, several thousand computer hobbyists will flock to Tren- ton State College, Trenton, New Jersey, for the Trenton Computer Festival, the world's largest personal-com- puter-equipment flea market. This annual outdoor event is now in its sixth year. A multitude of swap and seller tables covering more than 5 acres of real estate feature everything from complete computer systems to tiny electronic parts. There will be speakers, user-group meetings, an indoor exhibi- tion area, and a banquet on Saturday night. The Festival is sponsored by the Amateur Computer Group of New Jersey, the Philadelphia Area Computer Society, and the Trenton State Computer Society. The funds raised help support these nonprofit organizations and their activities. For infor- mation, call (609) 771-2487, or write to TCF-81, Trenton State College, Trenton NJ 08625. Wredlt Cards With In- telligence? The Battel le Memorial Institute is study- ing the feasibility of a credit card with a built-in micro- processor. Such a card has already been developed in Europe and will soon be tested. It is expected that in- telligent credit cards will provide added security with- out requiring large computer networks. H ome- Inform at Ion Market Takes Shape: Several tests are underway to determine the best way to capture the lucrative home- information market. In the meantime, there's a battle brewing for control of the market, and the major con- testants are the telephone companies, principally AT&T (American Telephone and Telegraph) and the cable-television companies. By 1 983, AT&T is expected to launch its home-informa- tion systems. A user will probably have to buy a spe- cial video-display terminal, about $250, plus pay a monthly service fee in the $4 to $8 range. The cable-television com- panies plan to provide the same two-way services. Companies such as Westing- house, General Electric, and American Express are snatching up cable-tele- vision outfits. Several cable- television home-information systems are already in opera- tion. However, the real bat- tle is at least two years away when AT&T actually enters the market. I he Terminal You May Have Been Waiting For: Hewlett-Packard has introduced a super-intelli- gent terminal, called the Model 2626A. It displays 119 lines with 160 characters per line; moreover, the display can be divided into four win- dows. There are two inde- pendent I/O ports, so that you can simultaneously communicate through sepa- rate windows with two dif- ferent computers. There are user-programmable keys, and the bell has fifteen pitches, sixteen intensities, and two volumes— which means that you can play decent-sounding music on it. I Icrosoft And DEC Join Forces: Microsoft's first software product was a 4 K-byte BASIC interpreter, which used keywords similar to DEC's (Digital Equipment Corporation's) BASIC-Plus. It launched Microsoft on the road to success with expand- ed BASICs and other lan- guage packages. DEC has now adopted Microsoft BASIC for its GIG I (general imaging generator and inter- preter) color-graphics sys- tem. Microsoft's BASIC is contained in ROM (read- only memory) in a micropro- cessor-based unit. GIGI is used with the PDP-11 and VAX-1 1 systems. 212 April 1981 © BYTE Publications Inc Whether the job is building a home or a world MILESTONE helps... With today's concerns about increasing costs and declining productivity it is true more than ever that any project worth doing deserves careful planning. Whether your're planning a construction project or the opening of a new retail store, you must carefully schedulue your manpower, dollars and time in order to maximize productivity. MILESTONE is a critical-path-network-analysis program. It runs on a desktop microcomputer, is inexpensive and simple enough for anyone to use. MILESTONE'S design is a product of many years of experience in the "real world" of small-project management. In such an enivornment the primary purpose of planning is to help the project leader clar- ify the task at hand and to help him communicate his ideas to his subordinates and superiors. For these two reasons the designers of MILESTONE stressed it's interactivity and comprehensive reporting. Most of the design effort was put into eliminating unnecessary or redundant operator input and to checking all entries for validity. By organizing the project data for you, you can interactively modify your project plan leaving MILESTONE to perform the tedious calculations and to display the results. Internally, MILESTONE treats your project as a series of activities. Each activity has a name, dura- tion, capitol cost, mix of manpower, and an asso- ciated list of other activities that must be completed first. The list of associated activities (or prerequisites) provides a thread that MILESTONE uses to link all the jobs together into an overall project schedule. Every time you add a new activity or make a change to an existing one, the entire schedule is recomputed and the results are immediately redisplayed on the screen. For MILESTONE a project is simply any task made up of steps that must be performed in sequence. After dividing a project into it's composite steps, MILESTONE can help you plan, schedule and control the project. Specifically here are some of the things you can do, Find out which activities are time critical and can't be delayed Discover which activities have slack time and can be delayed without delaying the entire project Prepare a detailed cost estimate based upon a summation of each activity's individual equip- ment and manpower expenses Change an activity and instantly see the impact on the overall project schedule Investigate tradeoffs between manpower, dollars, and time Keep track of your project's progress by period- ically updating the schedule to reflect changes in the plan and completed activities MILESTONE requires 54K RAM and CP/M, Apple Pascal, or UCSD Pascal. CP/M versions need no sup- port language. All Apple II versions require 24 x 80 video card. Formats: 8" single denisty IBM soft- sectored, NorthStar DD, Micropolis Mod II, Super- brain 3.0, Apple II. Price is $295. Manual alone - $30. Add $7.00 for shipping. SOFW/1RE SOFTWARE DIGITAL AMRKETING DIGITAL/MARKETING 2670 CHERRY LANE WALNUT CREEK • CALIFORNIA 94596 • (415) 938-28BO MILESTONE trademark Organic Software CP/M trademark Digital Research Apple Pascal Trademark Apple Computer UCSD Pascal trademark Regents University California Circle 141 on inquiry card. BYTE April 1981 213 BYTELINES diagnostic Disk Troubleshoots Your Disk Drive: Dysan Corpora- tion will introduce a floppy disk that checks disk-drive operation. It contains soft- ware and geometric patterns that test radial positioning, linearity, hysteresis, eccen- tricity, index timing, skew, relative head positioning, azimuth, drive rpm (revo- lutions per minute), head load, access time, and head/ media compliance. The first model to be introduced will be a $40 IBM 3740-compati- ble 8-inch disk. w. ord-Processor Dic- tionary Introduced: IBM's new Displaywriter word-processor system fea- tures an optional dictionary- software package that checks the spelling of up to 70,000 words. Similar pack- ages will soon be available for other systems. The first is Microspell, to be distributed by Lifeboat Associates. It checks the spelling of any ASCII-text file stored on disk under CP/M. Thus, the pro- gram can be used with files created by WordStar, Word- Master, Magic Wand, and other word-processing pack- ages. I BM Status Report: Many critics want you to be- lieve that IBM's dominance in the data-processing mar- ket is eroding rapidly. Don't believe it, because more than a third of the $60 billion 1980 computer mar- ket was IBM's. In all in- dustry, IBM's $23 billion in sales ranked eighth, and its $3 billion in total profits was third. By contrast, the sec- ond largest computer maker, Burroughs, had $2.83 billion sales and $305.5 million in profits. IBM is not always the technological leader. Rather, it has used market- ing clout to establish domi- nance in any market it enters. For example, IBM sells 70% of the large main- frame computers in the USA. However, during the last few years, DEC (Digital Equipment Corporation), Data General, Wang Labora- tories, and Amdahl have grabbed an increasing share of the computer market. Several Japanese com- panies, such as Fujitsu, Hitachi, and NEC (Nippon Electric Company), are also moving in on IBM's territory. On the horizon, IBM faces strong competition from AT&T, Xerox, and Exxon, as they move into local and interoffice data-communica- tion network markets. These factors have had a serious impact on the value of IBM's stock. In the 1960 s, it sold for as much as 66 times earnings; it now sells for 15 to 20 times earnings. IBM's strategy for the 1980s is based on a coming generation of mainframes that will set new levels in price versus performance and emphasize telecom- munication networks. In ad- dition, IBM has opened retail stores and is entering several new markets via joint ventures, such as a videodisk project and satellite communications. However, it is likely that these projects will be a minor part in the whole IBM strategy for the 80s. Al- though IBM will become more involved in data net- working, its focus will con- tinue to be large central data-processing operations. IM, lew 8-Inch Win- chester Has 1 36 Mega- bytes: Ontrax Corporation has unveiled the largest capacity 8-inch Winchester- type disk drive to date. It stores 1 36 megabytes on five platters using sixteen read/ write heads. With a control- ler, the drive sells for $5000 in quantity. That's 0.004 cents per byte, compared to about 0.2 cents per byte for a typical single-density floppy-disk drive. R, random News Bits: Computerland, High Tech- nology, and The Computer Store plan to stock at least one Japanese-made personal computer. Japanese sup- pliers currently being con- sidered are NEC, Casio, Canon, Sharp, and Pana- sonic. ...Tandy Corporation and the Professional Farmers of America (PFA) have intro- duced Instant Update, a data-base service that uses TRS-80 videotext terminals (actually TRS-80 Model II). Via telephone connections, the service provides infor- mation affecting commodity prices and crop yields and gives access to Washington Watch News. Commodity prices are updated every 10 minutes. The service costs $95 per month. ...Sony has introduced a 3'/2-inch micro- floppy-disk drive. (Editor's note: See this month's editorial.) It is currently be- ing marketed to OEMs and systems houses; its capacity is reputed to be over 800 K bytes (unformatted) per disk. ...Two teenagers have been charged with masterminding a scheme that shut down DePaul University's comput- er during enrollment week. The shutdown cost DePaul $22,252 in computer time, repairs, and manpower. The teenagers said they did it to disprove the school's claim that it couldn't be done. ...Intel Corporation an- nounced its figures on net in- come and revenues for the year that ended December 31, 1980. Net income was $96.7 million, up 24% from the previous year, and revenues were $855 million, up 29% from 1979. Most of the growth occurred in the first half of the year.... R, random Rumors: In- formed sources say that Tan- dy will lower the price of its Videotext terminal to com- pete with AT&T's projected home-information terminal. ...Apple Computer is devel- oping a new microcomputer using the 16-bit Motorola 68000 microprocessor. ...At least one software-develop- ment house has leaked that it is seriously negotiating with Apple on a disk oper- ating system for a machine called the Apple IV. ...Look for a lower-priced version of Hewlett-Packard's HP-85 desk-top computer— maybe less than $2000— to be call- ed the HP-83. It lacks some of the HP-85's features, but it has a plug-in disk-drive op- tion. ...Exxon's Kylex division is developing a 40-row by 80-character LCD (liquid- crystal display) for computer-display terminals. ...Sony might be developing a personal-computer system for this year's market. Sony may include an interface for its new Typecorder word- processor terminal. ...Digital Equipment Corporation is developing a new line of per- sonal-computer products with extensive software sup- port, including an operating system based on RT-11 with VAX-compatible BASIC... WOBOL For The 8086 Announced: The software picture for 8086-based 16-bit microcomputer systems keeps improving. Seattle Computer Products has an- nounced an 8086 version of Microsoft BASIC. Now Microsoft has COBOL-86, which runs under the CP/M-86 operating system. The projected execution time of these packages is three times as fast as the 8080/Z80 versions. As a re- sult of the 8086's multitask- ing capabilities, the pack- ages will be better suited for multiple-user systems than the 8-bit versions. MAIL: I receive a large number of letters each month as a result of this column. If you write to me and wish a response, please include a stamped, self-addressed envelope. Sol Libes POB 1992 Mountainside NJ 07092 214 April 1981 © BYTE Publications lnc ALL THESE FEATURES... IN THIS SMALL SPACE... AT THIS LOW PRICE! Greater computer power . . . fewer separate components . . . larger capability . . . simpler to operate . . .. modular maintenance . . . These are the unique benefits of the Quasar Data QPD-100 Floppy Disk Computer . . . plus unsurpassed reliability... plus 12-month warranty on all PC boards. Its highly reliable, industry-standard MFE drive is compact. Accepts both single AND double-sided disks. Upgradeable from the Z-80® microprocessor-based system to our ZSOOO^ microprocessor-based system by simply plugging in extra PC cards. Hard disk and multi-user systems available. As your requirements grow, your QDP-100 can grow to fit them. The Quasar Data QDP-100H is a larger version with 6-megabyte capacity; includes one double-sided floppy and one 5 1 /t microwinchester hard disk. Both the Quasar Data QDP-100 and QDP-100H are fully compatible with all standard terminals. Phone or write for descriptive bulletin and specifica- tions. And ask for a demonstration. Dealer inquiries invited. QUASAR DATA'S QDP-100 COMPUTER SYSTEM. 4,695 1 8" wide 16%" deep 11" high Complete systems available '" Z-80 and Z-8000 are trademarks of Zilog Corporation ~CP/MandMP/M are trademarks of Digital Research Corp Circle 142 on inquiry card. 10330 Brecksville Road, Brecksville (Cleveland), Ohio 44141 Phone: 216/526-0838 / 526-0839 Telex: 241596 BYTE April 1981 215 SiiperSofft's Gallery of CP/M Ma§{erwork§ u SUPER-M-LIST: A complete, easy to use mailing list program package. Allows for two names, two addresses, city, state, zip and a three digit code field for added flexibility. Super-M-List can sort on any field and produce mailing labels direct to printer or disk file for later printing or use by other programs. Super-M-List is the perfect companion to TFS. Handles 1981 Zip Codes! Requires: 48K CP/M Supplied with complete user manual: $75.00 manual alone: $10.00 TFS-Text Formatting System: An extremely powerful formatter. More than 50 commands. Supports all major features including: • left & right margin justification • userdefined macros • dynamic insertion from disk file * underlining and backspace TFS lets you make multiple copies of any text. For example: Per- sonalized form letters complete with name, address & other inser- tions from a disk file. Text is not limited to the size of RAM making TFS perfect for reports or any big job. Text is entered using CP/M standard editor or most any CP/M compatible editor. Requires: 24K CP/M Supplied with extensive user manual: $85.00 manual alone: $20.00 Source to TFS in 8080 assembler (can be assembled using stan- dard CP/M assembler) plus user manual: $250.00. TEXT PROCESSING R DIAGNOSTICS I: Easily the most comprehensive set of CP/M compatible system check-out programs ever assembled. Tests: • Memory • CPU (8080/8085/Z80) • Terminal • Disk • Printer To our knowledge the CPU test is the first of its kind anywhere. Diagnostics I can help you find problems before they become serious. A good set of diagnostic routines are a must in any program library. Minimal re- quirements: 32K CP/M. Supplied with complete user manual: $75.00 Manual alone: $15.00 DIAGNOSTICS II: Includes all of Diagnostics I, plus: • Every test is "submit"-able • A complete Spinwriter/Diablo/Qume test has been added (Serial Interface only) • Output may be logged to disk • Expanded memory test • Expanded terminal test Expanded disk test Diagnostics ll provides the next level in system maintenance. Requires: 32K CP/M Price: $100.00 Manual only: $15.00 SYSTEM MAINTENANCE A i tit i tut i t A A A * * i A * * A A faA 'TINY' PASCAL II: We still call it Tiny' but it's bigger and better than ever! This is the famous Chung-Yuen 'Tiny' Pascal with more features added. Features include: • recursive procedures/functions • integer arithmetic * CASE • FOR (loop) • sequential disk I/O • 1 dimensional arrays • IF.. .THEN. ..ELSE • WHILE • PEAK & POKE • READ & WRITE ■ REPEAT.. .UNTIL • more Tiny' Pascal is fast. Programs execute up to ten times faster than similar BASIC programs. SOURCE TOO! We still distribute source, in Tiny' Pascal, on each discette sold. You can even recompile the compiler, add features or just gain in- sight into compiler construction. Requires: 36K CP/M. Supplied with complete user manual and source on discette: $85.00. Manual alone: $10.00 STACKWORK'S FORTH: A full, extended Forth interpreter/compiler produces COMPACT, ROMABLE code. As fast as compiled FORTRAN, as easy to use as in- teractive BASIC. SELF COMPILING: Includes every line of source code necessary to recompile itself. EXTENSIBLE: Add functions at will. Z80 or 8080 ASSEMBLER included. Single license, OEM licensing available. Please specify CPU type: Z80 or 8080 Supplied with extensive user manual and tutorial: $175.00 Documentation alone: $25.00 SSS FORTRAN: The SSS FORTRAN compiler is fast, efficient, and complete (full 1966 ANSI standard with extensions). The RATFOR compiler compiles into FORTRAN allowing the user to write structured code while retaining the benefits of FORTRAN. The FORTRAN supports many advanced features not found in less complete implementations, including: complex arithmetic, character variables, and functions. Complete sequencial and random disk I/O are supported. SSS FORTRAN will compile up to 600 lines per minute! Recur- sive subroutines with static variables are supported. ROMable ".COM" files may be generated. SSS RATFOR allows the use of contemporary loop control and structured programming techniques. SSS RATFOR is similar lo FORTRAN '77 in that it supports such things as: • REPEAT.. .UNTIL " WHILE • IF.. THEN. ..ELSE SSS RATFOR is supplied with source code in FORTRAN and RATFOR. System Requirements & Prices: SSS FORTRAN requires a 32K CP/M system. SSS FORTRAN with RATFOR: $325.00 SS FORTRAN alone: $250.00 RATFOR alone: $100.00 (Sold only with valid SSS FORTRAN license) i ^f* 1 ♦ **$** ♦ W ♦ "*♦ * * 1 PROGRAMMING LANGUAGES fr** f w f" j M j w f'"^ UTILITIES I: A collection of programs that you will find useful and maybe even necessary in your daily work (we did!). Includes: GREP: Searches files for a specified string SORT: In core sort of variable length records CMP: Compare two files for equality PRINT: Formatted listings to printer PG: Lists files to CRT a page at a time . . . plus more . . . Requires: 24K CP/M Supplied with manual on discette: $60.00 UTILITIES II: Many new programs not available elsewhere. Includes these "file" utilities: DIFF: Source comparitor PR: Powerful multicolumn output formatter CAT: Concatenate files RPL: Substitute strings in files . . . plus more . . . Requires: 24K CP/M $60.00 Supplied with manual on discette UTILITIES TERM: A complete intercommunications package for linking your com- puter to other computers. Link either to other CP/M computers or to large timesharing systems. TERM is comparable to other systems but costs less, delivers more and source is provided on discette! With TERM you can send and receive ASCII and Hex files (COM too, with included conver- tion program) with any other real time communication between users on separate systems as well as acting as timesharing terminal. • Engage/disengage printer • errorchecking and auto retry • terminal mode for timesharing between systems • conversational mode • send files • receive files Requires: 32K CP/M Supplied with user manual and 8080 source code: $150.00 Manual alone: $15.00 ^INTERCOMPUTER COMMUNICATIONS! Mii ANALIZA: An amazingly accurate simulation of a session with a psychiatrist. Better than the famous "ELIZA" program. Enlightening as well as fun. An excellent example of Artificial Intelligence. Requires: 48K CP/M, CBASIC2 Cost: $35.00 ENTERTAINMENT ft , ,..- : , : :; : ,-, "■"'.;- , '"■■.;,',;. '" :; u Cl> Z8000CROSSASSEMBLER:Supports: full Z8000 syntax, segmented and : , : unsegmented mode, full 32-bit arithmetic, hex output, listing output, U-. '■>.-' "downloader". V. :""'. Requires: 56K CP/M $500.00 1 year maintenance $300.00 W :' l"i manual alone $ 50.00 ; - $ > .;- -■,_'■ - - A zeoootoo! J - :< =; ^ ^ ENCODE/DECODE: A complete software security system for CP/M. Encode/Decode is a sophisticated coding program package which trans- forms data stored on disk into coded text which is completely unrecog- nizable. Encode/Decode supports multiple security levels and passwords. A user defined combination (One billion possible) is used to code and decode a file. Uses are unlimited. Below are a few examples: • databases • payroll files • programs • tax records Encode/Decode is available in two versions: Encode/Decode I provides a level of security suitable for normal use. Encode/Decode II provides enhanced security for the most demanding needs. Encode/Decode I: $50.00 Encode/Decode II: $100.00 manual alone: $15.00 ^ ^ SOFTWARE SECURITY f On line "Help" system provided with every program package. SuperSoft First in Software Technology CP/M Formats: 8" soft sectored, 5" Northstar, 5" Micropo- lis Mod II, Vector MZ, Superbrain DD/QD All Orders and General Information: SUPERSOFT ASSOCIATES P.O. BOX 1628 CHAMPAIGN, IL 61820 (217)359-2112 Technical Hot Line: (217) 359-2691 (answered only when technician Is available) CP/M REGISTERED TRADEMARK DIGITAL RESEARCH SuperSofffs DIAGNOSTICS I & II for CP/M Since the beginning, programs have been written to verify the correctness of computer systems. This task has usually fallen on the manufacturers of computer equipment. However in the case of microcomputers, the manufacturers have been reluctant to supply such programs along with their hardware. First, because they often are not the ones called on to fix that hardware, and second, because the low cost of such systems often does not allow for such a large programming effort. The tremendous number of CP/M systems have made it possible for us to offer both DIAGNOSTICS — I & II at an affordable price, since we do not have to deal with a myriad number of console devices and disk systems, we simply use the standardized system calls. Both packages perform tests on the five critical areas of your computer system: • Memory • CPU • Printer • Terminal • Disk drive DIAGNOSTICS-I provides an excellent level of testing. DIAGNOSTICS — II is simply the finest set of system maintenance routines ever written for microcomputers. DIAGNOSTICS — II includes all of DIAGNOSTICS — I. but goes much further in providing the user with even more checks, tests, and reports. DIAGNOSTICS-I Features The MEMORY TEST allows every byte of user memory to be tested. Both a quick test as well as a walking bit' test are included. Error reports summarize errors by bit as well as address. The CPU TEST interprets a program that is designed to execute all single instruction sequences and many multiple instruction sequences. After each instruction sequence, the program tests all of the CPU registers to see that the proper registers changed correctly, and only those registers changed. This will detect, for instance, if storing into the A register affects the B register. The CPU test will automatically recognize the type of CPU you have. To the best of our knowledge, nothing as powerful as the CPU test is available anywhere else. The PRINTER TEST prints a one line pattern, then rotates the pattern one character and prints again. This barber pole' scheme is simple, yet elegant, since it checks that every printable character can be printed in every printer column, and does so in a manner that makes any error obvious at a glance. The TERMINAL TEST prints a 'barber pole' and then exercises cursor positioning, foreground, background, erase- all, erase-to-end-of-line, erase-foreground, and erase-background. If some of these features are not available on your terminal, they can be skipped. The test can be used with any terminal; many standard types are supplied pre-patched. any other can be patched by the user. The DISK TEST writes a unique pattern in each sector, and then does a pseudo-random seek/read test within the file area. DIAGNOSTICS-II Features Every test is "submit'-able. In fact, a sample submit file is provided with each disk. This means that the user can run a series of tests without operator interaction. To further decrease the need for the user to "baby sit' the tests, the output of tests may be logged to disk for later review. This makes overnight testing very easy yet informative. We started with DIAGNOSTICS — I and added all the features that users wanted as well as some of our own. Below is a description of some of the enhancements. MEMORY TEST: • Default to size of CP/M TPA • Bank select (a necessity for more than 64k) • Memory map of system displayed • Memory speed test • Burn in test PRINTER TEST: • Spinwriter, Diablo, Qume test which checks all head and carriage motions as well as ASCII printing features. (This is a very thorough test!) DISK TEST: • Writes a unique pattern to each sector on disk, verifying as it runs. • User defined seek patterns allowed (This is great for drive allignment and testing!) • Tests user specific user defined sectors. The TERMINAL TEST is the same as for DIAGNOSTICS — I except that it is submit -able. The CPU TEST is the same except that it is "submit -able and output may be logged to disk. Also, a QUICK TEST has been added which willcheckthe memory, disk drives, and CPU in your system in less than four minutes! The test is, of course, not as thorough as the ones described above, but provides a measure of confidence. It is particularly useful if used every time the system is powered up. SISSIES !i $ I?£?™ *» Orders and General Information: DIAGNOSTICS II: $100.00 Cfm*rOi# P^S^ SUPERSOFT ASSOCIATES DIAGNOSTICS II: $100.00 ft/rwCV/ F^S^ SUPERSOFT A (manual only): $15.00 JUJjXLSf^i \mmm* P.O. BOX 1628 Both require 32K cp/m First in Software Technology CHAMPAIGN, IL 61820 (217)359-2112 Technical Hot Line: (217) 359-2691 __,.._ „„ _,„„.., „,,., (answered only when technician Is available) CP/M Formats: 8 soft sectored, 5 Northstar, 5 Micropo- lis Mod II, Vector M2, Superbrain DD/QD -civm nEosre»fD tiudem»mhhgit«l heseauch An Introduction to Data Compression Harold Corbin 11704 Ibsen Dr Rockville MD 20852 Even though the cost of data storage continues to decrease fairly rapidly, there are still a number of situa- tions where it is desirable to squeeze more data into a physical storage device. Often the typical microcomputer has limited memory, small disks, or slow cassettes. With any of these storage limitations, data compression may offer a method of using the existing device to store larger quantities of data or to provide improved access time to the data. The use of data compression can also provide significant improvement in the transmission of data over communication networks since there are fewer bits to send in order to convey the information. ASCII code does not consider that the frequency of the characters in the file is not uniform. The basic idea in data compression is to use more effi- cient codes to represent the information in a file or to re- move redundant and unnecessary information from the file. With data compression in effect, the system stores or sends only the minimum data necessary to convey the original information. In a typical file, the individual characters are represented by fixed-length codes such as ASCII (American Standard Code for Information Interchange). This representation does not consider that the frequency of occurrence of the characters in the file is not uniform. In typical English text, E is the most common letter and Z is the least frequently used letter. Table 1 presents a fre- quency analysis for letters in English text. Using a code such as ASCII for storing or transmitting text means that the same number of bits is used for the most frequently occurring letter as well as for the least frequently occur- ring letter. This method of encoding data uses more bits to represent the information in the file than is necessary. In this article, I will illustrate ways to store data more efficiently. Encoding the data in a more efficient form is called data compression. There are a variety of methods that have been used to compress data, but all of them attempt to reduce the redundancy of the original data. Most large data-processing systems provide some form of file com- pression, since storage costs money. Also, it is often less expensive to pay for the computer time to compress and expand the data than to pay for mass storage. The user of a large system usually has PACK and UNPACK com- mands available to allow compression and expansion of his files. Typical data-processing systems use some form of zero or space suppression to do their data compression. This method is easy to implement and not very expensive to run, and produces fairly good compression for many types of data. The efficiency of this compression method is dependent upon how many spaces or zeros occur in the file. Typically, a source file of assembly-language state- ments is a good candidate for data compression. Fifteen to twenty percent compression of an assembly-language source file is not uncommon. Data-Compression Methods A space-compression capability can be implemented in several ways. Two common ones are bit mapping and recurrence coding. In the bit-mapping scheme, a bit map exists that is long enough to match one bit of the bit map to each byte of data in the original file. In the map, a is stored for each byte in the data that is a space, and a 1 is 218 April 1981 © BYTE Publications tac THE PERFECT MARRIAGE CHRISLIN 256KB MEMORY iWfi-U I Si ^^j . ^^L ^M ^M |Mj| g^^ ^^ ^_ . :jm PI PR 5S 181 5K1S8 5- ^5 . \-.' ; .'.; ^' B B 9 B B B B 9 9 VII, •;,.. ;^« j^| ^k ^^ ^| |m i^ |^-|g|" * ^Lj^'- ' ' B B B B B B BB \m y' Ufmik iiiul&iii iinniimimm luivam« DEC® LSI® 11/23 NOW AVAILABLE! 256KB memory on a dual height board only $1925. CHRISLIN INDUSTRIES now offers state-of-the-art 64K RAM Memory system designs. Like our recently introduced 512KB MULTIBUS® compatible single card memory our 256KB LSI 11/23 memory is an industry first. Free up critical and expensive backplane space. Saves you 3 dual slots. Addressable in 4K increments up to 4 Megabytes. On board parity generator checker totally DEC hardware and software compatible. Single 5 volt power requirement. Battery back-up capability. 256KB unit draws less than 300 ma at 5 volts in battery back-up mode. Tested and burned in. Full year warranty. DON'T ASK WHY WE CHARGE SO LITTLE, ASK WHY THEY CHARGE SO MUCH. £ Chrislin Industries, Inc. Computer Products Division 31352 Via Colinas • Westlake Village, CA 91362 • 213-991-2254 Multibus is a trademark of the Intel Corp LSI II is a trademark of Digital Equipment Corp Circle 143 on inquiry card. BYTE April 1981 219 stored in the map for each corresponding byte in the data that is not a space. This way, the data can be stored with all spaces removed and still be easily reconstructed by first examining the bit map to determine where the ex- panded file needs to have a space or spaces inserted as the next data byte. Recurrence coding takes a string of more than two repetitive characters and replaces the string with a special character. It is then followed by the count of how many occurrences of the repeated character are being com- pressed. A variation of this method is used in the IBM VM/370 Operating System with the PACK option of the COPYFILE command. If the string "ABbbbbCD" (where b is a space) were to be compressed using the bit-mapping technique, 5 bytes would be required to store the data and the bit map. The map would be 11000011 (1 byte) and the data would be "ABCD" (4 bytes). Since only 5 bytes are required to store the original data in compressed form instead of 8 bytes, the data is compressed to 62.5% of its original length. Storing the same string using recurrence coding would result in a compressed string of "AB*4CD", where "*4" replaces the four spaces. In this case, the data is compressed to 75% of its original length. You can see that the efficiency of a given method is dependent upon both the method itself and the characteristics of the data's redundancy. Another method of compression is known as pattern substitution. In this method, each occurrence of a specific pattern is replaced by a unique code. For example, in the above text, the pattern "compression is" could be replaced by a single 8-bit byte — say, 11111001. This would compress each occurrence of the 14 ASCII bytes in the pattern to a single byte. Obviously, if there were more than 256 patterns, the code pattern would have to be bigger than 8 bits to maintain uniqueness. Variations of this method could mix the ASCII code and the pattern code. One scheme would place a unique code — for example, the ASCII ESC (escape) character — ahead of the pattern code. When the PACK routine en- counters the ESC character, the next byte is replaced with its equivalent pattern. Another scheme that would permit ASCII and pattern codes to be mixed would tag the pattern codes by setting the high-order bit to 1. This would restrict the ASCII to 128 codes and the patterns to 128 codes. The efficiency of the pattern-substitution compression methods can be very useful if the pattern is long and its number of recurrences is high. Some compression systems based upon this method have sophisticated pro- grams that search the data for patterns and assign codes to the patterns in an optimal manner. Some compression methods are data-value dependent. One of these methods is difference compression. For example, if succeeding records had a field with the following values: 1,732,517 1,732,217 1,732,200 1,732,190 either the difference between succeeding fields or the dif- ference from a base value could be stored as the com- pressed data. In the first case, the values 1,732,517 300 17 10 would be stored. Obviously, if the field is of fixed length, nothing is gained by compression. However, if a variable field-length capability exists in the system, some space savings can be achieved with this compression method. Again, the amount of compression is highly dependent upon the data and its characteristics. Another compression method makes use of the statistical properties of the occurrence of the data to be compressed. In this method, shorter codes are used for the more frequently occurring data elements. Longer codes are used for less frequently occurring data elements. One code used in data compression that op- timizes the encoding values is the Huffman code. There Letter Frequency (%) E 13.0 T 10.5 A 8.1 7.9 N 7.1 R 6.8 1 6.3 S 6.1 H 5.2 D 3.8 L 3.4 F 2.9 C 2.7 M 2.5 U 2.4 G 2.0 Y 1.9 P 1.9 W 1.5 B 1.4 V 0.9 K 0.4 X 0.15 J 0.13 Q 0.11 Z 0.07 Table 1: Relative fre- quency of the alphabet in the English language. In most ch aracter codes (in- eluding the common 7-bit ASCII), every letter is represer ted by the same number of bits. But one method of data compres- sion assigns shorter codes to the frequently used let- ters (ie: E, T, and A) and longer codes to seldom used letters (ie: Q and Z). A message stored in this kind of code should be significantly shorter in bits than th e same message stored in ASCII. Letter Huffman Code E 100 T 001 A 1111 1110 N 1100 R 1011 1 1010 S 0110 H 0101 D 11011 L 01111 F 01001 C 01000 M 00011 U 00010 G 00001 Y 00000 P 110101 W 011101 B 011100 V 1101001 K 110100011 X 110100001 J 110100000 Q 1101000101 Z 1101000100 Table 2: A Huffman code. There are many Huffman codes; this is the one that is used in figure 2 and listings 1 thru 4. Note that the shorter codes are used for frequently occurring letters, and that no code is a beginning substring of a longer code. The average number of digits used to represent a letter can be reduced toward the entropy limit H if the Huffman tech- nique is used to encode blocks of letters rather than individual ones. 220 April 1981 © BYTE Publications Inc A TO GROWTH A year ago, the course for Marot Software Systems, Inc. was clear. We were on our way to becoming the world's best source for software. And we were going to accomplish that by distributing only the operating system and the application software that brought out the best in micro- computers. That was our course... and, in all modesty, we were most successful. That's when something funny happened. The dealers, consultants and computer users with whom we had relationships began asking — and then demanding— that we at Marot apply our expertise and follow-through to the supply of reliable, quality-oriented hardware and complete computer systems. Systems that could solve specific problems in data -based manage- ment and analysis for business, law, medicine, science and government. Here's the hardware we now distribute: ONYX — Extremely powerful and reliable 5-user Z80-based micro, with 10 or 20 Mb hard disk and integral tape sub- system. Also available: 16 bit Z8000 operating UNIX™ Version 7, with up to 1 Mb RAM for as many as 8 users. 10 or 18 Mb hard disk with integral tape subsystem and additional storage available. ALTOS — Cost-effective floppy disk system, 208 K RAM for up to 4 users. Expansion to 58 Mb hard disk with tape backup available. The marketplace told us of the need for support, too. Of the gap that existed in matching hardware, operating systems and software to application requirements. And of the need for assistance in evaluating options available to meet those requirements. So, we thoroughly searched and found the best hardware we could distribute. As a result, Marot Software Systems, Inc. has become Marot Systems, Inc. It's the one company you can rely on to handle total computer needs: from hardware, software, operating systems and support to total computer solutions. If you're a computer dealer or a computer consultant, Marot's total backup and support could be the special something you need to make your operation grow. Call or write us today. Here are the products distributed by Marot Systems, Inc. Please check items of interest and return this coupon to: Marot Systems, Inc. 310 Madison Avenue, Suite 408 New York, New York 10017 (212)661-8550 Please send me more information on the following: Operating System □ OASIS® — The mini-like single and multi-user machine- independent operating system for Z80 commercial applications and serious programmers. Name MAROT SYSTEMS YOUR EASTERN SOURCE Software □ MAGIC WAND™ — The most usable full- feature word processing system with extremely powerful text-formatting features. □ MAROT'S MAILING LIST PROGRAM — Maintains up to 65,000 entries in zip and name order, by ISAM files. □ COMPLETE BUSINESS PACKAGES — In standard ANSI 74 COBOL. Five module accounts receivable, accounts payable, general ledger, payroll, order entry/inventory plus financial modeling and job costing. □ ESQ-1™ — Time and billing system for the legal profession. D MAROT'S OFFICE APPOINTMENT SCHEDULER — Maintains complete office diary, with ability to compare schedules. Title Company Address City/State/Zip. . Phone ( Hardware □ ONYX □ ALTOS □ CORVUS HARD DISKS — 10 or 20 Mb, available for many computers including Tandy's TRS-80®Modll □ PERKIN-ELMER TERMINALS □ TELEVIDEO® TERMINALS □ XEROX® PRINTERS I am a □ computer dealer D computer consultant □ computer user ESQ-1 is a trademark of Micro Information Systems, Inc. TRS-80 is a trademark of Tandy Corp, OASIS is a product of Phase One Systems. MAGIC WAND is a trademark of Small Business Applications Inc. Circle 144 on inquiry card. BYTE April 1981 221 are actually many Huffman codes, but they are similar in structure. Before explaining how to construct a Huffman code, I will describe a typical Huffman code and how it works. The code that is used in the two compression programs in this article is given in table 2. To compress the word "compression", the appropriate CODE LENGTHS L ARRANGED IN ASCENDING ORDER I . IS NEW CODE SAME ] LENGTH AS F I LAST CODE | ADD 1 TO LAST CODE TACK ON ZEROS EQUAL TO THE DIFFERENCE IN CODE LENGTH ONTO RIGHT-HAND END OF CODE ( END J Figure 1: Flowchart for assignment of Huffman codes. This algorithm will produce a series of codes (Huffman codes) with the following two characteristics: the length of the code (in bits) is inversely proportional to the relative frequency of the symbol being encoded; and no code is a beginning substring of the Huff- man code of another symbol. Together, these properties define a code with a unique decoding that uses the smallest number of bits to encode an average message. binary code is assigned to each letter, which produces the binary string: , 01000111000011110101101110001100110101011101100 , \ AAA A A A A A A A / COM R E S S I O N A quick count shows that 47 bits were required to en- code the word "compression" with Huffman coding as compared to the 88 bits required with ASCII code. This gives a compressed text that is 53.4% of its original length. This level of compression is not too surprising since it is well known that the English language is highly redundant. Of course the above example is a very short one. A larger piece of data should be used to find a more exact value of the amount of compression that can be expected from using Huffman coding. The actual efficiency can also be determined mathematically, but an explanation of that method is beyond the scope of this article. Using the program code described above with English text, approx- imately 4.18 bits would be required for each letter. Com- pared to 8-bit ASCII code, the compressed text is com- pressed to 52.2% of its original length. Earlier in this article I mentioned that Huffman codes are optimized based upon the probability of the occur- rence (ie: frequency) of the data element being encoded. In the program-code table (table 2), the more frequently occurring letters have the shorter codes, (eg: an E is coded with 3 bits). The number of bits, b, needed to encode a letter can be determined by the following formula: b = /(-log 2 p) where p is the probability of occurrence of the letter, and f(x) is the closest integer greater than or equal to x. From table 1, the probability of occurrence of an E in English text is 0.13; since — log 2 0.13 = 2.94, the integer length is 3. If you were to continue to compute the code lengths from the probabilities in table 1, the lengths would differ from the code lengths used in the programs. This is because the program code lengths were deter- mined from text that differs slightly in frequency from the text used to prepare table 1. There are several ways the actual codes can be con- structed. One method is shown in figure 1. To use the algorithm in figure 1, the letters must be arranged by m 1 COLOR lilli§*lii ^^*^ MONITOR/RECEIVER :\4§HB Jsi| Two Modes of Operation for The Price of One llllifi§ -3S8p f 'WHS. ""* ,: >* • Standard composite video/ 75 ohm term. • Transformer isolated for safety. • External audio input with control. 1 • Power Requirements: 1 17 VAC 60 Hz. • VM-19, 19" diagonal screen, $575.00. • For professional, industrial, home video applications. VM-I3 * V.A.M.P. Inc. P.O. BOX 29315 . LOS ANGELES, CA 90029 . (213) 466-5533 222 April 1981 © BYTE Publications Inc Circle 145 on inquiry card. If you want a choice in print wheels, # there's only one choice in printers. The Diablo 630. It's the only printer that lets you use either metal or plastic print wheels. So you can choose the print wheel that's just right for the job. The 630 works as well with a 96-character plastic daisy print wheel as it does with an 88-, 92-, or 96-character metal daisy print wheel. In over 100 different type styles. Every 630 has fewer moving parts than competitive printers, which makes it more reliable. And it offers unsurpassed print quality. Compatibility with Diablo supplies. And bi-directional printing capability. The 630 is the only printer in the world that uses both metal and plastic wheels. So if you want to change your print wheels, you'll just have to change your printer. To a Diablo 630 printer. saw*-*' I Diablo Systems XEROX Diablo* ami XEROX® arc trademark of XEROX CORPORATION. Circle 146 on inquiry card. BYTE April 1981 223 Stack Work's A full, extended FORTH interpreter/compiler produces COMPACT, ROMABLEcode. As fast as compiled FORTRAN, as easy to use as interactive BASIC. SELF COMPILING Includes every line of source necessary to recompile itself. EXTENSIBLE Add functions at will. CP/M* COMPATIBLE Z80or 8080 ASSEMBLER included Single license Supplied with extensive user manual and tutorial: $175.00 Documentation alone: $25.00 OEM's, we have a deal for you! CP/M Formats: 8" soft sectored, 5" Northstar, 5" Micropolis Mod II, Vector MZ.TRS-80 Mod II Please specify CPU type. Z80or8080 All Orders and General Information: SUPERSOFT ASSOCIATES P.O. BOX 1628 CHAMPAIGN, IL 61820 (21 7) 359-2112 Technical Hot Line: (217) 359-2691 answered only when technician is available) SuperScft First in Software Technology *CP/M registered trademark Digital Research V G U M Figure 2: Binary tree for a Huffman code. The Huffman code for a letter is defined as the sequence of binary digits encountered when tracing the path from the root node, *, to the letter. Thus, the code for G is 00001, and the code for E is 100. This is the code used in the programs of listings 1 thru 4. Although this code cannot be produced by the algorithm of figure 1, it is a valid Huffman code (there are many) that can be validly used to illustrate the structure and implementation of Huffman codes in general. ascending code length. Then the letter with the shortest length is assigned a code consisting of all Os. Execution of the algorithm will result in the assignment of a unique code to each letter. With any set of codes that are constructed, it is impor- tant that no code has a shorter code as part of its begin- ning. For example, if E is 100, then 10010 cannot be the code for another letter. This is because in scanning the bit stream from left to right, the decoding algorithm would think that 10010 is E (100) followed by 10 and not the dif- ferent letter that was intended. Regardless of the method used to construct the codes, the full set of binary Huffman codes can be represented as a binary tree. Figure 2 shows the binary tree that is equivalent to the Huffman code used in the programs of listings 1 thru 4. (These codes were not produced by the algorithm of figure 1.) This code structure allows the code to be uniquely decoded by simply starting at the top of the tree and walking down the tree, taking each branch that corresponds to the bit value, 1 or 0, as the coded data stream is scanned from left to right. This is the way the expansion program recreates the original data. It is possible to combine various compression methods to increase the storage efficiency even more than when working with single letters. For example, Huffman codes could be assigned to patterns. Instead of working with the frequency of letters, you would use the frequency of the patterns. Thus, the pattern "code" might be represented by 010 and the pattern "data compression" might be represented by 10110. Obviously, a lot of com- pression could be achieved, particularly if single-letter and pattern methods are combined and certain patterns have a high frequency of occurrence. Sample Programs Two versions of both the compression and the expan- 224 April 1981 © BYTE Publications Lie MORE BANG Qantex Impact Printers 150 Characters Per Second 136 Columns Per Line The microprocessor controlled Series 6000 is packed with standard features. True lower case descenders and underlining. Bidirectional logic seeking. Built-in test capability. Rugged 400 million character print head. Beautiful 96 character set in a 9x9 matrix. Parallel, or up to 19,200 baud serial interfaces supporting RS-232, X-ON, X-OFF or Current Loop. Full operator con- trols. Quietized, sleek enclosure to en- hance your system. Delivery from stock. Qantex Division of North Atlantic Industries 60 Plant Avenue, Hauppauge, N.Y. 11787 (516) 582-6060 TWX 510-227-9660 (800) 645-5292 For more information call your local distributor: ARKANSAS Little Rock Hemco Electronics 501-663-0375 ARIZONA Tempe Qualtech 602-967-4655 LOUISIANA New Orleans Micro Computer Of New Orleans 504-885-5883 AUSTRALIA Sydney Mitsui Computer Systems 32-9299921 ARIZONA Tempe PGI Wholesale 1-800-528-1415 CALIFORNIA Ingle wood Basic Systems 213-673-4300 MINNESOTA Edina Integrated Peripherals 612-831-0349 BELGIUM Brussels Compudata Belgium 7205066 CALIFORNIA San Diego Basic Systems 714-268-8000 MINNESOTA St. Paul Vikeland Sales 612-645-4647 CANADA Toronto Computer Markets 416-445-1978 CALIFORNIA Santa Clara Basic Systems 408-727-1800 MISSOURI Independence Computer Dataco 81 6-254-3600 ILLINOIS Addison Engineered Sales 312-832-8425 MISSOURI St. Louis ESC Sales & Leasing 314-997-1515 FAR EAST Hong Kong Equipment 5-453870 FRANCE Paris Gepsi 1-554-9742 GERMANY Munich Technitron 49(89)692-4141 Distributor inquiries welcome! Circle 148 on inquiry card. INDIANA So. Bend Audio Specialists 219-234-5001 NEW MEXICO Albuquerque Qualtech 505-255-6100 THE NETHERLANDS Compudata Benelux B.V. 73-21 5700 BYTE April 1981 225 sion programs have been prepared to demonstrate two different uses of data compression. The compression pro- gram, COMPl, demonstrates the basic concept. (See listing 1.) Characters are entered from the keyboard and the output of the program is a serial bit stream that could be sent to a cassette for storage of the compressed data. Such a scheme could result in reduced writing time and faster access to the data. The tradeoff involved is the usual one in many data-processing situations; namely, storage space saved versus computer time used to encode and decode the data. The amount of compression is highly dependent upon the data and its characteristics. Since COMPl is for demonstration purposes only, the program is simplified somewhat by storing the serial data 1 bit per byte of memory. This is just a convenience that simplifies the expansion program, EXPl. (See listing 2.) If the data were actually being sent to a serial output port, only minor changes in the code would be required. The second compression program, COMP2, uses the same basic compression method as COMPl. (See listing 3.) However, the resulting serial bit stream is broken into 8-bit bytes for use by a parallel storage medium such as programmable memory. This provides maximum com- pression in a fixed-word-length computer. The program H/Zn89, S-100 CP/M*, Data Base, & Peripherals Small Systems Consulting Customized Data Base Design ST506 5MB n Winchester, 2 Drive Controller, CP/M S2500 Additional Drives SI 400 NEW IDS Tiger 560 Printer, 14.5", Hi-Res Matrix with Plot and Word Processing firmware . SI 595 The MDBS Networking Data Base System with Query, Recovery, Logging, Restructure, more SI 400 1 6KB RAM Expansion Board, CP/M 2.2, and HDOS- CP/M address conversion ROM S 280 UDST03LP Modem, 300 baud, direct connect, phone powered, answer/originate S 185 (103J-LP) with auto answer S 225 Magic Wand** text editor and formatter S 275 • Stop by our booth attheWestCoast Computer Faire!* Add 1 % shipping & insurance. California residents add 6% sales tax. iRRCO DEVELOPMENT CORPORATION 1 445 Ko/I Circle, Suite 111, San Jose, CA 95 1 1 2 • |408| 947- 1 1 1 SOURCE: TCE421 "Trademark of Digital Research * "Trademark of Small Business Applications. Inc EXP2 expands the compressed text created by COMP2. (See listing 4.) The description of the compression and ex- pansion programs emphasizes the table structure, since both programs use tables to facilitate changing codes. COMPl Description This program takes characters entered via the keyboard, checks for a legal character, finds the Huffman code corresponding to the entered character, and stores the bit stream sequentially in memory. Each bit is stored in the lowest-order bit of a byte for demonstration conve- nience and for interfacing with EXPl. The first two words of the output buffer contain a count of the number of bits that are stored in the remainder of the buffer. This infor- mation is used by EXPl to stop the decoding process on the bit stream. The input need not come from the keyboard and could be from another buffer, simply by changing a few lines of code related to the input function. The heart of the program's operation is the table lookup and the shifting function. Based upon a letter's ASCII code, an index is computed that is then added to the base address of the encoding table. This table has the following format: two 8-bit words are required for each letter to be encoded; the low-order 4 bits of the first word in memory contain a count of the number of bits required to encode the letter. The remaining 12 bits, 8 in the second byte followed by 4 in the top half of the first byte, are used to store the compressed code. (Note that the word order in the source statement and in memory is reversed because of the assembler's treatment of the DW (Define Word) instruction. The code is stored left- justified in the 12-bit area. This format makes processing simple when the two words are loaded into the D and E register pair for shifting. With the compressing code located, it is serialized by shifting left according to the count in the 4-bit part of the table. The DAD (add register pair to H and L) instruction effectively shifts the DE register pair's high-order bit into the carry register. As each bit is shifted out, the total bit count in the buffer is updated. The processing of the in- put stream continues until a period is detected, and con- trol returns to the system monitor. It should be noted that the only characters that are en- coded are the twenty-six alphabetic letters. Any other characters (including blanks) are ignored. In a non- demonstration environment, spaces, punctuation, and other symbols would have to be included; this would re- quire enlarging the lookup table to include the represen- tation of the new symbols. EXPl Description The expansion program, EXPl, operates on the bit stream prepared by COMPl. (See listing 2.) It expects this data to be in the buffer defined by COMPl, with the bit count in the first two words and the data bit in the lowest bit of each byte. This program is also table-driven; but the table is more complex than the encoding table and the processing is more involved. Basically, the program searches a binary tree to decode the bit stream. The binary tree shown in figure 2 is converted to a table. The program then steps through the table, selecting the ap- propriate branch in the tree structure depending upon the value of each bit in the data stream. The data in the table Text continued on page 246 226 April 1981 © BYTE Publications Inc Circle 149 on inquiry card. Who will be first with the avionics of the 21st century? It could be you and Hughes Radar Systems. We pioneered pulse Doppler radar and built the first operational airborne programmable signal processor. Today, three out of the four front-line U.S. tactical aircraft have Hughes radars. We're leaders in synthetic aperture radar, in-weather reconnaissance and strike radar, high order language, an- tenna arrays and holographic displays. We're even building the rendezvous radar for the Space Shuttle. And with computer-aided design, manufacturing, and testing of intelli- gent radar devices, the future is at Hughes. In fact, Hughes is one of the nation's largest employers of electronic engi- neers and a major employer in virtually every other scientific, computer and technical discipline — with 1,500 pro- jects and a backlog of over $5 billion. Yet we're decentralized to give you the kinds of environments that stimulate innovation and promote recognition of your work. Who will be first with the avionics of the future? It could be you and Hughes. At Hughes Radar Systems, we'll introduce you to people, ideas and jobs that could change your world. And maybe ours. It could be you and Hughes Radar Systems. Call (213) 647-4900, collect, or send resume to: Engineering Employment Hughes Radar Systems P.O. Box 92426 Dept. B-4 Los Angeles, CA 90009 Current openings: Software Design/Analysis Software Test Engineering Systems Integration & Test Computer-Aided Design & Manufacturing RF/Microwave Design Digital Circuits Design & Test Radar Systems Design Large Scale Integration Design, Development & Test Production Process Engineering Microprocessor Development/ Applications Antenna Systems Design & Test Reliability Engineering Production Test Engineering Industrial Engineering HUGHES AIRCRAFT COMPANY RADAR SYSTEMS Proof of U.S. Citizenship Required Equal Opportunity Employer Listing 1: COMF1 text-compression routine. This routine takes only alphabetic text entered from the keyboard and converts it to the Huffman code given by the tree in figure 2. The Huffman code is stored 1 bit per byte. The routine is written in 8080 machine code. 7 500 ?5oo ->500 9500 9500 ?500 7500 ?5no 9500 2500 7500 31 00 00 7503 21 00 no ■7506 ?? 00 41 7509 21 02 41 250C 22 8C 25 ?50F DB 08 7511 OF 251? Da OF ?5 2515 DB 0\ 2517 FE 2E 2519 CA OC 00 251C CD 00 C5 251F E6 7F 2521 D6 41 2523 DA OF 25 2526 FE l.A 2528 D2 OF 25 252B 87 252C 4F 252D 06 00 252F 21 58 2.5 2532 09 9 53 3 5E 2 534 73 ■?535 56 7536 7B 2537 E6 OF 7539 47 7 53A EB 753B AF 253C 29 253D 17 253E E6 01 2560 E5 2541 2A 8C 25 2544 77 2545 23 7546 22 8C 25 2.549 2 A 00 41 754C 23 754D 22 00 41 2550 El 2551 05 2552 C2 3B 25 2 .5*5 C3 OF 25 7558 7558 2558 2558 04 FO 255A 06 70 25 SC 05 40 25^ 05 D8 7560 03 80 756? 05 48 2564 05 08 2566 04 50 2568 04 AO 756A 09 DO 256C 89 Dl 256E 05 78 0001 0002 0003 0004 0005 0006 0007 0010 0011 0012 0020 0021 0077 0023 0024 0040 0041 0042 0043 0060 0070 0073 0075 0080 0082 0084 0086 0090 0100 0110 0120 0130 0140 0150 0160 0170 0180 0185 0187 0190 0192 0200 022.0 0225 0226 0228 0229 0231 0232 0235 0236 0238 0260 0270 0300 0305 0306 0307 0310 0320 0330 0340 0350 0360 0370 0380 0390 0400 0410 0420 *THIS ROUTINE TAKES TEXT, (LETTERS ONLY) *AND COMPRESSES THEM USING HUFFMAN CODING. FOR *TEST PURPOSES THERE IS ONE BIT PER BYTE IN THE *DATA BUFFER. THE FIRST TWO BYTES IN THE DATA BUFFER *ARE THE BIT COUNT. ENCODED DATA IS STORED IN DBUF AS 1 BIT *PER BYTE FOR TEST PURPOSES. NORMALLY DATA WOULD BE PACKED *OR OUTPUTTED SERIALLY. ECHO: EQU 0C500H ;OUTPUT DRIVER SP: ECU 6 MON: ECU OCH LXI SP,0 LXI H,0 SHLD DBUF •.MONITOR RETURN INCH: ;END OF TEXT ;NO MORE ; CLEAR PARITY ; COMPUTE INDEX A'+l COMPRESSED BIT COUNT LXI H.DBUF+2 SHLD DADD ;NEXT BIT LOCATION IN 8 RRC JC INCH IN 10 CPI ' .' JZ MON C-\LL ECHO .AN I 07FH SUI 'A' JC INCH CPI 'Z'-' JNC INCH .ADD A MOV C,A MVI B,0 LXI H,TABL DAD B MOV E,M INX H MOV D,M MOV A,E .AN I OFH MOV B,A XCHG XRA A DAD H RAL AN I 1 PUSH H LHLD DADD MOV M,A INX H SHLD DADD LHLD DBUF INX H SHLD DBUF POP H RCR B JNZ NEXT JMP INCH ♦ENCODE TABLE FORMAT- LOW ORDER 4 BITS ARE NUMBER OF BITS *IN ENCODED CHARACTER. REMAINING 12 BITS .ARE FOR CODE. *CODE IS LEFT JUSTIFIED. E.G., AN M IS 00011 ; MULT I PLY BY 2 ; INDEX ;GET ENCODE VALUE GET BIT COUNT MASK COUNT KEEP COUNT NEXT: SHIFT OUT BIT MSB FIRST SETUP OUTPUT BIT ; STORE BIT .UPDATE BIT COUNT [REDUCE COUNT STREAM TABL: DW 0F004H DW 7006H DW 4005H DW 0DR05H DW 8003H DW 4805H DW 805H DW 5004H DW 0A004H DW 0D009H DW 0D189H DW 7805H 228 April 1981 © BYTE Publications Inc Listing 1 continued on page 230 Circle 150 on inquiry card. > COMPUTERS-TERMINALS-MODEMS! MODEMS AND COUPLERS Connect your Apple, TRS-80 or any other computer or terminal to the phone lines! Penril Penril 300/1200 Penril 300/1200— Bell 212A style $799 Bell 21 2A style. 1 200 baud and 300 baud. Manual origi- nate, auto-answer. Full duplex. RS232. Direct connect to phone lines via RJ11C standard extension phone voice jack. 1 year warranty. U.S. Robotics USR-330A Bell 103/113 style USR-330D Bell 103/113 style USR-330D $339 Bell 103/113 style. 330 baud. Manual originate, auto- answer. Half/full duplex. RS232. 1 year warranty. Direct connect to phone lines via RJ11C standard extension phone voice jack. USR-330A $399 Same as USR-330D but includes auto-dial capability. U.S. Robotics The Phone Link Acoustic Modem Bell 103/113 style $179 300 baud. Sleek, low profile. Originate and answer cap- ability. Half/full duplex. Self-test. RS232. Light displays for On, Carrier, Test, Send Data, Receive Data. 15 oz. Perkin-Elmer Corporation Bantam 550B .... $694 1 Compact. Silent. Upper/lower case. 80th col. wrap-around. Bell. Integrated numeric pad. _ Printer port. Transparent I mode. Editing features. Tabbing. Bantam 550E...$755| Same as 550B plus separate numeric key- pad and cursor direction I keys. Bantam 550S $879 Same as 550E plus block mode. 8 function keys, and protected fields, reverse video fields, half intensity fields, blinking fields. 550 Options 20mA Current Loop Interface $70 Non-Glare Screen $25 2nd page of memory (550S only).. $100 Digital Equipment Corporation DECVT100 . DEC VT100... $1668 Detachable keyboard. Separate numeric keypad with function keys. Business forms character set. Reverse video. Selectable double-size characters. Bidirectional smooth-scrolling. 80 cols or 132 cols. Split screen. Set- table tabs. Line drawing graphic characters. Status line. Key-Click. HARDCOPY TERMINALS Teletype Model 43 CRT's Perkin-Elmer Corporation Superowl 1251 Perkin-Elmer Superowl 1251 $1564 Intelligent, editing CRT. Detachable keyboard. 32 fully programmable function keys. Intelligent printer part. Business forms character set. Block mode. Protected fields. Blinking fields. Numeric fields. Reverse video. Half intensity. Polling. Down line loading of options. Re- mote control of all options by host computer. Settable tabs. Status line. Separate numeric keypad. Transpar- ent mode. Teletype Corporation Teletype Model 43 KSR with RS232 and Connector Cable $999 30CPS. Dot matrix. 132 cols. True descenders on lower case. Excellent print quality for dot matrix printer. Pin feed. NEC Corporation NEC Spinwriter 5510 & 5520 5520 KSR Spinwriter $3088 55 CPS. Impact printer. Selectric print quality. Change- able print fonts. 110, 300 and 1 200 baud data rate. Nu- meric keypad. Friction and tractor feed. 5510 Spinwriter $2754 55 CPS. Impact printer. Selectric print quality. Change- able print fonts. 110, 300 and 1 200 baud data rate. Fric- tion and tractor feed. Digital Equipment Corporation DECLA120... $2388 1 80 CPS. Dot matrix. Upper/lower case. 1 K buffer. De- signed for 1200 baud communications. 30 character answerback message. Adjustable line spacing. Adjus- table character sizes including double sized characters. Settable horizontal and vertical tabs. Top-of-form capa- bility. RS232. Perkin-Elmer Corporation Pussycat 650/655 CRT Screen Printer 650/655 Pussycat CRT Screen Printer . $899 100 CPS. Extremely compact and quiet. 110 to 9600 baud rate. 2K buffer. Ideal for producing rapid, reliable hardcopy of your CRT screen display. Can be added to any CRT with our interface option. Digital Equipment Corp. DECLA34DA... $939 30 CPS. Dot matrix. Upper/lower case. 4 character sizes. Up to 217 cols per line. 6 lines per inch settings. Friction feed. Settable tabs. RS232. DECLA34AA $1095 30 CPS. Dot matrix. Upper/lower case. 8 character sizes including double size characters. 6 lines per inch settings. Up to 21 7 cols per line. Friction feed. Settable horizontal and vertical tabs. Top-of-form capability. Options for LA34AA and LA34DA Tractor Feed Mechanism $114 Numeric Keypad w/ Function Keys . . $69 Pedestal $100 Paper Out Sensor $25 APL Capability with APL Keycaps .. $499 2K Buffer with Text Editor and 1200 Baud Communications Capability $499 m Leasing rates and lease/purchase plan information is available on request. All equipment is shipped with a 10 day money back guarantee. We offer full service, on site maintenance plans on all equipment. All equipment in stock. SI3liiP?f™l"T"II™**2t SALES GENERAL OFFICES SERVICE C3ISJ 34B-5B50 C3I2) 346-5651 C3I2) 733-0497 listing l con tinued 2570 05 18 2572 04 CO 2574 04 EO 2576 06 D4 2578 4A Dl 257A 04 BO 257C 04 60 257E 03 20 2 580 05 10 2582 07 D2 2584 06 74 2586 89 DO 258* 05 00 2 58 A 0A Dl 258C 00 00 258E 4100 0430 DW 1805H M 0440 DW 0C004H N 0450 DW OE004H 0455 DW 0D406H P 0460 DW 0D14AH 0470 DW 0B004H R 0480 DW 6004H S 0490 DW 2003H T 0500 DW 1005H U 0510 DW 0D207H V 0520 DW 7406H W 0530 DW 0D089H X 0540 DW 5H Y 0550 DW 0D10AH Z 0600 DADD: DW N 0605 ORG 4100H 0610 DBUF: DS 1000 NEXT BIT LOCATION Listing 2: EXP1 text-expansion routine. This routine takes the output of COMP1, information expressed in a Huffman code, and decodes it using the binary tree of figure 2. The decoded character is displayed via a user-supplied subroutine named DISP. The routine is written in 8080 machine code. 3000 3000 3000 3000 3000 3000 3000 3000 3000 3000 3000 01 00 00 3003 21 02 41 3006 22 97 30 3009 21 00 41 300C 4E 3 OOP 23 300E 46 300F C5 7010 21 4B 30 701? E5 3014 3 A 97 30 3017 4E 3019 23 3019 06 00 301B 3? 97 30 301E El 301F 09 30?0 7E 30?1 17 3022 DA 32 30 3025 IF 3026 5F 3037 16 00 3039 19 3 03 a CI 303B CD 44 30 303E C5 302F C3 13 30 3032 IF 3033 E6 7F 3035 5F 3036 16 00 3038 19 3039 7E 303A CD 00 C5 30 3D ri 3 03E CD 44 30 3041 C3 OF 30 0000 0001 0002 0003 0004 0005 0006 0007 0008 0009 0010 0020 0030 0040 0050 0060 0070 0080 0090 0100 0110 0120 0130 0140 0150 01*0 0170 0180 0190 0200 0205 0210 0220 0230 0240 0250 0270 0280 0290 0294 0296 0297 0298 0299 0305 0310 0320 0330 *THIS PROGRAM ACCEPTS DATA PREPARED BY THE DATA COMPRESSION ♦(HUFFMAN CODE) PROGRAM. THE DATA BUFFER HAS THE BIT COUNT *IN THE FIRST TWO BYTES. THE PROGRAM RUNS UNTIL ALL BITS *HAVE BEEN PROCESSED. THE PROCESSING CONSISTS OF ADDING A *DATA BIT TO THE TABLE ENTRY POINT, GETTING AN INCREMENT *VHICH POINTS TO THE NEXT 0-1 PAIR AND CONTINUING UNTIL *A TAG IS FOUND IN BIT 7. THIS SIGNIFIES THAT THE NEXT *TABLE ENTRY IS THE DESIRED CHARACTER. IN A NON-TEST MODE *DATA WOULD BE EITHER PACKED IN 8 BIT BYTES OR ARRIVING *VIA A SERIAL PORT. EXP: NEXT: OUTCH: LXI SP,0 LXI H.DBUF+2 SHLD DADD LXI H.DBUF MOV C,M INX H MOV B,M PUSH B LXI H.XTAB PUSH H LHLD DADD MOV C,M INX H MVI B,0 SHLD DADD POP H DAD B MOV A,M RAL JC OUTCH RAR MOV E,A MVI D,0 DAD D POP B CALL DECB PUSH B JMP NEXT RAR AN I 7FH MOV E,A MVI D,0 DAD D MOV A,M CALL DISP POP B CALL DECB JMP EXP ; FIRST BIT ;NEXT DATA ADDRESS ;BIT COUNT ; DECODE TABLE ;DATA VALUE ; TABLE + DATA BIT GET POINTER ;TABLE+DATA BIT + POINTER : REDUCE BIT COUNT ; REMOVE TAG ;GET DECODED CHARACTER Listing 2 continued on page 232 230 April 1981 © BYTE Publications Inc The Text Solution for APPLE II® Now APPLE II® Owners Can Solve Text Problems With VIDEOTERM 80 Column by 24 Line Video Display Utilizing 7 X 9 Dot Character Matrix Perhaps the most annoying shortcoming of the Apple II'*' is its limitation of displaying only 40 columns by 24 lines of text, all in uppercase. At last, Apple II® owners have a reliable, trouble-free answer to their text display problem. VIDEOTERM generates a full 80 columns by 24 lines of text, in upper and lower case. Twice the number of characters as the standard Apple II® display. And by utilizing a 7 by 9 character matrix, lower case letters have true descenders. But this is only the start. VIDEOTERM, MANUAL, SWITCHPLATE VIDEOTERM BASICS Other Boards i " h n ' ( ) * + , - . / 0123456789: ;(»>? t A | C D E F G H I J K L M N P 6 R S T U V H X Y Z [ \ ] A . y z ( ! ) 7X12 MATRIX 18X80 OPTIONAL I'MII ' t }*♦■- ./ 1123456 789 i j < = >? CABCDEFSHIJKLHNO POBSTUVUXYZI\]t_ 'jbcdefghijlclino pgr5ti/vwxyz(l}"| 7X9 MATRIX 24X80 STANDARD VIDEOTERM lists BASIC programs, both Integer and Applesoft, using the entire 80 columns. Without splitting keywords. Full editing capabilities are offered using the ESCape key sequences for cursor movement. With provision for stop/start text scrolling utilizing the standard Control-S entry. And simultaneous on-screen display of text being printed. Installation of VIDEOTERM in slot 3 provides Pascal immediate control of the display since Pascal recognizes the board as a standard video display terminal and treats it as such. No changes are needed to Pascal's MISC. INFO or GOTOXY files, although customization directions are provided. All cursor control characters are identical to standard Pascal defaults. The new Microsoft Softcard' is supported. So is the popular D. C. Hayes Micro- modem II' , utilizing customized PROM firmware available from VIDEX. The power- ful EasyWriter" Professional Word Processing System and other word processors are now compatible with VIDEOTERM. Or use the Mountain Hardware ROMWriter* (or other PROM programmer) lo generate your own custom character sets. Natural- ly, VIDEOTERM conforms to all Apple OEM guidelines, assurance that you will have no conflicts with current or future Apple II' expansion boards. VIDEOTERM's on-board asynchronous crystal clock ensures flicker-free character display. Only the size of the Pascal Language card, VIDEOTERM utilizes CMOS and low power con- sumption ICs, ensuring cool, reliable operation. All ICs are fully socketed for easy maintenance. Add to that 2K of on-board RAM, 50 or 60 Hz operation, and provision of power and input connectors for a light pen. Problems are designed out, not in. The entire display may be altered to inverse video, displaying black characters on a white field. PROMs containing alternate character sets and graphic symbols are available from Videx. A switchplate option allows you to use the same video monitor for either the VIDEOTERM or the standard Apple II" display, instantly changing displays by flipping a single toggle switch. The switchplate assembly inserts into one of the rear cut-outs in the Apple II' case so that the toggle switch is readily accessible. And the Videx KEYBOARD ENHANCER can be installed, allowing upper and lower case character entry directly from your Apple II' keyboard. Firmware 1K of on-board ROM firmware controls all operation of the VIDEOTERM. No machine language patches are needed for normal VIDEOTERM use. Firmware Version 2.0 Characters 7x9 matrix Display Options 7x12 matrix option; Alternate user definable character set option; Inverse video option. Want to know more? Conlact your local Apple dealer today for a demonstration. VIDEOTERM is available through your local dealer or direct from Videx in Corvallis, Oregon. Or send for the VIDEOTERM Owners Reference Manual and deduct the amount if you decide to purchase. Upgrade your Apple II' to full terminal capabilities for half the cost of a terminal. VIDEOTERM. At last. Advanced Hardware Design Available Options 24 x 80 (full descenders) 18 x 80 (7 x 12 matrix with full descenders) Apple II* is a trademark of Apple Computer Inc. ROMWnter* is a trademark ol Mountain Hardware Inc. Micromodem II* 15 a trademark ot D C. Hayes Associates Inc. Softcard' is a trademark ol Microsofl EasyWriter" is a trademark ol Information Unlimited Software Inc PRICE: • VIDEOTERM includes manual $345 • SWITCHPLATE $ 19 • MANUAL refund with purchase .... $ 19 • 7x12CHARACTERSET $ 39 • MICROMODEM FIRMWARE $ 25 APPLE II® OWNERS! introducing the KEYBOARD & DISPLAY ENHANCER ■ PUT THE SHIFT AND SHIFT LOCK BACK WHERE IT BELONGS ■ SEE REAL UPPER AND lower CASE ON THE SCREEN •ACCESS ALL YOUR KEYBOARD ASCII CHARACTERS Videx has the perfect companion for your word processor software: the KEYBOARD AND DISPLAY ENHANCER Install the enhancer in your APPLE II and be typing in lower case just like a typewriter. If you want an upper case character, use the SHIFT key or the CTRL key for shift lock. Not only that, but you see upper and lower case on the screen as you type. Perfectly compatible with Apple Writer and other word processors like, for example. Super-Text. If you want to program in BASIC, just put it back into the alpha lock mode; and you have the original keyboard back with a few im- provements. Now you can enter those elusive 9 characters directly from the keyboard, or re- quire the Control key to be pressed with the RESET to prevent accidental resets. KEYBOARD AND DISPLAY ENHANCER is recommended for use with all revisions of the APPLE II. It includes 6 ICs. and EPROM and dip-switches mounted on a PC board, and a jumper cable. Easy installation, meaning no soldering or cutting traces. Alter- nate default modes are dip-switch selectable. You can even remap the keyboard, selecting an alternate character set. for custom applications. PRICE • KDE-700 (REV. 7 or greater) $129. » KDE-000 (REV. 6 or less) $129. Apple II'" is a trademark of Apple Computer. Inc. ffl B VIDEX 897 N.W. Grant Avenue Corvallis, Oregon 97330 Phone (503) 7580521 Circle 151 on inquiry card. BYTE April 1981 231 Listing 2 3044 3045 3046 3047 304A 304B 3 04B 304B 3 04B 3 04B 304B 306B 3 04C 304P 304E 3 04F 3050 3051 3052 3053 3054 3055 3056 3057 3058 3059 305A 305B 305C 305P 305E 305F 3060 3061 3 062 3 063 3 064 3065 3066 3067 3068 3069 3 06A 306B 306C 306D 3 06E 306F 3070 3071 3072 3073 3074 3075 3076 3077 3078 3079 307A 307B 307C 307D 307E 307F 3080 3081 3082 ■'083 ''084 3085 3086 3087 continued: OB 79 BO CA OC 00 C9 2A 01 02 08 82 02 45 82 82 49 52 06 01 82 82 4F 41 82 02 4E 03 81 44 03 81 50 03 81 56 02 05 82 82 4A 58 03 81 4B 82 82 5A 51 02 OE 03 81 54 02 05 82 82 59 47 82 82 55 4D 02 08 03 81 0340 0350 0360 0365 03 70 4000 4010 4020 4030 4040 4050 5000 5010 5020 5030 5040 5050 5060 5070 5080 5090 5100 5102 5104 5106 5108 5110 5120 5130 5140 5150 5160 5170 5180 5190 5200 5210 5220 5230 5240 5250 5260 5270 5280 5290 5300 5310 5320 533 5340 5350 5360 5370 5380 5390 5400 5410 5420 5430 5440 5450 5460 5470 5480 5490 5500 5510 5520 5530 5540 5550 5560 DECB: DCX B MOV A,C ORA B JZ MON RET *THE DECODE TABLE HAS *THE TABLE VALUE IS T *NEXT 0-1 PAIR AS THE *THE TABLE VALUE JUST *SET IN BIT 7, IN ADD *THAT THE NEXT VALUE XTAB: ; REDUCE BIT COUNT THE FOLLOWING FORMAT: HE INCREMENT NECESSARY TO GET TO THE PROGRAM STEPS THROUGH THE DATA. PRECEEDING A CHARACTER HAS A TAG IT ION TO THE INCREMENT, TO INDICATE IA A CHARACTER. DB 42 DB 1 DB 2 DB 8 DB 130 DB 2 DB 'E' DB 130 DB 130 DB •I' DB 'R' DB 6 DB 1 DB 130 DB 130 DB '0' DB •A' DB 130 DB 2 DB i N i DB T DB 129 DB •D' DB 3 DB 129 DB ipi DB 3 DB 129 DB 'V DB 2 DB 5 DB 130 DB 130 DB •J' DB 'X' DB 3 DB 129 DB 'K' DB 130 DB 130 DB 'Z' DB • Ql DB 2 DB 14 DB 3 DB 129 DB i f i DB 2 DB 5 DB 130 DB 130 DB •Y« DB 'G' DB 130 DB 130 DB >U' DB 'M' DB 2 DB 8 DB 3 DB 129 1 1 2 3 1 4 5 1 6 7 8 1 9 10 11 12 1 13 14 1 15 16 17 18 1 19 20 21 1 22 23 24 1 25 26 27 1 28 29 30 1 31 32 1 3^ 34 35 36 1 37 38 39 1 40 41 42 43 1 44 45 1 46 47 48 1 49 50 1 51 52 53 54 1 55 56 57 58 1 59 60 1 Listing 2 continued on page 234 232 April 1981 © BYTE Publications Inc DIGITAL HARMONY A new synthesis of sight and sound Digital Harmony by John Whitney Digital Harmony lays the foundation for the whole new field of audio-visual art made possible by microcom- puters. John Whitney, a pioneer of the special effects technology used in STAR WARS and 2001: A SPACE ODYSSEY, explains the special union of computer graphics and music. His computer-generated visual art graphically depicts the laws of harmonic motion com- mon to all music. Digital Harmony includes a complete description of Whitney's computer, peripherals, and film techniques. Col- orful illustrations are included, as well as the program listings that generated them. The descriptions are sufficient for anyone to begin to explore this new territory as a composer and computer experimenter — transforming the small computer into an ideal instrument for creating compositions in aural and visual art. 'John Whitney is on the Faculty in the Department of Art at the University of California, Los Angeles. ISBN 07-07001 5-X $21.95 Please remit in U.S. funds or draw on a U.S. Bank Please send □ copies of Digital Harmony Available Now Toll Free # 1-800-258-5420 Name Title Company Street City State/Province Code □ Check enclosed in the amount of $ D Bill Visa □ Bill Master Charge Card No Exp. Date. Add 75c per book to cover postage and handling. H V I K 70 Main Street R'l'IVI Peterborough, New Hampshire 03458 Circle 152 on inquiry card. BYTE April 1981 233 Listing 2 continued 3088 48 3089 82 308A 82 308B 43 308C 46 308D 82 308E 02 3 08F 53 3090 03 3091 81 3092 4C 3093 82 3094 82 3095 42 *09*5 57 ''097 02 41 309"> 4100 44E8 44E8 44E8 5570 DB •H' ; 61 5580 DB 130 62 5590 DB 130 63 1 5600 DB i C i 64 5610 DB • pi 65 5620 PB 130 66 5630 DB 2 67 1 5640 DB ■S' 68 5650 DB 3 69 5660 DB 129 70 1 5670 DB 'L' 71 5680 DB 130 72 5690 DB 130 73 1 5700 DB ■B' 74 5710 DB . W i ,75 5720 DADD: DW DBUF+2 NEXT DATA ADDRESS 5909 ORC ■ 4100H 6000 DBUF: DS 1000 9000 DISP: EQL 0C500H DISPLAY A CHARACTER 9010 MON ECU 0OOCH MONITOR RETURN 9020 SP: ECU Listing 3: COMP2 text-compression routine. This routine is identical to COMP1 (listing 1) except that the Huffman code information is packed and stored 8 bits to the byte. The routine is written in 8080 machine code. 2600 0001 ♦THIS ! ROUTINE TAKES TEXT (LETTERS ONLY) 2600 0002 *AND COMPRESSES THEM USING HUFFMAN CODING. 2600 0004 *THE FIRST TWO BYTES IN THE DATA BUFFER 2600 0005 *ARE THE BIT COUNT. ENCODED DATA IS STORED IN DBUF 2600 0006 *1N A PACKED FORM, 8 BITS TO THE BYTE. 2600 0010 ECHO: ECU 0C500H ; OUTPUT DRIVER 2600 0011 SP: EQU 6 2 600 0012 MON: ECU OCH • MONITOR RETURN 2600 31 00 00 0020 LXI SP,0 2603 21 00 00 0021 LXI H,0 2606 22 00 41 0022 SHLD DBUF •.COMPRESSED BIT COUNT 2609 21 02 41 0023 LXI H, DBUF+2 260C 22 BA 26 0024 SHLD DADD ;NEXT BIT. LOCATION 260F AF 0025 XRA A 2610 32 BC 26 0026 STA POS 2613 DB 08 0040 INCH: IN 8 ; INPUT CODE 2615 OF 0041 RRC 2616 DA 13 26 0042 JC INCH 2619 DB OA 0043 IN 10 261B FE 2E 0045 CPI '.• ;END OF TEXT 261D C2 37 26 0047 JNZ PROS 2620 2A BA 26 0050 LHLD DADD ; CLEAN UP PARTIAL BYTE 2623 3A BC 26 0052 LDA POS 2626 47 0054 MOV B,A ; COMPUTE SHIFT COUNT 2627 3E 08 0056 MVI A, 8 2629 90 0058 SUB B 262A E6 07 0060 ANI 7 262C 47 0062 MOV B,A ;KEEP SHIFT COUNT 262D 7E 0064 MOV A,M ;GET PACKED BYTE 262E CA OC 00 0066 SHFT: JZ MON ; FINISHED 2631 17 0068 RAL 2632 05 0070 DCR B 2633 77 0071 MOV M,A •.REPLACE PACKED BYTE 2634 C3 2E 26 0072 JMP SHFT 2637 CD 00 C5 0073 PROS: CALL ECHO 263A E6 7F 0075 ANI 07FH •.CLEAR PARITY 263C D6 41 0080 SUI 'A' ;COMPUTE INDEX 263E DA 13 26 0082 JC INCH 2641 FE 1A 0084 CPI 'Z'-'A +1 2643 D2 13 26 0086 JNC INCH 2646 87 0090 ADD A ; MULTIPLY BY 2 2647 4F 0100 MOV C,A 2648 06 00 0110 MVI B,0 264A 21 86 26 0120 LXI H.TABL 264D 09 0130 DAD B ; INDEX Listing 3 continued on page 236 234 April 1981 © BYTE Publications Inc THE ADVANTAGES OF THE FUNCTIONAL GROUP Diversity of projects. Varied technical challenge. Involvement from con- cept through implementation. Broadinteraction and cooperation between software and hardware. We've got it all at Harris Composition Systems in Mel- bourne, Florida. We're pioneers in word processing. And the world's first and leading supplier of total word processing systems for use in the newspaper industry. And we're now extending that "system-oriented" ap- proach into the office systems field— integrating data proc- essing, word processing, electronic mail, advanced communications and net- working. With an ambitious program representing the largest investment Harris Corporation has ever made to develop a new product. That means the opportu- nity for personal participation and immediate contribution— across the board— in both newspaper word processing and office systems. For experienced pro- fessionals with expertise in □ Real Time Software and Hardware/Firmware Devel- opment □ Digital Design □ Analog Design □ Applica- tions Programming. All supported by a billion dollar, Fortune 500 corpora- tion. All in a modern, stimu- lating work environment. All in beautiful, affordable Melbourne, Florida— on the shores of the deep blue Atlantic. Send your resume and salary history to: Daphne Cumberland, Composition Systems Division, Dept. BT, P.O. Box 2080, Melbourne, Florida 32901. Or call COL- LECT (305) 242-5321, in Florida. Outside Florida call 1-800-327-1493. Share the advantages with ; COMMUNICATION AND INFORMATION PROCESSING An Equal Opportunity Employer M/F/V/H. Listing 3 continued: 264E 5E 264F 23 2650 56 2651 7B 2652 E6 OF 2654 47 2655 EB 2656 AF 2657 29 2658 17 2659 E6 01 265B E5 265C 2A BA 26 265F 57 2660 3A BC 26 2663 5F 2664 7E 2665 17 2666 B2 2667 77 2668 1C 2669 7B 266A FE 08 266C C2 74 26 266F AF 2670 23 2671 22 BA 26 2674 32 BC 26 2677 2A 00 41 267A 23 267B 22 00 41 267E El 267F 05 2680 C2 56 26 2683 C3 13 26 2686 2686 2686 2 686 04 FO 2688 06 70 268A 05 40 2 68C 05 D8 268E 03 80 2690 05 48 2692 05 08 2 694 04 50 2696 04 AO 2698 09 DO 269A 89 Dl 269C 05 78 269E 05 18 2 6A0 04 CO 26A2 04 EO 26A4 06 D4 2 6A6 4A Dl 2 6A8 04 BO 26AA 04 60 26AC 03 20 26AE 05 10 26B0 07 D2 26B2 06 74 26B4 89 DO 26B6 05 00 26B8 OA Dl 26BA 00 00 26BC 26BD 4100 0140 MOV E,M GET ENCODE VALUE 0150 INX H 0160 MOV D,M 0170 MOV A,E GET BIT COUNT 0180 AN I OFH MASK COUNT 0185 MOV B,A KEEP COUNT 0187 XCHG 0190 NEXT: XRA A 0192 DAD H SHIFT OUT BIT STREAM 0200 RAL ,MSB FIRST 0220 AN I 1 ; SETUP OUTPUT BIT 0225 PUSH H 0226 LHLD DADD 0228 MOV D,A LDA POS 0229 0231 MOV E,A .KEEP CURRENT POSITION 0233 MOV A,M ;GET OLD PACKED DATA 0235 RAL .MAKE ROOM 0237 ORA D .PACK 0239 MOV M,A .PUT IT AWAY 0240 INR E .UPDATE POSITION 0242 MOV A,E 0244 CPI 8 ;FULL BYTE? 0246 JNZ STOR 0248 XRA A [INITIALIZE POSITION 0250 INX H [UPDATE DADD 0252 SHLD DADD 0258 STOR: STA POS 0260 LHLD DBUF 02 62 INX H jUPDATE BIT COUNT 0264 SHLD DBUF 0266 POP H 0268 DCR B .REDUCE COUNT 0270 JNZ NEXT 0300 JMP INCH 0305 ♦ENCODE TABLE FORMAT- LOW ORDER 4 BITS 0306 *IN ENCODED CHARACTER. REMAINING 12 BITS 0307 *CODE IS LEFT JUSTIFIED. E.G., AN M IS 0310 TABL: DW 0F004H ;A 0320 DW 7006H ;B 0330 DW 4005H ,C 0340 DW 0D805H ;o 0350 DW 8003H ;E 0360 DW 4805H ;F 0370 DW 805H ;G 03 80 DW 5004H ;H 0390 DW OA004H ;I 0400 DW 0D009H ;J 0410 DW 0D189H ;K 0420 DW 7805H ;L 043 DW 1805H ;M 0440 DW 0C004H ;N 0450 DW OE004H ;0 0455 DW 0D406H ,P 0460 DW 0D14AH ;Q 0470 DW 0B004H R 0480 DW 6004H ,S 0490 DW 2003H J 0500 DW 1005H U 0510 DW 0D207H V 0520 DW 7406H w 0530 DW 0D089H X 0540 DW 5H Y 0550 DW 0D10AH Z 0600 DADD: DW ;NEXT BIT LOCATION 0603 POS: DS 1 .BIT POSITION 0605 ORG 4100H 0610 DBUF: DS 1000 ARE NUMBER OF BITS ARE FOR CODE. 236 April 1981 © BYTE Publications Inc IF YOU CAN VAIT A MINUTE, WE CAN S/y E YOU H J iii With the Storwriter™ Daisy Wheel 25 cps printer from C. Iron. A business letter, written on a 45 cps word-processing printer, might take about two minutes to print. With the Starwriter, it might take closer to three. The typical 45 cps printer retails for about $3, 000. But the Starwriter 25 retails for about $1, 895— thus saving you about $1, 000. And therein lies the biggest difference between the Starwriter 25 and the more expensive, daisy wheel printers. The Starwriter 25 comes complete and ready-to-use, requiring no changes in hardware or software. It uses indus- try-standard ribbon cartridges, and it's "plug-in" compatible to interface with a wide variety of systems, to help lower system-integration costs. Using a 96-character wheel, it produces excellent letter-quality print- ing on three sharp copies with up to 163 columns, and offers the most precise character-placement available, for out- standing print performance. Cltoh's warranty; 3 months on parts and labor, sup- ported by one of the best service organi- zations in the industry. 1000 OFF Leading Edge Products, Inc., 225 Turnpike Street, Canton, Massachusetts 02021 Dear Leading Edge: I'd like to know more about the Starwriter, and how spending a minute can save me a grand. Please send me the name of my nearest dealer. Name- Title- Company. Street State Jip_ Phone: Area Code - Number LEADING EDGE. Leading Edge Products, Inc., 225 Turnpike Street, Canton, Massachusetts 02021 Dealers: For immediate delivery from the Leading Edge Inventory Bank™call toll free 1-800-343-6833 In Massachusetts, call collect (617)828-8150. Telex 951-624 Listing 4: EXP2 text-expansion routine. This routine takes the output of COMP2, information expressed in a packed Huffman code, and decodes it using the binary tree of figure 2. The decoded character is displayed via a user-supplied subroutine named DISP. The routine is written in 8080 machine code. 3000 3000 3000 3000 3000 3000 3000 3000 3000 3000 3000 3000 3000 3000 31 00 00 3003 21 02 41 3006 22 CO 30 3009 21 00 41 300C 4E 300D 23 300E 46 300F 3E 01 3011 32 C2 30 3014 C5 3015 21 74 30 3018 E5 3019 2A CO 30 301C 3A C2 30 301F 47 3020 7E 3021 17 3022 05 3023 C2 21 30 3026 3E 00 3028 17 3029 4F 302A 06 00 302C 22 CO 30 302F El 3030 09 3031 7E 3032 17 3033 DA 43 30 3036 IF 3037 5F 3038 16 00 303A 19 303B CI 303C CD 55 30 303F C5 3040 C3 18 30 3043 IF 3044 E6 7F 3046 5F 3047 16 00 3049 19 3 04 A 7E 304B CD 00 C5 304E CI 3 04F CD 55 30 3052 C3 14 30 3055 OB 3056 79 3057 BO 3058 CA oc 00 305B 3A C2 30 305E 3C 305F 32 C2 30 3062 FE 09 0000 0001 0002 On 03 0004 0005 0006 0007 0008 0009 0010 0011 0012 0015 0020 0030 0040 0050 0060 0070 0074 0076 0080 0090 0100 0110 0120 0122 0124 0126 0128 0130 0132 0134 0136 0140 0150 0160 0170 0180 0190 0200 0205 0210 0220 0230 0240 0250 0270 0280 0290 0294 0296 0297 0298 0299 0305 0310 0320 0330 0340 0350 0360 0365 0370 0380 0385 0390 *THIS PROGRAM ACCEPTS DATA PREPARED BY THE DATA COMPRESSION •(HUFFMAN CODE) PROGRAM THE DATA BUFFER HAS THE BIT COUNT *IN THE FIRST TWO BYTES. THE PROGRAM RUNS UNTIL ALL *BITS HAVE BEEN PROCESSED THE PROCESSING CONSISTS OF •ADDING A DATA BIT TO THE TABLE ENTRY POINT, GETTING AN •INCREMENT WHICH POINTS TO THE NEXT 0-1 PAIR AND CONTINUING *UNTIL A TAG IS FOUND IN BIT 7 THIS SIGNIFIES THAT THE *NEXT TABLE ENTRY IS THE DESIRED CHARACTER. *THIS IS THE PACKED VERSION WHICH PROCESSES DATA FROM *8 BIT BYTES, MSB FIRST. DISP: EQU 0C500H MON: ECU OOOCH SP: EQU 6 LXI SP,0 LXI H.DBUF+2 SHLD DADD LXI H.DBUF MOV C,M INX H MOV B,M MVI A, 1 ST A POS EXP: PUSH B LXI H.XTAB NEXT: PUSH H LHLD DADD LDA POS MOV B,A MOV A,M BIT: RAL DCR B JNZ BIT MVI A,0 RAL MOV C,A MVI B,0 SHLD DADD POP H DAD B MOV A,M RAL JC OUTCH RAR E,A D,0 D B CALL DECB PUSH B JMP NEXT RAR 7FH E,A D,0 D A,M CALL DISP POP B CALL DECB JMP EX" DECB: DCX B MOV A,C ORA B JZ MON LDA °OS INR A STA POS CPI 9 ;DISPLAY CHARACTER ; MONITOR RETURN OUTCH: MOV MVI DAD POP AN I MOV MVI DAD MOV FIRST BIT NEXT DATA BIT COUNT ADDRESS {INITIALIZE POSITION ;DECODE TABLE ;GET BIT POSITION ;GET ;GET DATA DESIRED BIT INTO CARRY ; RE STORE SINGLE BIT -.DATA VALUE ; TABLE + DATA BIT ;GET POINTER ;TABLE+DATA BIT + POINTER ; REDUCE BIT COUNT ;REMOVE TAG ;GET DECODED CHARACTER {REDUCE BIT COUNT {UPDATE BIT POSITION ;8 BITS PROCESSED? Listing 4 continued on page 240 238 April 1981 © BYTE Publications Lie DYNACOMP Quality software for^ : ATARI PET APPLE II Plus TRS-80 (Level II)* NORTH STAR CP/M 8" Disk GAMES, SIMULATIONS, EDUCATION and MISCELLANEOUS BRIDGE 2.0 (Available for all computers) Price: $17. 95 Cassette /SI 1.95 Diskelle An all-inclusive version of this mm! popular of card games. This program bolh BIDS and PLAYS either :ontracl or duplicate bridge. Depending on the contract, your computer opponents will either play the offense OR defense. If you bid loo high, the compuler u ill double youi contract! BRIDGE 2.0 provides challengint entertainment for advanced players and is an eicellenl learning tool for the Price: $14.95 Cas.se II* /SIS. 95 Diskette game. Hearts is a trick -oriented game in which the purpose is no! lo :r opponents who are armed with hard-lobeal playing strategies Price: SI 1.95 DuMtle/S 15.95 Diskelle en nip iet( alsll e cards one alalimc and you (and ilie compu cr) bet on what you s c. The if Oil Lis Ho s bluffs Also included is a fivee ird draw poker beltin 6K ATARI Colo . graphics sound. HEARTS 1.5 (Available for all computers) An exciting and entertaining compuler version of this popular c; take any hearts or the queen of spades. Play againsl two comp STUD POKER (ATARI only) computer does not cheat and usually bets lice program. This package will run on a POKER PARTY (Available for all computers) Price: S17.95 CasMfte/S21.95 Diskette POKER PARTY is a draw poker simulation based on the book. POKER, by Oswald Jacoby. This is Ihe mosi comprehensive version available for microcomputers. The party consists of yourself and six olhcr (computer) players Each or these players (you will gel lo know them) has a different personality in ihe form of a varying propensity lo bluff or fold under pressure. Practice with POKER PAR- TY before going lo thai expensive game lonight! Apple Cassette and diskette versions require a 32 K (or larger) Apple II. V AI.DEZ (Available for all computers) Price: S14.95 Cassette /SIB. 95 Diskette A simulation of supertanker navigation in the Prince William Sound and Valdci Narrows. The program uses an extensive 256X256 de- ment radar map and employs physical models of ship response and tidal patterns. Chan youi own course through ship and iceberg traf- fic. Ant standard terminal may be used for display. FLIGHT SIMULATOR (Available for all computers) ion of take-off, flight and landin >fa real airfoil. Yoi d flyer ei o perform loops, half-ri nilar acrobatic Price: 517.95 Cause lie/ $2 1. 95 Diskette The program ulili/cs aerodynamic equations and the galion using radials and compass headings. The more Price: $14.95 Cassetle/SIB.W Diskette ed version of the classic card game, cribbogc. It is an eicellenl program for the crib- is the beginner wishing to learn Ihe game, in particular ihe scoring and jargon. The K ihe top of the display (utilizing the TRS-80's graphics capabilities), with ihe cards loints using the (radilionil phrases. CRIBBAGE 2.0 (TRS-80 only) This is a well-designed and nicely execute bage player in search of a worthy oppont standard cribbage score board is continu; shown underneath. The compuler auton CHESS MASTER (North Star and TRS-80 only I price: $19.95 Cassette/ $23. 95 Diskette This complete and very powerlul program provides five levels of play. It includes castling, en passant captures and the promotion of pawns. Additionally, the board may be preset before ihe start of play, permitting the examination of "book" plays. To maximize execu- lion speed, ihe program is written in assembly language (by SOFTWARE SPECIALISTS of California). Full graphics are employed in Ihe TRS-80 version, and two widths of alphanumeric display are provided lo accommodate North Star users. S I A KTREK 3.2 (Available Tor all computers) This is Ihe classic Startrek simulation, but wiih several new features. For example, il warning while also attacking starbases in olher quadranls. The Klingons also attack v. shot at! The situation is hectic when the Enterprise is besieged by three heavy cruisers a Price: S 9.95 Cass* I le/S 13.95 Diskette Klingons now shooi at the Enterprise without h bolh light and heavy cruisers and move when la starbaseS.O.S. is received! The Klingons gel Price: $10.95 Cass* t le/S 14. 95 Diskelle lie TV screen to "roll" a ball into a hole in the screen. Sound simple? Not when the hole gels smaller and smaller! A built-in timer allows you to measure your skill againsl others in this habit-forming action game. GAMES PACK I (Available for all computers) Price: $9.95 Casaelle/S 13.95 Diskette GAMES PACK I contains the classic computer games or BLACKJACK. LUNAR LANDER. CRAPS. HORSERACE. SWITCH and more. These games have been combined into one large program for ease in loading. They are individually accessed by a convenient GAMES PACK II (Available for all computers) Price: $9.95 Cassette /SI 3. 95 Diskette GAMES PACK II includes Ihe games CRAZY EIGHTS, JOTTO. ACEY-DUCEY, LIFE. WUMPUS and others. As with GAMES PACK I, all the games are loaded as one program and are called from a menu. Why pay 17.95 or more per program when you can buy a DYNACOMP collection for jusl J9.95? NOM1NOES JIGSAW (ATARI and TRS-M oily) NOM INOES JIGSAW is an intriguing and sophisticated graphical puzzle. The jigsaw c( domly chosen shapes (nominees), of which there are 60 types. By knowing thai the shi Ihe shape at each location, all the nominocs may be eventually deduced. Scoring is basei MOVING MAZE (Apple only) MOVING MAZE employs ihe games paddles lo direct a puck from one side of a (and randomly) buill and is continually being modified. The objective is lo crosr Scoring is by an elapsed time indicator, and three levels of ploy are provided. Price: $16.95 Ciuwette/S20.9S Diskette siits of a 9 by 9 board partially filled with ran- is must be legally connected, and by guessing Price: $10.95 Cassette/S 14.95 Diskette o Ihe other. However, Ihe maze is dynamically iaze without touching (or being hit by) a wall. BLACK HOLE (Apple only) This is an exciting graphical simulai that the tidal stress destroys i Price: $14.95 Cassetle/S 18.95 Diskette n of the problems involved in closely observing a black hole with a space probe. The object is lo nc, an orbil close to a small black hole. This is to be achieved without coming so near the anomaly -. Control of the craft is realistically simulated using side jets for rotation and main thrusters for mploys Hi-Rcs graphics TEACHER'S PET I (Available for all computers) Price: $ 9.95 Caiselte/S 13.95 Diskelle This is the first of DYNACOMP's educational packages. Primarily intended for pre-school to grade ), TEACHER'S PET provides ihe young student with counting practice, letter. word recognition and three levels of math skill exercises. Price: S 9.95 Cassette/S 13.95 Diskelle n used in local CRYSTALS (ATARI onlyl A unique algorithm randomly produces fascinatii two patterns are the same, and Ihe combined eff CRANSTON MANOR ADVENTURE (Norlh Star only) At last! A comprehensive Adventure game for the Norlh Star. CRANSTON MANOR ADVENTURE lakes you into myslerious CRANSTON MANOR where you attempt (o gather fabulous treasures. Lurking in the manor arc wild animals and robots who will not give up the treasures without a Tight. The number of rooms is greater and the associated descriptions are much more elaborate than Ihe H popular series of Adventure programs, making ihis game (he lop in its class. Play can be stopped ai any lime and the status Price: $19.95 :. Rcqui: i J2K. NORTH STAR SOFTWARE EXCHANGE (NSSE) LIBRARY DYNACOMP now distributes ihe 20 • solume NSSE library. Mosl of (hese diskel Price $9.95 Diskette Circle 154 on inquiry card. Availability DYNACOMP software is supplied with complcli TRS-HOlLevel III and Apple (Applesoft) cassette alien containing clear explanations and example! :e (ATARI requires 24K). Except where noted, programs d diskette as well as North Star single density {double den rd (IBM format) 8" CP/M floppy disks for systems m Ml Olherwise specified, all vailable on ATARI, PET. impaiiblOdiskette.Addi- under M8ASIC. BUSINESS and UTILITIES MAIL LIST II (Apple and North Star diskettes only) This many-featured program now includes full alphabetic and lip code sorting as well as Til defined code, client name or Zip Code. The printout format allows the use of standard size i thin 1 100 entries (single density Norlh Star or Apple DOS 3.2; over 2200 with double dc: Price: $24.95 meiging. Entries can be retrieved by user- Idress labels. Each diskette can store more ily North Star or Apple DOS 3.3)! EORM LETTER SYSTEM (FLS) (Apple and North Star diskette only) price: $17.95 FLS may be employed to generate individually addressed form letters. The user creates the address Tile and separately composes the let- ter. FLS will ihen print form letters using each address. FLS is completely compatible with MAIL LIST II. which may be used lo manage your address Tiles. FLS and MAIL LIST 11 are available as TEXT EDITOR I (Letter Writer) suited for composing letters and is quile combined package for 137. 9S. Price: $14.95 Cass*lle/SlS.95 Diskette widths and simple paragraph indexing. This text editor is ideally arger jobs. Available for all computers. Price: $34.95 Diskette iplify your personal finances. Features payee; optional priming of Price: $19.95 ; name). Commer- Rcference records PERSOMAL FINANCE SYSTEM (ATARI only) PFS is a single disk menu oriented system composed of 10 programs designed to organize a include a 300 transaction capacity: fas! access; 26 optional user codes; data retrieval by reports: checkbook balancing; bar graph plotting and more. Also provides on the diskelle is ATARI DOS 2. FINDIT (North Star only) This is ■ (hree-in-one program which maintains information accessible by keywords of three types: Personal (eg: la cial (eg: plumbers) and Reference (eg; magazine articles, record albums, elc). In addition to keyword searches, [he niversary and appointment searches for Ihe personal records and appointment searches for the c are accessed by a single keyword or by cross-referencing two or three keywords, DFILE (North Star only) This bandy program allows North Star users to maintain a specialised data base o variably accumulates. DFILE is easy lo set up and use. It will organize your disks gram. COMPARE (North Star only) Price: $12.95 COMPARE is ■ single disk utility software package which compares two BASIC programs and displays Ihe Tile sizes of the programs in byres, the lengths in terms of the number of slalemenl lines, and [he line numbers at which varioui listed differences occur. COMPARE permits the user lo examine versions of his software to verify which are the more current, and lo clearly identify ihe changes made dur- ing develop men l. COMPRESS (North Star only) COMPRESS is a single-disk utility program which re BASIC programs. The source Tile is processed one -. File ci Price: SI 2.95 ves all unnecessary spaces and (optionally) REMark statements from North Star at a time, thus permitting very large programs to be compressed using only a of 20-50* are commonly achieved. GRAFIX (TRS-80 only) Price: $12.95 C*ia«lle/$16.95 Diskette This unique program allows you lo easily create graphics directly from the keyboard. You "draw" your figure using the program's ex- tensive cursor controls. Once the figure is made.it is automatically appended to your BASIC program as a siring variable. Draw a "hap- py face", call il HI and then print il from your program using PRINT HSI This is a very easy way lo creale and save graphics. TIDY (TRS-80 only) Price: $10.95 Cass*lt*/$ 14.95 Diskette TIDY is an assembly language program which allows you to renumber ihe lines in your BASIC programs. TIDY also removes un- necessary spaces and REMark statements. The result is a compacted BASIC program which uses much less memory space and executes significantly faster. Once loaded. TIDY remains in memory; you may load any number of BASIC programs without having to reload TIDYI STATISTICS and ENGINEERING DATA SMOOTHER (Not available for ATARI) Price: $14.95 CasMtte/$18.95 Diskette This special data smoothing program may be used to rapidly derive useful information from noisy business and engineering data which are equnlly spaced. The soflware features choice in degree and range of fit, as well as smoothed first and second derivative calculation. FOURIER ANALYZER (Available for all computers) Price: $14.95 Cassetie/$18.95 Diskette Use this program to examine the frequency speclra of limited duration signals. The program features automalic scaling and plotting of the input data and results. Practical applications include Ihe analysis of complicated patterns in such fields as electronics, communica- TFA (Transfer Function Analyzer) This is a special soflware package which may be used lo evaluate the in examining their response (o pulsed inputs. TEA is a major modifica □rienled decibel versus log-frequency plol as well us data editing featuri miHc u . TFA is n engineering tool. Available for all computers. Price: $19.95 Casselle/S23.95 Diskette sfer functions of systems such as hi-fi amplifiers and Tillers by in of FOURIER ANALYZER and contains an engineering- s FOURIER ANALYZER is designed for educational HARMONIC ANALYZER (Available for all computers) HARMONIC ANALYZER was designed for the spectrum analysis of repetitive editing and storage/ retrieval as well as data and spectrum plotting. One particula equally spaced or in order. The original data is sorted and a cubic spline intcrpolat: algorithm. Price: S24.95 Cass* I le/S 2*. 95 Diskelle waveforms. Features include data file generation, y unique facility is that the input data need not be n is used lo create Ihe data file required by ihe FFT REGRESSION I (Available for all computers) Price: $19.95 Cas*ette/$23.9S Diskelle REGRESSION I is a unique and exceptionally versatile one -dimensional least squares "polynomial" curve fitting program. Features in- clude very high accuracy; an automalic degree delermination option; an extensive inlerno! library of filling functions; data editing; automalic dala and curve plotting; a statistical analysis (eg: standard deviation, correlation coefficient, elc.) and much more. In addi- tion, new Ills may be tried without reentering the dala. REGRESSION I is certainly Ihe cornerstone program in any data analysis sofl- ware library. REGRESSION II (PARAFIT) (Available for all computers) Price: $19.95 Caisel le/S23.95 Diskette PARAFIT is designed to handle those cases in which Ihe parameters are imbedded (possibly nonlinearly) in Ihe filling function. The user simply inserts the functional form, including the parameters (A(l), A(2), elc.) as one or more BASIC statement lines. Data and nipulated and plotted as with REGRESSION I, Use REGRESSION I for polynomial Tilling, and PARAFIT for [hose ariablcs. Besides perfor MULTILINEAR REGRESSION (MLR) (Available Tor all computers) MLR is a professional soflware package Tor analyzing dala sets containing two or more linearly indc; ing the basic regression calculation, (his program olio provides easy to use data entry, storage, relri [ion, [he user may interrogate ihe solution by supplying values for the independent variables. The r limited only by the available memory, REGRESSION 1, II and MULTILINEAR REGRESSION may be purchased together for 149.95 (three cassellcs) or 161.95 [three diskette*). BASIC SCIENTIFIC SUBROUTINES, Volume I (Not available for ATARI) DYNACOMP is ihe exclusive distributor for Ihe software keyed lo the text BASIC Scientific Subroutines. Volume I by F. Ruckdeschel (see ihe BYTE/McGraw-Hill advertisement in BYTE magazine. January 1981). These subroutines have been assembled according to cclion II: Chapter cction Hi Chapter cclion «: Chapter 2 and 3: Dala and function plotting, complex variables I: Matrix operal: Random number generaiors, series approximations : $14.95 Cajselte/JI8.9J Diskelle All three collections arc available (or S39.95 (three cassettes) and 149.9! (three diskettes). Because the text is a vital pari of the documentation, BASIC Scientific Subroutines, Volume I is SI9.95 plus 75* postage and handling. a DYNACOMP for ROOTS (Available for all computers) In a nutshell, ROOTS simultaneously of the polynomial, and because Ihe proccdi and the calculated roots are substituted bu Price $9.95 Cus«tte/$13.95 Diskette ill the zeroes of a polynomial having real coefficients. There is no limit on the degree eralive, [he accuracy is generally very good. No initial guesses are required as input, the polynomial and ihe residuals displayed. ATARI. PET. APPLE II. TRS-ftO. NORTH STAR. CP/M and II ! registered trade n Ordering Information 1 orders are processed and shipped postpaid within 48 hours. Please enclose payment with o . by VISA or Master Card, include all numbers on card. For orders ouiside North Ameri Add 12.50 to diskelle price for 8" floppy disk (IBM format sofi sectored, CP/M. Mict •TRS-80 diskettes are nol supplied with DOS or BASIC. Deduct 10% when ordering 3 or more programs. a add 10% for shipping and handling. e for detailed descriptions of these and other programs from DYNACOMP, Inc. 1427 Monroe Avenue Rochester, New York 14618 24 hour mail order phone: (716)586-7579 Office phone (9AM-5PM EST): (716)442-8960 Nct, York Stal* roMrati pkuc *rfd 7* NYS ufe. in. Listing i continued: 3064 CO 3065 3E 01 3067 32 C2 30 306A E5 306B 2A CO 30 306E 23 306F 22 CO 30 3072 El 3073 C9 3074 3 074 3074 3074 3074 3074 3074 2A 3075 01 3076 02 3077 08 3078 82 3079 02 307A 45 307B 82 307C 82 307D 49 307E 52 3 07F 06 3080 01 3081 82 3082 82 3083 4F 3084 41 3085 82 3086 02 3087 4E 3088 03 3089 81 308A 44 308B 03 308C 81 308D 50 308E 03 308F 81 3090 56 3091 02 3092 05 3093 82 3094 82 3095 4 A 3096 58 3097 03 3098 81 3099 4B 309A 82 309B 82 309C 5A 309D 51 309E 02 309F OE 30A0 03 30A1 81 30A2 54 30A3 02 3 0A4 05 30A5 82 30A6 82 30A7 59 3 OAR 47 30A9 82 30AA 82 30AB 55 30AC 4D 0400 0410 0420 0430 0440 0442 0444 0450 0460 4000 4010 4020 4030 4040 4050 5000 5010 5020 5030 5040 5050 5060 5070 5080 5090 5100 5102 5104 5106 5108 5110 5120 5130 5140 5150 5160 5170 5180 5190 5200 5210 5220 5230 5240 5250 5260 5270 5280 5290 5300 5310 5320 5330 5340 5350 5360 5370 5380 5390 5400 5410 5420 5430 5440 5450 5460 5470 5480 5490 5500 5510 5520 ; RESET POSITION ; UPDATE BYTE ADDRESS RNZ MVI A,l ST A POS PUSH H LHLD DADD INX H SHID DADD POP H RET *THE DECODE TABLE HAS THE FOLLOWING FORMAT: *THE TABLE VALUE IS THE INCREMENT NECESSARY TO GET THE *NEXT 0-1 PAIR AS THE PROGRAM STEPS THROUGH THE DATA *THE TABLE VALU JUST PRECEEDING A CHARACTER HAS A TAG *SET IN BIT 7, IN ADDITION TO THE INCREMENT, TO INDICATE *THAT THE NEXT VALUE IS A CHARACTER. XTAB: DB 42 DB 1 DB 2 DB 8 DB 130 DB 2 DB •E' DB 130 DB 130 DB •I' DB •R' DB 6 DB 1 DB 130 DB 130 DB •0' DB •A' DB 130 DB 2 DB • N i DB 3 DB 129 DB 'D' DB 3 DB 129 DB i P i DB 3 DB 129 DB lyi DB 2 DB 5 DB 130 DB 130 DB 'J' DB •X' DB 3 DB 129 DB •K' DB 130 DB 130 DB CHOOSE FIRST BIT U-> J ♦ ,J ADD 2 r^i OFF a ^ & ) CHOOSE SECOND BIT + 3 1 8 OFF i J ♦4 130 ON 1 * 5 ADD 2 r"?l OFF B ) CHOOSE THIRD BIT \£) J + 6 E OFF 130 ■ I2B + 2 ON a 1 ■ 130 ) CHOOSE FOURTH BIT ♦ 8 130 ON i / + 9 ADD 2 ■ 1010 1 DECODED + 10 R + 11 6 + 12 1 1 Figure 3: Use of the binary tree tables in programs EXPl and EXP2. This annotated table interprets the first 13 bytes of the lookup table in both the code-expansion routines. It cor- responds to the part of the binary tree in figure 2 that leads to the letters E, I, and R. This figure shows the process by which 1010 is decoded as the letter I. 246 April 1981 © BYTE Publications Inc The I SUPRBPAIN" INTE3TEC DATA SYSTEMS 64K ONLY $3395 32K $2795 More than an intelligent terminal, the SuperBrain outperforms many other systems costing three to tive times as much. Endowed with a hefty amount o) available software (BASIC, FORTRAN. COBOL), the SuperBrain is ready to take on your toughest assignment. You name it! General Ledger. Accounts Receivable, Payroll, Inventory or Word Processing. . .the SuperBrain handles all of them with ease. FEATURES INCLUDE: • 2 dual-density minifloppies with 360K bytes of disk storage • A CP/M Disk Operating System with a high-powered text editor, assembler and debugger SUPER BRAIN HARD DISKS TO ORDER CALL (212) 687-5000 H i*] :*'« 10 megabyte disk and mirror available 5 »— , t, . a " APPLE 1 1 PLUS for P" ce A complete self-contained computer syslem with APPLESOFT floating point BASIC in ROM. full ASC 1 1 keyboard in a light weight molded carrying case. Features Include: • auto-start ROM • Hi-Res graphics and 15 color video output. • Expandable to 48K. Supertalker $279 Micromodem $379 Disk 645 Superterm (24 x 80) 395 Add-on Disk 525 Speechlab 229 Pascal Card 495 Communication Card. .. . 225 Business Software 625 Modem 200 Monitor 159 Graphics Printer 595 Printer Card 180 Graphics Tablet 795 ^IS FINALLY HERE 128KRAM!! CLOSE OUT SPECIALS! Llit Special Chatsworth Card Reader lor TRS-80 750 450 Axiom 801 495 195 Protoline PET to Centronics Interlace. .. . 199 49 Microtronics PET/Ham Interface 125 49 TEXAS Instruments 99/4 S695 Over 1000 Software (with 13" color Monitor) , . «... tapes, books, disks, ieedex-80 12 "$89 on display. Come in and browse. NEW96K \ 80 Column m. Commodore CBM Basic 4.0 Operating System • 80 column by 25 line display • 12" CRT • New screen editor • Split screen processing • Super fast string handling • 15 additional basic commands • Supports relative record processing MUSS MpW 8096 rl _ n _ 96K memory $1795 Call for price \ NEW 8050 DUAL DISK $1795 1 million bytes on-line storage and DOS 2.fJioperating system NEW 2031 SINGLE DISK $595 Commodore Computer These low cost Commodore PET Business Computers have virtually unlimited business capabilities. Accounts Receivable. Inventory Records, Payroll, and §~ other accounting / functions. / § PET 16N & 32N / I COMPUTERS ' • Full size keyboard • 16 or 32.000 Bytes Memory • Level III Operating System , • Full Screen \ Editor " 1 — —__ ______^ - j • Upper lovv eTC|£|& 64 graphic characters PET DUAL FLOPPY DISK 1 • Stores 360.000 Bytes on-line • Microprocessor controlled • Uses single or dual sided floppies HI-SPEED PRINTER second • Up to 4 copies 8" wide • Microprocessor Controlled • Prints All Graphics • Full Formatting Capability PRINTERS, CENTRONICS SALE 737-3 ONLY $888 CENTRONICS 704 80 cps Bi-Directional • Up tol5' °aper Width . 9x g Matrix Upper/Lower Case • Trantor Feed • HS-232 Serial Interface $1795 CENTRONICS 700-9 $1 295 List $1895 • 60 cps • Up to 15" paper width • Tractor Feed • Parallel Interface for Apple & TRS-80 • 2 channel vertical forms! • Top of Form! CENTRONICS 737 Parallel $895 1 VFt-300 $1795 (25cps Letter Quality) EPSON MX-80 $ 645 Paper Tiger 445 795 Paper Tiger 460 1295 MONITORS SANYO 12" GREEN $355 BMC 12" GREEN 295 LEEDEX 13" COLOR 449 ZENITH 13" COLOR 395 LEEDEX 12" B&W 159 ANDERSON JAC0BS0N 841 I/O Terminal Ideal for word processing and small businesses. ASCII Code 15 CPS Printout High Quality Selectric Printing • Reliable heavy duty mechanism Completely Refurbished by A.J. * Delivered FREE to nearest service center Serial s 995 DIABLO 630 Letter Quality Special $2495 List $2755 • 40 Cps • Uses all 100 metal & plastic daisy wheels • Automatic bidirectional printing Fewer moving parts On Site Warranty DEALER INQUIRIES INVITED ON DIABLO, CENTRONICS, SUPERBRAIN, DYNABYTE MBtJ XYMEC HQ 1000 with 10, 12, 15 Pitch & Proportional Spacing $2495 Z-80 controlled Up to 198 columns VISA Min. Credit Card Order $75 N Y residents add 8% sales tax * Same day shipment on prepaid and credit card orders TO ORDER CALL (212) 687-5000 Mo 3S 1MSitlM yU , C*f\tl Dl I I L P EAtf^TODV 485 Lexin 3 ton Ave - New York - NY 10017 (46th St. Lobby) lie IsUIYIfU I Cn \~H\s I \Jr\ I® Foreian order desk - Telex 640055 The single board microcomputer that's perfect for CP/ Net™ Everything you need for a network slave is built in: Z-80 processor, 64K dynamic RAM, even the console serial port. The forthcoming expansion board will add additional ports, priority interrupt control, and IEEE S-100 bus master capability for the network master processor. And MuSYS delivers all the software sup- port you need to take advantage of CP/NET™ and the advanced MP/M™ operating system. For your multi- user system, it's the ideal way to add stations, share common resources (peripherals, programs, data bas- es), and increase total throughput, while maintain- ing hardware isolation for each user. Just $1,395 ea. Generous dealer and quantity dis- counts available. Call or write today for more details. CP/Not and MP/M are trademarks of Digital Research. Multi-user Microsystems 1451 Irvine Blvd., Suite 11, Tustin, CA 92680 (714) 730-5692. TWX: 910-595-1967 CABLE: MUSYSTSTN The index value here, a 1, is added to the previous result, giving TAB + 2. The first bit has now been processed. Beginning on the second bit, is added to the previous result and the new index value pointed to is 2. This is added to the previous result, giving a new address of TAB + 4. The second bit has now been processed. The next data bit, a 1, is added to the previous result, giving the address TAB + 5. Adding the index value at this location, a 2, gives the new address, TAB + 7. The third bit has now been processed. Adding the last data bit, a 0, gives the entry 130. The fact that this value is greater than 128 proves that it is really an index value of 2 with the flag bit set; 130 = 128 +2. This tells the user that the next entry, two locations further, is the desired character. Adding the index value of 2 points you to the letter "I". Since a letter was found, the process is repeated from the beginning, continuing with the next bit in the data stream (providing that the supply of data has not been exhausted). Shorter codes are used for the more frequently occurring data elements, and longer codes are used for less frequently occurring data elements. COMP2 Description The COMP2 program, given in listing 3, is similar to COMPl except for one significant difference — the serial bit stream that results from the encoding process is packed and stored 8 bits to the byte. This provides true compression and is useful when the compressed file is stored in main memory or when the mass-storage device requires an 8-bit word. An interesting occurrence in using a compression scheme like this is that a low degree of data encryption occurs automatically when the bit stream is broken into 8-bit bytes. Referring back to the example where the word "compression" was represented by 47 bits, you can see that the 8-bit bytes look like the follow- ing: (Binary) (Hexadecimal) (ASCII Meaning) 01000111 47 G 00001111 OF SI (Control character) 01011011 5B Left bracket 10001100 8C Not defined in 7-bit ASCII 11010101 D5 Not defined in 7-bit ASCII 1101100 D(?) Insufficient data If someone looked at this data, it would not be im- mediately obvious that this is the word "compression". Some knowledge about the processing method or some effort in decoding it would be necessary to retrieve the original word. EXP2 Description The EXP2 program, given in listing 4, is similar to EXP1 except that it expects to find the data to be decoded in a packed form of 8-bit bytes. It works in conjunction with COMP2. As in EXPl, the decoded data is sent to some sort of terminal device. Any other destination could be used with a slight code change. 248 April 1981 © BYTE Publications Inc Circle 158 on inquiry card. BASF presents a strong case for floppy disks. Tough Tyvek sleeve no paper dust, no static electricity. 100% certification - every single disk tested at thresholds 2-3 times higher than system requirements, \ to be 100% error-free ^ Cross-linked oxide \ \(v'* coating -for low head wear and long, trouble-free media life, v Double lubrication- N. T £tr *»"«*{" ^k lubricants both in the V #*••» "* jfl formula and on the 'hm fm disk surface, to mini- mize media wear due . Jm to head friction . ""-^^^ J ■ Bi-axially oriented ^M Kk^'^' ,V ^&\>- 1 B 1 1 polyester substrate- j^k\ for uniform and reli-- — ——-j^k\ able performance j/^. year after year. SyA j^PP • K»M 'rj>> lexyDisk Not just a strong case . . .but an attractive, dust- proof, easy-to-carry case, with 40 BASF FlexyDisks® included. Best of all, our new case is available in both 5.25" and 8" configurations. Our strongest case is inside -BASF FlexyDisks? the product of more than four decades of experience in magnetic media . . .the best value available in premium-grade floppy disks. For the name of your nearest supplier, write BASF Systems, Crosby Drive, Bedford, MA 01730, or call 617-271-4030. Circle 159 on inquiry card. BASF Systems Corp. Computer Mktg. Svcs. Crosby Drive Bedford, MA 01730 Please send me more information and prices on the new BASF 40-pack in □ 5.25" □ 8" configuration. BASF 1 Name Title 1 Company ■ Address City State Zip 1 Telephone L BYTL^ Listing 6: Listing of the execution of program FREQ (listing 5). This listing is the result of running the FREQ program, using eight lines of BASIC code as the text to be analyzed. OK RUN OF FREQUENCY ANALYSIS PROGRAM ENTER ANALYSIS TEXT, TERMINATE WITH % ? "120 f=n-l" ? "125 forn=0 to f" ? "130 l=len(b$(n))" ? "140 for k= 1 to 1" ? "150 a$=mid$(b$(n),k,l)" ? "160 for 5=0 to d" ? "170 if l$(j)=a$ s°to 220" ? "ISO next j" ? % LETTER FREOJENCY ANALYSIS LETTER COUNT PROBABILITY 3 A M 6 7 G 8 X 5 E B K A I D » R J 2 L T ( ) F N $ O 1 7.75194E-03 7.75194E-03 7.75194E-03 7.75194E-03 7.75194E-0? 7.75194E-0'' 7.75194E-0'' 7.75194E-03 7.75194E-0- 5 2 1.55039E-02 2 1.55039E-02 2 1.55039E-02 2 1.5 c; 039E.02 2 1.55039E-02 2 1.550" 5 9E-02 2 1.55039E-02 2 1.5 I >039E-02 •? 2. o 2558E-02 3 2.32558E-02 4 3.10078E-02 4 3.10078E-02 5 , .87597E-02 5 3.87597E-02 5 3.87597E-02 6 4.65116E-02 6 4.65116E-02 6 4.65116E-02 7 5. 42 63 6E- 02 8 6.20155E-02 10 7.75194E-02 11 8.52713E-02 21 .162791 Line Operation Performed 10 Assign string space. 12 Maximum number of unique sym- bols expected. 15 Number of unique symbols entered. 20 Text working buffer. 30 Symbol count array. 40 Symbol array. 50 thru 110 Entry of text to be analyzed. 80 Loop control for number of lines (may be increased). 120 F is number of text lines entered. 125 thru 180 Input line is transferred to text buffer. 190 thru 240 Count number of each type of symbol; T is total count; C is count of corresponding symbol in symbol array. 245 thru 278 Sort symbols by count in ascend- ing order. 291 thru 320 Computer probability and output results. Table 3: Operations performed by lines of code in the BASIC program FREQ of listing 5. FREQ Description To aid in doing frequency analysis, a small program, FREQ, was written in Microsoft BASIC. (See listing 5.) This program counts the occurrence of symbols (letters, spaces, punctuation marks, etc) that have been entered and prints the frequency analysis. In order to include spaces in the count, the input array should be initialized to be filled with a symbol not occurring by itself in the text stream. The same symbol can be used to terminate the text-entry operation: I used a percent sign (%). The size of the text block to be analyzed is limited only by available memory. To get a reasonably accurate analysis, the text block should be more than several hun- dred characters and be representative of the entire text. It is not necessary to do a frequency analysis every time a code is constructed. However, the closer the code lengths correspond to the frequency of occurrence, the more effi- cient the resulting compression will be. A sample run of FREQ is shown in listing 6 with the text input being part of the program itself. By comparing this output with the figures of table 1, you can see how the letter frequency for a BASIC source program com- pares to that of plain English text. Finally, since there are no remarks in the FREQ pro- gram, the information in table 3 will help you understand the program. ■ References 1. Hoffman, L J, Modern Methods for Computer Security and Privacy, Prentice-Hall, 1977. 2. Huffman, D A, A Method for Construction of Minimum- Redundancy Codes, Proceedings of the Institute of Radio Engineers, September 1952. 3. Tao, W Y, A Firmware Data Compression Unit, University of Il- linois, January 1974. 4. Williams, Gregg and Rick Meyer, "The Panasonic and Quasar Hand-Held Computers: Beginning a New Generation of Consumer Computers," BYTE, January 1981, pages 34 thru 45. 250 April 1981 © BYTE Publications Inc Can your word processor pass this screen test? WordStar™ software does* ! And does it better than any other word processing system. Not only do you get all the sophisticated features youd expect from the high-priced WP system, with WordStar you have a true screen image of what your printout will look like before you print it! With WordStar, you'll erase, insert, delete and move entire blocks of copy. Page breaks are displayed and automatically revised on the screen. You can specify enhancements like underlining and boldfacing, and much more. And WordStars so much easier to learn because of its unique and extensive self-help menus. Every typist in your office can be an instant screen star. Call (415) 457-8990 and ask for a copy of our WordStar demon- stration booklet. Remember, when you're the star, we're the star. icwPfO, INTERNATIONAL CORPORATION The Star Maker MicroPro International Corporation 1299 4th Street, San Rafael, CA 94901 (415) 457-8990 TELEX 340388 Sold through authorized dealers and distributors only. OEM inquiries invited. 'Runs on most Z80/8080/8085 microcomputers with CP/M (TM of Digital Research); 48K; and terminal with addressable cursor. Circle 160 on inquiry card. BYTE April 1981 251 Build an Intercomputer Data Link Mike Wingfield 93 Pine Hill Rd Bedford MA 01730 Have you ever wanted to share a program or data with someone, but had no way to get it from your machine to his without typing it by hand? While this facility is lacking on most microcomputers, it is so necessary to scientific and business computers that it has long been taken for granted. The power of a computer is greatly enchanced when it can com- municate with geographically distant computers. Computers can attain in- creased efficiency by sharing both resources and data, or by distributing the work load among connected com- puters. These capabilities also in- crease the versatility of the computer as a tool, and make possible such ser- vices as electronic mail and quick ac- cess to data. These and similar advan- tages will become available to the hobbyist and the small businessman through the use of intercomputer data links. This article describes a specific im- plementation of a connection be- About the Author Mike Wingfield graduated from the Univer- sity of California at Los Angeles in 1972 with a PhD in computer science. Presently, he is working for the computer consulting firm of Bolt, Beranek, and Newman in Cambridge, Massachusetts, where his specialty is the design and implementation of intercomputer com- munication software. His hobbies include gardening and experimentation with 6800- and 6809-based microcomputers. The power of a com- puter is greatly en- hanced when it can communicate with geographically distant computers tween two computers that provides a symmetrical facility for terminal link- ing and memory-to-memory file USER A 1 TERMINAL COMPUTER transfers. Terminal linking implies that the output from each terminal is echoed on the remote terminal. File transfer implies the error-free transmission of a block of data from one computer to the other. The pur- pose of this article is to provide in- sight into the requirements of large- scale network design through an ex- amination of one specific implemen- tation. System Overview As presented in figure 1, each end USER B COMPUTER TERMINAL DATA LINK Figure 1: Typical data-link system configuration. Although the connection between the terminal and the computer is hardwired (ie: a direct electrical connection), the data link between computers (bridging a large distance) is usually accomplished via radio or telephone link. 252 April 1981 © BYTE Publications Inc Why is the 88G Printer the new industry leader? QUALITY The attractive, durable 88G casework is formed from impact-resistant, flame- retardant Styron. Microprocessor con- trolled stepper motors provide precision control over print head and paper positioning. Computer quality tractors position paper for readability and are fully adjustable to accommodate varying paper widths. MICROPROCESSOR CONTROLLED INTERFACE The microprocessor array provides the intelligence for a dual RS232 serial and a Centronics® type parallel interface. Both inputs are fully buffered to allow the 88G to receive data and print simultaneously. A IK character buffer is standard with a 2K buffer available as an option. The short line thruput of the 88G has been increased by incorporation of a Quick Cancel feature that fully utilizes the bidirectional/unidirectional printing capabilities. Built-in diagnostic and self-test capabilities allow the user to easily pinpoint system problems and a Power On confidence test verifies operational status of the printer each time power is applied VERSATILITY The 88G prints a full upper and lower case 96 character ASCII set with a crisp, clear 7x7 matrix in 80, 96, or 132 column formats. For text processing and correspondence applications, an 11x7, 80 column serif style matrix can be selected by switch or software command. The dual tractor/pressure-feed paper drive system allows the user to choose either pin-feed, roll, or single sheet papers up to 9.5 inches wide. Complete forms control allows the 88G to be quickly configured for printing single or multiple-ply invoices, purchase orders, checks, or any type of preprinted form. Optional paper roll holders and single sheet feeders can be quickly attached. The wide use range of the 88G makes it the perfect companion for business systems, data processing, RO teleprinter and terminal printer applications. GRAPHICS A high-resolution, dot-addressable graphics option can be added for appli- cations requiring plotting, printing of screen graphics, drawings, illustrations, etc. Single dot print resolution greatly extends the usefulness of the graphics capability. Selection of one of the four horizontal dot densities available customizes the graphic printout, and alphanumerics can easily be included for titling of graphs and illustrations. LONG LIFE RIBBON CARTRIDGE Ribbon difficulties are minimized through use of a continuous loop cart- ridge with a five million character life. It is easily changed without opening the case, and without any complicated or messy threading operations. PRICE Every detail is directed toward providing a heavy-duty, commercial quality printer for only $749.00. No other printer on the market today can provide its quality, features and performance at a comparable price. The 88G is an obvious industry leader. ^Centronics is a registered trademark of the Centronics Data Computer Corp. Micro Peripherals, Inc. 4426 South Century Drive Salt Lake City, Utah 84107 Phone (801) 263-3081 Circle 161 on Inquiry card. Now-Break Through The 64K Micro-Memory Limit! SIXTEEN Bank Selectable 16K Static RAM SAVE $50.QO LIMITED TIME OFFER Don't buy any more antique RAMs (RAM without bank select) — now there's Netronic's new SWEET SIXTEEN board featuring a universal soft- ware bank select system. SWEET SIXTEEN is capable of addressing 2,048 different banks. With SWEET SIXTEEN boards you can add mem- ory beyond the 64K limit, or expand to a multi- terminal system. LOOK AT THESE FEATURES: • 300 NS, low power 2114s. • Software Bank Selector — Universal decoder works with Cromenco. Alpha Micro, Netronics, most other systems, or your design. Onboard dip switches: Bank Select Enable,- Reset Enable,- Reset Disable,- Port Address,- Port Data. • All Inputs And Outputs meet the proposed IEEE standards for the S-100 bus. • 4.0 MHz Operation. • Schmitt Trigger Buffer on all signals for maximum noise immunity. • Addressable On 16k Boundaries, 0-64k, dip switch selectable. • Phantom Option, dip switch selectable. • PWR/MWRITE Option, dip switch selectable. • LED Indicator to display status, • Glass Epoxy PC Board with gold-plated contacts and double-sided solder mask. • Fully Socketed. • Four Separate Regulators for maximum stability. 10-Day Money-Back Policy For Wired & Tested Unit: Try a fully wired board — then either keep it, return it for kit, or simply return il in working condi- tion. Continental U.S.A. Credit Card Buyers ■ ■ ■ ■ Outside Connecticut: ■■■■■ CALL TOLL FREE: 800-243-7428 From Cnnnecticiil Or For Assistance: (203| 354-9375 Please send the items checked below: Q SWEET SIXTEEN kit; No. S-16 . (reg. price S249.95) now $199.95* a SWEET SIXTEEN, fully assembled, tested, burned in,- No. S-16W . . . (reg. price S289.95) now S239.95* *Plus S2 postage 8 insurance. Connecticut residents add sales tax. Total Enclosed: $ □ Personal Check □ Money Order/Cashier's Check D VISA □ Master Charge (Bank No. ) Acct. No. Exp. Date Signature Print Name Address City State Zip ISMVETRONICS RESEARCH & DEVELOPMENT, LTD, 333 Litchfield Rd„ New Milford. CT 06776 v.... Computers can attain increased efficiency by sharing both resources and data. of the connection consists of a com- puter and a terminal (such as a teletype or a video display terminal). The local computer is connected to the remote computer via a data link that is implemented by an asyn- chronous serial hardware interface and the software necessary to support data transfer. The data link may be hardwired if the distance between computers is short; or, it may consist of a pair of modems connected by a telephone line if a hardwired line is inconvenient. Figure 2 illustrates the hardware configuration of each com- puter — in this case, a 6800-based system. Two ACIAs (asynchronous communications interface adapters) provide the necessary interfaces to the terminal and to the line. The soft- ware involved occupies approximate- ly 700 bytes of memory. The user interface can be defined as the view the user has of his computer. The interface to the data-link soft- ware was designed to be as simple as possible (to reduce the amount of software), and yet provide the user with two capabilities: • Echoing of characters typed by one terminal on the other terminal. This feature enables two persons to com- municate with each other. This is the transparent or linking mode, which is the default state of the software. • Initiation of a file transfer from one 6800 MICROPROCESSOR t c c c Ul READ-ONLY MEMORY u. PROGRAMMABLE MEMORY 3Jl ASYNCHRONOUS COMMUNICATIONS INTERFACE ADAPTER (ACIA) .TO OTHER /\/ COMPUTER Ul ASYNCHRONOUS COMMUNICATIONS INTERFACE ADAPTER (ACIA) TERMINAL DATA BUS ADDRESS BUS Figure 2: Hardware configuration of a 6800-based computer. The computer com- municates across the data link by means of the ACIA, which converts the 8-bit bytes of information to a continuous (serial) stream of bits. This serial bit stream is transmitted by use of the modem, which translates between the binary signal and a signal that can be carried across telephone lines. 254 April 1981 © BYTE Publications Inc FOR OVERWORKED COMPUTER OPERATORS, OUR SLC-1 MAKES THE PERFECT ASSISTANT. Your computer may lose track of things once in a while. The time, for example. When it does, your operator has to make sure it gets things right again - which costs you time and money. If they make a keying error, these costs go up. That's one good reason to get your computer a smart new assistant like the SLC-1. It listens to everything your computer says. When it recognizes a key phrase, it flashes back the answer instantly. A battery backup system keeps the SLC-1 running, come power failure or system crash. And unlike your regular operator, the SLC-1 doesn't make mistakes. Plus the SLC-1 does a lot more than timekeeping. It also provides instant answers to a variety of mainframe questions. You pick the key phrase it looks for, and type in the responses. Then -for example -if your computer goes down, it can be automatically re-booted back into action under the SLC-1 's supervision. The SLC-1 does all this because it's driven by its own computer, a 6502 microprocessor. So when you want to use your main computer for something else, you still have - for backup - the SLC-1 , with its own 1 K bytes of RAM (expandable to 12K). But even with its optional 10-digit display, the SLC-1 is inexpensive to hire. And it's simple to train. Just plug it into the RS-232 or 20-mA current loop serial link between your computer and terminal, enter your message responses, and you're all set. So give yourself a break: talk to our personnel counselor today at Digital Pathways, 1260 L'Avenida, Mountain View, CA 94043. Or contact us at (415) 969-7600. TWX 910- 379-5034. We'll introduce you to a new assistant that doesn't talk back. Except to your computer. 7T MEET THE ASSISTANT COMPUTER OPERATOR THAT NEVER TAKES A COFFEE BREAK. Ciicio ii-iti on inquiry card. GENERAL FRAME FORMAT DLE STX (OPC) ETX (CHECKSUM- HIGH) (CHECKSUM- LOW) DATA BYTES Figure 3: Frame format for data transmission. A frame is information that will be transmitted across the data link as a unit and checked for accuracy upon receipt. For the purposes of transmission accuracy, the data is preceded by a header and followed by a trailer. DLE and STX are both 1-byte ASCII characters. (OPC) stands for opcode, which is a 1-byte quantity that tells the receiver what kind of data follows. A running 2-byte total of the data bytes is kept. This is deposited as a checksum, high byte first, and is used by the receiving computer as a check against transmission errors. (o) ADDRESS FRAME: DLE STX 30 (ADDR- LOW) (ADDR- HIGH) DLE ETX (CHECKSUM- HIGH) (CHECKSUM- LOW) (b) DATA FRAME: DLE STX 31 DLE ETX (CHECKSUM- HIGH) (CHECKSUM- LOW) DATA BYTES (c) ACKNOWLEDGE FRAME: DLE STX 32 DLE ETX (CHECKSUM- HIGH ) (CHECKSUM- LOW) DLE STX 33 DLE ETX (CHECKSUM- HIGH) (CHECKSUM- LOW) (d) NEGATIVE ACKNOWLEDGE FRAME: Figure 4: Frame formats for different types of data. The third byte in each frame dictates the type of data sent in that frame. A hexa- decimal 30 means that the current frame contains a 2-byte hexadecimal address, sent high byte first: this is an address frame, with for- mat as illustrated in figure 4a. A hexadecimal 31 denotes a data frame, which is the only frame that has a variable length. (See figure 4b.) Because the end of the data is marked by a DLE ETX sequence, a DLE within the data byte area is transmitted twice to indicate that it is data, rather than the end of valid data. A hexadecimal 32 denotes an acknowledge or A CK frame (figure 4c), while a hexa- decimal 33 denotes a negative acknowledge or NAK frame (figure 4d). The address and data frames are sent to the computer that is receiving data. The ACK and NAK frames are sent from the receiving computer to acknowledge error-free or faulty transmission of the previous frame, respectively. computer to the other. This is done by specifying a local starting address of the file, the remote loading-start address, and the byte count of the file. This is accomplished by a simple command interpreter that asks for these three parameters and initiates the transfer. Data blocks are transmitted by one computer, and their reception acknowledged by the other. This is the file-transfer mode of the software. The following information outlines the sequence of events leading to the transfer of a file between computers. User A dials up user B over the telephone and both computers are connected via modems. (See figure 1.) User B tells user A, via the link, the name and loading location of the desired file. The file can be a BASIC program, an assembly program, a let- ter, or any other kind of file. User A types a control-F that in- itiates the local command interpreter, resulting in "S:" being displayed. User A keys in four hexadecimal digits (representing the source address) and a carriage return. The command in- terpreter types "D:" and waits for four more hexadecimal characters and a carriage return (representing the destination address). Finally, a "#:" directs user A to type in the byte count and a carriage return; this begins the file transfer. When the transfer is complete, user A's computer returns to the linking mode. Further file transfers can then be negotiated before the telephone connection is manually broken. During specification of the ad- dresses and byte count, a backspace erases the previously typed character and a control-X aborts the command interpretation and returns the com- puter to the linking mode. Any illegal hexadecimal characters typed are ig- nored and the terminal bell is sound- ed for each occurrence. Communication Protocol To insure correct interpretation of a sequential stream of bytes, a com- munication protocol that imposes meaning on the data stream must be specified. Computer protocols, like human protocols, are those modes of behavior agreed upon between 256 April 1981 © BYTE Publications Inc JfXfivfccf tie KXyicocy 'r Ss •^* / s gmmavd r GUK ft 9 dliwfflJ^jnetfiyi . J)R more- display several documents aqA J)Vo$ rams at (mee- ts absolutely unecfualed by sty aujev system. j£?ndfiyst car) be modified to suit your needs because we sufefify the source Joe the commar)us.kou can arbWcaxi ly alter the befiavior jf wy commdydf One year's suffiort is included —we (\orft imveyou tojeydfovjowesejfi^fyft our tfjorougf), readable documentation fjas received high aedaimjeom our usecs. r JAmettjyst comes wily Tye,3}>D& C compiler systems Amethyst $350 (less C compiler $250) manual $35 Mince (Amethyst text editor) $125 manual $15 demo disk $10 Scribble (Amethyst text formatter) $125 manual $15 Mince and Scribble ordered together $175 D 48K CP/M required. Available on 8" soft sector diskettes. Mince and Amethyst require a cursor-addressable terminal. Dealer, site, OEM, and **NIX versions and licenses available. Mark of the Unicorn, P.O. Box 423, Arlington, MA. 02174 (617)489-1387 Circle 164 on Inquiry card. BYTE April 1981 257 The days of complicated, unreliable, dynamic RAM are gone: the ultrabyte memory board 6lfln QK I complete kil \ O ■ *m *• %M%t \with1SK memory J Netronics consistently offers innovative products at un- beatable prices. And here we go again — with JAWS, the ultrabyte 64K S100 memory board. ONE CHIP DOES IT ALL JAWS solves the problems of dynamic RAM with a state-of-the-art chip from Intel that does it all. Intel's single chip 64K dynamic RAM controller eliminates high-current logic parts . . . delay lines . . . massive heat sinks . . . unreliable trick circuits. REMARKABLE FEATURES OF JAWS Look what JAWS offers you: Hidden refresh . . . fast performance . . . low power consumption . . . latched data outputs ... 200 NS 4116 RAMs . . . on-board crystal . . . 8K bank selectable . . . fully socketed . . . solder mask on both sides of board . . designed for 8080, 8085, and Z80 bus signals . . . works in Explorer, Sol, Horizon, as well as all other well-designed S100 computers. I GIVE YOUR COMPUTER A BIG BYTE Of MEMORY *1 POWERWITHJAWSSAVEUPTOS900N INTRODUCTORY LIMITED-OFFER SPECIAL PRICES/ | UNDECIDED? TRY A WIRED 1SK JAWS IN YOUR COMPUTER ON OUR IO-DAY MONEY- BACK OFFER /SPECIFY YOUR COMPUTER). CONTINENTAL USA CREDIT CARD BUYERS Otn SIDE CONNECTICUT CALL From Connocliciit Or For AflitUnc l&NETRONICSc CALL TOLL FREE 800-243-7428 From CmHitc^cut_QrFof_AMiiWncB. (2031 354-9375 Dept "■RESEARCH & ib 4) (DEVELOPMENT LTD 333 Litchfield Road, New Milford.CT 06776 Please send the items checked below: □ JAWS 16K RAM kit, No. 6416, S199.95.* D JAWS 16K RAM fully assembled, tested, burned in, No. 6416W, S229.95.* □ JAWS 32K RAM kit, No. 6432, (reg. price S329.95), SPECIAL PRICE $299.95.* □ JAWS 32K RAM fully assembled, tested, burned in, No. 6432W, (reg. price S369.95), SPECIAL PRICE $339.95* □ JAWS 48K RAM kit, No. 6448, (reg. price S459.95), SPECIAL PRICE $399.95* :.] JAWS 48K fully assembled, tested, burned in. No. 6448W. (reg. price S509.95), SPECIAL PRICE $449.95.* ' : JAWS 64K RAM kit, No. 64S4, (reg. price S589.95). SPECIAL PRICE $499.95. * □ JAWS 64K RAM fully assembled, tested, burned in, No. 5464W. (reg. price S649.95), SPECIAL PRICE $559.95.* □ Expansion kit, JAWS 16K RAM module, lo expand any of the above in 16K blocks up to 64K, No. 16EXP, $129.95.* 'All prices plus S2 postage and handling. Connecticut residents add sales lax. Total enclosed: S □ Personal Check □ Money order or Cashiers Check □ VISA □ MASTER CHARGE (Bank No ) Acct. No. Exp. Date Signature : Prim Name Address City State Zip H Send me more information parties. Bridge-bidding sequences are an example of a human protocol, although the complete protocol agreement between partners must be negotiated. Computers require precisely specified protocols. To encode meaning into a data stream, the concept of a frame must be introduced. A frame is a stream of bytes with a beginning-of-frame mark, a coded portion (which deter- mines the use of the data), the data, and an end-of -frame mark. To enable more reliable communications along a noisy channel, a checksum is ap- pended to the end of the frame; this is used by the receiver to verify that no bits have been dropped. Figure 3 presents the structure of the frames selected for this file-transfer applica- tion. Computer protocols, like human protocols, are those modes of behavior agreed upon between parties. Since each byte in a stream can assume any one of 256 values, a special technique is used to denote the beginning and ending of a frame. One particular byte is selected to be the data-link escape (DLE), to signify that the next byte is to be interpreted as either start of frame (STX) or end of frame (ETX). The receiver, when see- ing a DLE and a STX in series, knows that a frame has begun. When the DLE ETX pair is received, it knows that the end of frame has been reached and that the next 2 bytes con- tain the checksum. To preclude the appearance of a DLE STX or DLE ETX pair within the data portion of the frame, all DLEs in a data frame are doubled — that is, transmitted as DLE DLE. The receiver, seeing two sequential DLE bytes, simply discards one of them to restore the frame to its original length. The byte following the DLE STX is assigned the function of an operation code (ope) that is used to give mean- ing to the data portion of the frame. Four types of frames are defined: an address frame (hexadecimal 30), a data frame (hexadecimal 31), an acknowledge frame (hexadecimal 32), and a negative acknowledge frame (hexadecimal 33). These four frames represent the minimum set required to successfully get a file transferred from one computer to another in a simple, yet reliable fashion. One design possibility not used here would put the address field in the data frame so that the start-load ad- dress for each frame would be available just before its associated data. This would have eliminated the necessity for the address frame; however, it would require a buffer in the receiver equal to the length of the frame. The buffer would be used to hold the data until the checksum verified that the received data is perfect. If the data were not buffered, but was simply stored at the address specified, then an error in the address bytes would cause the data to be stored in the wrong portion of memory. With a separate address frame, the address will be verified as correct before the data arrives so that no receive buffering is required. Following receipt of the address or data frame, the receiver returns either an acknowledge (ACK) or a negative acknowledge (NAK) frame, thus in- dicating whether the frame received is perfect. The sender uses this informa- tion to decide whether or not to retransmit the frame. Thus, both computers must communicate to get the whole file transferred without error. Figure 4 illustrates the structure of each of the four types of frames. Data bytes corresponding to the code for DLE are doubled only in the data frame, which has variable length. This is unnecessary in the other three frames because they have a prede- fined length. The checksum is simply a 16-bit sum of all the bytes in the frame (ex- cept the first DLE and the trailing ETX). This provides an undetected bit-error rate which is adequate for this application. The frame structure is used only in file-transfer mode; in linking mode, each character is sent immediately; no error checking is considered to be necessary. The lowest level of protocol in- volves the hardware interface be- tween the two computers. In this ap- plication, the two computers are con- nected over an asynchronous bit- serial channel. This technique was selected for several reasons. A serial 258 April 1981 © BYTE Publications Inc NEECO Qt commodore 4008 (8K RAM - 40 Column) $ 795 16K "B" (16K RAM - 40 Column) 995 32K "B"(32K RAM - 40 Column) 995 32K "N" (32K RAM - 40 Column) 1295 4032 "B" (32K RAM 4.0 Basic - 40 Column) .... 1295 4032 "N"(32K RAM 4.0 Basic - 40 Column) .... 1295 4016 "B" (16K RAM 4.0 Basic - 40 Column) .... 995 4016 "N" (16K RAM 4.0 Basic - 40 Column) .... 995 2022 Tractor Printer 795 4040 Dual Disk (340 2.0 DOS) 1295 8050 Dual Disk (1 Meg, 2.0 DOS) 1795 8010 IEEE Modem 395 CZN Cassette 95 PET - IEEE Cable 40 IEEE-IEEE Cable 50 Why not buy from the best . INTERTEC DATA SYSTEMS 32K Superbrain (360K Disk Storage), CP/M* $2995 64K Superbrain (360 Disk Storage), CP/M* 3150 64K Quad Density Superbrain (700K Disk Storage), CP/M* 3995 ATARI COMPUTER JK. SYSTEMS ArARr m ATARI 400 (8K RAM) $499.00 ATARI 400 (16K RAM) 630.00 ATARI 800 (16K RAM) 1,080.00 ATARI 410 RECORDER 89.95 ATARI 810 DISK DRIVE 599.95 NEECO also carries all available ATARI software ALTOS COMPUTER SYSTEMS RAM DISK ACS 8000-IS 64K 250K $2840 ACS 8000-28 64K 500K 3500 ACS 8000-1 64K 500K 3840 ACS 8000-2 64K 1M 4500 ACS 8000-4 64K 2M 5600 ACS 8000-5 64K 1M 5990 ACS 8000-6 Mul2 - Multi-User (14.5 M-Winchester) 112K 1M 10,670 (29 M-Winchester) 112K 1M 11,870 ACS 8000-6 Mul4 Multi-User (14.5 M-Winchester) 208K 1M 11,960 (29 M Winchester) 208K 1M 13,160 fltcippkz computer ^==^W Authorized Dealer 16K APPLE II+ $1330 32K"II+ 1430 48K"II+ 1530 APPLE DISK w/3.3 DOS 650 APPLE DRIVE Only 495 APPLE III in Stock!! 128K, with Monitor and Info Analystpak 4740 EPSON PRINTER MX-80 80 Columns, 9x9 Dot Matrix Bidirectional Printing .. $645 Interface Cards 8140(RS-232) $55 8161 (IEEE 488) 55 8131 (Apple Card) 85 8230 (Apple Cable) 25 8220 (TRS-80 Cable) 35 PROFESSIONAL SOFTWARE WordPro I (8K) ...$29.95 WordPro III (40Col.)16K 199.95 WordPro I1I+ Enhanced Version 295.00 WordPro IV 80 Col., 32K 375.00 WordPro IV+ Enhanced Version 450.00 Multi-Cluster for Commodore Systems. Allows 3 CPU's (Expandable to 8) to access a single Commodore Disk. Multi-Cluster $795 (3 CPU's) Each Additional CPU $199 (up to 8) DIABLO 630 45 CPS, Letter Quality RS-232Port $2,710 Tractor Option 250 NEC Spinwriter 5530 (Parallel) $3055 5510 (Serial) 3055 5520 (KSR-Serial) 3415 TRACTOR OPTION ... 225 55 CPS Letter Quality High Reliability ITOH Starwriter Serial or Parallel $1995 FP 1500 25 CPs, Letter Quality NEECO Order Lines: (617) 449-1760 MON-FRI 9:00-5:00 VISA/MC Accepted Telex 951021 NeJd&MAS NEECO Order Lines: (617) 449-1760 I Circle 165 on inquiry card. BYTE April 19B1 259 NEW!!! THE * ELECTRIC MOUTH for SlOO, Elf II, Apple, TRS-80 Level II* From $99.95 kit Now — teach your computer to talk, dramatically increasing the interaction between you and your machine. That's right: the ELECTRIC MOUTH actually lets your computer talk! Installed and on-line in just - inutes, it's ready for spoken-language use in office, business, industrial and commercial applications, in games, special projects, R&D, education, secu- rity devices — there's no end to the ELECTRIC MOUTH's usefulness. Look at these features: * Supplied with 143 words/letters/ phonemes/ numbers, capable of producing hundreds of words and phrases. * Expandable on- board up to thousands of words and phrases (just add additional speech ROMs as they become available). * Four models, which plug directly into SlOO. Apple, Elf II and TRS-80 Level II computers. * Get it to talk by using either Basic or machine language {very easy lo use, complete instructions with examples included). * Uses National Semiconductor's " Digital ker" system. * Includes on-board audio amplifier and speaker, with provisions for external speakers and amplifier. * Adds a new dimension and excitement to pro- gramming; lets you modify existing programs and games to add spoken announcements of results, warnings, etc. * Installs in just minutes. Principle of Operation: The ELECTRIC MOUTH stores words in their digital equivalents in ROMs. When words, phrases, and phonemes are desired, they are simply called for by your program and then synthesized into speech. The ELECTRIC MOUTH system requires none of your valuable memory space except for a few addresses if used in memory mapped mode. In most cases, output ports (user selectable) are used, second d space f speed g Spoken Material Included! one eighteen m dollar inches numl iwo nineteen cancel down is df Ihree Iwenty case equal U <>■■ four 'n'rty cenl error kiln on five forty 400het1z lone feet left oul six BBS eoherlz lone flow less over seven s ' xI y 20ms silence fuel lesser parenthesis start i z eight seventy 40ms silence gallon limil percent slop j nine eighty nflms silence go low please than k tan !!' ne j^Lj I 60 ™ 5 silence gram lower plus ihe | eleven hundred azfJms silence great mark point time m twelve thousand camj greater meter pound Iry n thirteen million check have mile pulses up o fourteen zero comma high milli rale volt p fifteen again control higher minus re weight q sixteen ampere danger hour minuli; ready a r seventeen and degree in near right b s *"EJ/ JJ" ond "The EJeciric Mouth" are reg. trademarks 0/ Netronics R&D Ltd. "Apple" is a reg. trademark of Apple Computer Inc. "TRS-80 Level JJ" is a reg. trademark 0/ Tandy Corp. Continental U.S.A. Credit Card Buyers Outside Connecticut CALL TOLL FREE 800-243-7428 To Order From Connecticut Or For Technical Assistance, Etc., Call (203) 354-9375 NETRONICS R&D LTD.De P tB4 333 Litchfield Road, New Milford, CT 06776 Please send the items checked below: □ S 1 00 "Electric Mouth" kit soo.tir. □ Elf II "Electric Mouth" kit S99.95 U Apple "Electric Mouth" kit $1 10.95 D TRS-80 Level II "Electric Mouth" kit SI 19.05 Add $20.00 for wired & tested units. All plus $3.00 postage & in- surance. Conn res. add sales tax. Total Enclosed S D Personal Check D Cashier's Check/Money Order □ Visa □ Master Charge (Bank No. | Acct.No. Signature Print Name -Exp. Dale. Address City State 260 April 1981 © BYTE Publications Inc .JZhi_ SIGNAL LEVEL START BIT DO Dl D4 D5 D7 STOP BIT Figure 5: Serial transmission of data. When transmitting data between two computers on an asynchronous serial line, the data is transmitted 1 bit at a time with each byte of data (8 bits) framed by a start bit and a stop bit; a parity bit usually comes between the last data bit (D 7 ) and the stop bit but is omitted in this application due to the error checking already provided. Here, the byte being transmitted is binary 11010011 (read from right to left). COMPUTER A COMPUTER B SEND FILE SEND SERIAL LINE RECEIVE UJ £ z , UJ O W5 a £ z ° < ■x. < ° < ; < V> *: E a E * 2 U 5 < O OS UJ_ o s = o 3 s UJ < oz UJ or cc "SEN NAK' UJ Z i I 3 o 1 I % r RECEIVE SERIAL LINE SEND SEND FILE Figure 6: The interconnection of send and receive software modules. When computer A sends a data frame to computer B, the receive module of computer B tells its send module to transmit an ACK frame (if the data agrees with the checksum) or a NAK frame (if it does not). This acknowledge frame is received by computer A, which then informs its send module to transmit new data, or retransmit the previous frame, as necessary. channel uses few wires when a direct connection is possible. For longer distances, the link can be made by a telephone line and standard modems. Also, there are integrated circuits in- terfacing directly to the micro- processor that can handle this format very well. Figure 5 demonstrates how 8-bit bytes are transmitted along with their start and stop bits. To improve efficiency, no parity bit is used since the checksum provides error control. Software Description The software is organized into three cooperating modules: the send routine, the receive routine, and the command interpreter. The send and receive modules are used mainly for file transfer. The conceptual connec- tion of these two software modules in both computers is detailed in figure 6. The send routine of computer A sends to the receive routine in computer B, and vice versa. When the send module in A sends a frame, the receive module in B verifies the checksum and tells the send module in B to send either an ACK or a NAK back to A. The send module in B sends the ACK or NAK to A's receive module, which then in- forms A's send module that an ACK or a NAK was received. Thus, two flags are necessary for communicat- ing between the send and receive modules: one commanding "send ACK or NAK," and the other stating "received ACK or NAK." A "send file" flag to the send module of A in- itiates the file transfer. Note the symmetry. Because the send and receive sections in each computer are independent, and because they communicate by flags, the send output can be fed directly in- to the receive input in the same com- puter for test purposes during debug- ging. Files can be moved from one place in memory to another within the same machine, simulating the ac- tions of two coupled machines. The third module of code is the command interpreter, which is used to specify the source starting address, Text continued on page 266 QUALITY DISK SOFTWARE BACKED BY ON-GOING APPLICATIONS SUPPORT from SPECTRUM SOFTWARE APPLE II ® HOME FINANCE PAK I: Entire Series $49.95 ® © CHECK REGISTER AND BUDGET: This comprehensive CHECKING ACCOUNT MANAGEMENT SYSTEM not only keeps complete records, it also gives you the analysis and control tools you need to actively manage your account. The system provides routines for BUDGETING INCOME AND EXPENSE AUTOMATIC CHECK SEARCH, and BANK STATEMENT RECONCILING. CRTor printer reports are produced for ACTUAL EXPENSE vs BUDGET. CHECK SEARCH DISPLAY RECONCILIATION REPORTand CHECK REGISTER DISPLAY by month. Check entry is prompted by user-defined menus of standard purposes and recipient codes, speeding data entry and reducing disk storage and retrieval time. Six fields of data are stored for each check: amount, check no., date, purpose, recipient and TAX DEDUCTIBLE REMINDER. CHECK SEARCH routines allow searching on any of these data fields. Routines are also provided for CHECK SORT by date and check no.. DATA EDITING and Report Formats. Up to 100 checks/mo. storage S39.95 SAVINGS: Account management system for up to 20 separate Savings accounts. Organizes, files and displays deposits, withdrawals and interest earned for each account. Complete records shown via CRT or printer S14.95 CREDIT CARD: Get Control of your credit cards with this program. Organizes, stores and displays purchases, payments and service charges for up to 20 separate cards. Use for credit cards or bank loans. CRT or printer reports S14.95 UNIVERSAL COMPUTING MACHINE: $49.95 ® A user programmable computing system structured around a 50 row x 50 column table. User defines row and column names and equations forming a unique computing machine. Table elements can be multiplied, divided, subtracted or added to any other element. User can define repeated functions common to row or column greatly simplifying table setup. Hundreds of unique computing machines can be defined, used and stored, and recalled, with or without old data, for later use. Excellent for sales forecasts, engineering design analysis, budgets, inventory lists, income statements, production planning, project cost estimates-in short for any planning, analysis or reporting problem that can by solved with a table. Unique curser commands allow you to move to any element, change its value and immediately see the effect on other table values. Entire table can be printed by machine pages (user-defined 3-5 columns) on a 40 column printer. COLOR CALENDAR: $29.95® Got a busy calendar? Organize it with Color Calendar. Whether it's birthdays, appointments, business meetings or a regular office schedule, this program is the perfect way to schedule your activities. The calendar display is a beautiful HI-RES color graphics calendar of the selected month with each scheduled day highlighted in color. Using the daily schedule, you can review any day of the month and schedule an event or activity in any one of 20 time slots from 8:00 A.M. to 5:30 P.M. Your description can be up to 20 characters long. The system will also print out hard copies on your minimum 40-column printer. BUSINESS SOFTWARE: Entire Series $159.95®© MICR0ACC0UNTANT: The ideal accounting system for small businesses. Based on classic T-accounts and double-entry booking, this efficient program provides a ledger journal for recording posting and reviewing up to 1.000 transactions per month to any one of 300 accounts. The program produces CRT and printer reports covering: Transaction Journal Balance Sheet Accounts Ledgers Income and Expense Statement Includes a short primer on Financial Accounting. Requires 48K Ram $49.95 UNIVERSAL BUSINESS MACHINE: This program is designed to SIMPLIFY and SAVE TIME for the serious businessman who must periodically Analyze, Plan and Estimate. The program was created using our Universal Computing Machine and it is programmed to provide the folio wing planning and forecasting tools. CASH FLOW ANALYSIS SALES FORECASTER PROFORMA PROFIT & LOSS SOURCE AND USE OF FUNDS PROFORMA BALANCE SHEET JOB COST ESTIMATOR REAL ESTATE INVESTMENT INVENTORY ANALYSIS Price, including a copy of the Universal Computing Machine .... S89.95 TRS*80 © BUSINESS CHECK REGISTER AND BUDGET: Our Check Register and Budget programs expanded to include up to 50 budgetable items and up to 400 checks per month. Includes bank statement reconciling and automatic check search (48K) S49.95 ELECTRONICS SERIES: Entire Series $259.95 LOGIC SIMULATOR: SAVE TIME AND MONEY. Simulate your digital logic circuits before you build them. CMOS, TTL, or whatever, if it's digital logic, this program can handle it. The program is an interactive, menu driven, full-fledged logic simulator capable of simulating the bit-time response of a logic network to user-specified input patterns. It will handle up to 1000 gates, including NANDS, NORS, INVERTERS. FLIP-FLOPS. SHIFT REGISTERS. COUNTERS and user-defined MACROS. UP to 40 user-defined random, or binary input patterns. Simulation results displayed on CRT or printer. Accepts network descriptions from keyboard or from LOGIC DESIGNER for simulation S159.95 ®© LOGIC DESIGNER: Interactive HI-RES Graphics program for designing digital logic system. A menu driven series of keyboard commands allow you to draw directly on the screen up to 15 different gate types, including 10 gate shape patterns supplied with the program and 5 reserved for user specification. Standard patterns supplied are NAND, NOR. INVERTER. EX- 0R, T-FLOP. JK-FLOP, D-FLOP, RS-FLOP, 4 BIT COUNTER and N-BIT SHIFT REGISTER. User interconnects gates just as you would normally draw using line graphics commands. Network descriptions for LOGIC SIMULATOR generated simultaneously with the CRT diagram being drawn . $159.95 (A) MANUAL AND DEMO DISK: Instruction Manual and demo disk illustrating capabilities of both programs S29.95 MATHEMATICS SERIES: Entire Series $49.95 ® STATISTICAL ANALYSIS I: This menu driven program performs LINEAR REGRESSION analysis, determines the mean, standard deviation and plots the frequency distribution of user-supplied data sets. Printer, Disk, I/O routines S19.95 NUMERICAL ANALYSIS: HI-RES 2-Dimensional plot of any function. Automatic scaling. At your option, the program will plot the function, plot the INTEGRAL, plot the DERIVATIVE, determine the ROOTS, MAXIMA, MINIMA. INTEGRAL VALUE S19.95 MATRIX: A general purpose, menu driven program for determining the INVERSE and DETERMINANT of any matrix, as well as the SOLUTION to any set of SIMULTANEOUS LINEAR EQUATIONS $19.95 3-D SURFACE PLOTTER: Explore the ELEGANCE and BEAUTY of MATHE- MATICS by creating HI-RES PLOTS of 3-dimensional surfaces from any 3-variable equation. Disk save and recall routines for plots. Menu driven to vary surface parameters. Hidden line or transparent plotting . . . $19.95 ACTION ADVENTURE GAMES: Entire Series $29.95 ® RED BARON: Can you outfly the RED BARON? This fast action game simulates a machine-gun DOGFIGHT between your WORLD WAR I BI-PLANE and the baron's. You can LOOP, DIVE, BANK or CLIMB-and so can the BARON. In HI-RES graphics S14.95 BATTLE OF MIDWAY: You are in command of the U.S.S. HORNETS' DIVE- BOMBER squadron. Your targets are the Aircraft carriers. Akagi, Soryu and Kaga. You must fly your way through ZEROS and AA FIRE to make your DIVE-BOMB run. In HI-RES graphics $14.95 FREE CATALOG-AII programs are supplied on disk and run on Apple II w/Disk & Applesoft ROM Card & TRS-80 Level II and require 32K RAM unless otherwise noted. Detailed instructions included. Orders shipped within 5 days. Card users include card number. Add $1.50 postage and handling with each order. California residents add 6%% sales tax. Foreign orders add $5.00 postage and handling. SPECTRUM SOFTWARE 142 Carlow, P.O. Box 2084 Sunnyvale, CA 94087 FOR PHONE ORDERS: (408) 738-4387 DEALER INQUIRIES INVITED. Circle 166 on inquiry card. BYTE April 1981 261 ( IOINT J NO /CHARACTER ^\ ? ^/^ PRINT AND SEND CHARACTER Tyes PRINT "S."ON CONSOLE ( RETURN J KBSTATE= 1 f RETURN J KBSTATE= ( RETURN ) DECREMENT KBBUFF POINTER BY 1 f RETURN ) O PUT CHARACTER IN BUFFER; PRINT CHARACTER f RETURN J GET CHARACTER ACTER \ YES RETURN, f RETURN J CONVERT KBBUFF TO BINARY VALUE BYTECNT^VALUE XMITFILE = 1 KBBLOCK= 1 ( RETURN j SRCADDR* VALUE PRINT "D:" ON CONSOLE KBSTATE = 2 f RETURN J DESTADDR = VALUE PRINT "H:" ON CONSOLE KBSTATE= 3 ( RETURN J Figure 7: Flowchart for the command interpreter, IOInt. This routine gathers the information necessary to initiate the transfer of a given block of information between computers. An interrupt from the keyboard causes this routine to be executed (from the begin- ning) every time a key is pressed. The value of KBSTATE (keyboard state) causes the routine to ask for the starting address of the block to be sent (with the prompt "S:"). This is followed by a request for the destination address for the first byte (prompted with "D:"), and the number of bytes to be transferred (prompted with "#:"). Once this information has been given, the routine disables the keyboard from further input (KBBLOCK = l) and sets a flag that tells the software send module to begin sending the block of data (XMITFILE=1). 262 April 1981 © BYTE Publications lnc MAIN FRAME POMittf^ MICR OSM's ZEyS multiprocessor computer system delivers main frame performance for one to 64 users — performance impossible in a single processor micro! We start with the SI 00 bus and mount a Z80A as master processor to control the shared resources of disk and printer. Then we add a separate single board Z80A processor for each user (no bank switching!) so ZE|JS can grow any time from a single user to many with no changes in programs or files. And each user is independent of reset or program crash in other users. OSM's MUSE operating system — the Multi User System Executive — is many times faster than other leading operating systems. Each user owns a resident copy of MUSE so you don't wait for the bus or interrupt the master processor to do console I/O and applications code. MUSE finds files fast with a random directory access similar to random file access. And MUSE protects shared files from simul- taneous update to the same record by different users. We designed MUSE from the start for multi-user data base environments — yet MUSE is CP/M* compatible! Check the other multi-processors! Check the hardware! • S100 compatible master processor (4MHz Z80A, 32K dynamic RAM) for disk and shared printer control • single board processor (4MHz Z80A, 64K dynamic RAM), with I/O on board, for each user • serial and parallel ports on each user board support optional slave printer or other user devices • rack mountable enclosure built to highest industrial standards for reliable continuous operation • readily field expandable to any configuration from 1 user, 64K RAM, to 64 users, 4 Megabyte RAM • 2.4 Megabyte double sided dual density 8 " floppy disk • 26 to 96 Megabyte hard disk option • independent user processor reset directly from each keyboard Check the operating system! • all MUSE code written in Z80 native code (not 8080 code) for fast response • MUSE user operating system in 7K RAM on board each user processor reduces calls to the master processor • transfer of data between master and users via single Z80 block move command for highest speed • random directory search provides immediate file access • common file area for shared programs and files eliminates redundant files while individ- ual user file areas protect each user's private files • shared file update with record level lockout • spool file can be displayed, updated, reprinted • password security protects multiple user data bases • MUSE supports standard CP/M* word proc- essors, utilities, and languages: MBASIC, CBASIC, PASCAL, FORTRAN, COBOL, FORTH, C, PL/1, etc. Check the price! • under $15,000 for 2 user, 160K RAM, 26 Megabyte ZEyS system with dual floppy drives See OSM at the West Coast Computer Faire booth 1635, in San Francisco, April 3-4-5 CALL ys WE'RE SHIPPING ZEUS MICRO MAIN FRAMES! 'CP/NTTs a registered trade mark of Digital Research TODAY 408-496-6910 ex 40 2364 Walsh Avenue #4 Santa Clara, CA 95051 w /Kill 4^ m OSM Circle 167 on inquiry card. BYTE April 1981 263 ( XMITLOOP J I WAIT""! ' LOOP I XMITFILE=0 YES /RECDAClO = ? RECDACK=0 YES ■© RING BELL BLOCKKB=0 RETRANS=3 SEND ADDRESS FRAME: SEQUENCE IS: DLE.STX, 30,DESTADDR H ,DESTADDR L DLE,STX,CHECKSUM H , CHECKSUM L XMITLOOP WAIT FOR"ACK RECEIVED" SIGNAL (RECDACK=1) ©- YES WAITFLAG=0 XMITACK\ YES ( RETURN J SEND NAK FRAME XMITACK=0 0- RETRANS=RETRANS- 1 PRINT ERROR MESSAGE- TRANSMISSION OF DATA FRAME FAILED Figure 8: Flowchart for the send module. This routine, when activated by the condition XMITFILE=1, causes the computer to transmit a block of data in the form of an address frame, followed by a data frame. It waits in a loop until XMITFILE is set to 1, signaling that a block of data is ready to be transmitted. It then sends the address data frames, waiting after each for an ACK frame response from the receiving computer. If either frame is received imperfectly, the process begins again with the address frame. Soft- ware limits repetition to a total of three tries. All numbers used in this figure are hexadecimal. Also, the variables ADDRESS, BYTECNT, CHECKSUM, DESTADDR, INDEX, and SRCADDR are all 2-byte variables. The subscripts H and L refer to the high and low bytes, respectively, of a 2-byte variable. If the block to be transmitted is more than decimal 256 (hexadecimal 100) bytes long, it is transmitted in blocks of 256 bytes. On Flowcharting Interrupt-Driven Routines The perceptive reader may notice that the flowchart of figure 9 (on page 266) does not have a return or end block. Although it may not be immediately obvious, the same is true of the flowchart in figure 8. (The one return block that does exist is used only when the XmitLoop routine is returning from calling itself.) The reason for this and other seeming omissions has to do with the function of in- terrupts in the data-link routines. When the data-link software (see listing 1) is running, it is usually in the XmitLoop routine, repeating the wait loop marked in the flowchart of XmitLoop. (See figure 8.) If an interrupt comes from the keyboard, control transfers to the IOInt routine, flowcharted in figure 7, and returns to the routine that was executing before the inter- rupt. If an interrupt comes from the serial line, control transfers to some location within the Linelnput routine, but, instead of starting at the beginning of the routine (as is done with the IOInt routine), con- trol transfers to the instruction directly after the "bsr GetByte" (branch to GetByte subroutine) in- struction most previously ex- ecuted. (See figure 9.) This can be accomplished because the GetByte subroutine stores the return ad- dress in the variable ACIAState; it is this address that is jumped to upon a serial line interrupt (see routine IOInt in listing 1). 264 April 1981 © BYTE Publications Inc Circle 168 on inquiry card. SEND BEGINNING OF DATA FRAME; SEQUENCE IS: DLE, STX.31 YES INDEX* BYTECNT L INDEX = 100 ADDRESS — SRCADDR GET MEMORY BYTE, UPDATE CHECKSUM, AND SENDONE BYTE OF DATA FROM BODY OF DATA FRAME YES UPDATE CHECKSUM AND SEND SECOND DLE INDEX = INDEX -1 ADDRESS = ADDRESS+1 SEND END OF DATA FRAME, SEQUENCE IS: DLE, ETX, CHECKSUM H , CHECKSUM L XMITLOOP WAIT FOR "ACK RECEIVED" SIGNAL (RECDACK*!) BYTECNT=BYTECNT -100 DESTADDR= DESTADDR+100 SRCADDR= SRCADDR+100 I TOUGHEST IN TOWN FOR S-100's Monitor and control in wicked environments. Want to put your S-100 system to work in the world of computerized monitor- ing and process control? Dual Systems has all the boards it takes to do the job in the toughest factory environments. All are designed to function dependably in the real world of industrial control. All operate with Cromemco, North Star and other S-100 systems. A/D board. 12-bit precision. 32 single- ended inputs. Or 16 differential inputs. 25 /xs conversion time. Vectored interrupt. $635. Or $725 with 1 to 1000 gain trans- ducer amplifier. Works with our thermo- couple compensation board and our 4-20 mA input boards as well. D/A board. Four independent channels. 12-bit precision. Input is binary or 2's com- plement. Compatible with all existing I/O mapped software. $495. Drives our ampli- fier board which outputs 4-20 mA. CMOS RAM board. On-board battery back-up preserves data a year. 200 ns read/write time. Runs at 4 MHz. 8K bytes $590. 16K bytes $990. CMOS clock board. On-board battery back-up keeps clock running a year. New LSI chip carries date, hours, minutes and seconds. Read or write directly from I/O port. Vectored interrupt. $250. We also provide complete main- frame systems. OEM and dealer inquiries are invited. Contact Dual Systems Control Corp., Dept. B, 1825 Eastshore Hwy. Berke- ley, CA 94710. Phone (415) 549-3854. April 1981 © BYTE Publications Inc 265 (line INPUT J Text continued from page 260: the destination starting address, and the byte count. This code is activated by a control-F character depressed on the keyboard. The final carriage return sets the XMITFILE flag, which is polled by the background send routine. Command Interpreter Structure Figure 7 presents the flowchart for the command interpreter, IOInt, which is driven by interrupt signals received from the keyboard. Each character from the keyboard generates an interrupt, which starts the command interpreter. If the send module is currently sending a file, as evidenced by the relation "BLOCKKB > 0", then the character is to be ig- nored and is merely echoed as a bell. STORE BYTE AND INCREMENT ADDRESS GET CHECKSUMu ANDCHECKSUM L NO /tHECKSUrr- OK XMIT ACK=1 I RECDACK= -1 Figure 9: Flowchart for the receive module, Linelnput. Whenever an incoming byte on the serial line causes an interrupt to occur, control of the program transfers to a point within this routine just after the previous "get byte" request, and executes until another "get byte" request is encountered. Control then returns to the routine that was running before the serial line interrupt (usually the wait loop marked in figure 8) until another serial line interrupt causes the Linelnput routine to resume execution where it stopped. This routine stops for every byte of an ACK, NAK, address, or data frame. 266 April 1981 © BYTE Publications Ire Twoonthe-aisle. New Clipper Class style. No more middle seat in our brand new business section. We've redesigned Clipper Class completely So you'll never get stuck in the middle seat. Or by an elbow. You'll never be more than one seat from an aisle, either. Even if there's a full house. What's more, our Clipper Class seats are wider and more comfortable than ever before. In fact, they're the same seats selected for first class on the next generation of jets. The ones due for delivery around 1985. You see, Pan Am's new Clipper Class isn't just an upgraded economy section. It's w\ a totally separate part of the plane jr especially for business travelers. With all the extras you'd expect and a lot you wouldn't. New Clipper Class is now offered on selected Pan Am 747 routes. And by mid-year, we'll have it on our entire 747 fleet worldwide. Ask your Travel Agent, Corporate Travel Department or us about Pan Am's new Clipper Class. *»0S£ BYTE April 1961 267 The operation of the interpreter is a function of the state variable, KBSTATE. If the state is zero, the transparent mode case, the character is echoed locally and sent to the remote computer. Otherwise, the character is tested for being a carriage return (CR). The carriage return causes the keyboard buffer (which collects ad- dress or byte-count hexadecimal characters) to be converted to a binary value. If the character is a control-X, the interpreter mode is aborted and KBSTATE is returned to zero. If the character is a BS (backspace), the pointer into the keyboard buffer is decremented (after first checking for underflow). If none of the above is true, the character is checked for being a proper hexadecimal character and is then put in the keyboard buffer (after checking for overflow). The keyboard buffer holds as many as four hexadecimal characters, which is the largest buffer needed to specify a 16-bit address or a byte count. The sequence of characters echoed on the terminal following the carriage return, as well as the location of the binary value, are dependent on the current state of the interpreter. After each carriage return, the state is in- cremented to ensure that the correct control path is executed for each of the three parameters collected. Final- ly, the last carriage return after the byte count specification sets the BLOCKKB flag and the XMITFILE flag. The BLOCKKB flag prevents any keyboard characters from ap- pearing on the line during a file transfer. The XMITFILE flag tells the send module to begin sending the specified file. Send Routine Structure The send module, XmitLoop, is responsible for sending address, data, ACK, and NAK frames to the remote receive module. Figure 8 shows the flowchart for the program flow of the send routine. This routine operates in background mode, testing three flags to see if any work is pending. If the XMITACK flag is -1, a NAK frame is sent; if it is +1, an ACK frame is sent. If the RECDACK flag is not zero, and the send routine is waiting for an ACK or a NAK, then a return is made r ELIMINATE INTERACTING FLOPPIES, PRINTERS and processors with these AC power centers that have spike suppressors and filtered AC sockets. 69 8 sockets, 3 pairs individually filtered, spike suppressi MFJ-1107 1 2 sockets, one filter for all, spike suppression MFJ-1106 $>|Q95 49 1 2 sockets, spike suppression New MFJ multi-outlet AC power centers let you eliminate interaction of floppies, printers, memory, etc. caused by power linn coupling, and eliminate power line spikes that can cause memory loss, errors, and erratic operation. MFJ-1107 . varistors (from each line to ground and line to line) suppress spikes. 8 sockets (4 pairs), all 3-prong. RFI pi-filters on each line for each of 3 pairs of sockets iso- late equipment from each other and power line. Fourth pair is unswitched/unisolated. Lighted power switch. Pop-Out fuse. 3-wire 6 loot cord, 15A/125VAC. 1875 watts total. Rugged heavy-guage aluminum case. Black. Easy mounting slots. 18"L x 2-3/4"W x 1-7/8"H. MFJ-1106 , similar to 1107 but 12 sockets (2 unswitched), one filter for all, has spike pro MFJ-1105 lection, lighted switch, fuse. MFJ-1105 . same as 1106. less RFI filter. Order from MFJ and try it - no obligation. If not delighted, return it within 30 days lor refund (less shipping). One year unconditional g uarantee . Order today. Call toll free 800-647-1800. Charge VISA. MC or mail check, money order foi amount as indicated above plus $4.00 shipping each. Eliminate spikes and interaction, order now. CALL TOLL FREE . . . 800-647-1800 Call 601-323-5869 for technical information, or- der/repair status. Also call 601-323-5869 outside continental USA and in Mississippi. MET I ENTERPRISES, IWI W INCORPORATED Box 494, Mississippi State, MS 39762 J to the data transfer routine to com- plete the data or address frame transfer. (This will be explained in more detail later.) If the XMITFILE flag is non-zero, then file transfer begins. As explained earlier, the address frame is sent first so that no buffering in the receiver is necessary in case of an address error. Once the address is correctly received and acknowledged, a data frame is sent. If the data frame is acknowledged, the next address and data frames are sent, and the pro- cess is repeated. If a NAK frame is received, then the address frame received in error is retransmitted and verified before the data block is retransmitted. When sending either an address or a data frame, the send routine employs the same mechanism in waiting for an ACK or NAK. When the wait for an ACK or NAK signal is necessary, the send module XmitLoop calls itself by storing the return address on the stack and branching to the beginning of the routine. When the send routine finds that the RECDACK flag is set, control is returned to the proper loca- tion in the send routine via an RTS (return from subroutine) instruction. The RECDACK flag indicates whether a new frame should be sent or the old one retransmitted. A retransmission index is main- tained and decremented each time a frame retransmission is necessary, and no more than three retransmis- sions are allowed. (The number of retransmissions allowed is a parameter that is easily changed.) If more than three failures occur, an error message is typed on the sender's console and control returns to the transparent mode. When all of the file has been successfully transmitted, control returns to transparent mode and the keyboard is enabled. In data frames, data bytes that hap- pen to have the same hexadecimal value as the DLE code are doubled (repeated) so that a false end of frame is prevented; the receive routine drops the second DLE so that the data is received correctly. In the worst case, this has the effect of doubling the length of the frame. Receive Routine Structure The flowchart for the receive pro- gram, named Linelnput, is shown in figure 9. This routine handles the in- Text continued on page 286 268 April 1981 © BYTE Publications Inc Circle 169 on inquiry card. Why The People Who Know Use FMS-80 FMS-80, a data base management system, is the most powerful DBM program available to the microcomputer industry. Written in assembly language, it offers these features: • Operates on CP/Mf MP/M" or CDOS 00 systems. • User Definable: Screen formatting with up to 255 screens per data file, report generator, and menus capable of calling other CP/M programs or FMS-80 programs. • No restrictions to record size other than available RAM memory size. • Instantaneous data record inquiry on indexed data records. • Capable of selecting on any field or multiple fields with multiple selection criteria (fields do not have to be keyed). • Mathematical manipula- tion of numeric data fields (add, subtract, multiply and divide). • Capable of collect- ing information from multiple data files and generating a new data file or report. • All menu driven. • Capable of abstract- ing data from other pro grams written in other languages. • Available now (off the shelf). All these capabilities are available with the added plus of ease of programming See What Users of FMS-80 Have to Say: Mike Ketcham, systems consult ant and programmer for Management Information Systems: "FMS-80 allows me the flexibility of quickly creating programs for user applications. It is flexible, in that data can be entered in a form that the secretary recognizes and gen- erates reports that the manager requires. Also, the user- definable menus allow me to actually generate a menu from which the user can select, creating a true turnkey systeim'Tom Niccoli, Partner, Computerland of Phoenix: "FMS-80 is flexible enough to acquire data from an appli- cation program that was previously written and allowed me to generate the reports that my customer needed. It closed the deal for me. Considering its capa- bility, FMS-80 is one of the most cost-effective application pro- grams available today!' If you're continuously asked to do applications program- ming, and you don't have the time to do it in Basic, consider FMS-80. For additional information on FMS-80, contact Systems Plus, 3975 East Bayshore, Palo Alto, CA 94303. Phone (415) 969-7047." Systems Plus I Mike Ketcham. Managemenl Information Systems. Belmont, CA •TM of Digital Research, Pacific Grove, CA °TM of Croniemco, Sunnyvale, CA Circle 170 on inquiry card. BYTE April 1981 269 Listing 1: Software for data transfer between two 6800-based systems linked by a serial line. The software here consists primarily of a data-sending routine (labeled XmitLoop), a data-receiving routine (labeled Linelnput), and a command interpreter (labeled IOInt). All numbers preceded by a dollar sign ($) are hexadecimal numbers. Also, references to '0, '1, '2, and '3 are actually to the characters "0", "1", "2", and "3". These characters, when represented in ASCII, have values of hexadecimal 30, 31, 32, and 33 and are referred to in text and in flowcharts as such. Flowcharts 7 thru 9 correspond to the code given in this listing. rr*9i' rile eau Ppfti et x e«u H9B2 St X equ "(1710 7 bel 1 equ OH! 1ft *X equ P0P6 *F equ PP08 bs equ P90D C r equ 1 ft IOPt P eou F9Pn Ac 1 aCsM equ Fq01 Ac 1 aOat al eau F902 Ac i aCsr? equ F933 Ac 1 aOat a 2 equ OV5P SayeOpc equ ("051 Aci aSt at e equ ansa S re Arjdr equ 0056 DestAddr equ 0058 BvteCnt equ 0(?«5B n inVal eau a 050 KbPt r eau 01 rt S F KbBuif f equ 3362 KbF.nd eau 00.63 ChkSun. eau ;i?6^> ReedChk eau 0-lbA KbState equ 6 B RecdAc k eau i!06C Xmi t Ack eau 03 6 X m i t F i 1 e eau 006F W a i t F 1 a q eau H ; "6F Bl ockKb equ 7V-7S SaveSu" equ (.''17 7 XChkSum eau fl?79 Address eau $9ti $83 $82 7 M« 6 6 $d S 18 $f 900 $f901 Sf9P2 $f 903 $50 S51 $5U $"5b $S8 $5h $5d ISf $62 $b3 $b5 th.i $bb $bC $bd $6e *6< $75 $77 $79 die c^ar et x char 9 1 x char belt char control X control F backspace c a r r i age return I/O Interrupt vector Ac 1 a to terminal A c 1 a to modem place to save ope state of ac 1 a fsm ftp sou ret address ftp destination addr ftp byte count place to save number ot r into KbBuf f U char buffer end of hu f f er xmit checksum, recv side reed checksum, recv side state of kh handl e r f 1 aq - reed ac k flag - send ac k f 1 aq - send file flag - wait for ack/nack flag • blocks kb ac t i v olace to save checksum i« i 1 1 ed checksum r e c v store address 100 org I 1 (J 3 * Entry point 1000 1 PIP? 1005 1008 10PA 1000 1010 1013 1015 1018 101A 101C 101r- 1021 1022 1023 1025 1028 102A 1028 8b B7 B7 86 B7 H7 CE OF CE DF Bb CE bF !)8 4 4 26 CE DF 01 HE 03 F90tf F902 96 F q F902 lien 51 IIP? 18 06 0^6A P0 FA 005F 5D Start i n i ) o o o Ida s t a st a Ida st a s t a Idx St X 1 dx stx Ida idx cl r i nx dec bne idx stx nop cl i «3 Aci aCs r 1 Ac * aCsr2 »$9b Ac i aCsr 1 Ac i aCsr2 *InzAci a Aci aState •IOInt IOPtr *6 SKbSt ate x i n? 1 oop #KbBuf f KbPtr reset Acia's /6U, 8 bits, interr set up ac i a2 entry clear start the f 1 ags of area in* the buffer ptr * Background routine checks event entries 1P2C 102E 1030 1033 1035 9b 2b CE 9b 2b 6D 2A l?b7 6C PF Xm 1 t I oop 1037 D6 6ft 1 da a bne Idx 1 da a bne 1 da b Xmi tF 1 1 e I nzAddr *Nac kr r« Xm1 t Ack GoAc k RecdAck xmlt file event? ptr to Nack frame xmit ack/nack event? reed ack/nack event? Listing 1 continued on page 272 270 April 1981 © BYTE Publications Inc r v TRS-80® MODEL III OWNERS We think our disk system for expanding your capacity is just as good as theirs - and we know it costs much less . . . COMPLETE SYSTEMS AND COMPONENTS* TRS-80® MOD III SYSTEM wirh 2 disk drives SAVE $500 OFF LIST PRICE H,895 s 899 $ 649 ... J 279 $ 379 .. *359 $ 21.95 ... $ 59 .... >95 16K RAM, Model III Basic MTI DISK DRIVES for MODEL Internal Kits Disk Drive 1 Disk Drive 2 External Add-on Kits Disk Drive 3 Disk Drive 4 Model III DOS & Manual 16KRAMKir R5-232 Serial Interface PRINTERS Anadex 9500 M ,449 Microline 82 $ 849 Microline 83 $ 1 ,060 Centronics 779 M ,069 Centronics 700 M ,1 29 Dose 2 $ 649 Centronics 737 s 839 Epson MX-80 $ 579 Moiibu $ 2,093 Daisy Wheel s 1 ,799 Save 5% Off wirh Purchase of MOD III System or Disk Drive New low cost internal disk kit avail- able to expand your storage capability. With this kit, now, you may expand your Model III computer up to four MTI 40 track disk drives, giving 175,000 bytes of storage per drive for a total of 700K. The kit includes one 40 track disk drive, controller, power supply, cables, mounting hardware and installation documentation. Manufacturer Direct Price ONLY *649 fiR MICROCOMPUTER TECHNOLOGY, INC 3304 W. MACARTHUR, SANTA ANA, CA 92704 • PHONE (714) 979-9923 • TELEX #678401 TAD IRIN *Uses MTI Memory, Disk Drives & Components ® TR5-80" IS A REGISTERED TRADEMARK ^ OF TANDY CORPORATION VISA ALL PRICES CASH DISCOUNTED FREIGHT FOB FACTORY ASK FOR FREE CATALOG Circle 171 on inquiry card. BYTE April 1981 271 Listing 1 continued: 039 03B 030 03F 0 1 0A4 0A7 0A9 AAA 0AC 0AF 27 97 96 27 7F 1 7 39 2B CE C6 A6 BO 28 5A 2b D7 20 6B 6E FB 0C6ET 3 126,1 07 0F i tie 4 F7 6C D2 306D 58 7F DE 27 51 C6 83 37 C6 30 80 52 96 56 80 73 96 57 80 6F 80 59 33 to 2R 33 37 C6 31 80 3F 5F 96 58 26 3? 06 59 OF 5'J 37 A b g p 33 80 55 81 9.i 26 02 8D «F »8 5A 26 F0 80 35 33 00 2B 96 27 7A 7C 7C 2*1 5A 26 CE BD 0F 58 1 #7 x SendC har F rmLoop Xmi t Ack Xm i t Loop send nac k? send ac k 1 frame bvte count get bvte send out clear the pvent * Routine for sending Address frame I nz Add r GoAddr * there c! r ldx beg Ida b psh b Ida b bsr 1 da a bsr 1 da a bsr bsr is a wait pul b t st a bmi Xmi tF i le Byt eCnt LastB! k #3 clear c hec k flag for null i ndex ret ransm i ss i on save i t opcode byte send dl e, st x, ope send out addr bytes *»0 SendHdr Dest Addr UpdtChk Oest Addr* 1 UpdtChk SendTl send d1e,etx,cc - wait for ac k/nac k he re get ret pans i ndex check ack/nack flag RetryBlk branch if ack * Routine G o F i l e Skipl.d SendBy t es F i n o U n there RetryBlk F r ror for PSh Ida bsr Cl r b 1 da a bne Ida b Idx psh h 1 da a pu 1 b bsr cmp a bne bs r i nx dec b bne bsr is a wait pu 1 b t st a hm i Ida a beg dec i nc i nc bra dec b bne 1 dx Isr sending block of data b b SendHdr By t eCnt SkipLd Byt eCnt+1 S rcAddr UpdtChk #dle FinOoub UpdtChk save retrans index opcode send dl e, st x, opc in* byte count index chk upper hyte < 256 bytes left save i t get byte restore update checksum, send check for die update checksum, send check byte count SendBy t es SendTl send dle,etx,cc ■ wait tor ack/nack here get ret rang i ndex check ack/nack flag check for failure check for done Ret rvBl k ByteCnt LastBl k ByteCnt Oes t Addr SrcAddr InzAddr decrease i nc rease i nc rease bv by by 256 256 256 bytes bytes byt es GoAddr *Error M sg print error msq u t T e x t Listing 1 continued on page 274 272 April 1981 © BYTE Publications Inc LOWEST PRICE - BEST QUALITY NORTH STAR North Star Horizon 2 2-5 1 /4 Disk Drives 32K Double Den Factory assem. & tested Factory guaranteed List 3095 only $2274 POWERFUL NORTH STAR BASIC FREE SUPERB FOR BUSINESS & SCIENCE FACTORY ASSEMBLED & TESTED LIST ONLY HORIZON-1-32K-DOUBLE DEN $2695 $1980 HORIZON-2-32K-QUAD DENSITY 3595 2674 HORIZON-2-64K-QUAD + HARD DISK 9329 7149 HORIZON RAM ASSM 16K=$389. 32K = $579 HORIZON RAM KIT SALE! 16K = $314 32K = $469 HORIZON DISK DRIVE SALE DOUB DEN SAVE! 315 NORTH STAR HARD DISK 18 Mb 4999 $3929 PASCAL-PLUS 14,1 8 OR 36 DIGIT PRECISION 249 SUPERBRAIN ZENITH SUPERBRAIN QD 64K List $3995 only $2995 Z-89 48K List $2895 only $2299 TERMINALS Z-1 9 $725 INTERTUBEIII om y $725 DIP-81 PRINTER om y $395 MICROTEK $675 NEC PRINTER $2569 TRACTOR, THIMBLE, RIBBON InterSystems ITHACA INTERSYSTEMS 2A List $3595 You Pay Only Z-80A CPU 4 MHz 64K Dynamic RAM Front panel V I/O — with interrupts FDCII Disk Controller 20 slot motherboard $2795 PASCAUZ + THE FASTEST PASCAL $375 GET READY FOR ITHACA'S Z-8000 8086 16 BIT CPU & SUPPORT CARD SEATTLE $575 MORROW 8" DISK DISCUS 2D + CP/M® 600K ONLY $938 DISCUS 2 + 2 + CP/M® 1.2 MEGA B. $1259 ADD DRIVES 2D = $650 2 + 2 = $975 2D-DUAL + CP/M® ONLY $1555 MORROW HARD DISK 26,000,000 BYTES!! LIST $4995 ONLY $3995 CP/M® IS INCLUDED! SAVE ON MEMORY AND PROGRAMS SYSTEMS MEMORY 64K AST 4mHz $599 SYSTEMS MEMORY 64K BANK SELECT $789 CENTRAL DATA 64K RAM $599 ITHACA MEMORY 8/1 6-bit 64K $845 SEATTLE MEMORY 8/16 BIT 16K 4Mhz $275 SSM KITS Z-80 CPU $221 VIDEO BROV83 4Mhz $412 ANADEX PRINTER DP-9500-1 $1349 CAT NOVATION MODEM $169 TARBELL DISK CONTROLLER DD $445 ECONORAM2A8KASSM $179 NSSE 1-22 & P01 TERRIFIC PROGRAMS ONLY $10. EACH NORTHWORD 294 MAILMAN 234 INFOMAN $364 TARBELL COMPUTER-PHONE RCA-COSMAC VP-1 1 1 99 RCA-COSMAC VP-711 $199 COLOR! RAINBOW 385 SPECTRUM $289 EZ-80 Machine Language Tutor $25 EZ-CODER Translates English to BASIC $71 ECOSOFT FULL ACCOUNTING PKG $315 BOX OF DISKETTES $29 SECRETARY WORD PROCESSOR The Best! $99 TEXTWRITER III Book Writing Program $112 GOFAST NORTH STAR BASIC Speeder Upper $71 Which Computers are BEST? BROCHURE FREE North Star Documentation refundable w/HRZ $20 AMERICAN SQUARE COMPUTERS BEATS ADV. PRICES square American [0] Computers 91 9-889-4577 KIVETT DR. JAMESTOWN N.C. 27282 91 9-883-1 1 05 CP/M is a registered trademark of Digital Research, Inc. Circle 172 on inquiry card. BYTE April 1981 273 Listing I continued: 10B2 fi6 P7 LastBlk Ida a «beH ring the bell 10BU 80 H\ nsr SendTerm send bell to term 10B6 07 6F sta b BlockKb unlock the kh 1 WBfl 20 9E F4n2 bra Fin4 end of file xfer * Subroutine which sends out dle.stx, unci in? checksum 10BA 86 90 SendHdr Ida a *dle die char 108C 80 2C bsr SendChar send die lPlRE IF c 1 r a 10BF 97 77 sta a XChkSum In? checksum 10C1 97 78 sta a XChkSum+1 1BC3 86 8? 1 da a * s t x 10C5 8D 18 bsf UpdtChk send stx 10C7 17 tba 10C8 80 IS bsr UpdtChk send opcode 10CA 39 rts * Subroutine whi c K sends out dle,etx»ccl#ce2 * and sets up wait for ack/nack 10CB 8b 9a SendTl Ida a «dle 1 C 9 7 6 (-. sta a wgitHaq indicate waiting ack/nack 10CF 80 0£ bsr UpdtChk send out die 1001 86 83 Ida a «etx 1003 80 IS bsr SendChar send out etx 1005 96 77 Ida a XChkSum 1007 80 11 bar SendChar send high bytp 10D9 96 78 Ida a XChkSum+1 10DB 80 00 bsr SendChar send low byte 10DO ?£' 09 bra Fin2 go to idle 1 non 10OF 56 UpdtChk PSh a 10E!l 9B 78 add a XChkSgm+1 10E2 2 4 «3 bec SkpH 1 E 4 7CP; , 77 in C XChkSum I WE 7 97 78 SkpH sta a XChkSum+1 10F9 3? pul a 10EA 37 SendChar psh r> save it 10FB F6 F90? Ida b AciaCsr2 aet status 10tE C a ? 2 and h a 2 tent for ««it reaOV 10F0 27 F9 beg SendChar+1 10F2 H7 F9B3 sta a AciaData? 10F5 33 Pul b restore req 10F6 39 rts 10F7 r 6 F 9 1- 1 SendTerrr Ida b AciaCsrl aet status 10FA C4 02 a"d b «2 test for transmit rn v 10FC 27 F9 bea Send Term wait for readv 10FF 87 F901 sta a AciaDatal 1101 39 rts * Entry Doint for the I/C interrupt 1102 &6 F902 IOInt Ida a AcieCsr2 aet status 1105 2A 07 bpl Kblnt chk for ac i a interr 1107 B6 F903 Acia2Int Ida a AciaData2 get l|ne data 110A DE 51 ldx AciaStete 110C 6E 00 j mp x go to ACIA routine 110E 86 F90) Kblnt Ida a AciaDatal get kb data 1111 By 7F and a #$7f kill parity bit 1113 D6 6F Ida b BlockKb Chk if sending file 1115 27 05 beg ChkCl i 1117 86 07 OutBell Ida a «bell 1119 80 0C OutTerm bsr SendTerm send char to term 1 1 1 B 3B rti return 111C D6 6A ChkCli Ida b KbState I I IE 26 13 bne CI I 1120 81 06 emp 3 #*F 1122 27 05 bea StartCl i 1124 8D 01 bsr SendTerm send char to term 1126 8D C2 bsr SendChar 1128 3B rti return 1129 CE 1278 StartCl i Idx #SrcT x t output S? Listing 1 continued on page 276 274 April 1981 © BYTE Publications Inc 32K Board Pictured Above Why Not the Best? From The Dynamic RAM Company. 2MHz 4MHz 16K— $249 $259 32K— $375 $395 48K— $500 $530 64K— $625 $665 We have now been shipping our 2MHz dynamic RAM boards for over two years. Hundreds of 4MHz boards have been going out every month since early 1979. Our reliability is proven in the thousands of systems which contain our board. Many quality- minded systems houses across the country and overseas are using our boards for their equipment. Our prices still beat all. Despite rising 1 6K memory chip prices (at least from reputable suppliers), Central Data continues to give you the best buy in memory today. Nobody offers a board with a capacity of 64K, assembled, tested, and guaranteed for a full year at the price we do. Circle 173 on inquiry card. Deselect around PROMs. Our boards have the important deselect feature which lets you overlap any fixed memory in your system with no interference. Our features make the board easily used and expanded. You address our boards on 1 6K boundaries with mini-jumps (small shorting plugs that slide over wire- wrap pins) near the top of the board for easy access. If you want to expand your board after you have purchased it, all that you need to do is add memory. We can supply you with expansion packages ($1 50-2MHz, $160-4MHz) which include eight RAMs that you can depend on as well as two mini-jumps for addressing. And of course, our board never generates wait states. Low power consumption keeps your computer running cool and reliable. The total power consumption of our 16K board is typically less than 4 watts ( + 8V @ 300ma, + 1 6V @ 1 50ma and -16V @ 20ma). Boards with additional memory typically increase power consumption only 1 watt per 1 6K! Standard S-100 Interface. Our board is designed to interface with any standard S-1 00 CPU. All of the timing of the board is independent of the processor chip, and the board is set up for different processors by changing two plugs on the board. Call or write us today. That will guarantee a fast response with more information on the board. Or make an order — you'll probably have the board in two weeks! If you're interested, also ask for a catalog on our Z8000 16-bit processor board designed for the MULTIBUS. All of these products are available to your local dealer, also. Central Data Corporation, 713 Edgebrook Drive, PO Box 2530, Station A, Champaign, IL 61820. (217) 359-8010 Central Data BYTE April 1981 275 Listing 1 J12C 11 2F 1132 1133 1135 1137 1139 1 13B 1130 113F 11UC? 1142 1 t«4 1116 11^8 111A 1 14C llflE 115? 1152 115a 1157 1159 1156 H5C 115F H5F 1161 1 162 1 16« 1167 1169 U6B continued: 8D HB2 7C «P»6A 3B 81 27 81 27 81 27 36 8tf 2B fl! 2F 81 2B 81 2E ea Dfc" 8C 27 A7 08 OF 32 20 32 20 CE 8D 97 CE 0D 46 18 29 32 ID HA 31 15 36 11 27 5D 51063 H8 (53 5D BS B3 1275 49 6A 005F CI i CharDK BadChar Cancel InzPt r i nc pti emp beq Cffp bea emp bea pen. sub bm1 Cmp ble emp bml cup bgt sub ldx CPU bea st a 1 nx stx pul bra pul bra ldx bsr st a ldx OutText KbState #CP Convert **X Cancel tfbs BackUp *$30 BadChar «9 CharOK tt$31 BadChar »$36 BadChar #$27 KbPtr #KbEnd+l BadChar x KbPt r Out Term OutBel 1 *CRLF OutText KbState SKbBuf f return check for CR Check for ctrl x check for backspace save for display check for valid hex char check for overf 1 ow qet original char echo for dl 9pl av pull off stack out put a c r# If cl r KbState Listing 1 continued on page 278 To Place An Order From Outside Texas 1-800-231-3680 Questions & Answers & Orders Texas 1-713-392-0747 M ARYMAC INDUSTRIES, IN C. ( Radio /hack ) Store #Q-189 AUTHORIZED SALES CENTER BRAND NEW IN CARTONS DELIVERED. Marymac Industries owns & operates Radio Shack® dealership in Katy, Texas. Warran- ties will be honored by all company owned Radio Shack 8 stores, & participating franchisees and dealer authorized sales centers. Save State Sales Tax. Texas Residents Add Only 5% Sales Tax. Open Mon.-Sat. 9-6 . We pay freight and insurance. No extra charge for Master Charge & Visa. Call us for reference in or near your city. Ref: Farmers State Bank, Brookshire, Texas. Write or visit us at, 21969 Katy Fwy, Katy (Houston), Texas 77450. WE OFFER ON REQUEST Federal Express Houston Intercontinental Airport Delivery U.P.S. BLUE References from people who have bought computers from us probably in your city ED McMANUS 10% 15% OR MORE Model III In stock TR8-80 Modal II and III No Tax on Out of Texas Shipments! WE ALWAYS OFFER NO extra charge for Master Charge or Visa We always pay the freight and insurance Toll free order number Our capability to go to the giant Tandy Computer warehouse 5 hours away, in Ft. Worth, Texas, to keep you in stock. JOE McMANUS RadM Jhaek In Stock 276 April 1981 © BYTE Publications Inc Circle 174 on inquiry card. MODEL II $ DISCOUNT $ TRS-80®. MODEL RA301 26-4002 64K 1 Drive $3440.00 26-4160 1 Drive EXP $1035.00 26-4161 2 Drive EXP 1575.00 26-4162 3 Drive EXP 21 15.00 26-4501 Gen. Ledger 180.00 26-4502 Inventory 180.00 26-4503 Payroll 360.00 26-4554 Acct. Rec 180.00 26-4701 Fortran 270.00 26-1157A Daisy Wheel. . .2290.00 26-1158 Daisy Wheel II. . .1799.00 COMPUTER SPECIALISTS 26-1 155 Quick Printer II $187.00 26-1 145 RS-232 Board 84.00 26-1140 "O" K Interface 249.00 26-1141 "16" K Interface 359.00 26-1 142 "32" K Interface 469.00 26-1160 Mini Disk - Drive 419.00 26-1 161 Mini Disk - Additional 419.00 26-1154 Lineprinter II 699.00 26-1 165 Line Printer V 1710.00 26-1 159 Lineprinter IV 859.00 26-1 166 Line Printer VI 1080.00 26-1563 Scripsit - Disk 79.00 26-1566 Visicalc 83.00 26-1562 Profile 72.00 26-1061 4KI $630.00 26-1062 16K III 888.00 26-1063 32K III 2-Drives, RS232 2225.00 COLOR ALL OTHER R.S. SOFTWARE FURNITURE, STANDS, CABLES AND ACCESSORIES AT DISCOUNT FROM CATALOG PRICE. 26-3001 4K $360.00 26-3002 16K 540.00 26-3010 Color Video 360.00 26-1206 Recorder 54.00 26-3008 Joysticks 22.50 CEriTROniC5 Fast 100 CPS Centronics 730 Printer 577.00 Text Quality Centronics 737 Printer 737.00 Novation Cat Modem. .$149.00 CCA Data Management System 72.00 Adventure Games Games 1-9 each 14.00 Q Acorn Software Products, Inc. Model II Cobol Compiler $360.00 Cobol Run Time Package $36.00 Pocket Computer ■jv • • • " ' *' fgtpc ioono ! CD CO G3 CD CO S3 S3 G3 C3D aaaaa 26-3501 1 .9K P.C $225.00 26-3503 Cassette l/F 45.00 14-812 Recorder 72.00 GAMES: Alien Invasion $9.00 Stock Market 9.00 Star Trek 9.00 Block Em 9.00 Ting-Tong 9.00 UTILITIES: System Savers 14.00 EDUCATION: Language Teacher 1 8.00 FREE: COMPUTER CATALOG UPON REQUEST 1-800-841-0860 Toll Free Order Entry MICRO MANAGEMENT SYSTEMS, INC. No Taxes on Out Of State Shipments Immediate Shipment From Stock on Most Items DOWNTOWN PLAZA SHOPPING CENTER 115CSECONDAVE.S.W. CAIRO, GEORGIA31728 (912) 377-7120 Ga. Phone No. -TRS-80 It a reglitered trademark of th* Tandy Corp. R.S. 90 Day Limited Warranty F-48 Form Provided Largest Inventory In the S.E. U.S.A. Circle 175 on inquiry card. BYTE April 1981 277 Listing 1 116E 1170 1171 1173 1176 1178 1179 117B 1170 1180 U82 U8U 1186 1188 118A 118C 118E 1190 1192 1195 1197 1199 1198 119D 11A0 11A2 11*5 11A7 11A9 1 1 AC 11AE 1 1BPI continued: DF 5D 3B DE 5D 8C 005F 27 9F 09 DF 5D 20 9C CE 005F 8D 3A 97 58 80 36 97 5C DE 5B 96 6A 81 01 26 07 DF 5a CE 127D 20 09 81 0? 26 0C DF 56 CE 128? 8D IP 7C 0f"6A 20 Ca DF 58 7F 0PI6A 97 6D 97 6F 2<* B9 BackUp Convert Trv2 CM spText Trvi stx rti ldx cpx bea dex stx bra ldx bsr st a bsr st a ldx Ida cmp bne stx ldx bra cmp bne stx ldx bs i" i nc bra stx cl r st a st a bra KbPt p KbPt r *KbBuf f OutBel 1 KbPt OutT «KbH Bvte BinV Byte BinV BinV KbSt *1 Trv2 SrcA #Des D i sp #2 Trv3 Dest #RCn OutT KbSt InzP Byte KbSt Xmi t Bloc InzP r epm uf f al al + 1 al ate ddr tTxt Text Addr tTxt ext ate t r Cnt ate File kKb t r ini pt r return check for underflow deer KbPtr point at buffer qet a byte Put in ins byte qet a byte qet binary nu»be r check fsm state display D s display » « s ave byte count set send file event 1 ock the kb 11B2 11B4 A6 27 13 Out Text Ida bea Retnfa qet char Listing 1 continued on page 280 Big Savin g s On Atari & PET! No Risk - No Deposit On Phone Orders - Shipped Same Day You Call - C.O.D. or Credit Card * On all in stock units Atari® 800 List $1080 only $759 ATARI* 400 8K 400 16K . 410 Recorder 815 Disk 810 Disk 822 Printer 825 Printer 830 Modem 850 Interface Module CX852 8KRAM CX853 RAM CX70 Light Pen CX30 Paddle CX40 Joystick CX8100 Blank Diskettes (5/box) 62 1199 489 359 779 159 179 94 149 64 18 18 22 CXL4104 Mailing List $17 CX4107 Biorhythm 13 CXL4007 Music Composer 45 CX41 10 Typing 20 CX4101 An Invitation to Programming 17 CXL401 5 TeleLink'" 20 CXL4004 Basketball S 30 CX4105 Blackjack 13 CXL4009 Chess 30 CXL401 1 Star Raiders'" 45 CX411 1 Space Invaders 18 CXL4006 Super Breakout" 30 CXL4010 3-DTic-Tac-Toe 30 CXL4005 Video Easel" 30 Please Call Between 11AM & 6PM (Eastern Standard Time) (800) 233-8050 To Order: Phone orders invited (800 number is for order desk only). Or send check or money order. Equipment shipped UPS collect. Pennsylvania residents add 6% sales tax. Add 3% for Visa or MC. Equipment is subject to price change and availability without notice. Computer Mail Order 501 E. Third St. Williamsport, PA 17701 £* commodore 4032N $1090 CBM 2022 Printer. 4032B. 8032... NEW- VIC-20 1090 1499 $299 CBM 4040 Drive. CBM 8050 Drive. CBM C2N Drive . PET-IEEE Cable.. IEEE-IEEE Cable. 675 1090 1420 87 37 46 Software E186 279 WordPro 3 (40 col.) WordPro 4 (80 col.) WordPro 4 Plus (80 col.) 339 Visicalc - Apple 122 Visicalc - Atari 163 Visicalc -PET 163 Commodore Tax Package 399 Microtek - for Atari Microtek 16K RAM ... 99.95 Microtek 32K RAM ...189.95 Disks Sycom 5 1 A" Single Density Box of 10 $29 Maxell 5'A" Floppy- MD1 Single Density Box of 1 34 MD2 Double Density Box of 10 44 Printers Trendcom 200 489 Epson MX-80 539 Commodore Tally 8024... 1679 (717) 323-7921 278 April 1981 © BYTE Publications Inc Circle 176 on inquiry card. Circle 177 on inquiry card. 16 BIT 8086 MICRO SYSTEM Tec ■ 86 ™ Basic ■ 86 ™ CP/M - 86 ™ IEEE S- 100 Bus - Available Now Complete system up and operating 8086 System with Dual Floppy Disks Available Now for only $3990 CP/M-86™ only $250 Basic -86™ only $350 Tec-86 / 8086 System $3990 ■ Complete 8086 System for CP/M-86 7 CP/M-86 Available Now - $250 • IEEE 696 S-100 Compatible • 5 MHz 8086 CPU (Optional 4 or 8 MHz) • Vectored Interrupts • 24 Parallel I/O lines (three 8 bit ports) • Two RS-232 Ports • Baud rates from 50 to 19200 baud • Independent baud rate generator for each serial port • 32 Kilobytes of static RAM (Expandable) • ROM boot for CP/M- 86™ • Dual 8-inch Shugart floppy disks with controller • Attractive, all metal desk top enclosure Optional 64K Dynamic RAM - Available Soon Basic-86™ Available Now EC RR eqistered tradeMark ■ Microsoft Data Acquisition Systems and Video Digitization Systems Available 23414 Greenlawn • Cleveland, OH 44122 TECMAR, INC. (216)382-7599 CPM" registered tradeMark • Digital Research Listing 1 continued: 1B6 BO 1 OF 7 1B9 08 1 B A 20 Ffc 1BC 1BE 1BF 1C(5 1C1 1C2 1C3 lCu 1C6 1C7 1C8 1C9 1CA 1CD 1CF 1D1 10*1 \Ob )D8 ID* IDC 1DD IDF 1E1 1E3 U5 1E7 If A6 H8 48 Set ; J*ck sta b F i r.3 bra a Dat aF rm »•? VerChk #'3 VerChk ErrMack GetBvte Address GetBvte Address* 1 GetBvte GetBvte ChkSum Sa veSum GetBvte RecdChk GetBvte RecdChk+i *1 RecdChk SaveSum SkpCrt SaveOpc *2 SendAck check for ack frame check for nack frame bad f pa»e get upper addr bvte get lower addr bvte aet die net et x save the checksum get upper checksum get lower checksum 1 => Ack -1 a> Nack get opcode Ignore bit error -> reed Nack get opcode check for reed Ac* SetRAck SaveOpc SetRAck - 1 s> reed Nack nop, 1 s> reed Ack, -1 s> reed Nack RecdAck Linelnput Listing 1 continued on page 284 Combine accurate flight characteristics with the best in animation graphics and you'll have SubLOGIC's A2-FS1 Flight Simulator for the Apple II SubLOGIC s A2-FS1 is the smooth, realistic simulator that gives you a real-time, 3-D, out-of-the-cockpit view of flight. Thanks to fast animation and accurate repre- sentation of flight, the non-pilot can now learn basic flight control, including take-offs and landings! And experienced pilots will recog- nize how thoroughly they can explore the aircraft's characteristics. Once you've acquired flight proficiency, you can engage in the exciting British Ace 3-D Aerial Battle Game included in the package. Destroy the enemy's fuel depot while evading enemy fighters. Computer and aviation experts call the A2-FS1 a marvel of modern technology. You'll simply call it fantastic! Special Features: • 3 frame-per-second flicker free animation • Keyboard or joystick input on cassette or disk! s 25 00 on cassette, usable on all systems (16Kmemory required) $ 33 50 on disk, usable on DOS 3.2, DOS 3.3, or Language System (32K memory required) See your dealer or order direct. For direct order, include $1.25 and specify UPS or first class mail. Illinois residents • add 5% sales tax. Visa and Mastercard v. accepted. ^ Present cassette users may send back their cassette (bul not the manual), along with $10 (first class shipping included), and receive the disk version. *L0GIC Communications Corp. BoxV, Savoy, I L 61874 (217)359-8482 Telex: 206995 282 April 1981 © BYTE Publications Inc Circle 180 on inquiry card. Pascal from beginning to... The BYTE Book of Pascal Edited by Blaise W. Liffick This newly reprinted edition, compiled from articles, language forums, and letters from BYTE Magazine, provides a comprehensive introduction to Pascal. In addi- tion this book contains important software, including two versions of a Pascal compiler — one written in BASIC and the other in 8080 assembly language; a p-code interpreter written in both Pascal and 8080 assembly languages; a chess playing program; and an APL interpreter written in Pascal. $25.00 Hardcover pp. 342 ISBN 0-07-037823-1 ,.•"•' ~S \ ^f \ Beginner's Guide for the UCSD Pascal System Now in its 3rd printing, written by the originator of the UCSD Pascal System, this highly infor- mative book is an orientation guide to the UCSD Pascal System. For the novice, this book steps through the System, bringing the user to a sophisticated level of expertise. For the ex- perienced, the guide is an invaluable reference tool for creating advanced applications. The UCSD Pascal Software Systems, available from SofTech Microsystems Inc, 9494 Black Mountain Road, San Diego CA 921 26, is a complete, general-purpose software package for users of microcomputers and minicomputers. The package offers several in- teresting features including: • Programs which may be run without alteration on the General Automation or DEC Jf ^ i< 4? Toll Free # 1-800-258-5420 I'inil Please send D □ copies of The BYTE Book of Pascal copies of Beginner's Guide for the UCSD Pascal System Name Title Company Street City State/Province Code □ Check enclosed in the amount of $ D Bill Visa □ Bill Master Charge Card No. Exp. Date . Add 7 5 nop, 1 => xmit Ack, -1 => xmit ^ack 122E 20 9A bra Unelnput 1 23P1 flD ID DataFrm bsr GetBvte 1232 81 90 cmp a »dle check for doubled die 123a 27 09 beo ChkDble 1236 DE 79 OkOble 1 dx Address 1238 A7 gip sta a x store byte 123A 08 inx 123B OF 79 stx Address 123D 2*3 Fl bra DataFrm 123F 80 0E ChkDble bar GetByte throw away first die 1241 Si 99 cmp a #dle 1213 27 Ft beo OkOble 1215 8l 83 cmo a *etx check for frame end 1217 27 BA beq Verify frame error 1219 86 FF F-rrNeck Ida a *-l send Mack event 121B 97 6C Sta a XmitAck 12«D 2a OB bra Fin3 * Exit routine which saves the return address, * undates the checksum, and does rti 121F 30 GetByte tsx 1250 EE "0 Idx x qet entry point 1252 OF 51 stx AciaState save return aodess 1251 3) ins 1255 3i ins get off stack 1256 9B 61 add a ChkSum+j 1258 2u 03 bcc SlepUpper 125A 7C 0063 inc ChkSum 125D 97 61 SkpUpner ata a ChkSum+1 125F 3B rti return 1260 90 AckFrm fcb dl e» st x , • 2 , d 1 e, e t x, 1 , S« 'J 1261 82 1262 32 1263 90 1261 83 1265 01 1266 1U 1267 9? NackFrm fcb rtl e, st x, ' 3» dl e# et x, 1 , S«5 1268 82 1269 33 126* 90 126B 83 126C 01 126D 15 126E 20 ErrorMsn fee / Failed/ 126F 16 1270 61 1271 69 1272 6C 1273 65 1271 61 1275 00 CRLF fcb $d,Ja,0 1276 0A 1277 00 1278 20 SrcTxt fee / S» / 1279 53 127A 3A 127B 20 127C 00 fcb 1270 20 OestTxt fee / D: / 127E uu 127F 3A 1280 20 1281 00 fcb 1282 20 BCntTxt fee / *l / 1283 23 1281 3A 1285 20 1286 00 fcb end 284 April 1981 © BYTE Publications Inc KEYS TO PRODUCTIVITY BACK SPACE If you plan, make, use, or "buy computer systems or services, you can't afford to miss the upcoming National Computer Confer- ence, McCormick Place, Chicago, May 4-7 The theme of this year's conference is "Keys to Productivity", how to use computers and computer services to help increase output and control costs. Come see the latest in new equipment and money-saving techniques at over 300 exhibits. Take your pick of over 100 technical sessions and 21 Professional Development Seminars. 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(312)684-3183 J COMPUTEX ^^. \ MICROCOMPUTER SYSTEMS V \ \ 5710 Drexel, Chicago, IL 60637 Text continued from page 268: put from the serial line; it detects frames, parses them, and performs the appropriate action. The state of the receive program is saved whenever calls to GETBYTE are made. (It is conceptually easier to im- agine that a call to GETBYTE results in a wait followed by a return with the next input byte from the line. Actually, a call to GETBYTE results in the storing of the return address in ACIASTATE and the execution of a return from interrupt instruction. The next line input interrupt then causes a branch to the address in ACIASTATE, which reenters the receive routine at the right place to process the next incoming byte.) Incoming bytes are first checked se- quentially for the presence of DLE bytes. If a byte is not a DLE, it is printed on the local terminal. Other- wise, the DLE signals the beginning of a frame, and the STX and opcode bytes are received and checked. An opcode of hexadecimal 30 im- plies that the next 2 bytes are to be stored in ADDRESS, high-order byte first. The checksum is then tested. If it is correct, the XMITACK flag is set to 1; otherwise, the XMITACK is set to — 1. The send module will eventually notice this work request and issue either an ACK or a NAK frame. An opcode of hexadecimal 31 im- plies a data frame. Since the start ad- dress has already been verified in the address frame, data bytes are stored in their proper memory locations as they arrive. When a DLE DLE is detected, only one DLE is stored. If, however, a DLE ETX is detected (denoting an end of frame), the checksum is verified and and XMITACK flag is set accordingly. An opcode of hexadecimal 32 im- plies receipt of an ACK frame, and an opcode of hexadecimal 33 implies receipt of a NAK frame. Both are verified for accuracy by comparing the computed checksum to the re- ceived checksum, and the RECDACK flag is set accordingly. This informs the send module whether the next ad- dress or data frame may or may not be sent. At the end of each frame, control returns to the beginning of the receive program so that the next frame (or stream of keyboard characters) may be properly interpreted. Debugging Debugging is best accomplished if the code can be separated into modules that can be tested in- dependently. As indicated earlier, there are three major modules: the command interpreter, the send routine, and the receive routine. I have found the following order to be the easiest way to debug the program routines: • the transparent mode routine • the receive routine • the command interpreter • the send routine The computer was connected to itself, as described earlier, for testing purposes; this was done by connect- ing the transmit line of the send routine to the receive line of the receive routine. In this way, I was able to confine bugs to only one machine. Proper operation of the transparent mode code is verified by the double echo on the terminal. Each character typed in is echoed on the console from the send routine. The character is then sent on the line, where it is received by the receive routine and again typed on the same console. When two separate computers are connected, of course, only one character is typed on each console. The receive routine can be de- bugged independently by keying in protocol frames on the keyboard and observing what the receiver does with them. Normally, the DLE, STX, and ETX characters are defined with the high-order bit on, which precludes their generation by the keyboard. (This is to ensure that keyboards can- not accidentally send a protocol frame.) During debugging, however, the value of the DLE, STX, and ETX bytes can be changed to keyboard- generated characters, thereby allow- ing frame synthesis through the keyboard for debugging purposes only. The send routine must be disabled during this stage of debugging by changing the BNE INZADOR at hexadecimal location 1045 to BRA XMITLOOP. This ensures that the XMITACK flag from the receive module does not cause an ACK or NAK to be sent, thus clearing the flag. First, an acknowledge frame is 286 April 1981 © BYTE Publications Inc FREES EASY .... that's our new catalog, filled with super buys on computers, peripherals, accessories and supplies. It's free and it makes buying easy for you. Just ask for it! ■Mt APPLE ACCESSORIES Sanyo Monitor 9" B/W $169. NEC Monitor 12" GN 229. LOBO Disk ll/Contoller DOS 3.3 499. LOBO Disk II 399. SCIPERTERM 80 Col. Card <329. Z80 Soft Card 295. H.S. Serial Card 179. COMM Card 179. CLOCK Calendar Card 225. ROM Plus Card/KB Filter 175. HAYES Micromodem 319. SCIPERTalker 249. PARALLEL Printer Card 149. SOFTWARE V1SICALC 119.00 DESKTOP Plan II 169.00 PERS Filing Syst 80.00 ADDRESS Book 40.00 SUPER Text II 125.00 CCA Data Mgmt 85.00 Vi MODEMS CIDS 103 LP, direct $169.00 NOVATION CAT, acoustic 159.00 D-CAT, direct 169.00 LEXICON LX-11, acoustic 147.00 HAYES Micromodem, S100 349.00 SI 00 CORNER Boards Xitan ZPC1 (Z80) $ 129. SMB-2 1/O 199. D-16K Dynamic 129. D-32K Dynamic 199. Mainframes Xitan 8 Slot $ 199. CCS 12 Slot 349. NNC 19 Slot 590. Computers NNC System 80-1MB $3,995. NNC System 80W-8.4.MB 6,995. Z-80 SOFTWARE Cass otto Disk 8K Basic $50. Super Basic $95. $99. Disk Basic $159. ZAPPLE Text Ed. $ 35. $ 69. Z-TelTextEd. $50. Text Output Proc $50. Macro Assembler $50. $69. Z-Bug $89. Micro Z-BGG $69. LINKER $69. Fortran IV $249. ircle 184 on inquiry card. PRINTER SALE DIABLO 630 RO 30 cps letterquaiity, plastic or metal Daisy wheel List $2,71 1 .00 $2,395.00 TYPRINTER 221 Word Processing W/KEYBOARD 20 cps computer printer and typewriter in one. Non ualatile memory up to 16K. Auto error correction. 10. 12 and 15 pitch letter quality characters. Proportional spacing works with most word processing software. List $2,850.00 $2,450.00 ESCON CONVERSION FOR IBM SELECTRIC Complete with micro processor controller and power supply. Standard serial, parallel and IEEE versions available. List $599.00 $539.00 PRINT ELEMENTS NEC Thimbles $16.00 Plastic Daisy Wheels for Qume, Diablo, Starwriter 6.00 Metal Daisy Wheels 56.00 IBM Selectric Elements 17.00 RIBBONS NEC $71.00/Doz. QCIME 54.00/Doz. DIABLO 54.00/Doz. ANADEX 144.00/6 ea. ANACOM/QUANTEX 192.00/Doz TI/DEC/TTY 50.00/Doz. © MAGNETIC MEDIA Premium Quality At Bargain Prices 5V4' Diskettes, all Formats, 1 00 % Certified with hub rings, box of 1 Single sided, single density $22.50 Single sided, double density 24.50 Double sided, double density 32.50 8" DISKETTES, ALL FORMATS 100% CERTIFIED Single sided, single density $26.00 SSSD Error Free 27.00 Single sided, double density 34.50 Double sided, double density 40.00 3M DATA CARTRIDGES, 1/4" Regular $18.15/ea. Regular Error Free 20.65 Mini 15.25 DIGITAL PHILLIPS CASSETTES, 1/4" For Most Systems $3.60 MPI 88 G Matrix High resolution dot-addressable graphics for Apple. Enhanced "correspondence quality" printing. Tractor and Friction feed. Serial and Parallel Input 100 cps Bidirectional printing, 80. 96, and 132 column widths! List $799.00 $599.00 ANADEX DP 9500/9501 200 cps Matrix, high density dot addressable graphics serial and parallel input, up to 2K buffer! List $1,650.00 $1,395.00 TI 820, RO Full ASCII 150 cps Matrix, wide carriage, data processing workhorse. List $1,995 $1,695.00 ANACOM 150 Heavy duty 150 cps Matrix 15" carriage, low cost replacement for TI 820. List $1,350.00 $1,095.00 QCIANTEX 6000 MATRIX Heavy duty 150 cps 15" carriage. List $1,495.00 $1,195.00 NEC - SPINWRITER 55 cps Bidirectional, tetter qualitu 5510 RO List $3,055.00 $2^,595.00 C. ITOH - STARWRITER RO 25 cps Low cost Daisy Wheel List $1,895 $1,695.00 QCIME SPRINT 5/45 RO 45 cps Daisy Wheel, High Quality List $3,137.00 $2,595.00 TO PLACE YOUR ORDER CALL: TELEPHONE TELEX (714) 744-7314 697120 or write to: PAlOMAft Computer Products 910-105 W. San Marcos Blvd., San Marcos, CA 92069 TERMS OF SALE: Cash, check, money order, bankwire transfer, credit card or purchase orders from qualified firms and institutions. Please include telephone number with order and expiration date on credit card orders. California residents add 6% sales tax. Advertised prices are for prepaid orders F.O.B. shipping point. Add 3% for shipping in U.S. Pricing and availability subject to change without notice. ill Circle 185 on inquiry card. You can buy at wholesale prices through a commercial buying firm and save more than buying mail order. The fee is one quarter of what they save you off list — an incentive for them to save you more. Minimum fee of $75. y # f Whse. 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Call for other prices! df The Purchasing Agent 1635 School Street, Suite 101 Moraga, CA 94556 (415) 376-9020 International Telex 470851 keyed in to test the receive routine's response. The RECDACK byte, as a result, should be set to a value of +1. Next, a NAK frame is keyed, which should get the RECDACK byte to — 1. If these received frames do not result in the proper setting of the flags, then either the receive routine is faulty, or the frame was keyed in- correctly. After a proper address frame is typed, the XMITACK flag should be set to 1; otherwise, it should be set to — 1. Also, a proper address frame should put the address types in the 2-byte variable ADDRESS. Finally, frames of varying length and content should be typed in, and memory should be checked to ensure that the data has been properly stored. Of course, the keyboard can- not generate bytes with the high- order bit on, but this should not affect the debugging process. A proper data frame should set the XMITACK flag to 1, while a bad frame should set it to — 1. The command interpreter is de- bugged next by typing a control-F character and noticing that an "S:" is typed on the console. Typing in four hexadecimal characters and a carriage return should result in a "D:" being typed on the console. The command interpreter checks for valid hexa- decimal characters, which in this im- plementation are lowercase "0" thru "9" and "a" thru "f." Either typing in a bad character, or typing more than five characters, results in the ringing of the terminal's bell. After the destination address is keyed, a "#:" should be typed on the console. When the byte count and a carriage return are typed, the user should cause system reset and go to the computer's monitor program (in my case, a Motorola MIKBUG). Locations SRCADDR, DESTADDR, and BYTECNT should contain the proper values of the three parameters just typed in. Also, the XMITFILE flag should be nonzero. If any of the above information is not correct, the command interpreter has errors and must be debugged. The debugging of the send routine is the last and most difficult task. The patch introduced to disable the send routine must be deleted and the original code restored. The command interpreter is then used to set up the addresses and a byte count; a carriage return is struck to initiate the send Prices subject lo change without notice. routine. Normally, the send routine will send out an address frame and wait for the RECVDACK flag to in- dicate proper receipt of the frame. It will then send a data frame and again wait for the RECVDACK flag. Since the transmit line is connected to the receive line during these tests, a more complicated interaction occurs. The interaction is as follows — the sender issues an address frame and the receiver, in turn, sets the XMITACK flag. The sender sees the XMITACK and sends an ACK frame, and the receiver receives the ACK and sets the RECVDACK flag. The sender, noticing the RECVDACK flag, sends a data frame. Errors result in up to three retransmissions before the file transfer is aborted and the computer returns to transparent mode. This sequence of events can be verified by disabling various portions of code and watching the flags change using a debugging routine (there is usually one in the computer's monitor program). Once the software routines have been independently debugged as described above, there should be few problems when a final test is made with two computers linked by a serial line. Final Notes Reliable data transmission between two computers over a noisy channel is a primary concern of communica- tion engineers, who have developed a spectrum of elaborate protocols to ensure that errors are detected and corrected. The simple data link described here is not overly robust. For example, the computer will "hang up" waiting for a valid response when an ACK or a NAK is received in error and discarded. One solution is to in- clude a timeout interrupt that causes the send routine to retransmit its data if an ACK or NAK is not received within a certain period of time. Although the routines shown here were written with simplicity and minimal software in mind, the reader is encouraged to add this feature. The protocol presented here is computer independent and could just as well be implemented in the machine language of any microprocessor. As long as there is agreement on the electrical interface and on the data-transfer protocol, a computer can pass data of any kind to any other computer. ■ 288 April 1981 © BYTE Publications Inc MEMOREX SUPERB QUALITY AT UNBEATABLE PRICES. THAT'S MEMOREX DISCS FROM PACIFIC EXCHANGES For Data Reliability — Memorex Flexible Discs CALL FREE FOR PRICES & INFORMATION (800)235-4137 In California, (805)543-1037 VISA DEALER INQUIRIES INVITED :- «5* W C.O.D.s ACCEPTED Circle 187 on inquiry card. BYTE April 1981 289 Three-Dimensional Computer Graphics, Part 2 Franklin C Crow Department of Computer and Information Service Ohio State University 2036 Neil Ave Mall Columbus OH 43210 Last month, in Part 1, we examined almost every algorithm needed to display three-dimensional line draw- ings that represent solid objects modeled by polygons. I attempted to keep the procedures concise, at the occasional sacrifice of clarity or effi- ciency. Listing 1 contains a complete Pascal program that incorporates the individual graphics procedures presented in Part 1. I have used this program with the Heath/Zenith H-19 video terminal (which has limited semigraphics) and the UCSD (Univer- sity of California, San Diego) Pascal system. I have also used it (very satisfactorily) with a 500-line raster graphics display and a Pascal inter- preter running under the UNIX operating system on a DEC (Digital Equipment Corporation) VAX 11/780 computer. The program includes facilities for all of the basic functions necessary for three-dimensional representation : • acquisition of machine-readable data • transformation to the proper perspective • scaling • elimination of hidden lines and faces In presenting this program, I have assumed that your display system can draw lines, as most systems that are capable of full graphics provide ap- propriate software. However, scan- conversion software is included to support the Heath /Zenith H-19 video terminal, and the routines Moveto and Drawto can be easily modified for any other raster display. area of three-dimensional graphics As designers continue to simplify software will be the next to receive the use of personal computers, the significant attention. ■ Listing 1: Complete UCSD Pascal three-dimensional graphics program that incorporates the ideas and procedures put forth in Part 1 (see March 1981 BYTE, page 54). Program Hi d e L i n e s const DotsA«ross = 79! IJotsDown = 47; MaxPts = 200; MaxPois ■= 200; MjxVt;: = 800; MaxSides - S; (* main mum sides on a polygon *) ( * main mum si des 0. . MaxVtx; t y p e c u ri t e Point, = record X, Y, I : real end; Vertex = MaxPts; Polygon • record NumVt:-; : Vertex; Start UnePoly = array Ci. . MaxSi des] of Point, Polygons ■ array C 1. . MaxPol S3 of Polygon; Vertices ; array [J. . MaxVtxJ of vertex; OutPolys : array Ci. . MaxPol s] of Polygon; OutVtces ■ array CI. . MaxVtx] of Point; EyeSpace Matrix; Window : UnePoly; *) ± y e p o i n t a n d LyePt. Cntr I nt : Poi nti (* ScreenSeal e, ScreenCtr : Point; SereenX, ScreenV : real; Screen ■ packed array CO. . DetsAcri NumPols, NumWtees, NumPts, Wi ndowSiz< IM u m LJ i s p 1 a y » N u m V t ;■: u I ■ counter; CiiidChar char; h i 1 eName : ftlri ng; lion- : boolean; * ++-M-+-+++4-+++++ uetPlanes ++++++++++++++++++-» irocedura GetPUnesI var Poly ; OnePoly; NuillPts >ar liLstl : counter; TinpPoly ■ OnePoly; ( -Jf o i" i g i r; a 1 p ol y g o n s I * original v e r t i c e 5 (# displayed polygons ») (* displayed points # i (■* eye space transform #) <# display window #) • nter 5 f i n t e r c is, 0. . DotsDownl of boolean; I c. u n t e r ; 4-H- + + + H c 1 .1 n 1 1 h e g 1 11 ' 3 c om p u t e p 1 a n e e q u a t i ; Lsti : = NumPts; for I: ~i to NumPts do begin with Poly CI] do b e g i n "ImpPolyCl J. X : = V ■» PolyCLstll. 2 - 7 » Pol I'mpPolyCn. Y ; = Z * Pol y [Lsti II. X - X # Pol ImpPoiyi: I 3. 7 := X * PolylLslll. Y - Y * Pol end; Lstl : = 1, end; (* for 1 oop * ) for I :-■■.! to NumPts do £* copy back to input with TinpPolyCI J do begin PolyCIl . X: -X; Pol y L I ]. Y: -Y; PolyLi end; (# GetPlanes #) 3 e f f 1 c 1 e n t s y L l yCL. p 1 y g o n e d c ,tll. Y; ; 1 1 j '.'., ; 1 1 1 x , ;edure I ; c reenScai i Listing 1 continued on page 292 290 April 1981 © BYTE Publications lnc Automated Equipment Incorporated "1S430 Ward, Fountain Valley, CA 3270S Call Toll-Free for latest low prices! 1-800-854-7635 Outside CA 714-963-1414 Inside CA 1-800-854-7635 Outside Cont. USA Prices change daily to meet competition. TERMINALS TELEVIDEO 912 B S665 TELEVIDEO 912 C 665 TELEVIDEO 920 B 945 TELEVIDEO 920 C 715 SOROC IQ-120 675 ZENITH A- 19 735 HAZELTINE 1500 850 TELEVIDEO 950 CALL NORTHSTAR HRZ-1D-32K $1975 HRZ-2D-32K 2270 HRZ-1Q-32K 2240 HRZ-2Q-32K 2650 ADDITIONAL 16K RAM 365 ADDITIONAL 32K RAM 475 HARD DISK SYSTEM 3900 SPECIAL MEMORY CONFIGURATIONS AVAILABLE. INCLUDING SYSTEMS GROUP. VIP's customarily need top quality and service within stringent budgetary limits, naturally, they call A.E.I. Item: A.E.I, tests virtually every" item sold, before shipping. Item: A.E.I, initializes every piece of soft- ware, and makes a copy. If you have a problem. A.E.I, can check to locate the problem by using the in-house duplicate, saving you time. Item: A.E.I, has in-house expetise on every item offered Item: A.E.I, prices are competitive with the lowest, no-service, no in-house exper- 40% OF ALL A.E.I. SALES ARE TO PUBLIC AND SEMI-PUBLIC INSTITU- TIONS. A partial list*" of A.E.I, customers who purchased during the last quarter of 1980 includes: University of Nebraska, Univer- PRINTERS NEC 5510 (TRACT.. RIB., THIM) . . . $2540 NEC 5515 (TRACT.. RIB.. THIM) .... 2600 NEC 5520 (TRACT.. RIB.. THIM) .... 2900 NEC 5530 (TRACT. RIB.. THIM) 2540 MALIBU 1800 TI-810 1495 TI-820 1625 EPSON MX 80 CALL EPSON MX 70 CALL ANADEX DP-9500/9501 CALL VIP's Call A.E.I. sity of Virginia. U.S. Dept. of Interior, Uni- versity of Kentucky. University of Cali- fornia. Massachusetts Institute of Tech- nology, U.S. Air Force, Naval Air Develop- ment Center, Brown University, University of Oregon. University of Utah. Ohio State University, University of Southern Cali- fornia. California State Dept. of Water Resources. University of Michigan, and Princeton University. In the private sector, an equal number of major national organizations purchased during the same period. You can call A.E.I, too! 'With our normal fast shipping, we have lime to test. expedited shipment may preclude testing "AE.I. does not wish to imply thai any or these fine organizations endorse A El . merely that A El is proud to have them as customers S.S.M. KIT ASM CB2 Z80 CPU S200 S265 VB1C VIDEO 140 190 VB2 VIDEO 155 210 VB3 VIDEO 375 440 I04 INTERFACE 165 225 SB1 SYNTHESIZER 195 270 MEASUREMENT SYSTEMS MEMORY DM3200 32K 4MHZ 480 DM6400 64K 4MHZ 595 DMB320032K4MHZ BANK SELECT .. 630 DMB6400 64K4MHZ BANK SELECT .. 745 DYNABYTE SYSTEMS ALSO AVAILABLE— CALL FOR THE EXCITING NEWS ABOUT NEW COMPETITIVE PRICING! WE WILL TRY TO BEAT ANY ADVERTISED PRICE. TERMS: All prices listed are cash discounted and subject to change. COD's are 2% additional. Universities and well-rated firms Net-10. SHIPPING: ADDITIONAL IN ALL CASES. TECHNICAL ASSISTANCE: WE TRY TO HELP INTERFACE AND TROUBLESHOOT— CALL (714) 963-1414. Open Monday-Friday, 8:00 a.m. -5:00 p.m. Dealer Inquiries Invited. MISCELLANEOUS NEC THIMBLES $16 NEC RIBBONS 7 RS2332 CABLE 5" 20 RS 232 CABLE 10" 25 LEDEX MONITOR 145 NOVATION CAT 145 MORROW DECISION 1 BASIC $1550 DISCUS-1 2 DRIVE 1550 DISCUS 2D 1 DRIVE 935 DISCUS 2D 2 DRIVE 1550 DISCUS 2+2 1 DRIVE 1250 DISCUS 2+2 2 DRIVE 2190 DISC JOCKEY 2D 350 DISCUS M26 HARD DISC 3925 ADDITIONAL HARD DISC 3685 DISCUS M10 2990 SOFTWARE WORDSTAR $320 MAILMERGE 100 DATASTAR 250 N.S. PASCAL 295 MAGIC WAND 290 C BASIC 100 ADDITIONAL SOFTWARE DISCOUNTS WITH SYSTEM PURCHASE GRAHAM-DORIAN JOB COSTING $700 INVENTORY 475 CASH REG 475 APARTMENT 475 MEDICAL 700 DISCS— BOX OF 10 VERBATUM 5'/.. 1 SIDE .... $27 VERBATUM 5V, 2 SIDE 45 VERBATUM 8 1 SIDE 35 VERBATUM 8 2 SIDE 55 OTHERS CALL PLASTIC STORAGE BOXES 3 OUR SYSTEMS WORK! All systems normally tested and configured in our repair facility before delivery. Service contracts available. Prompt repairs and warranties. rMMaa^HMMBi^BMBMaBri Circle 188 on inquiry card. ■■■MMaMHHBHMMaMM Circle 189 on inquiry card. BASF "FLEXYDISK"... Superior Quality data storage medium. Certified and guaranteed 100'';. error free. SINGLE SIDED-SINGLE DENSITY 5V4" or 8" Diskettes 10/$24 5V4" or 8" Vinyl Storage Pages 10/ $5 MAXELL- DISKETTES The best quality diskette money can buy. Approved by Shugart and IBM. Sold onlv in boxes of 10 5", 1 side $3.30 8", 1-side $4.25 5", 2-side $3.90 8", 2-side $5.60 ALL MAXELL DISKETTES ARE DOUBLE DENSITY LIBRARY CASE... 3-ring binder album. Protects your valuable programs on disks Fully enclosed and protected on all sides. Similar to Kas-sette storage box Library 3-Ring Binder $6.50 5%" Mini Kas - sette/10 $2.49 8" Kas-sette/10 $2.99 DISKETTE DRIVE HEAD CLEANING KITS Prevent head crashes and insure efficient, error- free operation. 5M" or 8" $19.50 SFD CASSETTES C-10 Cassettes 10/$7 (All cassettes include box & labels) Get 8 cassettes, C-10 sonic and Cassette/8 library album for only $8.00 (As illustrated) HARDHOLE Reinforcing ring of tough mylar protects disk from damage 8" Applicator $4 5V*" 50/8" Hardholes $8 Applicator $3 5W' Hardholes $6 VISA • MASTERCHARGE • MONEY ORDERS CERTIFIED CHECK • FOR PERSONAL CHECKS ALLOW TWO WEEKS • C.O.D. REQUIRES A 10% DEPOSIT • CAL. RES. ADD 6% SALES TAX MIN $2 SHIPPING & HANDLING • MINIMUM ORDER $10 • SATISFACTION GUARANTEED OR FULL REFUND Write for our free catalog ABM PRODUCTS 631 B ST. SAN DIEGO, CA 92101 (714)235-6602 Listing 1 continued: MaxX, MinX, MaxY, MinY : real; begi MaxX f o r ...i 1 1 h b l MaxX i f M than else S e r e S c r e end; n : =0. 0* [:=L t. Window eg in f X/2 f X/2 f Y/Z f Y/Z ndi Ma axY > S c r e Scree nScal nSeai <* MinX: =0. Oi MaxY:=0. Oi MinY:=0. Ol (» window must, include Z-axis W i n d owS i z e d o £13 do > MaxX then ttaxX :- X/?.; ■C MinX then MinX : = X/Zi > MaxY then MaxY : ■ Y/Zi < MinY then MinY : » Y/Z; X - MinX; MaxY :» MaxY - MinY; (0. 73 * MaxX) (* standard display is 3 units high by 4 uidr- *) nScale. Z : = (MaxY * 4 / 3 ) nScal e. Z : = MaxXi e. X : - DotsAcross / ScreenSeal e. Zi e. Y : = ( DotsDown * 4 / 3 ) / ScreenScale. Z; a tScr e e nS cal e # ) begi n Hone : = false; NumPol s : = 1 Numjjispj ay : - Oi NumVtees ;= Oi NumPts : = ; 0i mi th EyePt do begi n X: w.ith Cntrlnt do t Jin X: -0. Oi z = 16 Oi end z = 16 Oi end ? =16 Oi end z ■ 1 6 Oi end Y: =DotsDown/2i Wi ndowSj ::e : = 4; with Window!!] do begin X:=-4. Oi Y: —3. Ol with WindowE21 do begin X:=-4. 0; Y: = 3.0; with WindowC3J do begin X: = 4.0; Y: = 3.0; with WindowC43 do begin X:= 4.0; Y:=-3. 0; LietSc reenS'cal e; GetPlanest window* WindowSize ); with ScreenCtr do begin X: =DotsAcross/2i e n d i ( * Initialize * ) (# ++++++ start +++++++++++++++++++ *) p r o c e d u r e S t art; var I, J : counter; begin (* clear screen *) tor 1 : -- to DotsAcross do for J := to DotsDown do Screen! I, J 1 end; (# start «•) var I, J : counter; begin write(chr(27>, -F ' ); (* put terminal into graphics mode ») wri Te( chr (27) , ■' p*' ) ; (* put terminal into reverie, video ■& i wri te(ehr(27), 'W >i <» no wraparound at end of line *) ...I : = DotsDown; while J > do b eg i n for I : o to DotsAcross do if Screen!, I, ..I] and ScreenE I , d-i ] then write('q-) else if ScreenLI, .J-n then wr 1 t e ( ' 1 ' ) else if SereenEI, J] then writet -o-> else write! " ' )| if J > 1 then J : - J - 2 (# count down by two--, #) else J : - 01 if J > then writelni (* CR/LF unless last line ») end; readln, (* await CCR> before continuing (preserves screen) write( chr(27), -Q' )i (# exit graphics mode *) wri tefchrC?/ >,■■'.:;■' )i C* exit reverse video ») endi (* Finish #) (# +++++++++++++++ Mo veto ++++++++++++++++++++ *) procedure Movatof X.Y : real )i begi n ScreenX :- Xi ScreenY :- Y; endi (* Moveto *) (* ++++++++++++++++++ rirawto +++•+-++++++++++++++ #) procedure Drawtol X,Y : real >; var I : counter) Dxi Dy, Length- StepX, StepY, Xpos, Ypos : reali begin (* Drawto *) Dx := X - ScreenX; Dy ; = Y - ScreenY; > abs(fly) then Length : = abstDx! else Length : = abs(Dy); 1.0; (« catch zero-length lines #) if Length 1. then Length Listing 1 continued on page 294 292 April 1981 © BYTE Publications Inc Are important letters and reports leaving your office with spelling errors? ELLGUARD can proofread 10,000 words in one minute. SPELLGUARD is a revolutionary new computer program that finds spelling mistakes and typographical errors in documents prepared with CP/M 1 or CDOS 5 compatible word processors and text editors. In less than one minute, SPELLGUARD proofreads 20 pages of text (10,000 words) and identifies all misspelled or mis-typed words based on its 20,000-word dictionary. After proofreading, SPELLGUARD first provides an alphabetized list of the words identified as potential errors. The operator judges each word as correct or incorrect. Correct words may be added to the dictionary. SPELLGUARD automatically marks incor- rect words in the text with a special character. The operator can then use ■the word processor to easily find and correct them in the document. SPELLGUARD is Easy to Use • proofreading capabilities are mastered in a few minutes. • comprehensive user's manual contains step-by-step examples of all SPELLGUARD features. SPELLGUARD is Powerful . text files to 85 pages (CP/M 1.4), and 2,800 pages (CP/M 2.0). includes a 20,000-word, expandable dictionary. • contains powerful commands to construct customized dictionaries for special areas, e.g., medicine, real estate, law, insurance, engineering. SPELLGUARD is Reliable • thoroughly tested in actual use with free one-year maintenance service. • 30-day money-back limited warranty. • includes computer program for software updates and maintenance. Minimum System Requirements: 8080/85, Z80 CPU wilh 32K memory: CP/M 1 1.4 (dictionaries to 2.S6K bytes). CP/M 1 2.0 or laier (dictionaries to 4 MB), or CDOS; word processor or text editor compatible wilh SPELLGUARD (currently several excellent new CP/M word processors, and WordStar. WordMaslcr. Magic Wand'. Electric Pencil 4 , and ED). Trademarks: 'Digital Research (registered). -MicroPro Int'l Corp.. :< Small Business Applications, 'Michael Shrayer Software, "'Cromemco. "Time estimates based on 4Mhz 8085 with 48K memory. CP/M 2.1 double density 8" floppy drive, 10,000-word text file. The price of SPELLGUARD includes rapid turnaround and delivery by UPS or airmail. Sales will be made only if the purchasers' word processor is compatible with SPELLGUARD. Software license agreement is required. □ Send me a free, detailed description and latest diskette format availability. □ Send me SPELLGUARD at $295.00. (Manual and diskette(s). Formats: 8" CP/M single density Shugart compat- ible, and 554" Northstar double.) □ Send me copies of the SPELLGUARD manual at $20.00 each. (Airmail, credited toward purchase.) □ Send COD (add $10.00 handling). California residents add 6% tax. Add $10.00 for foreign shipment. Check enclosed for $ . (Certified check, COD. and money order shipped immediately.) ORGANIZATION WORD PROCESSOR COMPUTER SYSTEM ISA INNOVATIVE SOFTWARE APPLICATIONS Box 2797. Menlo Park, California 94025 415-326-0805 DISK SIZE DISK FORMAT I Checks payable to ISA j 1 | Box 2 797, Menlo Park, CA 94025. I (Dealer inquiries invited.) STATE-OF-THE-ART SOFTWARE Circle 190 on inquiry card. BYTE April 1981 293 SOFTWARE DEUELOPIflEIT? TOOLS FOR IRDUSTRV CP/M CROSS-ASSEMBLERS Fast, comprehensive cross-assemblers to run under CP/M.* Extensive pseudo- ops include full listing control, nested conditonals, mnemonic synonyms, and inclusion of external source files. Gen- erate object file, assembly listing, and symbol table from source code for nine popular microprocessor families. XASM05 6805 XASM09 6809 XASM18 1802 XASM48 8048 XASM51 8051 XASM65 6502 XASM68 6800/6801 XASMF8 F8/3870 XASM400 COPS400 Assemblers .... $200.00 each Manual only. . . . $25.00 8048 DEVELOPMENT PACKAGE Now you can use the 8048 family of single-chip microcomputers without buying expensive equipment. Develop 8048 software with the XASM48 cross- assembler. 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Listing 1 continued: StepX ■ = Dm i Length; Xpos : ~ ScreenX; StepY : = Dy / Length; Ypos : = ScreenY; for I : = to trunc (Length! do begin S c r c >"■■ n C r o u n d < X p o s ) . r o u n d ( Y p o s ) 1 ■. = t r u a ; X r . s :- Xpos + StepXj Ypos := Ypos + StepY; end; ScreenX : = X; ScreenY ; = Yi end; t* Dr-Aiut *) (■it +++++++++++++++++ ReaoUbjeet +;■+++++++++++++++++++++ #) procedure ReadQbjectl FileName : string >; (* read in object from disk vsr PtsObj. PolsDb j, PtsPol , 1 , J : counter; Xposi Ypos, If s ■ real; D-bjf- i le : til<,- of ehsri begin ...ir i If i -I' vititm for ■' , F i 1 eNanle, ' X Y I : ' ) , r eadl r, ( X pos, Ypos, ?. pos > ; reseUObjFiie, F ileNamei ; ( * open object file *) r e a d 1 n l b j F 1 1 e , p I s b j , P o 1 sO b j ) i for I =1 to PtsObj do with Poi nts[. L+NumPts] do begin r e,-:d] mObjhj J e, ,J, X, Y. /'. ) , X ;■=> X + Xpos, Y : = Y + Ypos; 7. :.= I + Z p o s i end; for .1 : =1 to PolsOb j do begin l eadlUbjFi le, PtsPol ); < -t for J ; = l to PtsPol do : d p o 1 y g o n v e r t e : : p 1 I beg i n read' Ob.iF i i e, Ver 1 1 .:: es 1 .J+NumV t c es] ), Ver fi eesPJ+NuiriVtces .1 := Vert i cesPJ+NumV tees] + NumPt; e 1 1 j ; eaglmfU, jf i 1 ei, (* reed past end of line *) oi fh Polygons! I+NumPoi s] do begin'" Start : = NurnVtces; N 1. 1 in VI :■: : = Ptsf-'ol, e n a ; NurnVtces :- NurnVtces + PtsPol; end; Nun.Pts := NumPts + PtsObj; NumPols : = NumPols + Polsubj, end; (* Readubjeet #) (■a- +++++++++++++++++++ Mak ePi c t ure +++++++++++++++++++++++•+-++ #) procedure MakeF'i c t ure; £« transform and clip, then display poiyg-: v a r 1 , ,J , N umC 1 p : c o u n t e r ; TmpPoly : OneP oly; (■tt- +++++++++++++ DotF'rod +++++++++++++++++ +++ it) function OotProdC Ptl,Pt2 : Point ) ; real; begi n DotProd : » Pti. X » Pt2. X + Ptl. Y # Pt.2. Y + Ptl Z • Pt2. Z ; end; (* DotF'rod #> (# +++++++++++++++++++-+- I dent +++++++++++++++++++++++#) p r o c e d ure I d e n t ( v a r M t x : Matru; ); (» initialize ma tri x » ) v a r I , J : c o u n t e r ; b e q i n for I; =1 to 4 do for ,J: --=L to 4 do if 1 - J then MtxCI.J] : = 1.0 else Mt>.[I,.Jl : =•■ 0.0; end; (# I dent *) (*, +1- + ++++ + + + + + + ++++++++ flfttri aMuI t H-H-+H-+H- + + +++ + + + + + it) procedure Matri xMul t ( Mtl,Mt2 : Matrix; var Result : Matrix ); va r 1 , .J, K counter; begin for I: =1 to 4 do for U:=l to 4 do begin H65i.ll TCI, .J] : = 0. 0, for K: -=1 to 4 do Result!],. Jl := Resul t [ I , J 1 + M t i UK, J]*I1 t.2L 1 , Kl , end; end; (* MatrixMult *) < -h- ++++++h--i-+++h-+++++-i- Transform +-n-++++++++++H-f+++-i-++-<-++++4-i- #) procedure Transform; Pt : Point; Mtx : Matrix; var NewPt . point begi n NewPt. X := Pt. XitMtxEJ. , 11 + Pt. Y#M 1 xt 1 , 2] + Pt. X*MfxL.i NewPt. Y := Pt. XitMtxf.2, 1J + Pt. Y*M t xC2, 21 + Pt. Z*Mt;:C- NewPt. 7 .= Pt. X#Mt;:C3, 1] + pt. Y#MtxC3. 23 + Pt. Z*MtxC5 end; (if Trans for in *) J + M t >■ [ i. , 4 :l ; 1 + MtxC ', 4 l, J + Mtx [3, 43, Listing 1 continued on page 296 294 April 1981 © BYTE Publications Ire Computer experts (the pros) usually have big computer experience. That's why when they shop system software for Z80 micros, they look for the big system features they're used to. And that's why they like Multi-User OASIS. You will too. DATA INTEGRITY: FILE & AUTOMATIC RECORD LOCKING The biggest challenge for any multi-user system is co-ordinating requests from several users to change the same record at the same time. Without proper co-ordination, the confusion and problems of inaccurate or even destroyed data can be staggering. Our File and Automatic Record Locking features solve these problems. For example: normally all users can view a particular record at the same time. But, if that record is being updated by one user, automatic record locking will deny all other users access to the record until the up-date is completed. So records are always accurate, up-to-date and integrity is assured. Pros demand file & automatic record locking. OASIS has it. SYSTEM SECURITY: LOGON, PASSWORD & USER ACCOUNTING Controlling who gets on your system and what they do once they're on it is the essence of system security. *1 [I I (THEN COMPARE.) Without this control, unauthorized users could access your programs and data and do what they like. A frightening prospect isn't it? And multi-users can multiply the problem. But with the Logon, Password and Privilege Level features of Multi-User OASIS, a system manager can specify for each user which programs and files may be accessed — and for what purpose. Security is further enhanced by User Accounting — a feature that lets you keep a history of which user has been logged on, when and for how long. Pros insist on these security features. OASIS has them. EFFICIENCY: RE-ENTRANT BASIC A multi-user system is often not even practical on computers limited to 64K memory. OASIS Re-entrant BASIC makes it practical. How? Because all users use a single run-time BASIC module, to execute their compiled programs, less memory is needed. Even if you have more than 64K, your pay-off is cost saving and more efficient use of all the memory you have available — because it services more users. Sound like a pro feature? It is. And OASIS has it. AND LOTS MORE... Multi-UserOASIS supports as many as 1 6 terminals and can run in as little as 56K memory. Or, with bank switching, as much as 784K. Multi-Tasking lets each user run more than one job at the same time. And there's our BASIC- a compiler, interpreter and debuggerall in one. An OASIS exclusive. Still more: Editor; Hard & Floppy Disk Support; Keyed (ISAM), Direct & Sequential Files; Mail-Box; Scheduler; Spooler; all from OASIS. Our documentation is recognized as some of the best, most extensive, in the industry. And, of course, there's plenty of application software. Put it all together and it's easy to see why the real pros like OASIS. Join them. Send your order today. OASIS IS AVAILABLE FOR SYSTEMS: Altos: Compucorp: Cromemco Delia Producls: Digital Group: Digital Microsystems: Dynabyte: Godbout. IBC. Index: Intersyslems: North Star: Onyx: SD Systems: TRS 80 Mod II Vector Graphic. Vonmex CONTROLLERS: Bell Controls; Cameo Corvus: Konan: Micromation: Micropolis: Tarbell: Teletek: Thinkertoys: X Comp Write for complete. free Application Software D rectory PLEASE SEND ME: Price with Manual Product Manual Only OPEHATING SYSTEM (Includes: EXEC Language File Management: User Account ng; Device Drivers; Print Spooler; General Text Editor, etc ) SINGLE-USER St 50 S17.50 MULTI-USER 350 17.50 BASIC COMPILER/ INTERPRETER/DEBUGGER too 15.00 RE-ENTRANT BASIC COMPILER/INTERPRETER/ DEBUGGER 150 15.00 DEVELOPMENT PACKAGE (Macro Assembler: Linkage Editor; Debugger} 150 25.00 TEXT EDITOR & SCRIPT PROCESSOR 150 1 5 00 DIAGNOSTIC S CONVERSION UTILITIES (Memory Test. Assembly Language: Converters: File Recovery: Disk Test File Copy Irom other OS; etc ) 100 15.00 COMMUNICATIONS PACKAGE (Terminal Emulator File Send & Receive) PACKAGE PRICE (All ot Above) SINGLE-USER 500 60.00 MULTI-USER 850 60.00 FILE SORT 100 15.00 COBOL- ANSI 74 750 35.00 Order OASIS from: Phase One Systems, Inc. 7700 Edgewater Drive, Suite 830 Oakland, CA 94621 Telephone (415) 562-8085 TWX 910-366-7139 NAME_ STREET (NO BOX rr) CITY STATE AMOUNTS ZIP (Attach system description; add S3 for shipping; California residents add sales tax) ■ □ Check enclosed □ VISA □ UPS COD. □ Mastercharge Card Number Expiration Date Signature MAKES MICROS RUN LIKE MINIS Circle 191 on inquiry card. BYTE April 1981 295 Circle 192 on inquiry card. MBC Systems, Inc.^ (203) 342-2747 NORTH STAR HORIZON: HRZ-2-32K-D-Factory ASM$2275 HRZ-2-32K-Q-Factory ASM$2675 64K DD or Q Also Available HDS-18-F $4449 Northword DQ $ 359 INFO-Manager $ 365 Mail Manager $ 269 General Leger $ 775 ACC. REC. OR ACC. PAY..$ 445 Word Star $ 350 Medical-Dental SYS $2500 ■siimmm am COMMODORE (PET) : 2001-32K-BorN Keyboard $1090 16K Also in Stock. ...$859!!! 8032 (80 Column Screen) $1599 2040 Dual Floppy Drive $1090 8050 Dual Floppy (1MEG)$1599 2022 Tractor Printer. ..$ 749 Word PRO IV $ 290 VISICALC $ 195 APPLE II PLUS Call For Price! ATARI 800 $ 849 TI 99/4 Console&Monitor. . $990 INTERTEC SUPERBRAIN: 32K RAM $2595 64K RAM $2695 PRINTERS Letter Quality: NEC 5510 or 5530 NEC 5520 KSR DIABLO 630 C. ITOH Dot Matrix: CENTRONICS 73 0. . 737-1 799.. EPSON MX-80 PAPER TIGER 460G BASE II MST , $2550 ,$2950 ,$2390 ,$1690 , $ 599 , $ 799 ,$ 999 .$ 599 , $1250 ,$ 649 DISPLAY TERMINALS HAZELTINE 1420 $ 949 " " 1500 $ 999 INTERTUBE III $ 775 TELEVIDEO 920C $ 849 Since 1977 complete sales and service. Most items in stock, prices are subject to change. Visa and Master Charge welcome Most items shipped by UPS. MBC Systems, Inc. Multi Business Computer Systems, Inc. 2 8 MARLBOROUGH STREET PORTLAND, CONN. 06480 (203)342-2747 TWX 710-428-6345 M-F 9-6 SAT. 9:30-3:00 Listing 1 continued: (ft +h--i-+++++++++++++ p r o c e d u re Get-Eye S p a var Mtx : Matrix* C1,C2 : PotntJ hi y p o t ertus a, C o s A i S i nA GetEyeSpace +++++++++++■+•+++++++++++++++ ft) < EyePt. Cntrlnt : Point >i real; (ft lead eyepoint translation ft) beyin lderit(EyeSpace>i with EyePt. do begin EyeSpaceCl, 43: =-Xl EyeSpaceC.2, 41 : = -Y: EyaSpaceC3. 4] : = -Zi transform ( Cntrlnt, EyeSpace, CI ); (ft translate ctr. of interest. ft) 1 derit(Mtx> l (» load rotation about Z-axis »> with CI do Hypotenuse := sqrt.( X»X + Y*Y )i if Hypotenuse > 0.0 then begi n CosA := Ci. Y / Hypotenuse) SinA := Ci. X / Hypotenuse! MtKLl.i: := CosA; Mt!-:C2, 11 := SinA; Mtx[.i,2] :=-— SinA; MtxC2, 23 : = CosA; MatrixMult< EyeSpace, Mtx, EyeSpace ); endi Transform! Cn trl nt, EyeSpace, C2 ); (ft rotate ctr. of interest ») IdenUrHx); (« load rotation about X-axis ft) with C2 do Hypotenuse := sqrt( Y»Y + 2*7. ); if Hypotenuse > 0.0 then b e ci i n / Hypotenuse; CosA : -■ C2. Y / Hypotenuse; SinA := -C2. Mtx[2,2j := CosA; MtxI3, 2] :■ SinA; MtxC2,33 :=-SinAl r1txC3, 33 : = CosA; MatrixMult< EyeSpace, Mix, EyeSpace ); end; Ident(Mtx); (ft load switch between Y and Z axes *) MtxC2,2] ;= 0.0; Mt::C3, 3J r= O.O; Htxf.2' 31 :« i.O; MtxE3i23 := i.O; Matri xMul t ( EyeSpace, Mtx, EyeSpace >; end, C* GetEyeSpace ft) (ft ++++++++++++++++++ MakeDi spleyabla +++++++++++++++++++++ ft) procedure MakeDi spl ayar.l e ( var Pt : Point ); (ft take to sere b egi n Pt. X := ScreenScal e. X ft Pt, X / Pt. Z + ScreenC tr. X; Pt Y := ScreenScale. V » Pt. Y / Pt. Z + ScreenCtr. Yi end; (ft MakaDisplayeb] t ft) space ») «-++++++++++++ PacesEye 5Eye( Poly : OnePoly ) b o o 1 £ f + + + + + -H + + + 4 var TmpPt Point) T m p P o I y : O n e P o J. y ; begi wi tr Tm pp TmpP TmpP TmpP TmpP TmpP GetP i f D olyL gi n yCl'J yti: yen yL21 y[2I yI2I nes( Prod en F se F 'J do TmpPt. X: =X; TmpPt. Y: ^Y; TmpPt. X : = PolyClI. X - Poiyr.2:. X Y : - PolyCil Y - Polyt2I. Y Z : = PolyCi:. Z - PolyL2J. Z X : = PolyLSl. X - Polyl2I. X Y := Poly[3J. Y - Po.lyC2], Y Z : = PolyLS]. Z - Polyt?!. 7; TmpP'ol y, 2 ) ; TmpPt, TmpPolytl 1 > O 0.0 acesEye : = f al se . cestye : « true; FacesEye ft) (ft ++++++++++-*-++-»-++■+•+++++ CLipln +++++++++++++++++++++++++++++ ft) procedure Clipln(var Poly : OnePoly; var NumPts : counter), var I, ,J, Lst-J, TmpPts : counter; D1.D2, A : real; TmpF'oly ; OnePoly) begi ■I" o r (ft for each window edge ») 1: =1 to WindowSi za do if NumPts > O then b eg i n Oi :=» DotProdt Pol yCNumPts 3 , Wi ndowL I 1 )i Lst.J : = NumPts; ImpPts : = 0; for ,J:=i to NumPts do (ft for each polygon edge ft) begin if Dl > 0.0 then (ft is leading vertex inside? ») begi n TmpPts : = TmpPts + .1; with TmpPolyC TrnpFtsJ do begin (ft copy leading vertex ft) X: =PolyCLst.JJ. X; Y: ^PolyCLst-Jj. Y; I : =Pol vl Ls t ,J3. Z: end; Listing 1 continued on page 298 296 April 1981 © BYTE Publications Inc PMC-80 Expanded Use all standard peripherals and existing software When you buy PMC-80 you get hard- ware and software compatibility with the most popular microcomputer sys- tem in the world — that means thou- sands of disk and cassette based programs and all kinds of peripherals are instantly available! PMC-80 has configurations that give the computer enthusiast a way to grow from a STARTER system in affordable increments. Begin at a low $675 for the basic 16K level II system and grow to the complete 48K memory system pic- tured above with two floppy disks for less than $3000. FASTLOAD option inputs short pro- grams as fast as "disk" from ordinary, standard format cassettes. Fast, reli- able and economical! PMC-80 COMMUNICATOR option pro- vides interface to modems and parallel port printers. Take your pick of periph- erals for communication with elec- tronic bulletin boards and low cost timeshare services via phone lines from your home or business. PMC-80 EXPANDER option provides the most powerful configuration with a total of 48K memory, provision for 4 mini-floppies, printer interface, RS- 232C communications interface, plus a slot for the popular S-100 boards. Sold through computer stores. Personal Micro Computers, Inc. 475 Ellis Street, Mountain View, CA 94043 (415) 962-0220 Circle 193 on inquiry card. BYTE April 1981 297 Circle 194 on inquiry card. A MICROPROCESSOR TRAINING SYSTEM FOR: EDUCATION INDUSTRY AND MORE! THE Omnibyte Trainer! MC6800/6809 BASED • On Board RAM/ROM • Hex Key Pad & Function Keys • 8 Character Display • Serial/Parallel Interface • KC Standard Cassette Interface • TBUG . Monitor • Comprehensive Teaching Documentation AND MUCH MORE... THE OMNIBYTE TRAINER IS DESIGNED TO LEAD YOU FROM BASICS TO A FULL UNDERSTANDING OF MICROPROCESSORS! Expands into a full development system; or stand alone in a variety of applications (312)231-6880 jjjjjj) 245 W. ROOSEVELT RD. WEST CHICAGO, IL 60185 Omnibyte Corporation 298 April 1981 © BYTE Publications Inc Listing 1 continued: e rnJ ; <» if leading vertex inside *) D2 := DotProd< PolyCJH, Window! I 1 >j if Dl * D2 C 0.0 then t* doe;, edge straddle win b eg i n A : = D i / < D 1 - D2 ) ; TmpPts : = rmpPts + 1; uji i.h TmpPolyC TmpPts: do begin X :- A * PulyLJ]. X + « . 1. - A) * PdlylL-.t. Y ; .= A * l-'oly[.J], Y + (1. - A) * PolyCLst / i m A * PolyL.Jl. Z + (1. - A) # PolyCLst end; endi Lst.J : » Ji Dl : = D2, end; (» NumPts loop *) for J:=J to TmpPts do <* copy polygon back to input. with TmpPolyC J a do begin Pol yl Jl. X : =Xi PolyCJ], Y: =Yi PolyCJl. Z: NumPts ! » rmpPtaj e n dl ( * W i n d owS i z e 1 o .:. p * ) ( * C 1 i p I n * ) n. Yi M. Z; = Z; endi h++++++++++++++++++++ In: :adure JnsertSortl Poly : 1 1 J i k c o u n t e r ; AvDepth : real: ertSort +++++++++++++++++++++++++++ #) OnePolv i NumPts : counter ); begin (* binary insertion sort, on average depth *) AvDepth : = 0. Oi for I: =1 to NumPts do w i t h P o 1 y L 1 .1 d o < * a t o re and find average d e p t h * ) begin t.iutVtcesCNumVtxOut+1+1]. X :- X; QutVtcesCNumVtxOut+I+13. Y := Yi CiutVtcestNumVtxOut+I+J :. Z := Z; AvDepth : - AvDepth + Z; end, AvDept-h := AvDepth / NumPts. Out.VteesCNumVtxOiJt+J II. Z :■ AvDepth, J : ~ < > ; ( ** initialize for insertion s e a r i I :» (NumDi splay + 1) div 2; K *) NurnDi sp.L ,?.y; while (J O I) do <* binary search for insertion point *) it AvDepth < GutVtcesI. Out.Pol ysC 1 1. Start. 1.1 then begin K := I; I := ( I + J ) dlv 2; end else begin J : « I ; I:=(I+K+l)div2l end; for J: =NumDi splay down to 1+1 do begi n OutPolyst.J+i J. Start ;= Ou tPolysCJl. Start; u u tP o 1 y s t J+l 1 N urn V t. x ■ = u tP o 1 y s [ J 1 . N urn V t x ; end; OutPolys! 1 + 1 J Start. ;= NumVtxOut + li OutPolysCI+U, NumVtx: = NumPts; NumVtxOut := NumVtxOut + NumPts + 1; NumDi spj ay - NumDi splay + 1; end, C* I nsertSort *) ( « +++++++++ ++++++++++++++ ClipOut H--I- + + + + + + H- + + + + + ++++++++++++ + H- ») procedure ClipOut.f Poly : OnePoly; var NumPts : Vertex; Place ; counter"), var Ir Lstl, NumDrawn ; counter; Ptl, Pt2 : Point; Drawn : boolean) (# ++++++++++++++++++++ ClipAfter ++++++++++++++++++++++ #) procedure CI i pAf ter ( Index : counter; Ptl,pt,2 ; Point); var I counter; Dl, D2, A : real; Out : boolean; Pt3 : Point; begin (* recursively check polygons for overlap with input edge #) if Index < Place oi- is polygon closer than edge? #) then with Out.Pol ysl I ndexl do begin I : = Start + NumVtx; Out : --- false; repeat <# for each polygon edge *) Dl := DotProdl P t.i , OutV tcesT I 1 )j U2 : = DotProd( pt.2, uutVteesLi:i ), if 101 <= 0. 0) and ( D2 <■ 0. 0) then begin (# both points visible #> Out := true; ClipAfter( I ndex+1 , P ti , Pt2 >; end else if Dl * U2 < O. then begin ( * one point visible *) A : «= Dl / (HI - D2); Listing 1 continued on page 300 Nestar Is Growing a Local Network for You. Centralized data processing is under pressure. Managers compete for computer time and complain about the lengthy justification process for new applications. Individual users at their terminals are frustrated by unacceptable response times. When the system goes down, everybody's DP-dependent work grinds to a halt. High Productivity Nestar's Cluster/One, Model A is a local network of Apple" computers that lets people get on with productive work instead of waiting in line, Since every user station is a computer in itself, response time is fast, and downtime problems are restricted to single individuals. The net result: produc- tivity grows as your network grows. More for Less Nestar's Cluster/One is a true local network, not merely a limited function shared disk system. This means your company enjoys the benefits of shared data, station-to- station communication (including electronic mail), and the reduced costs of shared peripherals. Since Cluster/One is " Apple is a registered trademark of Apple Computers. Inc. Circle 195 on inquiry card. microcomputer-based, its cost-per-station is dramatically lower than other systems with similar capabilities, includ- ing mini-based systems. And the more people on the net- work, the greater your savings! We're Growing Our List of Applications Cluster/One is working right now — in banking, manufac- turing, the travel industry, schools, and many other institu- tions and businesses. Software for the application you have in mind may also exist right now — literally thousands of programs have been written for Apple. Plant One Now! We're ready to ship immediately. So if you're working on the problems of DP overload, consider the Cluster/One from Nestar. It's a solution that grows on you. For more informa- tion, contact us at: Nestar Systems, Inc., 2585 East Bayshore Road, Palo Alto, CA 94303, 415/493-2223 AESEV? Circle 196 on inquiry card. Mil stocks 'em all for faster delivery. 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New York/Cleveland. Ohio. N.Y.: 516/482-3500 & 212/895-7177 800/645 8016. Ohio: 216/464-6688 Listing 1 continued: pt.2. Z: --1: end. Fas. X : = A * F't2. X + (1. O-A) * Ptl. X; Pt.3. Y : = A # Pt2. Y + (1. O-A) * Ptl. Yj Pt3. Z :- A * Pt2. Z + (1. O-A) * Ptl. I, i f i.ii < o. o then bag in C* Ptl visible *> ClipAfterC Index+1, Ptl, Pt.3 )• mi th Pt.3 do begin Ptl. X:*-Xi Ptl. Y:=Y; Pt end else begin (* Pt? visible ») C 1 i pA f ter ( I n d e x+ 1 , P 13 , P 12 ) . with Pt.3 do begin Pt2. X:«Xi Pt-2. Y: =Y; end: endl (* one point visible *> I := I-li until Out or (1 = Slfrtli <* all visible or edge end else begin f# reached end of list of closer polygons Makaflisplayabiel Ptl >; MakeDisplayable< Pt2 ) Movetoi Ptl. X, Ptl . Y h Drawtoi P t2. X , P t,2. Y )i Drawn := true; ( * mark as displayed #) end; end, (* ClipAfter *) (* ClipUut procedure body #) begin (* clip each poly edge by all closer polys, draw whats left #) MumLirawn : = Oi L si, I : » NumPtsi for !:-! to NumPts do beqi n with PolyCLstl 3 do begin Ptl. X: -Xi Ptl. Y: =Yi Ptl. Z:=Zi endi with PolyLlJ do begin Pt2. X:=X; Pt.2. Y: =Yi Pt2. Z: »Zl end; Ilrawn : « fai sei ClipAfterC l,Ptl,Pt2 ); <» check closer polys, then display ») if Drawn then NurrrDrawn :- NumDrawn + 1; LstI : = li end; <» for loop *) if NumLirauin = O then NumPts : =- O; (* mark as hidden *) end; (# Cli puut #) begin (» MakePi cture procedure body ») GetEyeSpacei EyePt, Cn tr I nt ); (* get eyespace matrix *) NumDisplay : «• 0; NumVtxOut. :- O; (* set. output counters *) f or I : = 1 t o N umP 1 s d o mi th Pol ygonsCIJ do beg i n for .J: > I to Nun.Vtx do (* get. polygon #) b e g i n with Point si. Vertices! Start + J 1 1 do begin ImpPolyE JJ. X: =X; rmpPol yC.J:. Y: =Y; TmpPol yt Jl. Z : -Zi end Transform* ImpP'oJ y[..l], tyeSpace, lmpPolyCJJ ); !* transform *) end; if PscesbyeC TmpPoly ) then begin' NumClp := NumVtxi (* protect original data #) Clipln( CmpPoly, NumCl p ); (# clip to view window *) if NumClp > then J nsert.Sort ( TmpPoly. NumClp ); <# store in sorted order for display #) end, end; ( * loop for each polygon #) (tt display surviving polygons, clipping each by closer polygons *) Start; ( * initialize and clear display ■» ) f o r I : = 1 to NumDisplay d o wi th OutPolysCI] do b e g i n for J:=l to NumVtx do with Gut.Vt.cesf. Start + J 1 do begin TmpPoiyCJX X: =Xi TmpPolyLJJ. Y: =Y; TmpPolyLJl. Z: =Z, end; ClipOuU TmpPoly. NumVtx. I ); (* clip and display *) if NumV t x > t h e n b e gin GetPlanesC 1 mppoly. NumVtx ), (* convert to planes #) for J: «1 to NumVtx do <* copy back for later clipping * ) with OutVtcesL Start + ...I 1 do begin X: =TmpPolyCJ3. Xi Y: =lmpPoly[.Jl. Y; 7 : =TmpPolyL.JJ. 7.; end; end; end; (* for loop <1 to NumDisplay) ») Finish; (* finalize picture #) end; (» MakePicture *) begin (# main program #) Initialize; (# set up default view parameters #) w h i 1 e n o t one d Listing 1 continued on page 302 300 April 1981 © BYTE Publications Inc Move Up to Tarbell The Serious Business Machine Do you have a small computer system that operates with mini-floppies and has limited storage capacity? Then it's time to move up to the Tarbell Empire Series System. Tarbell starts where small systems leave off, providing storage from 1 to 20 megabytes. This means Tarbell is capable of growing right along with your business. (It also makes sense to start with Tarbell if you're a first- time computer buyer.) Tarbell is the serious general purpose business machine, backed by years of experience with disk systems. It gives you word processing, inventory control with bill of materials, mailing lists — all in addition to accounting applications: general ledger, payables, receivables, payroll with cost accounting and order entry. Whatever your need may be, Tarbell can provide the working software that gets the job done. With the Tarbell System you get a Z80 4 Mhz CPU with memory management, timer and full interrupt capability, 2 RS-232 serial ports with handshaking, 64 K bytes of random-access memory, double density floppy disk interface, 2 double density floppy disk drives, cabinet, power supply, and cables. The software includes: CP/M™ 2.2 disk operating system, Tarbell Disk BASIC, Tarbell Database System, and all manuals and documentation. Tarbell also offers the MP/M™ Multi-User Operating System and 4 additional RS-232 serial ports. The Tarbell Empire Series is delivered assembled, tested, and with a FULL six-month warranty on parts and labor. And when you need even more mass storage, Tarbell also has a hard disk that's system- compatible and provides easy back-up. If your business is growing or you need more than a few hundred K bytes — it's time to move up to Tarbell. Call your local Tarbell dealer for competitive prices. The One-Stop Shopping Service 950 Dovlen Place, Suite B Carson, CA 90746 (213) 538-4251 CP/M and MP/M are trademarks of Digital Research Circle 197 on inquiry card. BYTE April 1981 301 Listing 1 continued: b e g i n nin tel n( -Tread object, eyepoint, center of interest, start over. , -' Hi l n d cm , pic t urs, q U 1 t 1 ' ) i read! n (CrcidChar ) ; case Cm dC h a r o t -r' begin writef'fils name : '); readl n(Fi 1 eName) i ReadObject (Fi leName;; end; -e- i begin wri te( ■' eyepoint, X Y Z : -' ) i with EyePt do readlni X,Y, Z ); end; ■- c ■' t. e 9 i n '...' r i t e ( -' c. e n t. e r o f i n t • r e 3 1 , X Y ? : ' ) ; with Cntrlnt do readln< X, Y, Z ), end; -s' -. begin NumPols ■. - 0; IMumPts :- Oi end; 'W begin write< 'display window : how many sides? '); r e a dl n ( W i n d owS i z e ) ; for I: =] to Windows'] ?e do b e o i n write<-'X Y > : ' ) ; w i t h W i n d cw C I : d o r a a d 1 n I X , Y , t > . end; CietScreenScale; <# get window to screen scale *) GetPlanesI Window, Wi ndowSi 26 ); i# get clipping plane end; -' p ' ■ Ma k eP i c t u r e ; -' >:j- : Done : = true; end; (# case statement ») end; (* while loop #) end. (* ruein program *) BYTE's Bugs Adventurous Bugs As expected, many people called our offices with ques- tions about the two Adven- ture programs in the December 1980 BYTE, "Pirate's Adventure" (by Scott Adams, page 192) and "Lost Dutchman's Gold" (by Bob Liddil and Teri Li, page 268). Although the authors found only two errors per se, the following notes are in order: In listing Adventure," 1240 says: 2 of "Pirate's page 210, line 1240 IF D O-ITHEN 1330 ELSE INPUT "READY DATA TAPE. HIT ENTER"; K$ while line 1330, the last line given in the listing, says simply: 1330 REM Photo 1: Jon Swanson, BYTE drafting editor, finds a bug (shown in right hand) at the entrance to the Lost Dutchman Mine. According to Scott Adams, the listing is correct as stands, because D is set to — 1 in line 20 of listing 2 (page 202) to denote a cassette-based pro- gram. The lines following line 1330 were deleted by Scott from an earlier version of the program, because they re- ferred to disk commands only. Thus, the variable D should retain the value —1 throughout this program, thereby preventing a branch from line 1240 to line 1330. There is an error in "Pirate's Adventure," but it affects you only if you tried to combine listings 1 and 2 in- to a single program for a 32 K-byte TRS-80 (as sug- gested in column 2 of page 212). The problem occurs when statements in what used to be listing 2 try to read the data directly from the DATA statements that used to be in listing 1. The full directions are: 1. Delete lines 6510 to 6790 of listing 1. 2. Append the remaining DATA statements from listing 1 to the end of listing 2, changing all occurrences after line 1240 of INPUT #D to READ. 3. In listing 2, change line 1280 to: 1280 FOR X = 0TO CL:FOR Y = 0TO 1:READ CA(X,Y):NEXT Y,X 4. In listing 1290 to: 2, change line 1290 FOR X = TO NL:FORY=0TO 1:READ NV$(X,Y):NEXT Y,X In the listing for "Lost Dutchman's Gold," the lack of a closing quote at the end of line 36 (page 268) caused some confusion. However, the program will run without the quote, so that is not a problem. One occurrence of the invisible Control-D that editor Gregg Williams missed mentioning is on line 4130 (page 280), just before the first letter in the word DELETE. The error in "Lost Dutch- man's Gold" is in the last line of line 1287 (page 274). Change the part that reads "7$(J,3)" to read "O$0,3)"- the character before the dollar sign is capital O. Thanks to Bob Liddil, Scott Adams, and several other BYTE readers for call- ing these problems to our at- tention. ■ 302 April 1981 © BYTE Publications Inc computer Li products, inc. NEW LOCATION 1198 E. Willow Street Signal Hill, CA 90806 Toll Free (800) 421-7701 Outside Calif. (213) 595-6431 Inside Calif. ORDERING INFO Name, address, phone Ship By: UPS or Mail Shipping Chrg. Add $2.50 up to 5 lbs. (UPS Blue) U.S. Mail Add $1.50 (U.S. Only) ($25.00 Minimum Order) TERMS We Accept Cash, Check, Money Orders, Visa & Master Charge (U.S. Funds Only) Tax: 6% Calit. Res. COD's & Terms Available on Approval (School PO's Accepted) MICROBYTE S-100 BOARDS S.D. SYSTEMS CALIFORNIA COMPUTER® iMICROPROCESSORSl IEEE S 100 Bus SlanlarO -Z 80A CPU (4MH/ version t Ihe Z BOi •158 instructions — supersei or aid upward compal.tJln Prom Ihe 8080 •. 78 instructions ■ Up to 4K of on bOVd Eprorn wlh cplionai Z80 monitor croc-ram _ i«<2708) !K|2716ior «Kt2732i •Full vecloreo intflirup! capability - 6 bit wild MNI II Dill ■2MHz or 4MH; ope'at>o" is jumper ■Se e:;j::t auio *a>I state insertion Z-80A/I-O $349.00 Assembled & Tested Optional Monitor Program $50.00 .(lrom5CM9.2CQn laraNol HO port-l S Intel 8255A MICROBYTE Disc Controller $389.00 Assembled & Tested CPM Available (Optional) MICROBYTE . avDC ■ - 16VOC I - 16VDC | 64K RAM Board Assembled & Tested Call for Price MICROBYTE ad RS-SaaC Serial Pons i nA Current Loop Porl Hy IEEE S lOOBusComp; IrZaOA-DarutMi or S.ncnr •Fun Set ol including F gura ■HH I/O Board $289.00 • I/O Servicing tn.itonmen! 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(3) Receiver Overrun Error Assembled & Tested ATARI 800 (NEW 16K VERSION) ■COMPUTER CONSOLE -OPERATORS MANUAL • ATARI BASIC 8K RAM «RF MODULATOR >57 FULL STROKE 'POWER SUPPLY ALPHANUMERIC KEYS * ADDED OPTIONS PLUS 4 FUNCTION KEYS'JOYSTICKS • INVITATION TO PRO- -EDUCATION ROM GRAMMING CASSETTE (NO CHARGE) CALL FOR PRICE 10% OFF SOFTWARE WITH PURCHASE EXPANDORAM I 2MHz DYNAMIC RAM BOARD KITS EXPANDORAM II 4 MHz DYNAMIC RAM BOARD KITS 16K 32K 48K 64K 16K 32K 48K 64 K $249.00 $275.00 $299.00 $325.00 $260.00 $285.00 $310.00 $335.00 $299.00 SBC-100KIT 2.5 MHz/Z-80 CPU WITH SERIAL & PARALLEL I/O PORTS SBC-200 KIT $325.00 4 MHz/Z-80 CPU WITH SERIAL & PARALLEL I/O PORTS VDB-8024 KIT $380.00 80x24 I/O MAPPED VIDEO BOARD WITH KEYBOARD I/O 2016 16K STATIC RAM BRD. 2032 32K STATIC RAM BRD. 2065 64K DYNAMIC RAM BD 2116 16K STATIC RAM BD. 2200 MAINFRAME 2400 MINI-8100S 2422 DISK CONTROLLER 2501 MOTHERBOARD 2710 4-PORT SERIAL I/O 2718 2 SER. PORT & 2 PAR. 2720 4-PORT PARALLEL I/O 2802 6502 CPU BOARD 2810 Z-80 CPU BOARD 5400 MINI-8100 5416 THE-8100 CALL FOR PRICE & DELIVERY VERSAFLOPPY I KIT $250.00 DISK CONTROLLER FOR 8" &5'/4" DRIVES S-100 BUS COMPATIBLE 4116's (200NS> (APPLE, TRS-B0, HEATH, ETC.) 8 for $26.00 16-49 pes. 3.00 50-99 pes. 2.85 100-499 pes. 2.60 500 Up 2.40 2114 L-2/200 NS VERSAFLOPPY II KIT NEW DOUBLE DENSITY DISK CONTROLLER FOR 8" & 5%" DRIVES $350.00 PROM-100KIT $210.00 S-100/EPROM PROGRAMMER FOR 2708, 2716, 2732, 2758 & 2516(TI) ALL BOARDS ARE AVAILABLE (ASSEMBLED & TESTED) CALL FOR PRICE & DELIVERY (SYSTEM SOFTWARE) AVAILABLE UPON REQUEST) 1-16 17-49 50-99 100-499 500 Up $3.60 ea. $3.40 ea. $3.25 ea. $3.00 ea. $2.85 ea. COMPONENTS 74LS240 1.35 ea. 74LS241 1.25 ea. 74LS244 1.25 ea. 74LS373 1.50ea. 74LS374 1.50 ea. 8T245 1.50 ea. ATARI OPTIONAL ACCESSORIES MODEL// DESCRIPTION PRICE 810 Disk Drive System $ 499.00 815 Disk Drive System $1199.00 820 40-col. Dot Matrix Printer $ 349.00 822 40-col. Thermal Printer $ 349.00 825 80-col. Dot Matrix Printer $ 750.00 830 Acoustic Modem $ 159.00 850 Interface Module $ 175.00 CX853 16K RAM Module $ 140.00 410 Cassette Recorder $ 60.00 ATARI SOFTWARE & ACCESSORIES Description Price Basketball $30.00 Super Breakout $30.00 Chess $30.00 Video Easel $30.00 3-D Tic Tac Toe $30.00 Star Raiders $42.00 Music Composer $42.00 Educational Sys. ROM $19.95 Assembler/Editor $45.00 Telelinkl $19.95 Description Space Invaders Kingdom Blackjack Biorhythm Graph It Energy Czar Mailing List Statistics I Paddle Controls Joysticks (pair) Price $15.95 $12.95 $12.95 $12.95 $15.95 $12.95 $16.95 $16.95 $17.95 QUME DT-8 DISK DRIVE • Double-sided/Single-Double Density • IBM-compatible/1.2 Mbytes/Disk • Fast — 3 ms. Track to Track •154 Tracks/Daisy Chain 4 Drives •ISO Standard Write Protect • Programmable Door Lock CALL FOR PRICE & DELIVERY $17.95 SA801 R 8" Single-Sided Single/Double Density CALL FOR PRICE & DELIVERY CENTRONICS 737-1 ANADEX DP8000 ANADEX DP9500 ANADEX DP9501 TEXAS INST 810 BASE 2 800 MST CALL FOP PRICE & DELIVERY MONITORS AMDEK 100 12" B&W $129.00 SANYO VM5012 12" B&W $260.00 AMDEK 13" Color $375.00 IN STOCK l.'.M.H.'.M NOVATION CAT 300 BAUD, AUTO ANSWER/ACOUSTIC $149.00 ea. NOVATION D-CAT 300 BAUD/DIRECT CONNECT $169.00 ea. (OPTIONAL RS232 CABLE $22.00) Verbatim 5 W (soft) Scotch 5 1 A" (soft) Scotch 5'/4" (10-sec) Scotch 5 '/, " (16-sec) Memorex 5Vt" (soft) Scotch 8" DS (soft) Maxell 8" DS/DD Part It MD525-01 744-0 744-10 744-16 3421 743-0 FD-2D Price Box of 10 $26.50 $33.00 $33.00 $33.00 $24.00 $49.95 $65.00 8080A 2.50 Z80A 10.00 Z80 CTC . . . 8.95 2708/450 NS $5.50 ea. or 8/$42.00 2716/5 VOLT $8.75 ea. 450 NS. Major Mfg. lilWJ liUdia 320T5 . . 80 320T12 . 80 340T5 . . 70 340T12 . 75 78L12 .25 RS-232 CONNECTORS DB25P DB25S 1-9 2.90 3.80 10-24 2.75 3.70 25 Up 2.40 3.60 Data Phone Hood 1.00 LO-PRO SOCKETS 100 Up .09 .11 .13 .21 .24 .28 14 PIN .10 16 PIN .12 18 PIN .15 20 PIN .23 24 PIN .26 28 PIN .30 40 PIN .40 .38 (BURNDY/TIN SOLDERTAIL) CAPACITORS .1 @ 12 Volt Ceramic 9c ea. or 100/$8.00 CONNECTORS 100 PIN IMSAI GOLD/S-100 SOLDERTAIL $2.40 ea. or 10/S2.25 ea. NEW16K RAM MODULE FOR ATARI 800 COMPUTER SYSTEMS $99. 95 ea. Mfg. by asap MAIN/FRAME & DISK DRIVE CABINETS from INTEGRAND MODEL X5 - Desktop Mainframe - 5 Cards - Small Powar Supply S200 Cabinet size 9 4"w x 16"d x 7 5"h Cabinet painted dove grey, front panel is black No optional colon! S-postion motherboard. 5 connectors installed, card cage with all guides Reset switch on front panel Power switch. 4 D825 cutouts. 1 BNC mounting hole. 70CFM fan. EMI filter. 6' power card, line luse. and clamped Nat cable exit on rear panel PX/5 power supply ( + fl@10A. + 16@1.5A, -16@1.5A). Power supply is a removable module. MODEL 7000 - Horizontal Desktop Disk/Cover - 2 Eight Inch Drives - Drives Horizontal $250 Cabinet size: 20"w x 23"d x 7.5"h. Cabinet painted dove grey, Irani panel Is black Mounting lor 2 eight-inch Shugan SAB01R Floppy Disk Drives (or mechanical equivalent) Drive mounting brackets supplied. Drives not supplied. 70CFM1an, 6' three-wire line cord, power switch, line fuse, EMI litter and clamped Hat cable exit on rear panel P794 power supply: + 5{5?4A. +24@5A-6A peak. -5(3. 75A All voltages regulated Powef supply is a removable module MODEL 800D — Desktop Main/Frame - 15 Cards - Standard Power Supply $255 Cabinet size: 17"w x 20.5"d x 7.5"h. Cabinet painted dove grey, troil panel is black (other color schemes optioial) 15-position IEEE compatible motherboard (will accept T80I terminator kit. optional), card cage with all guides Resel switch □n tront panel Power switch, 8'DB25 cutouts, 2 BNC mounting holes. 70CFM (an, EMI filter. 6' power cord, line fuse, and clamped Mat cable exit on rear panel PBOO power supply ( + 8<315A. +16@3A. -16<33A) Power supply is a removable module Motherboard connectors optional MODEL 7000S - Vertical Desktop Disk/Cover - 2 Eight Inch Drives - Drives Vertical $250 Cabinet size 13 5"w x 23"dx 11 "h Cabinel painted dove grey, front aanel is black Mounting lor 2 afght-tlKh Shugan SA8Q1R Floppy Disk Drives [or mechanical equivaleni). Drive mounting brackets supplied Drives not supplied 70CFMlan. 6' three-wire line cord, power switch, line fuse. EMI filter and clamped flat cable en! on rear panel P794 power supply + 5f!i4A, + 24@5A— 6A peak. -5@ 75A All voltages regulated. Power supply is a removable module Circle 198 on inquiry card. BYTE April 1981 303 TOLL FREE OUTSIDE CAL 1(800)421-0347, 1(800)423-5886 C* commodore Call for latest price on: 8000 isiness computer CBM 2001 Business computer CBM 2001 PET CBM 2022 Printer CBM 2023 Printer CBM2040 Dual Drive Floppy Disk CBM 8050 Dual Drive Floppy Disk \<^o v 1(800) Here is THE computer from NEC. Centronics and RS232 interfaces are standard. Up to 64 K (RAM). SEND FOR PRICE AND INFO., OR CALL TOLL FREE! monitors 9" Black and white. Only $185. Also available In Sanyo 12" Black and white. 15" Black and white. TRS-80' apple II & II plus is here Call today and be th first to have the most powerful professional computer in its class 1 All TRS-80 Compatible Hardware and Software. Call us and tell uswhat you need! THS 80 isa trademark of Tand; print wheels and thimbles Huge selection for Qume, Diablo, NEC. Plastic or metal. Call 1-800-421-0347. apple cards Hi-Speed Serial Interface Communications Interface Parallel Printer Interface Centronics Printer Interface Hobby /Prototype Integer Basic Firmware Applesoft Firmware III ATARI 825 V,N> Printer..$799 Call Call Call Call Call Call Call NEC Letter quality high speed printer, bi- directional, high resolution plot- ting, graphics. RO with Tractor Feed $2865. KSR with Tractor Feed $2995. Paper Tiger (1P440) $949. With Graphics Anadex DP9500 $1449 DP8000 $849. Epson MX 80 $645. jestk CALL FOR FREE CATALOG Everything that 400 has plus Basic Language Cartridge. 16K memory (ex- pandable to 48K). Onty $798. $* Bonus 8K Memory Module good till & 12/31/80. Atari Program Recorder. Only $68.95 Atari Expansion Memory. 8K $89.95 16K $159. ¥fc apple II inventory control system The lirst truly professional system that can tackle up to 8,100 items, transaction register/audit trail, in- ventory status report, re-order report, keeps track of purchase orders automatically, will handle multiple departments or divisions, fast data retrieval. Minimum hard- ware requirements; Apple II Plus with 48K, one disk drive and 80 column printer. Available also for the new DOS 3.3. dysan diskettes 8" (Box of 10) 374 0/1 sgl side/sgl density (4.50 •■. 3740/1 D sgl side/dbl den S8.95 ••- 5" (Bo« Of 5) 104/1 soli sector. 107/1 10 sectors, 105/1 16 sectors 14.50 ••. The HP-85 is a powerful BASIC language computer complete with keyboard, CRT c" ■ tape d Prices subject to change without notice. Please allow ample time for checks to clear. Please add 2% tor shipping and handling. California residents please add 6% sales tax. Sony, no COD. 16K RAM seioi aS39.95 ' EB Micromodem 100 Call. Micromodem II Only $325 In California Call 12131 996-2252 /MICRO BUSINESS WORLD 15818 Hawthorne Blvd., Lawndale, CA 90260 Immediate response to your orders U.S. and International Dealer inquiries invited. Technical Forum An ADM-3 Emulator for the Hazeltine 1500 Charles Shoemaker 2725 E Maplewood Ave Littleton CO 80121 All Hazeltine 1500 owners seem to agree on two things: it is a very nice terminal; and they are frustrated that a good deal of the software available that uses cursor con- trol has been written for the Lear Siegler ADM-3 ter- minal; consequently, it will not run properly on the 1500. In my particular case, the problem came to a head as I was attempting to modify for my terminal a graphics game written in 8080 assembly language. Some of the cursor-movement control was not at all obvious, and I wasn't really willing to take the time to follow the entire structure of the program through just to play a simple game. This, coupled with the fact that I'd have to do the same (disassembling system software where no source code is provided) for every program written for the ADM-3, led me to write this routine. This routine is a patch to my CP/M operating system BIOS (I/O driver module). It can be placed in ROM (read-only memory) or programmable memory, but, if it is placed in ROM, the two temporary locations, MODE and Y, will have to be relocated somewhere in program- mable memory. The routine is entered with the ASCII (American Standard Code for Information Interchange) character to be sent contained in the C register and the parity bit low. It assumes that the output status has been checked and that the output port is ready for a character. Registers A and C are altered on exit. Since this routine needs to send as many as four characters (I will explain that in a moment), there's a subroutine to wait for output status, which will have to be customized for other systems. If the character to be sent comes in another register, the MOV instructions to and from C (and the PUSH B and POP B instructions, if the register is B) can be easily altered. For example, if the program sends the character in A, the following routine can be used: PUSHB MOV C,A CALL EMULATOR POPB RET Note that in the 8080 instruction set, the PUSH B and POP B instructions also do the same to C. The code is twisty, and a little bit devious, as described below. I first attempted to fit it into 128 bytes, so that it would fit in one disk sector. Unfortunately, I didn't quite make it. Users with Z80 processors can take advantage of 304 April 1981 © BYTE Publications Inc Circle 199 on inquiry card. MICROBYTE INTRODUCES MORE PROFIT FOR YOUR BOTTOM LINE 32K STATIC MEMORY BOARD •Fully S100 bus compatible, IMSAI, SOL, ALTAIR, ALPHA MICRO • Uses Intel low-power 2141L-4 4Kx1 Static RAM •2 MHz or 4 MHz operation •Gold contacts for higher reliability •Thermally designed heat sink (board operating temperature 0-70 °C) •Commercially designed power bus; 7 ground bus bars; 0.1 uf decoupling capacitors • Fully tri-state buffered • Inputs fully low-power Shottky Schmitt Trigger buffered on all address and data lines • Phantom is jumper selectable to pin 67 •Each 4K bank addressable to any 4K slot within a 64K boundary •4K hardware or software selectable • One on-board 8-bit output port enables or disables the 32K in 4K blocks •Selectable port address • 4K banks can be selected or disabled on power on clear or reset •Will operate with or without front panel •Compatible with Alpha Micro, with extended memory management for selection beyond 64K • No DMA restriction • Low power consumption 800mA • Fully warranted for 120 days from date of shipment iiiiiiiiiiiitiiiniiiiiiiiiii Z-80A/I-O •A complete single board Z-80A CPU with serial/parallel interface •Fully compatible with the proposed IEEE S-100 Bus Standard •Z-80A CPU (4MHz version of the Z-80) •158 instructions— superset of and upward compatible from the 8080's 78 instructions •Up to 4K of on board Eprom with optional Z-80 monitor program — 1K(2708), 2KI2716) or 4K(2732) • Full vectored interrupt capability •2MHz or 4MHz operation is jumper selectable •Selectable auto-wait state insertion for extending M1*, MREQ* IORQ* and/or on board ROM •Dual RS-232 serial I/O ports using the Z80A-DART with individual baud rate selection (16 baud rates from 50-19,200 baud) •Up to 24 bit parallel I/O port— fully programmable Intel 8255A • Up to 8 separate counter/timers using 2 Z-80A CTC Ipf I DISK CONTROLLER •DMA to within 16M byte of memory •State-of-the-art NEC765 LSI Controller •IEEE-S100 compatible • DMA arbitration allows use of multiple boards within a system •PLL data recovery for totally reliable operation •Write pre-comp switched at mid-disc for reliable double density operation •Supports up to four (4) drives • Power On, Power Off or Reset deselects drives to avoid damaging files • Drive deselect Time Out, deselect drives not in use •Single or double sided operation •Single density/double density operation •8" standard drives •Separate Vqc supply for data recovery to eliminate possible noise problems WmMIMMW^ TftnWftiwmlmf 64K DYNAMIC RAM BOARD •Fully S-100 bus compatible/Alpha Micro compatible •64K x 8 bit dynamic RAM •Low power: + 8VDC @ 700 ma + 16VDC @ 100 ma -16VDC @ 25 ma • Built-in-parity with LED indicator and vector interrupt •Memory addressable in four 16K banks •Hidden refresh •Gold contacts for high reliability •72-hour Burn-in •Memory mapped via DIP switch •Built-in programmable write-protect •Programmable control port for parity and bank control MICROBYTE has the products — from memory boards to complete S-100 systems, and we offer the rest of the value cluster — call today for the whole story on how you can become a Micro- byte dealer. 4 PORT I/O •Quad RS-232C Serial Ports, One 20mA Current Loop Port •Fully IEEE S-100 Bus Compatible •Asynchronous Communications with Z80A-Dart(TM) or Synchronous Communications with Z80A-SIO/0(TM) • Full Set of Modem Control Signals, including Rl (Ring Indicator) • Easily Configurable to Any Type of Terminal Interface •I/O Servicing Environments: (1) Polled; (2) Bus Vector; (3) Z80 Mode 2 Vector •Off-Board Interrupt Daisy Chain Capability •Special Receive Conditions: (1) Framing Error; (2) Parity Error; (3) Receiver Overrun Error • Baud Rates Selected Individually from 50 Baud to 300K Baud • 72 Hour Burn-In MICROBYTE 1198 E. Willow St., Signal Hill, CA 90806«(213) 595-8571 Circle 200 on inquiry card. BYTE April 1981 305 Ad #12 SOFTWARE \S out our new items. CP/M users: specify disk systems and formats. Most formats available. CP/M' ARTIFICIAL INTELLIGENCE s Medical $449/$40 s Dental •. $449/$40 COMPLETE BUS. SYSTEM Creator $269/$25 Reporter $169/$20 Both $399/$45 COMPUTER CONTROL -" Fabs $159/$20 UltraSort II $159/$25 COMPUTER PATHWAYS Pearl (level 1) $ 99/S25 Pearl (level 2) $299/$40 Pearl (level 3) $549/$65 DIGITAL RESEARCH CP/M 2.2 NorthStar $149/$25 TRS-80 Model ll(P&T).$159/$35 Micropolis $169/$25 Cromemco $189/$25 PL/l-80 $459/135 • BT-80 $179/$25 Mac $ 85/S15 Sid $ 65/S15 Z-Sid $ 95/S15 Tex $ 707S15 DeSpool $ 50/$10 DYNAMIC MICRO- PROCESSOR ASSOC. S Ascom $ 1 09/$ 1 5 CBS $369/$45 ^DMA-DOS $179/$35 GRAHAM-DORIAN k« General Ledger $729/$40 * Acct Receivable $729/$40 v> Acct Payable $729/$40 C Job Costing $729/$40 Payroll $493/$40 Inventory $493/$40 Cash Register $493/$40 Apartment Mgt $493/$40 KEY BITS String/80 $ 84/$20 ■^ String/80 (source) $279/$na WordSearch $179/$25 MICRO-AP S-Basic $269/$25 Selector III $269/$25 Selector IV $469/$35 MICRO DATA BASE SYSTEMS HDBS $269/$35 MDBS $795/$40 s DRSorQRSor RTL . $269/$35 k- MDBS PKG $1295/$60 MICROPRO WordStar $324/$60 S Customization Notes. .. .$ 89/$na Mail-Merge $114/$25 WordStar/Mail-Merge. . . $434/$85 s DataStar $249/$60 WordMaster $119/$40 SuperSort I $199/$40 MICROSOFT Basic-80 $294/$30 *•" Basic Compiler $329/$30 v Fortran-80 $349/$30 CobOl-80 $574/$30 Macro-80 $144/$20 Edit-80 $ 84/$20 MuSimp/MuMath $224/$25 MuLisp-80 $174/$20 ORGANIC SOFTWARE TextWriter III $111/$20 DateBook $269/$25 OSBORNE General Ledger $ 59/$20 Acct Rec/Acct Pay $ 59/$20 Payroll w/Cost $ 59/$20 • All 3 $129/$57 All 3 + CBASIC-2 $199/$71 PEACHTREE" General Ledger $399/$40 Acct Receivable $399/$40 Acct Payable $399/$40 Payroll $399/$40 Inventory $399/$40 Property Mgt $799/$40 CPA Client Write-up $799/$40 Mailing Address $349/$40 SOFTWARE WORKS Adapt $ 69/$na Ratfor $ 86/$na SOHO GROUP MatchMaker $ 97/S20 Worksheet $177/$20 STRUCTURED SYSTEMS GL or AR or AP or Pay . . . $599/$40 Inventory Control $449/$40 • Analyst $199/$25 • OSort $ 89/S20 SUPERSOFT • Forth (8080orZ80) $149/$25 • Diagnostic II $ 84/$20 Other less 10% TCS GLorARor APorPay. All 4 WHITESMITHS "C" Compiler Pascal (incl "C") .$ 79/$ 25 .$269/$96 $600/$30 .$750/$45 DATA BASE FMS-80 $649/$45 dBASE II $629/$50 Condor $599/$30 T.I.M $329/$35 "PASCAL" • Pascal/MT+ $429/$30 • Pascal/Z $349/$30 Pascal/UCSD $299/$30 Pascal/M $149/$20 "WORD PROCESSING" • SpellGuard $249/$25 Spell Binder $349/$45 • Magic Wand $289/$45 OTHER GOODIES" Tiny"C" $ 89/$50 Tiny "C" Compiler . . . $229/$50 CBASIC-2 $ 89/S15 Nevada Cobol $129/$25 MicroStat $224/$ 15 Vedit $ 99/$ 15 • Prof Time Bill (Asyst) .... $549/$40 • ESQ-1 $1349/$50 • MiniModel $449/$50 • StatPak $449/$40 • Micro B+ $229/$40 APPLE II MICROSOFT Softcard $292 • Fortran $179 Cobol $574 PERSONAL SOFTWARE Visicalc $122 CCA Data Mgr $ 84 Desktop/Plan $ 84 Zork % 34 PEACHTREE- General Ledger $224/$40 Acct Receivable $224/$40 Acct Payable $224/$40 Payroll $224/$40 Inventory $224/$40 "OTHER GOODIES Super-Text II $127 Data Factory $129 • DB Master $159 Ledger Plus $549 • Charles Mann less 15% • STC less 15% ORDERS ONLY-CALL TOLL FREE VISA • MASTERCHARGE 1-800-854-2003 ext. 823 • Calif. 1-800-522-1500 ext. 823 Overseas — add $10 plus additional postage • Add $2.50 postage and handling per each item • California residents add 6% sales tax • Allow 2 weeks on checks, C.O.D. ok • Prices subject to change without notice. All items subject to availability • (?) — Mfgs. Trademark. THE DISCOUNT SOFTWARE GROUP 6520 Selma Avenue, #309 • Los Angeles, CA 90028 • (213)666-7677 Te< im. their relative-jump capabilities and easily crunch it into 128 bytes. How It Works On the ADM-3, cursor up, cursor right, home, and clear screen are simple control codes: 11, 12, 30, and 26 in decimal, respectively. The control codes for the two ter- minals are shown in table 1. These codes are converted in the routine called NORM (see listing 1). Noncontrol char- acters are shunted to be transmitted directly at the label Listing 1: The Lear Siegler ADM-3 emulator for the Hazeltine 1500. For a detailed explanation of the program, see the accom- panying text. SPECL! 0UTCHS ORG JMP ORG LDA ORA MOV JZ JPE CPI MVI STA JNZ MVI STA RET CPI JC JNZ MVI JMP CPI JZ CPI JNZ MVI JMP CPI JNZ MVI STA RET CPI JNZ INR INR MVI CALL MOV PUSH IN ANI JZ POP GUT RET JM MOV STA MVI STA RET PUSH MVI CALL POP MOV SUI CPI JNC ADI CALL XRA STA LDA JMP HE DB 7FB4H ENTRY 8000H MODE A A,C NORM XY A,0 MODE ZAP 30 NTH0ME ZAP Cr 18 SPECL 11 SPECL-1 12 NTRGHT A. 16 ZAP 27 NTESC A.l MODE 26 DUTCH C C A, 126 ZAP A,C PSU 10H OUTCH+2 PSU 11H Y ArOFPH MODE C.17 SPECL 6 ArC 32 31 SENDX 96 OUTCH+1 A MODE Y OUTCH+1 FIX CPM DUTCH ROUTINE TO JUMP HERE PUT AFTER BIOS ARE WE IN THE MIDDLE OF SOMETHING? GET CHARACTER TO SEND. FOR COMPARES ORDINARY IF JUMP TAKEN, NORM CONTAINS EITHER 3 OR 255 MIDDLE OF XY ADDRESS SEOUENCE PRESET ERROR CONDITION SOMETHING'S WRONG — PRINT IT AND GIVE Up FIX UP TELL US NEXT TIME AND BACK TEST FOR HDME CHARACTER NOT A CONTROL CHARACTER — SEND IT GET HAZEL'S HOME CHARACTER- DO IT IS IT UP-CURSOR? QUICK TRICK IS IT RIGHT-CURSOR? NO HAZEL'S RIGHT-CURSOR IS IT ESCAPE-ADDRESS CURSOR? TELL US NEXT TIME THROUGH IS IT CLEAR SCREEN? NO, MUST BE SOME OTHER CONTROL CHARACTER MAKE 2B, HAZEL'S CLEAR SCREEN CHARACTER- GET HER ATTENTION SEND THE FIRST CHARACTER RIGHT AWAY RETRIEVE ORIGINAL CHARACTER STOW IT AWAY GOTTA CHECK STATUS GET IT BACK SEND IT FINALLY, RETURN TO CALLER WE KNOW WE HAVE 'ESC ' = ' SEQUENCE SEE IF THIS IS X OR Y CHARACTER TAKE THE JUMP IF THIS IS X JUST GET Y CHARACTER AND SAVE IT LET US KNOW WHAT TO DD NEXT TIME AND BACK SAVE X CHARACTER A MINUTE GET HAZEL'S ATTENTION GET'M BACK- GET X COORDINATE GET RID OF ADM-3 BIAS FIX HAZEL'S BIAS OK AS IS HAZEL LIKES THIS BETTER SEND X FIX MODE UP — BACK TO NORMAL ADM-3 BIAS OK FOR HAZEL SEND IT AND GO HOME 306 April 1981 © BYTE Publications Inc Circle 201 on inquiry card. dBASE II vs. the Bilge Pumps. by Hal Pawluk We all know that bilge pumps suck. And by now, we've found out— the hard way— that a lot of software seems to work the same way. So I got pretty excited when I ran across dBASE II, an assembly-language rela- tional Database Man- agement System for CP/M. It works! And even a rank beginner like myself got it up and running the first time I sat down with it. If you're looking for software to deal with your data, too, here are some tips that will help: Tip #1: Database Management vs. File Handling: Any list or collection of data is, loosely, a data base, but most of those "data base man- agement" articles in the buzzbooks are really about file handling programs for specific applications. A real Database Management System gives you data and program independence (no repro- gramming when data changes), eliminates data duplication and makes it easy to turn data into information. Tip #2: Assembly Language vs. BASIC: This one's easy: if you're setting up a DBMS, you're going to be doing a lot of sorting, and Basic sorts are s-l-o-w. Run a benchmark on a Basic system like S*-IV against a relational DBMS like dBASE II and you'll see what I mean. (But watch it: I've also seen one extremely slow assembly-language file management system.) Tip #5: Relational vs. Hierarchal & Network DBMS. CODASYL-like hierarchal and network systems, around since the 1960's, are being phased out on the big machines so why get stuck with an old-fashioned system for your micro? A relational DBMS like dBASE II eliminates the pre- defined sets, pointers and complex data structures of a CODASYL-type DBMS. And you don't need to be a programmer to use it. dBASE II vs. everything else. dBASE II really impressed me. Written in assembly language (with no need for a host lan- guage), it handles up to 65,000 records (up to 32 fields and 1000 bytes each), stores numeric data as packed strings so there are no round- off errors, has a super- fast multiple-key sort, and supports ISAM based on B* trees. You can use it interactively with English- like commands (DISPLAY 10 PROD- UCTS), or program it (so when you've set up the formats, your secretary can do the work). Its report generator and user- definable full screen operations mean that you can even use your existing forms. And if all this makes your mouth water, but you've already got all your data on a disk, that's okay: dBASE II reads your ASCII files and adds the data to its own database. Right now, I'm using dBASE II with my word processor for budgeting, scheduling and preparing reports for my clients. Next come job costing, time billing and accounting. An Unheard-of Money-Back Guarantee. dBASE II is the first software I've seen with a full money-back guarantee. To check it out, just send $700 (plus tax in California) to Ashton-Tate, 3600 Wilshire Blvd., Suite 1510, Los Angeles, CA 90010. (213) 666-4409. Test dBASE II doing your jobs on your computer for 30 days. If, for some strange reason, you don't want to keep it, send it back and they'll refund your money. No questions asked. They know you don't need your bilge pumped. AshtonTate ©Ashton-Tate 1980 Circle 202 on inquiry card. blTTE April 1981 307 CROSS-COMPILE FORTH ! Nautilus Systems' Forth Cross-compiler is now in use by individuals, universities, and major companies around the world. USES: • To produce a modified or tailored version of Forth on a host computer. • To produce Forth systems for computers that have none. • To produce applications that use the minimum required nucleus code. • To do all the above in a ROM/RAM environment. FEATURES: • Written entirely in high level fig-Forth. • Automatic forward reference to any word or label. • Cross-compiles to any location in the host for any base address in the target. • Cross-canpiles to any screen in the host for any base address in the target. • Cross-canpiles vocabularies. • Can produce headerless code. • Can produce romable code. • Load map that shows address, type of symbol and name. The map appears in readable column format, and page width and length are selectable. • A comprehensive list of undefined symbols is produced showing undefined CFAs, DOES> pointers, labels and words on a vocabulary-by-vocabulary basis. MACHINE READABLE VERSIONS FOR THE FOLLOWING SYSTEMS: TRS-80 NORTHSTAR APPLE CP/M H-89 LSI-11 Each includes an executable version of fig-FORTH model 1.0, Cross-compiler, cross-compilable source, utilities, and documentation. (This program is not intended for newcomers to FORTH) Price $150.00 (Includes shipping). Calif, residents please add sales tax. NAUTILUS SYSTEMS P.O. BOX 1096 SANTA CRUZ, CA. 95061 FOR THE SERIOUS FORTH USER TRS-80 is a trademark of Radio Shack, a division of Tandy Corp. APPLE is a trademark of Apple Computers Inc. CP/M is a trademark of Digital Research. LSI-11 is a trademark of Digital Equiptment Corp. COPYRIGHT ° 1981 NAUTILUS SYSTEMS HOST — TARGET Te< im, Action Cursor Up Cursor Down Cursor Left Cursor Right Clear Screen Cursor Home ADM-3 1 1 (Control-K) 10 (line teed) 8 (backspace) 12(Control-L) 26 (Control-Z) H-1500 126, 12 (-, Control-L) 10 (line feed) 8 (backspace) 16 (Control-P) 126, 28 (-, Control-shift-L) 30 (Control-shift-N) 126, 18 (~ , Control-R) Table 1: The control codes for the Lear Siegler ADM-3 and the Hazeltine 1500 terminals. The numbers are the decimal values for the ASCII codes shown in parentheses. ZAP. The control codes are detected with a series of com- pare operations, and the proper code for the Hazeltine placed in the C register. The Hazeltine's 126 function- lead-in code is sent, if necessary, by the jump to SPECL. Other control codes (carriage return, line feed, back- space, etc) fall through and are sent unchanged. The two-coordinate direct cursor addressing is more complicated. For both terminals, X is the horizontal posi- tion, from thru 79, and Y is vertical, from thru 23. The ADM-3 must receive the sequence ESC (ASCII 27), " = " (ASCII 61), Y + 32, and X + 32. The H-1500 requires the tilde (~ , ASCII 126), ASCII 17, then X, then Y + 32. In addition, if X is in the range thru 31, then 96 should be added, although the terminal will accept thru 31. The routine collects all four characters from the host software, then sends the Hazeltine control sequence. Since the emulator is called four times before it can com- plete the direct-cursor addressing sequence, we need some way to know where we are in the sequence and what action needs to be taken in each case. The tem- porary byte, MODE, is the key to what happens. Its four states are as follows: • MODE = 0: We are not in the middle of a direct- cursor-address sequence. NORM gets control. If NORM detects ESC, it sets MODE to 1 and returns. • MODE = l: ESC has been detected. If "=" is the cur- rent character, MODE is set to 3 and the routine returns. Otherwise, MODE is reset to and the char- acter is sent. • MODE = 3: This character is the Y coordinate. The byte is stored in variable Y, and MODE is set to 255. • MODE = 255: The byte to be sent is the X coordinate. The byte is processed for the Hazeltine and the lead-in and control bytes are sent. X is recovered and sent, then Y is recovered. No processing for the 1500 is needed here. MODE is reset to and Y is transmitted. These values for MODE were chosen so that a four- way branch could be taken from one test, the ORA A in- struction at the top of the routine. The zero flag is tested first, and the jump-on-zero instruction branches to NORM. The 1 condition is separated by the JPE, as it is the only condition with odd parity. The 3 and 255 are dif- ferentiated with the sign flag. The kind of multiway branching I've used here is worth a little study. It could be useful in a number of applica- tions.! 308 April 1981 © BYTE Publications Inc Circle 203 on inquiry card. Ahml ^mt mtk Licenced by Sinclair Research Ltd. ^_ Microcomputer for everyone at a Micro Price J* \ The LMicroficeJ The unique and valuable components of the MicroAce The MicroAce is not just another personal computer. Quite apart from its exceptionally low price, the MicroAce has two uniquely advanced components: the powerful BASIC interpreter, and the simple teach yourself BASIC manual. The unique versatile BASIC interpreter offers remarkable programming advantages: • Unique 'one-touch' key word entry: the MicroAce eliminates a great deal of tiresome typing. Key words (RUN, PRINT, LIST, etc.) have their own single-key entry. • Unique syntax check. Only lines with correct syntax are accepted into programs. A cursor identifies errors immediately. This prevents entry of long and complicated programs with faults only discovered when you try to run them. • Excellent string handling capability takes up to 26 string variables of any length. All strings can undergo all relational tests (e.g. comparison). The MicroAce also has string input to request a line of text when necessary. Strings do not need to be dimensioned. • Up to 26 single dimension arrays. • FOR/NEXT loops nested up 26. • Variable names of any length. • BASIC language also handles full Boolean arithmetic, conditional expressions, etc. • Exceptionally powerful edit facilities, allows modification of existing program lines. • Randomise function, useful for games and secret codes, as well as more serious applications • Timer under program control. • PEEK and POKE enable entry of machine code instructions, USR causes jump to a user's machine language sub routine. • High resolution graphics with 22 standard graphic symbols. • All characters printable in reverse under program control. • Lines of unlimited length. 'Excellent value' indeed! For just $149.00 {including handling charge) you get everything you need to build a personal computer at home... PCB, with IC sockets for all ICs; case; leads for direct connection to a cassette recorder and television (black and white or color); everything! Yet the MicroAce really is a complete, powerful, full-facility computer, matching or surpassing other personal computers at several times the price. The MicroAce is programmed in BASIC, and you can use it to do quite literally anything, from playing chess to managing a business. The MicroAce is pleasantly straightforward to assemble, using a fine tipped soldering iron. It immediately proves what a good job you've done: connect it to your TV ... link it to the mains adaptor ... and you're ready to go. Fewer chips, compact design, volume production-more power per Dollar! The MicroAce owes its remarkable low price to its remarkable design: the whole system is packed on to fewer, newer, more powerful and advanced LSI chips, A single SUPER ROM, for instance, contains the BASIC interpreter, the character set, operating system, and monitor. And the MicroAce 1K byte - a new generation of miniature computers A COMPLETE COMPUTER for $149.00 for 1K Kit Post and Packing FREE (Add 6% Tax for Shipments inside California) RAM (expandable to 2K on board) is roughly equivalent to 4K bytes in a conventional computer typically storing 100 lines of BASIC. (Key words occupy only a single byte.) The display shows 32 characters by 24 lines. And Benchmark tests show lhat the MicroAce is faster than all other personal computers. No other personal computer offers this unique combination of high capability and low price. The MicroAce teach-yourself BASIC manual. If the features of the BASIC interpreter mean little to you don't worry. They're all explained in the specially written book free with every kit! The book makes learning easy, exciting and enjoyable, and represents a complete course in BASIC programming from first principles to complex programs. (Available separately purchase price refunded if you buy a MicroAce later.) A hardware manual is also included with every kit. The MicroAce Kit: $149.00 with IK COMPLETE $169.00 with 2K Demand for the MicroAce is very high: use the coupon to order today for the earliest possible delivery. All orders will be despatched in strict rotation. If you are unsuccessful in constructing your kit, we will repair it for a fee of $20.00, post and packing FREE. Of course, you may, return your MicroAce as received within 14 days for a full refund. We want you to he satisfied beyond all doubt and we have no doubt that you will be. Z80 A microprocessor chip, widely recognised as the linsl ever made. Sockets for TV, cassette recorder, power supply, SUPER ROM. Your MicroAce kit contains... Printed circuit board, with IC sockets for all ICs. Complete components set, including all ICs-all manufactured by selected world leading suppliers. New rugged keyboard, touch-sensitive, wipe clean. Ready-moulded case. Leads and plugs for connection to domestic TV and cassette recorder. (Programs can be SAVEd and LOADed on to a portable cassette recorder.) Mains adaptor of 600 mA at 9VDC nominal unregulated. FREE course in BASIC programming and user manual. JOIN THE REVOLUTION - DON'T GET LEFT BEHIND - ORDER YOUR MICROACE NOW!! Send Check, Money Order or quote your Credit Card No. to: MicroAce 1348 East Edinger, Santa Ana, California, Zip Code 92705. or phone (714) 547 2526 quoting your Credit Card Number. Quantity Description Unit Price TOTAL MicroAce Kit 1K $149.00 MicroAce Kit 2K $169.00 Manual $10.00 1K Upgrade Kit $29.00 Shipmen add 6% ts inside California TAX TOTAL Amex. Diners Check Money Order Master Charge Visa Card No. Exp. Date_ Address- City .Zip. Circle 204 on inquiry card. BYTE April 1981 309 Technical Forum Challenger Writes on Comprint Edward H Carlson, 3872 Raleigh Dr, Okemos MI 48864 I use an Ohio Scientific C2-4P for word processing and text editing. I selected the Comprint 912 as a printer because of its legibility (9 by 12 dot matrix), speed (3 lines per second), quietness (electrostatic printing, not impact), and low cost. The choice of the parallel-interface model reduced costs further. I want to show you a 6502 assembly-language program that interfaces a 6522 VIA (versatile interface adapter) parallel port to the Comprint 912. The Model 500 main processor board of an OSI Challenger II has a provision for a 6820, a 6520, or a 6521 PIA (peripheral interface adapter) containing two 8-bit parallel ports. The 6522 VIA enhances the PIA functions with extra handshake options and two timers. I had already added a 6522 to my processor board in the space for the PIA. A little extra work was required because six pins have different functions on the 6522. I made the modification by changing only four lines on the Model 500 processor board. The price was a nonstandard nam- ing of the address lines to the sixteen registers of the 6522. The address conversions needed are noted at the bottom of listing 1. The 6522 resides at hexadecimal location F7xx in memory. The Comprint has several parallel I/O (input/output) options. I've used the wide strobe/ acknowledge mode, enabled by pulling a jumper pin from the Comprint cir- cuit board. Besides the seven lines of ASCII (American Standard Code for Information Interchange) data, there are three control lines. DAV is the strobe signal sent by the computer telling the printer that valid data is on the data lines. NDAC is the acknowledge signal sent by the printer telling the computer that the data has been ac- cepted. NRFD is the busy line that the printer sets high when its data buffer is full and unable to accept further data. At the 6522 end, the lines are assigned as follows: DAV is CB2, put high and strobed low when the 6502 pro- cessor writes data to port B of the 6522 VIA. It must be set high again before the next ASCII character is sent. NDAC is CBl, configured to detect the trailing edge, low-to-high transition, of the acknowledge signal sent from the printer. NRFD is pin PB7 of the eight-line parallel data. One wants to detect the high or low state of this line, not an edge as it makes a transition. Listing 1: After installing the 6522 VIA in the Model 500 processor board of the OSI Challenger II, this 6502 assembly-language pro- gram interfaces the 6522 parallel port to the Comprint 912. 10 cooo * = $CO00 20 COOO PARALLEL ' ' 30 COOO 48 OUTCHR PHA A CONTAINS CHARACTER 40 C001 A902 LDA #$02 ENABLE B PORT OF 6522 50 C003 8D0EF7 STA $F70E 60 C006 A97F LDA #$7F DATA DIRECTION 70 C008 8D08F7 STA $F708 80 C00B 8D07F7 STA $F707 CLEAR INTERRUPT FLAGS 90 C00E A990 LDA #$90 READY STROBE, PERIPHERAL CON 100 CO 10 8D03F7 STA $F703 CBl TO GO LOW ON WRITE, DAV 110 C013 AD00F7 BUSY LDA $F700 READ B PORT INPUT 120 CO 16 2980 AND #% 10000000 BIT 7 IS NRFD OF COMPRINT 130 CO 18 30F9 BMI BUSY BUSY IF BIT 7 IS HIGH 140 C01A 68 PLA 150 CO IB 49FF EOR #$FF INVERT, DATA ACTIVE LOW 160 CO ID 8D00F7 STA $F700 OUTPUT TO PRINTER 170 C020 AD07F7 ACK LDA $F707 LOOK FOR NDAC ON CB2 180 C023 2910 AND #$10 NDAC IS ACKNOWLEDGE FROM 190 C025 C910 CMP #$10 COMPRINT 200 C027 D0F7 BNE ACK IF NOT FOUND, LOOK AGAIN 210 C029 A9F0 LDA #$F0 RESTORE CBl TO HIGH, END DAV 220 C02B 8D03F7 STA $F703 230 C02E 60 RTS 235 C02F Standard Mine 240 C02F B Port I/O Register 00 00 250 C02F Auxiliary Control Register 0B 0E 260 C02F Peripheral Control Register oc 03 270 C02F Interrupt Flag Register 0D 07 310 April 1981 © BYTE Publications Inc Volume II CiarcicTs Circuit Cellar Steve Garcia, described as a "technological treasure," is BYTE's most popular writer. His in- novative circuit designs are ingenious, timely, prac- tical, easy-to-build, and — they work. Ciarcia's Circuit Cellar, Volume II is more than a series of hardware designs: it is a ready reference and workbook of related projects, now available as a single source. Volume II features 19 articles, including 14 that were voted by BYTE's readers as the best articles of the month, such as: Build a Computer-Controlled Security System, Communicate On a Light Beam (laser communications), Anyone Know the Real Time? (real time clocks), The Intel 8086, Add Non- volatile Memory to Your Computer, Computerize a Home (AC remote control from your computer), A Computer-Controlled Wood Stove, Ease Into 16-Bit Computing (The Intel 8088), and I/O Expansion for the Radio Shack TRS-80: Parallel and Serial Ports. Special offer: Buy both Volume I and Volume II now and get Volume I for one-half price. Offer valid through April 15th. All orders must be postmarked by that date. Volume I contains a collection of more than a year's worth of the popular series Steve writes for BYTE magazine. Included are six winners of BYTE's On-going Monitor Box (BOMB) award voted by the readers as the best articles of the month: Control the World (a four-channel digital-to-analog converter for controlling appliances and other devices); Memory Mapped I/O; Program Your Next EROM in BASIC; Tune In and Turn On (a computerized wireless AC control system); Talk To Me (add a voice to your com- puter); and Let Your Fingers Do the Talking (a touch panel for your video display). Buy these books at your favorite computer book- store or direct from BYTE. Use our toll-free number (1-800-258-5420) and order your copies today. Please send L! Please send I Please send I J . copies of Ciarcia's Circuit Cellar, Volume I, $8.00 . copies of Ciarcia's Circuit Cellar, Volume II, $12.95 . special offer— the complete set of Ciarcia's Circuit Cellar, Volumes I & II, $16.95 (Hurry-offer expires April 15, 1981) Name Title Company Street City State/Province Zipcode □ Check enclosed in the amount of $ □ Bill Visa □ Bill Master Charge Card No. Add 75 IRQ J Figure 1: The hardware modification that enables the Comprint 912 printer to work with the OS1 Challenger II. When the 682,0 posi- tion on the Model 500 processor board is modified to take the 6522 VIA, the four marked lines must be cut (the lines to pins 21, 22, 37, and 38, see figure la). New lines must be attached to these pins (denoted by asterisks in figure lb). Note the nonstandard address- line assignments after the rewiring is completed. AMS ADVANCED MICRO SYSTEMS • 26188 ADAMOR ROAD • CALABASAS, CA. 91302 OPEN MON.-FRI. 10-8 SAT. 10-6 Tel.: (213) 880-4670 COMPLETE QUALITY SYSTEMS AT LOW, LOW PRICES ! ALL SYSTEMS ALLOW UPWARD EXPANDABILITY AND INCLUDE: 1. TELEVIDEO 91 2C 2. ANADEX DP-9500 SERIES GRAPHIX PLUS PRINTER 3. 64K DYNAMIC RAM 5. PLUS ONE OF THE FOLLOWING DISK DRIVE SETS a. 2x5 1 /4" FLOPPY b. 2x8" FLOPPY c. 2x8" FLOPPY BYTES) (1M BYTES) (2M BYTES) FOR ■ FOR $5350. $5650. $6150. 4. DECISION I BASIC UNIT a. Z-80A CPU 4-TO-6 MHZ. b. 3 SERIAL & 2 PARALLEL PORTS. c. SUPERVISOR CONTROL !N H&S. d. REAL TIME CLOCK. e. MEMORY MAP. (400K FOR . 8" FLOPPY 5 1 /4" WINCHESTER (6MB) FOR $7750. Featuring f. PROGRAMMABLE INTERRUPT CONTROLLER. g. DIGITAL RESEARCH CP/M 2.2 O.S. h. MICROSOFT EXTENDED DISK BASIC, i. DISK CONTROLLER j. DOCUMENTATION. e. 8" FLOPPY 8" HARD DISK (11 MB)FOR $7960. f. 8" FLOPPY 14" HARD' DISK (27 MB) FOR $8995. SYSTEMS ARE DELIVERED AS AVAILABLE. PRICES, TERMS, SPECIFICATIONS SUBJECT TO CHANGE WITHOUT NOTICE. ALLOW 30-60 DAYS FOR DELIVERY. PRICE FOB CALABASAS, CA 91302. DECISION I - TRADEMARK OF MORROW DESIGN. PRICES ARE FOR PREPAID (DEPOSIT) ORDERS. 312 April 1981 © BYTE Publications Inc Circle 206 on inquiry card. SOFTWARE NEW! HISTOGRAPH (Boyd) A calendar-based histogram or bar-graph production system. Allows the user to enter numeric data that relates to a date, and reproduces that data as a high- resolution histogram. 09009. Apple II Disk. $29 95 NEW! DATA-GRAPH (Boyd) Aids in the preparation of graphs and charts. Numeric data can be entered into Data-Graph and used to create colorful one- , two- , or four-quadrant graphs. 09109. Apple 11 Disk. $49.95 NEW! DOUBLE PRECISION FLOATING POINT FOR APPLESOFTTM (S-C Software) Extends the accuracy of the arithmetic available on the Apple from nine digits to a full 21 -digit precision on all functions in Applesoft compatible format. 09409. Apple II Disk. $49 95 ORDER NOW! Hayden Book Company, Inc. 50 Essex Street, Rochelle Park, NJ 07662 Send me Ihe software checked below A check or money order is enclosed i understand that Hayden pays shipping and handling cosls and thai I can return any disk or tape within 10 days if il is defective or [ am dissatisfied wilh it for any reason Residents of NJ and CA must add sales tax Offer good in US only Name of indi- vidual ordering must be filled in B 4/81 a 07004 □ 07009 □ 07101 O 07103 D 07301 □ 08609 D 09009 D 09109 □ 09409 □ 09704 D 03403 D 03604 a 03404 a 03804 D 03408 D 03904 D 03409 D 04804 □ 03410 □ 04909 D 03414 D 05103 a 03440 D 05108 □ 03444 Q 05303 □ 03484 a 05308 □ 03504 □ 05903 Name Address City/State/Zip 81 009 Great software doesn't have to be hard to find. Just look for the Hayden name. NEW! OP-AMP DESIGN (Gabrielson) Provides the necessary values for your design and will suggest appro- priate op-amp types. Includes a choice of six op-amps, and the program will then determine if your selection of an op-amp will be acceptable within your chosen parameters Can be updated to accommodate future op-amps. 09704. Apple II tape. $16.95 LINE & VARIABLE CROSS REFERENCE GENERATOR (Johnson) Provides a cross-reference of line numbers and variable names. 07301. PET tape. $16.95 APPLESOFT UTILITY PROGRAMS (Gilder) Increase your BASIC programming speed and flexibility. Contains 9 useful subroutines: 1 . REM Writer 2. PRINT Writer 3. POKE Writer 4. Hexadecimal/Decimal Converter 5. Line Counter 6. Renumber 7, Append 8. Byte Counter 9. Slow List/Stop List 03504. Apple I! tape, $29-95 RENUMBER & APPEND: Utility Programs for the Apple (Gilder) Renumber your Applesoft program and append a second program to the one in memory. 03804. Apple II tape. $14 95 REVIVE (Gilder) When a program is accidentally erased. REVIVE searches through memory and finds the information that enables it to restore the pointers that have been changed . 03604. Apple II tape. $19 95 SLOW LIST/STOP LIST: Utility Programs for the Apple (Gilder) Start, stop, and controfthe speed of your program with Apple ll's game paddles. 03904, Apple II tape. $10.95 PSEUDODISK (Neuschatz) This money-saving pro- gram simulates a disk memory system for Integer BASIC programs. It allows multiple programs in memory at the same time which can be run from a catalog. 04804, APPLE II tape. $24.95 6502 DISASSEMBLER (Stamm) Produce assembly language source files with labeled subroutines and references from programs already in memory. It is compatible with Haydens ASSEMBLY LANGUAGE DEVELOPMENT SYSTEM. 08609. APPLE II Disk, $39.95 DATA MANAGER: A Data Base Management System and Mailing List (Lurus) Store information < a floppy disk, and retrieve it quickly and easily by specific names, or by category. 04909. Apple 11 Disk Version. $49 95 Apple is a trademark of Apple Computer Company, Inc.. and is nol affiliated with Hayden Book Company. Inc. F1NPLAN: A Financial Planning Program for Small Businesses (Montgomery) Allows you to enter data from a balance sheet into the program, to make as- sumptions about the future growth of business, and to have the computer project results for up to a five year period based on those assumptions. And if you change any data, the program revises all resulting data auto- matically. The disk version can be used only with TRSDOS Version 2.3. 05103. TRS-80 Level II tape, $69.95, 05108. TRS-80 Level II Disk Version. $74.95 SARGON II (Spracklen) The Champ of champs, "...an excellent program which will provide a true challenge for many players... Save your money and buy SARGON II..." '80 Software Critque. 03403. TRS-80 Level II; 03404. Apple II; 03410. OSI C1P-. 03440. OSI C4P. each tape $29.95. 03408. TRS-80 Level II Disk-. 03409. Apple I! Disk; 03414. OSI C1P Disk; 03444. OSI C4P Disk; 03484. C8P Disk; each $34.95 BLACKJACK MASTER: A S I mu la torfTu tor/Game (Wazaney) A serious game that performs complex simulations and evaluations of playing and betting strategies. 05303. TRS-80 Level II tape. $24.95. 05308, TRS-80 Disk Version. $29.95 REVERSAL (Spracklen) Winner of the software division of the First International Man-Machine OTHELLOTM Tournament, this version of the 200-year old game Reversi. features 27 levels of play and high -resolution color graphics. 07004. APPLE II tope. $29 95. 07009. APPLE II Disk. $34 95 ROYAL FLUSH: Competitive Poker Solitaire (Wazaney) A game you can play alone or with any number of players. High score wins in this poker-based, fun-filled card game. Choose from possible game variations. 07101. PET. 07103. TRS-80 Level II. each tape. $14.95 STARCLASH (Walton) An exciting game of galactic strategy for one or two players. 05903. TRS-80 Level 11 tape. $16.95 Available at your local computer store! Call Toll Free 24 hours a day, (1-800-821-3777, ext. 302)' TO CHARGE YOUR ORDER TO Master Card or Visa. Minimum order is $10.00; customer pays postage and handling. From Missouri call (1-800-892-7655. ext 302) 50 Essex Street, Rochelle Park, NJ 07662 Book Company, Inc. Circle 207 on inquiry card. BYTE April 1981 313 KILL SURGES LIKE LIGHTNING! AC power line surges are destructive, can cost you money, and can't be prevented. But you can stop them from reaching your sensitive electronic equip- ment with a Surge Sentry. Surge Sentry acts in picoseconds to dissipate up to a 1 ,000,000 W, lOOju, second surge. Triggers at 10% above nominal peak voltage. Works in parallel with the power line. Is easy to install for immediate protection. No complicated wiring or special tools required. Several different models to choose from, including an OEM version. Call or write today for a free brochure. iillltlili senbRV It'll clean up your AC JgJRKS ENTERPRISES, INC. 643 South 6th Street, San Jose, CA 95112 (408) 288-5565 DEALER INQUIRIES INVITED Technical Forum On the Use of Fourier Transforms to Explore Biological Rhythms A J Owens, Bartol Research Foundation, University of Delaware, Newark DE 19711 In his editorial "Is Pseudoscience Done by Computer Pseudo-Computer-Science?" (November 1979 BYTE, page 6), Carl Helmers encouraged the analysis of numerical data to test the validity of the biorhythm hypothesis: that our lives are dominated by a few quasi- sinusoidal cycles. He suggested taking data on our per- sonal lives, perhaps rating each day on a scale of 1 to 10, and then analyzing the time series using the fast Fourier transform (FFT). Coincidentally, motivated by some biorhythm pro- ponents in an introductory astronomy class that I was teaching, I have been carrying out exactly that program since January 1977. Through November 1979, my data set consisted of 1024 consecutive daily ratings of my per- sonal well-being, recorded by me each evening on a scale of 1 to 10. While reading Mr Helmers' editorial, I decided to pro- gram my AIM-65 microcomputer to analyze the data. (I had previously analyzed 256- and 512-day subsets of the data as they became available, using a FORTRAN pro- gram run on a minicomputer.) With only 4 K bytes of user memory, my AIM-65 could barely run the program to analyze 256 data points About the Author A ] Owens is a research physicist and professor at the Bartol Research Foundation of the Franklin Institute, which is located at the University of Delaware. He received his postgraduate degrees from the California Institute of Technology in the field of theoretical physics. Although he uses mainframe computers for his astrophysical research, he claims to be a novice in dealing with microcomputers, having graduated down- ward from time-sharing systems and minicomputers. He currently uses a Rockwell AIM-65 linked to a BETA-1 digital cassette system. Technical Forum is a feature intended as an interactive dialog on the technology of personal computing. The subject matter is open-ended, and the intent is to foster discussion and communication among readers of BYTE. We ask that all cor- respondents supply their full names and addresses to be printed with their commentaries. We also ask that correspondents supply their telephone numbers, which will not be printed. 314 April 1981 © BYTE Publications Irtc Circle 208 on inquiry card. Circle 209 on inquiry card. Circle 210 on inquiry card. 8" DISK CONTROLLER NOW- DOUBLE SIDED OPTION! • DOUBLES APPLE ][ STORAGE • APPLE DOS COMPATIBLE • SHUGART 800 OR 850 COMPATIBLE • IBM 3740 DATA ENTRY CAPABILITY • CP/M, UCSD PASCAL CAPABILITY Available at your local APPLE Dealer: $400. £SVA> SORRENTO VALLEY ASSOCIATES 11722 SORRENTO VALLEY RD. 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""System requires 48K contiguous RAM. Software is shipped on 8-inch floppy disks, and can be transferred to other formats. □ Check or money order enclosed □ Ship C.O.D. (U.S. orders only I Calif, and Mass. residents must add applicable sales tax. For foreign shipping charges, contact SofTech Microsystems. Ship to: Address: City: Zip: .State: .Phone: Allow six weeks for delivery. Wd mcnosvsTems n sussiDinnv of softech SofTech Microsystems, Inc. 9494 Black Mountain Road San Diego, CA 92126 Ph: 714/578-6105 TWX: 910-335-1594 (UCSD p-System and UCSD Pascal are trademarks of the Regents of the University of California. CP/M is a registered trademark of Digital Research Corporation. LSI-11 and PDP-11 are trademarks of Digital Equipment Corporation.) Technical Forum, — in fact, the comments had to be deleted to fit the pro- gram into the memory. The FFT algorithm used here was originally written for a Digital Equipment Corporation time-sharing computer, and the only modifications are the small input routine and the calculation of the power spectrum at the end. The fast Fourier transform routine for 256 data points takes about 3 minutes to run. It is of crucial importance in any time-series analysis to understand (and report) details concerning the statistical uncertainty in the results that are obtained. Otherwise, the importance of an insignificant wiggle in the Fourier transform at the "right" place can be blown far out of proportion. Fortunately, information scientists have studied the problem of extraction of signals from noise, and the basic concepts are not too difficult to grasp. For a complete (and technical) account, I suggest reading Ran- dom Data: Analysis and Measurement Procedures, by J S Bendat and A G Piersol (Wiley-Interscience, New York, 1971). Suppose that you begin with N data points, each a sample from some process that is random or noisy. Ob- viously, no matter how you "massage" the data, you have only N independent samples. In the fast Fourier transform, the N data points sampled at intervals of time separated by At are transformed into N Fourier coeffi- cients in the frequency domain, one each for the sine and the cosine terms corresponding to frequencies 1/NAf, 2/NAf, . . . , (N/2-1 )/NAf, l/2Af. For random data, the Fourier coefficients have random phases, so one usually reports the power spectrum, which is the sum of the squares of the sine and the cosine terms (altered by a multiplication constant used to normalize the result). The original N data points give N/2 power spectral estimates in frequency space, each with two degrees of freedom — one each from the sine and cosine terms. Inasmuch as each raw-power spectral-density estimate has only two degrees of freedom, it is rather poorly deter- mined. In only two-thirds of the cases can one expect the "true" power spectral level to be in the interval between zero and two times the measured power spectrum. To improve the accuracy of the estimates, one averages the power spectrum. One method of doing this, the one that I applied, is to divide the total data set into smaller groups of points, calculate the power spectrum for each subset, and then average the power spectra from each group. For example, my set of 1024 days was divided into four groups of 256 points each. Power spectra for each of the four groups were calculated, and the resulting four spectra were averaged at each of the 128 power spectral points in frequency space. A second approach is to calculate the power spectrum of the entire record (eg: 1024 days). One then averages the several adjacent frequency bins (eg: four) to get a smaller number of more accurately known power spec- tral estimates. In either case, averaging four spectra (or frequency bins), each with two degrees of freedom, gives power spectral estimates with eight degrees of freedom. As a result, we expect that, in two-thirds of the cases, the "true" power spectrum at a given frequency will then lie between 0.5 and 1.5 times the measured value. In general, the fractional uncertainty in each estimate is ±y/(2/D), 316 April 19B1 © BYTE Publications Inc Circle 211 on inquiry card. Circle 212 on inquiry card. Circle 213 on inquiry card. 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BYTE April 1981 317 SORCERER SOFTWARE from QUTILfry SOFTWTIRe All Programs Are On Cassette ARROWS AND ALLEYS™ arcade-like action at its best! The latest of Quality Software's great arcade games for the Sorcerer is ARROWS AND ALLEYS, by Vic Tolomei. You drive your car in a maze of alleys. Your task is to eliminate a gang of arrows that constantly pursues you. You have a gun and the arrows don't, but the arrows are smart and they try to stay out of your sights and will often attack from the side or from behind. Eliminate the arrows and another, faster gang comes after you. Four levels of play. Requires 16K or more of RAM. $17.95 BEDIT by Ernest Bergmann. A BASIC editor. This short and easy to use program is a machine language routine that loads in low memory and allows you to edit your BASIC programs by modifying text on the video screen. No more retyping a long line just to change one character. A few cursor movements make the necessary modifications. 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Interlaces with BASIC and the Word Processor Pac. $49.95 ********************************************* USE YOUR SORCERER FOR BUSINESS? Quality Software is currently preparing release of two cassette based business programs — a word processor at only $59.95 and a general business systems package at $99.95 that can be used for mailing lists, payroll, inventory, or accounts receivable. Both are written in machine language. Call us for details. ********************************************* We have more than 20 programs for the Sorcerer PLEASE WRITE FOR OUR CATALOG QUTiLrry softwtir6 6660 Reseda Blvd., Suite 105, Reseda, CA 91335 Telephone 24 hours, seven days a week: (213) 344-6599 HOW TO ORDER: If there is no SORCERER dealer near you, you may order directly Irom us. MasterCard and Visa cardholders may place orders by telephone. Or mail your order to the address above. California residents add 6% sales tax. Shipping Charges: Within North America orders must include $1.50 for first class shipping and handling. Outside North America the charge for airmail shipping and handling is $5.00 — payable in U.S. currency. •The name "SORCERER" has been trademarked by Exidy. Inc. Technical Forum. where D is the number of degrees of freedom. The BASIC computer program shown in listing 1 is quite simple. The routine in lines 100 thru 180 allows the data to be entered. Because the input data are real (ie: they have no imaginary component), they are stored in the one-dimensional array X, and the one-dimensional Listing 1: Power spectrum calculation program. This program was used to calculate the data points plotted in figures 1 and 2. 1 REM 2 REM 3 REM 6 REM PROGRAM FFTPOU POUER SPECTRUM USING FFT A. J. OWENS 16-N0V-79 REAL PART OF FUNCTION IN X> IMAG IN Y 10 DIM X<256> ,Y<256> 20 REM INPUT ROUTINE GIVES DATA X AND Y AND NUMBER OF DATA POINTS. Nr A POUER OF 2. INPUT ROUTINE IS IN LINES 100-199. FFT CALCULATION ROUTINE IS IN LINES 200-590. PRINTOUT OF THE POUER SPECTRUM IS IN LINES 591-800. INPUT ROUTINE 25 REM 27 REM 29 REM 30 REM 32 REM 34 REM 100 REM 150 N=256 160 FOR 1=1 TO N 170 INPUT X=0 180 NEXT I 200 REM BEGIN FFT CALCULATION 202 G=INT/L0G<2)-rl.00000E-06> 203 P=2*3.14159/N 204 FOR L = TO G-l 206 G1=2"(G-L-1) 20(3 M=0 210 FOR 1=1 TO 2"L 220 K1=INT(M/G1 ) 230 GOSUB 530 240 Y1=C0S(P*K2> 250 Y2=-SIN(P*K2> 260 FOR J=l TO Gl 270 Y3=X*Y1-Y=X(M+1)-Y3 300 Y=I THEN 480 420 K3=X 430 X 460 Y( IH )=Y(K2+1) 470 Y(K'2+1)=K3 480 NEXT I 499 GO TO 591 500 REM STATEMENTS 500 TO 510 PRINT OUT RESULTS 501 REM OF THE FFT ITSELF; SKIPPED HERE 502 FOR 1=0 TO N-l 504 PRINT i;X(I+l>; '+I'»Y(I+1> S06 NEXT I 520 GO TO 591 530 K2=0 540 FOR K=l TO G 550 K3=INT(Kl/2) 560 K2=2* 670 NEXT I 680 F=(2*J+M)/(2*N*T> 690 PRINT F.S 700 NEXT J 800 GO TO 599 999 END 318 April 1981 © BYTE Publications Inc Circle 215 on inquiry card. Circle 216 on inquiry card. 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BOX 1628 CHAMPAIGN, IL 61820 (217)359-2112 Technical Hot Line: (217) 359-2691 (answered only when technician is available) SuperSoft First in Software Technology TRS-80 TRADEMARK TANDY CORP Technical Forum. < 5 o Q- 10 1 1 1 1 1 1 1 5 - \ / \ A A f\ A 2 \ / A V t \ / \ \l t \/ 2 0-40 DAYS 7 DAYS 0.5 1 i i i i i i 10 20 FREQUENCY IN (256 DAYS! 30 -1 40 Figure 1: A power spectrum chart averaging four periods of 256 days each. This figure of the low end of the full-power spectrum graph shows the relative intensities of sine waves of various fre- quencies. The range of values bracketed by the arrows labeled "20-40 days" represents the power of sine waves with periods between 20 and 40 days. If biorhythms were present in this power spectrum, they would have appeared as significant peaks at certain points within this range. The vertical line at fre- quency = 15 shows the possible variation of the point on the graph and is a measure of the possible error in measurement at that point. 10 < Q et iu 2 o Q- 1 " 1 1 t l i ^\t • - f-0.5^^ # "T • >^ • • • _ • _ > t , ••* • • . 20-40 DAYS 7 DAYS i i i i • 0.05 0.1 f (DAY -1 ) 0.2 0.5 Figure 2: A modified power spectrum chart. The data of figure 1 was averaged over four frequency bins, giving a more accurate set of data points, and plotted using logarithmic scales for both the frequency and power axes. The notation used is described in the caption for figure 1. array Y is set to zeros. Lines 200 thru 590 perform an N-point fast Fourier transform: F„= E Z k exp (—2-jrikn/N) where Z k = X k + iY k is the (complex) input vector and F„ is the complex Fourier transform (i = ^J — 1 and is the unit measure along the imaginary axis when dealing with complex numbers). The real (cosine) part of F is placed in X and the imaginary (sine) part in Y by the routine. The nth frequency, corresponding to the Fourier coefficient F„, is /„ = n/(NAt). The power spectrum is calculated in 320 April 1981 © BYTE Publications lnc Circle 220 on inquiry card. PHiooqrq Modem Kit 300 Baud Acoustic Coupler $69.00 Includes: Power Supply Speakers Printed Circuit Board All Integrated Circuits, Resistors & Capacitors Instruction and Trouble Shooting Book Order Direct or Call for the Location of the Closest Dealer Add $4.00 for Shipping Charge. Ohio Residents add 6.5% for Sales Tax I f* MASTERCHARGE oho oqrs products coqpORsrnon 14600 Detroit Avenue • Cleveland. Ohio 44107 • (216) 221-9000 Allow 6 weeks lor Delivery I I I Circle 221 on inquiry card. SPEED UP YOUR SYSTEM! Fortran or Compiled Basic 3 times faster using the Memtech Arithmetic Processing Unit Interface. '£**W This interface enables any S-100 buss microcomputer to communicate with the AMD 951 1 APU. It can perform a Floating Point Multiply in 56 M S vs. 3000 /xS in soft- ware. 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Low density color graphics of 128 x 192 are also available in einht colors. iii-ju resolution - black and white qraphics text and TRS-80™ standard graphics. Reverse video, composite video RF output, PERFORMANCE The LNWao utilizes the fast Z-8QA microprocessor which executes at a speed of 4 MHZ - over twice the speed n\' the TRS-80™ Model I. of 384 x 192 mixed with PC BOARD $89.95 LNW RESEARO Ask about our : Keyboard N EXTERNAL DATA SEPERATOR caDlnet L««d«i VIMO 100 -BO 1 W LNW RESEARCH 14661 ■ C MYFORO RD TUSTIN CA 92680(714)552-8946 ORDERING INFORMATION VISA SYSTEM EXPANSION AT A^O" | PC BOARD A ] 9Q7 LUSER MANUAL J • SERIAL RS232C 20mA I/O - FLOPPY CONTROLLER • 32K BYTES MEMORY • PARALLEL PRINTER PORT • DUAL CASSETTE PORT > REAL-TIME CLOCK • SCREEN PRINTER BUS ONBOARD POWER SUPPLY SOFTWARE COMPATIBLE SOLDER MASK, SILK SCREEN Circle 222 on inquiry card. BYTE April 1981 321 6809 SOFTWARE im BY MICROWARE c " OS-9™ MULTIPROGRAMMING OPERATING SYSTEM /m true multitasking, real time operating system for / % timesharing, software development, database, A m process control, and other general applications. This versatile OS runs on almost any 6809-based computer. ■ UNIX'" -like file system with hierarchical directories, byte-addressable random-access files, and full file security. Versatile, easy-to-use input/output system is hardware in- dependent and expandable. ■ Powerful "shell" command interpreter features: I/O redirection, multiple job stream processing, and more. In- cludes a complete set of utility commands. ■ OS-9 Level Two uses hardware memory management and can address over one megabyte of memory. Also includes pipes and filters for inter-process data transfers. ■ OS-9 Level One runs on systems without memory management hardware having up to 56K memory. DOS-9 Level Two $495* □ Level One $195 BASIC09™ PROGRAMMING L ANGUAGE SYSTEM Extended BASIC language compiler/interpreter with integrated text editor and debug package. Runs standard BASIC programs or minimally-modified PASCAL programs. ■ Permits multiple named program modules having local variables and identifiers. Modules are reentrant, position independent and ROMable. ■ Additional control statements for structured programming: IF . . . THEN . . . ELSE, FOR . . . NEXT, REPEAT . . . UNTIL, WHILE ... DO, LOOP . . . ENDLOOP, EX/TIF . . . ENDEXIT. ■ Allows user-defined data types and complex data structures. Five built-in data types: byte, integer, 9 digit floating-point, string and boolean. ■ Runs under OS-9'" Level One or Level Two. D$195* OTHER OS-9" FAMILY SOFTWARE ■ Stylograph™ Screen-Oriented Word Processor ■ Interactive Assembler ■ Macro Text Editor ■ Interactive Debugger BAS1C09 and OS-9 are trademarks of Microware" and Motorola. UNIX is a trademark of Bel! Laboratories.* Most software is available on ROM or diskette in versions for many popular 6809 computers. Contact Microware® for specific availability. ^m MICROWARG* Microware Systems Corp., Dept. B2 _==- 5835 Grand Avenue, Des Moines, Iowa 50304 gg. (515) 279-8844 • TWX 910-520-2535 Technical Forum. Frequency in (256 days) -1 log,,, (Power) 1 1.00 2 1.20 3 0.83 4 0.59 5 0.10 6 0.76 7 0.94 8 0.91 9 0.61 10 1.00 11 0.29 12 0.79 13 0.65 14 0.16 15 0.13 16 0.79 17 0.62 18 0.44 19 0.26 20 0.56 21 0.39 22 0.73 23 0.52 24 0.12 25 0.17 26 0.58 27 0.08 28 0.62 29 0.53 30 0.42 31 0.72 32 0.47 33 0.74 34 0.57 35 0.27 36 0.70 37 0.48 38 0.49 39 0.12 40 0.49 Table 1: Table of values for the power spectrum chart of figure 1. The second column of numbers is the base-10 logarithm of the value of the power. For example, for point 20, 10° ■" equals 3.63 which is the value plotted in figure 1 at the point frequency = --20. The marks for 7, 20, and 40 days in figure 1 correspond to frequency values (with units of (256 days)") of 36.6, 12.8 and 6.4, respectively. The logarithm of the variation of the error mark at frequency = 16 is +0.18 and —0.30 from the recordec value of 0. 79. lines 591 thru 800, using the relation: P„ = (2Af/N)|F„| 2 The program allows averaging of the power over any specified number of frequency bins. If M frequency estimates are averaged, the number of degrees of freedom in the single power spectrum is D = 2M and the frac- tional statistical uncertainty is ±V(2/2M) = ±V(1/M). As mentioned above, I scored 1024 consecutive days on a scale of 1 to 10 and analyzed the data in 256-day groups. The average scores for the four groups were 5.1, 4.6, 4.5, and 4.6, indicating a mean near 5 with a hint of a long-term decline. The day-to-day variation (standard deviation) was close to 1 for each of the four periods. Averaging the power spectra for the four periods, I ob- 322 April 1981 © BYTE Publications Inc Circle 223 on Inquiry card. Circle 224 on inquiry card. [ NEW! CHfcCKBOOK CHECKWRITER PROGRAM FOR: TRS 80CC '■' TRS 80 LEVEL II" 1 ATARI 8O0' M APPLE ll IM HEATH H-89' v CASSETTE TAPE S9.95 or LISTING 55.95 5» Circle 225 on inquiry card. S IMOW. . .Continuous Checks That Can be Used With or Without Your Computer!/ The Best in A Home Checking System That's right Continuous Checks fan-folded in a 3- to -a -page desk set design And they can be computer primed, handwritten or typewritten — whichever suits the quantity or situation. SPECIAL DESIGN Our checks are not a high-volume business form adaptation. They're specially designed Computer/Manual Checks for the home or low volume user. And Programming is Easy. All stub and check information is un the same line No need to change tractor width when loading either Our checks are the same QW width as standard tractor feed printer paper Tear down 8U8 is the same as the classic personal sued check issued by all banks. COMPLETE HOME SYSTEM With this system you can print the bulk of your monthly checks on your computer. Your checks and slubs can then be stored in our attractive Data Ring Binder Checkbook. Later, if you have a tew checks to write, there's no need lo load them into a printer - just write a check at your desk as shown above. And you can mail your checks in our dual win- dowed envelopes to eliminate addressing ChOreS. 1R&HU- l.nU,, l,x M.iiBOO -SlAMH ine. Appl.ll '» UNIQUE You won't find checks like these anywhere. And. our special small quantity printing pro- cess will give you excellent quality and appear- ance. Standard color -coordinated imprinting and encoding is as shown above (logo can be omitted) on blue, grey, tan, or green checks. PRICED RIGHT Two Hundred checks are just $29.95 {enve- lopes S13.95). Five Hundred checks are S49.95 (envelopes S27.95) Data Ring Check- books are only S6.95. Special "ORDER NOW" Offer If you order directly from this ad. we'll send you a monthly Checkbook-Checkwnting program FREE on cassette tape for any one of the computers listed above. You'll save 59.95. Just enclose a voided check (for encoding information) with your payment (VISA - MasterCard orders must show signature. expiration date, and account number). Or. send today for samples. Sorry, we can't make [his Free Offer unless you order directly from our SYNERGETIC 4715 shepherd rd. SOLUTIONS MULBER ?I 86 F n- PHONE- (6131 646-6557 JJOOU Complete AIM 65 Expansion For complete AIM 65 expansion, Fore- thought Products brings you the AIM- Mate Series, quality expansion products with price, performance and versa tility that puts them in a class of their own. AIM-Mate Series expansion, including RAM (to 48K), PROM, I/O, video and floppy disk interface, STD BUS interface, parity protection and more, lets you con- figure the kind of system you need. The compact AIM-Mate case puts it all together in a sturdy, portable, desk top unit. Write today for complete details on the AIM-Mate System- AIM 65 expansion products for the professional. jFORETHOUGHT l^SPRODUCTS 87070 Dukhobar Road, Eugene, Oregon 97402 (503) 485-8575 The DataTrak" 5 Floppy Disk Drive The DataTrak" 8 Floppy Disk Drive from Qlime. Distributed by asap The DataTrak 5 double-sided double-density drive uses state-of-the- art technology to give you superior data integrity through improved disk life, data reliability, and drive service- ability using S l A M media. Quine's independent head load yields wear characteristics far superior to competitive drives. This superior wear performance produces savings on both diskette usage and drive maintenance. Improved data reliability, resulting from superior amplitude and bit shift characteristics, optimizes operator effi- ciency and reduces processing time for end-users. And Data Irak's unique modular design means simplified field servicing for you and your customers. Design Features Expanded storage capacity •Two-sided, double density Proven head carriage assembly •Ceramic head with tunnel erase •Dual-head flex mounting arrangement •Superior head bdd dynamics Precise lead screw actuator •past access time - 20 ins irack-lo-track •Low Iriclion and minimum wear •Low power dissipation Additional features •Industry standard 5V4" media format •ISO standard write protect •Door lock out (or media protection •Requires DC voltage only •Daisy Chain up to 4 drives •Heads load oil command independent of loading media Product Specifications Performance Specifications Capacity Unformatted: 437. 5K or 50UK bytes Qume Formatted: 286 7 K or 327. 7K bytes Recording Density: 545b BPi Track Density 48 I'PI Cylinders: 35 or 40 Tracks' 70 or 80 Recording Method: FM or MFM Rotational Speed: 300 RPM Transfer Rate: 250K bits/second Latency (avg .): 100 ins Access Time: Track-to track 20 ms Settling 15 ms Head Load Time: 50 ms The DataTrak™ 8 double-sided, double-density drive uses state-of-the-art technology to give you superior data in- tegrity through-improved disk life, data reliability, and drive serviceability. Qume's innovative approach to con- trolling head load dynamics yields wear characteristics far superior to competi- tive drives. In independent evaluation. DataTrak 8 is setting industry stand- ards for tap test performance. This superior wear performance produces savings on both diskette usage and drive maintenance. Improved data reliability, resulting from superior amplitude and bit shift characteristics, optimizes operator effi- ciency and reduces processing time for end-users. And DataTrak's unique modular design means simplified field servicing for you and your customers. Design Features Expanded storage capacity •Two sided, double density Fully IBM compatible •IBM 3740 and System 32 drives •IBM 3600 and 4964 drives • IBM Sytem 34 drives Proven head carriage assembly •Ceramic head with tunnel erase •Dual-head flex mounting arrangement •Superior head load dynamics Fast, precise steel belt drive • Fast access time -3 ms track-to-track •Low friction and minimum wear • Low power dissipation Additional features •ISO standard wrile protect •Programmable door lock •Negative DC voltage not required •Daisy Chain up to 4 drives •Side-by-side mounting in standard 19" RETMA rack Product Specifications Performance Specifications Capacity Unformatted l.b Mbytes/disk IBM formal 1 2 Mbytes/disk Recording Density 6816 BPI Track Density. 48 TP1 Cylinders 77: Tracks. 154 Recording Metliod: MFM Rotational Speed- 360 RPM Transfer Rate: 500K bits/second Latency (avg.): 83 ms Access Time: Track-to-track 3 ms Settling 15 ms Average 91 ms Head Load Time: 35 ms Disk: Diskette 2D or equivalent computer 3S3p products, inc. 1198 E. Willow Signal Hill, CA 90806 AUTHORIZED DISTRIBUTOR FOR QUME CALL FOR PRICE AND DELIVERY (800) 421-7701 Or (213) 595-6431 (In California) Circle 226 on inquiry card. BYTE April 1981 323 HELPING THE SMALL COMPUTER ENTREPRENEUR How To books and seminars from Essex Publishing Company SYSTEM 5 HOUSE #10. HOW TO START YOUR OWN SYSTEMS HOUSE. Leslie Nelson. Practical step-by-step guide for the HDP professional or small business- man. Covers all aspects of starting and operating a small systems busi- ness. $36.00 #35. SOKTWARE WRITER'S MARKET. Bernard Korites. 1800 places tosellyoursoftware. Ifyou are in the suit ware business this directory is your key to profits. $45.00 #130. HOW TO START & OPER- ATE A MAIL-ORDER BUSINESS. Julian Si/nan. Indispensible for those selling software, equipment or sup- plies by mail. 3rd revised edition. 544 pages. $24.95 #290. HOW TO FINANCE YOUR SMALL BUSINESS WITH GOV- ERNMENT MONEY. R.S. Hayes and J.C. Howell. Amazingly, one of the best sources of start-up and ex- pansion capital is Uncle Sam. This book shows you in detail how to go about it. $14.95 #21 1. HO W TO START AND PRO- MOTE YOUR OWN NEWSLET- TER. Howard L Shenson. Newslet- tering is a high profit business. This detailed, step-by-step seminar shows you how you can do it. Includes cas- settes, written materials and binder $59.00 #291. HOW TO SUCCEED IN YOUR OWN BUSINESS. W.R. Park and S.C. Park. Gives the first-time, untested entrepreneur a look at what to expect. Brings a wealth of specific operating data for over KO kinds of businesses. $19.95 ESSEX PUBLISHING CO. 285 Bloomfield Avenue • Caldwell. N.J. 07006 Ordei Hooks bv number; i i Send cheek, money order (US S). VISA or Master Charge fl. Publisher pavs4lh class shipping. I For UI'S shipping (U.S. A. only) add S 1 .00 per book. For Air Mail shipping add $2.50 per book ' in the U.S.A.. S6.00 in Mexico and Central America. SI 2. 00 per book elsewhere. N.J. residents I add 5'r sales rax. D Cheek enclosed D Credit Card □ 4th Clas a lips □ Air Name Address City SI Card U 1 for faster shipment on credit card orders call (201) 783-6940 between 9 and 5 Eastern time. Zip Exp, Date- Technical Forum, Point Number log 10 (f) log 10 (Power) 1 -2.01 0.96 2 -1.60 0.78 3 -1.39 0.75 4 -1.25 0.53 5 -1.14 0.49 6 -1.06 0.50 7 -0.99 0.43 8 -0.92 0.55 9 -0.87 0.61 10 -0.82 0.42 11 -0.78 0.39 12 -0.74 0.45 13 -0.70 0.24 14 -0.67 0.22 15 -0.64 0.45 16 -0.61 0.26 17 -0.59 0.24 18 -0.56 0.24 19 -0.54 0.11 20 -0.51 -0.07 21 -0.49 0.30 22 -0.47 0.06 Table 2: Table of values for modified power spectrum of figure 2. Here, both columns of numbers are the base-10 logarithms of their respective values as plotted in figure 2. For example, for point 2, lCr' M and Iff 3 * give values of 0.025 and 6.026, which can be read off the horizontal and vertical axes of figure 2. The marks for 7 20 and 40 days in figure 2 correspond to frequency values (with units of (days)-') of 0.141, 0.050, and 0.025, respectively. The logarithrr of the variation of the error ma rk as shown in figure 2 is +0.10 and -0.12. tained the power spectrum, the low-frequency part of which is shown in figure 1. Note that the power spectrum's vertical axis is logarithmic; this makes the size of the statistical uncertainty in each point the same. A typical error flag at frequency = 15 is shown. A few rele- vant cyclic periods are shown, including the week (seven days) and the canonical biorhythm periods (twenty to forty days). The safest thing to say is that there is no evidence whatsoever for enhancements above the background noise level in the biorhythm range. Even if all the varia- tion in the six power spectral points in the twenty- to forty-day range is attributed to biorhythms, the contribu- tion is only about fifteen percent of my total variance from day to day. But there is no evidence for any periodicities in this region, and the noise in the biorhythm range looks similar to that at both lower and higher frequencies. The perceptive reader may notice that the power spec- trum shown in figure 1 is not flat, as would be the case for perfectly "white" or uncorrelated noise. This implies that there is some temporal structure in my day-to-day feeling of well-being. To investigate this more closely, I averaged the data in figure 1 over four adjacent frequency bins, to give power spectra with thirty-two degrees of freedom. The results are shown in figure 2, given as a log-log plot. The solid line shows that the power spectrum is well fit by a power law spectrum, P(f) oc f-° s . This is an unusual power spectrum. White noise has a flat spectrum, and random-walk noise has a f' 2 spectrum. Electrical "flicker 324 April 1981 © BYTE Publications Inc Circle 227 on inquiry card. Circle 228 on inquiry card. Circle 229 on Inquiry card. New Low-cost Modem MA-50 • Answer/Originate • 300 Baud • Bell 103 and 113 Compatible • RS232C Interface • Half/Full Duplex • Full One Year Warranty Complete with manual and AC safety transformer. $11900 Add $2.00 shipping VISA M.C. accepted ODDetaresearch, Inc. 1100 SE Woodward Portland, Oregon 97202 (503) 232-1712 JDR MICRODEVICES, INC. 1101 South Winchester Blvd. San Jose, California 95128 800-538-5000 408-247-4852 NEED YOUR ORDER SHIPPED TODAY? THEN CALL TOLL FREE 800-538-5000 Include S2.00 for shipping. $10.00 minimum order. send SASE for complete catalog. Bay Area Residents add 6'/2%sates tax. Calif. Residents add 6% sales tax. Your .^■Bfe. .^Mfet [master charge!! BankAmericard -_- -__ _ WE WILL BEAT ANY COMPETITORS PRICES. GRTC US A CALL AND WE'LL PROVE IT!!! LS SERIES LOOK AT THIS LS PRICING! 74LS00 .32 74LS38 .39 74LS122 .55 74LS1701.89 74LS266 .68 74LS01 .28 74LS40 .25 74LS123 .99 74LS173 .82 74LS273 1.69 74LS02 .38 74LS42 .79 74LS125 .99 74LS174 1.19 74LS275 3.39 74LS03 .32 74LS47 .78 74LS126 .88 74LS175 1.09 74LS279 .59 74LS04 .35 74LS48 .78 74LS132 .69 74LS1812.19 74LS2B3 1.03 74LS05 .28 74LS51 .35 74LS136 .58 74LS190 1.15 74LS290 1.25 74LS08 .38 74LS54 .35 74LS138 .79 74LS191 1.31 74LS293 1.89 74LS09 .38 74LS55 .32 74LS139 .79 74LS192 .8B 74LS295 1.09 74LS10 .32 74LS73 .44 74LS145 1.19 74LS193 .98 74LS298 1.24 74LS11 .29 74LS74 .48 74LS148 1.39 74LS194 1.80 74LS352 1.59 74LS12 .29 74LS75 .58 74LS151 .79 74LS195 1.39 74LS353 1.59 74LS13 .38 74LS76 .50 74LS153 .79 74LS196 .82 74LS363 1.39 74LS14 .99 74LS78 .59 74LS154 2.39 74LS197 .82 74LS365 .99 74LS15 .35 74LSB3 .90 74LS155 1.19 74LS221 1.28 74LS366 .99 74LS20 .26 74LSB5 1.23 74LS156 .95 74LS240 1.-89 74LS367 .99 74LS21 .30 74LSB6 .45 74LS157 .79 74LS241 1.89 74LS36B .99 74LS22 .34 74LS90 .70 74LS158 .82 74LS242 1.89 74LS373 1.85 74LS26 .40 74LS92 .82 74LS160 .94 74LS243 1.89 74LS374 1.81 74LS27 .35 74LS93 .71 74LS161 .99 74LS244 1.79 74LS377 1.48 74LS28 .39 74LS95 1.11 74LS162 .99 74LS245 2.89 74LS3B5 1.90 74LS30 .35 74LS96 .86 74LS163 .99 74LS251 1.32 74LS3B6 .65 74LS32 .39 74LS107 .43 74LS164 .99 74LS253 .89 74LS390 1.90 74LS33 .54 74LS109 .49 74LS165 .99 74LS257 .89 74LS393 1.90 74LS37 .78 74LS112 .48 74LS166 2.40 74LS258 .89 74LS395 1.69 74LS113 .48 74LS168 1.79 74LS259 2.89 74LS670 2.20 74LS114 .55 74LS1B9 1.79 74LS260 .68 MEMORY SALE 4116— 300NS 4116— 200NS 2114L— 300NS 2708— 450NS 2716— 5V 450NS 2732— INTEL 2532— Tl PIN OUT 8/19.95 8/23.95 8729.95 4.95ea 7.95ea 29.95ea 21.95ea 100/2.25ea 100/2.75ea 100/3.00ea 8/4.80ea 8/6.95ea CALL CALL THESE PRICES GOOD FOR BYTE READERS ONLY— TO GET THESE UNHEARD OF PRICES YOU MUST STATE WHEN ORDERING:APRIL BYTE MEMORY SALE— SALE ENDS APRIL 30, 1981 3242 REFRESH CHIP FOR 16K RAM $9.95ea 8080A Z80 8085A 12.95 80B0A 3.95 8212 2.75 8214 5.25 821 6 2.75 8224 2.95 8226 3.49 8228 4.95 8238 8251 8253 8255 8257 8259 8275 8279 5.50 6.95 12.95 6.50 16.95 14.95 49.95 15.95 Z80-CPU 8.45 Z80A-CPU 9.45 Z80-DMA 18.00 Z80SIO/2 27.50 Z80-SIO/9 20.50 Z80-CTC 7.65 Z80-PIO 7.60 ALL MERCHANDISE 100% GUARANTEED! CALL US FOR VOLUME QUOTES Circle 230 on inquiry card. BYTE April 1981 325 COMPUTER FORMS KIT with continuous business forms for small computer systems Each kit contains samples, programming guides, flyers, prices and order forms for checks, invoices, statements, envelopes, stock paper and labels to fit almost every computer system. • Available in quantities of 500, 1,000, 2,000 4,000, 6,000 • Low Prices (500 checks only $32.50) DNVODCI £M, iu.<^»_ • FAST SERVICE — It is our policy to ship within 6 working days following our receipt of your order. • MONEY BACK GUARANTEE — If for any reason you are not completely satisfied, your money will be promptly refunded. Fast Service by mail or. . .PHONE TOLL FREE 1 + 800-225-9550 Mass. residents 1+800-922-8560 8:30 a.m. to 5:00 p.m. Eastern Time Monday — Friday Technical Forum, Please Ship FREE Kit To: Name CODE 460 Company Street City, State and Zip Phone Computer make & model ■ Computer Forms -J 78 HollisStreet, Groton.Mass. 01450 A division of New England Business Service, Inc. noise" has an /" 1 spectrum. My biorhythms, instead of producing quasi-periodic "music of the spheres," seem to be more in the nature of a slightly colored and unique random hisslB Biorhythms and Fourier Transforms Proponents assert that the relative strength and weakness of mankind in areas roughly described as "physical," "emotional," and "intellectual" vary in cycles of twenty-three, twenty-eight, and thirty-three days, respectively, with each of the curves approx- imating sine waves of equal amplitude. Of course, the effects of each influence are added together, so that an overall index of a particular day's merit (as the author recorded by assigning each day a number between 1 and 10) would not readily show the presence (or absence) of these sinusoidal waves. This is where Fourier transforms (either fast or discrete) come in. In theory, any complex periodic waveform can be shown to be the sum of a number of sine waves of differing frequencies and amplitudes. The Fourier method transforms an amplitude-versus- time waveform into its equivalent amplitude-versus- frequency waveform — ie: the transformed waveform tells the relative strengths of the different frequency sine waves that, when added together, will give the original amplitude-versus-time waveform. Once this is understood, it becomes apparent that, if a specified waveform contains definite twenty-three-, twenty-eight-, and thirty-three-day cycles, these cycles should cause visible peaks in the appropriate places on the frequency (horizontal) axis of the transformed waveform. The lack of such peaks would indicate that these frequencies contribute no more to the overall waveform than other frequencies do. A transformed wave that is roughly a flat horizontal line indicates that sine waves of all frequencies contribute equally to the original waveform. Such a waveform has no domi- nant frequencies. A signal consisting of random com- ponents with no discernible dominant frequencies is known as white noise. Another verification of the transformed wave is concerned with the amplitude of existing peaks. In this situation, those peaks that correspond to the biorhythm cycles should be of equal amplitude, because the three biorhythm cycles are defined as be- ing of equal amplitude. Response by Carl Helmers This article suggests an approach to verification of any biological cycles hypothesis. It is not a controlled scien- tific experiment, and any conclusions are thus applicable only to this particular individual's characteristics. By applying techniques of signal analysis to a broader population of individuals, it might be possible to design a scientifically valid experiment. References Bendat, J S, and A G Piersol, Random Data: Analysis and Measure- ment Procedures, Wiley-lnterscience, New York NY, 1971. Stanley, W D, and S J Peterson, "Fast Fourier Transforms on Your Home Computer," December 1978 BYTE, pages 14 thru 25. 326 April 1981 © BYTE Publications Inc Circle 231 on Inquiry card. Circle 233 on inquiry card. ^*=ksofiww TM The Key Sequential Access Method (ISAM) for the professional. In many successful applications since 1977. Used by equipment manufacturers like Cromemco & Philips. 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R A NSlyE T CORPORATION 1945 ROUTE 22 • UNION, N.J. 07083 • (201) 688-7800 TWX 710-985-5485 si CALL IN YOUR ORDER NOW! (617)373-1599 ZENITH • ALTOS • TRS 80 Circle 234 on inquiry card. "We're doing to SOFTWARE what 'MICRO' did for the computer." SPECIALISTS svsTEms, inc LMtJ,LI1 "-■' " ,i - J FULL SERVICE P.O. Box 1 225,2 Washington Street,Haverhill, Ma. 01 830 SYSTEMS Ask BYTE Conducted by Steve Ciarcia 4116 Pointers Dear Steve, Being an ardent do-it-your- selfer, I'm currently in the process of designing a home- brew computer system. Since the 16 K-bit type-4116 dy- namic memories are cheap, compact, and use little power, I have decided to use them as my main memory components. Designing the interface is no problem, but I'm all too aware of the 4116's cantankerous nature with re- spect to circuit-board layout, power-supply fluctuations, and so forth. What should I know about these devices? Ken McDonald Yellowknife, NWT, Canada The most important thing to remember when designing any computer that uses 4116s is that the power-supply volt- ages have to be turned on and off in sequence. To keep from blowing the 4116 on power- up, the —5 V supply must be turned on before the +5 V and +12 V supplies. On power-down, the — 5 V has to remain on while the + 5 and +12 are removed. In lower-current power supplies (such as you will probably use), the sequenc- ing can be accomplished through the time constants of the power supply itself; this technique is used in the TRS-80. By giving the -5 V section a very fast time con- stant compared to the other two supplies, it appears to come on first. On power- down, the sequence is re- versed. Because the —5 V has such a low-current draw on it, it will stay up long after the other voltages have dropped. Other than that, use prime components and stay away from surplus devices. For more information on refresh timing signals of dynamic memories, refer to my article in the March 1981 BYTE "Build the Disk-80: Memory Expansion and Floppy-Disk Control, " on page 36. . . .Steve Any Port In a Storm Dear Steve, I'm not sure if I understood the little that I read of your article "I/O Expansion for the TRS-80, Part 2: Serial Ports." (See the June 1980 BYTE, page 42.) Can I use the modem on my Radio Shack RS-232C port and my serial (Diablo) printer on your RS- 232C port or vice versa? If so, are there any tricks to it7 Stan via The Source You say that you already have an RS-232C interface, so I'll presume it is Radio Shack's TRS232, which is in- stalled inside the TRS-80 Ex- pansion Interface. Normally, only one interface can be ac- commodated, and it is hard- wire-addressed as port hexa- decimal E8. Because the COMM-80 has selectable ad- dressing, it can be added to your system and set for one of fifteen other addresses. With a software driver that directs any output to this sec- ond serial port, you can plug your Diablo into it and use both ports without conflict. What you really need is a CHATTERBOX, which is a COMM-80 with an acoustic modem installed in the same enclosure. It is designed so that, when the modem is in use, the characters being transmitted and received are ~ymr^^ Anti-Static a ^r-^ Dust Comers Protect your computer and accessories. • Anti-static vinyl helps prevent static from damaging sensitive components and caus- ing faulty operation. • Double-fold stitching will not rip out and is unmatched for strength and long life. • Heavy gauge textured vinyl blends with any decor and folds easily for convenient storage. • Over 1000 custom designs gua- ranteed to fit precisely. • 100% satisfaction guarantee means we stand behind our product. Yes, there are differences in Dust Covers. Differences which can be vitally important to the proper functioning of your system. At Cover Craft we've manufactured the highest quality Dust Covers for the electronics industry for more than six years. We've been selected by major equipment manufacturers to make covers for their products. Our covers are in use in every state and in more than 50 countries. We know what it takes! THE BEST DUST COVERS AT AMY PRICE MOST PRICED $7.95 to $11.95 PLUS POSTAGE AMD HANDLING VISA-MasterCharge So visit your dealer or contact Cover Craft for our latest catalog and list of over 200 dealers. C COVER CRAFT P.O. BOX 555 'AMHERST, NH 03031 • (60 (603)889-6811 328 April 1981 © BYTE Publications Inc Circle 235 on Inquiry card. sent out through the RS-232C connector. You can plug your Diablo directly into the CHATTERBOX and have a modem with a printer out- put. Absolutely no changes in any software are needed. ...Steve TRS-80 Tape Formats Dear Steve, The TRS-80 has more soft- ware created for it than any other system. This software is usually transferred on a cas- sette that is readable only on Table 1 Tape Formats BASIC Tape Format Leader 256 zeros followed by an A5 sync byte D3 D3 D3 BASIC header XX Single-character file name LOB (low-orde r byte) Next line's address HOB (high-order byte) Pointer LOB Line number HOB XX ... XX Line contents 00 End-of-line marker 00 00 End-of-file markers System Tape Format Leader 256 zeros followed by an A5 sync byte 55 System-format header byte XX XX XX XX XX XX 6-character file name 3C Data header XX Data length, 00 = 256 bytes LOB Loading HOB Address XX ... X> Actual line contents XX Checksum of line bytes and load address 78 End-of-file marker LOB Entry HOB Address Editor/Assembler Source Tape Format Leader 256 zeros followed by an A5 sync byte D3 Source header XX XX XX XX XX XX File name d1 d2 d3 d4 d5 5-digit line number in ASCII (bit 7 is set) 20 Data header XX ... XX Line (128 bytes maximum) 0D End-of-line marker 1A End-of-file marker BASIC Statement Storage Format in Memory LOB Address of HOB next line LOB Line number in HOB binary form XX ... XX Line contents 00 End-of-line marker 00 00 End-of-file marker E.R. Hardin's miLITARY mflDflESS for Apple, Atari and TRS-80 TOMCAT vs. MIG Blue skies and 40,000 feet over the Rhine Valley, when a MIG-25 suddenly blips onto your radar screen. Your F-14 Tomcat has a brace of rockets and avionics to help survive the antics of Ivan. Are you brave enough to climb into the cockpit and take your chances against a Russian pilot? cassette $19.95 GUNSHIP Datel me; Vietnam. Tet offensive of 1968. Battle g round troops with mini- guns and rockets. Crash and burn if you're c umsy. cassette $19.95 GREEN BERET Run a mission behind the lines, in North Vietnam. Blow up bridges, kidnap politicos, raid prison camps. You are the team commander. cassette $19.95 511 Iowa Ave. Iowa City, IA 52240 y///////////////;////////^^^ Call 1-800-227-1617, operator 364 (in California800-772-3545,operator 364) MASTERCHARGE Circle 236 on Inquiry card. April 1981 © BYTE Publications Inc 329 Ask BYTE a TRS-80. For people with other computers, this vast amount of software is un- usable. Please tell me the data-storage format used by Tandy for its TRS-80. Paul Shields Victor Harbor, S A, Australia Table 1 on page 329 shows the various TRS-80 Model I cassette-recording for- mats.... Steve Problem With Light Controls Dear Steve, It seems that a lot of BYTE readers are interested in home control via the BSR System X-10. I've fooled around with computerized home-control devices for some time, and I think BYTE readers should be aware of one rather distress- ing trait of the light-control modules. When an incandescent bulb burns out, the filament in the bulb falls across its sup- ports creating a momentary short circuit across the A C line. I have had three BSR units damaged when a bulb has gone out. Once it in- volved a single table lamp with a 70-watt bulb. Another time the failure occurred in a wall-switch module control- ling my outdoor-perimeter circuit of 400 watts. This seemingly practical and low-cost method of home control becomes some- thing of a folly when you find that you must replace a $16 control module because a $0.69 bulb has burnt out. I have not been able to return modules for replacements, because the salespeople ac- cuse me of overloading the module. In the future, I hope that the design of these modules will include protection against the surge that occurs when a light bulb fails. Until then, 1 don't think they are all that practical and probably should not be committed to serious uses (for which they are advertised), such as a burglar deterrent. Chris Gundlach Huntington VW /, too, have noticed that situation, and I've mentioned it to BSR. They are aware of the problem, but there isn't much that can be done to totally eliminate "zapping" the module except installing a 50 A Mac (the cost would be prohibitive). There aren't too many ways to achieve fold- back current-limiting in a triac. Don't feel too bad. I've lost seven modules and a control- ler because of various prob- lems, such as transients and blown bulbs. While the BSR unit is still cost-effective in consumer applications, I would be wary of it in critical control situations. A few companies have asked me about using the BSR for industrial remote- control and solar-hearing sys- tems, and I told them essen- tially what you have said to me. The application, of course, determines the ultimate interface selection. When the alternative is a thousand- dollar computer front end, the BSR may still be the best choice— even if a receiver has to be replaced once in a while.... Steve The following is a letter sent to me concerning Mr Gundlach's problem, from BSR.... Steve BSR Responds to Criticism Dear Mr Gundlach, You are correct in your identification of the problem. All commercially available dimmers that contain triacs, as our lamp- and wall-switch modules do, are subject to zapping if a blown light-bulb filament falls in a "short cir- cuit" position instead of open circuit. Since the introduction of the System X-10 in the fall of 1978, all products have been updated and improved as ne- cessary. We now use triacs «d^ on oD\^ 5 .•r^jafr . tftf^ oos ves *q$& *i$SS** ^o*. 30°\*c S ° V\\e tep' tt«ss .car* 1 s^m w^ e * ,oUP (0 " .S49 .00 >w^, 1 fe*^ S !!» -C^OS .s> 49 ■' oo a pa c '^ "Opf i toe.' icpp c «****■ \fillOS A^S*?iSP^7* ^VO^ 1^ CO V* ftf) 330 April 1981 © BYTE Publications Inc Circle 237 on Inquiry card. that we feel are most resistant to zapping. Our overall re- turn rate is quite low, and has steadily decreased with re- spect to blown triacs. This is substantiated in part by the fact that the major retail chains continue to buy our products in large quantities and would not do so if there were persistent problems. We are shipping you replacements for your failed units at no charge. I would greatly appreciate any feed- back on performance that you care to give... good or bad I Sorry you had some dif- ficulties. Peter A Lesser Vice President General Manager X-10 Division BSR Inc The Two Can't Connect Dear Steve, I have an early (second year of production) Radio Shack TRS-80 Model I 16 K-byte Level II computer that I'm having trouble add- ing peripherals to. I have a Quick Printer II, an Exatron Stringy Floppy, and a type- writer interface, each of which can be plugged into the expansion connector of the TRS-80 keyboard unit. I also have a l-into-2 cable that should allow me to use two peripherals at once. However, if more than one peripheral is plugged into the cable, the computer random- ly executes the initial power- up routine — destroying whatever I was working on. It doesn't seem to matter which peripherals I try to combine, nor does it matter if one is off. I don't think the problem is in the cable, be- cause it works well with each of the peripherals singly and in either connection. What could this be? I'd like to use the system for text pro- cessing, but that's impossible right now. Ron Tye Long Beach CA The TRS-80 Model I some- times does strange things when cables are connected to the keyboard. The longer the cables, the more likely the problem you described. With one peripheral installed, it may work properly, but when the load of another is added, the bus signals be- come sensitive to noise. Keeping the cables as short as possible helps. The solution is to either add a circuit that buffers all the signals from the keyboard or, at the very least, actively terminate the extension cable. If you do not mind a little soldering, you can try ter- minating your present cable. At the end of the cable, from each signal, attach a 1 k-ohm resistor to +5 V and a 470- ohm resistor to ground. You'll have to add a separate 5 V supply, since +5 Vis not available on the keyboard connector. . . . StcveB In "Ask BYTE," Steve Garcia answers questions on any area of microcomputing. The most representative questions received each month will be answered and published. Do you have a nag- ging problem? Send your inquiry to: Ask BYTE c/o Steve Garcia POB 582 Glastonbury CT 06033 If you are a subscriber to The Source, send your questions by electronic mail or chat with Steve (TCE3I7) directly. Due to the high volume of inquiries, personal replies cannot be given. Be sure to include "Ask BYTE" in the address. SOflG OF ROLRflD software APPLE and ATARI IOWA AVE. CITYJA. 52240 MASTERCHARGE BEOWULF Clash swords with the monster Grendel. If you win the battle, smack your lips and feast in the great hall. $19.95 THE HIGH PRIEST Learn secrets known only to the gods. Foretell good fortune, beware of bad. But don't ask the questions, if you don't want to k now the answers. $19.95 HUMBABA WILL GET YOU Outside, in the dark of the night, he lurks, waiting to rip your arm out of its socket. Youronlydefense is your wits and reaction time. Beware. $19.95 1-800-227-1617 operator 364 in California) 800-772-3545 operator 364 Circle 238 on inquiry card. April 1981 © BYTE Publications Inc 331 Event Queue April 1981 April-June Microprocessor Software, Hardware, and Interfacing, various cities throughout the United States. This hands-on course provides a foundation in the skills required for the design, programming, and real-world interfacing of microprocessor applications. For further details and a schedule of meeting places and times, contact Integrated Computer Systems Inc, 3304 Pico Blvd, POB 5339, Santa Monica CA 90405, (213) 450-2060. April-October Computer Sales-Marketing Workshops, various cities throughout the United States. These workshops are de- signed for retail salespeople and computer-marketing managers and their staffs. For a schedule of times and loca- tions, contact Datasearch Inc, 4954 William Arnold Rd, Department C, Memphis TN 38117, (901) 761-9090. April 1-2 Communications in the Twenty-First Century, Philip Morris Operations Center, Richmond VA. This con- ference will focus on tech- nological advances and their economic, political, social, and psychological implica- tions. Elie Abel, Professor of Communications at Stanford University, and Lord Briggs, provost of Worcester Col- lege, Oxford, England, are the keynote speakers. For in- formation, contact the man- ager of Media Relations, Philip Morris Inc, 100 Park Ave, New York NY 10017. April 1-3 Assuring Quality in Elec- tronic Data-Processing Ap- plications, McCormick Inn Hotel, Chicago IL. The objec- What is a CLOCALPEEP? Another name for the CCB-II, which is: • a clock hour, minute, second • a calendar day, day of week, month, year • an audio alarm All on one board foryour TRS-80 Model II It includes a pacemaker battery which will give over 8 years of continuous timekeeping. From the folks who brought you the best CP/lvT forthe Model II. $175 plus shipping Prepaid, COD, Mastercharge or Visa orders accepted. California residents add 6% sales tax. TRS-80 is a trademark of Tandy Corp. CP/M is a registered trademark of Digital Research Inc. Kg «5>SF PICKLES & TROUT P.O. BOX 1206, GOLETA. CA 93116. (805) 967-9563 Warning: Installation requires opening the Model II. which may void its warranty. We suggest that you wait until the warranty period has expired before installing the CCB-II. tive of this conference is to explain the methods, tools, and techniques that are valu- able in improving the quality of computerized applications. Tutorials cover the areas of quality assurance; managing structured design; and de- signing, implementing, and enforcing application stan- dards. Contact DPMA Quali- ty Assurance Conference, 12611 Davan Dr, Silver Spring MD 20904, (301) 622-0066. April 3-5 The Sixth West Coast Com- puter Faire, Civic Auditori- um, San Francisco CA. The Faire, a major personal-com- puting event, has continually attracted larger and larger numbers of exhibitors and at- tendees. A full program of talks plus a large display of hardware and software are featured. For more informa- tion, contact Computer Faire, 333 Swett Rd, Woodside CA 94062, (415) 851-7075. April 4 The Third Annual RAMS Spring Computer Show, Perinton Square Mall, Fair- port NY. This event is spon- sored by the Rochester Area Microcomputer Society. For more information, contact RAMS, POB D, Rochester NY 14609. April 7-8 Top Secrets '81, Pointe Resort, Phoenix AZ. Honey- well's annual computer secur- ity and privacy conference. Many data-security author- ities will discuss the business and legal impact of the latest incidents in computer crime and abuse. The conference fee is $500. Contact the Se- curity Symposium Registrar, Honeywell Information Sys- tems, M/S T-99-4, POB 6000, Phoenix AZ 85005, (800) 528-5343; in Arizona (602) 249-7954. April 7-9 Computerized Office Equip- ment Expo — Midwest '81, O'Hare Exposition Center, Rosemont IL. This exposition has exhibits and seminars on the use of computers and re- lated equipment in business environments. For details, contact Industrial & Scientific Conference Management Inc, 222 W Adams St, Chicago II 60606, (312) 263-4866. April 7-9 Electro/81, New York Coliseum and Sheraton Cen- tre Hotel, New York NY. Electro/81 will feature com- puters and computer-related equipment, plus seminars on components, devices, and materials; computer com- munications; memories; of- fice automation; speech; and more. Contact Electronic Conventions Inc, 999 N Sepulveda Blvd, Suite 410, El Segundo CA 90245, (800) 421-6816; in California (213) 772-2965. April 9-12 Southwest Computer Show and Office Equipment Ex- position, Market Hall, Dallas Market Center, Dallas TX. Hardware and software for business, education, govern- ment, home and personal use will be featured. Mini- and microcomputers, office machines, supplies and ser- vices, graphics equipment, and word processing will also be exhibited. Contact Na- tional Computer Shows, 824 Boylston St, Chestnut Hill MA 02167, (617) 739-2000. April 10-11 The Eleventh Annual VCUC Conference, Sheraton Red Lion Inn, Blacksburg VA. The VCUC (Virginia Com- puter Users Conference), a division of the ACM (Associ- ation for Computing Ma- chinery), and the Computer Science Department of the Virginia Polytechnic Institute and State University are holding this conference. The themes are "Personal Com- puting" and "System Perfor- mance." Write to ] Rosow or S Haldeman, VCUC 11, 562 McBryde Hall, VPI and SU, Blacksburg VA 24061. 332 April 1981 © BYTE Publications Inc Circle 239 on Inquiry card. Circle 240 on inquiry card. Circle 241 on inquiry card. DIGITAL DATA RECORDER MODEL CC-9B For five years now, the CC series recorders have been the industry NRZ Asynchronous recorder standard. Now the D series sets a new standard in stability and reliability with its tachometer feedback LC stabilized motor circuit. • 4800 or 9600 Baud (3" or 6" per second) • lCf 8 Error Rate RS232 or TTL In and Out • RTS motor start • CTS Data start • DB 25 or special connector optional • 110/220- 50/60 Hz • Wow & Flutter ± .3% • Speed Stability (long term) + .l% DC1 Model Price $275.00 DC2 Model Price $285.00 NATIONAL MULTIPLEX CORPORATION 260 Lackland Drive East Middlesex, New Jersey 08846 Tel. (201) 356-9200 TWX 710-997-9530 EVADA ForCP/M Powerful subset of ANSI-74 Why wait? All the elegant simplicity of COBOL la now affordable! $ DISK 99 95 5^ J REQUIRES only 16K RAM. Available on 8" CP/M standard single density or SW diskettes for North Star, TRS-80 Mod I and Superbraln. Other formats tool Manual alone $24.95. > <*e> Ellis Computing ^^ 600-41 >t Avenue San Francisco, CA 941 21 U.SJL. These powerful, easy to use COBOL APPLICATION PACKAGES are also available: 1. BUDGET PLAN REPORT GENERATOR Fantastic time saver and planning aid for beginning or established businesses. 2. PERSONAL FINANCIAL REPORTING Eye-opening Insights of personal spending. 3. LABELS for mailing lists. 4. PRECOBOL (a preprocessor). ALL 4 In one BOOK! 73 pages with complete COBOL source code listings and super documentation. $24 95 WE WELCOME CO. D.'s /^ffl-^^ (415) 751-1522 la CA add »•!•» t*». CP/M trada mark of Wflltal Hataarch. TR8-80 trade mack ot Tandy Corp. REFURBISHED TERMINAL SALE! A limited offer from Data Access Systems, Inc., in addition to their full line of new products. MFR/MODEL SALE PRICE DESCRIPTION Lear Siegler ADM-3 $525 Video terminal. Texas Instruments 725 $300 Portable thermal printer with built-in coupler- 735 $650 Portable thermal printer with built-in coupler. 745 (limited ASCII keyboard) $1175 Portable thermal printer with built in coupler. 745 (lull ASCII keyboard) $1225 Portable thermal printer with built-in coupler. 735 KSR $600 Desktop thermal printer. Digital Equipment LS-120 $1450 132 column 180 CPS printer. LA-36 $750 132 column 30 CPS printer with E.I.A. ADDS Regent 20 (new) $595 Video terminal. Regent 25 (new) $775 Video terminal. All units are DASI factory refurbished and in good working condi- tion. Includes 30-day parts and labor warranty, on site. Call your local DASI office, or toll free: (800) 257-7748. In N.J. (800)232-6510. Corporate Offices: Cole Rd. & Camden Ave.. P.O. Box 1230. Blackwood. NJ 08012. (609)2280700. Toll Free (800) 257-7748. In New Jersey. (800) 232-6510. District Ottlcti : Atlanta (404) 449-5435. Austm-(512) 474- 9643. Boston-1617) 769-6420. Chicago-OH) 9670440. Cincmnati(513) 793-9714. Cleveland-(216) 473-2131. Dallas- (214)256-5536. Denver(303) 741-2922. Detroit(313)S89-1409. Hartlord(203) 674-1697. Houston-(713) 682-5965. Los Angeles-(213) 618-0400. Milwaukee-(414) 963-9006. Mmneapolis-(S12) 854-4466. New Jersey-(201) 227-8880. New York City (212) 564-9301. Orange County-(714)979-21S7. Philadelphia(215) 667-8315. Phoemx-(602) 263-5034. Portland(S03) 644-8600. Rochester(716) 377 2090. St. Louis(3U) 576-2804. San Antomo-1512) 655-3274. San Francisco(415) 872-1811. San Jose-(408) 244-3772. Seattle-(20€) 251-5070. Washington. DC (301) 459-3377. * D/fl *S; DATA ACCESS SYSTEMS INC Computer I j Pr ogrammirtf t BASIC / « i'.\.- -:-■.■■" y*:'.---m t9 *liE5}* t V-iiZ** Computer \ Programming in 1 BA tsum war * Computer Programming BASIC Microcomputers are coming — ride the wave! Learn to program with a new course written for the beginner. Learn BASIC the lan- guage of the small computer and the most easy-to-learn computer language in widespread use. A self-instruction course that takes you from complete ignorance to real proficiency with a unique style of graded hints. 60 illustrated les- sons teach the five essentials of good programming: problem defi- nition; flowcharting; coding the program; debugging; clear docu- mentation. And you don't even need a computer! Price: $22.95 Send check with order to:- Cambridge Learning Inc., 1 Judith Drive North Reading, MA 01864 or call (617) 664-3657 with Mastercard or VISA Mass. residents add 5% Sales Tax Also available: Digital Computer Logic and Electronics This course is designed as an in- troduction to digital electronics and is written at a pace that suits the raw beginner. No mathemati- cal knowledge is assumed other than the use of simple arithmetic and decimals, and no electronic knowledge is expected at all. The course moves painstakingly through all the basic concepts of digital electronics in a simple and concise fashion: questions and answers on every page make sure that all the points are understood. Price: $14.95 Design of Digital Systems Written in a similar question and answer style to Digital Computer Logic and Electronics, this course moves at a much faster pace and goes into the subject in greater depth. Ideally suited for scientists or engineers wanting to know more about digital electronics, its six A size volumes lead step by step through number systems and Boolean algebra to memories, counters and arithmetic circuits and finally to an understanding of calculator and computer design. Price: $19.95 $5.00 discount for orders over $30.00. All prices include surface shipping For Airmail add $10.00 CAMBRIDGE LEARNING INC. Circle 243 on inquiry card. BYTE April 1981 333 Event Queue. April 13-14 The Executive Computer Conference, Washington DC. The theme of this 2-day meeting is "Improving Orga- nizational Productivity through Systems Technolo- gy." Special emphasis will be placed on management's perspective of the contribu- tions the computer has made to organizational productivi- ty. For information, contact Kendall E Burroughs, The Ex- ecutive Computer Con- ference, 1730 N Lynn St, Suite 400, Arlington VA 22209, (703) 521-6209. April 13-16 The Fifteenth International Symposium on Minicomput- ers and Microcomputers, MIMI '81, Sheraton Hotel, Mexico City, Mexico. The scope of this symposium covers hardware, software, distributed processor ar- chitecture, computer net- works, telecommunications, real-time applications, educa- tion, and more. Contact Ing. Jorge Gil, Academic Secre- tary, MIMI Symposium, IIMAS-UNAM, Apartado Postal 20-726, Mexico 20 D F, Mexico. April 14-16 The Seventh Annual Federal DP Expo, Sheraton Washing- ton Hotel, Washington DC. This conference and exposi- tion is for computer-system users in the US government. More than 150 exhibitors and over 100 speakers will high- light the event. Contact The Interface Group, 160 Speen St, Framingham MA 01701, (800) 225-4620; in Massa- chusetts, call (617) 879-4502. April 25-26 Trenton Computer Festival, Trenton State College, Tren- ton NJ. This annual flea market and swap meet of personal-computer equip- ment also features speakers, user-group meetings, and an exhibit of commercial prod- ucts. It is sponsored by the Amateur Computer Group of New Jersey, the Philadelphia Area Computer Society, and Selectric® Interface System EiASILY interfaced to any IBM Selectric I, II, or III. OTOP spinning your wheels. Letter qual- ity at an affordable price. CONNECTS via Parallel or RS-232, ac- commodates varied handshaking. o N NLY S575 to $599. Dealer inquiries in- vited. EW design provides added features. ESCON Products, Inc. 12919 Alcosta Blvd. San Ramon, Ca., 94583 (415) 820-1256 the Trenton State Computer Society. Contact TCF-81, Trenton State College, Tren- ton NJ 08625, (609) 771-2487. April 26-30 Saudibusiness '81, Riyadh, Saudi Arabia. This show has been designed for the fast- growing Saudi Arabian busi- ness community. Pavilions by the United States, the United Kingdom, West Ger- many, France, Italy, and ap- proximately fifteen other countries will be featured. For more information, con- tact Donald Ryan, Project Manager, Rm 3200, US De- partment of Commerce, Washington DC 20230, (202) 377-4652. April 27-30 National Design Engineering Show and Conference, Mc- Cormick Place, Chicago IL. The theme of this show is "Computers Throughout the Design Function." Addition- ally, the principal areas of consideration are design management, computer- aided design, materials, mechanical components and systems, and electronics. Contact Clapp & Poliak Inc, 245 Park Ave, New York NY 10167, (212) 661-8410. April 30-May 1 An Assessment and Forecast of Computer Graphics, Sad- dle Brook Marriott, Saddle Brook NJ. This annual con- ference will assess the present state of computer graphics and will evaluate hardware, software, systems services, and applications. The impact of new technologies on com- puter graphics and the role of graphics in business will be discussed. Contact Bob San- zo, Frost & Sullivan Inc, 106 Fulton St, New York NY 10038, (212) 233-1080. May 1981 May 2 National Computer Problem- Solving Contest for Junior and Senior High School Stu- dents, throughout the US. Small teams of junior and senior high school students will compete for two hours on computer systems to solve five programming problems. Winners will be judged on whether their programs run properly using the test data supplied in the problem, are easy to read, and are logical, imaginative, and creative. To receive a copy of the 1981 contest problems, local school directors should con- tact the University of Wis- consin — Parkside by April 4. Directors must agree to keep the problems confidential un- til the day of the contest. After that, any organization can use the problems to con- duct its own contest. Local contest winners can enter the national and international contest. A national and worldwide ranking will be determined by a team of judges from the University of Wisconsin — Parkside. All in- terested schools or organiza- tions can share the 1981 con- test problems. For additional informa- tion, write Dr Donald T Piele, Associate Professor of Mathematics, University of Wisconsin — Parkside, Keno- sha WI 53141. May 4-7 National Computer Con- ference, McCormick PI, Chicago IL. Approximately 90,000 people are expected to attend this year's National Computer Conference (NCC). The use of robots and artificial intelligence will be among the program sessions at the Personal Computing Festival during the NCC. This will be the first time that personal-computing exhibits have joined the rest of the conference in the main ex- hibit area. Over thirty technical sessions will be held. All major companies will be represented. Contact the American Federation of Information Processing Societies Inc, POB 9658, 1815 N Lynn St, Arlington VA 22209, (703) 558-3617. May 5-8 INTELCOM 81 /Paris, Paris, France. INTELCOM (Inter- national Telecommunications and Computer Conference and Exhibition) 81 /Paris is 334 April 1981 © BYTE Publications Inc Circle 244 on Inquiry card. part of a program to promote an international dialogue on vital subjects in the telecom- munications field. This con- ference attempts to guide the evolution of the computer and its technology by com- bining the efforts of private companies, government, and equipment users. For infor- mation about attending, pre- senting a paper, or exhibiting at INTELCOM 81/Paris, contact the Conference Af- fairs Group, Horizon House, 610 Washington St, Dedham MA 02026, (800) 225-9977; in Massachusetts (617) 326- 8220. May 33-23 Fourth Annual Rosen Research Personal-Computer Forum, Playboy Resort, Lake Geneva WI. This forum fea- tures guest speakers from all the major personal-computer hardware and software com- panies. The Rosen Forum is one of the most prestigious and important seminars in the industry. For further details on this 3-day session, contact Rosen Research Inc, 200 Park Ave, New York NY 10166, (212) 586-3530. May 23-13 Custom Integrated Circuits Conference, CICC'81, Amer- icana Hotel, Rochester NY. The CICC aims to bring to- gether designers, producers, and users of custom inte- grated circuits to discuss re- cent developments and future directions in the field. Papers will be read on applications, algorithm-implementing in- tegrated circuits, fabrication techniques, interfaces and in- terconnects, computer-aided design, and testing and qualification. Contact Dr Rajinder Khosla, General Chairman, Research Labora- tories, B-81, Eastman Kodak Company, Rochester NY 14650, (716) 722-2525. May 11-13 The Thirty-First Electronic Components Conference, Colony Square Hotel, Atlan- ta GA. Papers will be read on semiconductor-processing technology, optoelectronic devices, manufacturing tech- nology, materials, hybrid microcircuits, discrete com- ponents, interconnections, reliability, and connectors. Contact T G Grau, Bell Lab- oratories, Whippany Rd, Rm 3B-312, Whippany NJ 07981; or Electronics Indus- tries Association, 2001 Eye St NW, Washington DC 20006. May 34-26 The Tenth ASIS Mid-Year Meeting, Fort Lewis College, Durango CO. The American Society for Information Science's (ASIS's) theme for this year's meeting is "Using Information." Among the topics to be addressed are user studies, decision making, organizational change, government, educa- tion, management, access to information, and designing information systems for use. For information, contact ASIS, 1010 16th St NW, Washington DC 20036, (202) 659-3644. May 27-20 Expo '81, Loew's Anatole Hotel, Dallas TX. Expo '81 is a combination of exhibits and technical sessions. The ex- hibits cover everything from graphics systems to industrial computer-control systems. The technical sessions range from tool design, design en- gineering, and robotics to numerical control. For more information, contact Num- erical Control Society, 519 Zenith Dr, Glenview IL 60025, (312) 297-5010. May 20-22 Joint Conference on Easier and More Productive Use of Computing Systems, Univer- sity of Michigan, Ann Arbor MI. This conference intends to combine the insights of the social sciences, humanities, computer science, and human-factors engineering. Contact Gregory A Marks, 4258 Institute for Social Research, University of Michigan, Ann Arbor MI 48106, (313) 763-3482. May 20-22 Videotex '81, Royal York Hotel, Toronto, Ontario, Canada. Videotext informa- tion systems allow users to call up information, make VERSION 3.0 It keeps getting better and better! Starting over a year ago with the original set of programs from Osborne & Associates, we have gradually developed a self- installing, reliable business package. A partial list of our enhancements: No-Hassle Installation. You simply select your desired configuration from a series of menus and go. There is no re- compiling necessary, except for some state payroll tax routines. CRT Independence. We support 16 terminal types directly, and provide a method for specifying more. We can make it run with your CRT - or your money back. File Access. Our GL account file lookups are much faster than the original. And now — with version 3.0 — we have doubled the number of accounts, customers, and ven- dors that can reside on a disk. There are many other im- provements — send for details. We believe our product to be the best Osborne-based business package available for CP/M- based microcomputers. We are committed to the ongoing sup- port of our users, through both a tech-support phone line and a generous upgrade policy. Vandata has been supplying ap- plications software for over eight years. Quality and support are our way of doing business. Our 30-day money-back guarantee speaks for itself. General Ledger with Cosh Journal $295 Accounts Receivable $295 Accounts Poyable $295 Payroll with Cost Accounting $295 All Fout Pockag.j (GL, AR, AP, PR) $995 Magic Wand (Super Word Processor!!) $345 Peorl Level III (best prog tool available) $645 CBASIC2 $110 TRS-80' MOD II CP/M- 2 2 (P 8, T) $185 H89/Z89CP/M- 2 2(Mognolia) $199 Formats Std. 8". 5" NorthStar DD, TRS-80 MOD ll» H89/Z89 Manuals (or GL, AR/AP, and PR are not in- cluded in price - odd $20 per manual desired (AR/AP are in one manual). CP/M and CBASIC-2 reguired to run accounting sofrwore Users must sign licensing agreement. Dealer inquiries invited. To order call: (206)542-8370 or write VANDATA 17541 Stone Ave. N. Seattle, WA 98133 CP/M" ts a registered trademark of Digital Research TRS-80" is a registered trodemark or Rodio Shack, Inc ■ "in. Circle 245 on inquiry card. April 1981 © BYTE Publications Inc 335 Event Queue. reservations, pay bills, ex- change electronic mail, read an electronic newspaper, shop, and play video games. This conference will review videotext developments in Europe, Japan, and North and South America. Demon- strations of videotext systems will be given. Seminars on standards, legal aspects, and economic issues will be fea- tured. Contact Videotex '81, 316 Lonsdale Rd, Suite 3, Toronto, Ontario, M4V 1X4, Canada, (416) 598-1981. May 21-23 Annual Conference of the Educational Computing Or- ganization of Ontario, Sheraton Centre and the On- tario Institute for Studies in Education, Toronto, On- tario, Canada. Exhibitions on the use of computers in schools and discussions on how to locate suitable educa- tional materials will be fea- tured. Contact the Con- ference Office, OISE, 252 Bloor St W, Toronto, On- tario, M5S 1V6, Canada. June 1981 June 6-9 Atlanta Small Computer Show, Atlanta Hilton, Atlan- ta GA. Producers of small computers, peripherals, sup- plies, and services will be ex- hibiting at this show. Busi- ness owners, corporate and government executives, data- processing managers, doc- tors, lawyers, and other pro- fessionals are expected to at- tend. Obtain additional in- formation from The Atlanta Small Computer Show, 4060 Janice Dr, Suite C-l, East Point GA 30344, (404) 767- 9798. June 9-11 Understanding and Using Computer Graphics, Chicago IL. This seminar covers the latest in graphic-system tech- nology, including hardware, software, and applications. Contact Bob Sanzo, Frost & Sullivan Inc, 106 Fulton St, New York NY 10038, (212) 233-1080. June 14-18 The Second National Con- ference of the National Com- puter Graphics Association, Baltimore Convention Cen- ter, Baltimore MD. Comput- er-graphics demonstrations, exhibits, and workshops will be held. Contact the National Computer Graphics Associa- tion Inc, 2033 M Street NW, Suite 330, Washington DC 20036, (202) 466-5895. June 16-18 NEPCON East '81, New York Coliseum, New York NY. This exposition is aimed at engineers, prototype devel- opers, production specialists and testing personnel. Tech- nical programs will be pre- sented. Contact Industrial & Scientific Conference Man- agement Inc, 222 W Adams St, Chicago IL 60606, (312) 263-4866. June 17-19 National Educational Com- puting Conference, North Texas State University, Den- ton TX. This conference will provide a forum for individ- uals and institutions inter- ested in educational comput- ing. Computer literacy, com- puter education for teachers, and computers in education are some of the topics to be covered. Contact Dr Jim Poirot, NECC-81 General Chairman, Computer Sciences Department, North Texas State University, Den- ton TX 76203. June 20-22 The Fifth Annual Com- puterfest, Franklin Universi- ty, Columbus OH. Talks on robots and calculators will be featured. Microcomputers and small-business systems will be presented. This show is being sponsored by the Midwest Affiliation of Com- puter Clubs and Franklin University. Contact Comput- erfest '81, Paul Pittenger, 215 Delhi Ave, Apt J, Columbus OH 43202, (614) 224-6237. June 29-July 1 The Nineteenth Annual Meeting of the Association for Computational Linguis- tics, Stanford University, Stanford CA. Syntax, pars- ing, and sentence generation, computational semantics, discourse analysis and speech acts, speech analysis and syn- thesis, machine and machine- aided translation, and mathe- matical foundations of com- putational linguistics are some of the topics to be discussed. Contact Don Walker, Artificial Intelligence Center, SRI International, Menlo Park CA 94025, (415) 326-6200, ext 3071. ■ BYTE's Bits Atari Slashes Prices Atari Inc has reduced the price of the Atari 400 com- puter with 8 K bytes of mem- ory to $530. The 16 K ex- panded version of the 400 is now selling for $630. Atari also reduced the Model 810 5V4-inch floppy-disk drive to $599.95. On another front, Atari plans to begin selling a $150 word-processing program later this year.B REAL TIME CLOCKS SciTronics introduces . . . with full Clock/Calendar Functions The Worry-free Clocks for People Who Don't Have Time to Worry!! What makes them worry-free? • Crystal controlled for high (.002%) accuracy • Lithium battery backup for contin- uous clock operation (6000 hrs!!!) • Complete software in BASIC- including programs to Set and Read clock • Clock generates interrupts (seconds, minutes, hour) for foreground/background operation Applications: • Logging Computer on time • Timing of events • Use it with the SciTronics Remote Controller for Real Time control of A.C. operated lights and ap- pliances Versions available for: • S-100 bus computers • Apple II computer • SciTronics RC-80 RTC-100 $159 RTC-A $129 RC-80CK $109 send SciTronics Inc. Check or 523 s ciewell St., P.O. Box 5344 order y io Bethlehem, PA 18015 (215) 868-7220 Please list system with which you plan to use controller • Master Charge and Visa accepted. COD's accepted. PA residence add sales tax. 336 April 1981 © BYTE Publications Inc Circle 246 on inquiry card. Circle 247 on inquiry card. Circle 248 on inquiry card. ■ fciiHieierstiii Boards for S-100 BUS from S.C. Digital "CPUI-Z80" Advanced Z8DA based CPU board S219 Assembled and Tested S149 Kit *(less Interrupt) Features: Model CPUI-Z80 • 2/4 Mhz SW selectable. • Built in 8 Prioritized Vectored Interrupts with 8 possible levels ot Nested Interrupts using powerful Mode 2 of Z80, all done in Hardware, expandable with external ckt. • Vector Jump on RESET, in 4K increments. • Supports 2K of EPROM (not supplied), DMA. dynarmic RAM refresh . . . many more. 'Kit comes with all parts except chips connected to Interrupts. "INTERFACE: 1" I/O, Memory Interface Board S229 Assembled and Tested SI 69 Kit Features: Model 3SPC • 3 Serial w RS232C or 20ma Current Loop, 1 Parallel. • 4K of EPROM/ROM and 4K of RAM (ROM/RAM not supplied). • Built in Kansas City Standard Cassette interface usable to 1200 Baud. • Generates all popular baud rates up to 19. 2Kbaud, including 110 Er 134.5. *> SW settable Address, Baud Rates, Ports. "UNISELECT" 16K Static RAM with universal Bank Select Model 16KUS S235 A ft T. with 200 nsec memory chips. All boards meet IEEE- S 1 00 standards. Fully socketed, solder masks, gold contacts, and guaranteed for one full year. Kit guaranteed parts, only. Delivery: from stock to 72 hours. Ordering: You may call for M.C., VisaorC.O.D. orders. (Add S4.00 for COD.) Personal checks ok., butM.0. speeds shipment. Takes? to 15 days to clear personal checks before shipping. Undamaged boards can be returned within 10 days for full refunds. Illinois residents add 5Vi% cajpc tav OEM. PRICING AVAILABLE, DEALER INQUIRY INVITED Sf\ r>" "4. I P.O. Box 906 Phone: .L». Uigital Aurora, I L 60507 (312)897-7749 MAIL ORDER DISCOUNTS tipple computer Sales and Service APPLE II PLUS 48K $1,175 APPLE III CALL FOR PRICES ACCESSORIES DISK II DRIVE & CONTROLLER (DOS 3,3) ....525 MICROSOFTZ-80SOFTCARDSYSTEM .. .290 DISK II DRIVE ONLY 455 MICROSOFT 16K RAM CARD 169 INTEGER BASIC FIRMWARE CARD .149 VIDEX 80 COLUMN BOARD & SWITCH .330 APPLESOFT II FIRMWARE CARD ...149 HAYES MICROMODEM II .315 M&RSUP-R-MODRF MODULATOR ... 30 LEEDEX 12" B&W MONITOR .149 CENTRONICS PRINTER INTERFACE CARD .179 SANYO 12" GREEN MONITOR 265 HIGHSPEED SERIAL INTERFACE CARD 145 SILENTYPE PRINTER W/INT CARD 535 SSM AIO SERIAUPARALLEL I/O CARD . .185 EPSON MX-80 PRINTER 620 LANGUAGE SYSTEM WfPASCAL ....420 MPI88G PRINTER 695 DAN PAYMAR LOWER CASE ADAPTER . .... 45 QUME SPRINT 5(45 PRINTER 2,550 SOFTWARE APPLE DOS TOOLKIT .... 65 APPLE FORTRAN .159 APPLE PLOT .... 60 APPLEWRITER . . 65 TAX PLANNER ... 99 DOW JONES PORTFOLIO EVALUATOR 45 APPLE PILOT . .125 DOW JONES NEWS & QUOTES REPORTER 85 VISICALC .119 THE CONTROLLER BUSINESS SYSTEM . 515 DESKTOP PLAN ... 79 SUPER INVADER (DISK) 23 CCA DATA MANAGEMENT .... 85 BASF 5'/." DISKETTE (10) .. 30 TO ORDER: Please send cashier's check, money order or personal check (allow 10 business days to clear). VISA and Master Card credit card service add 2%. American Express credit card service add 5%. Shipping, handling and insurance in U.S. add 3% (minimum $3). California residents add 6% sales tax. Foreign orders add 10% for shipping. Equipment is subject to price change and availability. All equipment carries factory warranty. TELEX: 697120 DATAMAX-SDG computer age. inc. Authorized Apple Dealer & Service Center 4688 CONVOY ST., SUITE 105, SAN DIEGO, CA 92111 (714) 565-4062 ~ " Clock/Calendar ComputeiWateh Now available on Three Buses Features *APPLE II • 12/24 Hr. Format • Month-Day-Year • Day of Week *TRS-80 • Leap Year Bit • 4 Interrupts • +-30 Sec. Adjust 1 • Battery Backup S1l • Simple to Program, S^ 50 FOB ' Apple is a Trademark of Apple Computer Co. COmpUTJm© " TRS80 is a Trademark of Tandy Corp. Dealer Inquire (714) 536-5000 P.O. Box 5343 Huntington Beach, CA 92646 Circle 249 on inquiry card. •8* Model EP-2A-87 EPROM Programmer NEW - CRT ENTRY MODE f°ni*u;" ■-■ The Model EP-2A-87 S Tc ?2">&ai «, c i EPROM Programmer has an RS-232 compatible interface and includes a 2K or 4K f.."fe-° t^jB M buffer During the ON-LINE Mf m mode, another computer can down-load to the buffer. Only two easy-to-implement commands are available to an external computer. (Load buffer and read buffer.) In the OFF-LINE mode, the EP-2A-87 will program, verify, test buffer, and load the buffer from the EPROM socket. During the programming cycle, the EPROM is checked before programming to insure that it is erased and after programming it automatically verifies that programming is correct. Power requirements are 115 VAC 50/60 Hertz at 15 watts. Pari No. Description Price EP-2A-87-1 Programmer with 2K buffer $575 00 F.P 2A-87 2 Programmer with 4K buffer 650.00 Non standard voltage option (220 v. 240 v. 100 v) 15,00 PM0 Personality Module, programs TMS 2708 18 00 PM 1 Personality module programs 2708 18.00 PM 2 Personality module programs 2732 34.00 PM 3 Personality module, programs TMS 2716 26.00 PM 4 Personality module, programs TMS 2532 34.00 PM5 Personality module, programs 2716. TMS 2516 18.00 PM6 Personality module, programs 2704 18(10 PM 7 Personality module, programs 2758. TMS 2508 18 00 PM 8 Personality module, programs Motorola MCM68764 36.00 Optimal Technology, Inc. r Blue Wood 127 **"* Earlysville, Virginia 22936 Phone (804) 973-5482 Circle 250 on inquiry card. BYTE April 1981 337 Circle 251 on inquiry card. Introducing The Benchmark WORD PROCESSING SYSTEM THE BENCHMARK software system sets new standards in word processing. First, it canbedeliveredtorunontheCP/M< B ortheNorthStarDOS.sotheremaybenoneed to buy a special operating system. Second, it has all the features of systems costing thousands of dollars more. Third, the price is as low as, or lower than, most word processing systems. Anyone can learn to run and use THE BENCHMARK in one day of self training. Completely self-prompting in English. THE BENCHMARK is a full capability word processor, has been thoroughly tested in an off ice environment and proved to meet the needs of the most sophisticated user. • Multi-operating system • Changes terminal drivers • Customized to utilize all the features of terminal S. printer ONLY $499 • Overtype - erases, corrects • Variable, electronic decimal tab • Screen menus simplify operation • Block move and get plus tax where applicable THE BENCHMARK is distributed by RSB Computer Systems. Dealer inquiries are invited. kp Computer 1954 E. University 1-800-528-7385 Systems Tempe, Arizona 85281 AZ-602-968-7101 THE BENCHMARK is a trademark of Metasoft Corporation CP/Misa registered trademark ot Digital Research • €p '^aocit etm ' or e than a ° d . «l 10,000 s^ ^ job- Ust* ana mcnoNAe ENGUS4 Books Received /Iduanced Micro Devices Condensed Catalog. Sunny- vale CA: Advanced Micro Devices Inc, 1981; 18 by 24.5 cm, 147 pages, softcover, no ISBN, free of charge. COBOL, A Vehicle for In- formation Systems, Robert T Grauer. Englewood Cliffs NJ: Prentice-Hall Inc, 1981; 19 by 24.5 cm, 432 pages, hard- cover, ISBN 0-13-139709-5, $18.95. The Creative Kid's Guide to Home Computers, Fred D'Ignazio. Garden City NY: Doubleday & Company Inc, 1981; 16 by 24 cm, 130 pages, hardcover, ISBN 0-385- 15313-9, $9.95. Digital Electronics Troubleshooting, Joseph J Carr. Blue Ridge Summit PA; Tab Books Inc, 1981; 13 by 21 cm, 350 pages, softcover, ISBN 0-8306-1250-5, $9.95; hardcover, ISBN 0-8306- 9677-6, $16.95. The Effective EDP Man- ager, Michael R Frank. New York: AMACOM, 1980; 16 by 23.5 cm, 197 pages, hard- cover, ISBN 0-8144-5635-9, $17.95. Experiments in Amplifiers, Filters, Oscillators, and Generators, Morris Tischler. New York: McGraw-Hill Book Company, Gregg Divi- sion, 1981; 22 by 28 cm, 170 pages, softcover, ISBN 0-07-064780-1, $6.95. Experiments in General and Biomedical Instrumenta- tion, Morris Tischler. New York: McGraw-Hill Book Company, Gregg Division, 1981; 22 by 28 cm, 201 pages, softcover, ISBN 0-07- 064781-X, $8.95. Experiments in Telecom- munications, Morris Tis- chler. New York: McGraw- Hill Book Company, Gregg Division, 1981; 22 by 28 cm, 186 pages, softcover, ISBN 0-07-064782-8, $7.95. The FORTRAN Cook- book, Thomas P Dence. Blue Ridge Summit PA: Tab Books Inc, 1980; 13 by 21 cm, 334 pages, softcover, ISBN 338 April 1981 © BYTE Publicarions Inc Circle 252 on Inquiry card. MICROSTAT NOW AVAILABLE FOR CBASIC2* MICROSTAT is the statistics package for microcomputers, and is proving itself to users around the world, including: Stanford, Harvard, Johnson & Johnson, Duke, University of Wash- ington, UCLA, Lockheed, University of Pennsylvania, Oklahoma State, U.S. Geological Survey, Monsanto, University of Toronto, Sweden's National Central Bureau of Statistics, Utah State, Butler University, SUNY, Van Camps, Texas ASM, University of Wisconsin and a growing list of other organizations. MICROSTAT's Data Man- agement Subsystem (DMS) makes creating your own data files easy and includes numerous editing and transformation capabilities. Files produced by DMS can then be used to generate statistics in all com- mon statistical areas (e.g., descriptive statistics, ANOVA, correlation, multiple regression, probability and hypothesis tests, nonparametrics and others) plus some not so common ones. Whether pure reserch or industrial quality control, MICROSTAT is the statistics package for you. MICROSTAT sells for $250.00 and is supplied on 8" SD or 564K unit is 48K unit with Microsoft 16K RAM board. IMPORTANT NOTE: We will repair all Apple equipment regardless of where you purchased it. Disk II & Controller 3.3 Disk II Moniters,Sanyo9" B&W 12"B&W 12"Grn. 13" Col. RF Modulator, M&R Silentype printer Qume Sprint 5 45RO Serial Interface Card Apple Writer program Visicalc 80 Column Video: Apple Smarterm M&R, SupeRterm Videx, Language/Pascal Sys. Apple Plot Apple Pilot Microsoft: Z80 Softcard 16K RAM Card Paper Tiger printer Tiger to Apple cable Epson MX 80 W/lnterface DC Hayes Micromodem 16K Expansion RAM Kit 10 Memorex 5" disks 10 3M Scotch 5" disks 10 Maxell 5" disks Accounting Sofware, "Insoft Accountant" $ 365 66% (a full professional quality integrated GL.A/R.A/P, Payroll package with hotline support). Send for free sample printouts. Above prices for mail orders only Mail Order Dept. located in Jacksonville. OR. Our store showroom is at 126 NE F St., Grants Pass, OR. Store prices include service and will differ. No mail order sales at store. CALL ORDER DESK: (800)547-1289 TECHNICAL & OREGON: (503) 899-7297 ORDERING INFORMATION: Minimum order $100. Money Orders, Cashier Checks or Bank Wire Welcomed. Visa and MC orders add 3%. Personal checks accepted (allow up to 20 days to clear). All orders add 3% for shipping, handling and in- surance. Include your telephone number. No COD's. Prices subject to change without notice. Order desk hours are 9 to 6 PST. 10 to 3 Saturdays COMPUTER EXCHANGE MAILORDER DEPARTMENTOF , 6 OUTPUT POWER SUPPLY FLOPPY, EPROM, CPU ETC. BWAND NEW NORTH: 13670 IMled t>0'»S Ono us.vi .n NCn coil.it terminals. SV/3A, 24V/1 ?A, 16W28A (nil adjustable, w /ov prol ft cm limiting): 12V/0 1A. -24V/0.3A ihoih »/OV prnr | -W0 1A (,id| I Ful requlalpd consiTVEilivp linear op*ian partially ?nc1 W/SCM) assy (twigs tbeofy'5«ire docs 3 5*55* 14 115VAC Ru"sa"fl lloppy m drop the It lo 13V and run ?-3 mimtloppies r,uiiianlwKl S35 e» ■ I? It'i UPS Writ I tor atgmn ',i.|>llll.-'S mi-'iv.ry . Ii TERMS: UPS COD, \ NJ .wid sal'?* tax ELECTRAVALUE INDUSTRIAL PO BOX 157-B Pyfl MORRIS PtAINS. NJ 07<150 r'Ak, 201/267-1117 wabash When it comes to Flexible Disks, nobody does it better than Wabash. MasterCard. Visa Accepted. Call Free: (800)235-4137 PACIFIC EXCHANGES 100 Foothill Blvd San Luis Obispo. CA 93401 (In Cal call (80S) 543-1037] Circle 263 on inquiry card. Circle 265 on Inquiry card. Of Your HP-85 or Commodore System Building Blocks the POWER Pet/CBM With TNW's IEEE-488 Bus TNW-2000 TNW's RS-232 SERIAL INTERFACES Connect your PET/CBM to any RS-232 Serial Printer. Plotter. Terminal. Modem, or other device. CRT TNW-10Q0 TNW-2000 TNW-232D ONECHANNEL OUTPUT ONLY ONECHANNEL INPUT AND OUTPUT TWO CHANNELS. INPUT & OUTPUT 12 RS-232 CONTROL SIGNALS $129 $229 $369 TURN YOUR PET INTO A TERMINAL Access Timesharing Systems and Bulletin Boards with TNW's Pterm Software and full service telephone modem: TNW-103 AUTO ANSWER/AUTO DIAL USE WITH DAA $389 Pterm also works with acoustical couplers and other modems interfaced to the PET with the TNW-2000 or TNW-232D. Electronic mail and TWX Terminal programs also available. All units are addressable IEEE-488 devices, complete with power supply cabinet, full documentation and one year warranty. TNW CORPORATION 3351 Hancock St. • San Diego, CA., 92110(714) 225-1040 TWX910-335-1194 Visa/Mastercharge Welcome • Dealer inquiries invited DIGIAC MAPS 1 000 MP/M'S HARDWARE PARTNER 'The Dlglac MAPS-1000 MP/M" Universal Support Module has been designed to meet the total demands required by Digital Research's MP/M multi-user, multi-tasking operating system. All Input/output, Interrupt generation tor task switching, and disk bootstrapping are resident functions on the MAPS-1000. 'The MAPS-1000 has been designed with all the following powerful features: • Four (4) independent RS-232C Serial Communication channels • One 8 bit TTL parallel port • On-board phantom controlled disk boot prom/monitor • Power on jump capability • Crystal controlled MP/M interrupt generation Logic • On board extended memory bank switching Logic • MAPS-1000 fully assembled and tested price. . . S425.00 DIGIAC CORPORATION 175 Engineers Road Smithtown, New York 11787 Phone (516) 273-8600 MP/M is a trademark ot the Digital Research Corporation Apple en castellano Tercer Medio presenta su sistema administrative) (T.M.A.) para Apple ][ Disenado de acuerdo con los principios contables aceptados en todos los pai'ses de habla hispana. APLICACIONES COMERCIALES YCIENTIFICAS • CONTABILIDAD • CUENTAS GENERAL POR COBRAR Diario General Resumen del Diario Consulta parcial al Diario Mayor General Balance de Comprobacion Balance General Ganancias y Perdidas Catalogos de Cuentas Consultas por pantalla Catalogo de Cuentas Listado de Transacciones Antiguedad de Saldos Saldos por Veneer Relacion de Cobranzas Relacion de Pagos Estado de Cuentas Consultas varias por pantalla INVENTARIO Y FACTURACION CONTROL DE BANCOS PERT/CPM CUENTAS A PAGAR CONTROL DE COSTO DE OBRAS VENTAJAS DEL SISTEMA T.M.A. Son completamentes conversacionales. El chequeo de la informacion es instantaneo. Los reportes impresos o por pantalla guardan los formatos generalmente aceptados. Estan pensados para adaptarse a cualquier empresa. Toda la informacion esta instantaneamente disponible. Precision Expandida. Numeros de hasta ± 999.999.999.99 a Tercer Medio Sistema de Informacion C.A. APARTADO DE CORREOS 62533 CARACAS 1060-A - VENEZUELA TELEX: 27.876 - CPBTH -VE. TELEFONOS: 283.60.88 - 284.74.68 'Apple esmarca reqistrada pot APPLF COMPUTER INC Circle 266 on Inquiry card. Circle 267 on Inquiry card. BYTE April 1981 343 Software Received This following is a list of software packages that have been received by BYTE Publications during the past month. The list is correct to the best of our knowledge, but it is not meant to be a full description of the product or the forms in which the product is available. In particular, some packages may be sold for several machines or in both cassette and floppy-disk format; the product listed here is the version received by BYTE Publications. This is an all-inclusive list that makes no comment on the quality or usefulness of the software listed. We regret that we cannot review every software package we receive. Instead, this list is meant to be a monthly acknowledgment of these packages and the companies that sent them. All software received is considered to be on loan to BYTE and is returned to the manufacturer after a set period of time. Companies sending software packages should be sure to include the list price of the packages and (where appro- priate) the alternate forms in which they are available. Apple ABM, graphics arcade game for the Apple II. Floppy disk, $24.95. Muse, 330 N Charles St, Baltimore MD 21201. Action Sounds and Hi-Res Scrolling, sound and graphics utility for the Apple II. Flop- py disk, $15.95. Avant- Garde Creations, POB 30161, Eugene OR 97403. Animal Bingo, nonviolent strategy game for the Apple II. Floppy disk, $9.95. Avant- Garde Creations (see above). Apex Handy Disk #1, disk utilities for the Apex Oper- ating System (on the Apple II). Floppy disk, $39. Ap- parat Inc, 4401 S Tamarac Pky, Denver CO 80237. Asteron, game for the Apple II. Floppy disk, $27.50. Western Microdata Enterprises Ltd, POB 633, Postal Station G, Calgary, Alberta, T3A 2G1, Canada. Courseware Magazine, education programs and documentation for the Apple II. Cassette, $12.95 for a single issue or $50 for 5 issues. Courseware Magazine , School of Business, California State University, Fresno CA 93740. CRAE 2.0 (Co-Resident Apple Editor 2.0), Applesoft program editor for the Apple II. Floppy disk, $24.95. High- lands Computer Services, 14422 S E 132nd St, Renton WA 98055. The Creativity Life Dy- namic Book, graphics-, music-, and poetry-genera- tion game for the Apple II. Floppy disk, $19.95. Avant- Garde Creations (see above). Jungle Safari, graphics game for the Apple II. Floppy disk, $9.95. Avant-Garde Creations (see above). Masterdisk, disk-examina- tion utility for the Apple II. Floppy disk, $29.95. Master- works Software Inc, POB 7000-285, Rolling Hills Estates CA 90274. MCAT 2.0, disk-catalog utility for the Apple II. Flop- py disk, $19.95. Highlands Computer Services (see above). The Meaning Life Dy- namic, graphics-game pack- age for the Apple II. Floppy disk, $15.95. Avant-Garde Creations (see above). The Mine Fields of Nor- malcy, strategy game for the Apple II. Floppy disk, $9.95. Avant-Garde Creations (see above). Mystery Code, strategy game for the Apple II. Floppy disk, $9.95. Avant-Garde Creations (see above). Oldorf's Revenge, fantasy game for the Apple II. Floppy disk, $19.95. Highlands Computer Services (see above). Personal Property Inven- tory, cataloging utility for the Apple II. Floppy disk, $14.95. Hayden Book Com- pany Inc, 50 Essex St, Rochelle Park NJ 07662. The Prisoner, strategy game for the Apple II. Floppy disk, $29.95. Edu-Ware Ser- vices Inc, 22035 Burbank Blvd, Suite 223, Woodland Hills CA 91367. Sentence Diagramming, teaching program for the Apple II. Floppy disk, $19.95. Avant-Garde Crea- tions (see above). Star Avenger, graphics ar- cade game for the Apple II. Floppy disk, $27.50. Western Microdata Enterprises Ltd (see above). Tarturian, fantasy game for the Apple II. Floppy disk, $24.95. Highlands Computer Services (see above). VU #3, VisiCalc-based utility for the Apple II. Flop- py disk, $69.95. Progressive Software, POB 273, Ply- mouth Meeting PA 19462. XPLO, programming lan- guage for the Apple II. Flop- py disk, $79. Apparat Inc (see above). TRS-80 Attack Force w/Sound, graphics arcade game for the TRS-80. Cassette, $14.95. Big Five Software, POB 9078- 185, Van Nuys CA 91409. Beef Cattle Least-Cost Ra- tion Program, cost-analysis program for the TRS-80. Cas- sette, $5. Agricultural Soft- ware Consultants Inc, 1706 Santa Fe, Kingsville TX 78363. Blackjack Master, black- jack strategy game for the TRS-80. Hoppy disk, $24.95. Hayden Book Company Inc, 50 Essex St, Rochelle Park NJ 07662. Galaxy Invasion, graphics arcade game for the TRS-80. Cassette, $14.95. Big Five Software (see above). Personal Property Inven- tory, cataloging utility for the TRS-80. Floppy disk, $14.95. Hayden Book Company Inc (see above). Starclash, strategy game for the TRS-80. Floppy disk, $16.95. Hayden Book Com- pany Inc (see above). CP/M Communications Software Package, utility for CP/M systems. Floppy disk, $60. Datastat Systems Inc, 631 B St, San Diego CA 92101. Datastar, key-to-disk data- entry program for the CP/M operating system. Floppy disk, $350. MicroPro Interna- tional Corporation, 1299 Fourth St, San Rafael CA 94901. Pascal/M, programming language for the CP/M sys- tem. Eight-inch floppy disk, $175. Sorcim, POB 32505, San Jose CA 95152. Supersort I, record-sorting utility for the CP/M oper- ating system. Floppy disk, $250. MicroPro International Corporation (see above). WordMaster, video-based text editor for the CP/M op- erating system. Hoppy disk, $150. MicroPro International Corporation (see above). WordStar, word-pro- cessing program for the CP/M operating system. Floppy disk, $495. MicroPro International Corporation (see above). Other Computers Budget Manager, personal- utility program for the APF Imagination Machine. Cas- sette, $19.95. APF Elec- tronics, 1501 Broadway, New York NY 10036. Full Screen Editor, text- manipulation program for the Heath H-89. Floppy disk, $24.95. Heath Company, Benton Harbor MI 49022. Jinsam 8.0, data-base-man- agement program for the Commodore CBM 8032. Floppy disk, $175. Jini Micro- Systems Inc, POB 274, Kingsbridge Sta, Bronx NY 10463. Personal Business Ma- chine, personal-utility pro- gram for the APF Imagina- tion Machine. Cassette, $29.95. APF Electronics (see above). Ramscan, memory diag- nostic test for the Atari 800. Floppy disk, $15. Axlon Inc, 170 N Wolfe Rd, Sunnyvale CA 94086. Space, Size, and Surface Guide, personal-utility pro- gram for the APF Imagina- tion Machine. Cassette, $29.95. APF Electronics (see above). ■ 344 April 1981 © BYTE Publications Inc BYTE's Bits Results of "What Is It?" Contest In the April 1980 BYTE, we announced a contest. In the 'What's New?" section, on page 247, we printed a pic- ture of an anonymous me- chanical device and chal- lenged readers to identify it. The first person to respond with the correct answer was to receive the device as a prize. Tony Caloggero of Nahant, Massachusetts, won the contest. It is called Step- dozer, a product of the Gak- ken Company of Japan. The Stepdozer is part of a line of mechanical toys known as Space Mechanimals. Other readers sent in vary- ing descriptions of the beasty. Several readers stated that it was part of a cash register. One reader gave a specific description as a 1903 C L Smith adding machine, with the battery pack thrown in as a "red herring." Another reader guessed several pos- sibilities: "a doughnut dunker, an automatic pitch- fork, or a piece of my space- ship." Yet another suggested that it was a model of an oil pump. These descriptions were slightly off the mark. Several readers came closer, by describing it generically as "a walking machine." One reader said that he recognized it instantly as a "Rien de Toot," and we received one letter identifying the device as a "mechanical Trojan horse." Finally, we would like to quote extensively from a reader in University, Alabama, who wrote: Good heavens, any economist worth his salt knows the answer — it's a por- table widget, with a self- contained power source. It's used as a product example in almost every freshman eco- nomics course in the country. Get with it — you folks are slipping! Next time, show us something really hard to guess, like an inversely trun- cated framistan! Only if we can find one.B Photo 1: got it. A Stepdozer for Tony Caloggero. He guessed it, he f Radio /hack PROGRAMS - VV Snace-y ic Games Space-Action-Invaders Programmer's Tool Kit Write your own programs easier rr Many, many more! Books • Memory • Accessories Shipping from stock Call or Write: COMPUTERWARE I 6809 Specialists Dept. C • Box 668 Encinitas, CA 92024 (714) 436-3512 Computerware is a trademark of Computerware. Radio Shack is a registered trademark ol Tandy Corp. DISK DRIVE WOES? PRINTER INTERACTION? MEMORY LOSS? ERRATIC OPERATION? Don't Blame The Software! Power Line Spikes, Surges & Hash could be the culprit! Floppies, printers, memory & processor often interact! Our unique ISOLATORS eliminate equipment interaction AND curb damaging Power Line Spikes, Surges and Hash. • ISOLATOR (ISO-1) 3 filter isolated 3-prong sockets; integral Surge/Spike Suppression; 1875 W Maximum load, 1 KW load any socket $62.95 • ISOLATOR (ISO-2) 2 filter Isolated 3-prong socket banks; (6 sockets total); Integral Spike/Surge Suppression; 1875 W Max load, 1 KW either bank $62.95 • SUPER ISOLATOR (ISO-3), similar to ISO-1 except double filtering & Suppression $94.95 • ISOLATOR (ISO-4), similar to ISO-1 except unit has 6 Individually filtered sockets $106.95 • ISOLATOR (ISO-5), similar to ISO-2 except unit has 3 socket banks, 9 sockets total $87.95 • CIRCUIT BREAKER, any model (add-CB) Add $ 8.00 • CKT BRKR/SWITCH/PILOT(CBS) Add $16.00 Master-Charge, Visa, American Express Order Toll Free 1-800-225-4876 (except AK, HI, MA, PR & Canada) A&J Electronic Specialists, Inc. 171 South Main Street. Natick. Mass. 01760 Technical & Non-800: 1-617-655-1532 Circle 269 on inquiry card. Circle 270 on inquiry card. April 1981 © BYTE Publications Inc 345 k^ V w THE CONFIGURABLE BUSINESS SYSTEM IM is a parameter-driven information manager that makes the business of applying computers easier and more efficient. A pre-defined framework gives you the tools to design and implement your own well-documented system, including: • sophisticated data entry • concise data-based management system • user customized job streams and menus • personalized report generation User training and support is minimized by a comprehensive operating manual. CBS Disks can fit any 8080 or Z80 computer with CP/M* Disks and manual, $395; Manual only, $40. Your DMA representative can tell you about DMA. DOS, our CP/M compatible operating system, and ASCOM, an Asynchronous Communication Control Program. DMA • WE SPEAK YOUR LANGUAGE This publication is available in microform. University Microfilms International Please send additional information for. Name Street City State Zip 300 North Zeeb Road 30-32 Mortimer Street Dept. PR. Dept. RR. Ann Arbor, Mi. 48106 London WIN 7RA U.S.A. England 346 BYTE April 1981 Circle 65 on inquiry card. The business information you need at the turn of a key. Datadex is a new interactive business management system designed for the Apple personal computer. It's from IUS, the people who brought you EasyWriter™ and who are bringing you new products for office automation, education, and development systems. Datadex is short for data index. It lets you put all your business data into your Apple the way you like to see it and manipulate it any way you want. II adapts to your way of doing business. Want to generate a sales report? Just press four keys and fill in the blanks. That puts your sales data into the computer. Now, your report: Datadex designs it for you, based on what you've entered. Nothing to it. That's power! You can do the same with phone lists, mailing lists, dealer names or inventories. PUT OATAOGX IN YOUR APPLE. They all enter Datadex and form your own personal data base. Want to find a company but don't know how to spell its name? Try something that sounds close, and our Soundex routine will find it. It is very forgiving on typos and extra spaces. -< CHECKBOOK >■- OLOISIUS ZUKRZAWSK1 mMOUHT I 923 77 CROSS I 523.7? Soundex helped us find Mr. Zuki7,awski when we were balancing our checkbook. We weren 't sure how to spell Al's name, so searched for Al Z and found him. Instantly. The check register and several other applica- tions are free with Datadex. Want a specific piece of information, like sales for January 14-21? Inquire Datadex and the answer comes up on the screen right now. And right. Want a report of all sales in ZIP code areas starting with 9? Sure. Just ask it to print a report. But seeing is the only way to believe. Get a demonstration of Datadex at your local Apple dealer. See the personal computing power it can bring to your office and home. If you've looked at a VisiCalc-type program, see Datadex before you buy. By the way, about IUS. We're the Apple of software. We got there by giving you great products and super support. We provide customer service over the phone. Professionally written documentation. And products that are never outdated, only updated. Information Unlimited Software, Incorporated, 281 Arlington Ave. , Berkeley, CA 94707. (415) 525-9452. Datadex is a trademark of Sonnma Softworks. EasyWriter is a trademark of Cap'n Software. Apple is a trademark of Apple Computer Inc. VisiCalc is a trademark of Personal Software, Inc PADDLES Interfacing with Modular Breadboards Roger ] Combs and Paul E Field Department of Chemistry Virginia Polytechnic Institute and State University Blacksburg VA 24061 Often, microcomputer interfacing is a simple task requiring only a basic knowledge of digital electronics. The availability of breadboarding sockets has made building and testing of digital electronics circuits relative- ly easy. (Breadboard sockets considered here are the E & L Instruments SK-10 and the AP Products Super Strip.) The ease of digital-circuit testing with breadboards can be extended to microcomputer interfacing by use of func- tional modules which plug into these breadboards. We call these modules PADDLEs (Peripheral Analog/Digital Device-Logic Extensions). Breadboarding sockets have made building and testing digital elec- tronics relatively simple. The various PADDLE modules perform the following functions: address decoding for device selection, D/A (digital-to-analog) conversion, A/D (analog-to-digital) conversion, displaying data, and debouncing switches. Once you have built these circuits in modular form, you will not have to build them from scratch for every bread- board project, and you will not have to use valuable breadboard space that could otherwise be delegated to the project at hand. It is best to avoid constructing modules so complex that their use becomes cumbersome and their utility limited. For this reason, we shall consider building PADDLEs to perform only those functions which are often called for in digital circuits and which are easily integrated into prototype interface circuitry. We have found a minimum configuration of five PADDLEs most useful both for interfacing projects and for instruction. These consist of (1) a set of three switch- debouncing circuits, (2) a set of eight logic switches hav- ing a latched-pulse output for interrupt generation, (3) a dual seven-segment display, (4) an A/D-D/A converter and comparator for either analog-to-digital or digital-to- analog conversion, and (5) a device decoder capable of generating eight unique outputs from an 8-bit input. A single 8-bit address decoder PADDLE can be used to select devices, provided the microcomputer uses ac- cumulator I/O (input/output). In order to decode a 16-bit memory address, two decoder PADDLEs would be necessary. Though the PADDLEs can be used with other microprocessors, our focus is on the 8080 family. In the following text we consider each of these PADDLEs in terms of function and design. Pulser PADDLE This PADDLE (see figure 1) generates a digital pulse, either positive or negative, that is devoid of the bouncing (momentary intermittent contact) always found in mechanical switches. This is done by the use of an RS (set-reset) flip-flop. Often an RS flip-flop is constructed from two NAND gates; however, the same result can be obtained by the use of two inverters. Either a positive or negative pulse is available at the output of each RS flip- flop. With a single type-7404 hex inverter, three RS flip- flops can be constructed (rather than two using a single 7400 quad NAND gate). The operation of an RS flip-flop constructed from either inverters or NAND gates is controlled by the current-sinking ability of a TTL (transistor-transistor logic) device output, since a floating input connected to an output that is low will also be pulled low. These pulsers are a means of manually generating signals that can be used to enable or clear such devices as monostable multivibrators (one-shots), counters, latches, and so on. Logic Switch PADDLE As the name implies, the device in figure 2 allows definition of a logic 1 or on each of eight parallel lines. A single-pulse switch is also provided to generate an in- terrupt pulse that is latched by a 7474 D-type latch. Each of the eight lines is three-state buffered and enabled by the same external pulse that clears the D latch. Used with an 8080A microprocessor, the output line marked P can be tied to INT (the processor's interrupt line) and the input-enable signal, labeled E, can be connecte d to the microprocessor's interrupt-acknowledge line, INTA. This allows the PADDLE to functio n as an interrupting device. Once INT has been accepted, INTA will gate the instruction defined by the logic switches (usually a special-restart subroutine call, RST X) onto the data bus. 348 April 1981 © BYTE Publications Inc Number Type +5V GND IC1 7404 14 7 £ SW2 _6NC O 0V "L O 0V OOV "L O ov J" OOV "L O>0V J" Figure 1: Schematic of a PADDLE for manually producing bounceless pulses. SW1 thru SW3 are momentary-contact switches; A thru F are sections of a 7404 hex inverter integrated circuit. Octal BOC 377 7.7. 246 4.6 135 3 5. 012 1 2 Table 1: Examples of BOC (binary /octal code) coding using two seven-segment displays and their decimal points to represent an 8-bit number. A short program to test this function using RST 4 is given in listing 1. Alternately, the PADDLE can be used as an input device to the accumulator (by properly using E with device decoding), or E can be tied to ground and the logic switches used as individual switches. Display PADDLE This device (see figure 3) displays an 8-bit word on seven-segment LED (light-emitting diode) displays in either the BCD (binary -coded-decimal) format or a BOC (binary/octal-code) format. The BCD format is actually the hexadecimal display obtained with the 7447 seven- segment decoder. Since the upper six digits of this code are not particularly useful, or at least not easily memo- rized, we have devised the BOC format in order to dis- play an 8-bit word using the two seven-segment displays and their associated decimal points. Number Type + 5V GND IC1 7474 14 7 IC2 74368 16 8 IC3 74368 16 8 GND A N I N N C NORMALLY CLOSED N NORMALLY OPEN * <3 E -O D7 O D6 -O D5 -O D4 0» 03 O D2 O Dl O DO CHERRY MICROSWITCHES Figure 2: This PADDLE circuit permits the sending of 8 bits of data to a processor by functioning as either an interrupt or an input device. Switch C is of the momentary variety, while the eight data switches are SPST (single pole, single throw). Listing 1: Routine to exhibit function of the Logic Switch PADDLE as an interrupt device. An indefinite delay is generated by use of EI (enable interrupts) followed by HLT (halt). Each time an interrupt is generated the display will increment by one. SUB A /CLEAR ACCUMULATOR AGAIN, INR A OUT DISPLAY EI HLT /INTERRUPT IS ENABLED 000 040, POP H /RESTORE STACK POINTER JMP /RST 4 MUST BE JA MMED ON DATA BUS AGAIN /AT TIME OF INTA" IN ORDER TO RETURN PAGE /TO NEW DELAY April 1981 © BYTE Publications Inc 349 + 5V DO O- Dl O D2 C^ D3 O- o- D4 [Z>- D5 \Z>- D6 O D7 [~>- ID 2D 3D IC1 7475 10 2Q 30 4D 15 16 IC2 7475 ID 2D 4D 1Q 20 3Q 30 40 40 DIP PLUG JUMPERS BCD 8 GND 8 GND DIP SOCKET 03 RD Q4 LA Q5 LB 06 LC 06 RP 07 LD Q7 LP BOC LP 16 LD 15 RP 14 GND 13 LC 12 LB 11 LA 10 RD 9 NC -NO CONNECTION Number Type + 5V GND IC1 7475 5 12 IC2 7475 5 12 IC3 7447 16 8 IC4 7447 16 8 Figure 3: Binary data on lines DO thru Dl can be displayed on two seven-segment LED (light-emitting diode) displays in either BCD (binary-coded-decimal) or BOC (binary /octal-code) format (see text) using the Display PADDLE. Resistors Rl thru R16 are 240-ohm Vt W. Binary/octal-code format is binary in the sense that the two most significant bits are displayed on the decimal points, and it is octal since the remaining six bits are displayed as two octal digits on the seven-segment displays. BOC represents a substantial advantage over normal numeric display because only two rather than three displays and decoders are required. Although one could monitor the eight lines using alphanumeric hexa- decimal displays, these are much more expensive than seven-segment displays with decimal points. The ability to use the displays in either a BCD or BOC format is selected by using one of two jumper-wired dual- inline plugs inserted into a 14-pin DIP (dual-inline package) socket. The eight data-input lines, DO thru D7, are brought to a pair of 747 5 qua d D latche s. The outputs of the latches, Q0 thru Q7, Q6, and Q7, are routed via the DIP plug to obtain the selected display format. In either configuration, signals from Q0 thru Q2 bypass the DIP plug and connect directly to the three least signifi- cant inputs of the 7447 decoder-driver for the right-hand display. In the BCD configuration, the DIP plug directs Q3 to the MSB (most significant bit) input of IC3, the right- hand 7447, and Q4 thru Q7 to the appropriate inputs of IC4, the left-hand 7447. The decimal points of the displays are not connected. In the BOC configuration, the DIP plug directs Q3 thru Q5 to I C4, gr oun ds th e MSB inputs of both 7447s, and connects Q7 and Q6 directly to the left- and right-hand decimal points of the FND 507 LED displays. Use of the logical complements of Q6 and Q7 is necessary because the FND 507 is a common-anode display. On the PADDLE module, the gating inputs to the 7475 quad D latches are tied together and labeled E (enable). When E is at logic 1, the data present on lines DO thru D7 is displayed; on the l-to-0 transition it is latched. In this manner the Display PADDLE can be used as an output device (provided proper address decoding is implemented to allow the 7475s to latch the data bus at the correct time). A/D-D/A PADDLE The PADDLE in figure 4 can be used as either an A/D (analog-to-digital) converter or a D/A (digital-to-analog) converter. It consists of the following: a 7404 hex in- verter, two 7475 quad D latches, a 1408L8 8-bit D/A con- verter, a 741 operational amplifier (op amp), and a 311 voltage comparator. Because the latter three devices re- 350 April 1981 © BYTE Publications Inc K5V E O- D7 \Z>- D6 O- D5 O- D4 [3>- D3 O- 02 O- Dl |Z>- DO O- IC1 7475 4D 40 3D 2D ID 30 2Q 1Q 16 10 IC2 7475 4D 3D 2D ID 4Q 30 20 1Q 15 IC6 ^ 74368 ;ik n^ 10 11 12 IC3 RC Vref(-) MC1408L8 Al V REF W A2 A3 A4 A5 A6 A7 A8 COMPEN V EE '0 16 15pF 15 + 5V IK -*wv 2.2K * >680J1 IK _vv/v- vao Figure 4: Analog-to-digital and digital-to-analog conversion of data is performed by the A/D-D/A PADDLE in conjunction with the SAP program in listing 2. V A! and V A0 are the analog input and output lines, respectively. The asterisk indicates the voltage reference point; jumper ] allows generation of negative output voltages. IC 6 is one section of a 74368 integrated circuit. Number Type + 5V GND -12V + 12V IC1 7475 5 12 IC2 7475 5 12 IC3 MC1408L8 13 2 IC4 LM741 4 7 IC5 LM311 1 4 8 IC6 74368 16 8 quire +12 V and —12 V, wire-insertion sockets labeled + V and —V are provided on the PADDLE for connec- tion to an external power supply. Let us fiFst consider the use of this PADDLE as a D/A converter and note its limitations. The PADDLE is designed so that once an 8-bit word is latched by the 7475s, the 1408 D/A converter converts this byte into a proportional current. The 741 operational amplifier con- nected to the output of the D/A converter serves as a current-to-voltage converter. When the jumper shown in figure 4 is not inserted, the D/A converter is in a unipolar mode and can generate voltages between and the positive external power-supply voltage. In the unipolar mode, the voltage range is dependent upon the reference current supplied to the D/A converter and the amplifier feedback resistance at the output of the D/A converter. The calculation of this voltage is based on the digital value of the 8 bits DO thru D7: V AO = v„ R,( DO , Dl D2 , D3 D4 + — + — + — + — 2 4 8 16 32 + D5 64 + D6 128 + D7 256 where R ref is the resistance provided by a 1 k-ohm poten- tiometer and R f is 5.1 K-ohms (from the amplifier feed- back resistor). Note that V ref at the node labeled with the asterisk in figure 4 is determined by the voltage-divider circuit and is calculated to be 1.18 V. As R ref is reduced to zero, the voltage output goes to a minimum value of ap- proximately + 4.0 V. Based on the previous equation, we can infer that an impedance of about 500 ohms exists at pin 14 of the 1408L8. To use the D/A converter in a bipolar mode requires insertion of a jumper on the PADDLE. This jumper con- nection is made between two wire-insertion sockets. It in- troduces an offset current via R that permits negative output voltages to be obtained. Note that R re( as defined can be interpreted as a scaling factor because it approx- imately defines the range of voltage values possible at the output V A o- This only approximately defines the range in the bipolar mode because of the parallel resistance of R in- troduced into the voltage-divider circuit. Because the in- verting input of the operational amplifier is at virtual ground, the resistance from V ref to ground now becomes the 2.2 k-ohms of potentiometer R in parallel with the 680-ohm resistor. Introducing the offset current (V ref /R ) April 1981 © BYTE Publications lnc 351 Number Type + 5V GND IC1 74138 16 8 IC2 7400 14 7 IC3 7404 14 7 A7 O A6 C> A5 O A4 O A3 O A2 £> Al O A0 E> Figure 5: Jumpers located at C allow the 8-Bit Address Decoder PADDLE to decode any eight consecutive addresses out of a possible 256. yields the bipolar voltage: V„,„ / DO Dl AO R„ f V 2 4 8 16 D3 16 D4 32 + D5_ 64 + D6 128 + D7 256 ) v„ R n R, As a result of the reference voltage's dependence on R , both the offset and scaling potentiometers must be adjusted to give a voltage symmetric about V. The resolution of the D/A converter in either unipolar or bipolar mode is one part in 256, or 0.4%. Now let us consider use of the PADDLE as an A/D converter. This is accomplished by using a software routine in conjunction with the D/A converter and the Listing 2: SAP, the successive-approximation program. Also see figure 6. SAP, ADC, SUB A LXIB O00Q 200Q MVID 010Q ORAB MOV C,A OUT DAC IN FLAG ANI 200Q JNZ WAIT PAGE NEXT, WAIT, MOV A,B XRAC MOV C,A MOV A,B RAR MOV B,A MOV A,C DCR D JNZ ADC PAGE RET NOP IMP NEXT PAGE voltage-comparator integrated circuit. The 311 voltage comparator compares the analog input voltage, V AI , to a reference voltage, V AO , supplied by the D/A converter, derived from a program-generated digital input. The selection of inputs to the voltage comparator with V AI at pin 3 and V AO at pin 2 of the LM311 (IC5) is based on impedance matching (ie: pin 2 is a high-impedance input and avoids loading the analog-signal source). Now the two voltages are compared in relative magnitude and the result is reflected in the output (pin 7) of the comparator. If V A1 is greater than V AO the output will be at the negative saturation voltage; conversely, if V AI is less than V AO , the output will be at the positive saturation voltage. Because the LM311 has an open- collector output, the output voltage is made TTL- compatible by adding a pull-up resistor tied to +5 V. The output is tied to D7 of the data bus through a three-state buffer, thus allowing the signal to be monitored by SAP (a successive-approximation pro- gram, given in listing 2, with the flowchart shown in figure 6). A logic state of 1 at D7 indicates that an output byte (ie: V AO ) is too low, while a logic indicates that the byte is too high. SAP starts with the most significant bit and either sets or clears it depending upon the status of D7. This process of setting or clearing successive bits is continued until all 8 bits have been tested. Therefore, if the analog input voltage is constant over the duration of the SAP execu- tion time, it can be measured to within 0.4%. SAP takes eight steps to adjust V AO regardless of the value of V A1 . Thus, the rate of conversion is constant in this particular software version of an A/D converter. Calculating the maximum rate of conversion requires computation of the SAP execution time because each SAP step allows suffi- cient settling time for the D/A converter. 352 April 1981 © BYTE Publications lnc 8-Bit Device Decoder PADDLE This PADDLE uses one 7404 hex inverter, one 7400 quad NAND gate, and a 74138 3-to-8-line decoder (see figure 5). It allows generation of device-select pulses for use in accumulator I/O typical of the 8080 family of microprocessors. As a decoder, the PADDLE provides unique decoding for eight adjacent device codes from XX0 to XX7 over the range of 256 devices. This is done by C SAP ) SUBA I XI B 000Q 200Q MVI D 010Q CLEAR A AND C; PUT TEST PATTERN IN B = 200Q SET D FOR BIT COUNT ■ »10 0RA B MOV C,A OUT DAC IN FLAG ANI 200Q JNZ WAIT PAGE NOP JMP NEXT PAGE SAVE ALL '1' BITS FROM A AND B IN A STORE AS CURRENT VALUE IN C COMPARE CURRENT VALUE TO UNKNOWN yS 1 S >v NO V AI y~ ? / DECREASE CURRENT VALUE: RESET TEST BIT= WAIT EQUAL NUMBER OF CLOCK CYCLES ,1 ' SHIFT TEST BIT TO NEXT LESSER DIGIT FOR NEW B RESTORE A TO CURRENT VALUE B MOV A XRA C MOV C,A MOV A,B RAR MOV 8, A MOV A,C DCR D JNZ ADC PAGE f RETURN J RET Figure 6: A flowchart of SAP, the successive-approximation program of listing 2. The 8080 code is shown with each flowchart step. jumpers in wire-insertion sockets on the PADDLE, which select unique decoding for A7 thru A3 (or A15 thru All) of the address bus lines. Once a device code is generated, it must b e ORed (off of the PA DDLE m o dule) with either I/OR (referred to as IN ) or I/OW ( OUT ) to create_a devi ce-sel ect pulse for input or output, respectively. IN and OUT are ob- tained by NANDing the appropriate l atche d status bit with the control pulses DBIN (input) or WR (output) on an 8080 processor. In terms of the S-100 bus, IN is de- fined as sIN P ( pin 4 6) NANDed with pDBIN (pin 78), while OUT is PWR (pin 77) inverted and NANDed with sOUT (pin 45). Construction Details The printed-circuit layouts for the five PADDLEs are presented in figure 7. Each board is 3 inches long and either IVi or 2 inches wide. The extra section of the Display PADDLE which supports the seven-segment display at a comfortable viewing angle is 1% inches long. The component layouts for the PADDLEs are given in figure 8. Because the layouts are for single-sided copper foil, all jumpers, as well as all other components, were run parallel to the edges of the PADDLE, with none of the jumper wires crossing. Note that the pins for power and ground must be carefully aligned for insertion into the breadboard. The power bus is assumed to be the outer strip on the breadboard. All circuit-board holes were drilled with a #65 drill bit (with the exception of holes for wire-insertion sockets; these required a #55 drill bit). The small switches used for the pulsers required that slots be cut with the wheel-cutter blade of a Dremel tool. Marks are provided on the switch pads for guide holes to be drilled at each end of the slots. It was found convenient to mount the Display, 8-Bit Address Decoder, and A/D-D/A PADDLEs on the side of the breadboard away from the experimenter, while the Logic Switch and Pulser PADDLEs were plugged into the breadboard on the side nearest the experimenter (see photo 1). This accounts for the manner in which the PADDLEs were labeled in figure 7. With this arrangement, switches and pulsers are close at hand and easy to manipulate, while the display is posi- tioned to face the experimenter and the wire-insertion sockets and their associated jumpers are out of the way. Once the circuit boards are etched, drilled, and tin- plated, the following steps provide the most systematic approach for assembly: 1. Spray-paint the component side of the board with enamel. 2. Label component side with transfer letters. 3. Spray labels with clear acrylic coating. 4. Insert wire jumpers; solder and trim leads. 5. Insert resistors; solder and trim leads. 6. Insert and solder IC sockets. 7. Insert and solder potentiometers. 8. Insert capacitors; solder and trim leads. 9. Using either wire-wrap posts or #24 gauge wire, mount breadboard-insertion pins so that they extend 0.3 inches below the board, solder, and trim flush on compo- nent side. 10. Insert and solder wire-insertion sockets. Text continued on page 356 April 1981 © BYTE Publications Inc 353 Pef 1979 o ------ (a) Pulser PADDLE /S&lililHIil o o o © iioiDisioioiEgii &BA (b) Logic Switch PADDLE (c) Display PADDLE c Pef 1979 (d) A/D-D/A PADDLE o (e) 8-Bit Address Decoder PADDLE Figure 7: Full-size printed-circuit-board patterns for the five PADDLEs. 354 April 1981 © BYTE Publications Ire Circle 271 on inquiry card. 1 1 C 10 7404 • *■ E P 7474 " I 74368 74368 a • I,,,, (a) PULSER PADDLE (b) LOGIC SWITCH PADDLE R1-R16 FND507 FND507 M CQ a a □ a / / DIP PLUG 7475 7475 (c) DISPLAY PADDLE 2K IK 680fi IK 2.2K <■© V ©- @ A ©I 120pF 200J1 100 K IK 15pF ©©©©©©©© 7 © © © 74138 7400 7 © © © O G ® <= 3 © 1 ©C ©0 7404 -0 (d) A /D-D/A PADDLE (e) ADDRESS -DECODER PADDLE Figure 8: Component view of the individual PADDLEs. GTC-101 Terminals We're overstocked on these powerful, reliable standard data terminals. The GT-101 is 2-80 based with standard printer port, user-settable clock, 8 user-programmable function keys and much more! Order Today! Limited Quantities. Reg. $999.00 $"7QC Clearance Price Only / t/ D as v CTA ADC-16C 16 Channel variable A-D Board! Can be used for Position / pressure/ Photo- electric/and Temperature Measurements, and as a computerized Volt/Ohm meter. Board is shipped with operating manual, software, and a test conducter. For use with Apple ll/lll. /i-7r>95 introductory Price I / DISPLAY PADDLE £>J E>^ -Odo -Odi -Odz O" -C>D4 -C>D5 -C>C>6 HZ>D7 E D7- DO LOGIC SWITCH PADDLE Figure 9: Configuring three PADDLEs as an I/O (input/ output) device for an 8080-type system requires a single 7402 inverter. O>°SCILL0SC0PE ADDRESS- DECODER PADDLE ^C^ ASO- AiO- A2(I^ A1|Z^ A0(^>- outC^ inO^ -<^AUDIO OSCILLATOR A / D - D /A PADDLE £>U ^E^3Z^ k> c -Q3>D2 -Ow -OD4 HZ>05 -OD6 -0>D7 Figure 10: PADDLE configuration to convert the output of an audio oscillator to digital form and back to analog for display on an oscilloscope. MICROSETTE CASSETTES • ■"■•■ • -■• C-10 C-20 COMPUTER CASSETTES Ai_ C-60 • ■■ • »0 * «■.(.«— ..» vi- 'A L • « ■ • r — "■ Al C4C • "■ • "■ ii., ... oi*« 1 • • £ ., J C-60 C-90 AUDIO CASSETTES Microsette, the undisputed industry leader in short cassettes for micro- computer applications also offers equally high grade audio cassettes at budget prices. Credit card buyers may phone (415) 968-1604. LOOK AT OUR PRICES Length 10 Pack 50 Pack C-10 $ 7.50 $32.50 C-20 $ 9.00 $39.00 C-60 $13.50 $57.50 C-90 $17.50 $77.50 UPS shipment in Cont. USA inch We can not ship to P.O. Boxes Length Qty. Price Total SUBTOTAL Calif. Cust. add Sales Tax TOTAL Check or money order enclosed □ Charge to: Visa □ Master Card □ Account No. Expiration Date SIGNATURE LJ MICROSETTE CO. 475 Ellis Street Mt.View, CA 94043 April 1981 © BYTE Publications Inc 357 META TECHNOLOGIES 26111 Brush Avenue, Euclid Ohio 44132 CALL TOLL FREE 1 -800-321 -3552 TO ORDER IN OHIO, call (216) 289-7500 (COLLECT) FILE BOX DISKETTE STORAGE SYSTEM $24 $29.95 95 for 5 Va" disks . for 8" disks 'RINGS' & THINGS Help prevent data loss and media damage due to improper diskette centering and rotation with the FLOPPY SAVER™ rein- forcing hub ring kit. 7-mil mylar rings in- stall in seconds. Kit is complete with centering tool, pressure ring, 25 adhesive backed hub rings and instructions. HUB RING KIT for 5'/«" diskettes . $10.95 REFILLS (50 Hub Rings) $ 5.95 Protect your expensive disk drives and your valuable diskettes with our diskette drive head cleaning kit. The kit, consisting of a pair of special "diskettes", cleaning solution and instructions, can be used for 52 cleanings. Removes contamination from recording surfaces in seconds without harming drives. CLEANING KIT for 5 1 /." drives $24.95 Single Sided, Soft-Sectored 5'/i-inch, (for TRS-80™) Mini-floppy DISKETTES $21 MTC brings you the ULTIMATE diskette storage system, at an affordable price. Stor- ing 50 to 60 diskettes, this durable, smoke- colored acrylic unit provides easy access through the use of index dividers and ad- justable tabs. Unique lid design provides dust-free protection and doubles as a carry- ing handle. PLASTIC LIBRARY CASES (not shown) An economical form of storage for 10 to 15 diskettes, and is suitable for your bookshelf! Case opens into a vertical holder for easy ac- cess. 5'/4-inch diskette case $3.50 8-inch diskette case $3.95 MICROPARAPHERNALIA DISKETTES (box of ten) 5V4" PLAIN JANE™ $21.95 5!/<" DATALIFE™ MD 525-01 . . $26.95 8" DATALIFE™ FD34-1000 .... $33.95 8" DATALIFE™ FD34-8000 .... $43.95 NEWDOS by APPARAT NEWDOS/80 • SPECIAL $129.95 NEWDOS + to NEWDOS/80 UPGRADE CALL NEWDOS + with ALL UTILITIES 35-track $69.95 40-track $79.95 BOOKS TRS-80™ DISK AND OTHER MYSTERIES . . $19.95 MICROSOFT™ BASIC DECODED $29.95 1001 THINGS TO DO WITH YOUR PERSONAL COMPUTER .... $ 7.95 Let Your TRS-80™ Test Itself With THE FLOPPY DOCTOR & MEMORY DIAGNOSTIC by THE MICRO CLINIC A complete checkup for your Model I. THE FLOPPY DOCTOR completely checks every sec- tor of 35- or 40-track disk drives. Tests motor speed, head positioning, controller functions, status bits and provides complete error logging. THE MEMORY DIAGNOSTIC checks for proper write/read, refresh, executability and exclusivity of all address locations. Includes both diagnostics and complete instruction manual. SYSTEM DIAGNOSTICS $19.95 An improved version of the SYSTEM DIAGNOSTICS above. Designed for single or double density, 35-, 40-, 77-, or 80- track disk drives. Includes new and modified tests. Features THE FLOPPY DOCTOR, Version 3.0. SYSTEM DIAGN0STICS-V3. 95 box of 10 These are factory fresh, absolutely first quality (no seconds!) mini-floppies. They are complete with envelopes, labels and write- protect tabs in a shrink-wrapped box. PLAIN JANE™ DISKETTES The Beautiful Floppy with the Magnetic Personality™ Thousands of people have switched to this low-cost alternative. These quality diskettes are packaged in a plain white box ... no fan- cy printing, fancy names or fancy labels, not even our own (labels cost money). Trust us. PLAIN JANE™ Diskettes $21.95 lOboxesoflO (eachbox)$21.50 VERBATIM'S PREMIUM DISKETTES AT AFFORDABLE PRICES DATALIFE™ Seven data-shielding improvements mean greater durability and longer data life. These individually, 100% error-free cer- tified diskettes feature thicker oxide coating, longer-lasting lubricant, improved liner, superior polishing and more! Meets or exceeds IBM, Shugart, ANSI, ECMA and ISO standards. Reinforcing HUB RINGS help prevent data loss and media damage, reducing errors. Buy the best ... buy DATALIFE™. VERBATIM DATALIFE™ DISKETTES 5'/>-inch (box of 10) MD525-01 $26.95 10 boxes of 10 (each box)$25.95 8-inch FLOPPIES Single-Density, FD34-1000 . . $33.95 Double-Density, FD34-8000 . $43.95 TRS-80 is a trademark of the Radio Shack Division of Tandy Corporation. DATALIFE is a trademark of VERBATIM. PLAIN JANE, AIDS I. AIDS III. CALCS III, CALCSIV, MERGE III are trademarks of MTC. - 1981 by Metatechnologtes Corporation, Inc. MOST ORDERS SHIPPED WITHIN ONE BUSINESS DAY Products damaged in transit will be exchanged. PRICES IN EFFECT April 1, 1981 THRU April 30, 1981, Prices, Specificiations, and Offerings subject to change without notice. WE ACCEPT • VISA • MASTER CHARGE • CHECKS • MONEY ORDERS • COD. 358 BYTE April 1981 Circle 273 on inquiry card. What's New? PUBLICATIONS UPTREND UPTREND is written and designed to help owners of Personal Software's programs increase their productivity. It includes how-to articles on program usage, questions and answers, infor- mation on the programs themselves, and letters and interviews with pro- gram users. The publication is sent to owners of Personal Software's pro- grams, and it is available at computer retail stores selling the company's products. Contact Personal Software Inc. 1330 Bordeaux Dr, Sunnyvale CA 94086, (408) 745-784 1 . Circle 400 on inquiry card 1 980 APL Users Meeting Proceedings The proceedings of the October 1 980 APL users meeting are available from I P Sharp Associates. The book is comprised of 52 papers read at the meeting. The subjects covered are APL resources, APL for financial ap- plications and economic forecasting, international networks, personnel- and record-handling systems, in- house APL timesharing services, APL techniques and programming tools, teaching APL, and more. The price is S 1 8 per copy. Contact I P Sharp Asso- ciates Ltd, Publications Department, 145 King St W, Toronto, M5H 1J8, Canada, (416) 364-5361. In the US, address I P Sharp Associates Inc. 1 200 First Federal Plz, Rochester NY 1 46 1 4, (716) 546-7270. Circle 401 on inquiry card Music and Microprocessors Hal Chamberlin's Musical Applica- tions of Microprocessors provides coverage of digital microprocessor- sound and music synthesis. This book discusses linear techniques for micro- processor applications, musical appli- cations for 1 6-bit microprocessors, and all phases of waveform shaping and filtering. Waveform charts, nomographs, and sample control and generation programs written in BASIC are provided to inspire experimenta- tion and application. It is published by Hayden Book Company Inc. 50 Essex St, Rochelle Park NJ 07662, (201) 843-0550. The cost is S24.95. Circle 402 on inquiry card H H Smith Catalog H H Smith Inc, a manufacturer of electronic components and hard- ware, has published Catalog 810 for design engineers and purchasing agents. Printed-circuit board supports, cable clamps, and spacers are among the items featured. Contact H H Smith Inc, 812 Snediker Ave, Brooklyn NY I 1207, (212) 272-9400. Circle 403 on inquiry card Micro Media Magazine This bimonthly magazine provides software reviews, graphic art, adver- tisements, articles, and more for the Heath H-8, -88, -89, and Zenith Z89 computers. The magazine comes in an interesting format: on a floppy disk. Subscriptions are $ I 1 .95 for a single issue and S55 for a year. Micro Media supports its subscribers by making the magazine available in both Benton Harbor and Microsoft BASIC, as well as HDOS or CP/M disk formats. Contact Micro Media at POB 402286, Garland TX 75040, (800) 527-4830, ext 101; in Texas (800) 442-4884, ext 101. Circle 404 on inquiry card TRS-80 Users Software Mews CIE People's Software News is free to TRS-80 users. The publication has news of the activities at People's Software, where public-domain soft- ware is distributed for a copying charge. The price for a cassette of pro- grams is $10.95. The current 5-tape library contains 206 programs, for $54.75. Contact the Computer Infor- mation Exchange Inc, POB 159, San Luis Rey CA 92068, |714) 757-4849. Circle 405 on inquiry card H-8 Programming for Beginners This book, written by Don Inman, Ron Santore, and Bob Albrecht, is de- signed for Heathkit H-8 users. Com- puter terms are defined for beginners, and each chapter tests the reader's knowledge by challenging him or her to write a short program or subrou- tine. The book is a short program- ming course that explains assembly language and serves as an introduc- tion to Benton-Harbor BASIC. It is available for $8.95 from the Dilithium Press, 30 N W 23rd PI, Portland OR 97210, (503) 243-1 160. Circle 406 on inquiry card Software Buyer's Guide The Official Software Buyer's Guide is published each January and July. It contains listings of software for business applications, word pro- cessing, operating systems, games, and general programs for many microcomputers. For information on space deadlines, advertising rates, and availability, contact OSBG, List- ing Department, POB 18278, Reno NV8951 1, (702) 356-8400. Circle 407 on inquiry card Where Do New Products Items Come From? The information printed in the new products pages of BYTE is obtained from "new product" or "press release" copy sent by the promoters of new products. If in our judgment the information might be of interest to the personal computing ex- perimenters and homebrewers who read BYTE, we print it in some form. We openly solicit releases and photos from manufacturers and suppliers to this marketplace. The information is printed more or less as a first-in first-out queue, subject to occasional priority modifications. While we would not knowingly print untrue or inaccurate data, or data from unreliable companies, our capacity to evaluate the products and companies appearing in the "What's New?" feature is necessarily limited. We therefore cannot be responsible for product quality or company performance. April 1981 © BYTE Publications Inc 359 What's New? SYSTEMS Small Business System from Systel The REPORT/80 is a portable busi- ness system for less than 510,000. It combines the 8085 and Z80 micro- processors. 64 K bytes of memory, a keyboard; a 12-inch, 80-column by 25-line video display, two 5-inch floppy-disk drives, a 9 by 7 dot-matrix printer, and two RS-232C serial ports in a single unit. CP/M is included. Systel offers a selection of business programs as an option. The Model 1 1 has a suggested retail price of $8950, and includes two double-sided, double-density drives. The Model 15 has two double-sided, guad-density drives, and costs $9950. For more in- formation, contact Systel Computers Inc. 20370 Town Center Ln, Cuper- tino CA 95014, (408) 253-0992. Circle 408 on inquiry card 6800/6809 Development Systems Can Offer 2-Megabyte Storage The Scoutsystem development sys- tems from SSB (Smoke Signal Broad- casting) are for 6800/6809 micropro- cessors. They provide 2 megabytes of floppy-disk storage and up to 64 K bytes of programmable mem- ory. The series features a video dis- play, dual 5- or 8-inch disk drives, plus SSB's Hunter debugging package, which allows memory, register, and stack contents to be inspected and changed. Software includes a macro- assembler that provides relocatable code. An MDOS conversion package permits files generated under it to be read by SSB's DOS68 or DOS69 and vice versa. A text editor and text pro- cessor are available. The EPROM (erasable programmable read-only memory) programmer can handle 1 K-, 2 K-, or 4 K-byte EPROM s. An optional in-circuit emulator allows the host system to be tied into the target system. The Scoutsystem series also contains a diagnostic routine for iden- tifying failed integrated circuits. Prices for the Scoutsystem series range from under $5700 to $7745. Contact Smoke Signal Broadcasting, 31336 Via Colinas, Westlake Village CA 91362,(213)889-9340. Circle 409 on inquiry card Systems from Zeda The 520 series of portable micro- computers feature a Z80A micropro- cessor, a video display, floppy-disk drive, and detachable keyboard. The series can be powered by standard 1 1 VAC current, 1 2 VDC, or op- tional internal batteries. You can order your system with either a 5-, 9-, or 12-inch video screen (ie: the Models 525, 529, or 522, respec- tively). The series has 48 K bytes of programmable memory, 2 K bytes of video programmable memory, a double-density floppy-disk-drive con- troller, and a 200 K-byte drive. A 400 K-byte guad-density drive is avail- able. Up to three drives can be added to the system. A Centronics printer port, an RS-232C serial port, and a bar-code-reader port for a Hewlett- Packard HEDS-3000 digital wand are provided. The CP/M-compatible ZEDOS operating system has all the CP/M and CDOS + system calls, plus ZEDOS calls. A status line displays a program counter; disk-error informa- tion; a low-power indicator; a type- ahead buffer; system idle, screen frozen, and printer activated flags; and disk status. The prices are $4495 for the 522, $3995 for the 525, and $4195 for the 529. Contact Zeda Computers International Ltd, 1 662 W 820 North, Provo UT 84601, (801) 377-9948. Circle 410 on inquiry card 6809 Board for the Apple II The Mill is a 6809 microprocessor board that plugs into the Apple II. It can be used in manufacturing or labo- ratory process-control monitoring and concurrent programming tasks. Users can run existing 6502 programs, 6809 programs, or any software reassembled for the 6809 from ex- isting 6800 source code. In operation, the 6809 and 6502 run concurrently, with the 6809 acting as the bus master during the 6502 's bus ac- cesses. Typically, the 6809 com- mands 80% of the available bus time for memory accesses and data trans- fers. The 6502 can stop the 6809 for time-critical I/O operations. Sections of 6502 programs can be recoded into 6809 machine language. The FLEX operating system can be employed with the Mill. The Mill features directly addressable stacks and the position independence of code, and it allows the Apple II to be used in a multipro- gramming mode. The Mill is available from Stellation Two, POB 2342, Santa Barbara CA 93 1 20, for $275. Circle 411 on inquiry card 1 6 Megabytes of Storage on the QT QT System + can be used for ac- counting, word-processing, and scientific applications. It features a Z80 microprocessor, two 8-inch floppy- disk drives, a controller for double- sided, double-density 5- and 8-inch drives, and a Televideo 920C video terminal. There are 48 K bytes of dy- namic programmable memory (ex- pandable to 64 K bytes), a 2 K-byte monitor program and Disk BIOS (Basic I/O Subsystem) on an EPROM, two RS-232C ports, two parallel ports, a real-time clock, and the CP/M 2.2 or the MP/M operating systems. The QT System + comes in two versions. The I -megabyte, single- sided, double-density system sells for $4295. The 2-megabyte, double- sided, double-density unit is priced at $4995. For complete details, contact QT Computer Systems Inc. 1 5620 S Inglewood Ave, Lawndale CA 90260, (800) 421-5150; in California (213) 970-0952. Circle 412 on inquiry card 360 April 1981 © BYTE Publications Inc What's New? PERIPHERALS Voice-Entry Terminal for the Apple II The VET/2 voice-entry terminal plugs into any slot of a 48 K-byte Apple II. A direct keyboard link allows the user to choose keyboard or voice input at any time. Once a word has been entered into the program, whenever it is spoken, the function is performed. The VET/2 is supplied with preprocessor, interface board, software with demonstration pro- grams, noise-canceling headset microphone, and a user's manual. The price is S895 from Scott In- struments, 815 N Elm, Denton TX 76201, (817) 387-9514. Circle 413 on inquiry card Connect Your Selectric to a Computer The Escon interface system in- cludes all the electronics, connectors, and instructions necessary to convert an IBM Selectric typewriter into an output printer. Units have been de- signed for S-100 systems, and RS- 232C serial, parallel, and IEEE-488 in- terfaces. No drilling or modification is reguired. The typewriter can still be used in a normal fashion, and its eligi- bility for IBM warranty and service will not be affected. Printing speed is 1 5 cps (characters per second), which is approximately 160 words per min- ute. Prices range from S595 to S675. For details, contact Ipex International Inc. 16140 Valerio St, Van Nuys CA 91406, (213) 781-0020. Floppy-Disk Drives from Commodore The 8060 series of 8-inch floppy- disk drives includes the CBM 8062, which can store 3.2 megabytes of data, and the CBM 8061, which handles up to 1.6 megabytes. The 806 1 reads and writes one side of the disk, while the 8062 handles both sides. The drives and operating sys- tem are compatible with the IBM 3740 format and Commodore's other drives. For more information, contact Commodore Business Machines Inc. 950 Rittenhouse Rd, Norristown PA 19403, (215) 666-7950. Circle 415 on inquiry card Circle 414 on inquiry card Video Terminal from Perkln-Elmer The Perkin-Elmer Model 550S is a block mode/editing video-display unit. Three modes allow for conversational timesharing, transaction processing, and test manipulation or software de- velopment. The 550S offers an op- tional second page of scrolling mem- ory. The 24-line screen windows into 48 lines by 80 columns of text. The standard keyboard has 83 keys, in- cluding a numeric pad and four pro- gram function keys. A serial printer port is standard, as well as automatic on/off host control over terminal block transmissions and half intensity, blink, nondisplay, and protected fea- tures. Transmission types included are: send all, send unprotected only, send line, send page, and send from home to stop code. The 550S is priced at SI 1 89. Contact Perkin-Elmer, Ter- minals Division, 360 Rt 206 South, Flanders NJ 07836, (201) 229-6800. Circle 416 on inquiry card Pitch Analyzer for Speech Synthesis The Visi-Pitch extracts and mea- sures vocal pitch in real time. The de- vice provides visual or numerical de- scriptions of pitch variability, speech rhythm, and intonation contours. It can be used in the testing of speech synthesis and recognition systems, and in speech therapy. The Visi-Pitch interface can transfer frequency or period information to 8-bit parallel in- puts. The period data is generated after each pitch period, and frequen- cy data is generated every 0.5 sec- onds. The data output is 3-state 8-bit parallel. The price for the unit is S2410 from Kay Elemetrics Corpora- tion, 1 2 Maple Ave, Pine Brook NJ 07058. (201) 227-2000. Circle 417 on inquiry card 1 6 K-Byte Memory Card for the Apple II RAMCard provides the Apple II 48 K computer with 16 K bytes of programmable memory. It's compati- ble with Microsoft's SoftCard. It can be used with all software available for the SoftCard, but it cannot be used in addition to the Apple Language Card. The price of the RAMCard is $195. For more details, contact Microsoft Consumer Products, 400 108th Ave NE, Suite 200, Bellevue WA 98004, (206) 454-1315. Circle 418 on inquiry card April 1981 © BYTE Publications Inc 361 What's New? PERIPHERALS Vldeodlsk-to- Apple Interface TheColoney VAI-1 interface board fits inside the Apple and allows com- plete control of the DiscoVision indus- trial videodisk player. In addition, the package provides circuitry to switch computer- or disk-generated video on a single television monitor. The pack- ages sells for S525, and includes a manual, a controller card, junction box for video connections, control subroutines in assembly language and Pascal, cables, and a demonstra- tion program. For additional informa- tion, contact Coloney Productions, 1 248 Blountstown Hwy, Tallahassee FL 32304, (904) 575-0691. Circle 419 on inquiry card Microcomputer- Compatible Temperature Probes Tempsens provides direct temperature input for a variety of microcomputers, including the PET, the Apple II, and the TRS-80. Oper- ating within a temperature range of -24°C to 72°C (-10°F to + I60°F), each Tempsens module provides two temperature probes to the CmC (Con- necticut microcomputer) AIM 1 6 analog input module using a CmC MANMODI. The MANMODl will accept input from up to 8 Tempsens modules, for a total of 1 6 individual probes. The suggested retail price of a 2-probe Tempsens is $49.95. Contact Connecticut microcomputer Inc, 34 Del Mar Dr. Brookfield CT 06804, (203) 775-4595. Circle 420 on inquiry card Light Pen for OSI Computers The L C S Light Pen Kit designed for OSI (Ohio Scientific) computers features a coiled cord and an easily disconnected plug. The light pen is manufactured by Lewis Computer Systems, and is distributed by Faragher Associates Inc, 7635 W Bluemound Rd, Milwaukee Wl 532 1 3, (800) 558-0870. The sug- gested list price is $29.95. Circle 421 on inquiry card Color-Graphics Board for Heath Microcomputers The HA-8-3 color-graphics board can be used with the Heath H-8 and All-in-One computers. The board uses a TI-99 1 8 color video-display-genera- tor integrated circuit. An AY-3-8910 programmable sound-generator cir- cuit is also included. Four X,Y joystick consoles can be used with the board; each console has 4 bits of parallel I/O. A socket is provided for an AMD- 95 1 1 arithmetic processor circuit. The HA-8-3 can be used with most video monitors as well as other video acces- sories utilizing NTSC composite color video. Demonstration software on a 5-inch floppy disk is included. The board sells for $395. Contact Heath Company, Department 350-590, Benton Harbor Ml 49022, (616) 982-3210. Circle 422 on inquiry card 362 April 1981 © BYTE Publications Inc This Black-Hole Diode Is User-Transparent INPUT [~_>- -©- - B.01 2N1B48A 8.08 2N1849 9.52 2N1B49A 9.59 2N1B50A11.01 2N1B50A11.09 2N1890 9.04 2N1893 .45 2N1990 3.92 2n1991 7.36 2N2060 5.03 2N20B0A 4.26 2N2102 1.50 2N2180 1.60 2N2193 .76 2N221B .66 2N221BA 60 2N221S .66 2N2219A .SB 2N2221 .40 2N2221A .42 2N2222 .40 2N2222A 42 2N2223 2N2223A 2N2270 2N2297 2N2322 2N2323 2N2324 2N2325 2N2326 2N2327 2N2328 10.12 2N2329 13.33 2N2368 1.74 2N2369 .42 2N2369A 45 2N2405 2.86 2N2453 439 2*N2463A 4.62 2N2475 .60 2N2478 .60 2N2480 3.59 2N24BOA 3.86 2N2481 .73 2N2483 .39 2N2484 .45 2N2501 8.78 4.26 2.00 2.29 2.80 3.62 5.13 6.66 8.16 3.33 3.19 2.93 3.99 3.72 3.33 4.12 3 B6 B.05 1.80 3.19 286 2N2540 7.7B 2N2573 651 2N2S74 655 2N2575 7.99 2N2676 848 2N2577 10.09 2N2678 10.66 2N2579 12.46 2N2604 1.66 2N2605 .90 2N260B 180 2N2639 2N2640 2N2B41 2N2642 2N2843 2N2644 2N2646 2N2647 2N2652 3.B6 2N26G2A 4.79 2N26B7 2.B7 2N2688 3.33 2N26B9 7.04 2N2690 8.86 2N2713 .16 2N2720 4.52 2N2722 3.99 2N2723 2N2723 2N2785 2N2B00 2N2B57 2N2B94 2N2895 2N2896 2N2S97 2N2903 2N2903A 2N2904 2N2904A 2N2905 2N2906A 2N2906 2N2906A 2N2907 2N2907A 2N2913 2N2914 2N2915 2N2916 2N2917 2N2918 2N2919 2N2920 2M2924 2N2925 2N2944 2N2945 4,06 2N2946 4.59 2N2947 2691 2N2959 4.72 2N3009 2.99 2N3011 1.66 2N3012 2N3013 2N3014 2.06 2N3019 .75 2N3020 6.0S 2PJ3043 40.00 2N3044 34.00 2N3045 28.00 2N3046 37.00 2N3047 31.00 2N3048 28.00 2N3053 .48 2N30&3A 1.73 2N30S4 .90 2N3054A 1.69 2N3055 1.10 2N3055A 1.98 2N3073 1.40 2N3114 9.11 2N3133 7.52 2N3135 7.91 2N3137 3.02 2N3227 432 2N3244 23.87 2N3245 23.87 2N3249 7.58 2N3250 .70 2N32G0A .80 2N3251 .70 2N3261A .75 2N3252 2.06 2N3253 2.40 2N3297 55.10 2N3299 1.30 2N3300 1.66 2N3301 130 2N3202 1.70 2N3303 21.50 2N3307 16.70 2N3308 14.20 2N3330 1.30 2N3375 19.00 2N3390 .26 2N3391A .25 2N3414 .22 2N3416 .25 2N3425 4.50 2 N 3436 2N3437 2 N 3438 2N3439 2N3440 2N3441 2N3442 2N3444 18.20 2N3446 6.80 2N344S 2N3447 2N3448 2 N 3467 2N346B 2N3485 2N3485A 8.60 2N3486 9.60 2N3486A 10.50 2N3494 14.80 2N349S 19.30 3.33 3.72 10.64 6.59 4.66 6.32 6.59 6.99 4.32 2.73 1.90 2.00 1.40 2.10 630 7.40 7.90 3.70 3.80 8.20 2N3793 2N3796 2N3797 2N3798 2M3799 2N3B06 2N3B07 2N3808 2N3B09 2N3810 2N3B11 2N3811A 13.60 2N3B12 27.40 2N3813 27.40 2N3814 29.40 2N3816 31.00 2N381B 36.50 2N3B18A 43.10 2N3B17 43.10 2N3817A36.10 4.90 4.90 6.00 5.40 4.12 5.90 6.12 6.70 PREMIUM QUALITY 3.70 1.60 2.40 2.50 3.70 4.30 5.00 6.00 2.10 2.10 2N3496 15.70 2N3497 20.40 2N3498 9.40 2N3499 10.60 2 N 3500 16.00 2N3501 17.90 2N3506 17.70 2N3507 20.00 2N350B 8.60 2N3509 8.60 2N3510 1.90 2N3511 2.60 2N3546 2N3553 2N3563 2N3564 2N3565 2N3566 2N3567 2N3568 2N3569 2N35B3 2N3584 2N3585 2N3632 24.00 2N3B34 20.02 2N3636 21.95 2N3636 24.20 2N3637 21.80 2N363B .25 2N3638A .26 2N3640 .26 2N3642 .20 2N3643 .35 2N3646 .25 2N3647 2N3646 2N366B 2N3669 2N3670 10.20 2N3677 3.B0 2N36B7 2N3693 2N3694 2N3700 2M3702 2N3703 2N3704 .20 2N3706 .20 2N3706 .20 2N3707 .19 2N370B .19 2N3709 .19 2N3710 .19 2N3711 .19 2N3712 3.90 2N3713 1.80 2N3714 1.90 2N3715 1.80 2N3716 1.90 2N3719 7.10 2N3720 9.80 2N3721 .20 2N3724 .90 2N3725 1.46 2N3725A 1.68 2N3726 2N3727 2N3731 2N3734 2N3735 2N3736 2N3737 2N373B 2N3739 2N3740 2N3741 2N3742 2N3743 19.80 2N3762 8.0S 2N3763 16.50 2N3764 8.06 2N3765 16.50 2N3766 2.00 2N3767 2.30 2N3771 2.40 2N3772 2.50 2N3773 3.60 2N3789 1.B0 2N3790 1.80 2N3791 1.70 2N3792 1.80 9.98 5.30 3.60 3.26 6.46 7.00 7.00 2.20 2.70 2.20 2.00 19.80 1.06 2N3B19 2N3821 2M3B22 2N3923 2N3B24 1.20 2N3B26 23 2N3827 .19 2N383B 22.30 2 N 3839 2.25 2N3843 .60 2N3B59 .25 2N3B60 .20 2N3866 1.54 2N3866A 2.00 2N3867 1.80 2N3868 1.90 2N3870 5.00 2N3B71 6.30 2N3872 8.00 2N3B73 10.10 2N3877A .25 2N389B 2N3B97 2N3898 2N3B99 2N3903 .30 2N3904 .19 2N3905 .20 2N3906 .20 2N3909 1.33 2N3926 20.40 2N3927 21. BO 2N3933 1.60 2N3946 3.90 2N3947 3.60 2N394B 2.70 2N39SO 39.10 2N3957 2.55 2N3959 4.90 2N3960 5.80 2N3962 .51 2N3963 .67 2N3964 .68 2N3966 .6B 2N3968 2N3970 2N3971 2N3972 2N3980 2N3993 2N3994 2N4013 2N4014 2N4016 2N401B 2N4030 .69 2N4031 .76 2N4032 .81 2N4033 1.40 2N4036 .66 2N4037 .60 2N4068 .19 2N4O60 .20 2N4061 .19 2N4062 .19 2N4072 2 30 2N4091 1.14 2N4092 1.07 2N4093 1.05 2N4117 2,20 2N4117A 1.60 2N4118 1.90 2N4118A 1.50 2N4119 1.80 2N4119A 1.60 2N4123 .19 2N4124 .19 2N4125 .20 2N4126 .26 2N4141 .20 2N4142 .20 2N4143 .20 2N4167 2N41B8 2N41B9 2N4167 3.20 1.30 1.20 1.20 4.20 2. BO 2.90 2.70 2.80 10.12 6.36 6.44 6.70 636 2N4169 2N4170 2N4171 10.30 fl.30 6.35 6.60 2N4174 2N41B3 2M4184 2N4186 2N4186 2N41B7 2N418S 2N4189 2N4190 2N4199 6B.20 2N4200 35.20 2N4201 118.40 2N4202 162 50 2N4203 178.20 2N4204 208.00 2N4208 3.90 2N4209 2N4212 2N4213 2N4214 2N421B 2N4216 2N4217 2N421B 2N4219 2N4220 2N4220A 1.50 2N4221 1.60 2N4221A 1.64 2N4222 1.60 2N4222A 1.64 2N4223 1.5B 2N4224 1.50 2N422B .40 2N4231A 1.60 2N4232A 1.90 2N4233A 2.35 .2N4234 1.50 2N4235 1.65 7.10 7.55 850 10.30 4.80 2.10 2,60 290 3.80 5.00 5.70 8.30 12.40 1.40 2N485BA 1.94 2N4859 1.81 2N4860 1.81 2N4860A 1.90 2N48G1 1.90 2N4870 .94 2N4871 .84 2N4878 2N4890 2N4895 2N4895 2N4B97 2N489B 2N4899 2N4900 2N4901 2N4902 2N4903 2N4904 2N490G 2N490B 2N4912 2N4913 2N4914 2N4915 2N4918 2N4919 2N4920 2N4921 2N4922 2N4923 2M4924 2N4925 2N4926 2N4927 2N4928 2N4929 2 N 40 ISO 2N4931 2.38 1.14 2.10 2.80 3.10 .30 3.00 1.26 2N4236 1.80 2N4237 1.35 2N4238 1.50 2N4239 1.BO 2N4240 2.50 2N4248 .25 2N4249 .20 2N4250 .25 2N4256 .20 2N4258 .36 2N4260 19 80 2N4261 23.20 2N4264 .66 2N4265 .72 2N4289 2N4339 2N4340 2N4341 1.50 2N4342 .76 2N4347 1.65 2N4348 2N4361 2N4352 2N4356 2N4358 2N4360 2N4391 2N4392 2N4393 2N4395 2N4398 4.40 2N4399 5.90 2N44O0 .20 2N4401 .20 2N4402 .20 2N4403 .20 2N4404 13.20 2N4405 14.30 2N4406 17.90 2N4407 20.35 2N4409 .31 2N4410 .36 2N4416 1.46 2N4416A 1.64 2N4425 .45 .2N4427 1.50 2N442B 2.70 2N4440 23.25 2N4441 2.07 2N4442 2N4444 2N4449 2N4453 2N4851 2N4852 2N4853 2N4854 2N4855 2N4858 2N4856A 1 .40 2N4857 1.33 2N4857A 1,40 2N4868 1.30 2.23 4.77 6.0B 3.72 1.31 1.31 2.87 5.70 5.45 1.33 3.78 3.00 1.10 1.48 3.19 4.60 3.90 3.48 4.46 4.96 4.33 3.46 2N4937 11. B0 2N4938 4.02 2N4939 3.64 2N4940 22.00 2N4941 24.30 2N4942 21.70 2N4948 1.18 2N4949 3.07 2N4957 5.31 2N495B 2N4959 2N4983 2N49B4 1.50 2N49B7 .75 2N498B 1.20 2N4989 1.60 2N4991 .75 2N4993 1.80 2N4994 .30 2N5016 24.40 2N5022 1.40 2N5023 2N5032 2N503B 2N5039 2N5060 2N5051 2N5052 2N50G8 2NG059 2N5060 .59 2N5061 .60 2N5062 .69 2N6063 .73 2N50B4 .84 2N50B7 1.5B 2N50B8 1.79 2N5069 1.98 2N5070 24.40 2N5071 27.50 2N6086 .19 2N50B7 .19 2N5088 .19 2N50B9 .19 2N5090 18.30 2N5105 2.60 2N5108 4.60 2N5109 .40 2N5131 .25 2N5132 .20 2N5133 .20 2N6134 .26 2N5135 .20 2N5146 28.10 2N5160 4.B0 2N5161 16.04 2N6162 23.71 .2N5164 3.80 2N5165 2N5166 2N6167 2N516B 4.31 2N6169 4.74 4.18 5.60 7.26 1.40 STORES 00 NOT ACCEPT MAIL ORDERS MAILORDER P.O. BOX2208Y CULVER CITY, CA90230 PHONE ORDERS (213) 641-4064 Minimum Older SI 00 Add S2 00 io cover postage and handling Masie' Charge oral VISA welcomed Please include »Qi» charge card number, interbank number and eipirahon dale Some itenu are iubrecl lo piiw sale Mot responsible lor typos Store pricing may vary ham Mail Order puong We reserve the right to subsMute manufacture! 2N6170 2NG171 2N6172 2NE179 2NG190 2N5191 2N5192 2N6193 2N6194 2N6195 2N5198 2N620B 2N6209 2N6210 2N6219 2NG220 2N5221 2NB222 2NG223 2M6224 2N5225 2W5226 2N6227 2N5228 2N5229 2N5230 2N5231 2IM6232 .35 2NG232A 26 2M&241 17.82 2N5246 .72 2N6265 2N6266 2N6267 2NG268 2 N 5269 2M5270 2N6271 2N6294 2N529B 2NG301 2N5302 2N6303 2N5306 2N&308 2N6309 2NG320 2N5321 2NG322 2N5323 2NG336 2N5337 2N5338 4.60 2N6339 5.10 2N5344 10.40 2N5346 12.60 2IM5346 22.70 2N5347 25.70 2N5348 26.70 2N5349 32.60 2N6354 .40 2N5355 .40 2N53G9 2N5359 2N5360 2N5361 2N5362 2N5363 2N5364 2N5366 2N5367 2N536B 2N53B9 2N5397 2N5398 2 N 6400 2 N 5401 2N5415 2N5416 2N5418 2N5419 2N5420 2N5427 2N5428 2N5429 2 N 5430 2N5431 2N5441 2 N 5442 2 N 5443 2 N 5444 2 N 5445 2N544G 2N5447 4.52 5.39 6.44 3.60 307 3.88 3.60 2.21 2.16 2.16 2.02 2.15 2.16 2,78 1.80 2.49 1.07 18.00 1.60 2NS44B 2N6449 2N64B0 2N5461 2N5453 2N6457 2N545B 2N6469 2N6480 2N5461 2N5462 2N54B3 2N5464 2N6466 2N54B4 2 N 5485 2N6488 2 N 5490 2N5660 2N6551 2N6656 2N5835 2146636 2N6837 2060 2N6838 .70 2NG639 .63 2N6640 .70 2N5641 12.20 2 N 5642 14.60 2N5643 20.60 2N6645 1840 2N5646 27.60 2N5863 .67 2N66&4 63 2N566B 82 2N6669 .76 2N5670 .82 2N5871 10.50 2N6872 12.60 2N6769 .24 2N5770 .23 2N6772 .24 2N6777 .90 2N577B .90 2N6781 1.B5 2N6782 2N5783 2N6784 2N6786 1.35 2N5786 1.35 2N5817 .40 2N5822 .60 2N5824 .25 2N5B27 .30 2N582B 40 2N5828A 40 2 N 5830 .27 2N5831 .27 2N5835 3.86 2N5B36 4 60 2N5837 540 2N5B41 13.80 2N5842 11.60 2N5847 18.50 2N5848 20.60 2N6849 27.60 2NG862 76.50 2N5B75 135 2N5B76 1.47 2N6877 1.36 2N6B78 1.65 2N6941 30. BO 2N6944 12.30 2N6945 15.30 2N6946 19.30 2N6947 12.30 2N5961 .19 2 N 6974 2N5975 2N5976 2N6977 2N6978 2N5979 2N5980 2N5981 2N5982 2N59B3 2N5984 2 N 6985 2N59B6 2NG987 2N5988 2N59B9 2.71 3.05 3 60 2.48 2.80 3.30 3.40 3.90 4.70 2.60 2.90 3.60 3.70 4.10 4.50 3.50 2N6990 3.90 2N5991 4.30 2N6004 .70 2N6014 .70 2N6027 .60 2N6028 .60 2N6029 6.94 2N6030 7.30 2N6031 B.40 2N6032 24.00 2N6033 27.00 2NB034 1.20 2N6035 1.30 2N6036 1.40 2N6037 1.02 2N6038 1.10 2NB039 1.30 2N6040 2.80 2N6041 2NS042 2N6043 2N6044 2N6046 2N6049 2 N 6050 2N6061 2N6052 2N6053 2NG064 2N6055 2N605B 2N6057 2N605B 2N6059 2N606B 2N6069 2N6070 2N6071 2N6072 2N6073 2N6074 2N607G 2N6076 2N6077 2N6078 2N6080 2N6081 2N6082 2N6084 20.00 2N6094 14.70 2N6095 16.00 2N6096 21.00 2N6097 23.00 2N6099 .87 2N6103 2N6107 2N6109 .84 2N6111 .84 2N6116 1.61 2N6117 2.66 2N6118 3.20 2N6121 .90 2N6122 .90 2N6123 1.05. 2N6124 .90 2N8125 .90 2N6126 1.05 2N6129 1.23 2N6130 1.36 2N6131 1.51 2NB132 1.26 2NB133 1.41 2N6134 1.54 2N6136 29.10 2N6145 6.90 2NG146 2N6147 2N6151 2N6162 2N6153 2N6154 2N6155 2N6166 2N6167 2N616B 2N6169 2N6160 2N6161 2N6162 10.40 2N6163 8.80 2N6164 10.10 2N6165 12.10 2NS186 54.00 2N6167 5.35 3 00 3.30 2.50 2.70 3.00 2.30 2.30 2.60 2.80 1.50 3.96 6.44 12.30 13. BO 15.50 1.10 m ^gs • 10%* DISCOUNT COUPON Bring this TOI'IMIX into one of ourstores or mail to our Mail Order address shown below and receive a 10% DISCOl'VT on purchases from this page of $50.00 or more. OhVr KXIMIIKS on April .'10. 1 1MI I ^Coupons accepled 7.80 9.30 2.86 3.93 4.83 6.70 7.30 7.10 B.42 2N616B 6.50 2N6169 7.30 2N6170 8.80 2N6171 6.45 2N5172 7.B0 2N6173 10.20 2N6174 12.10 2N61B6 36.60 2N61B7 40.60 2NB18B 40.50 2N61B9 63.00 2N6190 12.90 2N6191 19.00 2N6192 16.90 2N6193 21.70 2N6211 2N6212 2N6213 2N6220 2N6226 2N6227 2NB228 2N6229 2N6230 2N6231 2N6233 7.6B 2N6234 7.85 2NB235 B.14 2N6236 .94 2N6235 8.14 2NB236 .94 2N6237 1.00 2N6238 1.03 2N6239 1.16 2N6240 1.61 2N6241 2.74 2N6249 7.30 2N6250 8.66 2N6251 878 2N6265 2.80 2N6266 10.70 2N6257 2.58 2N6274 21.70 2N6276 26.00 2N6276 34.00 ZN6277 46.00 2NB282 2NB283 2 N 6384 2 N 6286 2N6286 2N6287 2N628B 2.48 2.98 3.40 .60 1.68 1.BB 2.19 2.98 3.56 4.36 5.30 5.90 5.90 6.30 6.90 2 N 62 90 2 N 62 92 2N6294 2N6295 2N6296 2NB297 2N6298 2N6299 2N6300 2N6301 2N6303 2N6304 2N6305 2N6306 3.80 2N6307 2N6308 2N6312 2N6313 2N6314 2N6315 2N6316 2N6317 2N631B 2N6326 2N6327 2N632B 2N6329 2NB330 2M6331 2N633B 2N6339 2N6340 17.90 2 N 6341 20.90 2N6342 1.60 2N6342A 2.06 2N6343 2.10 2N6343A 2.40 2N6344 2.90 2N6346 6.60 2N6345A 6.20 2N6346 1.90 2N6346A 2.20 2N6347 2.26 2N6347A 2.60 2N6348 3.00 2N6348A 3.60 2N6349 5.80 2N6349A 6 60 2NB354 5.40 2N6368 38 50 2N6370 3B.60 2N6377 22.70 2N637B 30.80 2.20 2.40 9.80 2.10 6.00 1.60 1.80 2.30 1.70 1.90 2.10 21.5 3.20 3.60 4.10 3.60 4.00 4.40 B.50 9.90 CAPACITORS • CAPACITORS • CAPACITORS ALUMINUM ELECTROLYTIC H MFD 10V 16V 25V 35V 60V 21 .23 2B 220 .23 26 22 24 .30 24 .26 .32 .30 .36 35 40 .50 40 .45 .55 45 60 .80 65 80 1 .20 30 1.60 2.50 ZENER DIODES 500 mW — 5% 1N5240B 16 .22 1N5247B 17 .22 1N524BB 18 .22 1N6249B 19 .22 1N5250B 20 22 1N5261B 22 .22 1N5262B 24 22 1NS253B 26 .22 1N52&48 27 22 1N52658 28 .22 V Pi 1N5256B 30 1N5257B 33 1N5258B 36 1N6259B 39 1N5260B 43 1N5261B 47 1N5262B 51 22 1N5263B 56 22 1N5264B 60 .22 1N5265B 62 22 V Pricn 1N52B6B B8 .22 1N6267B 76 .22 1N6223B 27 22 1N5224B 2.8 .22 1N5225B 3.0 .22 1NS226B 33 22 1N5227B 3.6 .22 1N622BB 3.9 .22 1N5229B 4 3 22 1NG230B 4.7 .22 1N5231B 5.1 22 1N52328 5 6 22 IN5I33L! 5.0 .22 1N5234B 6.2 22 V Prico 1N5235B 6.B .22 1NG230B 7.5 .22 1N6237B 8.2 22 1N5238B 8.7 22 1N5239B 9.1 .22 1N5240B 10 .22 1N6241B 11 .22 1NG2428 12 .22 1N5243B 13 .22 1N5244B 14 .22 1N5245B 16 .22 50V CERAMIC DISC— $1 .00 Per Pack 9/pkg 9/pkg 9/pkg 9/pkg 8/pkg 8/pkg B/pkg 8/pkg 8/pkg 7/pkg 5p( 7/pkg iepf 7/pkg 25pf 7/pkg 27pl 7/pkg 47pf 7/pkg 6Sp[ 7/pkg 100 [>f 9/pkg 150 pf 9/pkg 220pf 9/pkg 270pf 9/pkg 300pf 330pf 390pl 470pf 560 pf eSOpf .001 mtd .0015mtd O022mfd OOSmtd 9/pkg 9/pkg 9/pkg B/pkg 8/pkg 8/pkg B/pkg 7/pkg 7/pkg 6/pkg .0047mfd 005 mid 01 mid .01 6 mid .02 mid .022 mid 03mld .039mld .047 mid ELNA DIPPED TANTALUM 10.0 10.0 35 16.0 20 16.0 35 1. 22.0 16 33.0 20 1. 47.0 20 1. 68.0 16 1. PLESSEY POLYESTER (MINI-BOX) 001 1000 .14 .012 0012 1000 .14 .015 0015 1000 .14 .016 0018 1000 .14 .022 0022 1000 .14 .027 0027 1000 .14 .033 0033 1000 .14 039 0039 630 .14 .047 0047 630 .14 .056 0056 630 .14 .068 0068 630 .14 .082 0082 630 .14 2N6379 44.70 2N63B3 2.10 2N63B4 2N63B5 2N6386 2N63B7 1.17 2N638B 1.26 2N6394 1.80 2N6395 1.82 2N6396 2N6397 2N639B 2N6399 2M64O0 2N6401 2N6402 2N6403 2N6304 2N64Q5 2N6420 2N6403 2 N 6304 2N6420 2N6421 2N6422 2N6423 2N6424 2NB425 2N6426 .63 2N6427 .61 2N6428 .76 2N6428A 1.00 2N6429 .76 2N6429A 1.00 2N6430 2.60 2N6431 2N6432 2M6433 2N6436 2N6437 16.00 2N643S 20.40 2N6439 56.00 2N6466 1.11 2MB487 1.20 2N6488 2N6489 2N6490 2N6491 2N6497 2N649B 2N6499 2NB501 2B.00 2N6603 23.10 2.36 2.64 1.05 2.80 2.60 2.80 9.90 1.29 1.11 1.20 1.29 2.79 3.40 4.90 2IM6504 2N6505 2N6506 2N6507 2IM6508 2N6509 2N651S 2AI6516 2N6517 2N6518 2N6619 2N6520 2N6530 2 N 6531 2N6532 2N6533 2N6S42 2N6543 2N6544 2N6545 2N6546 2IM6547 2N6548 2N6549 2N6551 2NB552 2N6553 2N6564 2N6555 2N6556 2N6557 2N6568 1.13 2N6559 1.33 2N6569 1.12 2N6691 1.13 2N6592 1.26 2N6593 140 2N6603 13.60 2N6604 13.60 2N6609 2N6648 2N6649 2N6666 2N6667 2NSB68 2N6671 2N6672 2N6673 2N6674 2NB675 900 3N83 1.80 3N84 1.80 3NB5 3.00 1.26 1.36 1.60 1.60 3.20 4.30 6.40 5 50 1.00 1.17 460 2.20 2.50 600 6.80 7.50 C PLESSEY ZENER DIODES 1 WATT — 5% V Price 1N472BA 3 3 40 1N4729A 3.6 .40 1N4730A 3.9 40 1N4731A 4.3 .40 1N4732A 4.7 .40 1N4733A 5.1 .40 1N4734A 5.6 .40 1N4735A 6.2 .40 1N4736A 6.8 .40 1N4737A 7.5 .40 1N473BA 8.2 .40 1N4739A 9.1 40 1M4740A 10 .40 1N4741A 11 .40 1N4742A 12 40 1N4743A 13 .40 1N4744A 15 .40 1N474BA 16 40 1N4746A 18 .40 1N4747A 20 .40 1N4748A 22 40 1N4749A 24 40 1N4750A 27 .40 1N4751A 30 40 1N4762A 33 40 1N4753A 36 .40 1N4754A 39 .40 1N4755A 43 .40 1N4766A 47 40 1N47&7A 61 ,40 1N4768A 56 40 1N4759A 62 40 1N4760A 6B 40 1N4761A 75 57 VISIT A STORE NEAR YOU TODAY - We slock a large selection of Technical Books, Discrete Componsnts, Integrated Circuits. Test Equipment and Electronic Supplies. ATLANTA 3330 Piedmont Rd. N.E. Atlanta, GA 30305 (404) 261-7100 CULVER CITY 1 1080 Jefferson Blvd. Culver City, CA 90230 |213) 300-3595 HOUSTON 2649 Richmond Houston, TX 77098 (713) 529-3489 PORTLAND 1125 N.E. 82nd Ave. Portland, OR 97220 (503) 254-5541 SANTA ANA 1300 E. Edinger Ave. Santa Ana, CA 92705 (714) 547-8424 SUNNYVALE 1054 E. El Camino Real Sunnyvale, CA 94087 (408) 243-4121 TUCSON 4518 E. Broadway Tucson, AZ 8571 1 (602) 881-2348 370 BYTE April 1981 Low Profile — TIN 1-24 25up SOup 1 17 S .16 S 15 S A8ZT-TI A14ZT-TI A16ZT-TI .22 .21 .20 .19 A18ZT-TI .29 .28 .27 .26 A20ZT-TI .33 .32 .31 .30 A22ZT-TI .36 35 34 33 A24ZT-TI .37 .36 .35 .34 A28ZT-TI .43 .42 41 .40 A40ZT-TI 46 .45 .44 43 Standard Soldertail — TIN A22T .72 .71 .70 69 A24T .52 .51 50 .49 A2BT .78 .77 76 .75 A36T 83 .82 81 80 A40T 1.0B 1,07 1.06 1.05 Standard Soldertail— Gold 1-24 25up 50up 100up A16G A18G A22G A24G A28G A36G A40G SOCKETS WIRE WRAP Level 3 A8WG A10WG A14WG A16WG A18WG A20WG A22WG A24WG A28WG A36WG A40WG 1.35 1.43 1.83 1.95 2.43 1.22 1.21 1.20 Wire Wrap — TIN A8WT-TI A14WT-T! A16WT-TI A18WT-TI A20WT-TI A22WT-TI A24WT-TI A28WT-TI A36WT-TI A40WT-TI * MICROPROCESSOR CRYSTALS • 2.4SJB 3.I7II 3.S7I CASE P/N PRICE HC33 CY1A J9.50 HC33 CD1A 9.50 HC31 CV2A ■ 75 HC]J CY2B 125 HC3J CT3I 60S HCJJ CT3D 6 00 KCH CY3» SOB HC1I CV4C 5.00 KCtl CVIB B.OO HC18 CY5A HC18 CV7A HC1S CY5B HC1B CB5C HC1I CY5B HI 18 CY6C HC18 CY8G HC1B ( 12A 14.11918 HC1B CY14A 4 75 IRBO MKi) CASE P/N I I5.B0 HC18 CY15A : 18.00 HC1B CY19A IB 432 HC18 CY19B 19 66BB KCia CY70A 20.00 KC1B CY72A 21.684 HC1B CY23B 7700 HC1B CY27A 37.00 HC1B CY37A [lil DO HC1B CY100A FIBER OPTICS from MOTOROLA The Link Kit Only.... Aqq f~.fi ^-Wjjjmmjt^M • provides an optical link capable of I x-mittingdataat NRZrateto20 mb/s • allows familiarity with fiber optics ^Kv while experimenting with actual circuits fcr systems • has basic design ^ equations and examples • illustrates general applications of fiber optics Flasher LED FRL-4403 Red LED and Flasher IC Chip ONLY in One Package QOp LED BAR GRAPH ARRAYS AND DRIVER GL-112R3 LEO Array is a red LED arrangad in a 12 dot bar graph configuration. When used in combination with tho IR-2406, linear luvel indications can be generated. GL-112M2 LED Array same as above ex- cept dot graph is arranged as 8 green and 4 red positions. IR-2406 LED Driver is an integrated circuit LED driver with 1 2 outputs. Each successive output turns the LED's an in steps equal to: VraffrVtOM.} - Vroff Mln.)/1 3 \ OEM Prices GL-112R3 $4.80 GL-112M2 $4.80 IR-2406 $4.80 The Bright TWO-COLOR LED Both Red-orange and Green LEDs in E D95 the eame package. Color mixing can 1-24 — $1.60 be accomplished due to separate anodes. H si -in 74LS.. .Series 74LS00N $ .21 74LS03N .23 74LS04N .26 74LS08N 27 74LS10N .24 74LS1 IN 74LS20N 74LS22N 74LS26N 74LS27N 74LS32N 74LS37N 74LS40N 74LS42N 74LS73N 74LS74N 74LS86fg 74LS90N 74LS93N 74LS109N 74LS1 I2N 74LS123N 74LS12SN 74LS126N 74LS132N 74LS136N 74LS138N 74LS139N 74LS145N 1.20 74LS151N 74LS152N 74LSI53N 74LS160N 74LS161N 74LS162N 74LSI63N 74LS164W 74LS170N 2 65 74 LSI 74 N 74LST75JJ 74LS181N 2.30 74 LSI 90N 1.20 74LS19IN 89 74LS193N .89 74LS194N .85 74LS195N .65 74LS221N .85 74LS240N 95 74LS241N .90 74LS243N 99 74LS244N .95 74LS245r\ 2.20 74LS251N 2.20 74LS253N .59 74LS257N .60 74LS258N 65 74LS260N .65 74LS266N 48 74LS273N 1.35 74LS299N 2.60 74LS365N 75 74LS366N 79 74LS367N 70 74LS373N 1.45 74LS374N 1 40 74LS377N 1.40 74LS381N 2.90 74LS490N 1.80 VOLTAGE REGULATORS LM300H LM300N LM304H LM305H LM309H LM309K LM317H 1.70 LM317-To220 1.60 LM3I7K 2.45 LM320-5K 2.20 LM320-6K LM320-8K LM320-12K LM320-15K LM320-18K LM320-24K LM323K LM340-5K LM340-6K LM340-8K 1.45 2.20 2.20 2.20 2.20 2.20 4.70 1 35 1.35 1.35 LM340-12K 1.3J LM340-15K 1.3! LM340-18K 1.3! LM340-24K 1.3: LM350K LM353-5 LM353-8 LM353-12 LM353-15 LM353-18 LM3D3-U LM723CH LM723CN 78L05ACP 78L05CP 78 LOS AC P 78L08CP 78L12ACP 78L12CP 78L15ACP VOLTAGE REGULATORS To220 (Plastic) 7815CP 7818CP 7824CP To220 (Plastic) 7905CP $.9! 791 2CP .9! 791 5C a .9! 791 8CP .9! 7924CP .9! (Dire SILICON GENERAL Linear IC and Voltage Regulator Databook 214 pages $4.50 RF TRANSISTORS MRF207 S 1.61 MRF208 16.06 MRF209 19.27 MRF212 22.48 MRF215 40 15 MRF216 43.29 MRF221 15.22 MRF222 17.67 MRP223 18.50 MRF224 21.65 MRF314 28.91 MHF314A 28.91 MRF454 26.53 MRF454A 26.53 MRF455 22.34 MRF455A 22.34 MRF475 4 05 MRF901 3.00 MRF904 3.21 MRF911 2.89 MRF8003 2.44 MRF8004 2.93 1.00 1.00 1.00 1.00 78L15CP 78L18ACP 78L18CP 78L24ACP 78L24CP 79L03ACP 79L03CP 79L05ACP 79L05CP 79L12ACP 1.50 79L12CP 1.00 79L15ACP 1. 79L15CP 79L18ACP 79L18CP 79L24ACP 1 50 79L24CP 1.00 MC1463G 4.90 MC14661 9.90 MC1468G 5.90 MC1469G 4.90 To220 Case 78M05CT S .85 78M06CT 1,45 78M08CT 1.45 78M12CT 1.45 78M15CT 1.45 78M18CT 1.45 78M20CT 1.45 78M24CT 1.45 Motorola's Complete Opto Triac Driver Line J* JJf Typ. m« VoIt MOC3009 15 251 MOC3O10 8 251 MOC3011 5 251 MOC3020 15 401 MOC3021 8 401 MOC3030' 15 251 MOC3031* 8 25t 11 H m -E&; *io%* • DISCOUNT COUPON Bring this COITMIN into one of ourstores or mail to our Mail Order address shown below and receive a 10% IHM OIXT on purchases from this page of $50.00 or more. Offer riVI'l HIS on April SO. I Oil I S= ANCRONA HAS INTERSIL ICs Z-80 SERIES 2.5 MHz Z-80-CPU $ 8.95 2-80-CTC 6.50 Z-80-P10 6.50 '-DART 15.45 '-DART-9 13.50 Z80-S10/0 24.40 Z-80-S10/9 18.20 -DMA 20.10 4.0 MHz Z-80A-CPU S 9.95 Z-80A-CTC 7.95 Z-80A-P10 7.95 Z-8QA-DART 1 8.85 Z-80A-DART-9 1 6.50 Z-80A-S10/0 30.50 Z-80A-S10/9 23.40 Z-80A-DMA 24.90 IM610D-1PL IM6102-1PL ICM7038-A1PA ICM7038-C1PA ICM7045 ICL71C03-ACP1 ICL7106-CPL ICL7107-CPL 1CL7116-CPL ICL7117-CPL ICM7201-1DR ICM7205-1PG ICM7206-CJPE 1CM7207-A1PD ICM7208-1PI ICM7209-1PA ICM7211-1PL S13.95 14.50 3.00 3.00 14 95 13.80 15.50 15.00 2.25 13.00 5.15 6.60 ICM7213-1PD 1CM7215-1PG ICM7216-A1J1 ICM7216-B1P1 ICM7216-C1J1 ICM7216-D1P1 ICM7217-A1P1 ICM7217-B1J1 ICM7217C1P1 ICM7217-1J1 ICM7218-C1J1 ICM7223-1PL JCM7224-IPL ICM72251PL ICM7226-A1J1 ICM7226B1PL 1CM7227-A1P1 SS.36 13.95 32.00 28.65 26.65 21.40 11.25 12.40 10.35 12.40 10.76 7.90 11.26 8.60 32.00 28.65 12.40 ICM7227-B1J1 ICM7227-C1P1 ICM7227-1J1 ICM7240-1JE 1CM7241-1PA ICM7242-1JA ICM7250-1JE ICM72G0-1JE IC>%r17270-1PL 1CM7555-1PA ICM7556-1PD ICL7G60-CP.A ICL8038-CCJD ICL8048-CCPE ICLB069-CCQ ICL8211-CPA 14.48 12.40 14.46 4.90 3.40 2.05 6.00 5.26 5.8S 1.20 2.25 3.00 4.70 21.60 2. BO 2.60 6800 SERIES MC6800P S 5.90 MC6801L1 65.84 MC6802P 1 1.50 MC6805U2P2 30.72 MC6808P 13.90 MC6809P 36.50 MC6821P 3.46 MC6828P 9.90 MC6840P 12.22 MC6843P 45.39 MC6844P 45.39 MC6845P 22.00 MC6846P1 39.90 MC6846P3 66.50 MC6847P 16.06 MC6850P 3.40 MC6852P 3.50 MC6854P 32.26 MC6859L 277.90 MC6860P 10.80 MC6862P 11.80 MC6875L 6.90 MC6880AP 3.14 MC6881 P 8.91 MC6882AL 6.13 MC6885P 2.72 MC6886P 2.72 MC6887P 2.72 MC6888P 2.72 MC6889P 3.14 IS BETTER 2114L3 $ 4116 (200ns) 2708 2716 (5 V) 2732 (450ns) 2732 (350ns) 1-10 3.90 3.90 5.90 9.90 24.90 26.90 10 up > 3.20 3.20 5.30 9.30 23.90 25.90 100 up $ 3.00 3.00 5.00 9.00 22.90 24.90 Our Very Special 64K Dynamic RAM HM4864 $65.00 $63.00 $59.00 ANCRONA Stocks Only FIRST QUALITY! 6502 SERIES P6502 S 6.40 P6502A(2MHj!| 7.90 P6502B|3MHJ) 13.50 P6503 970 P6503A 10.70 P6504 9.30 P6504A 10.70 P6505 9.30 P6505A P6506 P6506A P6507 P6507A P6512 P6512A P6513 P6513A P6514 P6514A PG515 P6515A P6520 P6520A P6521 P6521A P6522 PG522A P6532 PS532A 13,70 9.70 10.70 3.70 10.70 10.70 S16.60 9.70 10.70 9.70 10.70 9.70 10.70 5.90 G.40 6.20 6.80 6.40 11.90 7.80 10.20 8080A— 8085A and Support ICs P80B0A S5.00 P8085A 10.00 P8212 2.30 P8212B 4.50 P8216 2.10 8224 PC 3.10 P8226 2 40 8228PC 5.80 P8237 22.00 8238PC 6.00 P8251 6.40 P8253 13.00 P8255A 6.10 P8257 1 1 .90 P8279 15.90 DP8303N 3.90 DP8304BN 3.90 DP8307N 3.90 DP8308N 3.90 Z8000 SERIES Z8001 DC S150.00 Z8002DC 140.00 Z8065DC 99.00 Z8073PC 25.20 Z8104PC 4.90 Z8107PC 4.90 Z8108PC 4.90 Z8120DC 5.60 Z8121 PC 3.65 Z8127DC 19.60 Z8133PC 2.50 Z8136PC 5.20 Z8140PC 3.00 Z8144PC 3.60 Z8148PC 3.00 Z8164BPC 24.40 Z8165PC 7.65 Z8166PC 7.65 Z8173PC 2.10 RS232 CONNECTORS DB25P male 2.95 DB25S female 3.60 HOODS 1.75 SET 7.50 NMOS MICRO- PROCESSOR MC68000L S347.73 MC63000L4 291.87 MC68000L6 319.80 MC68488P 19.80 MC68705P3L1 11.72 NMOS EPROM MCM68708CS 32.26 MCM68764C 309.89 MCM68766C 309.89 g U California Uj" Computer mJI Systems For Commodore Computers 32K STATIC HAM MODULE (ASSEMBLED AND TESTED) 2032A 450ns HAM $710. OD 20328 30Dns RAM. 795.00 2032C 200ns RAM. . B30.00 64K DYNAMIC HAM MODULE (ASSEMBLED AND TESTED} 20B5C 200ns RAM. S700.00 I6K STATIC RAM MODULE (ASSEMBLED AND TESTED) 2116A 450ns RAM S349.95 21 1GB 300ns RAM 383.95 2116C 200ns RAM 399.95 MAINFRAME 2200A Assy and Tested $399.95 2200 K Complete Ht ... 349.95 Nnle: Spec, color- Black, Blue. Brown, Office Cream, or Grey. FLOPPY DISK CONTROLLER Z422A Assy E> Tested. . . S400.00 4-Port Serial I/O Inlerfaco 2710A Assy Er Tested. . S340.00 Sorial/Parallel I/O Interface 2718A Assy&Tesled... $360.00 4-Porl Parellel I/O Interface 2720A Assy&Tesled. . $2511.00 z-ao~ cpu 2810A Assy&Tesled. . . $300.00 For Apple Compute 7440A Assembled and Tested . PROGRAMMABLE TIMER PARELLEL INTERFACE 7720A Assy Blest cable &s!d firmware. . . $119.95 77208 Assembled and tested: cable & CenKanics-lype firmware included . SI 19.95 STORES DO PJDT ACCEPT MAIL ORDERS MAILORDER P.O. BOX2208Y CULVER CITY. CA90230 PHONE ORDERS (213) 641-4064 mm Order SIOQO Add S2 00 lo co.er postage and handling MasierCnaige and VISA welcomed Please include yem charge card number interbank number and narration date Some cams are subtect to prror sale Not responsible for ttpos State pricing may vary Irom Marl Order pricing We reserve the light to substitute ABITHMETIC PROCESSOR 7811 B Assembled and tested; CCsoll diskette included [ Comualibte with Apple II " computers with a disk dtivel S399.95 781 IC Assembled and tested; CCsult ROM included (Compatible with Apple II PLUS * compu lets and Apple II" computers with an Applesoft'" card ) . S399.95 7424A Assy & Tested Less ball ASVNCHROIMUS SERIAL INTERFACE 771DA Assy h tested; cable included. . . S159.95 CALENDER/ CLOCK MODULE SYNCHRONUS SERIAL INTERFACE 7712A Assy b tested cable included . SI 79 95 GPIB IIEEE-48B) INTERFACE 7490A Assy b tested; cable included S300.00 CENTRONICS" PRINTER INTERFACE 7728A Assy& tested; cable not in ANCRONA HAS MOTOROLA ICs BFR90 BFR91 CA3054 CA3059 CA3079 MBD101 ME3D102 MBD201 MBD501 MCE63P MC664P MC665P' MC6S7P MCG68P MC677P MC678P MC6BOP MC6B4P MC830L MCB32L MCB35L MCB36P MC837P MC839L MC839P MC840P MC846P MC84BL MC866P MC857L MC857P MC862L MC958L MC1013P MC1302P SI 8B 2.42 1.54 3.34 2.23 .73 ,2B 1.03 1.57 3 20 3.20 1.91 3.20 1.91 2.05 2.05 2.05 5.10 227 227 2.46 1.50 585 3.56 1.50 1 36 3.17 2.14 2.46 1.50 2,27 2.46 ,50 3.72 MC1309P MC1310P MC1330A1P MC1349P MC1350P MC1351 P MC1352P MC1355P MC13S7P MCI 358 P MC1364P MC1372P MC1373P MC1391P MC1403AP MC1403AU MC1403UDS MC1405L MC140BL6 MC140BL7 MCI 408 LB 2,10 2.01 2.10 1.55 1.50 2.01 6.48 6,19 1.44 3.78 11.07 4.23 1S.28 2.94 4.75 4.64 MC140BPB 4,40 MC1413P 1.33 MC1436CU 7.99 MC1437L 3 99 MC1437P 3.14 MC1439G 4 99 MC1439L 4.62 MC1439P1 3.97 MC1445G 4.20 MC1445L 4.15 MC1445P1 .72 MC1445UDS 1.77 MC1456G 2.25 MC1456P1 1 96 UC1458CL MC1458CP1 MC1458P1 MC1458P1S MC1469G MC1469R MC1488L MC1489AL MC1489L MC14B9P MC1494L MC1495L MC1496G MC1B04L MC180BP MC1B09P MC1810P MC3062L MC3302L MC3302P MC3303P MC3325P MC3340P MC3360P MC3370P MC3403P MC3405P MC3408L MC3416L MC3423P1 MC3438L MC3448AP MC3470P MC3476P1 MC3S03L MC4016P MC4024P MC4026P MC4044P MC4316L 1 MC455BNCP1 MC8311 P MC9819P MC1O104P MC10109L MC10116L MC10116P MC10123L MC10124L MC10125L MC10131P MC10137L 2 MC10159P MC10189L MC10195L MC10198P 3 MC10216L MC10231P MC12O40P 1 MC120B1P MC14410P 2 MC14411P 1 MC14412VP 1 MC14436VP 1 MC14457P MC14458P 1 MC14490FP MC1449DVP MC14495P MC34004P VISIT A STORE NEAR YOU TODAY - We stock a large selection uf Technical Boohs, Discrete Components. Integrated Circuits, Test Equipment and Electronic Supplies. ATLANTA 3330 Piedmont Rd. N.E. Atlanta, GA 30305 (404) 261-7100 CULVER CITY 1 1080 Jefferson Blvd. Culver City, CA 90230 (213) 390-3595 HOUSTON 2649 Richmond Houston, TX 77098 (713) 529-3489 PORTLAND 1 125 N.E. 82nd Ave. Portland, OR 97220 (503) 254-5541 SANTA ANA 1300 E. Edinger Ave. Santa Ana, CA 92705 (714) 547-8424 SUNNYVALE 1054 E. El Camino Real Sunnyvale, CA 94087 (408) 243-4121 TUCSON 4518 E. Broadway Tucson. AZ 8571 1 (602) 881-2348 Circle 275 on inquiry card. BYTE April 1981 371 DATA PRECISION A DIVISION OF ANALOGIC CORPORATION MODEL DESCRIPTION PRICE 1 75 3'/. Digit Portable D.M.M. S21 9.00 245 4-/2 Digit Portable D.M.M. 385.00 248 4V, Digit Portable True RMS D.M.M. 385.00 100-Hour Mini- Portable 41/2-Digit LCD Multimeter • 25 Ranges, including five each AC and DC. both voltage and current, plus five resistance rangesl • Sensitivities of 1(V(V. 10nA. lOOmfi. and maximum readings of 100 volts (500 AC), 2A. 20 megohms! • Basic accuracy of ±0.03%. supportod by lab-grade T.C. — typically. ±(0.003% rdg. + 0.001% rng.)/ "C • Rechargable 100-hour battery portability, plus line operation (while charging) • Big. clear, high-contrast 0.43" high LCD readout, readable anywhore you can see to work . . . including bright sunlight! MODEL 255 $295.00 258 4Vi Digit Portable True RMS D.M.M. 585 8 Digit Portable 250MHz Frequency Coi 385.00 395.00 3Vi Digit- LCD Display DIGITAL MULTIMETER • Unique Audible "Eyes-Off" multi-testing • Fast testing without taking your eyes off the circuit you're probing. • Continuity Test works on three lowest resistance ranges. • Repetitive Alarm warns of AC overload or accidental applications of AC voltage to OHMS input. • Single-tone alarm on negative DC overvoltage. • Also tests logic levels - logic tran- sistors — relay or switch opening and closing — diode and transistor junctions — ev MODEL 936 $190.00 Capacitance Meter • Easy to use -plug in capacitor, push range button and read the value to 0.1% • 0.5 in. liquid crystal display • Exclusive "Acharge/Avolt" measure- ment circuit (patent pending) holds ±0.1 % basic accuracy for a full year. • Up to 200 hra operation on standard 9V Batt. • 8 easy pushbutton ranges cover 0.1 pf 1999 microfarads. • Best of all it's easy on the budget - only MODEL 938 $185 0.1° Resolution, LCD Display TEMPERATURE METER • WIDE-RANGING — [~l 65°C to + 150°C»(-)85 o to 302° F • ACCURATE — ± .4 C/±0.7°F over most of range • FAST— 8 seconds to 99% of final change in reading • VERSATILE — switch-se- lectable resolution (0.1° or 1") and degrees C or F • HANDY — easy to carry, hold, use. read • TOUGH — takes everyday field usage yet main- tains calibration. • COMPLETE — includes full- measurement range probe. • USED EVERY- WHERE — internal 9V battery or line operation (1 1 5AC, 47 - 63 Hz) with optional battery eliminator. MODEL 940 $195.00 1350 1351 1750 2480 2480 R 5740 5800 5801 5845 3'/) Digit Bench D.M.M. 3VS Digit Bench D.M.M. with 20A 3Vi Digit Bench/Portable True RMS and dB D.M.M. 4'/j Digit Bench/Portable D.M.M. 4Vz Digit Bench/Portable True RMS D.M.M. 7 Digit 100MHz Multifunction Counter 8 Digit 520MHz Bench/Portable Frequency Counter 8 Digit 520MHz Bench/Portable Frequency Counter 8 Digit 150MHz Multifunction Counter 215.00 205.00 360.00 330.00 350.00 325.00 485.00 525.00 340.00 SIGNETICS The Instructor 50 $350oo Desktop Computer rery thing you need to and debug machine- Red. Our Price Pan No. DP1002-2 32K 81395.00 $1016.00 HHM 10 Megahertz HM307 SINGLE TRACE OSCILLOSCOPE IDEAL SERVICE INSTRUMENT TIME BASE 0.2 /is - 2.0 s/cm LPS-TRIGGER ■ COMPACT BUILT-IN COMPONENT TESTER NO DISCOUNT COUPON FOR ITEMS ON THIS PAGE CALL FOR QUOTE ON QUANTITY DISCOUNTS Only S404.25 20 Megahertz HM312 DUAL TRACE OSCILLOSCOPE I 10 x 8 cm DISPLAY I LPS-TRIGGERING ■ BANDWIDTH DC — 20MHz ■ TRIGGERING up to 30MHz ■ FULLX- Y OPERATION Only S58O.0O 50 Megahertz HM512 DUAL TRACE OSCILLOSCOPE SWEEP DELAY DELAY LINE BRIGHT DISPLAY BANDWIDTH DC — 50MHz TRIGGERING up to 70MHz AFTER TRIGGER DELAY LINE OVERSCANNING INDICATION IDEAL FOR COMMUNICATIONS AND DATA PROCESSING Only $1 485.00 KEITH LEY 3V 2 Digit Hand-Held DIGITAL MULTI METER MODEL 130 —0.5% basic DCV accuracy • 25 ranges and 5 functions: DC volts, AC volts. DC amps. AC amps and ohms • Auto zero and auto polarity • Low battery indicator and much much more $11 5.00 MODEL131 —0.25% basic DCV accuracy • 25 ranges and 5 functions: DC volts, AC volts. DC amps, AC amps and ohms • Diode test • Auto zero and auto polarity • Low battery indicator and much more $134.00 4!/ 2 Digit LCD Hand- Held DIGITAL MULTIMETER 0.05% DCV accuracy • 4V4- digit resolution • 5 functions • Easy to read. 6" LCD display • 100- hour life from an akaline battery • Annunciator warns user when 10% of battory life remains • Reliable rotary switches clearly display range and function • Fully protected from overload: 1000V max DCV. 1000V peak ACV and 300V max Ohms • 10A current range • ACV bandwidth to 20KHz MODEL 135 $219,00 4Vi Digit Bench/Portable DIGITAL MULTIMETER MODEL 176— 0.5% accuracy below 20VDC and20KHzAC • 20000 count display • 0.6" LCD display • 5 Func- tions: DC volts. AC volts, DC amps, AC amps and ohms • Function and range annunciators • 1000 hour battery life typical MODEL 176 $249.00 MODEL 1 78 — 0.04% basic accuracy • 20000 count display • 0.6" LED display • 1400V input protection • Easy to use • 3 Functions: DC voiys, AC volts, ohms $249.00 1 304 Carrying Case $1 0.00 1 766 Battery Eliminator 40.00 1 788 Rechargeable Battery Pack 79.00 50 Megahertz HM812 DUAL TRACE STORAGE OSCILLOSCOPE ■ 50 MHz DUAL TRACE PLUS VARIABLE PERSISTENCE ■ DELAYED SWEEP WITH AFTER DELAY TRIGGERING ■ STORAGE OF SINGLE-SHOT-SIGNALS "AUTOMATIC STORE" ■ LED INDICATION FOR OVERSCAN, SINGLE SHOT, TRIGGER ACTION DELAY MODE, "AUTOMATIC STORE" Only $4035.00 4V4 Digit LCD Bench/Portable DIGITAL MULTIMETER • 2000 count display • 0.6" LCD display • Function and range annunciators • 5 Functions; DC volts, DC amps, AC volts, AC amps and ohms • Fully protected • 1-year battery life from alkaline battery • Quality and performance The K Oft Way 169 provides full capability for many genera I purpose applications. Seldom-used functions have been eliminated to keep the price/performance ratio high. MODEL 169 $169.00 Universal Oscilloscope Probe S— $ 36 :oo SWITCHABLE XI and X10 Attenuation Factor KEY ADDITIONAL FEATURES: • 100MHz bandwidth • Heavy duly tip • Break resistant center conductor • Slender, flexible cable • 6ft. cable length • Wide compensation range • Fits all scopes • Ground reference can be activated at tip • Includes SPRUNG HOOK, l.C. TIP, BNC ADAPTOR. INSULATING TIP and TRIMMER TOOL ACCESSORIES. STORES 00 NOT ACCEPT MAIL ORDERS MAILORDER P.O. BOX2208Y CULVER CITY, CA 90230 PHONE ORDERS (213) 641-4064 Minimum Order SID 00 Add S'l OD to cover postage and handling Master Charge and VISA welcomed Please include your charge card nomber, interbank number and etptralmn date Some ilcms are suli|er.l to nrioi sale Nol responsible lor lypus Store pricing may vary from Mail Order pricing. We reserve the right to substitute THANDAR Pulse Generator (lott c bottom) • Independent Period and Pulse Width Controls • Period Range 200ns — 200fts (5MHz — 5Hz) • Pulse Width Ranga 100ns — 100/is • Varible 5011 and Fixed TTL Outputs • TTL Output Capable of Driving 20 Standard TTL • Can Be Operated in Triggered. Gated. Manual One- Shot or Manual Gated Modes • Complement Switch Inverts Both Outputs TG105 Only $219,00 Frequency Meter ( eft c ■°P) • 10Hz — 200 MHz (Resolution Ippm across measure- ment range • 5 Selectable Gate Times • Input Better than 30 mV rim Across Full Range and Better than lOmV rms from 20Hz — 100MHz • W 8-Digit LCD Display • Automatically Positioned Decimal Point • Totalise Mode For Frequencies Up To 20Mhz • 1 M Hz Int. Timebase Available via Rear Panel Socket • Indicates Units Being Measured (KHz or MHz) TF200 Only S394.00 TP600 600MHz Proscaler Only $98.00 VISIT A STORE NEAR YOU TODAY - We stock a large selection of Technical Books, Discrete Components, Integrated Circuits, Test Equipment and Electronic Supplies. ATLANTA 3330 Piedmont Rd. N.E Atlanta, GA 30305 (404) 261-7100 CULVER CITY 1 1080 Jefferson Blvd. Culver City, CA 90230 (213) 390-3595 HOUSTON 2649 Richmond Houston, TX 77098 (713) 529-3489 PORTLAND 1 125 N.E. 82nd Ave. Portland, OR 97220 (503) 254-5541 SANTA ANA 1300 E. Edinger Ave. Santa Ana, CA 92705 (714) 547-B424 SUNNYVALE 1054 E. El Camino Real Sunnyvale, CA 94087 (408) 243-4121 TUCSON 451 8 E. Broadway Tucson, AZ 8571 1 (602) 881-2348 372 BYTE April 1981 HICKOK DIGITAL MULTIMETERS LX-304 LX-303 S7995 Dual Trace Oscilloscope HITACHI 30 MHz • TV sync-separater circuit • High-sensitivity 1mV7div (5MHz) • Sweep-time magnifier (10 times) • Z-axis input (Intensity modulation) • Signal delay line • X-Y operation • Trace Rotation Model V302B $995 DMM + VARI-PITCH + LOGI-TRAK = MX-333 s 235 © PLESSEY Metallized Polyester Capacitors Series 160 I "^MINIBOX SAMPLER S26.00 AP PRODUCTS 923101 . . S 79.95 923102. . . 124.95 923103. . . 124.95 MARK IV LED POWER LEVEL INDICATOR R>po« • Display Range -36dB to+5dB vary bam Mail Order pricing We leserve the Jig hi to substitute manufacturei Quite Portable Very Affordable and Unbelievable Versatile the PET computer may very well be a lifetime investment • Large Keyboard • Separate Numeric Pad • Graphics on Keys commodore 16KS Professional Keyboard Kits! Models 753 Er 756 ASCII Keyboard Kits For Hobby or OEM Microprocessor Users • Full 128 Character ASCII (756) • 53 Keys, popular ASR-33 format (753| • Rugged G-10 P.C. Board •Tri-mode MOS an- coding. • Two Key Rollover | MOS/TTL/OTL Compatible out- puts • Shift and Alpha Lock(756) • Level end Pulae Strobo(756) • Custom Keycaps • 3 User Dafinable Keyi(763) • Selectable Parity • Low Bounce Keyswitchat* And Much Morellf 753K 63 Key phona style keyboard-Kit . . . $65.95 753A Same as above assembled $79.95 756K 50 Key Full ASCII keyboard kit $69.95 756A Same as above assembled $82.95 701 Plastic enclosure for 753/756 $15.00 702 Steel enclosure (or 753/756 $29.95 753MF Mounting Frame for 763 $6.95 756MF Mounting Frame for 756 $6.95 CARBON FILM RESISTORS FULL LEAD • HIGH QUALITY • 5%TDL 10 33 100 11 36 110 12 39 120 13 43 130 IB 47 150 16 51 160 18 56 180 20 62 200 22 68 220 24 75 240 27 82 270 30 91 300 330 1.0K 360 1.1K 390 1.2K 430 1.3K 470 1.5K 510 1.6K 660 1.8K 620 2. OK 680 2.2K 750 2.4K 820 2.7K 910 3. OK 3.3K 3.6K 3.9K 4.3K 4.7K 5. IK 5.6K 6.2K G.8K 7.5K 8.2K 10K 33K 100K 11 K 36K 110K 12K 39K 120K 13K 43K 130K 15K 47K 160K 16K 51K 160K 18K 56K 180K 20K 62K 200K 22K 68K 220K 24K 75K 240K 27K 82K 270K 30K 91 K 300K 330K 1.0M 360K 1.1M 390K 1.2M 430K 1.3M 470K 1.5M 510K 1.6M 560K 1.8M 620K 2.0M 680K 2.2M 750K 2.4M 820K 2.7M 910K 3.0M 3.3M 3.6M 3.9M 4.3M 4.7M 5.1M 5.6M 6.2M 6.8M 7.5M 8.2M 10. OM % Watt $1.69 per C Vfc Watt $1.79 per C ORDER ONLY IN MULTIPLES OF 100 PIECES PER VALUES CfcQ 1C 2 WATT M*Ci lw 10 P/Pack $2.10 1 WATT 20 P/Pack AVAILABLE IN THE FOLLOWING VALUES IN OHMS 3.3 ISO 300 560 1.5K 3.0K 5.6K 20K 47K 180K 680K 10 180 330 680 1.8K 3.3K 10.0K 22K 56K 220K 1.0M 47 200 390 820 2. OK 3.9K 12.0K 27K 68K 330K 2.2M 100 220 470 1.0K 2.2K 4.7K 15. OK 33K 100K 390K 4.7M 120 270 510 1.2K 2.7K 5.1K 18. OK 39K 150K 470K 10. OM 3 1 /2-Digit, LCD-Display DIGITAL MULTIMETER • HANDY — easy to hold, to carry, to use. to read. • ACCURATE — basic 0.1% DC accuracy - • TOUGH — built to tnke rough everyday field usage and electrical overload . . . yet maintain its calibration • VERSATILE — big, clear, high con- trast 3 '/i- dig it LCD display, readable anywhere ... a full 0.5 " high. • PORTABLE — Palm-si*ed. light- weight operates up to 200 hours an a single 9V transistor alkaline battery. • EXPANDABLE — uses standard DMM accessories to extend ranges even further. MODEL 935 $175.00 POWER SUPPLY 5 Volt 3 Amp APS 5-3 1-9... S37.25 10 up. .. $35.55 25 up.. $34.04 XR2206KB FUNCTION GENERATOR KIT OPERATES ON EITHER: SINGLE 12V J-.6V SPLIT SUPPLY INCLUDES ALL PARTS TO BE MOUNTED ON PC BOARD Only $19.95 POWER SUPPLY NOT INCLUDED m • 10%* DISCOUNT COUPON Bring this COUl/OBt into one of our stores or mail to our Mail Order address shown below and receive a I 0% DISCOUNT on purchases from this page of $50.00 or more. Otter EXPIRES on April .10. I »» I NAME ADDRESS. CITY STATE PHONE NO Coupons accepted only with full name and address fille 91 PORTABLE thondor OSCILLOSCOPE • DC-IOMHz • 2" Diagonal CRT • SMALL SIZE (10"xS.8"x(2") • ULTRA LOW POWER CONSUMPTION Only $369 LIGHT WEIGHT |2 ib.) AUTOMATIC CIRCUIT POWER DOWN FOR UNUSED SECTIONS HIGH QUALITY CARBON FILM RESISTOR KITS % Watt — 5% Tolerance EACH SET CONTAINS 840 RESISTORS 20 each of the following values (in ohms| i .on i on i oon i .OKn i OKn 1 ooKn i.oun i .5n i sn 1 5on i .5Kn 1 5Kn 1 50Kn i .5Mn 2.2n 22fi 220« 2.2Kn 22Kn 220Kn 2.2MH 3.3n 33H 3300 3.3Kn 33Ktt 330Kn 3.3Mn 4.7n 47H 470n 4.7Kn 47Kn 470Kn 4.7Mn 6.an 6Bn6son 6.8Kn 68Kn 660Kn ,68n RS-14-25 Complete w/StorogB Bin $ 24 90 NEW 30 MEGAHERTZ PORTABLE, DUAL TRACE MINI-SCOPE 30MEGAHERT2 MS-230 Du.t T>*a $649.00 15 MEGAHERTZ MS-215 D U .ir, ac8 ' S497.00 MS-15 Single, !..-.= ., $389.01) PORTABLE and LIGHT WEIGHT EXAR XR-032CP XR-083CP XH-084CP 1-24 25up100up i 1.39$ 1.11 $ .93 XR-C 4CP XR-095CP XR-096CP XR-246P XR-346CP XR-346-2CP XR-205CN XR-210CN XR-215CN XR-C240 XR-C262 XR-C277 XR-320P XR-5ESCP XR-L555CP XR-556CP XR-L556CP XR-558CP XR-559CP XR-567CP XR-L567CP XR-U5BCP XH-U68CN XR-1488P XR-1489AP XR-1524M XR-156BN XR-2200CP XR-220! CP XR-2202CP 1.58 1.30 4.80 4.00 3.38 2.81 3.38 2.81 ■ 4.22 10.22 9.28 7.43 6.19 8.06 6.45 5.38 XR-2203CP XH-2204CP XR-2206CP XR-2207CP XR-2208CP XR-2209CP XR-2211CP XR-22I2CP XR-221BCP XR-2228CP XR-2240CP XR-2242CP XR-2271CP XR-227 2CP XR-2276CP XR-2284CP XR-2268CP XR-2524P XR-2556CP XR-2567CP XR-3403CP XR-3524CP XR-4136CP XR4151CP XR-4195CP XR-4212CP XR-4558CP XR-4741CP XR-5533P XH-5533AP XR-5534CP XR-5534ACP XR-6118P XR-6128P XR-8038CP XR-13600CP .94 .79 4.22 3.28 2.79 2.63 4.93 .94 .79 3.38 2.81 2.63 2.19 2.23 1.86 2.10 1.75 3.94 3.29 3.45 2.88 2.57 2.14 2.23 1.86 1.59 1.33 1.53 1 .27 I. IB 1.99 3.66 8.72 4.03 1.59 1.33 2.93 2.44 6.98 5.81 3.22 2.69 11 2.49 2.07 1.94 1.61 2.50 2.09 1.59 1.33 2.64 2.25 2.25 3.75 1.82 VISIT A STORE NEAR YOU TODAY - We sleek a large selection of Technical Books. Discrete Components, Integrated Circuits, Test Equipment and Electronic Supplies. ATLANTA 3330 Piedmont Rd. N.E. Atlanta, GA 30305 (404) 261-7100 CULVER CITY 1 1080 Jefferson Blvd. Culver City, CA 90230 (213) 390-3505 HOUSTON 2649 Richmond Houston, TX 77098 (713) 529-3400 PORTLAND 1 125 N.E. 82nd Ave. Portland, OR 97220 (503) 254-5541 SANTA ANA 1300 E. Edinger Ave. Santa Ana, CA 92705 (714) 547-0424 SUNNYVALE 1054 E. El Camino Real Sunnyvale, CA 94087 (408) 243-4121 TUCSON 4518 E. Broadway Tucson, AZ 8571 1 (602) 881-2348 Circle 276 on inquiry card. BYTE April 1981 373 o LOWEST PRICES ON THE Pan onthe^J; Jj^ American Electronics a Radio /hack Computers For Business, Learning and Entertainment INCORPORATED For More Information Call TOLL FREE ORDER NUMBER 800-531-7466 Texas & Principal NUMBER 512-581-2765 Telex Number 767339 Dept. B, 1117 Conway Mission, Texas 78572 o o 00 cippkllplu/ With 48Kof s memory! 51195 With the purchase ol the APPLE Hi select Irom the below 1 SPECIAL PRICING! 8ase~ 2 printer. S599 01 DIsklMconl ...585' Distill 475"> Ser.PrinlerCd... 179^ SupRIUod 23" 3waylK3Select.. 33" videotex) tz:.... m- FirmwareCard. 179"° 'MFtoRCACabl^°°^ 74LS00 .26 74LS155 1.15 74LS02 .26 74LS158 75 74LS03 26 74LS160 95 74LS04 .26 74LS161 74LS08 .28 74LS162 95 74LS09 .26 74LS163 160 74LS10 .26 74LS164 65 74LS20 .26 74LS165 65 74LS21 28 74LS170 175 74LS22 .26 74LS174 75 74LS26 .49 74LS175 .75 74LS27 26 74LS190 75 74LS30 .28 74LS193 .95 74LS32 .32 74LS195 .95 74LS38 .32 74LS196 85 74LS42 65 74LS221 1.40 74LS48 .78 74LS240 165 74LS51 25 74LS241 1.65 74LS54 .35 74LS243 145 74LS74 .38 74LS244 1.45 74LS75 .60 74LS245 2 25 74LS83 44 74LS253 95 74LS85 .95 74LS257 .95 74LS86 95 74LS258 .95 74LS90 .69 74LS259 2 85 74LS93 .69 74LS279 44 74LS107 45 74LS283 100 74LS112 38 74LS293 1.85 74US113 .48 74LS298 120 74LS122 48 74LS366 95 74LS123 .95 74LS367 .55 74LS126 .69 74LS368 .55 74LS138 69 74LS373 1.39 74LS151 .44 74LS374 139 74LS153 .44 74L! kll/oppkllpki/ With64Kpf memory! 51389 flw>u inTERPflcc ennw cinmonKf MnTu i m commuiwuTioni <•**•**.■<•**• m MIHIICOmHOUM <».•.*.). J Mt MKM UUMUMf NKHMI 4W COLOR $397* EPROMS 2708 Ik x 8 5.95 8 FOR 40.00 2716 2k x 8 9.95 single p.s 8 FOR 80.00 2732 4k x 8 24.95 2716 2k x 8 6.96 tnpte p.a. L— d«x Corp appk ckxk, cakA-9Vdc @ + 16Vdc @-16Vdc @+28Vdc 3y4"x3 5 /„"x3'/ 8 " 3 3 /."x4f x3/," 3V4"x4f*x3%" 3V*"x3%"x3%" 3"x3"X2'/2" SIZE WxDxH 21.95 27.95 29.95 22.95 14.95 UNIT PRICE KIT 1 15 CARDS SOURCE 15A KIT 2 SYSTEM SOURCE 25A KIT 3 DISK SYSTEM 15A 1A 2.5A 3A 2A 2.5A 3A 2A 4A 12"x5"x4'/ a " 12"x5"x4'/ a " 14"X6"X4'/," 52.95 59.95 67.95 DISK SYSTEM PWR SUPPLY S3 assy. & tested, open frame, size to"(W)x6"(D)x4%"(H) 92.95 UNREGULATED OUTPUTS: +8V@12A, ±16V@3A. REGULATED OUTPUTS: +5V@4A, -5V@1A, +24V@4A, SHORTS PROTECT. IDEAL FOR THE SYSTEM WITH 10SLOTS MAINFRAME & TWO 8" DISK DRIVES, SUCH AS SHUGART801R OR SIEMANS FDD 100-8. (OPTION: OVP for +5V @ ADD $5.00) DISK DRIVE POWER SUPPLY "R3" assy. & tested, open frame, size 9"(W)x6y< "(D) x4%"(H) 67.95 SPECS: +5V @ 5A REGUL, OVP, - 5V @ 1A REG., + 24 @ 5A REG., SHORTS PROTECT. OPTIONS: 1. REPLACE + 24V BY +12V 2. ADD ± 12V @ 1A, $12.00 MORE. IDEAL FOR 2 SHUGART 801/851 OR SIEMANS FDD 100-8/200-8 DISK DRIVES & ROCKWELL AIM-65. SHIPPING FOR EACH TRANSFORMER: $4.75. FOR EACH POWER SUPPLY: $5.00 IN CALIF. $7.00 IN OTHER STATES. CALIF. RESIDENTS ADD 6% SALES TAX. OEM WELCOME. MAILING ADDRESS: P.O. BOX 4296 TORRANCE, CA 90510 SUNNY INTERNATIONAL (TRANSFORMERS MANUFACTURER) (213) 328-2425 MON-SAT 9-6 SHIPPING ADDRESS: 22129V2 S. VERMONT AVE TORRANCE, CA 90502 et: Yes! We supply IMSAI y compatible products. NOTE: "Original" IMSAI parts were purchased at the closing business sale of IMSAI Manufacturing Corp. WW Components also distributes S-100 buss IMSAI compatible parts and boards. As supplies of "original" parts are exhausted, WW reserves the right to supply equivalent compatible parts not made by IMSAI. All items listed as "Assembled & Tested" have been assembled by WW Components and carry a 1 year warranty. 1-8080 S-100 THE ORIGINAL IMSAI: Mainframe with blue cover, cardguides and hardware ENCLOSURE spaced for PS-28D Power Supply, up to 22 slot motherboard. Sheet Metal Kit Kit of all metal parts and hardware w/docs $1 1 5.00 Thinker Toys WunderBuss20 for above w/o conn. $79.00 Complete 8085 based CPU including: serial RS-232 port, parallel I/O port 3 MHz operation, 256 bytes memory, ROM monitor, 3 timers, and more. Assembled & Tested $250.00 Mounts in the I-8080 enclosure, supplies +8V @ 28A, +/- 16V @ 3A, kit includes board, transformer, documentation, and all components. KIT $95.50 The complete 8085 system, includes MPU-B, RAM III, 10 slot terminated mother- board, PS-28D, and jump start front panel. A complete 64K system! Assembled & Tested $1250.00 NOW AVAILABLE - CP/M for the IMSAI floppy disk system. Version 2.2 is available for the DI0-C 8" controller. Others on request. Docs. incl. 8" Diskette & Manuals $1 75.00 Ask about documentation, repair service, firmware and software for your system. MPU-B SBC 8085 CPU PS-28D Power Supply Parts Kit: 1-8015 Complete System w/MPU-B CP/M ® 2.2 for IMSAI TERMS: (1) PREPAID Send check or M.O. for merchandise amount only - we pay the shipping in USA only. (2) UPS COD or bankcard orders by phone or mail - shipping charges added. California Residents add 6.5% Sales Tax. 85 5 B 5 1 ft 376 BYTE April 1981 Circle 281 on Inquiry card. yc/t- P.O. Box 4430X Santa Clara, CA 95054 ELECTRONICS INTEGRATED CIRCUITS Will calls: 2322 Walsh Ave. (408) 988-1640 TWX 910-338-2139 Same day shipment. First line parts only. Factory tested. Guaranteed money back. Quality IC's and other compo- nents at factory prices. 74Q0TTI 740QN 7402N 7404N 7409N 7«tON 74 UN 7420N 7422N 7430N 7442N 7445N JAA7U 7448N M50K 7474N 7475N 7485N 74B9N l 7490N 7492IJ 7493N 7495N 74I00N I 74I07N 74121N 74123K 74125N 74145N 741MN I 74151N 741 bW l 741 57N 7416IN 74162N M1B3N 74174N 7417SN 7419DN 1 74192N 741 BUN 7422 IN 1 ?msn 1 74365N 74366N 74367N 74LS00 TTl 74LSDQN 74LS02N 74LS04N 74LS05H 74LS08N 741SKW 74LSI3N 74LSI4N 74LS20N 74LS22N 35 74LS28N 35 74LS30N 35 74LS33N 60 74LS38N 50 74LS74N .45 74LS75N 65 74LS90N 60 74LS93N 75 74LS95N 1 00 74LS107II 45 74LS1I2N 45 74LS113N 45 74LSI32H 99 74LSl36fl 50 74LS151H 75 74LS155N 79 74LS157N I ID 74LS162N I 10 MLS163N t 10 741S174H I 15 74LS190II 1 25 74L5221N 1 25 74LS256H 1 00 74LSM7PI 69 UHEAR CA3Q45 90 CA3046 1 10 CA30B1 I 80 CA3082 1 90 CA30B9 3 40 IM301ANAH 35 LM305H 87 LM307N 35 LM308S 1 00 LM309K 1 25 LM311HH 90 LM317T LM317K LM320K-5 1 35 LM320K-12 1 35 LM320K-15 135 LM320T-5 95 LM320T-8 95 LM320T-12 95 LM320T-15 95 LM323K-5 5 95 LM324N 1 00 LM339N I 00 LM340K-5 1 35 LM340K-8 ) 35 LM340K-12 135 LM340K-15 I 35 LM340K-24 I 35 LM34QT-5 85 LM340T-8 85 LM340T-12 85 LM340M5 B5 LM340T-18 85 LM340T-24 65 LM350 5 50 LM377 2 95 LM379 5 00 LM380N I 00 LM381 1 60 LM382 1 GO LM709H LM723H N LM733H LM741CH LM741N LM747H N LM748N LM1303N LM1304 LM1305 LMI307 LM13I0 LM145B LMIB12 LMI889 LM2111 LM2902 LM3900N LM3905 LM3909N MC 1458V NE550N NE555V NE556A NE565A NE566V NE567V NE570B 78L05 78L08 78M05 75108 75491CN 75492CN 75494CN 22 00 LM31B 1 50 B700CJ B7Q1CN B750CJ 13 95 LD130 9 95 9400CJV F 7 40 ICL7103 9 50 ICL7107 14,25 CMOS CD4000 25 CD 400 1 35 CD4002 35 C04006 1 10 CD40O7 35 CD4008 1 20 CD4009 45 CD4Q'0 45 CD4011 35 CD4012 28 C04013 47 C04014 CD4015 C04016 CD4017 CD4018 CD4019 CD4020 CD4021 C04D22 CD4023 CO4024 CD4025 CDJ026 CD 402 7 CD402B CD4029 CD4030 CD 4035 CD-1040 CD. 1042 C[}.:u.l3 CD 4044 CD4046 CD4049 CD4050 CD4051 CDJ060 CD 4066 CD4066 CD4069 CD4070 CD4071 CD4072 CD4Q73 CD4075 CD4076 CD407B CD4081 CO4082 CD4116 CSJ4490 CO4507 CD4506 CD4S10 CD4511 CD4515 CD4516 CD4518 CD4520 CD4527 CD452B CD « 53 CD4566 CDJ5B3 CD4535 CD40I92 74CO0 74C0J 74C1Q 74CH 74C20 74C30 74C48 74C74 74C76 74C90 74C93 74C154 74C160 74C175 74C192 74C221 74C905 7JC905 74C914 74C922 Ft 74C923 74C925 74C926 74C927 2 50 21 ML -150ns 4 00 66 4116 200ns 4 50 65 8-4 116 200ns 26 95 I 35 MM5262 40 45 MM5280 3 00 1 00 MM5320 9 95 1 35 MM5330 5.94 85 PD4110-3 4 00 B5 PD41ID-4 5 00 .85 P5101L B 95 167 4200A 9.95 45 82325 2 90 60 91L02A 1 50 I 13 HD0165-5 695 1 42 MM57100 4 50 71 GIAY3850O-I 9 95 40 MCM66751A 9 95 40 9368 3 50 50 4100 10.00 45 416 16 00 f, CLOCKS •W MM5311 5 50 '■g MM5312 3 90 « MM5314 3.90 « MM5369 2 10 35 MM5841 14 45 -tl MM5865 7 95 ?.™ CT7010 B9S 1*89 CI7015 8 95 2 =■? UM537SAA/N 3 90 1 ™ MMS375AGN 490 -« 7205 16 50 2 ,% im IC SOCKETS Solder Tin Low Pralim PIN 1 UP PIN 1UP WIRE WRAP LEVEL 3 53 -e, ASCII ieytraatd kit Fully assembled Enclosure Plaslic Metal Enclosure 70 00 14 95 29.95 7208 S 7209 9f DS0026CN IJ DS0056CN ?0 MM5310J 18 67 40 CRYSTALS 1 MHl 2MHl 4 MM; 5MHi 10 MH: 18 MH; 20 MKj- 32MHi 32768 Hi I t 8432 MH; I 3 5795 tAHl I 2 0100 MH; ! 2 097152 Mil; 1 2 4576 MH; 1 3.2768 MH; 1 5 068B MH; 5 185 MH; 5 7143 MH; 6 5536 MH; 14 31B18MH; 40 6802 35 6820 B9 6B50 35 8080A 35 3 95 12 95 75 00 8096 8097 8098 BT09 8T10 8T13 BT20 BT23 8T24 8T25 BT26 ST28 95 8086 85 Z80 1 33 1 25 280A 1 1 95 1 25 82'2 2 90 1 25 8214 3 95 3 50 8216 2 90 2 75 8224 3 45 1 35 8228 4 95 1 65 8251 6 95 1 90 8253 15 00 6 00 8255 5 75 75 8357 10 95 1 95 B259 14 95 5 00 IB02CP nlas 13 95 5 50 !802DPplas 17 95 7 50 1861P 9 50 kqs COP1BQ2CD 28 95 em CDP1B02D 35 00 CDP1B16P 7 95 55 UART7FIF0 65 AY5-1013 5 50 65 AY510I.' 65 3341 1 25 450 PROM 3.00 I702A 4.95 5 50 270B 6 10 3 10 271611 18 00 3 50 2716 5 Won 10 50 3 20 B 2716 5 Vol! B9 00 169 2732 29 50 2 75 2756 19 50 KEYBOARD ENCODERS AY5-2376 SI2 50 AY5-3600 17 95 AY5-910O 10 50 AY5-9200 16 50 74C922 5 50 74C923 5 50 HD0165 5 6 95 AYS-9400 10 50 Connecton RS232 DB25P 3 62 OB25S 5 20 Cover l 67 0E9S 1 95 0A15P 2 10 0A1SS Complete Set 6 95 9 50 HJckok 3^ Dlgll LED mul- llmitif S9.95 SlapwUch Kit 26. 95 Aulo Clock XII 17.95 Olgldl Clock KI1 tl.95 IK-'IBKEprom Kit (less PROMS) SB9 00 Molherhoird $39 00 Eilender Baud $15 00 28 8T98 t 69 8748 47 8748-8 1 25 B755A 1 00 MOS/MEMOfiY RAMNB2S23 55 2101-1 3.85 NB2S123 I 05 2102-1 95 N82S126 94 2I02AL-4 1 45 N82S129 45 2102AH-2L 165 N82S131 1 02 2104A-4 4 95 NB2S136 1 35 2T07B-4 3 75 N82S137 1 10 2111-1 3 75 DMB577 28 2112-2 3.95 8223 75 2114 3 75 28 2114L300ns425 RESISTORS '< wait 5« 10 oer type 25 per lyuc 100 oer lyoe 03 025 015 1000 per type 350 oiece M 5 pet type 012 6 75 '7 win 5'. pe type 05 Televldio Termlnil Model 912 $785 00 Model 920 S8B5 00 Tlirr BltlC Fiy i-.-l.-i-cr.l::'! HI 110. DO LEDS Red TOIfi 15 Green. Yellow T01B 2D Jumoo Ret) 20 Green. Orange. Verio* Jumoo 25 Clisiiie LED Mounting Clips 3S1 25 (specrly reO amber green, yello*. Clurl COHTINEHTAL SPECIALTIES In itoclt Complete line ot DreaoooarO teat egurp Max- 100 B digit Frag. Clr. 1149.95 Complete line ot *P Products In ate SPECIAL PRODUCTS MM5B65 Slop.atcn T.mer with 10 pg spec a PC noaro I SarlteAea '.torn Puanounoo 3 poa slide Encoder HD01655 « Parilronica Moflel 10 Trigger EapanOer Kit S22l Model 150 Bus Grabber Krl S36S Clock Calandar Kit S2r 2.5 MHa Fieguency Counter Kit 131 30 MH; Fraguancr Couniar all HI TRANSFOHMEOS 5V 300 ma ! 12 Voll 300 ma transformer ' l2 6VCT600ma ! 12V 250 ma wall plug 1 12V CT 250 ma wall plug 24V CT 100 ma : 10V I 2 amp wall plug ■ 12V 5 amp IS 12V 500 ma wall plug ' 12V 1 amp wall plug I 10 15 VAC B 15 VA wall plug < DISPLAY LEDS MANl MAH3 MAH72 74 C DL704 DL707 DL707R DL727 728 C DL747.750 C FFID359 FND500507 FNQ5O3 5I0 FIID800B07 3 Orgil Bubble 10 Oign Orspia 7520 Clarre. c TIL311 He. MAN3540 MAW610 MAW4640 MAN4710 MAN4740 MANB540 MAII6710 MAN6740 CCCA I CC CA I CCCA I MA1007A. C. E MA1012A I02P3 tranalormer MA10I2A Tltnalormar DIP Swllcttea 4-0054100 S 95 5-position 1 00 6-posmnn 1 00 B-obsmon 1 D5 Cbmplole lino ot Kooby-Bloa sol oeness OreaOboanJs In stock IC Starlei Pack S5.95 Discrete Component Starter Pack S8.S7 PROM Eraser assembled. 25 PROM capacity $37.50 (with timer $69.50). 6 PROM capacity OSHA/ UL version $69.50 (with timer $94.50). Z80 Microcomputer 16 hit I/O, 2 MHz clock, 2K RAM, ROM Bread- board space. Excellent for control. Bare Board S28.50. Full Kit $99.00. Monitor $20.00. Power Supply Kit $35.00. Tiny Basic $30.00 S-100 Computer Boards 8K Static Godbout Econo IIA Kit 149.00 16K Static Godbout Econo XIV Kit 269.00 24K Static Godbout Econo XX-24 Kit 414.00 32K Static Godbout Econo XX-32 Kit 537.00 16K Dynamic RAM Kit 289.00 32K Dynamic RAM Kit 328.00 64K Dynamic RAM Kit 399.00 Video Interface Kit $139.00 80 IC Update Master Manual $39.00 Comp. IC data selector, 2700 pg. master reference guide. Over 51 ,000 cross references. Free update service through 1980. Domestic postage $3.50. Modem Kit $60.00 State of the art, orig., answer. No tuning neces- sary. 103 compatible 300 baud. Inexpensive acoustic coupler plans included. Bd. only S1 7. 00. LRC 7000 -Printer 5389.00 40/20 column dot matrix impact, std. paper. Interlace all personal computers. 64/40/32/20 version $405.00. Optional cables available. LRC 7000 printer interface cable for Super Ell Willi software $35.00 NiCad Battery Fixer/Charger Kit Opens shorted cells that won't hold a charge and then charges them up, all in one kit w/full parts and instructions. $7.95 Rockwell AIM 65 Computer 6502 based single board with full ASCII keyboard and 20 column thermal printer. 20 char, alphanu- meric display, ROM monitor, fully expandable. $405.00. 4K version $450.00. 4K Assembler $85.00, 8K Basic Interpreter $100.00. Special small power supply for AIM65 assem. in frame $54.00. Complete AIM65 in thin briefcase with power supply $499.00. Molded plastic enclosure to fit both AIM65 and power supply $47.50. Special Package Price: 4K AIM, 8K Basic, power supply, cabinet $625.00. AIM65/KIM/VIM/Super Elf 44 pin expansion board; 3 female and 1 male bus. Board plus 3 connectors $22.95. 60 Hz Crystal Time Base Kit $4.40 Converts digital clocks from AC line freguency to crystal time base. Outstanding accuracy. Video Modulator Kit $9.95 Convert TV set into a high quality monitor w/o affecting usage. Comp. kit w/full instate. Multi-volt Computer Power Supply 8v 5 amp, »18v .5 amp. 5v 1.5 amp. -5v .5 amp, 12v .5 amp, -12v option. ±5v, ±12v are regulated. Basic Kit $29.95. Kit with chassis and all hardware $43.95. Add S4.00 shipping. Kit of hardware $14.00. Woodgrain case $10.00. $1.50 shipping. RCA Cosmac 1802 Super Elf Computer $106.95 Compare features before you decide to buy any other computer. There is no other computer on the market today that has all the desirable bene- fits of the Super Ell for so little money. The Super Ell is a small single board computer that does many big things. It is an excellent computer for training and for learning programming with its machine language and yet it is easily expanded with additional memory, Full Basic, ASCII Keyboards, video character generation, etc. Before you buy another small computer, see if it includes the following features: ROM monitor; State and Mode displays; Single step; Optional address displays; Power Supply; Audio Amplifier and Speaker; Fully socketed for all IC's; Real cost of in warranty repairs; Full documentation. The Super Ell includes a ROM monitor for pro- gram loading, editing and execution with SINGLE STEP for program debugging which is not in- cluded in others at the same price. With SINGLE STEP you can see the microprocessor chip opera- ting with the unique Quest address and data bus displays before, during and after executing in- structions. Also, CPU modeand instruction cycle are decoded and displayed on 8 LED indicators. An RCA 1861 video graphics chip allows you to connect to your own TV with an inexpensive video modulator to do graphics and games. There is a speaker system included for writing your own music or using many music programs already written. The speaker amplifier may also be used to drive relays for control purposes. plus load, reset, run, wait, input, memory pro- tect, monitor select and single step. Large, on board displays provide output and optional high and low address. There is a 44 pin standard connector slot for PC cards and a 50 pin connec- tor slot for the Quest Super Expansion Board. Power supply and .sockets for all IC's are in- cluded in the price plus a detailed 127 pg. instruc- tion manual which now includes over 40 pgs. of software info, including a series of lessons to help get you started and a music program and graphics target game. Many schools and univer- sities are using the Super Elf as a course of study. OEM's use it for training and R8aD. Remember, other computers only offer Super Elf features at additional cost or not at all. Compare before you buy. Super Ell Kit $106.95, High address option $8.95, Low address option $9.95. Custom Cabinet with drilled and labelled plexiglass front panel $24.95. All metal Expan- sion Cabinet, painted and silk screened, with room for 5 S-100 boards and power supply $57.00. NICad Battery Memory Saver Kit $6.95. All kits and options also completely assembled and tested. Questdata, a software publication for 1802 com- puter users is available by subscription for $12.00 per 12 issues. Single issues $1.50. Is- sues 1-12 bound $16.50. Tiny Basic Cassette $10.00, on ROM $38.00, original Elf kit board $14.95. 1802 software; Moews Video Graphics $3.50. Games and Music $3.00, Chip 8 Interpreter $5.50. A 24 key HEX keyboard includes 16 HEX keys Super Expansion Board with Cassette Interface $89.95 This is truly an astounding value! This board has been designed to allow you to decide how you want it optioned. The Super Expansion Board comes with 4K ol low power RAM fully address- able anywhere in 64K with built-in memory pro- tect and a cassette Interface. Provisions have been made for all other options on the same board and it fits neatly into the hardwood cabinet alongside the Super Elf. The board includes slots for up to 6K of EPROM (2708, 2758, 2716 or Tl 2716) and is fully socketed. EPROM can be used for the monitor and Tiny Basic or other purposes. A IK Super ROM Monitor $19.95 is available as an on board option in 2708 EPROM which has been preprogrammed with a program loader/ editor and error checking multi file cassette read/write software, (relocatable cassette file) another exclusive from Quest. It includes register save and readout, block move capability and video graphics driver with blinking cursor. Break Quest Super Basic V5.0 A new enhanced version of Super Basic now available. Quest was the first company worldwide to ship a full size Basic for 1802 Systems. A complete function Super Basic by Ron Cenker including floating point capability with scientific notation (number range I.17E 38 ). 32 bit integer ±2 billion; multi dim arrays, string arrays; string manipulation; cas- points can be used with the register save feature to isolate program bugs quickly, then follow with single step. If you have the Super Expansion Board and Super Monitor the monitor is up and running at the push of a button. Other on board options include Parallel Input and Output Ports with lull handshake. They allow easy connection of an ASCII keyboard to the input port. RS 232 and 20 ma Current Loop for teletype or other device are on board and if you need more memory there are two S-1 00 slots for static RAM or video boards. Also a 1K Super Monitor version 2 with video driver for full capa- bility display with Tiny Basic and a video interlace board. Parallel 1/0 Ports $9.85, RS 232 $4.50, TTY 20 ma l/F $1.95, S-100 $4.50. A 50 pin connector set with ribbon cable is available at $15.25 for easy connection between the Super Elf and the Super Expansion Board. Power Supply Kit for the complete system (see Multi-volt Power Supply ). Ohio Scientific Computers CIP Series 2 $455.00. Like an Apple at less than half the price! CIPMF Series 2 $1199.00. Minifloppy version with additional RAM/ROM. Complete software and peripherals available. Send for free brochure. Gremlin Color Video Kit $69.95 32 x 16 alpha/numerics and graphics; up to 8 colors with 6847 chip; 1K RAM at E000. Plugs into Super Elf 44 pin bus. No high res. graphics. On board RF Modulator Kit $4.95 1802 16K Dynamic RAM Kit $149.00 Expandable to 32K. Hidden refresh w/clocks up to 4 MHz w/no wait states. Addl. 16K RAM $63.00 Tiny Basic Extended on Cassette $15.00 (added commands include Stringy, Array, Cas- sette I/O etc.) S-100 4-Slot Expansion $ 9.95 Super Monitor VI. I Source Listing $15.00 sette I/O; save and load, basic, data and ma- chine language programs; and over 75 state- ments, functions and operations. New improved faster version including re- number and essentially unlimited variables. Also, an exclusive user expandable command library. Serial and Parallel I/O included. Super Basic on Cassette $55.00. Elf II Adapter Kit $24.95 Plugs into Elf II providing Super Elf 44 and 50 pin plus S-100 bus expansion. (With Super Ex- pansion). High and low address displays, state and mode LED's optional $18.00. Super Color S-100 Video Kit $129.95 Expandable to 256 x 192 high resolution color graphics. 6847 with all display modes computer controlled. Memory mapped. 1K RAM expanda- ble to 6K. S-100 bus 1802, 8080, 8085, Z80etc. Dealers: Send lor excellent pricing/margin program. Editor Assembler $25.00 (Requires minimum of 4K lor E/A plus user source) 1802 Tiny Basic Source listing $19.00 Super Monitor V2.0/2.1 Source Listing $20.00 TERMS: $5.00 min. order U.S. Funds. Calil residents add 6% tax. $10.00 min. BankAmericard and Master Charge accepted. $1.00 insurance optional. Postage: Add 5%. COO. $10.00 min. order. FREE: Send lor your copy ol our NEW 1980 QUEST CATALOG. Include 48c stamp. Circle 282 on Inquiry card. BYTE April 1981 377 Circle 283 on inquiry card. Add-On Disk Drive Subsystems FOr Apple, TRS-80, S-100 Based Computers Expansion and enhanced capabilities are key words in achieving full utilization of your computer system. Our complete line of LOBO disk drive subsystems are the ideal, cost-effective way to provide the expansion capabilities you need to meet your system growth reguirements. All of our subsystems are complete, thoroughly-tested, 100% burned-in, and feature a 1 year 100% parts/labor warranty. APPLE 3101 Minifloppy, 31011 Minifloppy w/interlace card 8101CA One SA800 in cabinet w/power, DDC* Controller, cable and manual 8202CA Two SA800 in cabinet w/power, DDC* Controller, cable and manual 5101CA One SA850 in cabinet w/power, DDC* Controller, cable and manual 5202CA Two SA850 in cabinet w/power, DDC* Controller, cable and manual "Double Density Controller S-100 BASED COMPUTERS MODEL NO. DESCRIPTION 4101C SA400 in cabinet w/power 821 2C Two SA801 in cabinet w/power 521 2C Two SA851 in cabinet w/power GENERAL MODEL NO. DESCRIPTION 8212 Two SA801 in cabinet 821 2C Two SA801 in cabinet w/power 5212 Two SA851 in cabinet 521 2C Two SA851 in cabinet w/power TRS80 MODEL NO. DESCRIPTION MODEL NO 41 01 C SA400 in cabinet w/power C808 81 01 C II One SA800 in cabinet w/power lor Mod. II LX80 8202C II Two SA800 in cabinet w/power lor Mod. II RS232 C802 CableforMod.il 16K C805 Cable lor TRS80 Minifloppy VTOS DESCRIPTION Cable lor TRS80 Eight-inch Floppy Double-density expansion interface Dual Serial Port Option 16K Byte RAM lor LX80 (32KB max.) 4.0 Disk Operating System INVENTORY CO., P.O. Box 185, Santa Y»iez,Ca., 93460 (805) 688-8781 STANDARD RS232 CABLES PART NO. DESCRIPTION PRICE RS232MM9 Male to male 9 ft. cable 24.00 RS232MM18 Male to male 18 ft. cable 29.00 RS232MF9 Male to female 9 ft. cable 29.00 RS232MF18 Male to female 18 ft. cable 34.00 RS232FF9 Female to female 9 ft. cable 34.00 RS232FF18 Female to female 18 ft. cable 39.00 RS232M09 Male to open 9 ft. cable 18.00 RS232M018 Male to open 18 ft. cable 23.00 RS232F09 Female to open 9 ft. cable 24.00 RS232F018 Female to open 18 ft. cable 29.00 DISK DRIVE POWER CABLES PART NO. DESCRIPTION PRICE PDC-5 5%" DC PowerConnector24" lonq 6.00 PAC-8 8" AC Power Connector 24" lonq 6.00 PDC-8 8" DC Power Connector 24" long 7.00 PAC-8D 8" AC Power Connector for Double Density Disk Drives 6.00 ALL ASSEMBLED - NOT A KIT DISK DRIVE SIGNAL CABLES CLOCK/CALENDAR FEATURES Single 5V*" Drive Cable Dual 5'/-" Drive Cable Quad 5'/-" Drive Cable Single 8" Drive Cable Dual 8" Drive Cable Quad 8" Drive Cable Please state type connector: card-edge or socket. 26 Pin Card-edge Connector to DB25S 2' long $19.00 $24.00 $29.00 $34.00 $24.00 $32.00 $40.00 4116 — 8/$30.00 (200 ns) 2708 — $6.00 2716 (5V) — $9.00 2732 — $25.00 2114L3 — 8/$28.00 12/24 Hr. Format Month-Day-Year Day of Week Leap Year Bit 4 Interrupts +-30 Sec. Adjust Battery Backup Simple to Program S-100 Clock A&T $150 Kit $100 Bare Bd. $ 60 Apple Clock A&T Kit Bare Bd. TRS-80 A&T Only $150 $100 $ 60 $150 WE ACCEPT MASTER CHARGE, VISA & AMERICAN EXPRESS LAX COMPUTER PRODUCTS 4728 Manhattan Beach Blvd. Lawndale, CA 90260 (213) 542-4505 Apple is a Trademark of Apple Computer Co. TRS80 is a Trademark of Tandy Corp. TERMS: Cash, checks, money orders, credit card. C.O.D. under $100.00 add $2.00 C.O.D. charge. Minimum shipping & handling charge $3.00. Prices subject to change without notice. All sales in American dollars only. 378 BYTE April 1981 Circle 284 on inquiry card. 6502, Z80, 8080 AND 8085 USERS JOHN BELL ENGINEERING'S 6502 AND Z80 MICROCOMPUTERS ARE DEDICATED COM- PUTERS DESIGNED FOR CONTROL FUNCTIONS. THESE BOARDS FEATURE: • 2048 BYTES EPROM • 1024 BYTES RAM • ALL BOARDS INCLUDE COMPLETE DOCUMENTA TION • 50 PIN CONNECTOR IN- CLUDED IN KITS AND ASSEMBLED UNITS • 2716 AVAILABLE SEPARATELY JOHN BELL ENGINEERING'S 6502 MICROCOMPUTER, 2716 EPROM PROGRAM- MER AND APPLE II PARALLEL INTERFACE PLUS THE APPLE II MICROCOMPUTER — A COMPLETE DEVELOPMENT SYSTEM. 6502 MICROCOMPUTER FEATURES: • 1024 BYTES RAM • 2048 BYTES EPROM • USES ONE 6522 VIA (DOC. INCL) • 2 8 BIT BIDIRECTIONAL I/O PORTS • 2 16 BIT PROGRAMMABLE TIMER/ COUNTERS • SERIAL DATA PORT • LATCHED I/O WITH HANDSHAKING LOGIC • TTL AND CMOS COMPATIBLE 80-153 ASSEMBLED $ 1 1 0.95 BARE BOARD $24.95 KIT $ 89.95 USE YOUR 6502 OR Z80 MICROCOMPUTER TO CONTROL EVERYTHING! JOHN BELL ENGINEERING'S NEW Z80 MICROCOMPUTER FEATURES: • Z80 CPU SOFTWARE COMPATIBLE WITH Z80, 8080 AND 8085 MICROPROCESSORS • 2048 BYTES EPROM • 1024 BYTES RAM • SINGLE 5V POWER SUPPLY AT 300MA •CLOCK FREQUENCY IS 2MHZ, RC CON- TROLLED » Z80 PIO (DOC. INCL) • 2 8 BIT BIDIRECTIONAL I/O PORTS • LATCHED I/O WITH HANDSHAKING LOGIC • TTL AND CMOS COMPATIBLE 80-280 BARE BOARD ASSEMBLED $129.95 $29.95 KIT $119.95 • YOUR HOME SECURITY SYSTEM • HEAT CONTROL • LIGHT CONTROL • SOLAR HEATING AND POWER SYSTEMS • AUTOMATIC CONTROL OF TAPE RECORDERS • TRAFFIC LIGHT CONTROL • IRRIGATION SYSTEMS • AUTOMATIC CONTROL OF VIDEO RECORDERS • ROBOT CONTROL • AUTOMATIC DIALER • AUTOMATED SLIDE SHOW CONTROL • COMMUNICATION SYSTEMS FOR THE DISABLED • THE WORLD John Bell Eivgiiveeriivg VISA ALL PRODUCTS ARE AVAILABLE FROM: JOHN BELL ENGINEERING P.O. BOX 338 • REDWOOD CITY, CA 94064 • (415)367-1137 "SEND FOR OUR COMPLETE CATALOG! ADD 6% SALES TAX IN CALIFORNIA. ADD 5% FOR SHIPPING AND HANDLING. MASTER CHARQE Circle 285 on inquiry card. BYTE April 1981 379 Circle 286 on inquiry card. CALL TOLL FREE 228 4097 Call Toll Free For "Unbelievable" Low Low Prices On These Lines: APPLE — ATARI — BASE 2 CENTRONICS COMMODORE — DC HAYES HAZELTINE — LEEDEX MACROTRONICS — MAXELL MOUNTAIN HARDWARE NORTH STAR — PANASONIC SANYO — SYNCOM TOUR CUCTftONICS lf^LA>7Ci®PIMi 1840 "O" Street Lincoln, Nebraska 68508 In Nebraska Call (402) 476-7331 | MicroCompEquip 1 DISCOUNTS & DEALER OVERSTOCKS ALL ITEMS BELOW SOLD AS IS - NO RETURNS / NO REPAIRS CALL FOR AVAILABILITY: LIMITED QUANTITIES NEW EQUIPMENT Sell For List Price Polymorphic Systems A.l. Cybernetics Speechboard 260.00 380.00 8K Assembled 8K Memory Board 289.00 225.00 385.00 300.00 CALL FOR Anadez 40 Column Printer 641.00 855.00 Poly KBD 169.00 225.00 OUR LOW PRICES Base 2 8K Memory Board Assembled 211.00 262.00 8813 2880.00 3250.00 Commodore 2001-8 8K PET 550.00 795.00 System 378.00 525.00 FOR THE FOLLOWING Craig M-100 Translaler 122.00 199.95 88-System 2 529.00 735.00 Dajen Cassette Interlace 88.00 120.00 System 12 Kit 846.00 1128.00 MANUFACTURERS : Dynabyte Naked Terminal 245.00 350.00 System 6 1134.00 1575.00 Digital Systems Dual 8" Single Density 2293.00 2732.00 Video Card 210.00 280.00 Dutronics Poly Z-80 Upgrade Kit 123.00 169.95 Processor Tech APPLE Dutronics Jmsai Z-80 Upgrade Kit 116.00 159.95 Cuts BD Assembled 139.00 199.00 Eclectic Corp. Su" ^rchip for Apple II 75.00 95.00 8K Dynamic Ram 175.00 250.00 ATARI Fidelity Electronics Ltd. 16K Dynamic Ram 300.00 429.00 Level 1 Chess Challenger 120.00 75.00 64 K Dynamic Ram 878.00 1350.00 CROMEMCO Level 4 Checker Challenger 100.00 115.00 Extended Basic Cassette 21.00 45.00 Level 2 Checker Challenger George Riak Inc. Pet Keyboard 40.00 176.00 40.00 250.00 SOL 20 W/O Memory System II Kit 1270.00 1262.00 1895.00 1905.00 VECTOR GRAPHIC Imsai CPU Board 125.00 175.00 Panasonic Monitor 143.00 210.00 Icom Micro Peripherals 5" Disk Drive 821.00 1095.00 SD Sales 32K Dynamic Ram Board Kit 332.00 475.00 Intertec Data Intertube Terminal Kent Moore 8K RAM 450NS 595.00 148.00 874.00 197.50 Solid State Music 16K Static Ram Board Kit Southwest Technical (SWTPC) 300.00 325.00 Kent Moore Alpha Display Module Mountain Hardware 80.25 107.00 MF-68 Dual 5" Floppy Graphics Terminal 796.00 79.00 995.00 98.50 MicroCompEquip AC Control Apple 132.00 189.00 Technical Design Labi. (TDL-Xitan) PO BOX 195 AC Remote 95.00 149.00 I/O board - SMB-II 257.00 395.00 S-100 AC Control Kit 104.00 149.00 32L Series K Memory Board 559.00 799.00 CROWNSVILLE, MD 21032 AC Remote Kit 67.00 99.00 Fortran IV Ser.37 279.00 349.00 AC Control- Apple Kit Micromation Dual Memorez 8" disk drive 104.00 1467.00 145.00 1990.00 Fortran IV Ser.41 Xitan Alpha 1.5 279.00 823.00 349.00 1138.00 Micromation Dual Density disk controller Card MS Corp. Apple PR-40 Interlace 310.00 87.00 500.00 87.00 Xitan Alpha 1 Xitan Alpha 3 576.00 854.00 769.00 1181.00 VISA / MC / CHECK National Multiplex Digital Cassette Recorder 150.00 200.00 Xitan Alpha 1.5 571.00 868.00 Novation 1200 Baud Modem (4202T) Radio Shack TRS-80 Disk Drive 274.00 399.00 375.00 499.00 Video Board Technico Super Starter Assembled 277.00 293.00 369.00 300.00 PHONE ORDERS: TRS-80 16K Computer 479.00 599.00 Technico Super Starter Kit 199.00 299.00 (301) 261-1859 TRS-80 Expansion Interlace 239.00 299.00 Trace Elec. 32K RAM Board Assem 599.00 999.00 380 BYTE April 1981 Circle 287 on inquiry card. 1858 Evergreen Street, Duarte, DIGITAL INC. INSULATION DISPLACEMENT SOCKETS RIGHT ANGLE HEADERS ' « '£. 1 S 1 * 1; Pins 10 20 26 34 40 50 IDH10SR -80 IDH20SR1-25 IDH26SR 1-85 IDS34SR 2.15 IOH40SR 2.50 IDH50SR 3.15 EJECTOR EARS .25 IDH10WR 1.75 IDH20WR 2.75 IDH26WR 3.60 IDH34WR 4.15 IDH40WR 4.90 IDH50WR 6.15 EACH 25 PIN "D" CONNECTORS .•--■: m> Slyl. Part • SOLDER STYLE Male DB25P .2.25 Female DB255 3.00 Hood DB25C 1.10 INSULATION DISPLACEMENT Male IDC25P 4.95 Female IDC255 5.25 Hood IDC25C 1.35 CARD EDGE CONNECTORS m Pins Part No. 10 IDE10 3.25 20 IDE20 3.50 26 IDE26 4.05 34 IDE34 4.85 40 IDE40 5.65 50 IDE50 5.90 SOCKETS Ptna Part No. 10 IDS10 20 26 34 40 50 IDS20 IDS26 IDS34 IDS40 IDS50 1.25 2.02 2.65 3.50 4.05 5.06 Slain Rail*) .25 .25 .25 .25 .25 .25 Conductors: Solid Color Color Coded 10 14 16 20 24 26 34 40 50 10 ft. 2.90 3.40 3.70 4.40 5.00 5.40 6.80 7.80 9.50 toon. 17.00 23.80 27.20 34.00 40.80 44.20 57.80 68.00 85.00 ton. 4.00 5.00 5.60 7.00 8.00 8.60 11.00 13.00 16.00 toon. 30.00 42.00 48.00 60.00 72.00 78.00 102.00 120.00 150.00 CABLE PLUGS ^ - T^^^^^^T^ Pins Part No. 14 IDP14 1.25 16 IDP16 1.40 24 IDP24 2.25 40 IDP40 3.65 WIRE WRAP WIRE WIRE KITS Length 100/Bag 500/Bag 1K/Bag Length 100/Bag 500/Bag 1K/Bag Kit No. 1 $9.95 Kit No. 3 $32.95 2.5" $1.25 $3.58 $ 6.19 3.0" 1.30 3.86 6.78 3.5" 1.37 4.15 7.37 4.0" 1.42 4.44 7.94 4.5" 1.48 4.74 8.54 5.0" 1.54 5.04 9.13 5.5" 1.58 5.38 9.72 6.0" 1.65 5.66 10.31 6.5" $1.92 $6.44 $11.81 7.0" 1.99 6.76 12.44 7.5" 2.08 7.07 13.09 8.0" 2.14 7.38 13.73 8.5" 2.18 7.69 14.36 9.0" 2.24 8.11 15.01 9.5" 2.30 8.32 15.65 10.0" 2.39 8.71 16.28 250 250 100 3" 3'/ 2 " 4" 100 100 100 4'/ 2 ' 5" 6" 500 2'/2' 500 3" 500 3V4' 500 4" 500 4'/2" 500 5" 500 5'/2" 500 6" Kit No. 2 $24.95 Kit No. 4 $59.95 250 500 500 500 250 2'/2" 3" 3Vt" 4" 4'/4' 250 100 250 100 100 5" 5Vi" 6" 6'/2" 7" 1000 2'/2' 1000 3" 1000 3%" 1000 4" 1000 4'/2" 1000 5" 1000 5" 1000 6" Kynar precut wire. All lengths are ov Colors and lengths cannot be mixed fo Red, Blue, Black, Yellow, White, Gre erall, including 1" strip on each end. r quantity pricing. Choose from colors an, Orange, and Violet. ORDERING INFORMATION: • Orders under $25 include $2 handling • All prepaid orders shipped UPS Ppd. • Visa, MC & COD's charged shipping. • Ail prices good through cover date. • Most orders shipped same day. • Byte must be mentioned to get sale price. Write or call for 1981 catalog • IC Sockets • Vector Board & Pins • Bishop Drafting Aids • OK Tools • RN IDC Crimp Connectors "NEW" WIRE WRAP SOCKETS FEATURING A SELECTIVE PLATING METHOD THAT WILL SAVE YOU MONEY BY HAVING GOLD ONLY WHERE IT COUNTS. GOLD PLATED CONTACTS TIN PLATED TAILS 3 Level closed entry. RN Side Wipe contact design gives twice the contact area for high reliability. Size Quantitv/Tube Price ee.' Price/Tube B 52 .41 21.32 14 30 .47 14.10 16 26 .51 13.26 18 23 .70 16.10 20 21 .87 18.27 22 19 .94 17.86 24 17 .96 16.32 28 15 1.25 18.75 40 10 1.70 17.00 •FOR REFERENCE. MUST BE ORDERED IN TUBE QUANTITIES. Circle 288 on inquiry card. TOLL FREE ORDERING NUMBER 1 -(800,-423-7144 Z-80 FORTH $50.00 Fast, Interactive, and flexible lan- guage well suited for real time applica- tions. Full flg-FORTH" and FORTH-79 - vocabularies, plus extensions for access to all CP/M* ' functions. Uses standard CP/M compatible random access flies for screen storage. Eight-inch soft-sec- tored single density diskette includes: in- terpreter/compiler, line editor, screen editor, Z-80 assembler, decompiler, util- ities, and demonstration programs. 60 page user manual supplied. Requires Digital Research CP/M 2.x or MP/M 1.x. Price Includes tax and shipping by first class mail or UPS. Laboratory Microsystems 4147 Beethoven Street Los Angeles, CA 90066 * Forth Interest Group. * * CP/M Is a trademark of Digital Research, inc. COMPUTERS C1P SERIES II - $479 00 OUR price - $399.00 other OSI discounts available CALL NOW TOLL FREE 1-800-558-0870 COMPUTERS PLUS, INC. 2 749 S. 108th St. MILWAUKEE, Wl 53227 (414) 321-1770 IN WISCONSIN P~ QUARTZ CRYSTALS *«$ 1 , 3218 S 5.2428-B 9.9336 B 20OO0-B 36.2886-6 42.8518 8 468 126-8 I 1 535011 5.610 B 9.96408 B 2049B8B 363636-8 4287688 473768-B ' , , ' 1 000 A 5.7143-8 9.98960-B 22.1184-8 379628 B 429258 8 4 78336 B 4 | 1.8432-A 5.955-B I0OO0-B 226256 B 3B3768-B 42.962B-6 46O00 B , ' 1 . 1.8437-8 5.982-B ID2458-B 2E.3556-B 38.4448-6 4300086 48.3006-B | 1 ' 2.000 2.4576A 5.15030! 10.8255-8 27 000 -B 39.31 28 -B 43.1858 B 4B.B768-B . 1 1 . 2.500-A 6.297B0! 10.8386-8 27.0006 B 39.5038 B 43.25968 49.7O0E-B ' , , • 2.6657-8 64MB 1 1.1360 B 21 6506 B 39 66688 43.3338-8 49.7338-B ^ 1 2.9950-B 6.5536-B 11.155 8 28 4006-6 39.7536-B 4337088 496128-8 , ' 1 | 3.000-A 6.72530-1 112186-8 2B6276-B 39J768-B 43.4078 8 502505 B 1 | 3.067-8 6.75840-1 1 1.2890 B 28.7538 8 399628 8 43437BB SI0556-B ' . . 1 32MB 6.9003-6 1 1.4776 B 29.B758B 40.4448 8 43 44-18 8 51 31288 | | 3.276BA 7.0063-6 II.6566-B 29.9376-8 40.5928 B 43.5558-6 SI.7776B . f 1 . 3 500 II 7.0336-6 II.6B16-B 30O646-B 40.BI2B-B 43.62988 51.8506 8 ' | , ' 3.570-B 7.0916-8 12.440 B 30.36066 40.8336 11 43.6668-8 52.8128-B * ) 4.000 B 7.1636-8 14JI82-B 3002586 40.8758-3 43.77788 56.7506-B , ' * . 4.10434 7.2586-B 14.43D8-B 30S76BB 40B88B-B 43812B-B 60.6006B 1 | ' 4.M26B B.0OO-B 15000-B 31.4378-8 40.9258-8 438148 B 60.7508-8 ' , 1 4 4803 B 8.0556 B 15.4408 B 31.7538-8 41.0008-B 438518 B 66.7506-B { ' > 4.6103 8 8.1416-B 1 5.5066 B 3I9006B 4I.I666-B 438888-8 70.4006-B , 1 1 4.6503 B 8.1818-8 16.OO0-B 32.000-8 41.3768-8 43.9258-8 75 0005 B | , ' ■! 8303-3 8.3303-B 18.3848 B 33.2006-B 41.9378 B 44.O008B 906338 8 1 . , 4.9 152-8 8.4996-B 17.2248 B 33.6258-8 4Z.00O8-8 44.0378 B 99.9668-B < 1 , 5.000-B 8.5766-8 17.2422-B 34.5558 8 42.5636-8 44.376BB 100 6668 B . 1 | 5.06B8-B 8.6056-B IBOOO-B 34.7538-B 42.6268 8 44777BB 101.4666-6 ' , , ' 5.1203-B B.9606-B 184320 B 34.9776 8 -12.7005 8 45.1256-8 I03O668-B i 1 5.IB50-B 8.9906-B 19.4690 B 359256 B 42.7538 B 46.3006 B 1 03.4668 B , ' 4 . 5.1B56 8 9.4720B-B 19.7508 B 360008 4281438 46.70068 I04991B-B f < ALL A - .2.99 ALL B -11.99 OR MORE DEDUCT 5== ' | ADD SI. 00 SHIPPING CAL RES. ADD 6% SALES TAX FREE OSCILLATOR SCHEMATICS WITH ANY ORDER l| QUALITY COMPUTER PARTS |l 1 P.O BOX 743 / CHATSWORTH, CA 91 31 1 I Circle 341 on inquiry card. Circle 342 on inquiry card. Circle 343 on inquiry card. □(TiPUTLF? CDIhPDnETS LUQUR Q.T. AND GODBOUT COMPONENTS FROM SLUDER Assembled & Tested List 2 floppy 6JXS»Jlom 275 Gooaouf compupro phoducts assembled s tested INTERFACE!) 1 or !AIT 24 :iv r ,r[HM,r-Pon:ii«;c:c:. Serial etc 395 COMPLETE WOHD PROCESSING AND ACCOUNTING PACKAGE QT Syst8mComnulal 89W CALL OR WniTEFORC D ITEMS NOT LISTED an Cnochs, or Poslal Mor IKjotSOO. ANDSIiOOonSySlom^ Calilopnia F*n3iUrri1r.ii:l!i t"-i Salcl All Pi:tu^ Ltitijucl luClianoeWiinoijl Nolice f REE ACCOUNTING PACKAGE TO END USERS ON O T. SYSTEMS ■ PQ BQ* RBI • iVE5TTt-\ir\srE.R u.f\ qaJuQl — 71 H BRS 17Mb CP/M 68XX CROSS-SOFTWARE including source code in "C" ASSEMBLER FEATURES: J 2-pass absolute assembly ) Full instruction set, Motorola-compatible S Free-format input ^Unlimited length labels >Arithmetic expressions in operands ) Sorted symbol table output > Intel format hex output (PACKAGE A6800. . . MC6800/MC6802/MC6808 I PACKAGE A6801 MC6801/MC6803 1 PACKAGE A6809 MC6809 18" soft-sectored disk format, w/manual . . . S100.00 ■ 5" North Star disk format, w/manual S100.00 J Manual and listing alone S 85.00 (Wisconsin residents please add 4% tax) Introl corp< 647 w. Virginia St. visa and Milwaukee, Wl 53204 Master Charge (414) 276-2937 Accepted :■#*#»#»**■ ***** ••COMPUTER SURPLUS** ******************* Used micro computer systems 100% functional, $600 to $1500. Video terminals & keyboards, $50 to $700. Stringy floppy units-brand new, $300. All the above with documen- tation. Computer cabinets, 19" rack, $50 to $100. Power supplies, capa- citors, ribbon cable, cooling fans, misc. components & hardware. Also deal in IBM & Univac. CALL VIC CLOUGH at (216) 473-0866 DATA HARDWARE 701 Beta Dr. #4 Cleveland Ohio 44143 ************************ DEALERS WELCOME Circle 344 on inquiry card. Circle 345 on Inquiry card. Circle 346 on inquiry card. O Dysan ^CORPORATION Solve your disc problems, buy 100% surface tested Dysan diskettes. AD orders shipped from stock, within 24 hours. Call toll FREE (800) 235-4137 for prices and information. Visa and Master Card accepted. All orders sent postage paid. PACIFIC EXCHANGES 100 Foothill Blvd. San Luis Obispo, CA 93401. (InCal. call (805) 543-1037.) Pascal and C for hire Experience in: □ systems software □ real time applications □ business applications □ scientific applications □ data reduction Mc Henry Associates P.O. Box 2700 Huntington Beach, CA 92647 (714) 962-6019 CONVERT ANY TV TO A HIGH QUALITY MONITOR - *» - H i CH DUAL 1 TY TTTTTTT V V T y V T V V T HOD -- KITS • • • • • Hot Chassis or Transformer sets* 64-80 characters per line By-passes tuner & I.F. Normal viewing unaffected Safe— Easy kit installation ACVM Hi-resolution $34.95 ppc Referenced to neutral 1. V.A.M.P. INC. Box 29315, Los Angeles, CA 90029 Calif. Residents add 6% Sales Tax Circle 347 on inquiry card. Circle 348 on Inquiry card. Circle 349 on Inquiry card. m CROPROCiSSOi RS UPPORT I.C'S WE GUARANTEE FACTORY PRIME PARTS We are going to become the largest supplier of prime MEC 16Kx1 DYNAMIC RAM 200 N.S. microprocessor support I.C.'S. We guarantee that our I.C.'S These are prime 41 1 6's from one of the best are purchased from manufacturer authorized distributors. MOS RAM manufacturers in the world. This is the only way to deliver prime parts at the lowest 4116 200ns possible prices. Dur committment is to offer the best price and the fastest delivery to our customer. We give many 8 for $25.00 32 for 96.00 thanks to our va ued customers who have helped us grow. Only prepaid orders on this special. 8080A CPU 4.95 2708 EPROM 1Kx8 4.95 NEC 1Kx4 STATIC RAM 250 N.S. 8085A CPU 8.95 2716 EPROM 2Kx8 8.95 These are prime low power static ram's NEC 8086 CPU 99.95 2732 EPROM 4Kx8 21.00 for the finest in MOS MEMORY. 8088 CPU 44.95 4118 STATIC 1Kx8 15.00 2114L 250ns Z-80 CPU 10.50 4164 200ns 64Kx1 Call 8 for $25.00 32 for $96.00 Z-80A CPU 12.95 Z80B CPU 21.00 Only prepaid orders on this special. Z80-P10 7.75 8289 49.95 4050 .69 4531 .99 74C925 6.95 74LS107 .45 74LS244 1.95 Z80A-P10 9.75 4000 .35 4051 1.10 4532 1.25 74LS00 .35 74LS109 .45 74LS245 4.95 Z80-CTC 7.75 4001 .35 4052 1.10 4539 .99 74LS01 .28 74LS112 .49 74LS247 1.10 Z80ACTC 9.75 4002 .35 4053 1.10 4543 1.99 74LS02 .28 74LS122 .55 74LS248 1.10 Z80-DMA 22.25 4006 1.39 4055 3.95 4553 3.50 74LS03 .28 74LS123 1.19 74LS249 1.69 Z80A-DMA 27.75 4007 .29 4056 2.95 4555 .75 74LS04 .39 74LS125 1.35 74LS251 1.79 Z80-S10/0 24.95 4008 1.39 4059 9.95 4556 .75 74LS05 .28 74LS126 .89 74LS253 .98 Z80A-S10/0 29.95 4009 .49 4060 1.39 4581 1.99 74LS08 .39 74LS132 .79 74LS257 .98 Z80-S10/1 24.95 4010 .49 4066 .75 4582 1.01 74LS09 .39 74LS136 .59 74LS258 .98 Z80A-S10/1 29.95 4011 .35 4068 .35 4584 .55 74LS10 .28 74LS138 .89 74LS259 2.95 Z80-S10/2 24.95 4012 .29 4069 .35 4585 .99 74LS11 .39 74LS139 .89 74LS260 .69 Z80A-S10/2 29.95 4013 .49 4070 .49 4702 9.95 74LS12 .39 74LS145 1.25 74LS261 2.49 3205 3.45 4014 1.39 4071 .35 74C00 .39 74LS13 .47 74LS148 1.49 74LS266 .59 3242 10.00 4015 1.15 4072 .35 74C02 .39 74LS14 1.25 74LS151 .79 74LS273 1.75 8155 11.25 4016 .59 4073 .35 74C04 .39 74LS15 .39 74LS153 .79 74LS275 4.40 8185 29.95 4017 1.19 4075 .35 74C08 .49 74LS20 .26 74LS155 1.19 74LS279 .59 8185-2 39.95 4018 .99 4076 1.29 74C10 .49 74LS21 .38 74LS156 .99 74LS283 1.10 8202 45.00 4019 .49 4078 .35 74C14 1.65 74LS22 .38 74LS157 .99 74LS290 1.29 8205 3.45 4020 1.19 4081 .35 74C20 .39 74LS26 .39 74LS158 .75 74LS293 1.95 8212 2.00 4021 1.19 4082 .35 74C30 .39 74LS27 .39 74LS160 .98 74LS295 1.10 8214 3.95 4022 1.15 4085 1.95 74C32 .99 74LS28 .39 74LS161 1.15 74LS298 1.29 8216 1.85 4023 .38 4086 .79 74C42 1.85 74LS30 .26 74LS162 .98 74LS324 1.75 8224 2.65 4024 .79 4093 .99 74C48 2.39 74LS32 .39 74LS163 .98 74LS347 1.95 8226 1.85 4025 .38 4099 2.25 74C73 .85 74LS37 .79 74LS164 1.19 74LS348 1.95 8228 5.00 4026 2.50 4104 1.99 74C74 .85 74LS38 .39 74LS165 .89 74LS352 1.65 8238 5.45 4027 .65 4501 .39 74C85 2.49 74LS42 .79 74LS166 2.49 74LS353 1.65 8243 4.65 4028 .85 4502 1.65 74C89 4.95 74LS47 .79 74LS170 1.99 74LS363 1.49 8251A 5.55 4029 1.29 4503 .69 74C90 1.85 74LS48 .79 74LS173 .89 74LS365 .99 8253 9.85 4030 .45 4505 8.95 74C93 1.85 74LS51 .26 74LS174 .99 74LS366 .99 8255A 5.40 4031 3.25 4506 .75 74C95 1.85 74LS54 .35 74LS175 .99 74LS367 .73 8255A-5 5.40 4032 2.15 4507 .95 74C107 1.19 74LS55 .35 74LS181 2.20 74LS368 .73 8257 9.25 4033 2.15 4508 3.95 74C151 2.49 74LS73 .45 74LS190 1.15 74LS373 2.75 8257-5 9.25 4034 3.25 4510 1.39 74C154 3.50 74LS74 .59 74LS191 1.15 74LS374 2.75 8259A 7.30 4035 .95 4511 1.39 74C157 2.10 74LS75 .68 74LS192 .98 74LS375 .69 8271 60.00 4037 1.95 4512 1.39 74C160 2.39 74LS76 .45 74LS193 .98 74LS377 1.95 8275 32.95 4040 1.29 4514 3.95 74C161 2.30 74LS78 .65 74LS194 1.15 74LS385 1.95 8279 10.80 4041 1.25 4515 3.95 74163 2.39 74LS83 .99 74LS195 .95 74LS386 .65 8279-5 10.80 4042 .95 4516 1.69 74164 2.39 74LS85 1.19 74LS196 .89 74LS390 1.95 8282 6.70 4043 .85 4519 .99 74173 2.59 74LS86 .45 74LS197 .89 74LS393 1.95 8283 6.70 4044 .85 4520 1.39 74174 2.75 74LS90 .75 74LS221 . 1.49 74LS395 1.70 8284 5.85 4046 1.75 4522 .99 74C175 2.75 74LS92 .75 74LS240 1.95 74LS399 2.95 8286 6.70 4047 1.25 4526 1.15 74C192 2.39 74LS93 .75 74LS241 1.90 74LS424 2.95 8287 6.70 4048 .99 4527 1.75 74C193 2.39 74LS95 .88 74LS242 1.95 74LS668 1.75 8288 25.40 4049 .69 4528 .99 74C195 2.39 74LS96 .98 74LS243 1.95 74LS670 2.29 MAIL ORDERS SHOULD BE SENT TO: HANLEY ENGINEERING P.O. Bo x 21432 Seattle, Washington 98111 RETAIL STORE Telepho ne Orders & Inquiries (206) 453-0792 1644 116th NORTHEAST Minimu m Order $10.00 Add $3.00 Shipping BELLEVUE, WASHINGTON 98005 FOR T HE FINEST IN MICROF >RO< ZESSOR SUPPORT I.C s Circle 291 on inquiry card. BYTE April 1981 383 $94.20* Single Board Computer ► ortcs. nuKlet MCLi i 6800 MPU, serial I/O. parallel I/O, RAM, EROM, 44-pin AW x 6 V PCB EXPANSION MODULES RAM, ROM, CMOS RAM/battery, analog I/O, serial I/O, parallel I/O. counter/ timer, 488 GPIB, EROM programmer, power tail detect/power on reset IVINTKK Circle 292 on Inquiry card. ISIPERLETTERJ Is For SuperBrain' People! Now, owners and operators of Intertec SuperBrain computers around the world have a special newsletter to call their own! Superletter is packed each month with important technical news, accessory ideas, and CP/M software designs for the SuperBrain. Regular monthly features include Technical Corner, Q & A Forum, Intertec Factory News, Guest Interview, and Super Classifieds. For subscription info and ad rates, contact: SIPERLETTER Abrams Creative Services P.O. Box 3121 Beverly Hilts, CA 90212 (213)277-2410 MULTIPLE TERMINALS WITH CP/M®! Irvine Computer's NEW Model 100 Transaction Multiplexer lets you construct CP/M®-based, multi-terminal, transaction-oriented applications without- requiring additional system memory, serial interfaces, or a multi-user operating system! The Model 100 connects to your computer in place of your existing RS-232 console terminal. Up to seven (7) RS-232 terminal devices can then be connected to the Model 100. When the computer is busy, the Model 100 buffers all terminal input data until the application program asks for it. NO CP/M® mods, hardware mods, nor assembly- language code is required. Applications can be written in high-level languages. Loaded with features! S1495, quantity one, F.O.B. Costa Mesa, CA. Limited manufacturer's warranty. For more information, call or write: EASTERN U.S. AND FOREIGN: Wright Marketing Company, Ltd. 19104 Rhodes Way Gaithersburg, MD 20760 (301)840-1928 WESTERN U.S.: Irvine Computer Corporation (mfgr.) 3001 Red Hill Avenue, 6-103 Costa Mesa, CA 92626 (714) 557-5292 CP/M® is a registered trademark of Digital Research. Circle 293 on Inquiry card. Circle 294 on inquiry card. Write for FREE sample or tend $2.95 for a package of 10 holders plus S .75 for shipping and handling. FILING SYSTEM FOR COMPUTER DISKETTES A non-glare clearplis page hiving two pockets on one side to house one 8" diskette plus a top pocket to store in index card to record disk data. The pages are three-hole punch- ed for convenient and economical storage in standard three-ring binders. C|| 1 aiMINEtt INFORMATION : ttrrmn BIS. INC.. P.O. BOX 969. BRENTWOOD. TN 37027 • (615) 373-Z3U ATARI OWNERS SCREEN PRINT INTERFACE Obtain hardcopy of any screen image (graphics and / or text) on either a TRENDC0M 200 or IDS 440 Paper Tiger printer. Simply attach the supplied parallel printer cable and load the software from cassette (moy be transferred to Disk). Obtain a ' 'picture" of the screen on your printer under direct (CTRL?) or program (XI0) control Works In all graphics / text modes as well as LPRINT and LIST "P;" . . _ _ Only $139 Parallel Printer Interlace tor the ATARI 400 / 800 Connects to controller jocks 3&4 works with BASIC / DOS / ASSEMBLER Three printer connectors available ATARI 400 I 800 TRENDCOM100/ 200 A4P-1 A8P-1 CENTRONICS 730 I 737 A4P-2 A8P-2 CENTRONICS 36 PIN' A4P-3 A8P-3 69. 95 CA sales add 6% tax MC / VISA accepted "Fits all other parallel Centronics plus Anodex. Base 2, Epson. Comprint and Microtek Order by part number, ATARI is a recognized trademark o( ATARI. Inc AMCROTOONLCS, inc. - 1 125 N. Golden State Blvd. I Suite G Turlock, CA 95380 (A) (209) 667-2888 / 634-8888 HEADERS 34 PIN HEADER 3M 3413-1003 St. 25 EA 40 PIN HEADER ALPHA SI.50EA 50 PIN HEADER 3M 3433-1002 SI. 75 EA 40 PIN CONNECTOR 3M 3417 $1.50 EACH 22/44 EDGE CONNECTOR TIN SOLDERTAIL .1S6'x .200" 7-17vdc S.S. BUZZER Sound output 70aa (a 20 cm $1.25 each FLAT LEVER HANDLE 'MINI TOGGLE 5 PDI RATED 6 AMPS (£0 !3S V I 4 ■ JO BUSHING |J SI 00 each 10 for $8 50 Litronix FRL-4403 ♦J FLASHER LED d,^,.,, ,,„,,„ with built in Hashing unit T 1 '. package pulse rata 3hi u 5v20ms. LARGE QUANTITIES AVAILABLE $1. 35eac.fr. 1Q(orS12.50 ALL CLKTROflKS CORP. 905 S. Vermont Ave. terms Los Angeles, Calif. 90006 ■ o.»«,i».. i ,m,„.,i (21 3) 380-8000 ■ Min otf»$«M» Mon.-Fri. Saturday '"" p ?™usa 9 AM ■ 5 PM 10 AM • 3 PM • Calil "•» ■«« 6 °'- • Prompt Shipping SEND FOR FREE CATALOG Circle 295 on Inquiry card. Circle 296 on Inquiry card. Circle 297 on Inquiry card. LISP Interpreter for the TRS-80* See the August, '79 issue of byte to find how easy it is to USE LISP. ■ Includes more than 30 FUNCTIONS flt PREDICATES. ■ Coded for high-speed operation. ■ Full arithmetic capability. ■ User's Manual. ■ Supplied on cassette for 1 6K- 64K LEVEL II. Send $50 in checkor money order to: Cyber Innovations World Trade Center P. O. BOX 58657 Dallas, Texas 75258 •trademark of Tandy Corporation LOWEST COST LIGHTNING, RFI, STATIC, AND TRANSIENT VOLTAGE PROTECTION SOLVES diBc drive errors memory loss intermittancies short lifetimes USED FOR small computers medical equipment stereos, tv's word processors "CIRCUIT-SAFE" 2 INDIVIDUALLY FILTERED BANKS OF 3 SOCKETS (6 TOTAL 3-PRONG SOCKETS) 1875 WATT MAX LOAD.... $26.95 ppd. try one for 15 dayal HORIZON. INC. COMPUTER PRODUCTS DIV, BOX 454 PALATINE. IL. 60067 ENCLOSING CHECK MONEY ORDE; VISA MASTERCHARGE(BANK NO. EXPIRES SIGNED ACCT. NO.. NAME A ATARI" COMPLETE LINE OF ATARI COMPUTER PRODUCTS 20-25% OFF Alari 800 wrth 16K $81 Atari B10 Disk Drive $460 Atari 400 with 8K $399 Alari 410 Cassette Player $69 Visicalc $1 70 Kurta Graphics Tablet $560 Ramcram 32K Modules (upgrade 400 or 800} $256 ALL ATARI SOFTWARE 20% OFF BIT BUCKET SOFTWARE FOR ATARI: Utilities Disk with Disassembler, Basic Renumberer, Character Generator, Cruncher Utility (requires 24K) $45 Games: Mastercode, Mr. Simon, City Bomber (each) $12.95 Hex, Cryptogram, Flying Saucers (each) $14.95 Any 3 Ot above $30.00. (specify disk or cassette) ALSO: Commodore Pet at Similar Savings PLUS: Centronics, NEC. Zenith, Intertec, and More! ^ The Bit Bucket fp tfflr Hardware. Software. Consulting '%qW 168 North Beacon Streel 'fcjlL .P.O Box 365 Y~Tl Newlon Highlands. MA 02161 ^— J Phone:(617)783 3144 Circle 298 on Inquiry card. Circle 299 on Inquiry card. Circle 300 on Inquiry card. DOWN-TO-EARTH PRICES ON OUT-OF-THIS-WORLD PERSONAL COMPUTERS AND COMPONENTS. Look at this! Ohio Scientific Superboard II • It's the first complete computer system on a board. • Superboard II uses the ultra powerful 6502 Microprocessor • 8K Microsoft BASIC-in-ROM • 4K static RAM on board, expandable to SK • Full 53-key keyboard, with upper and lower case. Plus user expandability. • Video interface and audio cassette interface. The Ohio Scientific Superboard II at $299 — in today's economy — has got to be the best buy by far. It will entertain you with spectacular graphics made possible by its ultra high resolution graphics and super fast BASIC. It will help you in school or industry, as an ultra powerful scientific calculator. Advanced scientific functions and a built-in "immediate" mode allow you to solve complex problems without programming. The Superboard II can be expanded economically, for business uses, or to remotely control your home appliances and security. Even communicate with other computers. Read what's been written about Superboard II: "We heartily recommend Super- board II for the beginner who wants to get into microcomputers with a minimum cost. A real computer with full expandability." —POPULAR ELECTRONICS, MARCH 1 979 "The Superboard II is an excellent choice for the personal computer enthusiast on a budget. 11 —BYTE, MAY 1 979 Look at these easy hardware prices: 610 Board For use with Superboard II and Challenger 1 P. 8K static RAM. Expandable to 24K or 32K system total. Accepts up to two mini-floppy disk drives. Requires + 5V @4.5 amps. S 298 Mini-Floppy Disk Drive Includes Ohio Scientific's PICO DOS software and connector cable. Compatible with 610 expander board. Requires + 1 2V @1 .5 amps and +5V @ 0.7 amps. [Power supply S. cabinet not included.] 299 630 Board Contact us for important details. 229 AC-3P 12" combination black and white TV/video monitor. 159 4KP 4K RAM chip set. 79 PS-005 5V 4.5 amp power supply for Superboard II. 45 P8-003 1 2V power supply for mini-floppies. 45 PF Modulator Battery powered UHF Unit. 35 CS-900B Metal case for single floppy disk drive and power supply. [While stock lasts.] 49 AC-12P Wireless remote control system. Includes control console, two lamp modules and two appliance modules, for use with 630 board. 175 AC-17P Home security system. Includes console, fire detector, window protection devices and door unit for use with 630 board. 249 C1P Sams C1 P Service manual 8 C4P Sams C4P Service manual 16 C3 Sams Challenger III manual 40 Ohio Scientific and independent suppliers offer hundreds of programs for the Superboard II, in cassette and mini-floppy form. Freight Policies All orders of $100 or more are shipped freight prepaid. Orders of less than $1 00 please add $4.00 to cover shipping costs. Ohio residents add 5.5% Sales Tax. IBBB>Bi| r^MBkl Hours: Call Monday thru Friday. VISA (tflSfi, 8.00 AM to 5:00 PM E.O.T. I 1 I^^BJ TOLL FREE: 1-800-321-5B05 Guaranteed Shipment Cleveland Consumer Computers S. Components guarantees shipment of computer systems within 48 hours upon receipt of your order. Our failure to ship within 48 hours entitles you to 835 of software, FREE. TO Order: Or to get our free catalog CALL 1-800-321-5805 TOLL FREE. Charge your order to your VISA or MASTER CHARGE account. Ohio residents cail: [21 6) 464-8047. Or write, including your check or money order, to the address listed below. CLEVELAND CONSUMER COMPUTERS & COMPONENTS P.O. Box 46627 Cleveland, Ohio 44146 ■ SB SSI SSI BBS BBS ■ P.O. Box 46627 . COMPONENTS Cleveland, Ohio 44146 □ Superboard II $299. □ RF Modulator $35. D 61 Board $298. □ AC-3P 1 2 " BAA/ Monitor $1 59. □ Mini-Floppy Disk Drive $299. □ D1 P Sams Manual $8. [Attach separate sheet for other items.) NAME ADDRESS: CITY : I"! n rl o r> Cnrm> Cleveland consumer UlUCl fUl lie COMPUTERS SCOMPONI I I I I I I IUrders or less than anuu. please add $4.uu to cover shipping costs. Urders will be accepted fronrvU.S. and Canada only. All prices quoted are U.S., date of publication, standard UPS shipping FOB the factory. B _ . STATE: .ZIP:. MASTER CHARGE MONEY ORDER PHONE: Payment by: VISA Credit Card Account #_ Expires TOTAL CHARGED OR ENCLOSED $ rOhio Residents add 6.5% Sales Tax] Orders of less than £100. please add $4.00 to cover shipping costs. Orders will be accepted fronrvU.S. and Canada only. All prices quoted are U.S.. date of publication, standard UPS shipping FOB the factory. . Interbank #[Master Charge) Circle 301 on inquiry card. BYTE April 1981 385 Close Out Desk Top Computer This unit is a computerized Electronic Secre- tary. It keeps time. date, calendar, message, and meeting files. Originally sold thru a major mail order house for over $450. Technically, it's a 6507 MICRO, ROM, RAM, Panaplex Alpha Display, Ni-Cad battery, Power Supply. Keyboard, Wood and Aluminum Case with Schematic and operating instructions. Most of these Computers are warranty returns. We are offering Refurbished, like new, units for $99.95 and AS IS {most have minor problems) units for $44.95. Add $4.95 for shipping and handling. AH units are complete as described. All sales are final. California Residents add 6.5% sales tax. Send Payment with order or call our Order Line 408-272-2320 and use your MC or VISA card. Solid State Surplus P.O. Box 3241 8/San Jose, CA 95152 SOFTWARE DESIGN ENGINEER BSEE/BSCS. minimum 3 years programming experience. Real- time systems programming and software development for elec- tronic switches is a plus. Ex- perience with PASCAL or C or Assembly language required. Call collect or send resume to Ken- neth W. Cooper, Harris Corpora- tion, RF Communications Divi- sion, 1680 University Avenue, Rochester, NY 14610, (716) 244-5830, EXT 3356. I-LAJRRIS An Equal Opportunity Employer M/F ^TVTVl 8035 SYSTEMS A compact modular set of PC Boards for im- plementing test instruments, measurement and control systems, badge readers, data communications, data entry, games or home security systems. CPU Board. 8035. 2716 1K RAM, 40 I/O Lines SIO Board. 38251 A, RS232 Dr/Rec. 6 LEDs PIO Board. 2 8255 PIOs. KIT A&T $99 S125 99 125 99 125 2 or 3 Slot Mother Boards . . . Power Supply. 5V. 12V&-12V Diagnostic EPROM and Listing Bare Boards, Schematics and Parts Lists, each ... 50 55 65 40 S19.95 Boards are A" by 7". 80pms. 156 centersedge connector. Development Tools available on CPM. Make check payable to: SKP Electronics 221 1 Caper Tree Dr Justin. CA 92680 (7141832-1732 California residents add 6°o sales tax Please arid S3.00 tor shipping and handling Circle 302 on Inquiry card. Circle 304 on Inquiry card. Scotch' DISKETTES SAVE 40% complete list. 5%"Sgl. Dens. 26.70/10 Specify soft, 1 or 16 hard sectors 8"Sgl. Dens. 27.30/10 8"Dbl. Dens. 35.80/10 Specify soft or 32 hole hard Add $2.00 shipping - Michigan add 4% tax LYBEN COMPUTER SYSTEMS 27204 Harper Ave. St. Clair Shores, Ml 48081 Authorized Distributor Information Processing Products FLOPPY DISKS 8"& 5V4" OPUS-$26.00/boxoho 3M-$32.00/box of io iv/li-ir-i PO Box 5059 06460 (203)877-3610 We carry a full line of computer supplies Send for free cata log. VISA- MASTERCHARGE-CHECK BUY WHOLESALE! Sale thru 4/30/81 on Zenith/Heath Z-89 64K system, listing for $3045 Anyone may buy 1 for $2375 or 2 for $2284 each or 3 for $2193 each Gill or write for prices on other Zenith. North Star, and other Z-80 based computer svstenis, modules, peri- pherals, and supplies at New England's oldest independenl computer store. Computer Mart, Inc. 1395 Main Street Waltham, MA 02154 (617) 899-4540 Circle 305 on inquiry card. Circle 306 on Inquiry card. Circle 307 on Inquiry card. OKIDATA MICROLINE 80 PRINTERS 479.00 80 CPS • Up to 3 part copy '9X7 dot matrix • 80,132 columns - 64 shapes for graphs or charts • 6 or 8 lines per inch • Friction feed standard - Tractor feed optional • Quantity discounts available. Charge card orders add 3%. m American Business Computers 118 South Mill Street Pryor, OK 74361 sassa 918-825-4844 A classified ad magazine run by a computer... With AD-LINE" . a menu-driven computer program, one phone call will immediately compose and expertly index your ad. Prompts will insure inclusion of all pertinent details. AD-LINE* will answer all questions and take all subscription information. Use your terminal and any 300 baud coupler for instant communication with our computer. If you don't have a terminal to access AD-LINE* mail your ads to: PO Box 15642 Philadelphia, PA 19103 micrc CISICfl CMlSUTririTS 1 Bit through 32-Bit Machines We handle concept through production prototypes with complete documentation. HARDWARE - 916/723-1050 David Jenkins 7214 Springleof Court Cirrus Heights. CA 95610 SOFTWARE- 916/381-1717 Richard Lerseth - LEAPAC 0245 Mediterranean Way Sacramento. CA 95626 Circle 308 on Inquiry card. Circle 309 on Inquiry card. Circle 310 on Inquiry card. THE STAR MODEM From Livermore Data Systems RS232 MODEM IEEE 488 MODEM RS232 CCITT IEEE 488 CCITT SALE $135 SALE $245 $170 $280 STAR Modem is the price performance leader with a full 2 YEAR FACTORY WARRANTY. WE CARRY THE BLACK APPLE Belle, Howell apple computer inc. EBS Business System for PET/CBM Extremely comprehensive package for small business. Fully integrated inventory and accounts receivable system including invoices, packing slips, mail labels, statements, bank deposit slips, and 17 reports. Paper-Mate Word Processor $29.95 PET/CBM full featured 60 command system by Michael Riley. Uses either tape or disk and any printer. Includes in-text commands, floating cursor, scrolling, etc. FLEX-FILE Diti Bise lor CBM/PET $60 Random file handling system with Report Writer and Mail Label Handler. By Michael Riley KMMM Pascal lor PET $75 Subset of standard Pascal with true machine language translator for faster execution. 16K with tape or disk. EARL lor PET (disk file based) $65 Editor, Assembler, Relocates Linker to generate relocat- able object code. MIF0RTH+ for PET/CBM $65 A full-featured FORTH with extensions conforming to Forth Interest Group standards. Includes assembler, string process- ing capabilities, disk virtual memory multiple dimensioned arrays, floating point and integer processing. MIPLOT Intelligent Plotter by Watanabe Instruments (Dlglplot) SPECIAL $1145 Has all intelligent functions for producing graphs and drawings including 8 vector and 4 character commands. Solid and broken lines can be specified. Character gen- erator for alpha, numeric, and symbols. C haracters can be rotated in 4 orientations, and can be 1 6 sizes. Coordinate axes drawn by specifying graduation Interval and number of repetitions Parallel ASCII interface, 11x17 paper. SPECIALS EPSOM MX-aO Priitir Call EPSON MX-70 Mater Call STARWRITER Daisy Wheel Printer $1500 Centronics 737 Printer 790 NEC Spinwriter 2500 XYMEC Hl-Q 1000 Intelligent Daisy Wheel 2150 Leedex Video 100 12" Monitor 129 ZENITH DATA SYSTEMS Z1 9 Video Terminal (factory assera) 735 Z89 with 48K (factory assem.) 2150 SYM-1 209 SYM BAS-1 BASIC or RAE-1/2 Assembler 85 KTM-2/80 Synertek Video Board 349 Seawell Motherboard - 4K RAM 195 Seawell 16K Static RAM - KIM, SYM, AIM 320 6502 6502A 6520 PIA 6522 VIA 6532 7.45 8.40 5.15 6.45 7.90 2114-L200 ns RAM 2716 EPROM(5volt) TMS 2532 EPROM 4116-200 H RAM S-100 Wire Wrap 10/6.95 50/6.55 100/6.15 10/7.95 50/7.35 100/6.90 10/4.90 50/4.45 100/4.15 10/6.10 50/5.75 100/5.45 10/7.40 50/7.00 100/6.60 3.75 20/3.50 100/3.25 9.90 5/9.45 10/8.90 23.50 6 fir 29.00 2.65 commodore CBM-PET SPECIALS ,r Pascal NorlhWord General Ledge; COD CASH IN ADVANCE VISA/ MASTER CHARGE' •ADD 4 PERCENT ON CHARGE ORDERS CUSTOM BUSINESS COMPUTERS 103 ATLANTIC AVENUE, LYNBROOK. NEW YORK 1 1563»(516)8873340 list xref sort col print and more Fine Software Tools in C The Toolbox prints that missing source listing cross reference C programs alphabetize by all or part ot text line arrange text in columns on page paginates text (or hard copy All programs are in portable Whitesmith C xref and list are compatible with the compiler's error listing Title lines on list and print output includes the date on RT-11 systems Source code on 8" floppy and manual available immediately for $45 (lax and shipping included} Specify RT-11 or CP/M format The Toolsmith Dept. BYTE P. O. Box 22511 San Francisco, CA 94122 RT-11 is a trademark of Digital Equipment Corp CP/M is a trademark of Digital Research Circle 322 on inquiry card. Circle 323 on inquiry card. Circle 324 on inquiry card. SMARTNET -Automatic spooling and despooling. -Levels 1-15 of the hub computer are password protected. -No modifications needed to the BIOS or XI05. -Block data transfer with checksum. -Low memory requirements. -Complete source code provided. REQUIREMENTS -Hub comuuter must be running KP/K*. -imartnet requires CF/tf* 2.2, 20k of memory and at least one disk drive. - Dumbnet requires at least 16k of memory. Disk drives not needed. PRICE JKARTNET C 150. 00 DUHB.'ET 3 175.00 PURCHASE TOGETHER .3500.00 LIMMAR 541 Ingraham Ave. Calumet City, IL. 60409 "512-868-4 866 Ask for Mark * Trademark of Digital Research, SURPLUS ELECTRONICS ASCII ASCII TRS-80* COMPATIBLE, IBM SELECTRIC- BASED I/O TERMINAL with ASCII conversion installed: $645.00 Many Other Items Available: Tape Drives; Cable: Cassette Drives; Wire; Power Supplies (5 volt 35 amp, others); Displays; Cabinets; Transformers; Heat Sinks; Printers; Com- ponents. Send lor Free Catalog WORLDWIDE ELECTRONICS, INC. 130 Northeastern Blvd. Nashua, N.H. 03062 Phone orders accepted using VISA or MC Toll Free 1-800-258-1036 in NH 603-889-7661 'TRS-80 is a trademark of the Radio Shack Division of Tandy Corporation. MEMOREX Floppy Discs Lowest prices. WE WILL NOT BE UNDERSOLD!! Buy any quantity 1-1000. Visa Mastercharge accepted Call free (800)235-4137 for prices and information. All orders sent postage paid. PACIFIC EXCHANGES 100 Foothill Blvd San Luis Obispo. CA 93401 (In Cal. call (805)543-1037) Circle 325 on Inquiry card. Circle 326 on inquiry card. Circle 327 on Inquiry card. No TRS-80© Word processor is complete without PROOFREADER Let your TRS-80 proofread your SCRIPS1T, Electric Pencil or other documents. Proof- reader uses a 38,000 word dictionary and lists misspelled words on a file, screen, or printer. (Requires 32K, 1 disk. MODEL! ) $34.00 RATFOR Rational Fortran preprocessor allows struc- tured programming using Fortran. One of the best versions available, with full manual. (Requires Fortran, 48K, 2 disks, MODULI) $49.00 SOFT-TOOLS are professional quality soft- ware tools developed for the TRS-80 by a PhD in Computer Science. Versions for MODEL-III available soon. Order Postpaid: SOFT-TOOLS MHE Box 14 Tijeras, NM 87059 Know The Reasons Why The FORCE-80 is your "Best Buy." FORCE-80 The computer protector • Power dropout protection • Suppresses transient voltages • Suppresses RFI • Disc protection • Factory warranty • Satisfaction guaranteed • Direct from factory FORCE-80 Only $121.50 plus $5.00 shipping & handling Check, Mastercharge, Visa accepted (5% discount lor cash) ^^^m No C O D 's please ^^ — P&S Electronics, Inc. P.O. Box 23014 Dept. B Nashville, TN 37202 Allow 6-8 weeks for delivery. Add 14 days for personal checks. Double Side Disk Drives - a Disk Drive Subsystem with Dual Double Side Drives, Power Supply and Cable. Total Capa- city 2.4 M-Byte. Fully Assembled and Tested. Only t! 1 . Table Top Version $1 ,695.00 2. Rack Mount Version 1,695.00 3. Pair of Slides with Attachment 4. S100 Disk Controller (handles single & double density in 256, 512 & 1024 byte sectors, single & double side) 350.00 5. Double Side Disk Drives (1 .2 mb) 535.00 (Qume DT/8) Call Now (408)496-6910 OSM Computer Corporation 2364 Walsh Avenue Santa Clara, CA 95051 Circle 328 on inquiry card. Circle 329 on inquiry card. Circle 330 on Inquiry card. electronic components fffl^w TTL i%* One-Stop Component Center ( ™ ; This is a partial listing of over 500 items available from 500 authorized Jim-pak Distributors: 7400 2/.85 7402 2/.85 7404 2/.85 7406 2/1.19 7407 2/1.19 7408 2/.S9 7410 2/.85 7414 99 7417 2/1.10 7420 2/.85 7447 1.19 7474 69 7475 79 7476 69 7485 1.19 7486 2/1.19 7489 2.99 7490 85 7493 85 74100 2.25 74109 2/1.19 74121 69 74123 99 74150 1.95 74154 1.95 74157 99 74161 1.19 74164 1.59 74174 1.59 74175 1.49 74192 1.19 74193 1.19 74367 99 74393 1.95 POTENTIOMETERS 2 Watt @ 70°C 7/8" Slotted Shaft Linear Taper 1K 5K 10K 25K 50K 100K 1 Meg CMU . . $2.95 3/4 Watt @ 70°C 15 Turn Pot. Linear Taper 100n 500ft 1K 5K 10K 50K 100K 500K 1Meg 830P. .$1.79 ffi^ CMOS ^* 4000 4001 4002 4006 4009 4010 4011 4013 4016 4017 4018 4020 4023 4024 4027 .69 .69 .69 1.95 .89 .85 .69 .85 .85 1.49 1.49 2.19 .49 1.29 .89 4030 . . . . . . .79 4040 . . . . . . 1.95 4044 . . . . . . 1.39 4046 . . . . . . 2.49 4047 . . . . . . 2.75 4049 . . . . . . .89 4050 . . . . . . .89 4051 . . . . . . 1.95 4066 .. . . . . 1.19 4069 . . . . . . .79 4070 . . . . . . .79 4071 . . . . . . .79 4081 . . . . . . .69 4093 . . . . . . 1.19 4511 . . . . . . 1.95 CONNECTORS DB25P D-Subminiature Plug 3.95 DB25S D-Subminiature Socket 4.95 DB51226 Cover for DB25P/S 2.25 22/44SE P.C. Edge 2.95 UG88/U BNC Plug 2.19 UG89/U BNC Jack 3.95 UG175/U UHF Adapter .59 S0239 UHF Panel Recp. 1.49 PL258 UHF Adapter 1.95 PL259 UHF Plug 1.95 UG260/U BNC Plug 2.39 UG1094/U BNC Bulkhead Recp. 1.49 WW LINEAR ffiffi* LM301N. LM305H. LM307N. LM308N. LM309K. LM310N. LM311N. LM317T. LM318N. LM319N. LM320K-5 LM7905T LM7912T LM7915T LM323K. LM324N. LM337T . LM339N. .59 1.39 .75 1.19 2.25 2.69 1.49 2.29 2.95 2.95 2.25 1.75 1.75 1.75 5.95 1.29 2.29 1.29 LM7805T LM7812T LM7815T LM380N. LM384N. LM555N. LM556N. LM565N. LM566N. LM567N. LM723N. LM741N. LM1310N LM1458N LM1488N LM1489N LM1800N 76477 N. . 1.75 1.75 1.75 1.49 2.49 .69 1.49 1.95 1.95 1.79 .79 .65 2.95 .99 1.59 1.59 4.49 3.95 GRAB BAGS GB100 Cer. Caps. (100) 2.95 GB101 Mylar Caps. (60) 4.95 GB102 Electrolytic* (60) 4.95 GB103 Tantalums (40) 4.95 GB108 TTL IC's (50) 4.95 GB110 Asst. LEDs (100) 5.95 GB113 Trimmers (30) 4.95 GB116 Vsw Resist. (200) 2.95 GB117 V 2 W Resist. (200) 2.95 G8120 SlideSwitch(25) 3.95 GB123 Heat Sinks (30) 3.95 GB127 Transistors (100) 3.95 GB137 Chokes (50) 3.95 GB139 Term. Strips (40) 3.95 GB140 Spcr/Stndff(150) 2.95 GB141 Washers (200) 2.95 GB145 Lugs (100) 2.95 GB154 l&2w Resist. (100) 2.95 GB162 7-Seg.Dsplys.(50) 5.95 GB173 3/8" Pots. (100) 5.95 REGULATED POWER SUPPLY KIT Uses LM309K. Heat Sink _ provided. PC board con- struction. Provides a solid 1 amp (s> 5 volts. Can supply up to±5V, ±9Vand ±12Vwith JE205 Adapter. Includes compo- nents, hardware and instructions. 3y 2 "x5"x2"H JE200 $14.95 DESK TOP ENCLOSURES DTE-8 (Pictured) $31.95 DTE-11 (Pictured) 34.95 DTE-14 36.95 DTE-HK (Case for JE600) 47.95 DTE AK (Case for JE610) (Pictured) ... 52.95 JOYSTICKS JS-100K 100K Linear Taper Pots $5.49 JVC-40 40K (2) Video Controller 5.95 V TOOLS PCB-3 P.C. Board Vise $12.49 WS-150 5"WireStrip./Cut. (12-24AWG). . 3.99 SG-30 10" 110-120V30W Solder Iron. . 7.50 SG-TIP Replacement Tip for SG-30 S. Iron 1.25 WALL TRANSFORMERS AC250 DV9200 250mA 12VAC 200mA 9VAC (117V/60Hz). (117V/60Hz). $3.95 3.95 WW LS Schottky WW 74LS00 55 74LS109 79 74LS02 55 74LS123 .... 1.95 74LS04 69 74LS138 .... 1.49 74LS08 55 74LS139 .... 1.49 74LS10 55 74LS154 .... 2.49 74LS14 1.09 74LS157 .... 1.49 74LS30 55 74LS161 .... 1.79 74LS32 69 74LS174 .... 1.79 74LS38 69 74LS175 .... 1.79 74LS42 1.49 74LS192 .... 1.89 74LS47 1.49 74LS193 .... 1.89 74LS48 1.79 74LS221 .... 1.95 74LS73 79 74LS244 .... 2.49 74LS74 79 74LS245 .... 3.49 74LS75 99 74LS367 .... 1.29 74LS85 1.95 74LS374 .... 2.49 74LS90 1.09 81LS97 2.49 SOCKETS Low Profil 8 pin LP . 14 pin LP . 16 pin LP . 18 pin LP . 20 pin LP . 22 pin LP . 24 pin LP . 28 pin LP . 36 pin LP . 40 pin LP . e Wire Wrap 2/.59 14 pin WW tin .75 2/.69 14 pin WW gold 1.09 2/.79 16 pin WW tin .79 2/.89 16 pin WW gold 1.19 2/.99 24 pin WW gold 1.69 2/1.09 40 pin WW gold 2.75 .79 14 p. plug/cover 1.29 .82 16 p. plug/coverl.39 .99 24 p. plug/cover 1.95 1.19 Also, The Molex Line DIODES & TRANSISTORS IN751 . IN757 . IN1188. IN 3600. IN4001. IN4004. IN 4007. IN4148. IN4733. IN4734. IN4735. IN4742. IN4744. . 2/.59 . 2/.59 . 2.69 . 5/.99 . 4/.59 . 4/.69 . 4/. 79 .10/. 99 . 2/.69 . 2/.69 . 2/.S9 . 2/.69 . 2/.69 2N2219A. . . .2/1.19 2N2222A. . . . 2/.89 2N2907A. . . . 2/.89 2N3055 99 2N3772 2.25 2N3904 2/.69 2N3906 2/.69 2N4401 2/. 79 2N4403 2/. 79 2N5129 2/.69 2N5139 2/.69 2N5210 2/.79 2N5951 2/1.29 CAPACITORS Dipped Tantalum ELECTROLYTIC .lmfd@35V .47mfd@35V lmfd@35V 2.2mfd@25V 3.3mfd@25V 4.7mfd@25V 10mfd@25V 33mfd@25V 100V MYLAR .OOl-.Olmfd 4/.79 .022mfd 4/.89 .047mfd 4/.99 .lmfd 4/1.19 .22m fd 4/1.29 2/. 8 2/.89 2/.S9 2/1.09 2/1.19 2/1.39 1.19 3.95 lmfd@50V 4.7mfd@50V 10mfd@50V 22mfd@50V 47mfd@50V 100mfd@50V 220mfd@50V 1000mfd(°>25V 2200mfd@16V 50V CERAMIC 10pf-.022mfd 4/.59 .047mfd 4/.69 .lmfd 4/.79 3/.69 2/.59 2/.69 2/.79 2/.89 .59 .69 1.19 1.39 MICROPROCESSORS Z80A CPU (4MHz) 14.95 MC6800 8 Bit MPU 14.95 8080A CPU 7.95 8212 8 Bit I/O Port 3.95 8216 Bi-Directional Bus Driver 4.49 2513/2140 Character Generator 12.95 8T97 Tri-State Hex Buffer 2.25 AY-5-1013 30K Baud UART 6.95 AY-5-2376 88-Key Keyboard Encoder 13.95 2114-3 4K Static RAM (300ns) 9.49 MK4116 16K Dynamic RAM (250ns) 9.95 2708 8K EPROM 10.95 2716 16K EPROM (+5V) 19.95 12VDC AUTOMOTIVE/ INSTRUMENT CLOCK MODULE s ® © ® — a^' ^ .300 GREEN DISPLAY MA1003 $19.95 Circle 331 on inquiry card. BYTE April 1981 391 !! REAL TIME ! 1 1 The TIME MACHINE from ALPHA OMEGA COMPUTER SYSTEMS isn't just another digital clock chip surrounded by interface circuitry. It's an intelligent microcomputer based peripheral device. The TIME MACHINE communic itej with your computer via a serial I/O port at a user selectable data rate between 300 and 2400 baud. RS-232, RS-422, or current loop communication may be used. Battery protection against power loss is included. The TIME MACHINE automatically computes day ot the week and leap year. Buffered output oulses at one second, one minute, and one hour intervals are provided. Dimensions are 2.5 x 4."'5 x 7.5 inches. Batteries, power supply, and communication cable are included. Price Is only $450 single lot and quantity discounts are available. Dealer inquiries invited. Off the shelf delivery. ALPHA OMEGA COMPUTM I9STIMI , INC. P O Bo. T27 / Cdivalht. Cgon 07330 : 4AS D D£>US SHOP HERE AND (7 10 (MINIMUM ORDER $10.00) 7M « ABSOLUTELY the LOWEST PRICE EVER for a Hi Speed (300 NS) LO-LO Power 32K RAM. { 4K by 1 Chips are organized in Selectable Banks, * Extended Address Lines A16 - A17 * Phantom Line * 9 Regulators SCHOOLS DIP SWITCHES p os. prc 4 .88 5 .92 6 .95 7 .99 8 1.05 9 1.15 10 1.19 JK ' EX PINS PC WW 8 14 16 18 20 24 28 40 .10 .26 .13 .29 .16 .32 .18 .34 .22 .32 .34 .45 .38 .48 .50 .61 AMP - Need we say more? There is a dif- ference in sockets! These aren't the low- est prices you can find. But, if you've been"burned" before by bad connections in your computer, a few pennies for the best is worth it! RESISTORS .02 ea! (100 PACK) %W 1.0 4.7 6.8 10 15 22 27 33 47 68 75 100 150 220 330 470 680 1K 1.5K 2.2K 2.7K 3.3K 3.9K 4.7K 6.8 K 10K 12K 15K 18K 20K 22 K 24 K 27K 33 K 39 K 47 K 68 K 100K 220K 330K 470K 680 K 1M 1.5M 2.2M 4.7M 150K 10M WIRE WRAP WIRE Packed in 500 Lot Bundles (Length includes 2" x 1 Color - R, Bu, G, Y, 50 ft. $1.65- 100 ft. $3.00- 2.5-3.25 3.0-3.35 3.5-3.50 4.0-3.75 4.5-4.00 5.0-4.50 ' Strip) Bk, W 500 ft. $9.50 6.0-4.75 7.0-5.00 8.0-5.50 10.0-6.50 OK WIRE WRAP TOOL $5.95 ST21 ST22 ST23 ST24 ST25 ST26 6 Amps 125 VAC 7 Amps 30 VDC $1.25 ea. DPDT STANDARD TOGGLE (ON-NONE-ON) (ON-OFF-ON) (MOM ON-OFF-MOM ON) (ON-OFF-MOM ON) (ON-NONE-MOM-ON) (ON-ON-ON) HOBBIEST LM323K 5V 3A . REGULATOR $5.50 TAB MOUNT 7805 +5V 1A 7905 -5V 1A 7812 +12V 1A 7912 -12V 1A HEAT SINKS 49$ $1.25 ♦ GOLD ♦ S-100-CONNECTOR Tl or Better $2.50 $3.25 DIP PLUGS PART* PINS PRICE 08 DP 14DP 16DP 24DP 40DP 14 16 24 40 .40 .55 .58 .95 1.50 Socket and Dip Plug priced based on gold not exceeding $700 per ounce. CONNECTORS DUAL ROW .100 CARD EDGE PINS PRICE PINS PRICE 20 2.35 20 3.35 26 3.00 26 3.80 34 3.85 34 4.65 40 4.50 40 5.50 50 5.50 50 5.90 RIBBON - 20 to 34 @ 1 .00 ft. 40 & 50 @ 1.30 ft. CRIMPING 2.00 / CONNECTOR OEM'S Z-80-A $6.95 4MHZ Beastie with extra instructions! Z-80 SUPPORT CTC - $6.55 SIO - $25.50 PIO - $6.50 DMA - $18.75 All 4MHZ (who wants 2MHZ?) 74LSXX 74LS0O 74LS01 74LS02 74LS03 74LS04 74LS05 74LS06 74LS07 74LS08 74LS09 74LS10 74LS11 74LS12 74LS13 74LS14 74LS15 74LS20 74LS21 74LS22 74LS26 74LS27 74LS28 74LS30 74LS32 74LS33 74LS37 74LS38 74LS40 74LS42 74LS47 74LS48 74LS35 74LS54 74LS55 74LS73 74LS74 74LS75 74LS76 74LS78 74LS83 74LS85 74LS86 74LS90 74LS92 74LS93 74LS95 74LS96 .33 .33 .33 .33 .59 .39 .39 .39 .59 .39 .29 .39 .39 .69 1.25 .49 1.95 3.7 .29 .39 .49 .39 .49 .95 1.95 .75 .39 .25 1.39 .79 .79 .25 .25 .70 .79 .59 .79 .79 .49 .95 1.49 .95 .75 .75 .95 1.29 1.29 74LS107 74LS109 74LS112 74LS113 74LS114 74LS122 74LS123 74LS124 74LS125 74LS126 74LS132 74LS133 74LS136 74LS138 74LS139 74LS145 74LS148 74LS151 74LS154 74LS155 74LS156 74LS157 74LS158 74LS160 74LS161 74LS162 74LS163 74LS164 74LS165 74LS166 74LS168 74LS169 74LS170 74LS173 74LS174 74LS175 74LS181 74LS189 74LS190 74LS191 74LS192 74LS193 74LS194 74LS195 74LS196 74LS197 .59 .59 .59 .59 .49 .59 1.19 1.49 .89 .89 .79 1.19 .69 .99 .99 1.25 1.49 .79 2.49 1.49 1.49 1.49 1.49 .75 1.99 1.25 1.25 2.15 1.49 2.49 2.95 1.95 1.95 1.25 1.49 1.49 2.15 6.95 .99 1.95 1.95 1.95 1.49 .95 .95 1.95 74LS221 74LS240 74LS241 74LS242 74LS243 74LS244 74LS245 74LS247 74LS248 74LS249 74LS251 74LS253 74LS257 74LS258 74LS259 74LS260 74LS266 74LS273 74LS275 74LS279 74LS283 74LS289 74LS290 74LS293 74LS295 74LS298 74LS324 74LS352 74LS353 74LS365 74LS366 74LS367 74LS368 74LS373 74LS374 74LS377 74LS378 74LS379 74LS38 6 74LS390 74LS393 74LS395 74LS490 74LS668 74LS669 74LS670 2.95 2.95 2.49 1.95 1.95 2.95 8.95 1.19 1.19 1.69 1.79 .95 1.95 1.95 2.95 .75 1.15 1.75 4.39 .79 1.49 5.75 1.29 1.95 1.95 1.29 1.75 1.65 1.65 .95 .79 .99 .99 2.95 3.95 1.95 1.95 1.95 .59 1.95 1.95 1.95 4.95 1.69 1.89 3.55 394 BYTE April 1981 DEALS □ DEALS □ 0£>US OUR BUYERS ARE IN CONTACT WITH EVERY MAJOF SUPPLIER AND O.E.M. BUY HERE AT 1000 PIECE QUANTITY PRICES ALL MERCHANDISE 100% GUARANTEED! 15 DAY FULL CASH REFUND! JUST HOT STUFF POWER SUPPLIES If you can beat these prices we will be truly amazed. OEM's at 500 lot pay more than this. Call or write for full spec, sheets. DISK POWER SUPPLIES PRIAM-SHUGART-CENTURY-MICROPOLIS +5V@9A |-5V@.8A |+24V@7A | US-384 1 89.00 SHUGART- SIEMANS -MPI 514" +5V@.5A + 12V(s>.9A US-340 33.50 +5V@2A + 12V@4A US-323 56.25 SHUGART - SIEMANS - CDC 8" +5V@1A -5V@.5A +24V @ 1.5A US 205 52.50 +5V@2A -5V@.5A +24V0 3A US-206 69.00 +5V@3A -5V@.6A +24V 5A US-162 89.00 +5V@ 1.7A -5V@ 1.5A +24V @ 2A US-272 69.00 +5V@2A + 12V@.4A -12V@.4A US-HTAA 37.50 TELEVIDEO 912C SOROCIQ120- $675.00 Televideo 912C- 665.00 Televideo 920C- 720.00 ADDSR-25 - 710.00 Also have 920C, SOROC, HAZELTINE, etc. What we don't have is room on this page. Call Toll Free 800 number for prices. C-ITOH PRINTER $499.00 Look closely at the photo and see other adds in this rag at $995.00. Perfect units, warranteed. Only 500 pes. Same story, manufacturerer had too many. S-100 CARD EXTENDER $12.50 (Gold Contacts) As long as there is a price war, we will fight your battle. Compare at your local Dept. store and buy U$ MICRO. MEM0REX - VERBATUM - WABASH BASF FLOPPIES BOX OF 10 ONLY: 554" 554" 514" 8" SOFT HARD 10 HARD 16 SOFT 1D SOFT 2D SOFT2DDS $2.65 ea' 2.65 ea. 2.65 ea. 3.25 ea. 3.85 ea. 5.00 ea. Wf 664 N. MICHIGAN AVE. * SUITE 1010 * CHICAGO, ILLINOIS 6061 1 CALL TOLL FREE: 1-800-435-9357 * MONDAY thru SATURDAY (ILLINOIS RESIDENTS CALL: 815-485-4002) * 8:00a.m. to 6:30p.m. TERMS: Prepayment - C.O.D. up to $100.00 - M/C Visa $5.00 Processing and Handling added to each order PLUS Shipping Charges. Please allow personal check to clear before shipment. SPECIAL OF THE QUARTER SPECIALS OF THE MONTH S1-MOD (KIT) ^ntgTi $189.00c»jr jTjfcft Complete S-100 12 Slot Computer. Ample system power with regulated power for drives. Excellent for Subsystem or Hobby use. 4 hours to build. (6 conn, incl., less fans) DUAL DRIVE SUBSYSTEM $995.00 $195.00 w/no Drives ) I 4 If this looks like a Lobo ft Drive System, don't be fooled. Just because it 2 SHUGART 801R looks like one, works like POWER SUPPLY one, smells like one, and tastes like one (?) doesn't mean it has to cost like one! TWIN VERTICAL DRIVES 5" $550.00 - 8" $980.00 Attractive, convenient and compact Two Drive Mass Storage includes Power Supply, Drives, Cabinets and Cables. Double Sided, Double Track available too! Z-80 CPU (KIT) The first time this world popular CPU offered in Kit. 2 serial, 3 parallel, CTC, EProm Z-80 at 4 mhz. Software buad rate, etc. (less Prom & cable) $212.00 EXPANDABLE RAM *SPECIAL*SPECIAL*SPECIAL* This is the best all around 64K board you can buy. If after you see it, you don't agree return for full refund. Bank Select by extended address lines or I.O. 40H. 1|; '='as» "■■' 'SfflilP'ii* m • $389.00 A&T* U$ - D$K $255.00 Double Density 8" and 5" Disk Controller disigned for S-100 IEEE standards. Uses Western Digital 1795, 1691 2143 Chip Set. FANS $1495 9 These are brand new, in the box fans. Not noisey bearing pullouts, Never again at these low prices! 3 1/8' 4-5/8" 4116s Expansion 16K Dynamic RAMs for Apple, TRS-80 S-100 systems. T.I., Mostek Intel, Call for manufacturer. $2.95 200 NS DIP-80 $399.00 Don't be mislead by this _ LOW price. This is a rug- J| ged 100% Duty Cycle 7 by 7 Dot Matrix Printer. ^^^^^^^ — Brand new, factory warr. i • RS 232 ADD $65.00 • TRACTOR FEED ADD $70.00 2114s One of the world's two most popular STATIC RAMs. Factory prime tested units. Sold in lots of 8 only. FUJITSU, HITACHI, etc. $3.45 200 NS TMS-4044 MM-5257 INTEL 2147 $4.25 250 NS The other of the world's most popular STATIC RAMs. This one is 4K by 1 organization. Don't buy Gold, buy these, the price won't last! 2716s 2708s $9.50 (450 NS) $6.95 (450 NS) Remember when 2716s were $50.00 and hard to get? These units are so beautiful it's hard to part with them. But we will, for a small price. Guaranteed! SHUGART DRIVE 8" 801R $395.00 Manufacturer had too many, buys at 8" 851 R $585.00 1000 piece rate, sales dropped, so we got'em. Fantastic buy, get them while they last! Full warranty. SIEMANS DRIVE 8" 120-8 k , TO/w> $375.00 Very Special Price on ^ " these BRAND NEW current production units Add $10.00 for Extended 1 Year Warrantee! Circle 350 on inquiry card. BYTE April 1981 395 SALE SALE SALE Disk Drives JADE's new dual disk sub-assemblies include: Handsome metal cabinet with proportionally balanced air flow system, rugged dual drive power supply, cooling fan, cable kit, lighted power switch, approved fuse assembly, line cord, Neuer- Mar rubber feet, and all necessary hardware to mount 2-8" disk drives ■ it's all American made, guaranteed for six months, and it's in stock! Dual 8" Sub- Assembly Cabinet END-000421 Cabinet kit $225.00 END-000420 Bare cabinet $59.95 Single sided, double density disk drive sub-system END-000423 Kit w/2 8" drives .... $975.00 END-000424 A & T w/2 8" drives $1195.00 Double sided, double density disk drive sub-system END-000426 kit w/2 8" drives .... $1495.00 END-000427 A & T w/2 8" drives $1695.00 JADE DISK PACKAGE Double density controller, two 8" double density floppy disk drives, CP/ M 2.2 (configured for controller), hardware and software manuals, boot PROM, cabinet, power supply, fan. & cables Special package price $1395.00 8" Disk Drive Sale Highly reliable double density floppy dish drives Shugart 801R single sided, double density MSF-10801R SA-801R $425.00 Special Sale Price 2 for $790.00 Siemens FDD100-8D2 single sided, double density MSF-201 120 6 mo warranty $385.00 Special sale prie'e 2 for $750.00 Real Double-Sided Drives 8" Double-Sided Double-Density Sale it-******************************** * Shugart SA-851R double-sided, double-density * * only $625.00 ea 2 for $1190.00 * a******************************** MFE M701 8" double-sided, double-density drives only $525 ea 2 for $1040.00 Qume Data Track 8 double-sided, double-density drives only $575.00 2 for $1100.00 Printers CENTRONICS 737-1 i) x N dot matrix, letter quality, proportional spacing PRM- 15737 Parallel...' $795.00 With interface for Apple $895.00 MX-80 - Epson 132 column. 9 x 9 dot matrix, multiple fonts PRM-27080 Save $100.00 $545.00 Interface for Apple $1 10.00 SPINWRITER - NEC 65 cps, bi-directional, letter quality printer with deluxe tractor mechanism, both parallel and serial interfaces on- board. 16K buffer, ribbon, print thimble, graphics, micro space justification, data cable, and self test'diagnostic ROM. PRD-55511 without 16K buffer ... $2795.00 PRD-55512 with 16K buffer $2895.00 S-100 Systems S-100 SYSTEM - Calif Computer Sys Complete S-100 system including 12 slot mainframe. -I MHz Z-80 CPU. 64K RAM memory, double density dish controller, RS-2D2 cable, 8" & 5'/," disk drive cables, Cl'/M 2.2. manuals, auto boot ROM. completely assembled & tested. 2210A Integrated & tested $1995.00 2210B Not integrated $1795.00 S-100 Memory 64K RAM - Calif Computer Sys 4 MHz bank port / bank byte selectable, extended addressing. 16K bank selectable, PHANTOM line allows memory overlay, 8080 / Z-80 front panel compatible. MEM-64565A A&T $449.95 MEMORY BANK - Jade / MHz. IEEE S-100. hank selectable. ,S or 16 bit MEM-99730B Hare board $55.00 MEM-99730K Kit. no RAM $219.95 MEM-16730K 16K kit $249.95 MEM-3273 1 K S2K kit $289.95 MEM-48732K 18K kit $324.95 M EM-64733K 64K kit $359.95 Assembled & tested add $50.00 EXPANDORAM USD Systems I Mlh RAM hoard expandable from IKK to 15KK MKM-16630K 16K kit $275.95 M EM-3263 1 K H2K kit $295.95 M EM-48632K 18K kit $3 1 5.95 MKM-64633K 64K kit $335.95 Assembled & tested add $50.00 32K STATIC RAM - Jade ■> or I Mil; expandable sialic HAM hoard uses 211 il/s MEM-16I51K IKK -l Mite kit $169.95 M KM-32 1 5 1 K T2K I Mite kit $299.95 Assembled & tested add $50.00 16K STATIC RAM - Cal Comp Sys 2 or 4 MHz 16K static RAM board, IEEE S-100, bank selectable. Phantom capability, addressable in 4K blocks MEM-16160A 16K 2 MHz A&T ... $286.95 MEM-16162A 16K 4 MHz A & T . . . $289.95 MEM-16160B Bare board $50.00 PB-1 - S.S.M. 2708, 2716 EPROM board with built-in programmer MEM-99510K Kit $154.95 MEM-99510A A&T $229.95 PROM-100 - SD Systems 271)8, 2716, 27112, 2758, & 2516 EPROM programmer MEM-99520K Kit $219.95 MEM-99520A Jade A&T $269.95 S-100 Video VB-3 - S.S.M. 80 characters x 21 lines expandable to 80 X 48 for a full page of text, upper & lowercase, 25S user defined symbols, WQx 192 graphics matrix, memory mapped, has key board inpu t. IOV-1095K 4 MHz kit $375.00 IOV-1095A ■/ MHz A&T $450.00 IOV-1096K HO x 48 upgrade. $39.95 VIDEO BOARD - Jade (vt characters x Ifi lines, 7 x 9 dot matrix, full upper lower case ASCII character set. numbers, symbols, and greek letters, normal .'reverse blinking video. S-100. IOV-1050K Kit $99.95 IOV-1050A A&T $125.00 IOV-1050B Bare board $19.95 S-100 CPU 2810 Z-80* CPU - Cal Comp Sys 2, 1 MHz Z-80A* CPU with RS-2:i2C serial 1 Oport and on- board MOSS 2.2 monitor PROM, front panel compatible. CPU-30400A A&T $269.95 THE BIG Z* - Jade 2 or 4 MHz switchable Z-80" CPU with serial 1 O. accomodates 2708, 2716, or 2732 EPROM. baud rales from 75 to 9600 CPU-30201K Kit $145.00 CPU-30201A A&T $199.00 CPU-30200B Bare board $35.00 CB-2 Z-80 CPU - S.S.M. 2 or 4 MHz Z-80 CPU board with provision for up to 8K of ROM or 4K of RAM on board, extended addressing. IEEE S-100, front panel compatible. CPU-30300A A&T $229.95 SBC-200 - SD Systems •; MHz Z-80* CPU with serial & parallel 1 O ports, up to 8K of on-board PROM, software programmable baud rate generator. 1 K of on-board RAM. Z-80 CTC. CPC-30200K Kit $339.95 CPC-30200A Jade A&T $399.95 S-100 Disk Controller DOUBLE DENSITY - Cal Comp Sys B'/i" and 8" disk controller, single or double density, with on-board boot loader ROM, and free CP M 2.2* and manual set. IOD-1300A A&T $369.95 DOUBLE-D - Jade Dou ble density controller with the inside track, on-board Z- 80A*, printer port, IEEE S-100, can function on an interrupt driven buss IOD-1200K Kit $299.95 IOD-1200A 8" A&T $389.95 IOD-1205A 5>A" A & T $389.95 IOD-1200B Bare board $65.00 VERSAFLOPPY II - SD Systems Neic double density controller for both 8" & 5' " IOD-1160K Kit.'. $379.95 IOD-1160A Jade A&T $439.95 Motherboards ISO-BUS - Jade Silent, simple, and on sale - a better motherboard 6 Slot (5VS" x 8V»") MBS-061B Bare board $19.95 MBS-061K Kit $39.95 MBS-061A A&T $49.95 12 Slot (9"i" x 8%") MBS-121B Bare board $29.95 MBS-121K Kit $69.95 MBS-121A A&T $89.95 18 Slot (H'/' x 8V) MBS-181B Bare board $49.95 MBS-181K Kit $99.95 MBS-181A A&T $139.95 Card Cages S-100 CARD CAGE - Jade Metal cage with card guides & fan mounting ENX-106001 Six slot $29.95 S-100 CARD CAGE - Vector /.'/" rack mimntahlv. adjustable, hold* 21 cards VCT-CCKIOO Anodizvd A! $49.95 SALE SALE SALE S-100 I/O S.P.I.C. - Jade Our new I, () card with 2 SIO's, 4 CTC's. and 1 PIO IOI-1045K 2 CTC's, 1 SIO, 1 PIO .. $199.00 IOI-1045A A&T $259.00 IOI-1046K 4 CTC's, 2 SIO's, 1 PIO $259.00 IOI-I046A A&T $319.00 IOI-1045B Bare board w/ manual ...$59.95 IOI-1045D Manual only $20.00 1/0-4 - S.S.M. 2 serial I/O ports plus 2 parallel I/O ports IOI-1010K Kit $179.95 IOI-1010A A&T $249.95 IOI-1010B Bare board $35.00 TERMINATOR - S.S.M. Active terminator for S-100 bus TSX-195K Kit $29.95 TSX-195A A&T $54.95 TSX-195B Bare board $22.95 S-100 EXTENDER - Cal Comp Sys Put those problem boards (the ones you probably bought from one of our competitors) within easy reach. TSX-160A A&T $37.95 S-100 PROTO BOARD - Jade Universal design, plated thru holes, gold fingers TSX-140B Bare board $24.95 TERMINATOR & EXTENDER - CCS. Can he used as both an S-100 extender and terminator TSX-150K Kit $43.95 Diskettes DISKETTES - Jade Bargain prices on magnificent magnetic media 5'/i" single sided, single density, box of 10 MMD-51 10103 Soft sector $27.95 MMD-5111003 lOsector $27.95 MMD-5111603 Kisector $27.95 5'/i" douhle sided, double density, box of 10 MMD-5220103 Soft sector $39.95 8" single sided, single density, box of 10 MMD-81 10103 Soft sector $33.95 8" single sided, double density, box of 10 MMD-8120103 Soft sector $39.95 8" double sided, double density, box of 10 MMD-8220103 Soft sector $49.95 Video Monitors 9" B & W MONITOR - A.P.F. High quality, high resolution video monitor VDM-750900 9" monitor $159.95 13" COLOR MONITOR - Zenith The hi res color you've been promising yourself VDC-201301 $449.00 12" GREEN SCREEN - NEC 20 MHz. PHI phosphor video monitor with audio, exceptionally high resolution - A fantastic monitor at a very reasonable price VDM-651200 12" monitor $259.95 Mainframes MAINFRAME - Cal Comp Sys 12 slot 3-100 mainframe with 20 amp power supply ENC-l 12105 Kit $359.95 ENC-1 12106 A & T $419.95 DISK MAINFRAME - NNC Holds 2 8" drives and an 8 slot S-100 system. Attractive metal cabinet with 8 slot motherboard, power supply, fan, key switch, and other professional features ENS- 11 2320 with 30 amp p.s $699.95 Accessories-Apple/TRS-80 16K MEMORY UPGRADE Add 16K of RAM to your TRS-80. Apple, or Exidy in just minutes. We've sold thousands of these 16K RAM upgrades which include the appropriate memory chips (as specified by the manufacturer), all necessary jumper blocks, fool-proof instructions, and our 1 year guarantee. MEX-16100K TRS-80 kit $29.00 MEX-16101K Apple kit $29.00 MEX- 16102K Exidy kit $29.00 DISK DRIVE for APPLE ,5'/;" disk drive with controller for your Apple MSM-12310C with controller ...... $499.95 MSM-123101 w/out controller $375.00 DISK DRIVES for TRS-80 23% more storage, tf times faster, 40 track with free patch, 120 day warranty, includes case, power supply, and cable MSM-12410C Save $125.00 !!! ' $299.95 DOS 3.3 UPGRADE - Apple Upgrade your old DOS to the improved 3.11 IOD-2233A Complete kit $64.95 APPLE STICK - Micromate Joy stick with pots for Apple 11 SYA-1510A A&T $35.95 Z-80* CARD for APPLE Z-HO" CPU card with CP/M 2.2 for your Apple CPX-30800A A&T $279.95 AIO - S.S.M. Parallel & serial interface for your Apple IOI-2050K Kit $155.95 IOI-2050A A&T $194.95 PRINTER INTERFACE - CCS. Centronics type I/O card w/ firmware IOI-2041A A&T $99.95 APPLE CLOCK - Cal Comp Sys Real time clock w battery back-up IOK-2100A A&T $109.95 Modems •••••••••••••••••••••••■a-* LEX- 11 MODEM - Lexicon A real star.' 300 baud, answer/originate, HS 232C IOM-5511A Best buy!!! $128.00 • ••••••••••••••••-A-******* NOVATION CAT 800 baud, answer 'originate acoustic modem IOM-5200A 7 year warranty $179.00 D-CAT .100 baud, direct connect modem IOM-5201A Special sale price $189.00 AUTO-CAT Auto answer 'origiate. direct connect IOM-5230A Special sale price $239.95 MICROMODEM - D.C. Hayes Auto answer dial modem card for Apple or S-100 IOM-2010A Apple modem $349.95 IOM-1100A S-100 modem $375.00 MICRONET MODEM - Micromate Direct connect with extra features - a best buy IOM-2020A Best Apple modem .... $275.00 • Z-80, Z-80A, and the letter Z are recognized trademarks of Zilnf*. Inf. *CP/M is a registered trademark of Digital Research Corp. *CBASIC is a trademark of Compiler Systems, Inc. Circle 351 on Inquiry card. Single Board Computers AIM-65 - Rockwell 6502 computer with alphanumeric display, printer, & keyboard, and complete instructional manuals CPK-50165 IK AIM $374.95 CPK-50465 4K AIM $449.95 SFK-74600008E 8K BASIC ROM ...$99.95 SFK-64600004E 4K assembler ROM $84.95 PSX-030A Power supply $64.95 ENX-000002 Enclosure $49.95 4K AIM, 8K BASIC, power supply, & enclosure Special package price $625.00 Z-80* STARTER KIT - SD Systems Complete Z-80" computer with RAM. ROM. I/O. display, keyboard, manual, and kluge area. CPS-30010K Kit $369.95 CPS-30010A Jade A&T $459.95 MICROPROCESSORS Z-80 10.95 Z-80A 12.95 8502 11.50 6800 11.95 B802 17.95 (5809 39.95 8035 24.00 8080A 6.59 8085 15.95 8748 59.95 Z-80 SUPPORT 3881 PIO 9.50 3881-4 PKUMHz 14.50 3882 CTC 9.50 3882-4 CTC-I MHz 14.95 3883 SIO 29.50 3884 SIO 49.50 BAUD RATK GENERATORS MC14411 10.00 1.843 MHz xtal 4.95 UARTS AY5-10I3A 5.25 AY3-1014A 8.25 TR1602B 5.25 TMS6011 5.95 IM6402 9.00 6800 SUPTORT 6821P 5.95 6828P 11.95 6H34P 22.50 6840P 18.75 6850P 4.80 6852P 5.79 68751. 7.40 084H8P 25.00 PROMS 2708 -toOns 6.25 10 for $4.90 ea 2716 12f,v 11.95 2716 ,5i> 11.95 10 for $8.90 ea 2532 .5i> 39.95 2T.ti St) 39.95 2758 So 9.95 RAMS 21UK2 2 MHz 1.25 21U12A / MHz 1.50 2I14L 2 MHz 3.75 2114LA -I MHz 3.95 4116 4.25 4164 MK.xl 59.95 5257 2 MHz 675 5257A / MHz 7.25 MK4118 IR95 SUPPORT DEVICES 8212 8214 8216 8224 8224-: 8226 8228 8238 824.3 8250 8251 8253 8255 8257 8259 8275 8279 3.25 4.65 2.95 3.25 . 5.75 3.85 4.95 4.95 ,. aoo 14.95 6.50 17.95 6.50 19.95 17.95 49.95 15.95 PLACE ORDERS TOLL FREE Continental U.S. Inside California 800-421-5500 800-262-1710 For Technical Inquiries or Customer Service call 213-973-7707 Computer Products 4901 W. Rosecrans, Hawthorne, Ca 90250 TERMS OF SALE: Cash, checks, credit cards, or Purchase Orders from qualified firms and institutions. Minimum order $15.00. California residents add S% tax. Minimum shipping and handling charge $H.0fl Pricing and availability subject to change without notice. SN74O0N SN7401N SN7402N SN7403N SN7WN SN7405N SN74Q6N SN7407N SN7408N SN74Q9N SN7410N SN7411N SN7412N SN7413N SN7414N SN7416N SN7417N SN7420N SN7421N SN7422N 5N7423N SN742SN SN7426N SN7427N SN7428N SN7430N SN7432N SN7437N SN7438N SN7439N SN7440N SN7441N SN7442N SN7443N SN7444N SN7445N SN7446N SN7447N SN7448N SN7450N SN74S1N SN7453N SN7454N SN7459A 5N7460N SN7470N 74LS0O 74LS01 74LS02 74LSQ3 74LS04 74LSOS 74LS08 74LS09 74LS10 74LS11 74LS12 74LS13 74LS14 74LS15 74LS20 74LS21 74LS22 74LS26 74LS27 74LS28 74LS30 74LS32 74L533 74LS37 74LS33 74LS40 74LS42 74LS47 74LS48 74LS49 74LS51 74LS54 74L555 74LS73 74LS74 74LS75 74LS76 74L578 74LS83 74LS85 74 L 586 74LS90 74S00 74S02 74S03 74S04 74S05 74508 74S09 74S10 74S1I 74S15 74S20 74S22 74S30 74S32 74S40 '4551 74S64 74565 74S74 74S86 74S112 745113 74 SI 14 * LIM 7400 SN7472N SN7473N SN7474N SN7475N SN7476N SN7479N SN7480N SN7482N SN7483N SN7485N SN74B6N SN7489N SN7490N SN7491N SN7492N SN7493N SN7494N SN749SN SN7496N SN7497N 5N74100N 5N74107N SN74109N SN74116N SN74121N SN74122N SN74123N SN74125N 5N74126N SN74132N SN74136N SN74141N SN74142N SN74143N SN74144N SN74I45N SN74147N 5N7414BN SN74150N SN74151N SN74152N SN74153N 5N74154N 5N741S5N 3.2S 3.49 3.49 74LS 74LS92 74LS93 74LS95 74LS96 74LS107 74LS109 74 LSI 12 74LS113 74LS114 74LS122 74LS123 74L5125 74LS126 74LS132 74LS133 74LS136 74LS138 74LS139 74LS151 74LS153 74L5154 74LS155 74LS156 74LS157 74LS158 74LS160 74LS161 74LS162 74LS163 74LS164 74LS165 74LS16B 74LS169 74LS170 74L5173 74LS174 74LS175 74LS181 74LS190 74LS191 74S 74S133 74S134 74S135 74S136 74S13S 74 S 139 74 S 140 745151 74S153 745157 745158 74S174 745175 74S188 74S194 74S195 745196 745240 745241 74S242 74S243 'TED AVAILABILITY 74LS192 74LS193 74LS194 74LS195 74LS197 74LS221 74LS240 74LS241 74LS242 74LS243 74LS244 74LS245 74LS247 74LS248 74LS249 74LS2S1 74LS253 74 L 5257 74LS258 74LS260 74LS2S6 74LS273 74LS279 74LS283 74 L 5290 74L5293 74LS29B 74LS352 74LS3S3 74LS36S 74LS366 74LS3G7 74LS368 74LS373 74LS374 74LS375 74LS386 74LS393 74LS399 74LS67Q 81LS95 81LS97 74S244 745251 74S253 74S257 74S258 745260 745280 74S287* 74S288* 745373 745374 745387* 74S471* 74S472* 745473* 74S474* 745475* 74SS70* 74SS71* 745572* 74S573* 74S940 745941 ESE PR 1.15 1.15 1.15 1.95 1.95 1.95 2.49 2.49 2.49 5.95 19.95 19.95 19.95 21.95 21.95 7.95 7.95 19.95 19.95 3.15 CA3013H CA3023H CA3039H CA3046N CA3059N CA3060N CA3080H CA-LINEAR CA3081N CA3082N CA3Q83N CA3086N 2.00 2.00 1.60 CA3089N CA3096N CA3I30H CA3140H CA3160H CA3401N CA3600N CD4000 CO4001 CD4002 CD40O6 CD4007 CD4009 CD4010 CD4011 CD4012 CO4013 CD4014 CD4015 CD4016 CD4017 CD4018 CD4019 CD4020 C D402I CD4022 CD4023 CD4024 CD4025 CD4026 CD4027 CD4028 CO4029 CD4030 CD4035 CD4040 CD-CMOS CD4041 CD4042 CO4043 CD4044 CD4046 CD4047 CD4048 CD4049 CD4050 CD4051 CD4052 CD4053 CD4056 CD4059 CD4060 CD4066 CO4068 CD4069 CD4070 CD4071 CD4072 CD4073 CD4075 CD4076 CD4078 CD4081 CD4082 CD4093 CD4098 CD4506 CD4507 CD4508 CD4510 CD4S11 CD4514 CD4515 CD4516 CD4518 CD4519 C D4S20 CD4526 CD4528 CD4529 CD4543 CD4562 CD4566 CD4S83 CD4723 C D4724 MC 14409 MC14410 MC14411 MC14412 MC 14419 M C 14433 1.79 1.79 1.95 2.79 11.95 2.79 1,95 14.95 14.95 14.95 11.95 4.9S 13.95 LITRONIX DISPLAY SALE MULTI-DIGIT R DL-4500 DL-4507 DL-4520A DL-4120A LECTOR <".r — «c»™, •*«" 1=="' 1ST ..«. TV- M,N **A IV, | MAX SuSSmSi „ c. m. i o.|.t ^ tmn * u ,. "\" , 2.49 Z.4B d^bmI S&! «-», ' s 4,95 4.B5 S.4B OL41MA,..., 10 "■""' '* ' „ | .. 4.05 MULTI-DIGIT RE LECTOIl ARRAYS OLJ3MIII.ni .30 CCMP. ?s»« iptmap.mgni IS II !0 17 ID 30 .00 DUMIM tfMnl ;:■ C 1 VI'. B S., ! D.,.1 u X !■, n 1 1.4B nuKJi".;. to cc •»• BS^tD.) ::■■ B r : 1 J M W !0 30 Z.49 OL.aSOOtH..!) .60 C C. Uf X JUa goig UP ,*-.-. B 6 10 U !0 30 | 2. 99 QL4U0 [11. 01 60 1- '. Ml'. <5. S UU.OHDP It, it.. 11 1 10 1.7 10 30 | 2.B9 dl ma mm >< CA m J In 3 D. ( »' *v< It 10 >o J* «0 30 3. as DISCRETE LEDS XC556R .200" red XC5S6G .200" green XC556Y .200" yellow XC556C .200" clear XC22R .200" red XC22G .200" green XC22Y ,200" yellow MV10B .170" red S/Jl 4/J1 4/S1 4/S1 S/Sl 4/$l 4/$l 4/J1 MV50 .085" red XC209R .125" red XC209G .125" green XC209Y .125" yellow XC526R .185" red XC526G .185" green XC526Y .185" yellow XC526C .185" clear 6/$l 5/$l 4/11 4/S1 5/$l 4/(1 4/$l 4/$l XC111R .190" red 5/(1 XC111G .190" green 4/S1 XC111Y ,190" yellow 4/$l XC111C .190" clear 4/$l ^^Tc' BM RED LEO METAL RL-2 . .$.39ea.or3/$1.00 CA. - Common Anode DISPLAY LEDS CC ' - Common Cathode Typa MAN 1 MAN 2 MAN 3 MAN 52 MAN 54 MAN 71 MAN 72 MAN 74 MAN 82 MAN 84 MAN 3620 MAN 3630 MAN 3540 MAN 4610 MAN 6610 MAN 6630 MAN 6640 MAN 6650 MAN 6660 MAN 6710 MAN 6750 MAN 6780 DLO304 DLO307 DLG500 Polarity C.A.— red 5x7 D.M.— red CC— red C. A. —green C.C. — green C.A.— red C.A.— red C.C— red C. A.— yellow C.C— yellow CA.— orange CA.— orange ± 1 C.C— orange C. A. —orange C.A.— orange— DD . C.A.— orange z 1 C.C— orange— OD . C.C— orange ± 1 C. A.— orange C.A.— red— DD C.C— red ± 1 CC— red C.C— orange CA.— orange C.C— green Type DLG507 DL704 DL707 DL728 DL741 OL746 DL747 DL750 DL0847 OLO850 DL33B FND358 FND359 FND503 FND507 HDSP-3401 H DSP -3403 5032-7751 5082-7760 5082-7300 5082-7302 5082-7304 4N2B LIT-1 MOC3010 Ht .500 .300 Polarity C. A. —green C.C— red CA.— red C.C— red C.A.— red C.A.— red ± 1 C.A.— red C.C— red CA.— orange C.C— orange C.C— red C.C. ± 1 C.C. C.C. (FNDSOO) CA. (FND510) C.A.— red C.C— red C.A.,R.H.D.— red .430 C.C.R.H.D.— red .430 4x7 591. dig. RHD .600 4x7sgl.dlg. LHD .600 Ouernge. char. (±1) .600 Photo XslstorOpto-lsa Photo Xslstor Opto-lsc Optically Isol.TrlacDrl' .800 22.00 22.00 19.95 POTENTIOMETERS ^ $2.95 each 2 Watt SO 7 0°C ± 10% 7/8" Slotted Shaft Linear Tepar Meets Mil-R-94 RV4NAY SD- 102A RV4NAY SD - 502A RV4NAY SD - 103A RV4NAY SD - 2S3A RV4NAY 5D - 503A RV4NAY SD - 104A RV4NAY 5D • 105A IK 5K 10K 25 K 50 K 100K lMeg LOW PROFILE (TIN) SOCKETS 8 pin LP 14 pin LP 16 pin LP 18 Pin LP 20 pin LP 22 pin LP 24 pin LP 28 pin LP 36 pin LP 40 pin LP SOLDERTAIL (GOLD) STANDARD 24 pin SG 28 pin SG 36 Pin SG 40 pin SG $1.35 each Part No. 830P- 50ohrr B30P-100ohrr 830P-600ohrr B30P-1K 830P-2K 830P- 5K 830P-10K 830P-20K 630P-50K 830P-100K 830P-200K 830P-500K B3aP-lMeg SOLDERTAIL STANDARD (TIN) 14 pin ST 16 pin ST 18 pin ST 24 pin ST 28 pin ST 36 pin ST 40 pin ST WIRE WRAP SOCKETS (GOLD) LEVEL #3 8 Pin WW 10 pin WW 14 pin WW 16 pin WW 18 pin WW 20 pin WW 22 pin WW 24 pin WW 28 pin WW 36 pin WW 40 pin WW 1.23 1.14 1.38 1/4 WATT RESISTOR ASSORTMENTS -5% ASST T 5ea. 10 Ohn 27 Ohn i 12 Ohm i 33 Ohm 15 Ohrr 39 Ohrr 18 Ohm 47 Ohm 22 Ohm 56 Ohm 50 pes. $1.95 ASST 2 5ea. 68 Ohn 180 Ohn i 82 Ohm 220 Ohm 100 Ohnr 270 Ohrr 120 Ohm 330 Ohm 150 Ohm 390 Ohm 50 pes. $1.95 ASST 3 5 en. 470 Ohn 1.2K 560 Ohm l.SK 680 Ohrr 1.8K 820 Ohm 2.2K IK 2.7K 50 pes. $1.95 ASST 4 5ea. 3.3K 8.2K 3.9 K 10K 4.7K 12K 5.6K 15K 6.BK 1SK 50 pes. $1.95 ASST 5 5ea. 22 K 56K 27K 68K 33 K B2K 39K 100K 47K 120K 50 pes. $1.95 ASST 6 5aa. 1S0K 390 K 180 K 470 K 220K 560 K 270 K 680 K 330 K 820K 50 pes. $1.95 ASST 7 5fl3. 1M 2.7M 1.2M 3.3M 1.5M 3.9M 1.8M 4.7M 2.2M 5.6M 50pcs. $1.95 ASST. 8R Includes Resistor Assts. 1-7 (350 pes.) $10.95 ea. S10.00 Min. Order - U.S. Funds Only Calif. Residents Add 6% Sales Tax Postage — Add 5% plus51 Insurance rcAT&ss* J a EEHH33H11 Spec Sheets - 25rf Send 41rf Postege for your FREE 19B1 JAMECO CATALOG PHONE ORDERS WELCOME (415) 592-8097 MAIL ORDER ELECTRONICS - WORLDWIDE 1355 SHOREWAY ROAD, BELMONT, CA 94002 PRICES SUBJECT TO CHANGE -\ Part No. Function Price 7045IPI CMOS Precision Timor 14.95 7045EV/KH* Stopwatch Chip, XTL 22.95 7106CPL 3ft Digit A/D (LCD Drive) 16.95 7106EV/KU* IC. Circuit Board, Display 34.95 7107CPL 3V; Digit A/D (LED Drive) 15.95 7107EV/KU* IC, Circuit Board, Display 28.95 7116CPL 3>fc Digit A/D LCD DIs. HLD. 18.95 7117CPL 2Vi Digit A/D LED DIs. HLD. 17.95 7201IDR Low Battery Volt Indicator 2.2S 7205IPG CMOS LED Stopwatch/Timer 12.95 7205EV/Klt* Stopwatch Chip, XTL 19.95 7206CJPE Tone Generator 5.1S 7206CEV/KU* Tone Generator Chip, XTL 9.95 7207AIPD Oscillator Controller 6.50 7207AEV/KU* Preq. Counter Chip, XTL 11.10 7208IPI Seven Decade Counter 17.95 7209IPA Clock Generator 3.95 7215IPG 4 Func. CMOS Stopwatch CKT 13.95 7215EV/KU* 4 Func. Stopwatch Chip, XTL 19.95 7216AIJI 8-Diglt Univ. Counter CA. 32.00 7216CIJI 8-Dlglt Freq. Counter C. A. 26.95 7216DIPI B-Dlglt Freq. Counter C.C. 21.95 7217IJI 4-Diglt LED Up/Down Counter 12.95 7218CIJI 8-Diglt Univ. LED Drive 10.95 7224IPL LCD4Va Digit Up Counter DRI 11.25 7226AIJL 8-Dlglt Univ. Counter 31.95 7226AEV/KU" 5 Function Counter Chip, XTL 74.95 7240IJE CMOS Bin Prog. Timer/Counter 4.95 7242IJA CMOS Dlv|de-by-256 RC Timer 2.05 7250IJE CMOS BCD Prog. Timer/Counter 6.00 7260IJE CMOS BCD Prog. Timer/Counter 5.25 7555IPA CMOS 555 Timer (B pin) 1.45 7556IPD CMOS 556 Timer (14 pin) 2.20 761IBCPA CMOS Op Amp Comparator 5MV 2.25 7612BCPA CMOS Op Amp Ext. Cmvr. SMV 2.95 7621BCPA CMOS Dual Op Amp Comp. 5MV 3.95 7631CCPE CMOS Trl Op Amp Comp. 10MV 5.35 7641CCPD CMOS Quad Op Amp Comp. 10MV 7.50 7642CCPD CMOS Quad Op Amp Comp. 10MV 7.50 7660CPA Voltage Converter 2.95 B069CCQ 50ppm Band— GAP Volt Ret. Diode 2.50 8211CPA Volt Ref/lndlcator 2.50 8212CPA Volt Ref/lndlcator 2.50 * INTERSIL'S EVALUATION KITS 74C00 74C02 74C04 74 COB 74 C10 74C14 74C20 74C30 74C42 74C48 74C73 74C74 74C6S 74C86 74C89 74C90 74C93 74C95 1.59 74C 74C195 74C221 74C240 74 C 106 .75 74C244 74C107 1.89 74C373 74C151 2.95 74C374 74C154 3.95 74C901 74C157 2.25 74C903 74 C 160 1.69 74C911 74 C 161 1.60 74C912 74 C 162 1.49 74C915 74C163 1.69 74C917 74C164 1.59 74C922 74 C 173 1.39 74C923 74 C 174 1.39 74C925 74C175 1.39 74C926 74C192 1.69 80C95 74 C 193 1.69 80C97 1.59 1.95 2.25 2.25 2.49 2.59 10.95 5.49 5.75 .79 LH0002CN 6.85 LM10CLH 4.50 LM11CLH 4.75 LH0070-OH 6.05 TL071CP .79 TL072CP 1.39 TL074CN 2.49 LH0082CD 35.80 TL082CP 1.19 TL0B4CN 2.19 LH0094CD 36.80 LM300H .99 LM301CN .35 LM302H LM304H LM305H LM307CN LM308CN LM309H LM309K LM310CN LM311H LM312H LM317MP LM317T LM317K LM31BCN LM319N LM320K-5 LM320K-12 1.35 LM320K-15 1.35 LM320T-5 1.25 LM320T-12 LM320T-15 LM323K-5 LM324N LM329DZ LM331N LM334Z LM33SZ LM336Z LM337T LM337MP LM338K LM339N .99 LM340K-5 1.35 LM340K-12 1.35 LM340K-15 1.35 1.95 1.00 1.15 1.75 3.95 1.95 5.95 3.95 6.95 LINEAR LM340T-5 1.25 LM340T-12 1.25 LM340T-15 1.25 LM341P-5 .75 LM341P-12 .75 LM341P-I5 .75 LM342P-5 .69 LM342P-12 .69 LM342P-15 .69 LM348N LM350K LF351N LF353N LF355N LF356N LM358N LM359N LM370N LM373N LM377N LM380N LM381N LM382N LM3B4N LM3S6N-3 LM3B7N LM389N LM392N LF398N LM399H TL494CN TL496CP NE510A NE529A NE531H NE536H NE540H NE544N NE550A NE555V LM556N NE564N LM565N LM566CN LM567V S.7S 4.00 6,00 4.95 3.95 6.00 6.00 4.95 29 2.75 NE570N LM702H LM703CN LM709N LM710N LM7UN LM723N .69 LM733N 1.00 LM739N 1.19 LM741CN .35 MC1741SCG 3.00 LM747N .79 LM748IN .59 LM1014N LM1310N LM1458CN LM1488N LM1489N LM1496N LM 1556 V LM1800N LM1877N-9 LM18B9N LM1B96N LM2002T LM2877P LM2B78P LM2896P-1 LM3189N LM3900N LM3905CN LM3909N LM3914N LM3915N LM3916N RC4136N RC4151NB RC4194TK RC4195TK KB4428 KB4429 LM45O0A ICL8038B LM13080N LM13600N 75138N 75450 N 75451 CN 4.95 CAPACITOR CORNER 50 VOLT CERAMIC DISC CAPACITORS Value 1-9 10-99 100+ Value 1-9 10-99 100+ 10 pf .08 .06 .05 .OOluF .08 .06 .05 22 pf .08 .06 .05 .0047uF .08 .06 .05 47 pf .08 .06 .05 .Oliii .08 .06 .05 100 pf .08 .06 .05 .022mF .09 .07 .06 220 pf -08 .06 .05 -047uF .09 .07 .06 470 pf .OB ,06 .05 .UiF .15 .12 .10 100 VOLT MYLAR FILM CAPACITORS .OOlmt .12 .10 .07 I .022m f .13 .11 .08 ,0O22mf .12 .10 .07 .047mf .21 .17 .13 .0O47mf .12 .10 .07 .lmf .27 .23 .17 .Olrnf .12 .10 .07 I .22mf .33 .27 .22 +20% DIPPED TANTALUMS (Solid) CAPACITORS -1/35V . 15/35 V -22/35V . 33/35 V . 47/35 V .68/35 V 1.0/35V .39 .34 .39 .34 .37 .29 .41 .51 .53 .47 .37 .63 .56 .45 .79 .69 .55 1.39 1.25 .95 .79 .69 .55 MINI. ALUMINUM ELECTROLYTIC CAPACITORS 1.5/35V 2.2/3SV 3.3/25V 4. 7/25 V 6.8/25V 15/25V 22/6V -47/50V 1.0/50V 3.3/50V 4.7/2SV 10/25V 10/50V 22/25V 22/50V 4 7/25 V 47/50V 100/2SV 100/50V 220/25V 22O/50V 470/25V 1000/1SV 220O/16V Axial Lead .19 .16 .12 .17 .15 .11 .79 .69 .61 .47/2SV .47/50V 1.0/16V 1.0/25 V 1.0/S0V 4. 7/16 V 4.7/25V 4.7/50V 10/16V 10/25 V 10/50V 47/SOV 100/ 16 V 100/25 V 100/SOV 220/16V 4 70/25 V Radial Lead .16 .14 .13 .25 .21 .19 398 BYTE April 1981 sSSduoter Clock Modules 12VDC AUTOMOTIVE/ INSTRUMENT CLOCK APPLICATIONS: • In-dash autoclocks • A*tor-rnarket auto/ RV clocks • Aircraft-marine elks. • 12VDC oper. Instru. • Portable/battery powered instrumnts. Features: Bright 0.3" green display. Internal crystal time- base. i0.5 sec/day accur. Auto. display brightness control logic. Display color filterable to blue, blue-green, green & yellow. Complete— just add switches and lens. MA1003 Module $16.95 MAI 023 .7" Low Cost Digital LED Clock Moduli 8.95 MA1026 .7" Dig. LED Alarm Clock/Thermometer 18.95 MAS036 .3" Low Colt Digital LED Clock/Timer 6.95 MA1002 .5" LED Display Dig. Clock & Xlormer 9.95 2 National Semiconductor RAM SALE MM5290N-4 (MK4116/UPD416) . . $4.95 each 16K DYNAMIC RAM (250NS) (8 EACH $39.95) (100 EACH $450.00/lot) MM5290J-2 (MK4116/UPD416) . . $6.95 each 16K DYNAMIC RAM (150NS) (8 EACH $49.95) (100 EACH S550.00/lotl MM5298J-3A $3.25 each 8K DYNAMIC RAM [LOW HALF OF MM5290J) 200NS (8 EACH $23.95) (100 EACH $250,00/Jot) MM21 14-3 $5.95 each 4K STATIC RAM (300NS) (8 EACH $43.95) (100 EACH S450.00/lot) MM21 14L-3 $6.25 each 4K STATIC RAM (LOW POWER 300NS) (8 EACH $44.95) (100 EACH S475.00/lot) EPROM Erasing Lamp • Erases 2708. 2716, 1702A, 5203Q, 5204Q, ate. • Erases up to 4 chips within 20 minutes. • Maintains constant exposure distance of ona inch. • Special conductive foam liner eliminates static build-up. • Built-in safety lock to prevent UV exposure. • Compact - only 7-5/8" x 2-7/8" X 2" ■ Complete with holding tray for 4 chips. UVS-11E.. ........ ..$79.95 Jumbo 6-Digit Clock Kit • Four ,630"ht. end two .300"ht. common anode displays • Uses MM5314 clock chip • Switches for hours, minutes and hold functions • Hours easily viewable to 30 feet • Simulated walnut case • 1 1 5VAC operation • 12 or 24 hour operation • Includes all components, case and wall transformer • Size: 6M"x 3-1/8" X 1K" JE747 $29.95 6-Digit Clock Kit • Bright .300 ht. comm. ca' ode display • Uses MM5314 clock chip . for hours, linutes and hold modes • Hrs. easily viewable to 20 ft. ■ Simulated walnut case • 115 VAC operation • 12 or 24 hr. operation • Incl. all components, case & wall transformer • Size: &V<" x 3-1/8" x 1M" JE701 $19.95 m^ JE215 Adjustable ISpr Dual Power Supply General Description: The JE215 is a Dual Power Supply with independent adjustable positive and nega- tive output voltages. A separate adjustment for each of the supplies providesthe user unlimited applications for IC current voltage requirements. The supply can also be used as a general all-purpose variable power supply. FEATURES: ■ Adjustable regulated power supplies, pos. and nog. 1.2VDC lo 15VDC. • Power Output (each supply): SVDC !s> 500mA, 10V DC @ 750mA, 12VDC@ 500mA. and 15VDC@ 175mA. • Two, 3-terminal adj. IC regulators with thermal overload protection. • Heat sink regulator cooling • LEO "on" indicator • Printed Board Construction • 120VAC input • Size: 3-1/2"w x 5-l/16"L x 2"H JE215Adj. Dual PowerSupply Kit (asshown) . . $24.95 (Picture not shown but similar in construction to above) JE200 Reg. Power Supply Kit (5VDC, lamp) .. $14.95 JE205 Adapter Brd. (to JE200) ±5,-9 & -12V. $12.95 lwJE210Var.Pwr. Sply.Kit, 5-15VDC,to1.5amp. $19.95 MICROPROCESSOR COMPONENTS INSBOWA DP1212 DPBU 8080A/8080A SUPPORT DEVICES - CPU S-BU Insut/Outdut Priority Interrupt Conirol Bl-Diii OPSHS I NS1M3 INSB250 DPS2S1 DP8253 OP8255 OPS257 DPJ259 opaan Dmn DPB30O DPB303 DPS 304 OPB307 DP830S But DrUsr Syit«m Contrc ar/Orli . I/O IUSART) ■ral i/o (ppi) lontiot Dl Control ira/Diiol»y intomce Sytum Timing Elemsnt 8-Blt BI-Olrectlon»l Recalv S-BIt Bl-Oliectlonil Racelv B-BIt BI'Dlcecllonil Raeelv 6800/6800 SUPPORT DEVICES - MC6800 MPU MCSM'CP MPU wlln ClocK *n0 HAM MC6BIQAPL l?8xl Slilic RAM IMccnS] MCU21 MCS828 MCSUOU MC68S0 MCM52 MC«60 MC6KZ MC6M0A zta (tsoc) Z&OA (ISO-l) cdpibot. aso IOM2901AOC MC56502 NSB03SN-* NSBOMN-6 NSBWON-6 NS8070N P808S NSSWO rMSWOOJL 0*MD0i Oigltil MODEM 2400opt r/odulitoi Quad 3-Slite But. Tr»nj. (MCSTM) MICROPROCESSOR CHIPS — MPU : CPU-«-B /o.»D K62 62-Key Keyboard (Keyboard only) . . .$ 34.95 DTE-AK (case only -3Vi"Hxll"Wx8V«"D)$ 49.95 JE600 Hexadecimal Encoder Kit FULL 8-BIT lflL^A \ LATCHED OUTPUT ^ft VHfc \ 19-KEY KEYBOARD ^ -- \ The JE600 Encoder Keyboard Kit provides two separate hexadecimal digits produced from sequential key entries to allow direct programming for 8-bit microprocessor or 8-bit memory circuits. Three additional keys are pro- vided for user operations with one having a bistable output available. The outputs are latched and monitored with 9 LED reedouts. Also included Is a key entry strobe. Features: Full 8-bit latched output for microprocessor use. Three user-define keys with one being bistable operation. Debounce circuit provided for all 19 keys. 9 LED readouts to verify entries. Easy Interfacing with standard 16-pln IC connector. Only +5VDC required for operation. Size: 3'/."H x 8'ri"W x 8«"D JE600/DTE-HK (as pictured above) .... $99.95 .renn ■/■■* 19-Key Hexadec. Keyboard, acq qc JbbUU Kit PC Board tCmpnts. (no case) . .*oy.yo K19 19-Key Keyboard (Keyboard only) .... $14.95 DTE-HK (case only —3Vi"HxaV4-WxaV4"D) $44.95 Circle 352 on inquiry card. BYTE April 1981 399 CAlifORNIA DiqiTA Post Office Box 3097 B • Torrance, California 90503 FREE PLASTIC LIBRARY CASE INCLUDED WITH THE PURCHASE OF EVERY BOX OF DISKETTES ■ivale labeled for California Digital by one of c most respected producers of magnetic media, i ich diskette is certified double density at 40 acks. To insure extended media life each dls- I kette is manufactured with a reinforced liub-Jiole. I And of couthc, a plastic library case Is included | with every box of diskettes. MMO-CDS(OIHIO) ise specify computer or required sectors. ■I I. BOX Ten boxes $22.75 MINIDISKETTES One hundred boxes $21.50 10 boxes S2y.oo EIGHT LNCH Scotch „vv 10 bx Dysan box 10 " MUX box Ohl Single ■skWMllgte dm. 740-0 MM. $33. 3740/1 MO. $ IV. 3060 Single side/ double dm 741-0 4h. 3740/1 ( 75. /H. 3090 87, 35. .Single side/32 sec 740-33 Hfi. 33. nouble side/ doubt D U. 743-0 Kb. 59. na. 3115 49. 45. SCOTCH brand he ad c eaning kit. $24.35 MMA-CK{ KB) pi as specify 81/ B" Prices available o n request for tap ridges, dl kpadta volumn dl akeltcs. NEW from Shugart Technology s Megabyte Hard Disk Drive Packaged in the same physical size as the industry stan- dard 5 1/4" minifloppy disk drive. The micro- Winches- ter stores thirty times as much data (6.38 megabytes unformatted), accesses data twice as fast {170 milli- seconds) and transfers data twenty times faster (5.0 megabits per second. ) The ST506 is factory sealed to protect the media from environmental contaminates. Requires only DC voltage. enclosure, felCAA SURPLUS Dual California Digital 5 1/4" ST506 drive and power supply. Shugart Associates SA400 removable media disk drive for above package, add: S-100 & Apple controller scheduled for spring release. rvi TRS-80 • APPLE II 16k memory (8)4116 's Installation is simple. Anyone who has ever changed a spark plug should be able <. to up-grade his microcomputer. How can California Digital offer these memory up-grade sets at 25% below our competition? Simple, we buy in volume, wholesale to dealers and sell the balance directly to owners of personal micro- systems. These 16K dynamic memory circuits are factory prime and unconditionally guaranteed for one full year. NOW, before you change your mind, pick up the telephone and order your up-grade memory from California Digital. Add $3 for TRS80 jumpers. STATIC 21L02 450nS. 21L02 250nS. 2114 1KX4 450 2114 1Kx4 300 4044 4Kxl 450 4044 4Kxl 250 4045 1Kx4 450 4045 1Kx4 250 5257 low pow. 1-31 1.19 1.49 5.95 8.95 5.95 9.95 8.95 9. 95 5.95 32-99 100-5C -999 1K+ 1.39 5.50 8.50 5.50 9, 50 8. 50 9.50 5.50 5. 25 8. 00 5. 25 9.00 8. 00 9.00 5. 00 4.80 4.60 2716 EPROM We have slashed price in an effort to reduce our over stocked inventory. These are single five volt EPROMs ] manufactured by one of the Worlds largest producers of semiconductors. All are first, quality prime devices. Ceramic 450 nS. I UlTR/vVioUT ProcIucts LVS HE UV EPROM ERASER With purchase of FORTY 2716 EPROM's */V value *300 2 ;piit 2 Split ^' S-IOO ■*-, J > 9VDC |p- 22V, ct jT~ 24V disk Cl5V. f 15V. £ Fan POWER SUPPLY KIT $ 59 801/ R Disk Drive 15 lbs Shugart 801/R with CP306 power mipply, muffin c. plcte in dual enclosure with .ill the necessary ham Documentation included. 3fi pounds, MSIJ- 1B01 Same as .ibove but Willi two Shujjart 801 H disk drives. SO pounds. MSD-2H0! Disk dtiV« cahle. 6 fee! .i0 conductor with edge card connec at both ends. WCA-S50S $25,00 , 220V. 50MHsi add $50.00 per dink driv The new jpplianct iating Sy HSR timer runs yo 8 while your away tem X-10 device's 2& S£ llku cloc Couplet ely rk Tu E onl with amps and USB Tim Muster c Ultras on er eight channel c Controller $65.00 34.05 Appliance Module 500 W Lamp Moduli 300 Watte NEW full control wall sv. $13.05 13. f)5 ich 14.50 Rotron Wisper Fan $ 14 77 115 VAC. 7 Watts WR2A1 Factory fresh Muffin fans NOT pull-outs. EMF-4M S-100 .125' Imsni soldi tmaai wire wrap (I'D Sullins Hi-Rel. .250' Sullins Hi-Rel. WAV Sullins/AJlatr - HO" ,156" Ccr ird) 22/44 Kim Evolot 2.50 2. 36/72 Digital Group S/T 5.05 5. 36/72 Digital Crimp WAV 6. fit) C. 43/86 Motorola 0800 S/T 6.BD 6. 43/86 Moto. 6B0O WW 7.00 6. BCTBGRATED CIRCUIT SOCKETS IJB hood 2IP 1.38 DC371' male 4.20 PC37S female ti.00 B.OO H.00 RIBBON CABLE CONNECTORS 17/34 5" disk 4.85 4.15 3.05 20/40 TltS-80 5.65 5.05 4.70 23/50 8" disk 5.90 5.15 4.U0 It contains fi vi- hii;h eiii-rmt lirii! ( :i- rectifier* livi- i:oiii|puii-r cradc electro- nic capacitors and a 700 ' w.itt split primary transformer (1 1(1/ 220V.) he supplv is capable of supporting 9 full 30 Amp S-100 svstein along with 12) lectrolytic capacitors consist of: one each HJ.000 ul / l.iV; IH.OOU til- MUV; 6,CI00uW.H)V; Hid TWO 1 2.0007 30V. ,11 components lire new surplus acquired from aXCOSS Inventory of the luiional Cub Register Company, li'.ise place vmir Order e.irlv, at thin low price *tt expect this kit i" !••■ . nick sell out. SPC-PW10O. . ..Shipping: east Of Mississippi add SI 5.00 □ATA INPUT TERMINAL This Keyst quired froi Corporation. I ' a dire tlyo iriglnally designee The svsten; in comprised of ,i prer-.tui-.. c;ist aj-.m.im-.i:ti .uid fiber,']. .ss enclosure. .tlong'with a Honeywell .' Microswitch hall effect keyboard. Thirty diapt-iy lamps iidvise tile operator of tin: systems tit.itus. Four inch loud speaker aekamd edges acceptance of data and alerts the operator of pending problems. Hut most of all this "USED" terminal, with a little imagination, can be engineered to make the perfect home for an S-100 computer and video display; or attli sll£h! mollification will accept the Rockwell A1.M-5S micro/computer. !■ Ive volt regulated power supply is available for .in additional ISO. (Bee June Byte All units are In excellent condition. Original acquisition Deer S7O0. 22 lb*. H39.50 J m E DATA ENTRY SVSTEM PORTABLE DATA ENTRY SYSTEM These used data terminals were Originally desirned for retail store order en'. sya turns. The operator enters the inventory control number, merchandise ot hand and the unit price. After all pertinent data has been entered, the main v house 1b telephoned, the handset is placed in the acoustic coupler an ail [lie re- corded information is transmitted hack the master computer. Each system includes: Cassette drive unit; Removable hex keyboard with LED display; Five Gould "D" NiCads with charger; Acoustical coupler and DB29 cable. All units removed from service In working condition. Original cost over $2,500. Regulated Power Supply 5 VOLT 5 AMP $U?5 isior regulation outputs ttve volts at ■■ TTL hobby applications. SPC-PS1 Sankyo Magnetic Card Transport fhis Snnkyu card transport is capable of storing I M\d ret ri. -vim: over .100 characters of d " ,• sinele '_■ t^ 1 IIP style matmetie data Motorized mechanism palls the magnetic card across ihefoor channel r hi:ad in under two seconds. Ideal for any data processing application »h amounts of Information must be randomly retrieved. Original cost over Documentation and sample card Included. New surplus. SPC-SCR WESTER^ UMO^ ENCLOSURE Thei ufac- tured for Western Union by Uni- versal Technology, The enact purpose of the product is still » mystery but the enclosure Is Ideally suited for an S-100 mother- board wilh shielded power supply. Removable hood and plexielas front make this enclosure .in at- tractive home for any Iiobbv product. New surplus in fuclurv boxes supplied 22/44 edge connectors; UB 2SS coniinu foot grounded power cord and more 10 1/2" nQ 7/8" Shipping weight H lh $24.95^ All merchandise sulci by California Oigital is premium ^racle. Shinning; First five pounds $2.00; e;ich additional udd $.40 i orders 10% shipping. Kxcess will be refunded, ^tuuurnia residents add 6% sales lax. COD's discouraged. Open accounts extended to state supported educational institu- tions and companies with a "Strong Dun & Uradstrect. " Warehouse: 15608 Ingle wood Blvd. Visitors by appointment. TOLL FREE ORDER LINE 800)421-5041 TECHNICAL & CALIFORNIA 213)679-9001 CAliFoRNiA DiqiTAl Post Off if a Box 3097 B • Torrance, California 90503 '1J! MEMOREX i MEMOREX j MEMOREX MEMOREX MEMOREX B ■MEMOREX SUPER BUY NEW from INTEGRAL DATA Paper Tiger GRAPHICS *ll7U | The 460 Paper Tiger uses B do! ma cement of the dots overlap bath J [ spondunce quality printing. I rite printer a nine-wire print bead uses staggered needle rows to create the vei tleally overlappinc dots. The head Is driven bi-directionally under micropro- cessor control by a stepper motor driven mechanism. ' Two K " buffer allows the printer to accept the entire content of a 3.920 charac | CUT screen. With ( ;raphics suggested retail price S1.39S 27 lbs. PRG-460G HEWLETT PACKARD 2650 This self contained package THP 1VEC Spin writer 551(3 P/S *2"79 ['he woni processing quality Sptnwrlier prints at speeds upio 15 one utters per second. The Model SSH P/S is supplied with both parallt md H5-332 serial tat or fasten, Use Included is the tractor feed me im.-tm, .ilonj; with print thimble mi! ribhon. FHh-561BPfl 70 lb: ievboard lh.SH> Model fif.20 I'/S available i'2U:i:j. FUN-."i52f) 1'S 75 lb: JEC V-300 "Word Processing Daisy Wheel Printer ♦1595 in ably priced letter quality prlntei S characters per second. Full 130 prim posilit '130" 1 horizontal. 1/48" vertical. sea standard Dlahlo brand interchang-ibl.- deia] in -1 limj'j CPU iiii,-;i-i.iprticetisor controlled. Iiiti onnector. Shipping 5B lbs. PRV-300. TELETYPE MODEL 4 3 4320 KEYBOARD MODELS TTL aerial output AAA $ 995 RS232 serial AAK 1050 Friction 80 column AAE 1100 Friction 80 RS232 AAL 1195 Bell 103 Modem AAB 1495 Tat? EPSON MX-80 *495 misti. adjusts to accept ten It ivide eonuiiuniis paper. Uei.uiren "Eight bit" nies type parallel Interftcing. PRE-MXB0 17I.li CEnTRDniC5 730 $595 737 $750 Centronics; 730 and the 737 are capable Of accep-.in, Office letterhead or pin feed continuous forms. it resolution the 737 Implements a nine wire dot irlnl head. Parallel Interfacing. Add SBS for PRC-730P (S). PRC-737P (S) 17 lbs. 26 Megabyte Hard Disk Drive from George Morrows Thinker Toys Qher .'.lorro* Products. HJluonal hard disk S3SSU sens 2l> 1 drive DSD seus 2D :• drives lti27 SCU1 2*2 1 drive 1330 Dis: Jockcv 21' controller l)is< Jockey 1 Controller Wit herd dish Controller Switchboard interface "New" Multiboard M-in iv.i Meg ibyte hard AMPEX DIALOGUE 80 CRT TERMINAL 5 995 from"ilie Ampex Corporation. The Dialogue BO features removable keyboard ayable two pages (four optional) dual program keys, half intensity protected fields "and status line. Transmits data either block, line or character mode. Excellent value. VDT-D80 shipping 47 lbs. BMC VIDEO MONITOR $ 259 ISphOl < Mill somposit video input make the BMC KG-12C ..n ideal monitor for anyone requiring ■ugh resolu'ion 12" display, iiact plastic enclosure assures that the BMC monitor is a ragged where instrument, lor added protection the unit is equipped with removable smoked non-glare olexit'las screen. VUM-HMC 18 lbs. direct connect Your Choice MODEM $169 Direct connect modems eliminate loss of Information due to the car Don compress! associated With acoustic modems. Choose either of these two j;reat units. Tin- Universal Data Systems 1031.1' is switch selectable b-Kween answer and ort taatc o s. lullv Hell 10.1 compatable. Directly connects lo the new modular telephone |nek. mo ! powered from the telephone line. No need to locate modem proximity to AvC power receptlclo. MOD-1Q3LP 3 pounds. V/SA All merchandise sold by Calif on- Shipping: First five pounds $2.00 Foreign orders 10% shipping. E) California residents add G% sale? Open accounts extended to state i ia Digital is premium grade. each additional add $.40 cess will be refunded. tax. COD's discouraged, jpporled educational institu- tions and companies with a "Strong Dun & liradstreet. Warehouse: ir>608 Inglewood Rlvd. Visitors by appointn Circle 353 on inquiry card. nt. ACCESSORIES FOR THE COMPUTER CALIFORNIA COMPOTEH SYSTEMS Arithmetic Processor 7811 B/C $319 Asynchronous serial interface 7710 129 Centronics Interface card 7728 95 12K PROM Module 7114 69 Calender/Clock. Bat. back-up 7424 99 Parallel interface 7720A 99 Programablo Timer 7740A 99 Analog/Digital converter 7470A 99 MICROSOFT PRODUCTS Apple to Z-80 CPU card 379 D. C HAYES PRODUCTS Micromodcm for Apple 319 COMPUTER STOP PRODUCTS Double Vision I B0 Column Video 250 INTERACTIVE STRUCTURES 10 Channel A/D card AIO/2 275 MOUNTAIN COMPUTER PRODUCTS Intro X-10 system for BSR J2; Intro X-10 card onlv II IS channel All/DA 8 bit 3! Apple Clock batten' back-up 21 Supertalker SD200 %' ROM Plus with alter H ROM Writer/Programmer 1 APPLE BRAND PRODUCTS Apple Language card Floppy disk with controller Floppy disk without controller Apple parallel interface SSM MICROCOMPUTER Dual serial parallel interface AiO SORRENTO VALLEY ASSOCIATES 8" floppy controller (Pascal) 450 S-100 BOARDS Assembled • Tested • Burned-in MEASUREMENT SYSTEMS Dynamic memory IJMB-6400 S770 Dynamic memory D MB -8206 700 GODBOUT/COMPUPRO Dual B088/B085 16 bit CPU 375 Z-flO CPU 24 bit address 4 MHz 239 Sialic RAM 32K (Alpha Micro) 575 Spectrum color graphics board 329 Interfacer II I/O board 199 SEATTLE COMPUTER PRODUCTS 8086 16 bit CPU 2 card set /86 dos 595 CALIFORNIA COMPUTER SYSTEMS S-100 Mainframe 220OA 329 Disk controller/2.2 CPM 2422 329 Z-80 CPU 4 MHz DMA 2B10A 250 DIGITAL RESEARCH 32K 2716 EPROM board 99 EPHOMS for above 2710 16 req. 13 CALIFORNIA DATA CORPORATION A/ 1) board 10 channel 12 bits QT COMPUTER SYSTEMS Real time clock /calendar 135 MORROW /THINKER TOYS Multiboard "NEW" Daisy wheel port, real time clock, power on jump, program interrupt com 'I 3P/3S $37 Switchboard interface 4P/2S 21 Disk Jockey 1 disk controller 19 Disk Jockey II double density 37 SD SALES PROM-100 programmer Video display board 8024 Versafloppy 3740 controller MULLEN PRODUCTS Extender board/ LorIc probe (kit) 4 Relay Opto/control board 14 D. C HAYES PRODUCTS Micromodcm s-ioo FCC register 37 ARTEC ELECTRONICS Wire Wrap proto board WW/ 100 2 General Purpose prolo GP /100 I CALIFORNIA DIGITAL (10B6 CPU 4K on board static RAM 4! TELETEK SINGLE BOARD COMPUTER FLOPPY DISK CONTROLLER 1-lJC-l features the X.-B0 CPU I with the NEC 765 floppy ilisk •oiler. The board SURpOrtS both e or double density 9 1/4 or 8" drives. Two serial (4r>-960Qbd) wo parallel pons add to the Qex- uiilli; board computer, features are realtime nip to monitor, sectored ■oiling ; ■\ this _•; f.able nf (. ■nal 3 Winchester hai jwer Supply the 16 El'RUMS. s 695 S-100 Mother Board $35 Quiet Buss 8803-18 18 slot IMSAI TOLL FREE ORDER LINE (800)421-5041 TECHNICAL & CALIFORNIA 213 679-9001 7400 SN7400N SN7401N SN7402N SN7103N SN7404N SN7405N SN7406N SN7407N SN7408N SN7409N SN7410N SN7411N SN7412N SN7413N SN7414N SN7416N SN7417N SN7420N SN7421N SN7422N SN7423N SN7425N SN7426N SN7427N SN7429N SN7430N SN7432N SN7437N SN7438N SN7439N SN7440N SN7441N SN7442N SN7443N SN7444N SN7445N SN7446N SN7447N SN7446N 3N7450N SN745IN SN7453N SN7454N SN7459N SN7460N SN7470N SN7472N SN7473N SN74 74N SN7475N SN7476N SN74 79N SN7480N SN7481N SN7482N SN7483N SN748SM SN7466N SN7489N SN7490N SN7491N SN7492N SN7493N SN7494N SN7495N SN7496N SN7497N SN74100N SN74107N SN74109N SN74116N SN74121N SN74122N SN74123N SN74125N SN74126N SN74128N SN74132N SN74136N SN74139N SN74141N SN74142N SN74143N SN74144N SN74145N SN74147N SN74148N SN74150N SN74151N SN74152N SN74I53N SN74154N SN74155N SN74156N SN74157N SN74158N SN74I60N SN74161N SN74162N SN74163N SN74164N SN74165N SN74166N SN741G7N SN74170N SN74I72N SN74173N SN74174N EN74175N SN74176N SN74177N SN74179N SN74180N SN74181N SN74182N SN74184N SN74I85N SN74186N SN74188N SN74190N SN74191N SN74I92N SN74I93N SN74194N SN7A195N SN74196N SN74I97N SN74I98N SN74199N SN74221N SN74251N SN74273N SN74279N SN74283N SN74264N SN74265N SN74290N SN74298N SN74365N SN74366N SN74367N SN74368N SN74390N SN74393N SN74490N CD4000 CD400I CD4002 CD4006 CD4007 CD40O8 CD4009 CD4010 CD401 1 CD40I2 CD4013 CD40I4 CD4015 CD4016 CD40I7 CD4018 CD4019. CD4020 CD4021 CD4022 CD4023 CD4024 CD4025 CD4027 CD4026 C04029 C04030 CD4031 CD4032 CD4034 CD4035 C04037 CD4040 CD4041 CD4042 CD4043 CD4044 CD4046 CD4047 CD4048 CD4049 C04050 CD4051 C04052 CD4053 CD4055 CD4056 CD4059 CD4060 CD4066 CD4069 CD4070 CD407 1 CD4072 CD4073 CD407S C04076 CD4077 CD4078 CD4081 CD4062 CD4085 CD4089 1.10 3.95 2.95 CD4093 CD4094 CD4098 C04099 MCI 4408 MC 14409 MCI4410 MC14412 MC14415 MC144I9 CD4501 CD4502 CD4503 CD4505 CD4506 CD4507 ZD4508 CD4510 CD451I CD4512 CD4515 C04516 CD4518 CD4520 CD4555 CD4556 CD4566 74CO0 74C02 74C04 74C08 74C10 74C14 74C20 74C30 74C32 74C42 74C48 74C73 74C74 74C85 74C89 74C90 74C93 74C95 74C107 74C151 74C154 74C167 74C160 74C181 74C1B3 74C164 74C173 74C174 74C175 74C192 74C193 74C1 95 74C922 74C923 MM80C95 MM80C97 74LS00 CMOS 99 295 2.49 2.25 12.95 12.95 12 95 12 95 8.95 4 95 1.39 3.95 1 69 1.65 1.85 1 19 2.49 3.50 2.10 2.39 2.30 239 2.39 2.59 2.75 2.75 2.39 2.39 2.39 7.95 6.95 1.50 1.25 74LS00N 74LS01N 74LS02N 74LS03N 74LS04N 74LS05N 74LS08N 74LS09N 74LS10N 74LS1IN 74LS12N 74LS13N 74LS14N 74LS15N 74LS20N 74LS21N 74LS22N 74LS26N 74LS27N 74LS28N 74LS30N 74LS32N 74LS37N 74LS38N 74LS40N 74LS42N 74LS47N 74LS48N 74LS51N 74LS54N 74LS55N 74LS73N 74LS74N 74LS75N 74LS76N 74LS78N 74LS83AN 74LS85N 74LS86N 74LS90N 74LS92N 74LS93N 74LS95N 74LS96N 74LS107N 74LS109N 74LS112N 74LS113N 74LS114N 74LS122N 74LS123N 74LS124N 74LS125N 74LS126N 74LS132N 74LS136N 74LS138N 74LS139N 74LS145N 74LS148N 74LS151N 74LS153N 74LS154N 74LS155N 74LS156N 74LS157N 74LS156N 74LS160N 74LS161N 74LS162N 74LS163N 74LS164N 74LS165N 74LS166N 74LS16BN 74LS169N 74LS170N 74LS173N 74LS174N 74LS175N 74LS181N 74LS190N 74LS191N 74LS192N 74LS193N 74LS194N 74LS195N 74LS196N 74LS197N 74LS221N 74LS240N 74LS241N 74LS242N 74LS243N 74LS244N 74LS245N 74LS247M 74LS248N 74LS349N 74LS251N 74LS253N 74LS257N 74LS258N 74LS259N 74LS260N 74LS261N 74LS266N 74LS273N 74LS275N 74LS279N 74LS283N 74LS290N 74LS293N /4LS295N 74LS298N 74LS324N 74LS347N 74LS348N 74LS352N 74LS353N 74LS363N 74LS365N 74LS366N 74LS367N 74LS368N 74LS373N 74LS374N 74LS375N 74LS377N 74LS385N 74LS386N 74LS390N 74LS393N 74LS395N 74LS399N 74LS424N 74LS668N 74LS670N 81LS95N B1LS96N 81LS97N 81LS98N LINEAR 78H05 78M06 78M.G. LM105H LM108AH LM300H LM301CN/H LM304H LM305H LM306H LM307CN/H LM308CN/H LM309K LM310CN LM311D/CN/H LM312H LM317T LM318CN/H LM319N/H LM320K-XX- LM320T-XX" LM320H-XX' LM323K LM324N LM339N LM340K-XX- LM340T-XX' LM340H-XX' LM344H LM348N LM358CN LM360N LM372N LM376N LMG77N LM380CN/N LM381N LM3B3T LM386N LM387N LM390N NE531V/T NE555V NE556N NE561T V NE5G2B NE565M7H NE566H/V NE567V/H NE592N ; LM702H LM709N/H LM710N/H LM711N/H LM715N LM723N/H LM733N/H LM739N LM741CN/H LM741CN-14 LM747N/H LM748N/H LM760CN : LM1310N LM1458CN/N MC1488N MC1489N LM1496N LM1556N LM1800N LM1820N LM1850N LM1889N LM2111N LM2900N LM2901N LM2917N CA3013T CA3018T CA3021T CA3023T CA3035T CA3039T CA3046T LM3053N CA3059N CA3060N CA3062N LM3065N CA3080N CA30B1N CA3082N CA3083N CA3086N CA3DB9N CA3096N CA3097N CA3130T CA3140T CA3146N CA3 1 60T CA3190N CA3401N MC3423N MC3460N SG3524N CA3600N LM3900N LM3905N LM3909N RC4 1 3 1 N RC4136N RC4151N RC4194 RC4195 ULN2001 ULN2003 SN75450N SN75451N SN75452N SN75453N SN75454N SN75491N SN75492N SN75493N SN7 5494N ADW\NCED COA\PUTER PRODUCTS BECKMAN Digital Multimeters p9 % The TECH 300 nas .i D S»i Voc ,i«urjcy im an dtluc leaWM (ml willwiil insl?- Ohms'" rriHyluncl-on ui the 10 UpMlM ^rv^- : . * I TECH 300 Dignai MuRmwhi TECM 310 Digital Mullimnlei TECH 330 Digilnl Mullimolor VC-201 Vmyl Carrying Case DC-202 De-iu.e Carrying Case HV-21 1 High Vollage Probe HP-221 RPProt* Cl-231 AC CurtWll Clamn DL-24 1 Deluio Inst Lead Kil 7L-242 Spare Tesl Leads S100 SI 30 $189 ■ffWM VISTA LiTlrl COMPUTER yra^aa company APPLE™ 40 CHARACTER TYPE-AHEAD BUFFER Hi-Speed Serial UO Centronics Pfniet I/O Applesoll II Firmware Apple dock Introl X-10 System Inlrol X-10 Controller AH Music Synthesizer 16 Ch Analog Input 2 Ch Analog Output 13- Key Keypad Visi-Calc • Apple® II 16K Apple® II Plus $1 1 DISK SYSTEM SPECIAL Apple II Plus W/48K Supermod Video Modulator Disk II w/Controller Integer Based ROM Card. ACP PRICE S1969.00 0S65 Oigi-Seclo* $349 00 Integer ROM Card Apple Graphics Tablet 67500 Prolo Card OC Hayes Modem il 34995 HSR Modulator Or:* II WCrnlrUw 4 Po$33 S18900 180.00 18900 26900 17995 26995 25995 24995 164 95 11995 12500 Disk II Pa«a' Lang System Parallel Printer Card Commun i canons Card Business Soil warePkg Corvus 10 Megaoyle Drive 4625 00 459 00 450 00 16500 189 00 625 00 16K Upgrade K>\ Desktop Plan 8 Floppy Controller Heuristics SpeecWab Ron .plus + Supe'lalkei Cashier 50 SI 89 00 2195 2995 . 54.95 54 95 9B00 35000 179 00 169 00 27900 25000 Jappkz^ $3gg5 A • Apple III Option A; Apple II 96K. „ _ . _ „ Inlormation Analyst Package. • APPle 'I' Option C: Same as 1 2" B/W Monilor $3995.00 Option A Pius: Disk II for Apple 111, • Apple III Opiion B: Same as Silentype Thermal P f inter $4785.00 Option A Plus: Disk II lor • To substitute 1 28K Apple III tor Apple III $4395.00 96K Apple III Add $450.00 NEW APPLE PRODUCTS ■ AFVLE FAN" - Cures thermal rjrotiems (rom mttaoHtea •nadires designed specifically lor Anne $49 95 • 'BIT 3' - New 80 > 24 Video Board lor Apple Completely compaieie with Pascal S3?9 95 • "BAH WAND" hcwlctl Packard HEDS-3000 Bar Code inlolacal lo Apple S19900 • "SEC APPLE A/0" - 6 Channel A/D inlertace comDrei^y assemored and lesied S9950 t "APPLE FORTdAN" S175D0 ■ "APPLE CRyPIEXT lot data cncryplion and seewty M490C "B2/A2" GfapflKa Inlertace Card by Base 2 S15995 B" Disk Drws tor Apple Controller, DOS. Two B" flrwes cab.net anJ cade J145000 MOOMODEM - DC Hayes $31995 "D1GISECT0R" Converts video input to HfRes qraphes S34995 Can r of ma Ml crop rod ucl* i/iilC*rC KnypaOi Numtwrtc koypid with «p«ce. wwco ESC - and ■ lay* lot VWOale compall- BIHty SI 69.00 • DOS 3 3 Upgrade Kits 23% more suxaoe m 16-secux lor mat 165 00 • Mcuntan Hardware Muse Board best yet - 16 channels 155000 • Conlroiier 1 1 Revtsion m 20°^ overall processing speed release and supports standard printed Hnliced disk handing Addilronal error erecting Imcvoved nanuai Vendor hie eipanded $14500 • Pascal Revision Kit Adds eiecutrve and ctuimnp capabililies lo Pascal environment $6500 • Mountain Hardware Eipansion chassis 8 more Sims lor Apple Hardware or software selectable Includes cower supply Avarl Soon • Smart Term Appte 80 > 24 Vtfec Card 1619.00 • Symie. X-10 $34900 • Apple Siienlype With Apple inteHoem iniedace Card $54900 • NEW CaMorria Compuier Sysiems APPLE dock Orty $124 95 • NEW 2-80 Soflcard to APPLE CPH 22 & M BASIC 50 J32500 RETAIL STORES OPEN MON-SAT mammm P.O. Box 17329 Irvine, Calif. 92713 Direct Order Lines: (714) 558-8813 (800) 854-8230 or (800) 854-8241 POttft'BLACrUACK ROULETTE HORSE HACIMG SUBBATTlf ARMOfi (UTILE SPACE BATtLE SEA BAntE ABCAOC FOR INTERNATIONAL ORDERS: 1310 E. Edinger (714) 953-0604 Santa Ana, CA92705 TWX: 910-59S-1565 402 BYTE April 1981 AEWVNCED^— COMPUTER QDUCTS "V-DRIVE" THE LAST WORD IN 8" Fiom-OISK ENCLOSURES s-ren MmMH re 9ifl«! law M cruse, «i frrefi starring an i«a • S orate ap«*» Hon Ci to « irw^j^i • tfYJj»*MQLa%CB>B«alfiCstC UxoH'JLmlOrjUAxinHra • ***mJ S»*g* Rent Md nar • Mm NOW SAVE ON TRS 80 ADD-ON ONLY $299.00 ! DRIVE CABLE 29.95 2 roR 279.00 , I DRIVE CABLE 39.95 MINIATURE CO MPUTER LMkrOfkCj Computer BAjto 1KKI1 149.00 \ 2KKIT 169.00 ' Manual 10.00 ATTENTION VIDEO HOBBYISTS!!! * BOX BUILDERS * USE AS REMOTE TUNER/TIMER * FULL SCHEMATICS AVAILABLE * FOR ONLY $5.90! - FREE W/PURCHASE A RflCnH Sc«oal Puirnas* Allows Us To Present The Foltovunq NEW. UNUSED COMPONENTS FriB Til Raimti ll*M Cimtti Ricirdir I IJHF.VHF Iutp SuMSSenYJy *ajl a« MM anil ViJ.ii Df nortiHalot ill rng ? Hf Mooiiiaio *ifiAua«*V«jH)ini.,ii MU. run CtonnH 3 or 4 OuDul 3 OfftH rice!- Module AM7PM Fluoresce-" Re**iit (Green) 4 3M0»ifnlo'irinmMi1cfw^ 74 95 MeMEitXOTl«95 Call FOf Volume Discounts FLOPPY- LOW cost DISK SUBSYSTEM Siemens FDD 1 20-B (21 VISTA Floppy Control- ler (S-100). Case. Power Supply*. Cable CP/M Disk Operating System Assembled 4 Tested -'..:■■■■ ■.'.-■■.. -i ■;,.■;-■ . *14M.0O .CHECK Dim floftt 1111 ra.ciHG on this rut* SAVE S300.00 (SI 79900 VALUE) WATANABE MIPLOT RAM BOARDS SPECIAL 10K AJUIr Mil. Dynamic RAM Hoards Aeaem. 1 TitWd 11 10.05 Untested J 05 OO 16K FLOPPY DISK DRIVES TandomTMIOO-1 5W." DM Drtva 249.95 MPIBai-5V.*0irme*a 239.85 Shugarl SA4O0-SW 35 tracks 20*00 Shugarl BOO/601 R 8" 440.00 Stamens Shugart Compatible Mode FOD-120-80 42900 PERSCI Modal 277 Dual 1 19500 WANQO/SIEMENS5*-Ortve 200.00 MP1 062 B\d*Doal 348.00 WANQO/SIEMEMS 282 Oirral 5V 306.00 WANQO/9IEMENS82 200.00 MPI 91 Double Tree* Oanalty S-ng-a SkM. 80 Track* . 379O0 MPI 02 Double Trick Penalty DoubK Side. 1 BO Track. . . ■ 478.00 9601 9602 9603 9604 9605 9616 9617 9620 9622 9627 9629 9629A 9630 9640 96» 9655 96103 96702 16 Slol Mother Board Card Cage B Slot Mother Board Power Supply DC Input Power Supply Utility Prolo Board Anlh. Proc/Memory Module Buttered Utility Prolo Board 32K EPROM/RAM Module EPROM Programming Head 16 Channel Parallel i/O Module Serial-Parallel I/O Module 16K Sialic RAM Module 470ns 32K Static RAM 450ns 32K Static RAM 200ns Card Extender Multiple Programmable Tuner 8 Channel Duple* Serial I/O Mod. Intelligent Tape Controller 32/32 I/O Module Contact Closure Module 175 00 75.00 1 00.00 275.00 32500 39.00 49500 49.00 250.00 250 00 29500 325.00 39500 695 00 895.00 68.00 395 00 39500 550 00 27500 350.00 The Vista V30O Printer SUnOiMJ tb in •Ilsr" $1895°° THE VISTA V-20O FOR EXIDY Price Slaning as low as 11 199.00 Stan* onrt Unaka thai Cajtotf CatnaKmx •**>■ Pita VPQ0E20 «00 ?Bmt ?5itK 119900 Smote Hon WOO (■?? 800 2 pn* 75 % 154900 Oouw Head VTOOEJO 600 ] Dnvt 32l«, f.7400 Single Hrarj V200E3? t?MSG 30n«e Jj Urs 199900 Doutrerwa] EXPANDORAM II MEMORY KITS * Bank Selectable + Uses 41 16 200 ns * Write Prolect _«,* Power BVDC ±16VDC * Phantom HgSets *■ Ud to 4 MHz Expando 64 Kil (4116) Assem & Tested Add S50. 16K $249.00 48K S435.00 32K $289.00 64K $505.00 "^3?9^Rs5o7aPPLE^39!9^ memory expansion kits. 4116's. 16K (200/250 ns.) B pes lor S30.95 w/in5tructions 8 jumpers Call For Volume Pricing * Special TRS80 Schematic S 4 95 * Expansion Interlace Schematic S 4.95 * Exoansion Interface Conneclor 7 95 CENTRONICS PRINTER Modal 737 • Centronics complete printer ■ • The 737 has everything. Check and compare the leatures • New low price $835.00 32K STATIC RAM BOARD S-100 16K 4MHi KIT 159.0! 16K4MHzAAT .217.951 32K 4MHz KIT ...289.95 I •J [ 32K 4MHz AiT 348.05 I H Bare Board 30.05 I - .m.^wilnuii^ 00.05 | BASE II PRINTER^ ^TTc!! a 60 Lmos Per Minute flS Mlmo; a 115/230 VAC. SO Jk\% .— — -3>-^ or 60 Hj f^» ~~~~"^&~^ • 72. 80. 96, I 20 or P"*ajtL-^«l**^^--^ •&8SSS* ^^-^1 BEG1799O0 | WtTH ALL OPTIONS ACP PRICE $699.00 | Option "M" Terminal Screen Butler 1 1920 Cha' I J50 00 Option V High Speed Paper Advance 8 Graphics 50 00 Opuon 'T Tracio- Feed 5000 UV "Eprom" Eraser . Model UVs-1 1 E $60.95 ) Holds 4 Eprom s at a lime I Backed by 45 years experience Modal S-52T... S325.0O Professional Industrial Model S-100 MOTHERBOARD SPECIAL 8 slot expandable w/9 conn. rgfl $69.95 NOW $52.95 SHUGART DRIVE 449.00 ACOUSTIC MODEM NOVATION CAT"" O3O0 BauC 'D' CAT MODEM NOW AVAILABLE SI 00.00 MONITORS Uanyo VM 4509 9"BAV Sanyo VM 4212 1 5" B/W Sanyo 6013 1 3" Color DATA BOOKS • COMPUTER BOOKS 19S0 IC Master INTEL Da ia Book .. INTEL MCS 85 Manual - - SALE a OIBOBWf BOOK* a IALE Inlro to M.. .,>■■ Vol Intro to Micros Vol. I 8080 A Prog. ramming 6800 Programming Z80 Programming Vol II Some Heai M coprocessors w/8-ncer Vol. Ill Some Real Suppon Devices w/Bmdor Intro lo M.c'os Vol "' BOB6 Programming Z8O00 Programming Inlro. lo PaacaJ 750 tela 12SO 1250 1250 1250 1600 27 50 27.50 IB 50 14 95 14 05 14 95 SALE • SYBEX COMPUTER BOOKS • SALE 6502 Games . SI 2 95 tnlro to Personal A Business Compuling 12.95 Mircoorocassors From Chips to Systems 1 2.95 Microo'ocossor Iniertaciog Techniques 12.95 Programming the Z80 . . 12.95 Programming Iho 28000 . . 1295 Programming Iho 6502 12 95 6502 Applica Irons Book .... 12.95 CPMHandbook 12.95 FIRST TO OFFER PRIME PRODUCTS TO THE HOBBYIST AT FAIR PRICES! 1 . PrOVeil Quality Factory tested products only. 2. Guaranteed Satisfaction 3. Over $1 ,000,000.00 Inventory 1981 CATALOG NOW AVAILABLE Send S2.0O for your copy of the most complete catalog of computer products. A must for the serious computer user. MICROPROCESSORS zao Z60A F-6 138501 2650 TD1B02 BOBOA BOBOA^MHi SALE 8085... 1695 1895 1395 2901 290W 2903 40il Sup TMS 9900JL CPI600 6502 6502A IM6I0O 29 95 49 95 39 95 6800B2 0MH; 6802P 8035 8039 8755 8748 6809 19.95 19 95 1995 49 95 69 95 37 95 69 95 ADVANCED SUPPORT AM95I I Anlti Procr 9512 Anin Processor 9513 Linn Timing AM9517 DMAContrr. AM9b'9Univers. I 75.00 175 00 79 95 18 95 1895 Z-80 SUPPORT CHIPS Z80PIO Z80A.PIO Z80CTC Z80A-CTC Z80-DMA Z80A-0MA Z80-SIO/0 Z80A-SIO/0 2 5 MHi 4 0MHi 2 5 MHi 4 0MHr 2 5 MHl 40MHI 2 5 MHz 4 MHZ 2 5 MH; 8 75 12.95 29 95 36 95 35.95 39 40 35 95 39 40 Z80-SIO.M Z80A-SIO/1 Z80-SIO/2 2 5MHt 280-SI0/2 4 MHi 8080/8085 SUPPORT 24 95 39 40 HI !!.!„■« I 56 I/O (1755 I/O With Eprom 8202 Dyn Ram Com 8205/748 '38 Decoder 82i2 8bni/o 82 14 Pr.or.ly Inl 8216 Bus Driver . 8224 Clock Gen 8224^4 (4MHi| 8226 Bus Driver 8T26 Bus Driver . . H22H !?ys Control. B23B Sys Conl 8251 Prog I/O 8253 Inl Timer 8255 Prog I/O 8257 Prog DMA 8259 Prog Int 8275 CRT Conl roller Prog KeyDoard 64 95 34 95 3 95 2 75 5 25 2 75 2 95 9 75 395 2.95 5 50 5 50 6 95 1295 650 16 95 17.95 49.95 15 95 SBOO SUPPORT CHIPS 5810 128x6 Ram. 4 75 6820 PIA 5 95 6821 PlA 6 50 6828 Priority Int 19.95 6834- 1 5 1 2 i B Eprom 1 6 95 6845/MP46505 CRT Com. 39 95 6847 Color CRT 49 95 6850 AClA 5 95 6852 Serial Adapter 5 95 6860 Modem 1095 6862 Modulator . 11.95 E371A IOMHiOSC 2595 6875 . . 6.95 6880 Bus Driver 2.95 MC6848B 19 95 68047 24 95 SHIFT REGISTER SALE 2504V 1 49 2525 1 49 2507V 1 49 2527 . 1 49 2517V . 1 49 252B.. 1 49 2524V 1 49 2529 l 49 2533-. 149 0902 SUPPORT CHIPS 6520 PIA 7 50 6522 Mull 11 95 6i30O02.003.004.005 21 95 6532 1995 6S51 19.95 PROMS 2708 450 ns B 25 2708'G650n 5 7 50 1702A 4.95 2732 44.95 2716-5V 14.95 2716-SV. 12V 19.95 2758-5V 1995 S203AQ 1395 5204AO 14 95 IM5610 3.90 B2S115512 x8(TS) . 16.95 82S12332 x8 . 4 90 82S126256«4 4.90 82SI292S6x4(TS).. . . 4.90 825130 512«4(OC) 6 50 B2S23 695 825131 14.95 82S137 1495 745387 8.50 745471 12.96 74S472 12.95 74S570 14.95 74S571 14.95 NOTE: WE PROGRAM PROMS CHARACTER GEN. 2513O01 (SV) Upper 9 50 2513005 I5V) Lower . 1095 2513.ADM3)5V)Lower. ... 14,96 MCM6571 11.75 MCM6571A . II 75 MCM6574 14.50 MCMGS75 14.50 MCM8874 14.05 U ARTS/BAUD RATE TRI602BI5V 12VI 3 95 AYV013I5V 12VI 495 1 AY5'014A/16I2(5-14V| 6 95 AY5I01SA/1863I5VI 695 TMS60H 15V 12V| 553 IM6102 795 IM6403 8.95 2350 USRT 9 95 l671BAstros 24 95 KALI TK14T3B O.OB MC14411 11.95 4702 14 95 WD 1 94 1 9 95 COM5016 ...16.95 AMI18S3 7.05 INS 8250 15.86 KEYBOARD ENCODERS AYS-2376 13.75 AY5-3600 13.75 MD0165 9.95 74C922 9.95 STATIC RAMS 2IL02 450ns /tBA*A 1 30 1 25 21L02 7S0ns 1 ^0» ) ' ? 9 ' 5S 2112-1 V£9'295 ?8S 99 155 ?65 2101-1 290 27( ;tl4L250ns [40461 6 50 5 91 Zl l4L-4Mm (4045) 5 50 5 25 4.7S 4044 4SOni 5 gs 595 EMM4200A 9 75 8 ?5 7 95 EMM4402 '95 7 25 AMD9U0r31 1295 1195 1101 1 95 ' 7S P2'25-9J4?Sl4bnsi 995 8 35 '0 25 8 25 B5lfl IK . t CMOS 795 795 7 25 Zi47LnwPo»er4KSianc t995 t895 1695 93415 995 895 8 50 TMS.10.1li 1 1 95 1095 10 50 DYNAMIC RAMS JI6/4tlf, l6Ktl6P.nl Seio 95 "bo all RAMS 66 °4 5?w i?45$159.95soo:' '95 1 50 SOCKETS ■ Pin. [ WIr. Wr. D 3 linl M 20 38 62 20 ?2 29 79 110 43 JO 60 MO 169 ZERO INSERTION FORCE 16P" S550 24 Pj.i S7 50 JOF'.n SHI .'5 FLOPPY DISK I/O LED READOUTS OtMM 10D Hod Currm And* FND157 1J7 Hal CHTfTi CillW* FND501 SOD RM M)0 Had fh(i:>;i;i',ii) IjOO RM Ccmm AfKd- IHBbM 500 RM Comra AruHel-Hl FNtJiJC S00 Own Conn Ciwor rrjDSbO fNDa03l8W) 800 nw FND807(BI0 800 RU HPS087 7Mt 600 BM HPSoa2 7KX 600 U 4 1 7 Sql Dfll BHP HP50B7 773I 300 R« TIL305 nra IIL308 270 RM NitntnrjJ DrsWi ComrTi Anrbp Lftt 01 100 Orttn ttwTll» C* Irt DP 300 Gy««i Ccnm CiNdc FUgnt DP 300 YNIO* Conm Aixiof Ri^it UP IC SPECIAL PURCHASE LF 13508 JFET Analog Multi 8 btl 8 95 ICM 7045 Precision SioDWaich 23.95 CMOS LED Stopwcich/Timer 19.95 ICM 7207 Oscillator Conlrollar 7.50 Seven Decade Counter 1 B.95 ICM 7209 Clock Generator 6 95 ICL 7107 3'i Digil A/D (LEO) 14 95 MC1 4433P 3 1 j Digil A/0 Converter 1 3 95 ICL 82 1 1 Voiiage fleierence 1 95 LM 1B50N G'Ound Fault IC 3/1 00 LM 290ON Quad Amplifier 2/1 CO LM 2917N F.eq 10 Voll Conv 2/1 99 AY-3-3550 4'. digit DMM 24 95 AY-5-3507 40MH' DVM 9 95 MEM 4963 Mostel Smoke Deleclpr 1 1 95 27S08 32 . 8 Prom |IM 56001 2 95 G1 15M 6 channel Mostet 1 49 ULN 2003A 7 channel Driver .99 2101AL-4 195 MCM 14505 64 On Sialic Ram 695 MOC 1003 (4N28)Oolo Coupler 3/1.00 SPX33 OpIO Coupler 3/1.00 IH 5045 CMOS Switch DBST . ,450 VA 3045 Trans Array . 1 ,25 TR 1 402A UART 1 .85 MR 1007 Dyn Mem Shrtt Reg ,, .395 5736 Calc. Con CtrOuH . 2/1 .90 5763 Cite, Con Circuit 1.96 5318TVCh. Dlap CUCuN - 4 50 BOBOA 8 Bit CPU 4 95 82S21 32 x 2 Static RAM 2/1.99 8700 CJ 8 Bit A/D 90S 2758 5V-2708 EPROM 12,95 MM5280/VPD411/C2 107/TMS 4060/ 4I01 Dynamic 22 Pin RAM 1.76 6604/VPD 41 4/402 7/2660/MK 4096/ 4Kx1 Dynamic 16 Pin. 1.95 New Nallonal Clock MM 58187 Real Tlma 1 9.&C 7520/25 50 LM 387 I 25 1488/1489 2/1 99 LM 3302 3/1 99 MK50'4Calc 3/199 LM 4558 LM323K 4.95 MC1372 . 8.95 MM5298-4A/B . 2.95 RC 4 1 36 PC 4131 DAC100 15.95 VERBATIM DISKETTES 100% CERTIFIED ERROR-FREE1 1771-01 8"4 Miniltoppy uPd372 Nec Floppy 1781 Dual Floppy 179101 Dual Floppy uPd 765rioppy A/D CONVERTERS 8700 8 Oil Binary Sol: StciorM IRS 80 elc IQMMr; MarrlHS Apr* at 15 Mac Hard Mciopoki (2S.05 tn*s 52501 52S-10 525- IE • 40 & It IMCX IHIILE BENtlTY- IIIBIE 5101 O ItA'WIWI "HKFflMHMN, "INC 577 01 Soil StciorM IRS BO etc S32 577-10 10 Hole Hud NS Apple etc 32 577-16 16HoltHnid Wcrcoots 32 a ig nu.cn Muni hied bouile Kilin i% 55001 Salt Sectored SA 450 MPI 52 8M 550-10 10 IHt HarrJ 8ASF. WAHGCO PJ 550-16 IGHrieHjrrJ Mcro> •" a r lHSCEITll-IEItlUETTEl FDBOO-OI Soil S>nc* Densily. 3740 S33 FDflOO-32 32 Hard Single Density Srug 33 FD8020T Soli OojDIe Oensrly 3740 44 FD85001 Soil Double SOW. Doit* Density 3740 49 VOLUME DEALER PRICING AVAILABLE MH *t JO 8TTTt*rf ITYIAN OAI I 24 95 4995 2995 36 95 49 95 8701 8703 8 b.l TS 9400 Voll toFreq Con, 8750 3'rOigil BCD 140BL6 6bil 3 l40BL6 8 0il 5 DACOI D to A S. DAC08 9 DAC 100 15 TV CHIPS/SOUND AY3B500-1 G Games B/W 4 AY385 15 Color Converter 2 AY38603-1 PoadraceGame B AY38606-1 Wipeoul Game 9 AY38607-1 Shooiing Gallery 8 AY3B9 1 Sound Generator 1 2 SN76<17?7ISoundGeneiator 3 MM5320/2 1 TV Synch Gen 9 MM5369 Prescaler 3 LMI8B9 RF Modulalor 3 MM57100 NSC Color TV 6 104CH 13 50 2200 1350 ./Audio 8 Hb 29.9: RF MSR Moduiat WAVEFORM GEN. B038 Function Gen 3 95 MC4024VCO 295 LM566 VCO 1 95 XR2206 Funclion Generator 5 25 SHIFT REGISTERS MMSOOH Dual25 .50 MM5056N Dual 256 .2 95 MM5060N Dual 128 2 95 2510ADual 100 1 95 2847 Quad 80 . 4.95 3341 Dual 80 4 95 3351 40x9FIFO 17 95 3357 Quad 80 6 95 9403 16 i 4 FIFO 9408 lOBn Seoul 3347 24 95 9 95 5 95 CTS DIPSWITCHES CTS206-2 CTS206-4 CTS206-S CTS206-6 75 CTS206-7 75 CTS206-8 75 CT5206-9 75 CTS206-10 CONNECTORS (GOLD) DB25P1RS232) D825S Female Hood Set w/Hood. Sale 22/44 W/W. S/T. KIM 43/86 W/W, S/T. MOT 50/ 1 CO S- 1 00 Connector « 50/100 S-100 Connector '. S750 2 95 650 NAKED PC S-100 Sound Board S34.05 Z-80CPU/(ithaca). . 34.95 8O80ACPU 34 95 16K Stale RAM (2114) 29.95 32K Static RAM (2114) 39.95 BK Eprom (2708) . 24.95 1702 Eprom Board 30.00 270B/27 1 6 Eprom 34,95 RBHltime Clock , 34.95 ACP Prolo Bd. (3M Conn.) . . . 27.95 Vector 8800 Proto 22.20 Vector 8803 1 1 slol MB. . . . 29.05 ACP Extender w/Conn. 18.95 13 Slol MolherBoard(WMQ 32.95 3 Sioi Mot herBoardfWMC). .29.95 8 Slol Mother (Ex oandabta).. 34.95 Proc-Tech Bare Boards. CALL ■VMC FloopvPCB 34 95 floppy PC8 IB' SHUGART) 30 B5 COMPUTER SPECIALS MSCO' tfUl* LIST SALE 995 'BS, Apple II Plu PET 2001-1 Ejudy Sccer Cromemco Sys II! 6990 6290 Hornon I w/32K CALL Pascal Microengme 1995.1595 IPSI 1620 Diablo RO 3295 2695 Anade«DP8000 995 875 CemromcsMicroS-1 595 525 Soroc IO 120 995 795 Teletype Model 43 1349 1 150 HiPIOI Plolli H.PIol Digili Alan 800 Alan 400 TI99/4 Laedei 12" Monitor Centronics W Trancom T-100 Trencom T-200 Sanyo 9" Monitor Sanyo 15" Monitor Sanyo 13' Monitor 795. 735 895 784. 999. 825. 549. 449. 1150.1025 189. 140. 995 899. 375 349 595 525 SOCKET SPECIALS 14Plrtw/w2L I .36 20 Pin w/w-2L 76 IB Pin art 18 22 Pin art 16 MPWiart 100/12,00 18 Pin art -....100/13.00 Cat lor vohinta orldna TERMS: Use check. M/C, VISA. AMEX, CB. or COD. COD requires 25% deposit. Charge Orders please include expiration dale. Foreign pay U.S. Funds. Order by phone, man or TWX. MINIMUM 110.00 Please In- clude magazine issue and phone no. SHIPPING USA add S2O0 lor first 2 lbs For surface add 30* lor addi- tional lbs. For air add 70« for addi- tional lbs FOREIGN: Add 1 0% ship- ping and handling COCsJI.eiexIr*. N01 raaponsible lor typoa. Soma Hems subfacl to prior sale. We re- serve hghl lo limrt quantities, soma Hems subject 10 predoua metal adder. Retail pricing may vary from Mai 1 Order. We reaerve The right to sub- RETAIL STORES OPEN MONSAT P.O. Box 17329 Irvine, Calif. 92713 Direct Order Lines: (714) 558-8813 (800) 854-8230 or (800) 854-8241 FOR INTERNATIONAL ORDERS: 1310 E. Edlnger (714) 953-0604 Santa Ana, CA92705 TWX: 91 0-595-1565 Circle 354 on inquiry card. BYTE April 1981 403 <* COMPUTER SYSTEMS J INC. 15620 South Inglewood Avenue l.avtndale. California 90260 (213) 970-0952 SYSTEM+ (8") QT SYSTEM + MINI- SYSTEM+ (5V4") The QT System+ is designed for both businessmen and engineers in accordance with the latest IEEE standards. Among other functions, it can be used for accounting and word processing, as well as a variety of scientific applications. The system will soon be available with MP/M® to allow multiuser, multi-tasking operations. This means, for example, that an engineer could be working on scientific applications in the lab while an accountant is writing payroll checks in the office. QT also offers a full line of business and applications software, ranging from a business package to word processing. Technical specifications: 4MHz Z-80A CPU • Dbl-sided, dbl-den. 5V4" & 8" floppy disk controller (handles both drives simulta- neously) • Two 8" dbl-den., sgl. or dual sided disk drives, expandable to 4 floppy drives • CP/M® 2.2 included • 64K RAM • Comes complete in single mainframe • EPROM/ROM in any combination to 8K • Two RS232C serial I/O ports • Two parallel I/O ports • Hard disk compatible • Real time clock • Std. 2K monitor program & disk routines included on ROM • Power- on/Reset jump to monitor program • 2716 (5V) EPROM programmer (software incl. on monitor ROM)(ext. 25.5V @ 50ma req.) • Uses Z-80A CPU vectored interrupts • Assembled, tested & burned •Documen- tation included. With Terminal 920C Add $900.00 SYSTEM + I (1MB+) SYS+SS Computer System with 8" Single Sided Drives (801 R) without Terminal A&T (6 slot) $3595.00 A&T (8 slot) $3695.00 A&T (12 slot) $3795.00 SYSTEM + II (2MB+) SYS+DS Computer System with 8" Dual-Sided Drives (Qume DT-8) without Terminal A&T (6 slot) $4495.00 A&T (8 Slot) $4595.00 A&T (12 slot) $4695.00 MINI-SYSTEM + I (V2MB+) Computer System with 5V4" Single Sided Drives (uses B-51 Disk Drives) No Terminal A&T (6 slot) $2495.00 A&T (8 slot) $2595.00 A&T (12 slot). $2695.00 w MINI-SYSTEM + II (1MB+) Computer System with 5'A" Double Sided Drives (uses B-52 Disk Drives) No Terminal A&T (6 slot) $2795.00 A&T (8 slot) $2895.00 A&T (1 2 slot) $2995.00 DISK DRIVE PRODUCTS V QT DISK PACKAGES DDC-88-1 Dbl Den Controller, A&T, two 8" dbl den drives (801 R) CP/M® 2.2,cabinet, power supply & cables SPECIAL $1495.00 DDC-88-2 Two 801 R disk drives with cabinet, power supply, fan & cables $1200.00 DDC-88-22 Two DT-8 Qume drives with cabinet, power supply, fan & cables $1600.00 DDC-88-3 Cabinet with power supply, fans & cables $ 275.00 DDC-88-4 Cabinet only $ 75.00 DISK DRIVES 8" Shugart 801R Sgl/Sided Dbl/Den $ 450.00 Qume Datatrak 8" Dbl/Slded Dbl/Den QME-8DS (851R) compatible $ 650.00 Pkg of two $1250.00 SVa" MPI-B51 MPI B-51 $ 235.00 Sgl Sided Sgl/Dbl Den MPI-B52 MPI B-52 $350.00 Sgl Sided, Dbl Den MPI-B91 MPI B-91 $ 375.00 Sgl Sided, Dbl Den. 77 tracks Shugart SA400 SHU-SA400 $ 250.00 Sgl Sided, Dbl/Den S-100 PRODUCTS Double Density - Cal Comp Sys 5%" or 8" disk controller with free CP/M 2.2 CCS-2422A A&T $374.95 Expando RAM II - SD Systems 4 MHz RAM board expandable from 16K to 256K SDS-RAM216K 16K kit $289.95 SDS-RAM216AT 16K A&T $339.95 SDS-RAM232K 32K kit $329.95 SDS-RAM232AT 32K A&T $379.95 ITHACA AUDIO REV 2.0 Z-80 BD Bare Board $35.00 each 10 for $300.00 SEALS ELECTRONICS 32K STATIC BD Uses TMS-4044 or 5257L $35.00 each SDS-RAM248K 48K kit $369.95 SDS-RAM248AT 48K A&T $419.95 SDS-RAM264K 64K kit $409.95 SDS-RAM264K 64K A&T $459.95 PROM-100 - SD Systems 2708, 2716. 2732, 2758 & 2516 EPROM programmer SDS-PROM-100K kit $220.00 SDS-PROM-100AT A&T $275.00 QT MEMORY EXPANSION KITS TRS-80 •APPLE* EX ID Y 4116 200 ns 8 for $32.00 2716 (5V-450 ns) $ 9.00 2716 (5 & 12V-450 ns) $ 9.00 2732 (5V) $40.00 2114L 300 ns 8 for $36.00 100 - $3.50 ea. PARTS MICROPROCESSORS Z80 (2MHz) . . . $10.95 Z80A (4MHz) . . $12.95 6502 $11.25 6800 $12.50 6802 $18.00 8035 $20.00 8080A $ 3.50 8085A $20.00 8086-4 $60.00 8088 $60.00 8748 $60.00 TMS 9900 JL $29.95 8080A SUPPORT 8212 $ 3.50 8214 $ 4.50 8216 $ 2.95 8224 $ 4.00 8228 $ 6.00 8238 $ 6.00 8243 $ 5.00 8251 $ 7.00 8253 $19.00 8253-5 $20.25 8255 $ 6.25 8257 $17.95 8257-5 $19.00 8259 $19.95 8275 $69.95 8279 $17.50 8279-5 $18.00 8295 $16.50 KEYBOARD CHIPS AV5-2376 $13.75 AY5-3600 $13.75 BAUD RATE GENERATORS MC14411 1.8432 XTAL $11.00 $ 4.95 s^z DISK CONTROLLER 1771B01 $24.95 B01 $37.95 EPROMS 1702A $ 4.95 2708 $ 6.25 2516 (5V) $ 9.00 2716 (5V) $ 9.00 2716 (5 & 12V) $ 9.00 2758 $19.95 2532 $40.00 2732 $40.00 USRT S2350 $ 7.95 MISCELLANEOUS OTHER COMPONENTS N8T20 $ 3.25 N8T26 $ 2.50 N8T97 $ 2.00 N8T98 $ 2.00 1488 $ 1.25 1489 $ 1.25 D3205 $ 3.00 D3242 $14.00 P3404 $ 6.75 TMS5501 $19.00 DM8131 $ 3.00 UARTS TR1602B $ 4.50 AY5-1013A $ 4.50 CHARACTER GENERATORS 2513 $10.95 UP CASE (5&12V) 2513 $10.95 LWR CASE (5&12V) 2513 $ 9.75 UP CASE (5V) 2513 $10.95 LWR CASE (5V) 6800 PRODUCTS 6802P $18.00 6821P $ 5.25 6B40P $18.25 6845P $22.00 6850P $ 4.80 6860P $11.55 6875P $ 7.40 SBC+2/4 SINGLE BOARD COMPUTER Features: 1K RAM (which can be located at any 1K boundary) plus one each Parallel and Serial I/O parts on board • Power on jump to on-board EPROM (2708 or 2716) • EPROM addressable on any 1 K or 2K boundary • Full 64K use of RAM allowed in shadow mode • Programmable Baud rate selection, 110-9600 • 2 or 4MHz switch selectable • DMA capability allows MWRT signal generation on CPU board or elsewhere in system under DMA logic or front panel control • Two program- mable timers available for use by programs run with the SBC+2/4 (timer output and controls available at parallel I/O connector; parallel input and output ports available for use on CPU board). Bare Board $ 60.00 Kit $190.00 ^A&T $295.00^ V! Z+80 CPU Features: Power on jump to on-board EPROM (2708, 2716 or 2732) • EPROM addressed on any 1K or 2K boundary: also shadow mode allows full 64K use of RAM • On-board USART for Synchronous or Asynchronous RS-232 Operation (Serial I/O port) • Programmable Baud rate selection, 1 10-9600 • Switch select- able 2 or 4 MHz • MWRITE signal generated if used without front panel • Front panel com- patible. Bare Board $ 50.00 Kit $150.00 A&T $210.00 RAM+16 Features: S-100, 16K x 8 bit static RAM • 2 or4 . MHz • Uses 2114 1K x 4 static RAM chip • 4K step addressable • 1K increment memory protection, from bottom board address up or top down • Deactivates up to six 1K board segments to create "holes" for other devices • DIP switch selectable wait states • Phantom line DIP switch • Eight bank select lines expandable to 'h million byte system • Data, address and control lines all input buffered • Ignores I/O commands at board address. Bare Board $ 35.00 4Mhz Kit $190.00 4Mhz A&T $225.00 RAM* 65 •S-100, 16K x 8 bit static RAM «2 or 4MHz • Uses 21 14L(300NS) CHIP 'Addressable in 4K steps 'Memory protection in 1K increments, from bottom board address up or top down • May deactivate up to six 1 K segments of board to create "holes" for other devices • DIP switch selectable wait states • Phantom line DIP switch 'Features bank selection by I/O instruction using any one of 256 DIP switch- selectable codes— allows up to 256 software- controlled memory banks. Bare Board $ 35.00 4MHz Kit $210.00 ^4MHz A&T $250.00, \ f\ COMPUTER f«J SYSTEMS ^flU I INC. I 15620 South IngJewood Avenue I l.awndale. California 90260 J (21.1) 970-0952 QT PRODUCTS EXPANDABLE* REV II DYNAMIC MEMORY BOARD Features: Runs at 4MHz • 3242 refresh con- troller with delay line • Four layer PC board insures quiet operation • Supports 16K, 32K, 48K or 64K of memory • 24 IEEE-specified address lines • Optional M1 wait state allows error free operation with faster processors • Optional Phantom disable • Uses Z-80 or on- board refresh signal • Bank on/off signal selected by industry standard I/O port 40 (Hex) • Convenient DIP switch selection of data bus bits determines bank in use • 3 watts low power consumption • Convenient LED indication of bank in use. Definitely works with Cromemco and North Star Bare Board $ 75.00 ^ KIT No RAM .... $230.00 16K $280.00 32K $360.00 48K $480.00 64K $525.00 A&T 16K $350.00 32K $450.00 48K $575.00 64K $675.00 J CLOCK/CALENDAR* FOR APPLE II, S-100 OR TRS-80 Features: Date/Month/Year • Day of week • 24 hour time or 12 hour (a.m. /p.m.) select- able • Leap year (perpetual calendar) • 4 interval interrupt timer: 1024Hz (approx. 1 millisec), 1 sec, 1 min., 1 hr. • On-board bat- tery backup • Simple time and date setting • Simple software interface • Time advance protection while reading. Battery Included S-100 or Apple TRS-80 A&T $150.00 A&T Only . . . $150.00 Kit $100.00 Bare Bd $ 60.00 WATCH FOR THE FOLLOWING NEW BDS: 4 Port Serial Bd (APR) E-PROM Programmer (MAY) Floppy Disk Controller (JUN) Hard Disk Controller (JUN) Color Video Bd (AUG) INDUSTRIAL GRADE I/O BD Has two serial Sync/Async ports (RS-232, current loop or TTL) with individual Xtal controlled programmable baudrate genera- tors • Four 8-bit Parallel ports; one latched input port and other three can be programmed in combinations of input, output or bidirec- tional • Also, has three 16-bit Programmable Timers and an 8-level Programmable Interrupt Controller w/Auto restart (8080 / Z80) • Other features include; on-board clock divisor for timers, completely socketed, wire wrap posts for easy port configuration plus more. Bare Board $ 70.00 Kit $200.00 A&T $375.00 PLACE ORDERS TOLL FREE 1-800-421-5150 (CONTINENTAL U.S. ONLY) fEXCEPT CALIFORNIA) Apple is a trademark of Apple Computer, Inc. CP/M and MP/W are trademarks of Digital Research. TRS-80 is a trademark of Radio Shack. Circle 355 on inquiry card. SILENCE+ MOTHERBOARDS These motherboards are among the quietest on the market. A unique grounding matrix — with each line completely surrounded by ground shielding — eliminates need for ter- mination and gives high crosstalk rejection • They're customer-proven, without crosstalk sometimes operating at 14MHz • A LED power indicator helps eliminate zapped circuits • IEEE S-1 00 std. compatible, available with 6, 8, 12, 18 or 22 slots* (The 22 slot board fits Imsai chassis and has slot for front panel.) V 6 Slot Bare Board . . $ 25.00 Kit $ 40.00 A&T $ 50.00 8 Slot Bare Board . . $ 27.00 Kit $ 55.00 A&T $ 70.00 12 Slot Bare Board . . $ 30.00 Kit $ 70.00 A&T $ 90.00 18 Slot Bare Board . . $ 50.00 Kit $100.00 A&T $140.00, QT MAINFRAMES MF+ 5V<" Disk Mainframe with 25A Pwr Sup MF+MD12 (12 slot M/B) $500.00 MF+MD8 (8 slot M/B) $475.00 MF+MD6 (6 slot M/B) $450.00 MF+MD w/o M/B $400.00 Q.T. Mainframe MF+12 (12 slot M/B) $450.00 MF+18 (18 slot M/B) $500.00 MF+22 (22 slot M/B) $600.00 y MAINFRAME+ DISK DRIVE V Includes cabinet, 25 amp power supply, IEEE S-100 compat- ible 6, 8 or 12 slot motherboard and dual 8" disk drive with disk drive power supply. MF+DD6 $625.00 MF+DD8 $650.00 MF+DD12 $675.00 DDC-8 SINGLE 8" DISK CABINET Accepts one 8" disk drive (Shugart, Remex, PerSci, Siemens, etc.) • Fan cooled, with data cable and AC line filter to eliminate EMI • Operates from 100-1 25 VAC/200-250VAC at 50-60HZ • Disk drive NOT included. DDC+8 $195.00 TERMS OF SALE: Cash, checks, money orders, credit cards accepted. Also C.O.D. orders under $100.00. Minimum order S10.00. California resi- dents add 6% sales tax. Minimum shipping and handling charge S3. 00 Prices subject to change without notice. International sales in American dollars only. ^^^^_, . VIS* ] BITS & PIECES TRS-80/APPLE MEMORY EXPANSION KITS ^ 4116's RAMS 8for*29 00 % ADD S3.00 FOR PROGRAMMING JUMPERS FOR TRS-80 KEYBOARD 4116's 100 pes & UP $3.00 each 1000 pes & UP $2.75 each 2114-3L | 4096 BIT (1024x4) 300ns | LOW POWER STATIC RAM 8/ s 30 00 100 + s 3 00 5257-3L (TMS 4044) 4096x1 300ns LOW POWER STATIC RAM 8/ s 50 00 100 pes. + s 4 75 2732 2716 450ns 5 Volt only 16 KEPR0M s 11 95 each or 8/ s 68 00 2708 450ns 8K EPR0M s 8 50 each or 8/ s 54 00 $ 25.00 450ns 5 Volt only &/$1gQQQ 32 K EPR0M 8x4K B1232 and "D" SUB-MINIATURE ffi^CONNECTORS f y.v.v.-.v.y.-^ — I FEMALE — 1 — c aim llOOIJBUUUBnBIJH = Plug, Male Type - S | PART NO. : Socket, Female Type - C = Cover, Hood CND-0E9P CN0-DE9S CN0-DE9C CN0-DA15P CND-DA15S CND-DA15C CND-DB25P CND-OB25S CND-DBS1212 CND-P25H CND-DB51226 CND-DC37P CND-DC37S CND-DC37C CND-DD50P I CND-DD50S CND-DD50C CND-D20418 CND-RS2328F CND-5730360 DESCRIPTION 9 PIN MALE 9 PIN FEMALE 9 PIN COVER 15 PIN MALE 15 PIN FEMALE 15 PIN COVER 25 PIN MALE 25 PIN FEMALE 1 PC. GREY H000 2 PC. GREY H000 2 PC. BLACK HOOD 37 PIN MALE 37 PIN FEMALE 37 PIN COVER 50 PIN MALE 50 PIN FEMALE 50 PIN COVER HARDWARE SET 2 PR RS232, DB25P, EIA CLASS 1 CABLE 8 CON. 8 FT. CENT. 700 SERIES PRINTER CONNECTOR 1-9 $ 2.10 $ 2.70 $ 1.50 $ 2.75 $ 3.95 % 1.50 i 3.50 i 4.60 1.60 1.50 1.90 5.80 8.70 1.80 $ 8.75 $11.65 S 2.00 S 1.00 S19.95 S 9.00 PRICE 10-24 S 1.90 S 2.40 S 1.25 S 2.45 $ 3.60 S 1.30 $ 3.25 % 4.35 1.45 1.25 1.65 5.10 7.70 1.55 7.75 $10.25 i 1.80 S .80 $17.95 $ 7.50 25-99 $ 1.70 $ 2.10 $ 1.10 $ 2.15 $ 3.20 $ 1.10 $ 3.00 $ 4.20 $ 1.30 $ 1.10 $ 1.45 $ 4.45 $ 6.70 $ 1.30 $ 6.70 $ 6.90 $ 1.60 $ .70 $15.95 $ 6.00 21 pairs of nylon guides furnished for snap-in mounting on .25" multiples wi. VCT-CCK10O $ 49 80 P 1 ^ wibs. RACH MOUNTABLE CAGE Especially designed to accommodate S100 size Plugboards, Motorola Exorcisor,™ and Micromodule™ Plugboards. Cage has .081" thick anodized aluminum side walls. Will accommodate Plugboards 4.0" to 8.5" long and 10.0" to 1 1 .5" wide by 1/16" thick. Cages assemble quickly. CENTRONICS® 737-1 LETTER QUALITY DOT MATRIX PRINTER LIST $995.00 SALE $725.00 CEN737 fc3.Shugart SA801 R SALE SHU-SA8I 2 OR MORE $ 395 $41 00 00 ea. version 2.2 LIST $400.00 SALE California Computer Systems CCS2422A FLOPPY DISK CONTROLLER „ WITH CP/M VERSION 2.2 $375.00 IEEE S-100 COMPATIBLE SINGLE/DOUBLE DENSITY 5V4'78" DISK DRIVES SINGLE/DOUBLE HEADED ASSEMBLED & TESTED CCS-2810 Z80 CPU 2/4 MHZ CPU W/Serial I/O List Price SALE CCS-2810 A&T $300.00 $275.00 V s^L S-100 MOTHERBOARDS GBT-153U GBT-153A GBT-154U GBT-154A GBT-155U GBT-155A UNKIT 6 SLOT A & T 6 SLOT UNKIT 12 SLOT A & T 12 SLOT UNKIT 20 SLOT A & T 20 SLOT LIST PRICE $129.00 $169.00 $214.00 OUR PRICE $ 89.00 $119.00 $129.00 $149.00 $174.00 $189.00 MODEM SALE $129.00 THE STAR MODEM from LIVERMOR FEATURE FITS GTE HANDSETS! 2 YEAR WARRANTY EXCLUSIVE ACOUSTIC CHAMBERS The exclusive triple seal of Livermore's new flat mounted cups locks the handset into the acoustic chamber yielding superior acoustic isolation and mechanical cushioning. Designed to adapt to most common handsets used throughout the world, the STAR offers the utrqost in flex- ibility and transmission reliability. the utmost in tie: Specifications: • Data Rate: to 300 baud • Compatibility: Bell 103 and 113: CCITT • Frequency Stability: ±0.3 percent. Crystal controlled • Receiver Sensitivity: -50 dBm ON, -53 dBm OFF • Modulation: Frequency shift keyed (FSK) • Carrier Detect Delay: 1.2 seconds ON; 120 msec OFF ■ EIA Terminal Interface: Compatible with RS 232 specifications • Teletype Interface: 20 milliampere current loop • Optional Interfaces: IEEE 488; TTL; TTY 43 • International (CCITT) frequencies available • Switches: Originate/Off/Answer; Full Duplex/Test/Half Duplex • Indicators: Transmit Data, Receive Data, Carrier Ready, Test • Power: Supplied by 24 VAC/150 MA UL/CSA listed wall- mount transformer. Input 115 VAC, 2.5 waits. (A 220 VAC, 50 Hz adaptor is available upon request.) • Dimensions: 10" x 4" x 2" • Weight: 1.74 lbs. (3 lbs. shipping weight including AC adaptor.) • Warranty: Two years on parts and labor, excluding the AC adaptor which carries the manufacturer's warranty List SALE Part No. Description Price PRICE LIV-STAR RS232, TTL Modem $199.00 $129.00 LIV-STAR2UM RS232. 20MA Current Loop S199.00 S129.00 LIV-STAR-V21 CCITT European Standard $229.00 $209.00 LIV-IEEE IEEE 488 Standard $395.00 $249.00 LIV-IEEE-V21 IEEE 488, CCITT Standard VS465. 00 $388.00 CABLES Part No. Description CND-RS2328FRS232 8Cond8~ LIV-I2I IEEE to IEEE 2 Meter , , LIW-I2PET IEEE to Pet 2 Meter . tandard V $465.00 $388.00 ■ ES jd 99 -^Vl^^. Price ^M . ■ ~ $19.95 ^J 1 S59.95 9M $59.95 ^^ PROTECT YOUR INVESTMENT PROTECT YOUR DATA WITH ISDBflR GOF-IBAR46 LIST PRICE SALE PRICE s 79 95 53995 GOLD S-100 CONNECTORS PRIORITY ONE distributes the Tl S-100 Card Edge Connectors at tremendous volume for prices others only wish they could duplicate. JTfrn. SOLDER TAIL PRICE PartNo. V^Ol-9 10-24 25-99 100-249 TI-S100 STG^* 3,20 2.90 2.50 2.20 WIRE WRAP PRICE Part No. 1-9 10-24 25-99 100-249 TI-S100WWG 4.00 3.75 3.50 3.25 PRIORITY ONE ELECTRONICS 16723 B ROSCOE BLVD. • SEPULVEDA, CA. 91343 Terms: Visa, MC, BAC, Check, Money Order, U.S. Funds Only. CA residents add 6% sales tax. Minimum order $15.00 Prepaid U.S. orders less than $75.00 include 5% shipping and handling. MINIMUM $2.50. Excess refunded. Just in case ... please include your phone no. Prices subject to change without notice. We will do our best to maintain prices thru April, 1981'. (213) 894-8171 •SOCKET and CONNECTOR prices based on GOLD, not exceeding S.700 per oz. 'Sale Prices are for prepaid orders only. Credit card orders will be charged appropriate Ireight ORDER TOLL FREE 1-800-423-5633 ORDER TOLL FREE 1-800-423-5633 S-100 HEADQUARTERS THE DUAL PROCESSOR BOARD IS HERE! GBT161 8085 CPU BOARD GBT1612 8085/8088 CPU BOARD • 8088 & 8085A CPU • S-100 IEEE COMPATIBLE ■ SWITCHABLE CPU'S • 5 MHZ OR 2 MHZ SWITCHABLE • POWER ON JUMP TO ANY 256 BYTE BOUNDARY • POWER ON JUMP CAN BE DISABLED • CPU CAN JUMP ON POWER ON ONLY OR POWER ON AND RESET. • 24 BIT EXTENDED ADDRESSING • IMSAI FRONT PANEL COMPATIBLE • AVAILABLE WITH 8085A ONLY BOARD WITH 8085 ONLY List Price Our Price CBT161A Assembled & Tested $325.00 S305.00 BOARD WITH 8085 & 8088 GBT1612A Assembled & Tested $425.00 S399.00 ENHANCED Z80 S-100 CPU BOARD GBT160 Z80 CPU • 4-6 MHz Z80 CPU • IEEE S-100 Bus Compatible • On Board Prom Sockets For Up To 8K Prom • Power On Jump Start To Any 256Byte Boundary • On Board Memory Manager For Direct Addressing For Up To 16M-Bytes • Fully Maskable Vectored interrupts • Wait State Generation For All Machine Cycles ■ Bypassing Of All Supply Line To Suppress Transients • All ICs Are Socketed List Price Our Price (225.00 S295.00 $280.00 G8T160U Unkit GBT160A Assembled & Tested SPECTRUM S-100 COLOR GRAPHICS BOARD • Uses the MC6847 LSI IC • Uses 1372 color encoded/generator • Alphanumeric/graphics in 8 colors • Ultra dense 256 x 192 full graphics • 8K bytes, on-board low power RAM • One full duplex parallel I/O port with attention, enable & strobe bits with power for running joysticks, keyboards, etc. • A parallel port for graphics mode control | • Board may be used as a 4MHz RAM for program storage LIST PRICE QUA PRICE GBT144U UNKIT GBTI44A A&T S399.00 GBT2D SUBL0GIC UNIVERSAL GRAPHICS INTERPRETER SOFTWARE $299.00 $349.00 $35.00 INTERFACER I Our I/O board gives. you inparalleled flexibility and operating convenience. We include such features as: • 2 independently addressable serial ports (dip switch selec- table addresses) • Real LSI Hardware UARTs for minimum CPU housekeeping • RS232C. current loop (20mA). & TTL signals on both ports • Precision, crystal-controlled Baud rates up to 19.1 KBaud (Individually dip switch selectable) • Transmit & receive interrupts on both channels, jumperable to any vectored interrupt line • Industry standard RS232 level converters with five RS232 handshaking lines per port • Optically isolated current loop with provisions for both on- board & off-board current sources • UART parameters, interrupt enables. & RS232 handshaking lines are software programmable with power-on hardware default to customer specified hard-wired settings for maxi- mum flexibility • Port connectors mate directly to ribbon cable & DB25 con- nectors in standard pinouts • RS232 lines will conform to either master or slave configurations • Board gives full feature operation with both 2 & 4 MHz systems • Low power consumption: *8V @450mA: • 16V @ 150mA: -16V f3>70mA max. • No soltware initialization required for board operation, although board parameters may be altered by software LIST PRICE OUR PRICE GBT133U UNKIT S199.00 GBT133A A&T $249.00 $219.00 INTERFACER II 3PTS 1 independently addressable serial port RS232C: 20mA current loop, & TTL signals Precision crystal controlled Baud rate generator Up to 19.2K Baud Transmit and receive interrupts, jumperable to and vectored interrupt line Five RS232 handshaking lines Optically isolated current loop 3 parallel I/O Utilizes LSTTL octal latches for latched I/O data with 24mA drive current Enable & strobe bits on each port (each with selectable polarity) < Interrupts for each input port ■ Separate 25 pin connector with power lor each channel and a status port for interrupt mask & port status LIST PRICE OUR PRICE ECONOROM 2708 Has provisions for wait states for 4MHz operations. Con- figured as four 4K blocks— each independently addressa- ble and disababie. Power-on jump. Does NOT include 2708s. Includes all support chips, sockets, regulators. heat sinks, etc. Sold in UNKIT form only. Shipping Weight 2 lbs. GBT125U Unkit $85.00 *NEW!* DISK 1 HIGH PERFORMANCE FLOPPY DISK CONTROLLER Finally, a floppy disk controller worthy of bearing the CompuPro name is now available for integration into your S-100 system. The DISK 1 floppy controller incor- porates numerous features that were previously unavailable on a DMA floppy disk controller board. DISK fully complies with the IEEE 696 bus standard, IN- CLUDING DMA ARBITRATION! Third generation INTEL 8272/NEC 765A LSI floppy disk controller. High speed cycle stealing DMA interface for pro- cessor independent data transfer between system memory and flexible disk. Handles up to four 8 or 5.25 inch floppy disk drives. Single or double density / single or double sided capability. Supports IBM 3740 soft sectored formats. 24 bit DMA addressing with data transfer across 64K boundaries for data transfer throughout the 16Mbyte memory map. I/O mapped interface allows contiguous system memory. (DISK 1 occupies no memory space) On board Phantom boot EPROM for automatic startup. On board serial port for initial system startup. Board compatible with MP/M, OASIS, CP/M-80 and CP/M-86. Board supplied with BIOS for CP/M-80 CP/M-80 and CP/M-86 available for DISK 1. CPU speed independent data transfer for operation up to 10MhZ. Fully arbitrated DMA interface as per IEEE 696 for allowing multiple DMA devices without conflict. May be interrupt driven for multi-user environments. Up to 600K bytes per side (8 inch drive) for an on-line total of up to 4.8M bytes (4 drives - double sided -double density) LIST PRICE OUR PRICE GBT-171BA Disk 1 A&T $495.00 $445.00 SYSTEM SUPPORT 1 MULTIFUNCTION BOARD This multi-purpose S-100 board provides your com- puter with the most needed system support functions -at less cost than buying numerous single function boards. Includes sockets for 4K of extended address EPROM or RAM (2716 pinout), 1 socket with battery backup; crystal controlled month/day/year/time clock with BCD outputs; optional high speed math processor (951 1 or 9512); full RS-232 serial port; three 16 bit interval timers (cascade or use independently); two interrupt controllers service 15 levels of interrupts; power fail in- dicator with provision to switch CMOS memory to bat- tery backup; and comprehensive owner's manual with numerous software examples. Conforms fully to all IEEE 696/S-100 standards. Want to make your S-100 system more versatile? System Support 1 is the answer. LIST PRICE OUR PRICE GBT-162U unKit 5295.00 GBT-162A A&T $395.00 $360.00 GBT-9512 Match Clip $195.00 Static S-100 Memory PRIORITY ONE ELECTRONICS (2i 3i 16723 B ROSCOE BLVD. • SEPULVEDA, CA. 91343 ' 32K ECONORAMXX 32K Bank Select. IEEE S-100 compatible. Features one 32K block that can be addressed on 4K boundaries. Com- patible with the IEEE proposed standard of 24 address lines as well as all currently used bank select configura- tions. Any or all of the eight 4K byte blocks may be disabled to create as many windows in memory to avoid any system memory conflicts. List Price Our Price GBT164A16 16K RAM A & T $399.00 $329.00 GBT164A24 24K RAM A&T $539.00 $455.00 GBT164A32 32K RAM A&T $699.00 $569.00 89 4-fti CA residents add 6% sales tax, ®lf1 Terms: Visa, MC. BAC. Check, Money Order, U.S. Funds Only. Minimum order $15.00 Prepaid U.S. orders less than $75.00 include 5% shipping and handling. MINIMUM $2.50. Excess refunded. Just in case ... please include your phone no. Prices subject to change without notice. We will do our best to maintain prices thru APRIL, 1981 'SOCKET and CONNECTOR prices based on GOLD, not exceeding $700 per oz. •Sale Prices are for prepaid orders only. Credit card orders will be charged appropriate freight ORDER TOLL FREE 1-800-423-5633 ORDER TOLL FREE 1-800-423-5633 Circle 356 on inquiry card. IMAGINE THE STOI AN 8 INCH FLOPPY 315K BYTES PER SIDE ON 5 1/4" OF COURSEI Micropolis. the worlds largest manufacturer of high density 5 1/4" disk drives, has been doing it for years. Arid reliably at that. An ordinary 5 1/4" floppy provides just 35/tracks per side and stores only 70K bytes; This is not nearly enough for anything useful, so instead, Micropolis uses 77 tracks per side. Each track is then formatted with 16 sectors (hard) at 256 bytes per sector yielding an impressive 315K bytes per side. Micropolis drives have a larger capacity than many 8" disk drives, though it only occupies the "space of a 5 1/4" floppy The 315K byte capacity is roughly 4 times the capacity of a standard 5 1/4" drive. This is what we call QUAD DENSITY. To achieve the high density capability, you may think Mcropolis had to sacrifice speed or reliability. NOT SO! The track to track access firhe is only 30ms with a high speed data transfer rate of 250,000 bits per second, By creating this high density format, Micropolis is able to keep your initial subsystem costs to a minimum. Your cost is less than $.002 per byte. Thats a BIG VALUE in a small package. MICROPOLIS disk subsystems are expandable to keep up with your ever increasing needs. Up to four drives/heads may be daisy-chained on one S-lOO controller board. With all four drives/heads in operation, you have access to over 1.2 MEGABYTES of on-line storage. WITH MICROPOLIS, complete means COMPLETE, Each sub- system comes complete with controller interface, cable, and software. The software Includes the MDOS operating system extended basic, assembler and editor. Everything you need to get "On Line" In one complete package. MICROPOLIS provides total Integration which means they control everything from beginning to end. The result is a better drive for you, backed by a full 120 day factory guarantee. Anyone can cut price. by cutting out capacity or valuable features. But there's no long term advantage in it. Not for the user. Or the builder. MICROPOLIS takes a better approach, even though it's harder, using advanced design to provide more capability while also lowering cost, For example, most 5 1/4-inch floppy disks cut costs by using a cheap, less accurate plastic cam or cam follower to posi- tion the read/write head. Most 8-inch floppy disks use a better approach, with a rolled steel lead screw for this function. We go them one better and use an all-steel system, with a precision-ground steel lead screw and" steel follower. It costs more but gives us greater storage capacity with lower cost per thousand bytes. Not so incidentally, our steel construction (compared to plastic) significantly increases reliability, too. There's even a built-in File Protect feature that prevents ac- cidental loss of valuable data. (A file protected diskette can- not be written on.) Heat can cause numerous read and write errors that can become hazardous to your data. The major heat producing power supply components are mounted to a large heat sink, external to the cabinet, by the power switch and fuse (located at the rear of the cabinet), This design is to assure that the drive components are kept as cool as possible to assure reliable data recovery. MICROPOLIS has a reputation for getting along with most everybody. Compatabllity is not a problem with MICROPOLIS. Their disk drives and/or subsystems can be easily integrated into systems such as Polymorphic, Cromemco, CCS, Ithica Intersystems, Godbout, Northstar, Jade Big Z, QT SBC 2/4, and many others. Many OEM manufac- turers rely on MICROPOLIS to get the job done efficiently. Companies like Commodore, Exldy, Harris, and Vector Graphics to name just a few. Years from now, you can look back with a secure feeling knowing you made the best choice. MICROPOLIS. HGE CAPACITY OF IN 5 1/4" FORMAT THIS /VtKtf*OT5C^»JKi NOT THIS minimi Because of our incredible purchasing power, PRIORITY ONE ELECTRONICS is able to buy MICROPOLIS disk drives by the thousands and receive special pricing. That special pricing we receive is passed on to you in the form ot tremendously discounted prices. Now all thai remains is for you to take ad- vantage of this truly incredible buy. MODEL MCP-1053-4 MCP-1053-2 MCP-1043-2 MCP-1041-2 MCP-1042-1 MCP-1041-1 DESCRIPTION S-100 SUBSYSTEMS LIST 1.2 MB 2 HEAD DUAL 630 KB DUAL 315 KB SINGLE 315 KB SINGLE, NO PS 143 KB SINGLE 143 KB SINGLE, NO PS $2605.00 $1895.00 $1145.00 $1045.00 $795.00 $695.00 SALE PRICE $1395.00 $995.00 $695.00 $639.00 $625.00 $595.00 COMPLETE W/S-100 CONTROLLER, CABLES, MANUALS AND MICROPOLIS MDOS AND BASIC ADD-ON DRIVES MCP-1033-2 MCP-1023-2 MCP-1021-2 MCP-1022-1 MCP-1021-1 630 KB DUAL 315 KB SINGLE 315 KB SINGLE, NO PS 143 KB SINGLE 143 KB SINGLE, NO PS $1395.00 $645.00 $545.00 $545.00 $445.00 $895.00 $495.00 $475.00 $375.00 $360.00 REQUIRES ACCESSORY ADD-ON CABLES GOOD NEWS FOR TRS-80* OWNERS We now have a complete line of TRS-80* Model 1 compati- ble MICROPOLIS add on drives in matching colors. These drives simply plug into the expansion interface via a disc data cable. 197K BYTES PER SIDE FOR YOUR TRS-80*, that's easy! Just order a 77 track add on drive and the New DOS-80 operating system. Among the many features of New DOS-80, is its ability to control any mix of 35, 40, or 77 track drives on the same cable. TRS-80® DISK DRIVES MCP-1027-1 MCP-1037-1 MCP-1027-2 MCP-1037-2 APP 395M PR1-34CEEE-2 PR1-34CEEE-4 35 TRACK SINGLE 35 TRACK DUAL 77 TRACK SINGLE 77 TRACK DUAL $545.00 $1195.00 $645.00 $1395.00 ACCESSORIES NEW DOS/80 TRS-80® 35 thru 77 SUPPLIED TRACK OPERATING 35 TRACK SYSTEM $149.00 Two Drive Data Cable Four Drive Data Cable GOOD THRU APRIL 1981 $279.00 $695.00 $439.00 $795.00 ON 77 TRACK $159.00 $29.95 $39.95 THIS COULD BE THE START OF SOMETHING SMALL. SEE US AT THE WEST COAST COMPUTER FAIR AND PICK UP YOUR DRIVES. 1-800-423-5633 PRIORITY ONE ELECTRONICS 16723 B ROSCOE BLVD. • SEPULVEDA, CA. 91343 (213)894-8171 Terms: Visa, MC, BAC, Check, Money Order, U.S. Funds Only. CA residents add 6% sales tax, Minimum order $15.00 Prepaid U.S. orders less than $75.00 include 5% shipping and handling. MINIMUM $2.50. Excess refunded. Just in case ... please include your phone no. Prices subject to change without notice. We will do our best to maintain prices thru April 1981. 'SOCKET and CONNECTOR prices based on GOLD, not exceeding $700 per oz. *Sale Prices are for prepaid orders only. Credit card orders will be charged appropriate freight •TRS-80 is a registered trademark of Tandy Corp. Circle 357 on Inquiry card. Best Prices and Delivery! i SUPERBRAIN by Intertec Self-contained computer with duat disks and two RS232C ports. Complete with CP'M' 2.2 and BASIC. ...... 32K Double Density, List $2995 . YtUOU 64K Double Density, List $3345 $2883 64K Upgraded to Quad Density w/ Special MiniMicroMart Warranty SPECIAL $3395 VIDEO TERMINALS /VflrV EMULATOR (Intertec), List $895$ 749 NEW INTERTUBE IHList $895 . . . ONLY $ 749 SOROC 120, List $995 SPECIAL $ 729 1Q140, List $1495 SPECIAL $1149 PERKIN-ELMER 550, List $997 $ 799 with anti-glare screen, $1027 $ 829 HAZELTINE 1410, List $900 $ 749 1420 $ 849 1500, List $1225 $ 879 1510, List $1395 $1089 1520, List $1650 $1389 LEAR SIEGLER ADM3A, Assembled . . $ 849 TELEVIDEO 912C, List $950 $ 789 920C. List $1030 $ 849 950C, List $1 1 95 NEWS1039 ANADEX DP-8000 $ 849 DP-9500, List $1650 $1399 DP-9501 . List $1650 $1399 PAPER TIGER IDS-445, List $995 $ 695 w/graphics op., incl. buffer, $1195 .. $ 789 PAPER TIGER IDS-460, List 1149 PAPER TIGER IDS-460G List 1199 NEW IDS PAPERTIGER 460 . List 1295 SH49 NEW IDS PAPERTIGER 460G List $1394 $1199 NEC Spinwriters Call for Price TELETYPE 43 KSR $1087 CENTRONICS 730-1 parallel interface . . NEW LOW $ 649 737 parallel interface . SUPER VALUE $ 829 779 w/Tractor, List $1350 $1049 703 w/Tractor, VFU, List $2975 $1695 704 w/Tractor, VFU, List $2350 $1595 Tl 810 Basic, List $1895 $1695 810/serial & Centronics-style parallel interface. List $1940 $1735 810 w'full ASCII (U/LC), Vertical Forms Control, Compressed Print . . $1895 Tl 820 KSR, List $2165 $1895 Tl 745 w/full ASCII, List $1695 $1399 COMPRINT 912 w/parallel interface . . $ 559 912 w/serial interface, List $699 $ 589 AXIOM IMP I $ 699 MICROTEK, List $750 $ 675 OKIDATA Microline 80, List $949 $599 Tractor Feed Option $109 RS232 Serial Interface $ 99 NORTH STAR HORIZON" HORIZON 1 ASSEMBLED & TESTED 32K, Double Density, List $2695 .... $2279 32K, Quad Density, List $2995 $2539 HORIZON 2 ASSEMBLED & TESTED 32K, Double Density, List $3095 $2619 32K, Quad Density, List $3595 $3049 48K, Double Density, List $3590 $3039 48K, Quad Density, List $4090 $3469 64K, Double Density, List $3830 $3239 64K, Quad Density, List $4330 $3669 FLOPPY DISK SYSTEMS NORTH STAR MDS-A Assembled, List $899 . . MORROWTHINKERTOYS - Discus2D, List $1199 OUR PRICE $ 998* Discus 2D, dual-drive. List $1994 $1694* Discus 2 + 2, A&T, List $1549 $1319* Dual Discus 2 + 2, A&T, List $2748 . . . $2335* "Now includes CP/M" 2.2 Prom Programers SSMPB1 Kit List $125 $106 SSM PB1 A&T List $190 $161 SD Computer Prom 100 Kit $236 $201 SD Computer Prom 1 00A&T List $31 1 . . $264 FLOPPY DISK CONTROLLER BOARDS NORTH STAR, DD, Assembled, List $499 $399 MORROW Disk Jockey 1, A&T ($213) . $189 Disk Jockey 2D, A&T, List $479 $429 SD Versafloppy 1 , Kit, List $284 $239 Versaf loppy II, DD Kit, List $41 3 $349 Versafloppy II, DD, A&T, List $507 . . . $429 DELTA double density A&T ($385) $345 CONDUCTOR, double density A&T . . . $269 INTERSYSTEMS FDC-2, A&T, $495 . . . $439 MICROMATION Doubler, DD, A&T . . . $429 TARBELL Floppy Disk Interface Kit ... . $199 double density, A&T, List $495 $444 CPU BOARDS (assembled unless noteai NORTH STAR Z80A IZPB-A'AI, $299 $254 CROMEMCO 4 MHz (ZPU-W), List $395 $335 4 MHz (SCC-W), List $450 $382 INTERSYSTEMS (formerly Ithaca Audiol new Series II Z-80, 4 MHz. List $395 . . . $349 SSM CB1 8080 A&T List $252 $214 CBIAKit, List $183 $156 CB2 Z-80, A&T, List $344 $289 CB2 Kit, List $60 $221 DELTA Z-80, with I/O $289 SD SBC-1 00, List 41 3 $349 SBC-1 00 Kit, List $341 $289 SBC-200, List $471 $399 SBC-200 Kit, List $373 $317 MEMORY BOARDS specials 719 32K SD ExpandoRAM Kit CALL FOR PRICES ESCON CONVERSION FOR IBM SELECTRIC Complete w/ microprocessor controller and power supply. Factory built. User installs solenoid assembly or it can be done at Escon factory at nominal cost. Parallel (TRS-80, Sorcerer, etc.), $575 $514 RS232 Standard Serial, List $599 534 IEEh-488 (for PET), List $660 584 TRS-80 Cable 25 CALIFORNIA COMPUTER SYSTEMS Z80 CPU BOARDS List $299 $269 DISK CONTROLLER 2422 List $399 .... $359 16K Static, A&T, List $349.95 $259 32K STATIC List $71 $599 64K DYNAMIC BOARD List $699 $589 NORTH STAR 16K Dynamic RAM Board, A&T (RAM-16-A/A), List $499 $42( 32K A&T (RAM-32/A), List $739 $62C CROMEMCO 16KZ-W, List $495 $419 64KZ-W, List $1795 $1269 MEASUREMENT SYSTEMS & CONTROLS (Guaranteed performance, incl. labor/parts 1 yr DM6400 64K Board w/all 64K, $795 . . . $65' DM4800 with 48K, List $695 $65( DM3200 with 32K, List $595 $50! DMB6400 64K Board w'all 64K $85! DMB4800 with 48K $78! MORROW SuperRAM - all static, all A&T 16K, 4 MHz or 2 MHz, List $349 . $299 32K, 4 MHz, List $699 $629 16K Memory Master, List $399 $339 24K Memory Master, List $549 $465 INTERSYSTEMS (formerly Ithaca Audio) 8K Static 2 MHz, A&T, List $165 $149 8K Static 4 MHz, A&T, List $195 $176 16K Static 2 MHz, A&T, List $475 $427 16K Static 4 MHz, A&T, List $495 $445 64K Dynamic, List $995 $895 CALIFORNIA COMPUTER 16K Static, A&T, List $349.95 $259 I/O Mapped SD COMPUTER VDB-8024, kit, List $437 . 369 Assembled, List $556 $469 XITEX SCT-100K, Kit ONLY $169.95 SCT-100A Assembled $189.95 SSM VB2 I/O, Kit, List $199 $169 Assembled & Tested, List $269 $229 Memory Mapped SSM VB1C, 16x64, Kit, List $179 $ 152 Assembled & Tested, List $242 S206 SSM VB3, 80-Char.,4MHz,Kit.List$425- • $359 4 MHz, A&T, List $499 $424 INTERSYSTEMS, Ibxba, A&T, List $1bb $149 "Subject to change. NEW CROMEMCO 16FDC DOUBLE DENS 0ISK CONTROLLER List $595 OUR PRICE SHIPPING AND INSURANCE: Add $2.50 for boards, $6 for Selectnc Converter or Floppy Disk Drives, $7 50 for Floppy Disk Systems, $15 for Horizon. SHIPPED FREIGHT COLLECT SuperBram, Centronic and T.I. printers. Contact us for shipping information on other terminals and printers. Mjove prices reflect a 2% cash discount (order prepaid prior to shipment) Add 2% to prices for credit card orders, C.O.D.'s, etc. Prices are subject to change and offers subject to withdrawal without notice MiniMicroMart, Inc. 1618 James Street, Syracuse NY 13203 (315)422 4467 TWX 710-541-0431 If North Star or Cromemco offer it . . WE HAVE IT!! Immediate Deliver y at Discount Prices NORTH STAR Horizon 2 32K Double Density Assembled and Tested Ls Xl 5 y$2619 S3 ASSEMBLED HORIZON 1. DD $2279 32K. QD, List $2995 2539 HORIZON 2, 32K, DD $2619 32K. QD. List $3595 3049 48K, DD, List $3590 3039 48K, QD, List $4090 3469 64K, DD, List $3830 3239 64K, QD, List $4330 3669 NORTH STAR APPLICATIONS SOFTWARE (Exclusive lor use with North Star Disk Systems — specify Double or Quad Density) NORTHWORD, List $399 $339 MAILMANAGER, List $299 249 INFOMANAGER, List $499 419 GENERALLEDGER, List $999 799 ACCOUNTSRECEIVABLE, List $599 499 ACCOUNTSPAYABLE, List $599 499 NORTH STAR HARD DISK HD 18 18 megabytes, plugs into parallel port of North Star Horizon. Utilizes tried-and-proven 14" Century Data Marksman. List $4999. QUR pR|CE $41 gg NORTH STAR MDS-A - Double (or Quad) Density Disk System, Kit, List $799 . OUR PRICE $669 Assembled and Tested, List $899 SPECIAL $719 NORTH STAR MEMORY BOARDS 16K Dynamic RAM (RAM-16-A/A), Assembled. List $499 $420 32K IRAM-32/AI, Assembled, List $739 $620 INTRODUCTORY SPECIALS ON ... PREMIUM QUALITY BASF DISKS CERTIFIED FOR QUAD SYSTEMS 5V DOUBLE DENSITY DOUBLE SIDED usi$57.50 8" DOUBLE DENSITY DOUBLE SIDED ust$75.00 . Shipping $2 50 - Free Shipping In Multiple 01 Two Boi i (Box of ten) ., $38.95 . . $47.49 /MEW System 3 by CROMEMCO Now with Dual Double Sided Double Density over 2 megabytes of Storage) 64K of RAM List $7995 LIMITED TIME $6395 CROMEMCO SYSTEM 2 — Now double Density with Double Sided Drives, Quad Capacity mini floppy disc drives. List $4695 Only $3899 CROMEMCO Z-2H Ful 11 -megabyte Hard Disk system. Fast Z-80A 4 MHz processor, two floppy disk drives, 64K RAM memory, RS232 special interface, printer interface, and extensive software available. List $9995 our price $8489 NEW DOUBLE DENSITY CONTROLLER BOARD From Cromemco With built-in diagnostics — 16 FDC Controller List $595 OUR PRICE $505 Z-2 COMPUTER SYSTEM List $995 $845 SINGLE CARD COMPUTER - SCC-W 4 MHz. List $450 $382 NEW COLOR GRAPHICS INTERFACE - SDI List $595 OUR PRICE $505 CROMEMCO HOD — 1 1 /22-megabyte Hard Disk for use with existing systems. DMA controller. Transfer rate of 5.6 megabytes/second. H00-11. List $6995 OUR PRICE ONLY $5939 HDO-22. List $11,995 $10,189 SHIPPING AND INSURANCE: Add $15 or Horizons, $2.50 fo Advertised prices are for prepaid orders. Credit card and CO subject to withdrawal without notice. r Boards and Software. Hard Disk Systems and Cromemco systems shipped freight collect. D. 2% higher. Deposit may be required on C.O.D. All prices subject to change and offers WRITE FOR FREE CATALOG - MiniMicroMart, Inc. 1618 James Street, Syracuse, NY 13203 (315)422-4467 twx 710-541-0431 master charge Circle 358 on Inquiry card. Computers, Disk System YfHiza I data I systems Z89-FA List $2895 OUR PRICE $2395 Z-89GA List $2595 $2149 A-87 Two Drive Minifloppy System List $1 195 $989 Z-47DA $3695 8" Two Megabyte List $3695 $3059 INTERSYSTEMS formerly ITHACA AUDIO The new Series II CPU Board features a 4 MHz Z-80A CPU and a full-feature front panel. 20- slot actively terminated motherboard, with 25 amp power supply (50/60 Hz operation, incl. 68cfmfanl. DPS-1 , List $1795 $1495 COMPLETE SYSTEM with InterSystem 64K RAM, I/O Board w/priority interrupt and double density disk controller board. Full 1-year warranty, List $3595 $2995 NEW! CR0MEMC0 SYSTEM ZERO List $995 OUR PRICE $849 NEW! CROMEMCO SYSTEM ZERO/D A complete 64K Computer with Double Density Disk Controller List $2995 OUR PRICES2545 Companion Disk drive for above — Quad Density — Total of 780 Kilobytes of storage on the two drives List $1295 OUR PRICE $1099 Only $3644 for a complete 64K Disk System SUPERBRAIN BvlNTERTEC 64K Double or Quad Density units available. Uses two Z-80 CPU's. Commercial-type terminal with 12" monitor. Dual double density minifloppies. Over 350 kilobytes of storage (twice that with quad density drives). Two serial RS232 ports, I/O ports standard. Expandable with optional S-100 S-100 interface. Comes with CP/MTM 2.2 operating sys- tem. MiniMicroMart can supply a wide range of CP/M development and application software. w/64K Double Density, List $3495 . . $2869 W/64K Quad Density, List $3995 $3395 HEWLETT PACKARD HP-41CV HP-41 System I- $399. (The HP-41CV and HP82104A Card Reader) List $495. HP-41 System II— $679. (The HP-41CV andHP82104A Card Reader, HP82143A Printer/Plotter) List $ 840. HEWLETT-PACKARD HP-85A DeskTop Computer MORROW THINKER TOYS® DISCUS M26™ 26 megabytes of formatted storage List $4,995 $4,199 List $3250 $2749 THINKER TOYS® DISK SYSTEMS Now includes CP/M® 2.2 Discus 2D, List $1199 $1019 Discus 2D, dual-drive, List $1994 $1694 Discus 2 + 2, Assem., List $1549 $1319 Dual Discus 2 + 2, Assem., $2748 $2335 All Morrow systems now include CP/M' 2 2 MORROW Discus 2D's IN STOCK NEW! CR0MIX FROM CROMEMCO A New UNIX Like Disk Operating System, With true multi-user, multi-tasking capabilities List $295 OUR PRICE $249 NEW! DOUBLE DENSITY CONTROLLER BOARD FROM CROMEMCO With built-in diagnostics 16 FDC Controller, List $595 OUR PRICE $505 RADIO SHACK TRS-80™ 10% OFF!, Terminals and Printer Intertec EMULATOR Software compatible with a Soroc IQ-120, Hazeltine 1500, ADM-3A or DEC VT-52. Fea- tures block mode transmission and printer port; 12" anti-glare screen; 18-key numeric keypad; full cursor control. List $895 OUR PRICE $749 NEW INTERTUBE III List $995 ONLY $749 12" display, 24 x 80 format, 18-key numeric keypad, 128 upper/lower case ASCII charac- ters. Reverse video, blinking, complete cursor addressing and control. Special user-defined control function keys, protected and unpro- tected fields. Line insert/delete and character insert/delete editing, eleven special line draw- ing symbols. TELEVIDEO TVI-912C T ,'.y.;.i.i.!.i.!.!.!.i.lH Upper and lower case, 15 baud rates: 75 to 19,000 baud, dual intensity, 24 x 80 character display, 12 x 10 resolution. Numeric pad. Pro- grammable reversfole video, auxiliary port, self test mode, protect mode, block mode, tabbing, addressable cursor. Microprocessor controlled, programmable underline, line and character insert/delete. "C" version features typewriter-style keyboard. List $950 OUR PRICE $789 HAZ 1500 ONLY $879 PAPER TIGER 1410 w/numeric keypad, List $900 $749 1420 w/lower case and numeric pad 849 1510, List $1395 1089 1520, List $1650 1389 SOROC IQ-120 List $995 SPECIAL 729 IQ-140 List $1495 SPECIAL $1149 CENTRONICS PRINTERS NEW 730, parallel, friction, tractor . . . $679 NEW 737 parallel, friction, tractor $849 779-2 w/tractor (same as TRS-80 Line Printer I), List $1350 1049 702 120 cps, bi-direct., tractor, VFU .... 1995 703 185 cps, bi-direct., tractor, VFU .... 2395 704 RS232 serial version of 703, $2350 . . $1995 NEC SPINWRITER ™ Terminal/Keyboard as well as RO Printer Only models available. CALL FOR PRICES! IDS 455 Paper Tiger, List $995 $895 w/graphics option, incl. buffer, $1194 . . $989 TRS-80 cable 45 NEW IDS 460 QUALITY PRINTING AT MATRIX SPEED-LOGIC SEEKING PROPORTIONAL SPACING w/auto text justification NEW IDS PAPERTIGER 460List $1295 . $1099 NEW IDS PAPERTIGER 460G List $1394 $1149 TI-810 TI-810 Basic Unit, $1895 . ONLY $1595 TI-810 w/full ASCII (Lower case), vertical forms control, and compressed print . $1795 TI-745 Complete printing terminal with acoustic coupler, List $1695 .... $1399 RNFID6X DP9500/DP9501 PRINTCRS DP-9500. List $1650 $1349 DP-9501, List $1650 $1349 ANADEX 80-Col. Dot Matrix $849 OKI DATA Microline80 ONLY $599 Tractor Feed Option $109 Serial interface $ 99 AXIOM IMP I $699 COMPRINT 912 w/parallel interf $559 912 w/serial interface, List $699 $589 MICROTEK, List $750 $675 920C (with 1 1 function keys, 6 edit keys and Above prices reflect a 2% cash discount (order prepaid prior to shipment). Add 2% to prices for credit 2 transmission mode keys. List $1030 card orders, C.O.D.'s, etc. Prices are f.o.b. shipping point. Prices are subject to change and offers ONLY $849 subject to withdrawal without notice. WRITE FOR FREE CATALOG. MiniMicroMart, Inc. 1618 James Street, Syracuse NY 13203 (315) 422-4467 TWX 710 -541 -0431 Circle 359 on Inquiry card. Unclassified Ads UNCLASSIFIED POLICY: Readers who are soliciting or giving advice, or who have eguipment to buy, sell or swap should send in a clearly typed notice to that effect. To be considered for publication, an advertisement must be clearly noncommercial, typed double spaced on plain white paper, contain 75 -words or less, and include complete name and address information. These notices are free of charge and will be printed one time only on a space available basis. Notices can be accepted from individuals or bona fide computer users clubs only. We can engage in no correspondence on these and. your confirmation of placement is ap- pearance in an issue of BYTE. Please note that it may take three or four months for an ad to appear in the magazine. FOR SALE: Apple Pascal language system. Never used, still in original packing with factory warranty for $400. M Antonovich, Box 6020, Wyomissing PA 19610. FOR SALE: Moving, must sell; complete Texas In- struments 9900 minicomputer. Processor board with operating system in prom, 2 K cache programmable memory, 9900 processor, and I/O interface. Memory board with 32 K bytes of programmable memory and complete buffering. Cassette interface and 9600 bps digital cassette player/recorder. Complete system soft- ware: Assembler, Linking Loader, Text Editor, Super BASIC, and lots of games. All contained in a fan-cooled chassis. Total price for entire hardware/software com- puter system is $1800. Bernard H Penney, 31 Wheeler Dr, Peekskill NY 10566, (914)945-1044 day/(914) 528-1612 night. FOR SALE OR TRADE: Kenwood amateur radio equip- ment: TS520S transceiver, frequency readout, AT200 tuner, 6- and 2-meter transverters, and variable frequen- cy oscillator. All service manuals and cables included. Will sell or trade for Heath H-89 or H-8 computer system. Edward H Hill Sr, 3046 Stuart St, Indianapolis IN 46218, (317)545-8886. FOR SALE: PDP-11. DEC PDP-11/05 processor boards with 4 K core memory, 16 to 64 K programmable mem- ory, and parity controller. All working. Also, Tl Silent 743 (new) with full ASCII keyboard. Sell all, separately, or trade for line printer or what have you. Make offer. Jack Kreska, 1429 Warwick St, Garland TX 75042, (214) 495-2680. FOR SALE: Microcomputer magazine collections. BYTE 10/76 (#14) to 12/80 (51 issues) for $50. Kilobaud Microcomputing 1/77 (#1) to 12/80 (all 48 issues published) for $70. Interface Age 7/76 (#8) to 8/80 (48 issues plus several original SCCS journals) for $35. All plus book rate postage. John Cameron, POB 1517, Palo Alto CA 94301, (415)327-0341. HELP: I need any information at all about a Compucord 1210 digital cassette tape transport made by Compu- cord Inc of Waltham, Massachusetts. The company no longer exists, at least in Waltham. Any information regarding this device, the manufacturer, or any source of documentation is eagerly sought. I will be happy to pay for copying, or copy and return all material by return mail. Fred Goldberg, 29 Clearview Rd, E Brunswick NJ 08816, (201)257-8753. MUST SELL: One slightly used Cray-1— too big for my apartment. Hardware included: light-dimmer interface, toaster interface, one homebrew 64-bit parallel I/O port with Nixie-tube indicators, coat hangers, extra buffing powder for instruction buffers, one box of bootstraps. Software included: CAL assembler on thirteen cassette tapes in Kansas City format, Morse-code trainer, tic-tac- toe game, 8080 emulator. Price is negotiable. A Pri.fiil, POB 463, Peanutbutter NH 03458. FOR SALE: TI-59, PC-100A (in perfect working condi- tion), three modules (Master, Statistics, Mathematics and Utilities), eight specialty packettes (Engineering, Science, Securities, Marketing, etc), 20-roll paper for PC- 100A, and many finance utility programs. If brand new, you would pay $640. Now all can be yours if you send a . cashier's check for $460. C M Chen, 120 Columbus PI. Stamford CT 06907, (203) 322-7857. WANTED: MMD-1 microprocessor trainer in operating condition. Please state asking price in first offer. D C Shoemaker, 2000 A Foxridge, Blacksburg VA 24060, (703) 552-5764. FOR SALE: 48 K Apple II plus complete with two pad- dles, some programs, and cassette recorder with inter- face jack. Only three months old and in great condition. $1300. Eric Podell, 14949 Wellwood Rd, Silver Spring MD 20904. FOR SALE: Sold system, must sell software at super reduced prices. Dozens of CP/M, languages, business s/w (G/L, A/R, A/P, etc). Send SASE for complete list and prices. Dee B Moser, Box 638, Great Bend KS 67530. WANTED: June 1977 and October 1980 issues of BYTE. Will pay cash or trade March 1978, July 1980. August 1980, September 1980 issues. Also, I have for sale a God- bout 8 K S-100 4 MHz programmable memory board, assembled and working; $50. Thomas Kryst, 5242 E 24th St Apt D, Anchorage AK 99504. HICKOK DIGITAL MULTIMETERS MX-333 Model LX303 69 50 Ml Z Tech DMM 3V2- Digit LCD Readout MDdel WD 747 $7Q95 Beckman DIGITAL MULTIMETERS Model TECH 300 1 09 Model TECH 310 140 Model TECH 330 1 99 Simjuon DIGITAL MULTIMETERS Model 462 Model 463 „__ f 199 95$ 169 95 iSo 260 Meter ~~ Model 260-7 $QC Complete with nickel- Y"* cadmium batteries, AC charger/adapter, test leads Magnifier Lamp Precision ground and polished magnification lens Model LFM-1A Casio Calculator Calendar Watch Model C-atj $4250 Watclr BSSSSMJ 15MHzMiniscope ■ Rise time 11.7 nS or less ■ Built-in signal delay line ■ Flat Dual Trace ffl5" 30 MHz ^Triggered Scope Model 1479A Digital Pulsar Probe Model dp -ido 50 MHz Pulsar Probe Model dp-so L*J .© i __ i * • y©.| Model 1420 Autoranging DMM 3V2-Digit 0.1% Digital A Capacitance Meter | Model 3001 $ 233^^ Function Generator Model 2001 $"] 5795 Proto Boards Fully assembled *59 95 Logic Monitor • Automatically displays static and dynamic logic • Works with DTL, Model LM-1 HTL.TTL. and CMOS *59 95 Touch/Test 20 Multimeter 15 MHz Dual Trace Triggered M Miniscope X*fl Model MS-215 30 MHz Dual Trace Triggered MiniSCOpe Model ms-23o PK400 ™ ™ ^:*™ „ $7/199 4 Pc Standard Starter Kit -One I Ij Standard Command f f Console ■ Two (2] Lamp Modules ■ One (1] Appliance Module PK500 5 Pc Ultrasonic Starter Kit «0ue 11] Deluxe tAAQC Ullrascnic Command Consult; ■ One . 1 1 Hand Held Remote *HH M Unit ■ Two |2) Lamp Modules ■ One (!) Appliance Uoil LM501 Lamp Module S13.95 AM6D1 Appliance Module WS701 Wall Switch MorJuleS13. WS7I1 Wall Switch Module Willi independent On-Olf pQWfll billions S1Q.95 »! The Timer $5Q95 Miniature High Fidelity 3-Way Stereo Speakers $ 5 Q95 Chess Challenger 7 $ 79 95 , 3 Sensory Chess Challenger $ 110, Voice Sensory Challenger 24995 WAHL Cordless Soldering Iron $2995 Ttwtimo£-Sp.ot Circuit Tester Finds faulty components JJ quickly and easily $ 29 95 Model 5800 MURAPH0NE Cordless Telephone System Model $1-1 ft 300 I ■ V. Welter* WTCPN Controlled Output Soldering Station Model WTCPN $5750 ( Service Master Tool Kit $4995 Soldering Station l'MHil §upef6ase Model 70260 24995 In-Dash Car Stereos 8-Track AM/FM $EO50 Model JCS 420 *"■ Cassette AM/FM $5750 Model JCS 505 Digital Cassette AM/FM With ClOCk Model JCS 607 Graphic Equalizer Model GE 5000 $3995 US 6x9 3-Way$-|2 95 ea. Speakers ■ 20 oz magnet' Model BP2000-69 TRD 855 Conklin St. Farmingdale, N.Y. 11735 ■ Master Charge ■ BankAmericard ■ VISA ■ COD ■ Money Order ■ Check NY. Slate residenis add appropriate ADO FOR SHIPPING AND INSURANCE to I 250.00 i 3.50 SZ51.00 to 500.00 5.0O 501.00 to 750.DD 7.50 751. DO la 1000.00 10.00 over 1000.00 12 50 sxtra 414 April 1981 © BYTE Publications Inc fr°e l e l (800)645-9518 in N.Y. Slate call (516) 752-0050 ^^^^m Circle 289 on inquiry card FOR SALE: Speak & Spell with Speak-2-Me-2 installed by Percom Data. 230-word vocabulary plus program to form words from parts of vocabulary words. Complete with modified printer interface cable, user's manual, and driver programs. Set up for TRS-80 Level II with 16 K. In- structions for other computers. Worth $200, sell for $150. Joseph Wear, Rt 1 Box 83A, New Egypt NJ 08533, (609) 758-7193. FOR SALE: Okidata Model CP-110 friction-feed line printer, with RS-232 serial interface and uppercase/ lowercase character set. Prints 80 columns bidirectional at 110 cps. Uses 8V2-inch roll paper. Excellent condition. Cost $1349, asking $650. Virgilio DeCarvalho, Columbia- Princeton Electronic Music Center, 632 W 125th St, Room 318, New York NY 10027, (212) 280-3050. FOR SALE: H-8, serial I/O board, 20 K programmable memory, cassette, Extended BASIC. Up and running, all documentation included. First $600 takes. I ship. M H Endres, Box 8, Spirit Lake ID 83869, (208) 623-5911. FOR SALE: Magic Wand for TRS-80 Model II. Original disk and manual; $200. A A Schwartz, 6454 Camino Teatro, La Jolla CA 92037. FOR SALE: Burroughs Series B9352 video terminal. Has printer output, uppercase, and full cursor control. $300 plus freight. Steve Nelson, Box 150, Webster MN 55088. FOR SALE: PET 8 K computer with Soundware sound for PET, five tapes with programs including Microchess 2.0, and COMPUTE magazine for the PET. Original PET cost over $800, will settle for $675. Also, have ELF II computer complete with documentation and newsletters. Cost over $200, would like to trade for HP-41C card reader. Am interested in HP-41C equipment, willing to negotiate with PET and ELF II. Shaji Jacob, B27 Lincoln, Fort Morgan CO 80701, (303) 867-8162. FOR SALE: Tl #751 Silent 700 type printer. 10, 15, 30 cps, thermal, Baudot code, receive-only. Complete, but needs electrical work. With five rolls of paper and com- plete documentation. $100, you pay shipping, or trade for Heath H-9 terminal. Tom Hamilton, 1405 Washing- ton, Birmingham Ml 48009, (313) 647-5420 after 5 PM ET. FOR SALE: OSI Superboard with expansion, 18 K pro- grammable memory, 8 A power, 9-inch Sanyo monitor, and full enclosure; $650. 12-slot S-100 motherboard with 15 A power supply and termination; $150. Microdiver- sions Screensplitter 46 by 80 video display for S-100, brand new; $350. Plus much used equipment. Glenn Barnas, 280 Carmita Ave, Rutherford NJ 07070, (201) 935-0271. FOR SALE: SwTPC CT-64 terminal; $300 or best. AC-30 cassette interface, works on any 300 bps RS-232 line; $80 or best. MP-A2 6800 processor card with SWTBUG; $120 or best. All assembled and tested. USR-310 modem; $130. Keyboard; $50. Must sell soon. Charles Duff, 7007 N Sheridan #317, Chicago IL 60626, (312) 386-0311 leave message. FOR SALE: Multiterm printer Model T-4000: 55 cps, Diablo Hytype mechanism, tractor feed, ribbons, print wheels, many additional features, auto-underline, etc. $1700 or offer. Also, two Centronics 306C printers. $1200 each or offer. Michael Sloat, POB 982, Loma Linda CA 92354,(714) 796-2757. FOR SALE: PET owners, I have sixteen 4108 program- mable memory circuits guaranteed good. Will sell for $2.50 each or the entire lot for $35. Also, if your PET uses 4108s and they are in sockets, and you would like to up- grade to 32 K inexpensively, send $1 plus SASE for guar- anteed instructions. I am also looking for an inexpensive printer with 40/80 lines and Centronics-type parallel in- put. Harry E Leggans, Box 1179, APO New York 09023. FOR SALE: Alpha 16 mainframe includes processor, clock/controller, teletypewriter interface, 4 K memory, floppy-disk controller, and power supply. Also, much software and all manuals. $500 or offer. Edwin Karlow, Department of Physics, Loma Linda University, River- side CA 92515, (714) 785-2143. FOR SALE: Siemens FD100 mini floppy-disk drives with manuals, power supplies, and cases. $250 each or best offer. Western Digital 1771 floppy-disk controller cir- cuits. $B each. Marcy Durkee, 10265 Meadowwood Ln, Overland MO 63114. WANTED: Used computer-science books. Reasonably priced, in good condition; for personal use — only one copy of a title wanted. Examples: programming lan- guages, Knuth (volume 2), programming techniques, compiler design, applications, etc. J R Berman, 494 Forest Ave, Teaneck NJ 07666. FOR SALE: TRS-80 Model I, Level I, 4 K. Like new, hardly used. $500. Also, Apple games for trade— Invader, Asteroids, Sargon, etc. Randy Strouth, RR 5 Box 63, Faribault MN 55021, (507) 334-6585. FOR SALE: Digital Group Z80, Diskmon, Business BASIC, 64-character, 26 K dynamic; $1200. Two 8-inch disk drives and Digital Group controller; $1600. Key- board (needs repair) and 9-inch monitor; $250. Whole system for $2800. Wayne Dirks, 801 E 10th, Hutchinson KS 67501, (316) 663-3998 days. FOR SALE: TRS-80 Model III computer with 48 K pro- grammable memory, brand-new condition. Complete documentation plus several TRS-80 books. $950. Also, HP-41C programmable calculator with card reader plus blank cards, four memory modules, and MATH and STAT modules. $500. Alan J Grant, 530 44th St, Brooklyn NY 11220, (212) 436-1714 weekends or after 6 PM week- days. FOR SALE: Commodore PET 2001 computer with 8 K programmable memory and new 2.0 read-only mem- ories. Has on-board cassette and small keyboard. $50 deposit for shipping by UPS collect, balance due of $475. Dan Rubis, 19713 Alger, St Clair Shores Ml 48080, (313) 771-1392. BOMB )naoina Monit or Box Author|s) BYTE' sC Article # Page Article l 20 Recurrence in Numerical Analysis Davidson 2 36 Build a Low-Cost Logic Analyzer Ciarcia 3 46 The MicroAce Computer Searls 4 66 Digital Minicassette Controller Kahn 5 94 A Reformatter for CP/M and IBM Floppy Disks Lehman 6 102 Programming the Game of Go Millen 7 122 Build Your Own Turing Machine Willis 8 150 A Closer Look at the Tl Speak & Spell Vernon 9 188 Three Versions of APL Williams 10 218 An Introduction to Data Compression Corbin 11 252 Build An Intercomputer Data Link Wingfield 12 290 Three-Dimensional Computer Graphics, Part 2 Crow 13 348 PADDLES: Interfacing with Modular Combs and Breadboards Field WANTED: User's manual for Processor Technology 32KRA memory board. Steve Grant, 6055 E Washington Blvd, Suite 1035, Commerce CA 90040, (213) 725-1563. FOR SALE: Heath H-8, dual-drive H-17, H-9 video ter- minal, three 8 K programmable memory cards, serial/ cassette interface. Entire system for $1500 or sell in parts. Richard Berhain, 142 Jefferson Ave, Hasbrouck Heights NJ 07604, (201)288-1693. FOR SALE: North Star 2 system. Double-density, 48 K, with D C Hayes modem. Two serial and one parallel ports, SOROC IQ 140 terminal, and Centronics 779 trac- tor printer. Includes $2000 in business software. Six months old, in original boxes. $4895 or best offer. Also, DC Hayes modem 100; $325. Don, (615)526-7651. FOR SALE: Heath H-9 terminal; Heath H-10A reader/ punch; Tl 9900 single-board 16-bit microcomputer. Com- plete manuals and software included. Best offer. D Montgomery, Box 27, Oakland FL 32760, (305) 656-4293. FOR SALE: Super ELF with expansion board, 4 K static programmable memory, two I/O ports, Super Monitor, ASCII keyboard, 4-slot expansion case, power supply, RF modulator, Tiny BASIC cassette, and manuals; $250. Electric Crayon l/O-driven color graphics unit with 2 K memory, graphics firmware, manual, and built-in RF modulator. Alphanumerics and graphics expandable to 256 by 192. $200. Brent Elder, 7422 N Campus #7, Cornell University, Ithaca NY 14853, (607) 256-6750. FOR SALE: Model 33 ASR teletypewriter with manuals, paper-tape reader and punch, and stand. Mint condition, less than 100 hours on usage meter. $595 plus shipping. Automatic motor control installed and tested is $30 extra. Ken Brand, 421 Fairview Ave, Winchester VA 22601, (703) 662-0665 after 6 PM. WANTED: January and May 1979 BYTE. May and June 1978 Creative Computing. January, May, July, and December 1978 Kilobaud Microcomputing. Name your price. Robert Lansdale Jr, 18 Ashfield Dr, Etobicoke Ontario, M9C 4T6 Canada. January BOMB Results: Hand-Held Computers Readers responded to our January theme by voting top honors for "The Panasonic and Quasar Hand-Held Computers: Beginning a New Generation of Consumer Computers" by Gregg Williams and Rick Meyer (January 198 1 BYTE, page 34). Because Gregg is an employee of BYTE, the S 100 prize will go to Rick. Steve Ciarcia captured second place for his article "Elec- tromagnetic Interference," page 48 and receives $50. Third place was taken by Teri Li for his article "Whose BASIC Does What?" Fourth place went to Michael Keith and C P Kocher for their article "The NEC PC-8001 : A New Japanese Personal Com- puter." With the January issue, we began to collect votes for the BOMB (BYTE's Ongoing Monitor Box) through responses on one of the reader-service cards. This resulted in an increased number of votes and many favorable com- ments from readers. ■ April 1981 © BYTE Publications Inc 415 Reader Service Inquiry No. Page No. 311 AB Computers 387 189 ABM Products 292 293 Abrams Creative 384 56 Ackerman Digital 82 ' Action Computer 137 18 Adaptive Data & Energy Sys 23 336 Addmaster 392 49 Advanced Access 72 354 Advanced Comp Prod 402, 403 206 Advanced Micro Sys 312 108 Adventure Int'l 160 * ALF Products 78 40 Alpha Byte Storage 59 297 ALL Electronics 384 332 Alpha Omega Systems 392 308 American Busn Comp 386 172 American Square Comp 273 275 Ancrona 370, 371 276 Ancrona 372, 372 218 Anderson Jacobson 319 63 Anderson Peripherals 94 237 Apparat 330 10 Apple Computer 13 198 ASAP 303 226 ASAP 323 202 AshtonTate 307 188 Automated Equip Inc 291 * Avocet Sys Inc 294 156 Axiom 245 159 BASF 249 * Basis Microcomputer GMBH 177 285 John Bell Engineering 379 * Beta Comp Devices 315 295 BIS Inc 384 300 Bit Bucket, The 384 13 BIZCOMP 16 82 BMC 119 124 Bower-Stewart & Assoc 182 * BYTE Back Issues 246 135 BYTE Books 201 152 BYTE Books 233 181 BYTE Books 283 205 BYTE Books 311 17 Calif Comp Systems 21 353 Calif Digital 400, 401 243 Cambridge Learning Inc 333 93 Cavrl Systems 136 173 Central Data 275 143 Chrislln Industries 219 301 Clev Con Comp & Compnts 385 32 Colonial Data 50 248 Computer Age Inc 337 210 Computer Case Co 315 314 Computer City 388 20 Computer City Canada Inc 25 256 Computer Disc of Am 340 * Computer Factory, The 247 261 Computer Furn & Access 342 176 Computer Mall Order 278 104 Computer Marketing Corp 152 307 Computer Mart Inc 386 322 Computer Shopper 390 57 Computer Specialties 84, 85 271 Computer Tech Assoc 355 " Computer Warehouse 93 51 Computers R Us 74, 75 342 Computers Plus Inc 382 52 CompuMart 76, 77 80 CompuServe 116, 117 269 Computerware 345 183 Computex 286 249 COMPUTIME337 45 Compuview Products Inc 67 278 Concord Comp Components 374 51 Consumer Computers 74, 75 107 Corvus Systems 159 130 Coval 192 235 Cover Craft 328 * CPM User's Group 60 321 CPU Chop, The 389 1 Cromemco 1, 2 118 Crystal Computer 173 323 Custom Business Comp 390 298 Cyber Innovations 384 * Cybernetics Inc 138 242 Data Access 333 * Data Discount Center 146 346 Data Hardware 382 64 Datasouth Computer Corp 95 85 Datasouth Computer Corp 126 178 Datek280 84 Delta Products 123 89 Denver Software Co, The 131 113 Designers Software 167 146 Diablo (Dlv of Xerox) 223 266 Digiac Corp 343 75 Diglcomp110 * Digital Equlpmt Corp 241 87 Digital Graphic Systems 129 141 Digital Marketing 213 163 Digital Pathways 255 109 Digital Research 161 * Digital Research Computers 367 201 Discount Sftw Grp, The 306 65 DMA 346 168 Dual System Control Corp 265 258 Dymarc Ind 341 361 Dyna Byte C III 154 Dynacomp 239 317 DWP 388 252 Ecosoft 339 * Electravalue Industrial 342 74 Elron Computers Ltd 108 * Efficient Mngmt Sys 327 286 Electronic Center 380 22 Electronic Control Tech 28 339 Electronic Equip Unltd 392 270 Electronic Specialists 345 241 Ellis Computing 333 123 Epson 181 236 ER Hardins Mltry Madness 329 244 Escon 334 121 Essex Publishing Co 176 227 Essex Publishing 324 36 Exatron Inc 55 29 Eyring Research Inst 45 98 Faircom 144 213 Farnsworth Comp Center 317 289 Fordham Radio Supply 414 225 Forethought 323 25 Frederick Comp Prod 32 294 Frederlcktowne Comp 384 ' General Peripherals 388 111 Godbout Electronics 163 140 Godbout Electronics 210, 211 70 Mark Gordon Computers 104 139 GR Electronics Ltd 208 132 H & E Computronics 195 133 H & E Computronics 197 134 H & E Computronics 199 291 Hanley Engineering 383 207 Hayden Book Co Inc 313 48 Hayes Microcomp Prod Inc 71 31 Heath Company 49 27 High Technology Inc 34 39 Hobbyworld Electronics 58 299 Horizons Inc 384 53 Houston Instrument 79 54 Houston Instrument 79 15 IMS International 17 * Info Unltd Software 347 190 Innovative Sftw Appl 293 58 Integral Data Sys 87 59 Integral Data Sys 89 212 Integrand 317 259 Intelligent Control Sys 341 34 Intertec Data Systems 53 14 Intertec Data Systems 185 345 Introl Corp 382 335 Ipex Int'l Inc 392 5 Ithaca Intersystems 8 6 Ithaca Intersystems 9 351 Jade Computer Prod 396, 397 352 Jameoo Electronics 398, 399 230 JDR MICRODEVICES 325 331 Jlm-pak391 283 JR Inventory 378 30 Kern Publishing 48 105 Key Tronic 153 125 Konan Corp 81 341 Lab Microsystems 382 ■ Lanier 27 284 Lax Computer 378 * Leading Edge 237 257 Leapac Services 341 310 Leapac Services 386 232 Lee Products Co 317 88 Leo Electronics 130 101 Lifeboat 141 102 Lifelines 149 325 Linmar 390 106 Livermore Data Sys Inc 154 222 LNW Research 321 99 Lobo Drives Int'l 145 137 Logo Computer Systems 205 305 Lyben Comp 386 348 McHenry & Assoc 382 * McMillan Book Club 193 296 Macrotronics Inc 384 319 Magnolia Microsystems 388 103 Madbu Electronics 151 164 Mark of the Unicorn 257 144 Marot Software Systems Inc 221 174 Marymac Industries Inc 276 77 Mauro Engineering 112 100 Maxell Data 147 * Medlamlx 388 * Meas Sys & Controls 29, 121 221 Memtech 321 228 Meta Research 325 273 Meta Technologies Corp 358 169 MFJ Enterprising Inc 268 204 Micro Ace 309 38 Micro Age Computer Store 57 199 Micro Business World 304 20u Microbyte 305 * Micro Comp Discount Co 114 73 Micro Data Base Sys 107 To get further information on the products advertised in BYTE, fill out the reader service card with your name and address. Then circle the appropriate numbers for the advertisers you select from the list. Add a 1 5