SEPTEMBER 1981 Vol. 6, No. 9 $2.50 in USA/S2.95 in Cariaba A McGraw-Hill Publication tolsto ARTIFICIAL INTELLIGENCE SOUTHWEST TECHNICAL PRODUCTS CORPORATION 219 W. RHAPSODY SAN ANTONIO, TEXAS 78216 (512) 344-0241 Circle 334 on inquiry card. CROMIX* — Cromemco's outstanding UNIX + — like operating system cromix is just the kind of major development you've come to expect from Cromemco. After all, we're already well-known for the most respected software in the microcom- puter field. And now we've come up with the in- dustry's first UNix-lookalike for microcomputers. It's a tried and proven operating system. It's available on both 5" and 8" diskettes for Cromemco systems with 128K or more of memory. Here are just some of the features you get in this powerful Cromemco system: • Multi-user and multi-tasking capability • Hierarchical directories • Completely compatible file, device, and interprocess I/O • Extensive subsystem support FILE SYSTEM One of the important features of our CROMix is its file system comprised of hierarchical directories. It's a tree struc- ture of three types of files: data files, *CROMIX is a trademark of Cromemco, Inc. tUNIX is a trademark of Bell Telephone Laboratories directories, and device files. File, device, and interprocess I/O are com- patible among these file types (input and output may be redirected inter- changeably from and to any source or destination). The tree structure allows different directories to be maintained for different users or functions with no chance of conflict. PROTECTED FILES Because of the hierarchical structure of the file system, cromix maintains separate ownership of every file and directory. All files can thus be protected from access by other users of the system. In fact, each file is protected by four separate access privileges in each of the three user categories. TREMENDOUS ADDRESS SPACE, FAST ACCESS The flexible file system and general- ized disk structure of cromix give a disk address space in excess of one gigabyte per volume — file size is limited only by available disk capacity. Speed of access to disk files has also been optimized. Average access speeds far surpass any yet implemented on microcomputers. 'C COMPILER AVAILABLE, TOO Cromemco offers a wide range of languages that operate under cromix. These include a high-level command process language and extensive sub- system support such as cobol, Fortran IV, RATFOR, LISP, and 32K and 16K basics. There is even our highly-acclaimed 'C compiler which allows a program- mer fingertip access to cromix system calls. THE STANDARD O-S FOR THE FUTURE The power and breadth of its features make cromix the standard for the next generation of microcomputer operating systems. And yet it is available for a surprisingly low $595. The thing to do is to get all this capability working for you now. Get in touch with your Cromemco rep today. ra Circle 97 on Inquiry card. Cromemco TM ^^^^B 280 BERNARDO AVE., MOUNTAIN VIEW, CA 94040 ^^* Tomorrow's computers today (415)964-7400 Management Information Display Ultrasonic heart sector scan Process Control 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). •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. ra Cromemco i n J|^^^ 280 BERNARDO AVE., MOUNTAIN VIEW, CA 94040 ^^^ Tomorrow's computers today (415) 964-7400 Circle 97 on inquiry card. In The Queue Volume 6, Number 9 September 1981 Features 27a Look at NCC '81 by Steven K Roberts / A photo essay on the National Computer Con- ference held last May in Chicago. SO Build an Unlimited-Vocabulary Speech Synthesizer by Steve Garcia /An easy-to-use speech syn- thesizer can be designed using the Votrax SC-01 Speech Syn- thesizer Chip. 5oThe Xerox Alto Computer by Thomas A Wadlow / Some attributes of this research tool will be used in the next generation of personal computers. # 2 Tree Searching, Part 1 : Basic Techni- ques by Gregg Williams / A BASIC program allows your computer to solve a sliding-blocks puzzle. 112 One Step Forward— Three Steps Backup, Computing In the US Space Program by Patrick Stakem / The stringent demands of space exploration are met by several 8- and 1 6-bit microprocessors. 1 64 Artificial Intelligence by Steven K Roberts / Intelligent computers could ease the task of dealing with vast amounts of information, if certain problems can be solved. 1 80 A High-Level Language Benchmark by Jim Gilbreath / Speed benchmarks for more than fifty imple- mentations of high-level languages. 2wU Science Fiction's Intelligent Computers by Donald Byrd / Current knowledge of artificial intelligence puts science fiction to the test. 216 Symbolic Differentiation a la LISP by Ronald L Nl'COl / The list-manipulation abilities of LISP are easily adapted to differentiating mathematical functions. 238 Knowledge-Based Expert Systems Come of Age by Richard O Duda and John G Gaschnig / If an expert can do a specialized, self-contained task, so can a program. 284 The Atari Tutorial, Part I: The Display List by Chris Crawford / The display list allows you to mix both text and graphics on the same video-display screen. 3U4 Natural-Language Processing, The Field In Perspective by Gary Hendrix and Earl Sacerdoti / Systems that interact in English must have some under standing of human psychology and the world outside the computer. 414 The Emperor's Old Clothes by Charles Antony Richard Hoare / Mr Hoare, winner of the 1980 ACM Turing Award, reflects on his career and speculates on the future. Reviews 52 The Big Board: A Z80 System in Kit Form by David Thompson 1 46 Misosys Software's DISKMOD: Put Radio Shack's Editor/Assembler on Disk by Steve Hughes 1 50 MINCE, A Text Editor by Christopher O Kern 384 BYTE's Arcade: Big Five Software by Gregg Williams; The Prisoner by Bob Liddil 388 Three Microcomputer LlSPs by Steven P Levitan and Jeffrey G Bonar 436 Interactive Fiction: Six Micro Stories by Bob Liddil Nucleus 6 Editorial: Odds and Beginnings 1 Letters 34, 1 08 Book Reviews: Principles of Artificial Intelligence; Turtle Geometry 110, 383, 412 BYTE's Bugs 162 Programming Quickies: Changing a BASIC FOR . . . NEXT Loop into a REPEAT . . . UNTIL Loop 354 BYTELINES 360 Ask BYTE 364 Books Received 366 Clubs and Newsletters 372 Event Queue 383 Software Received 412, 425 BYTE's Bits 426, 428, 435 Technical Forum: Microcomputers and the IRS; Add Dual Trace and Delayed Sweep to Your Oscilloscope; How to Build an Inexpensive Cassette Level Indicator 432 System Notes: An Almost Optimum Z80 Memory Test Program 441 What's New? 494 Unclassified Ads 495 Reader Service 496 BOMB, BOMB Results BITE Page 38 Page 52 Page 58 Page 1 1 2 September 1981 © BYTE Publications Inc 3 li'nfi Editor in Chief Christopher Morgan Managing Editor Mark Haas Technical Editors Gregg Williams. Senior Editor; Richard S Shuford; Curtis P Feigel; George Stewart; Arthur Little; Charles Freiberg, New Products Editor; Steve Ciarcia, Mark Dahmke, Consulting Editors; Jon Swanson, Draftsman Copy Editors Be' erly Cronin, Chief; Faith Hanson; Warren Williamson; Anthony J Lockwood; Ann Graves; Jane Harrigan Assistants Faith Ferry; Debe Wheeler; Karen A Cilley; Susan Ferber Production Nancy Estle, Director; Christine Destrempes, Asst Director; Wai Chiu Li; Jonathan M Graves; Patrice Scribner; Karen Labaugh; Damian Henriques; Sherry McCarthy, Chief Typographer; Debi Fredericks; Donna Sweeney; Valerie Horn Advertising Thomas Harvey. Director; Marion Gagnon; Rob Hannings; Marilyn Williams; Deborah Porter; Vicki Reynolds; Jacqueline Earnshaw, Reader Service Coordinator Circulation Gregory SpiGfaden. Manager; Andrew Jackson, Asst Manager; Agnes E Perry; Barbara Varnum; Louise Menegus; Pinky Krulis; James Bingham, Dealer Sales; Carol Baniecki, Asst. Controller's Office Daniel Rodrigues, Controller; Mary E Fluhr, Acct. & D/P Mgr; Karen Burgess; Jeanne Cilley; Mary Beth Ireland; Linda Fluhr Traffic N Scott Gagnon; Michael Bacon; Cynthia Damato Receptionist Joanne Colburn 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 Computerized natural-language processing is one of the many topics that have come to be associated with artificial intelligence. As Robert Tinney's cover suggests, computers someday may be able to read and understand War and Peace. Steven Roberts' article "Artificial Intelligence" is a good place to start, and "Natural-Language Processing, The Field in Perspective," by Gary Hendrix and Earl Sacerdoti, addresses this month's theme. Donald Byrd discusses the point at which fact meets fiction in "Science Fiction's Intelligent Computers," and Ronald L Nicol focuses on the artificial intelligence communi- ty's primary language in "Symbolic Differentiation a la LISP." Steve Ciarcia has prepared an alternate way of eliciting speech from a com- puter with "Build an Unlimited-Vocabulary Speech Synthesizer." We also have a description of the Xerox Alto computer by Thomas A Wadlow, and we take a look at NASA's high-flying computing machinery in Patrick Stakem's "One Step Forward— Three Steps Backup." BYTE is published monthly by BYTE Publications Inc. 70 Main St, Peterborough NH 03458, phone (603) 924-9281, 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, S2I for one year, S38 for two years, S55 for three years. $43 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, $4.00 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 © 1 98 1 by BYTE Publications Inc. All rights reserved. Where necessary, permission is granted by the copyright owner for libraries and others registered with the Copyright Clearance Center (CCC) to photocopy any article herein for the base fee of S 1 .00 per copy of the article or item plus 25 cents per page. Payment should be sent directly to the CCC, 2 1 Congress St, Salem MA 01 970. Copying done for other than personal or internal reference use without the permission of McGraw-Hill is prohibited. Requests for special permission or bulk orders should be addressed to the publisher. BYTE 8 is available in microform from University Microfilms International, 300 N Zeeb Rd, Dept PR, Ann ' Arbor Ml 48106 USA or 18 Bedford Row, Dept PR, London WCIR 4EJ England. 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 MIDWEST (312) 966-0160 MID ATLANTIC (212) 682-5844 Hajar Associates Hajar Associates Hajar Associates 280 Hillside Ave 5225 Old Orchard Dr 52 1 Fifth Ave Needham Heights MA 02194 Skokie IL 60076 New York NY 10017 NORTHWEST (41 5| 964-0706 SOUTHWEST (714) 540-3554 SOUTHEAST (305) 886-7210 Hajar Associates Hajar Associates Hajar Associates lOOOEIwellCt. Suite 227 3303 Harbor Blvd 1 220 Prairie Lane Palo Alto CA 94303 Suite K-4 Costa Mesa CA 92626 Apopka FL 32703 September 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 Forecast MICROANGELO HIGH RESOLUTION GRAPHICS SINGLE BOARD COMPUTER 512x480 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 SI 00 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. SOON 8455-D Tyco Road • Vienna, Virginia 22180 • TWX: 710-831-9087 • (703) 827-0888 Circle 321 on inquiry card. Circle 115 on inquiry card. MAINTAIN PROJECT CONTROL WITH MILESTONE™ Jf - cutting down on shared time f^ and having his own tamper-proof data base, ^r H His Apple can handle formulas with up to 80 vari- ables and test parameters on 250 different optical glasses. He can even use BASIC, FORTRAN, Pascal and Assembly languages. And Apple s HI-RES graphics come in handy for design. Reddy looked at other microcomputers, but chose Apple for its in-depth documentation, reliability and expandability. You can get up to 64K RAM in an Apple II. Up to 128K RAM in our new Apple III. And there's a whole family of compatible peripherals, including an IEEE-488 bus for laboratory instrument control. Visit your authorized Apple dealer to find out how far an Apple can go with scientific/ technical applications. It'll change the way you see things. The personal computer.Bj^nipplCZ for the authorized dealer nearest you, call (800) 538-9696. In California, call (800) 662-9238. Or write: Apple Computer Inc., 10260 Bandley Dr., Cupertino, CA 95014. Circle no. 3 for more information or Circle no. 25 for special OEM information SOFTWARE DEUELOPmEITT TOOLS FOR mDUSTRV 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. Then plug our EPR-48 board into your S-100 system to program the 8748 EPROM version. (Similar packages for 8051 and TMS9940E coming soon.) 8048 Development Package . . . $574.00 EPR-48 alone $449.00 PROM EMULATOR BOARD Debug dedicated systems quickly. Our PSB-100 PROM Emulator is an S-100 board with up to 8K of RAM. Cable with 24-pin plug replaces PROM(s) in your target system for instant program test- ing. PSB-100 PROM Emulator . . $445.00 w/ 2K RAM * Trademark of Digital Research 804 south state St. dover, delaware/1 9901/302-734-0151 Visa and Mastercharge accepted. We ship on 8" single-density. Ask us about other formats. OEM AND DEALER INQUIRIES INVITED. 14 September 1981 © BYTE Publications Inc Letters MIT Defends Logo Policy This is in response to Mr Stephen Hain's letter, which appeared in the August 1981 BYTE and which raised questions about the release and distribution of the MIT Apple Logo programming language. (See 'Unpublished Apple Logo," page 32.) As correctly noted in the original BYTE article ("Logo for Personal Computers," by Harold Nelson, June 1981 BYTE, page 36), the development of the MIT Apple Logo programming language was spon- sored in part by the National Science Foundation (NSF). Discussions between MIT and NSF with respect to mechanics of release and distribution have been underway. Licensing authority has now been formally requested by MIT; and, as soon as permission is granted, it is the in- tention of MIT to complete licensing ar- rangements that will ensure the broadest possible dissemination of this important programming language. Kenneth A Smith Associate Provost MIT 545 Technology Sq Cambridge MA 02139 Comments on Software Piracy The following comments by our readers were solicited through Chris Morgan's May 1981 BYTE editorial "How Can We Stop Software Piracy?" I commend Chris Morgan and BYTE for addressing a subject too frequently over- looked. Software piracy has, indeed, reached an appalling level, while some- how retaining an odd sort of tacit protec- tion — that of being a "gentleman's" crime. Chris Morgan's statement that "soft- ware piracy ... is not just illegal — it's unethical" couldn't have been more to the point. It is unethical. Shamefully so. To those who attempt to protect their works, this can't be stressed enough. The courts and various legal bodies are slow, but they are working toward resolving some of the piracy problems. Many talented people are working madly devising clever tricks to prevent the theft — all because there are those who think it's better to have something for nothing than it is to ethically exchange with those who worked hard to produce something of value. No doubt the thieves have justified their actions. Maybe they think the "system" is unfair; maybe they think they can't afford the programs they so dearly want; maybe they don't even think at all. But one thing is certain: they haven't developed soft- ware packages themselves and then had them ripped off to the tune of thousands of dollars. That much we know. It's a shame that one's fellow man is called upon to police another. One would like to believe that we're fair and honest people. It appears not all of us are. Hence, in addition to the efforts of our legislators and programmers, those ethical souls who learn of piracy need to do something ef- fective about it. If simple reasoning with a software pirate won't do it, then reporting the matter to the developer just might. While contrary to the childhood dictum "don't be a tattletale," it could help to cur- tail a growing cancer in the industry. The Association for Software Protec- tion (ASP) is a newly formed group dedi- cated to eradicating the piracy problem. At present it is addressing — in the main — the problems faced at the mini- computer level. Nevertheless, the piracy problem branches across all levels, and any group or individuals interested in organizing an antipiracy microcomputer group are invited to contact ASP. In addition to my activities with ASP, I am the Software Protection Director at Mini-Computer Business Applications in Glendale, California. Robin Robinson Association for Software Protection 10143 Leona Ave Tujunga CA 91042 Chris Morgan's and BYTE's concern with software piracy is well placed, and BYTE's coverage is excellent, but there are wider perspectives to add. For millennia, humanity moved around picking and chasing things to eat. The Agricultural Revolution meant the com- plete transformation of social arrange- ments, which resulted in the invention of private property, towns, political institu- tions, writing, ruling classes, fortifica- tions, the ownership of land, etc. Things were like that for a few millen- nia more. For the last couple hundred Letters continued on page 18 Disk Storage: It's No Place to Compromise. A dependable disk system means everything to the high- performance operation of your computer. At Percom, we know this. And we do something about it. For example, the connectors on our TFD drive systems are gold plated. Why? Because solder-plated contacts oxidize, forming an in- sidious insulation that can cause erratic operation. And then total failure. Gold-plated connectors are just one way we make better drive systems than the competi- tion. Now #1 for the Model III Quality Percom TFD drives provide more features, cost less. Add-on drives start at only $439.00. Complete First-Drive Sys- tems start at only $749.95. Features: "Flippy" Capability — Record your To order products, or for the name of your authorized Percom retailer, call toll free: 1-800-527-1592. PERCOM DATA COMPANY, INC. 211 N. KIRBY GARLAND, TEXAS 75042 (214) 272-3421 programs and data on either side of a dis- kette. Greater Storage Capacity — Store 180 Kbytes — formatted — on one side of a 40-track TFD drive. Store over twice as much on a TFD 80-track drive. Think Megabytes — Your TFD drive controller will handle up to four drives. You can access almost 1.5 million bytes of on-line program and data files. Either Add-in or Add-On — Your TFD First Drive System can be either internal (add-in) or external (add-on). In either case, you get a complete system in- cluding the disk controller, drive, power supplies and disk-operating software. BASIC-Language DOS — Included on diskette with each First Drive System is Percom's OS-80/IH'™. This easy-to-use disk-operating system loads into 7 Kbytes of RAM and then frees the drive for other use. With OS-80'" programs, you can have full, read-write interchangeability between Model I and Model III diskettes. Or Model III TRSDOS* — TFD 40 track drives work with Tandy's Model III TRSDOS. without modification. For 80- track operation, TRSDOS can be easily modified with diskette patches supplied. Still #1 for the Model I Besides greater storage capacities, more quality control measures and lower pri- ces, all Percom Model I drives are rated for double-density operation. Plug a DOUBLER"* in your Expansion Interface and enjoy the same double- density disk storge capacity as Model III owners. Included with each DOUBLER is a TRSDOS compatible double-density disk-operating system. DOUBLEZAP programs are available for upgrading oth- er popular DOSs for DOUBLER opera- tion. And our double-density version of OS-80™ costs just $49.95. Of course you don't have to upgrade your Model I for double-density opera- tion to use Percom disk drives. But it's nice to know you can. Percom TFD drives for the TRS-80* Model I are available in 40-, 77- and 80- track versions, in 1-, 2- and 3-drive con- figurations. Prices start at $399.00. System requirements: Model III TFD drives work with a 16-Kbyte system (min) and Model III BASIC. The initial drive must be a first-drive system. An op- ional interconnecting cable is available for expand- ng with external drives #3 and #4. Model I TFD drives work with a 16-Kbyte system (min) equipped with an Expansion Interface. Level II BASIC and DOS software, and an interconnecting cable. Two- nd four-drive interconnecting cables are available rem Percom. Yes ... I'd like to know more about the best for my TRS-80 computer. Send me free literature about quality Percom products. □ Model I □ Model III Send to PERCOM DATA COMPANY, Inc., Dept. 8 211 N. Kirby St. Garland TX 75042 city state zip phone number MAIL TODAY! B01 '" trademark ol Percom Data Company, Inc. 'trademark of Tandy Radio Shack Corporation which has no relationship to Percom Data Company. PRICES AND SPECIFICATIONS SUBJECT TO CHANGE WITHOUT NOTICE. TWELVE STRONG HEATH/ZENITH YOUR Pick a strong partner A computer purchase is the beginning of a long term partnership between you and the people you buy from. Your ongoing need for software and accessories re- quires a partner who will stand by you with a growing line of products. And nowhere will you find a more com- plete line of hardware, software and accessories than at your Heathkit Electronic Center. Here are twelve strong reasons to make Heath/Zenith your partner. 1. The All-in-One Computer The heart of the Heath/Zenith line is the stand-alone 89 Computer. It's a complete system with built-in 5 1 /4-inch floppy disk drive, professional keyboard and keypad, smart video terminal, two Z80 microprocessors, and two RS-232C serial I/O ports. It comes with 16K RAM, expandable to 64K. 2. Peripherals These include the popular Heath /Zenith ^^^^■T" 19 Smart Video Terminal, loaded with 1 professional features. And the 14 Line m^i Printer, priced as low as $495. Other pW printer brands are on display, B^ including high- speed, typewriter-^a quality printers. ^aa, 3. Software *^^^^J Word processing, includes reliable, easy-to-use Zenith ElectronicTyping and powerful, full-featured WORDSTAR. Small Business Programs, feature General Ledger and Inventory Control. HUG, Heath Users' Group, offers members a library of over 500 low-cost programs for home, work or play. 4. Programming Languages For your own custom programs, Microsoft languages are available in BASIC (compiler and interpreter), FORTRAN and COBOL. 5. Operating Systems Three versatile systems give you the capability to per- form your specific tasks. CPIM by Digital Research makes your system com- patible with thousands of popular CP/M programs. UCSD P-System with Pascal is a complete program development and execution environment. HDOS, Heath Disk Operating System gives you a sophisticated, flexible environment for program construction, storage and editing. , 6. Utility Software Expand the performance range of your computer with a broad selection of utility tools, including the best of Digital Research and the complete line of innovative Softstuff products. 7. Disk Systems The 8-inch Heath/Zenith 47 Dual Disk System adds over 2 megabytes of storage to your 89 Computer. Diskettes are standard IBM 3740 format, double-sided, double-density. The 5V*-inch 87 Dual Disk System adds 200K bytes of storage to your 89. Both disk systems feature read/write protec- tion and easy plug-in adaptability. 8. Self-Study Courses Learn at your own pace with Programming Courses that teach you to write and run your own programs in Assembly, BASIC, Pascal or COBOL. A course on Computer Concepts for Small Business gives you the understanding to eval- uate the ways a computer can benefit your business. Personal Computing is a complete introduction to the fundamentals for the novice. Every Heathkit/ Zenith course is pro- fessionally designed for easy, step-by- step learning. All Heath I Zenith Computer Products are available completely assembled and tested for commercial use. Or in easy to-build, money-saving kits REASONS TO MAKE COMPUTER PARTNER 9. Expansion Options Communicate with the outside world through a Three- port EIA RS-232C Serial Interface. Expand RAM to 64Kwith easy-to-install expansion chips. 10. Accessories Your Heathkit Electronic Center has the latest in modems, black-and-white and ""color video monitors, computer furniture and a full line of supplies, accessories, books and parts. 11. Service No one stands by you like Heath/Zenith We help you get your system up and running smoothly. Service is avail- able from trained technicians, over the phone or at one of 56 Heathkit Electronic Centers. 12. Value Your money buys you more because Heath/Zenith prices are among the industry's most competitive. Make your own comparison and find out how much you can save. Complete, integrated computer hardware and soft- ware, designed to serve you and to grow with you - that's what to look for in a strong partner. And with Heath/Zenith you get it all under one roof. All at your Heathkit Electronic Center Pick the store nearest you from the list at right. And stop in today for a demon- stration of the Heath/Zenith 89 Computer System. If you can't get to a store, send $1.00 for the latest Heathkit* Catalog and the new Zenith Data Systems Catalog of assembled commercial computers. Write to Heath Co., Dept. 334-814, Benton Harbor, Ml 49022. Visit Your Heathkit Electronic Center* where Heath/Zenith Products are displayed, sold and serviced. PHOENIX, AZ 2727 W. Indian School Rd. 602-279-6247 ANAHEIM, CA 330 E. Ball Rd. 714-776-9420 CAMPBELL, CA 2350 S. BascomAve. 408-377-8920 ELCERRIT0.CA 6000 Potrero Ave. 415-236-8870 LA MESA, CA 8363 Center Dr. 714-461-0110 LOS ANGELES, CA 2309 S. Flower St. 213-749-0261 POMONA, CA 1555 N. Orange Grove Ave. 714-623-3543 REDWOOD CITY, CA 2001 Middlefield Rd. 415-365-8155 SACRAMENTO, CA 1860 Fulton Ave. 916-486-1575 WOODLAND HILLS, CA 22504 Ventura Blvd. 213-883-0531 DENVER, CO 5940 W. 38th Ave. 303-422-3408 AVON.CT 395 W. Main St. (Rt. 44) 203-678-0323 HIALEAH, FL 4705 W. 16th Ave. 305-823-2280 PLANTATION, FL 7173 W.Broward Blvd. 305-791-7300 TAMPA, FL 4019 W.Hillsborough Ave. 813-886-2541 ATLANTA, GA 5285RoswellRd. 404-252-4341 CHICAGO.IL 3462-66 W.Devon Ave. 312-583-3920 downersgrove.il 224 0gdenAve. 312-852-1304 INDIANAPOLIS, IN 2112 E. 62nd St. 317-257-4321 MISSION, KS 5960 Lamar Ave. 913-362-4486 LOUISVILLE, KY 12401 ShelbyvilleRd. 502-245-7811 KENNER.LA 1900 Veterans Memorial Hwy. 504-467-6321 BALTIMORE, MD 1713 E. Joppa Rd. 301-661-4446 ROCKVILLE.MD 5542 Nicholson Lane 301-881-5420 PEABODY, MA 242AndoverSt. 617-531-9330 WELLESLEY, MA 165 Worcester Ave. 617-237-1510 DETROIT, Ml 18645 W. Eight Mile Rd. 313-535-6480 E.DETROIT, Ml 18149 E. Eight Mile Rd. 313-772-0416 HOPKINS, MN 101 Shady Oak Rd. 612-938-6371 ST. PAUL, MN 1645 White Bear Ave. 612-778-1211 BRIDGETON.MO 3794McKelveyRd. 314-291-1850 OMAHA, NE 9207 Maple St. 402-391-2071 ASHURYPARK.NJ 1013 State Hwy. 35 201-775-1231 FAIR LAWN, NJ 35-07 Broadway (Rt. 4) 201-791-6935 AMHERST, NY 3476 Sheridan Dr. 716-835-3090 JERICHO, LI. NY 15 Jericho Turnpike 516-334-8181 ROCHESTER, NY 937 Jefferson Rd. 716-424-2560 N.WHITE PLAINS, NY 7 Reservoir Rd. 914-761-7690 CLEVELAND, OH 28100 Chagrin Blvd. 216-292-7553 COLUMBUS, OH 2500 Morse Rd. 614-475-7200 TOLEDO, OH 48 S. Byrne Rd. 419-537-1887 WOODLAWN.0H 10133 Springfield Pike 513-771-8850 OKLAHOMA CITY, OK 2727 Northwest Expressway 405-848-7593 FRAZER, PA 630 Lancaster Pike (fit. 30] 215-647-5555 PHILADELPHIA, PA 6318 Roosevelt Blvd. 215-288-0180 PITTSBURGH, PA 3482 Wm. Penn Hwy. 412-824-3564 WARWICK, Rl 558 Greenwich Ave. 401-738-5150 DALLAS, TX 2715 Ross Ave. 214-826-4053 HOUSTON, TX 1704 W. Loop N. 713-869-5263 SAN ANTONIO, TX 7111 Blanco Road 512-341-8876 MIDVALE, UT 58 East 7200 South 801-566-4626 ALEXANDRIA, VA 6201 Richmond Hwy. 703-765-5515 VIRGINIA BEACH, VA 1055 Independence Blvd. 804-460-0997 SEATTLE, WA 505 8th Ave. N. 206-682-2172 TUKWILA.WA 15439 53rd Ave. S. 206-246-5358 MILWAUKEE, Wl 5215 W. Fond du Lac 414-873-8250 ' Units of Veritechnology Electronics Corporation in the U.S. Prices and specifications subject to change without notice. HEATH/ZENITH Your strong partner Circle 243 on inquiry card. 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 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 $259. data systems Z19 Video Terminal Limited Time $799 List $995 BaKEEES HP-BRA Desk-Top Computer List $3250 $2749 HP- 83 ust $2250 Special $1749 F.O.B. shipping point. All prices subject to change and all offers subject to withdrawal without notice. Advertised prices are for prepaid orders. Credit card and C.O.D. 2% higher. C.O.D. may require deposit. - WRITE FOR FREE CATALOG - MiniMicroMart 943 W. Genesee St. Syracuse, NY 1 3204 (315) 422-4467 18 September 1981 © BYTE Publications Inc Letters. years, however, most people have run machines. As we see and know, every society and culture in the world has been thrown into turmoil because, once again, the world is changing rapidly. "Classic" economics is based on ma- terial commodities: if there are you and me and a loaf of bread, either you get it, or I get it, or we split it. No existing school of economics, however, deals with the fact that if you give me some information, you still have it. Material commodities get "thinner" when spread out, while infor- mation gets "thicker" as it's spread out. Two-thirds of the jobs in the United States are informational. Money, proper- ty, and many other foundations of society have begun transmuting. Software piracy is a logical area for difficulties to emerge first. Where else can you go into business selling pure thought? The more we are aware, and the more we examine and discuss the big implica- tions, the less surprised we'll be. Neil Rest 1457 Gregory Chicago IL 60640 Congratulations to Chris Morgan for his timely attention to the software-piracy controversy. The following specifications may be useful in evaluating solutions pro- posed for this problem: • There shall be no realistic means for defeating the protection mechanism, re- gardless of the attacker's technical sophistication or familiarity with the design of the software-protection system. • The software product shall not have to be customized for each licensee. • The user shall have to purchase one, and only one, hardware device to use all pro- tected software. Once this device is at- tached to the computer, the user shall be able to forget it exists. • The device shall be the same, regardless of the computer system with which it is used; and it shall be compatible with ex- isting computer systems. • There shall be no degradation of the reliability or versatility of a computer system as a result of this device. • The cost of the device shall be minor compared to the cost of the least expen- sive (but practical) system on which pro- tected programs will be used. • The logistical support of the protection system shall require no effort on the part of the software publisher. • The system shall restrict the use of pro- tected software to the licensed user for a licensed period of time. I would appreciate the comments of BYTE's readers on the applicability and completeness of these specifications. At Salcris Corporation, we are currently field-testing our Chrono-Guard Software Protection System, which meets these specifications. Software protection is our only business and, while we believe we have a carefully thought-out solution to the industry's problems, we value con- structive criticism. Thomas C Donald President Salcris Corporation 1 Office Park Cr Birmingham AL 35223 In the May 1981 BYTE there were several excellent articles on what I regard as one of the most severe problems facing the computer-software industry today — theft of software. (See Chris Morgan's "How Can We Stop Software Piracy?", page 6; Christopher Kern's "Washington Tackles the Software Problem, " page 128; and Stephen Becker's "Legal Protection for Computer Hardware and Software," page 140.) I know of several companies, mine included, that will not sell packaged software because of the theft problem. The constant "reinvention of the wheel" that results from the reluctance to sell software is one of the leading factors con- tributing to the already poor productivity of the industry. If we are not to stagnate and allow foreign competition to steal our software lead, an early solution to this problem must be found. One article mentioned several rather complex hardware solutions that are cur- rently proposed to help solve the prob- lem. While most of the hardware dis- cussed would provide more or less proces- sor-independent solutions that would re- quire no industry-wide effort to help solve the problem, I feel that these efforts will lead to an expensive and relatively inse- cure solution. The cheapest and most reliable answer is not a hardware solution (although hardware must play a key role), but "self-protecting" software. How can software be made to protect itself? Well, I am not aware of any proces- sor on which this is possible today, but a minor processor modification could easi- ly, cheaply, and effectively accomplish Circle 246 on inquiry card. Mountain Computer CPS Multifunction Card TM he Only Interface Card You Need! Connecting a Parallel Printer? Epson®- Centronics®- IDS Paper Tiger®- CPS handles all these primers and others with on-board intelligence to provide paging and other features found on no other card. Connecting a Serial Printer? Diablo® Qumc^NEC - TI 800 Series® CPS handles these printers and others with standard RS-232 interface providing selection of baud rates, handshakes, paging, and more. Connecting a Modem or Terminal? Hayes Smartmodem - Novation CAT - M & R Pennywhistle - CPS handles these and others with full/half duplex operation, baud rate selection, and even a transparent terminal mode which includes a dual mode feature that permits printing of text to parallel printers while 'on-line' eliminating the need for special terminal software— and more. Connecting with the Time? The on-board calendar/clock provides real time and date information including day of week, day, month, year, hours, minutes, and seconds for any application requiring a time stamp— battery backed-up for over two years! Connecting with The Source? Used with a modem, CPS provides the connection to informa- tion utilities, such as The Source!® Dow Jones, and others. Additionally, CPS provides the connection to big-time electronic mail with programs such as Micro Courierand Micro Telegrarn? and other data transfer programs. Connect with Easy Use! CPS has no switches to set! All functions on the card an from a user program. Menu driven screens set up your choice of all functions on CPS and store them on-board in CMOS RAM—battery backed-up (including the clock) for over two years! To change parameters, run the set-up program again— or use special commands from your keyboard. Furthermore, most existing software programs are immediately usable with CPS. Phantom Slot Capability permits assignment of CPS' functions to your software's pre-defined slots. Connect with Your Apple®Dealer Drop by your Apple dealer and see how the CPS MultiFunction Card provides the most comprehensive capabilities for RS-232C serial interface, parallel output, and real-time calendar/clock of any card available today — all on one card— at one low price- competitive with any one of the three or more single function cards that it replaces. £* Mountain Computer INCORPORATED 300 El Pueblo Road, Scotts Valley, CA 95066 (408)438-6650 TWX: 910 598-4504 ■> Registered trademarks Letton this. The biggest problem will be to get everyone to cooperate and adopt a stan- dard approach. IBM was on the right track to solving the problem several years ago, but some- one, somewhere, dropped the ball, and the solution became only half-imple- mented. Anyone who has ever done some systems programming work on an IBM S/370 is probably aware of the privileged instruction "STORE PROCESSOR ID." This instruction provides systems pro- grams with the processor serial number and other system information, such as whether VM/370 is the system-control program, etc. This instruction provides system-level programs (and even microcode) some degree of theft protec- tion, although its primary purpose is to provide a method by which system pro- grams can determine what model pro- cessor is being used. The big problem from the applications program side, which is where IBM left the scene, is that there is no easy method to access the in- formation provided by this instruction. To solve the software-theft problem, the entire industry must provide some method by which the user's application program can determine such information as the make, model number, and serial number of the host processor. Additional- ly, it must be constructed in a manner such that it would be next to impossible for the user to modify the factory-sup- plied information. The addition of one in- struction to the processor repertoire would undoubtedly increase the cost of the hardware, but the increase would not even approach the price of the cheapest protection method that I have seen pro- posed. The only disadvantages to this ap- proach are that it would not be easily ap- plicable to existing systems (most of which will probably not be around more than five years anyway, so why worry7) and it would preclude the distribution of source code (you would not want some- one to discover how you encrypt the pro- cessor ID and check against the licensed processor ID). I welcome any comments. Jon R Kibler President Southeastern Computer Services Inc POB 160124 Mobile AL 36616 Chris Morgan's May 1981 BYTE editorial mentioned a software-protection 20 September 1981 © BYTE Publications Inc Circle 53 on inquiry card. MAKING MINIS OUT OF MICROS. Here's the system builder's solution for successful computers and applications. Push in the CCS component. Push in the operating software. And push on with your ap- plication. CCS systems and compo- nents are designed to go together quickly, and to keep running reli- ably, with a proven return rate of less than 1%. And you get performance. The systems deliver hardware vectored interrupts and the capability to inter- leave DMA data transfers with rates as high as two megabytes per sec- ond, plus bank select memory of up to 51 2K bytes. This 8-bit system pro- vides single user, multiuser, and multitasking capability with ample speed to prevent operator waiting or loss of incoming real-time data. The systems are available with CP/M or MP/M operating systems. For real-time or multiuser applica- tions, the CCS OASIS real-time multitasking operating system sup- ports re-entrant programs and relocatable code modules, with Circle 52 on inquiry card. O Please have a sales representative call me. O Please send more information on CCS Systems and Expansion Modules. California Computer Systems 250 Caribbean Drive Sunnyvale, CA 94086 (408)734-5811 i facilities for task-to-task communi- cation, file protection, time-of-day bookkeeping, spooling, task overlay, dynamic memory management, ISAM file structures and device- independent I/O. CCS OASIS in- cludes debug, text editing, linkage, and file sort utilities; the system supports a host of existing lan- guages, applications, and utilities from a range of vendors. Powerful computer systems you can configure to your demanding requirements quickly, and with con- fidence. Choose from a variety of systems. Expand with CCS board- level modules for memory, disk con- trol, high-speed arithmetic, and I/O, plus subsystems for floppy and hard disk storage. If you sell, install, or use com- puter systems, you should know more about the CCS product line. We've got a lot more to tell. Tear out and return the coupon for more information. Or call. CP/M and MP/M are trademarks of Digital Research. OASIS is a trademark of Phase One Systems. scheme based on encrypting programs. Since mid-1979, all Sentinel computers have used a somewhat more convenient scheme. In our systems (based on one or more Intel 8086s), the machine's serial number is available to the operating sys- tem. The operating system recognizes en- crypted application programs and uses the serial number as a key to decrypt them as they are loaded from floppy-, Win- chester-, or bubble-memory-disk storage. This protects Sentinel's investment in our comprehensive set of financial ap- plication programs and lets us give our distributors and end users utility pro- grams that can copy any of our software. We also give Sentinel distributors the tools to encrypt their own programs. Vernon J Schryver Product Development Manager Sentinel Computer Corporation 9902 Carver Rd Cincinnati OH 45242 I read Chris Morgan's editorial on soft- ware piracy with interest. The two sides of the software protection/duplication controversy were drawn as "the vendor's need for security" versus "the user's need for backup copies for reliability." My experience with software products, both large and small, has revealed an even greater need on the part of software pur- chasers than that of backup copies. This need is for modifiable and configurable software. A few years ago, most small- computer systems were either home-built or installed and used without modifica- tion from the time they left the factory. In the case of personal computers, peripher- als were few and were usually made or distributed by the frame manufacturer. Things are different today — and this has given rise to the need for user-configur- able software. For example, my firm's Apple II com- puter contains interface cards for four peripheral devices: the disk system, printer, modem, and an 80-column video card. Only one of these is an Apple Com- puter product. Nearly every software product we have purchased has required reconfiguration — sometimes a lengthy project — to support these devices. I am very reluctant to purchase any software packaged on a copy-protected disk, an "unreadable ROM," or otherwise immune to modification to suit our needs. Vendor support of nonstandard hardware is an admirable goal, but we realize that it One Man's Dilemma / would never break into a computer store and steal a disk drive, a printer, or a processor card. After all, I'm a de- cent, intelligent, honest person. 1 teach my children the value of personal in- tegrity, and I pride myself on my honesty. I never keep overpayments. I pay my taxes. I even spent over six months convincing a large department store that I owed it money when it couldn't find any record of the transac- tion. I don't allow my children to make audio-tape copies of records for each other. After ten years in the entertain- ment industry, I know how valuable a copyright is to a performer. So, how did I become a software thief? It started when I sold my Altair Tarbell cassette machine and upgraded to a North Star disk-based system. I knew when I got the system from a friend that he had piles of software to supply in the deal. That was the main reason I worked with him— to get the software. There were about twenty disks full of BASIC games, business programs, and a word processor. A neat little assembler and disassembler were included, although my primary interests were word processing and BASIC. I rationalized it this way: I would never do any commercial work using any of the programs. I was just learning—sort of "test driving. " If I did decide to do any serious programming, I would purchase what I needed to keep everything legal. I was, after all, an honest man. It worked too well and for too long. It wasn't very long before I had forgotten my commitment; moreover, I wasn't doing any serious work on my computer. I did buy an updated ver- sion of North Star BASIC from the fac- tory, which sort of made me legiti- mate. Things were stable for about a year, with no exchanging or sharing. Then, I had a letter published in a magazine where I casually mentioned I would be interested in exchanging pro- grams. Before I knew it, I had a grow- ing file of others interested in "sharing" what they had. This list eventually focused on an individual in Michigan who seemed very generous and quite sincere in helping me not only get soft- ware, but in getting it up and running. Over a three-month period this rela- tionship blossomed into a friendship. I was very grateful to this person. I was doing most of the receiving and only minimal giving, but he didn't seem to mind. There are people who get plea- sure out of helping others. I was about to submit a software review to a magazine when I was con- fronted with the stark truth: I was a thief. I don't know if the fear of being found out is what motivated me to take a long, serious look at my past ac- tions. But whatever it was, I was faced with three problems: • I had received stolen goods. • I required these stolen goods every time I turned on my computer. This meant that if I decided to change my position, I would have to purchase a license and become a legitimate user of several hundred dollars' worth of pro- grams. • The explanation I would have to give to my Michigan buddy. How could I take his generosity and tell him that, for me, it had become criminal? I prepared a letter, and, as fate would have it, he called me while it was in the mail. I had to tell him what I had spent so much time carefully wording. I felt trapped. Finally, I began to unfold how I felt about ex- changing software. I explained that mine was a unilateral decision and wasn't meant to push him into a similar repentant attitude. It was wrong for me but not necessarily everybody. The words came out, and he seemed to take it very well and understand my position. It was several months before I heard from him again. When I did, he wasn't very friendly. It was an impossible situation. This is the number one problem in stealing software: You cannot do it alone. Someone knows you will com- promise your values if the price is right. Maybe even worse, you know you are helping other people com- promise their values. During this particularly difficult time for me, I remembered something my dad had told me when I was a boy. We had just left a friend's ranch after hearing how he had been paid for two cases of eggs he never delivered. My dad said, "If a man will cheat somebody else, he will cheat you. " Text box continued on page 24 22 September 1981 © BYTE Publications Inc We designed them to meet two standards. Ours. And the industry's. With a Toshiba Very Small Business Computer or Word Processor, you'll never worry about obsolescence and reliability That's because they're designed to meet not only the industry's software and operating standards, but our own high standards of quality and dependability. With Toshiba, you can rest assured knowing you'll get day- in, day-out dependability built Word Processor right in. We build most of the components ourselves . . . which gives us complete control over quality, reliability, and performance every step of the way. And Toshiba now offers you a fully developed and comprehen- sive dealer program based on our high standards of quality, reliability, and deliverability. Which means you can build your product line . . . and your profits. So when you're looking for a reliable, well-thought-out VSBC or Word Processor, remember the name Toshiba. Our standards are as high as yours. EW-100 display capacity; 80 characters x 24 lines floppy disk: 8" storage capacity: 300KB x 2, 1MBX2 type of printer: daisy-wheel printer printing speed: 45 characters/sec. print pitch: 10/12/proportional spacing ■ ines T200/T250 Hardware memory: 64KB display capacity: 80 characters x 24 floppydisk:T200:5'/4" T250: 8" storage capacity: T200: 280KB x 2 T250: 1MBX2 printing speed: 125 characters/sec. characters per line: 136 characters Software CP/M®, Microsoft BASIC-80, CBASIC CP/M* is a registered trademark of Digital Research, Inc. CBASIC is a trademark of Compiler Systems. Inc. Please send me more information about Toshiba's Word Processor and VSBC: D Products □ Dealer Program City -Zip Phone Information Processing Systems Division TOSHIBA AMERICA, INC. 2441 Michelle Drive, Tustin, CA 92680 Tel: (714) 730-5000 Circle 362 on inquiry card. BYTE September 1981 23 Letter* cannot be depended on in all situations. The most reliable and useful software that I have purchased runs under a standard operating system and is easily modifiable by means of a configuration program or a copy of the source code. More than once, I have decided not to purchase a desirable software product when I became aware that it did not sup- port our system configuration and was packaged in a copy-protected form. Sure- ly the revenue lost to vendors in this man- ner is as significant as that lost to "pirates." Our firm plans to enter the small-com- puter-software market through direct and retail sales. BYTE readers should be as- sured that our programs will be fully ac- cessible, modifiable, and packaged with source code whenever feasible. Yes — we'll be vulnerable to piracy. But I believe that the solution to the software- piracy problem is increased vendor sup- port (rendering pirated copies less valu- able) and vigilant enforcement of protec- tive laws, not making software products less accessible to the user. Michael C Berch Managing Partner Southside Systems 2424 Haste St Suite A-40 Berkeley CA 94704 I would like to comment on the May 1981 BYTE editorial and the two articles on the subject of software piracy. There are two sides of every fence. BYTE took the side of the software provider; let me take the side of the user. I purchased an Apple II, disk drives, video monitor, printer, modem, etc, plus about $1000 worth of software for busi- ness use. This is not my hobby, and I have no intention of becoming any more of an expert with computers than I must to achieve my purpose. From my standpoint, the price of all of this stuff is so low that there is absolutely no point in messing around either with pi- rates or in doing it myself. Even the book- keeping and inventory-control programs, at $600 to $1000 or more, pay for them- selves in a few months. If the minicomput- er manufacturers could ever get their act together, the business-software market would dwarf their present endeavors. (I think that the Japanese will do the job for them, and Apple will wind up back in the old garage along with the others.) Text box continued: There is no sacred bond above which all transactions are honest and below which honesty is negotiated. I sent away for the software I re- quired to keep writing. As luck would have it, I had been legitimately given two key pieces of software, that were mine to keep, in return for providing reviews to magazines. So as it turned out, 1 had won and I had lost. Cleaning up my act didn't cost me as much as I thought it would; however, I lost a friend. I consider that loss the highest price to pay for my transgression. I'm sure there are those who will be critical and demand I pay for the soft- ware I used for the two years. All I can say is that I've given it careful thought and I feel comfortable with my current situation. Foolproof, protected software is fic- tion and will never be reality because it has nothing to do with technology. It has to do with the human condition. There always will be people who will compromise integrity for material gain. And there will be those, like myself, who will slip past honesty and into what they often call a "gray area" before they get their heads out of the sand and take responsibility for their actions. And, thank God, there are a handful whose integrity will not waiver. As long as this human condi- tion exists, there will be no perfect system for software protection. There are, perhaps, only two reasons for maintaining personal in- tegrity. One is the fear of being discovered and exposed — or worse, punished. An idea I read a year or so ago suggested that a bounty on pirates may be the most workable tool to en- force this first reason. I don't like this idea: there are too many holes in it. But it does seem the most effective way to put the fear of being caught into pirating. On the other hand, there is the moral fiber within each of us that merely needs to be awakened to be- come strong and effective. Careful ex- amination of your situation with a critical eye on what you know to be right and wrong will certainly expose any deficiencies. It then becomes a matter of pricing your integrity and remembering that you can't steal soft- ware by yourself. Yes, the process of evaluating the circumstances is simple. The difficulty of implementation will likely be directly proportional to how deeply involved you are in stealing. Drop me a postcard — anonymously, if you prefer— and let me know your feelings. Eugene Dorman c/o BYTE Publications Inc POB 372 Hancock NH 03449 I have two Apple programs that pro- vide access to the Dow Jones data base for the purpose of obtaining securities quotes, keeping track of portfolios, and the like. One program is written in BASIC, is user- accessible and, with some user modifica- tions, works like a charm. The other pro- gram is "locked." It doesn't work. Apple has a disclaimer in its program manuals absolving them of all respon- sibility. So far, Apple hasn't abandoned me, but it's taking its own sweet time about coming up with a fix. When and if a fix comes through, no field modification by the user will be possible. I have a pret- ty good idea what the problem is and if I could gain access to the program, I could probably fix it myself in a short time. This way it will take weeks or months, if it gets fixed at all. I think the denouement is that a determined and knowledgeable pirate will succeed no matter what, while the honest and legitimate user, like me, takes it on the chin. Adolph L Friedman POB 2856 Santa Fe NM 87501 I disagree with Chris Morgan's editorial on software piracy. It seems that the soft- ware expert has a stranglehold on the per- sonal computer. His hand is clutched around my wallet and he is squeezing for all it is worth. I don't like that. In the capitalistic system, competition brings the price in line. Software is a monopoly, and Mr Morgan's concern is like government- secured loans to Chrysler. Why not let the software people pro- vide more flexibility to the user7 If the software is easier to obtain and more reasonably priced, a larger number of people would own personal computers. 24 September 1981 © BYTE Publications Inc Most small system users think all micro- computers are created equal. And they're right. If you want performance, convenience, styling, high technology and reliability (and who doesn't?) your micro usually has a price tag that looks more like a mini. It seems big performance always means big bucks. But not 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 to 10 megabytes. A full 64K of dynamic RAM. A CP/M* Disk Operating System to insure 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. f= INTE3TEC Cdata s systems, 2300 Broad River Rd. Columbia, SC 29210 (803) 798-9100 TWX: 810-666-2115 Circle 193 on inquiry card. TM ■«■■■ &Mi !**, 1 ill Jill J fill, III ■ 111 1 1 25W .:. INTE5IK: DATA SYSItMS 1 j . . i. T i ■ etteri That in itself would increase the market for software. The broader the base of peo- ple using computers, the greater the varia- tions and the need for software. What Mr Morgan proposes is like Ex- xon buying up the "good gas-mileage car- buretors" before they get to market. It sounds to me that Mr Morgan is trying to protect the pirates. Brigg Leurs 436 N 1050 E Kaysville UT 84037 It seems to me that the solution to soft- ware piracy has been evident and used for a considerable time by BYTE's parent company, McGraw-Hill. Hundreds of man-hours can be used in the writing and debugging of a program, and this can be translated into cost and selling price, the same as any other commodity. The Osborne Accounting System, for example, has a finite value. The disks for each program are available at a very low price, even as low as $8, from one of BYTE's advertisers. However, the com- prehensive and beautifully published manuals that include the source code can be purchased for $20. You could not photostat one of these manuals for less than this price. Therefore, you buy it. It would be interesting to know how many manuals the McGraw-Hill Book Company has sold and what the income has been, per program. I'm sure this shows one solution: give the disk away and sell the manuals, like the old stunt of giving the razor away, but selling the blades. All of the methods for "locking in" programs and "locking out" software pirates are rather foolish. Everyone knows that you can access every byte on every track, change the ID and password, disassemble, and transfer from one system to another. A A Schwartz 6454 EI Camino Del Teatro La Jolla CA 92037 The antipiracy devices mentioned in Chris Morgan's editorial are quite in- genious, but like all human inventions, they are fallible. I wonder if BYTE readers would like to reconsider the whole ques- tion of "software protectionism" at a more elementary level. I can identify at least three basic "in- stincts" at work which must be accommo- dated: • the natural inquisitiveness of the human mind • the insatiable attraction of acquiring things for oneself • and the irresistible challenge of another human mind Inasmuch as knowledge and informa- tion are the essential contents of all soft- ware, to keep them "locked away" is old- fashioned logic. Widely disseminated knowledge will bring forth more knowl- edge. In an age when knowledge becomes rapidly outdated, hanging on to some lit- tle invention is unrealistic. Like all at- tempts at prohibition, the setting up of barriers is probably the most potent stimulus to overcome them. Such at- tempts have only resulted in the escalation of costs to the consumer, the production of weird and delicate formats that are much more prone to crashes, and the great step backward of adding un- necessary keys and ROMs (read-only memories) that defeat the advantage of computerization. Is it too late to take a 180° turn and stop this "cold war" from escalating? Would it be possible to take the alternate view7 Here are some suggestions: • The ultimate way of getting rid of piracy is to make the purchase of genuine soft- ware so cheap that it becomes uneconom- ical to copy. Who bothers photocopying paperback books? The volume of sales will more than compensate for the lower- ing of the profit margin and protection costs. • Software houses should encourage users to become subscribing members. This would provide capital for software devel- opment as well as some degree of customi- zation of the software to be developed. New programs could be offered to sub- scribers on a priority discount basis. • Users clubs should be encouraged to adopt a code of ethics; in ieturn they would be allowed to participate in a scheme of evaluation and bulk ordering of new products. There is no pressure greater than peer pressure. • A good user and upgrading service should be arranged so that a firm bond is created between the user and the software producer. Newsletters with user com- ments is one way to achieve this. I am glad to say that at least one soft- ware company, Personal Software, has begun to adopt this new attitude for its Data Management System and Desktop Plan. I salute them. I sincerely hope that BYTE and its readers will take the initia- tive of spearheading this more rational ap- proach before you have to say "open sesame" to your computer. Dr A Hua Department of Medicine Queen Mary Hospital University of Hong Kong Hong Kong Letters continued on page 30 IEEE 488 TO S-100 INTERFACE Handles all IEEE-488 1975/78 functions EEE 696 (S-100) compatible MBASIC subroutines supplied; no BIOS mods required 3 parallel ports (8255A-5) Industrial quality; burned in and tested (Dealer inquiries invitedl D&W DIGITAL 1524 REDWOOD DRIVE LOS ALTOS, CA 94022 14151 966-1460 26 September 1981 © BYTE Publications Inc Circle 99 on inquiry card. Circle 372 on inquiry card. BROADEN YOUR HORIZONS .A^^MlAta UVEON proudly announces OPTIMUM:" OPTIMUM is an easy to use, total concept data management program for CP/M® and MP/M M systems. Breaking through traditional DMS barriers, OPTIMUM provides large scale data management capability to broaden your computer horizons. Developed for individual computer users and applica- tions builders, OPTIMUM supports user-defined forms and files, dictionaries, powerful reporting, storage efficiency, speed and unique cross-referencing. r .L! ;_ J_ - * , ..ow complete in one system. USER-DEFINED FORMS AND FILES With OPTIMUM, implementing an application is simple. The user defines screen forms to fit the data and describes how the data is to be stored. Once this is complete, data entry may begin. Input editing, validation and cross-referencing during data entry extend OPTIMUM'S range. If the need exists, OPTIMUM can handle complex or multiple screen forms for the same file. Screen forms may be modified and expanded as needed. DICTIONARIES OPTIMUM maintains a dictionary of terms for each file. This dictionary contains information on each data element in the file and describes operations to be performed. Alterations and additions to the dictionary may be made as required. MICRO-ENGLISH IM REPORTING OPTIMUM Micro-ENGLISH lets the user request standard or custom reports from the OPTIMUM files. Sophisticated selecting and sorting capability give Micro-ENGLISH all the power of a large scale interactive inquiry processor. A dictionary based vocabulary keeps the user interface simple. OPTIMUM STORAGE EFFICIENCY AND SPEED OPTIMUM stores all information in a compact variable-length format. OPTIMUM files are designed for interactive speed; a single file item may be retrieved from among hundreds in an instant. OPTIMUM DATA CROSS-REFERENCING A unique feature of the OPTIMUM system allows a user to cross-reference data elements. Once information is entered, it may be retrieved using key words in the data. From simple applications to complex systems, OPTIMUM manages it all. Broaden your horizons using the total concept data management system with the power of such industry forerunners as Prime Information, Honeywell Ultimate and Microdata Reality. Call or write UVEON today for more information on OPTIMUM. 1-800-525-1637. CP/M and MP/M arc trademarks ol Digital Research, Inc. OIT1MUM and Micro ■ENGLISH arc trademarks of UVEON Cumputcr Systems, Inc. uveon The Future in Software. UVEON Computer Systems, Inc. 899 Logan Street Denver, Colorado 80203 r . ■ ■■ ■ ■ . ■ " ' ■ ■ . - ■ ■ • ■ - ,: .. , ■ ■ ■ '■ ■'■■'. A Major Breakthrough The The System 2800 is the next logical step in the continuing line of innovative products from the Systems Group. Unbeatable S-100 Memory Boards First was the development of the DMB6400 series of S-100 Memory boards featuring the innovative Bank Select switching technique. This enables users to software select up to four totally independent memory banks per board. The 2nd Generation Then came the 2nd Generation of IEEE S-100 COMPATIBLE Z80 PROCESSORS, FLOPPY DISK CONTROLLERS and SERIAL I/O BOARDS. Each has been designed for single user, multi-user or network operating syst such as CP/M®, MP/M™, CP/Net™ and OASIS™. The Next Logical Step ... We challenged our design team to create an innovative yet competitive system utilizing our existing line of field proven, dependable S-100 boards. The result: a highly reliable, quality built, state of the art microcomputer that gives you the cost/performance edge you need to be a leader in your field. The System 2800 comes with a choice of operating systems: CP/M with an enhanced CBIOS for single user systems and either MP/M or OASIS for multi-user, multi-tasking systems. MP/M is available with either a standard or CP/M MP/M and CP/Nat are trademarks of Digital Research OASIS is a trademark of Phase One Systems ■ * =1 enhanced XIOS. The CP/M based System 2800 provides improved diagnostic reporting capability and increased sector sizes of 1024 bytes yielding disk performance throughput increases up to 400% over standard unblocked systems. The enhanced multi-user, multi-tasking MP/M based System 2800 provides the same advanced features as CP/M. In addition, this interrupt driven implementation can offer performance throughput increases up to 2000% thru extensive disk buffering for applications requiring a large number of disk accesses. Also available is the OASIS operating system with ISAM files, automatic record locking and multiple-user print spooling. All operating systems are available in either floppy or hard disk configurations. The disk drive selection includes single or double sided, double density 8-inch floppies with up to 2.52 megabytes of formatted storage per system, expandable to 5.04 megabytes, and an 8-inch 10 megabyte Winchester hard disk. Cost Effective Reliability Dealers, OEM's and System Integrators share many common needs. Not the least of these is dependable products. That's why we back our System 2800 with our established reputation for high quality products, superior support, prompt and courteous service, and a one-year warranty. Take the next logical step. See your nearest computer dealer, or contact us for the complete story on our S-100 family of board products and enhanced systems. Systems Group a Division of MEASUREMENT systems &. controls incorporated 1601 Orangewood Ave. Orange, Calif. USA 92668 (714) 633-4460 TWX/TELEX: 678 401 TAB IRIN For International Sales Inquiries contact: SIGMA INTERNATIONAL, INC., P.O. Box 1118, Scottsdale, AZ 85252 USA (602) 994-3435 / Telex 165 745 Sigma Circle 210 on inquiry card. SITTING PRETTY You can use just about any desk for a computer ter- minal stand. But with CF&A, you're sitting pretty. Our full range of desks, workstations, and terminal stands are designed to accommodate a variety of computer equipment. Choose from our Cfassic Series desks, DR Series desks and enclosures, spe- cialty items like our Apple II desk, or a universal printer stand. You'll be sitting pretty with attractive color selections, durable construction, versatile configurations, useful options, competitive prices, quick delivery, and personal service. It's our way of doing business. CFA Computer Furniture and Accessories, Inc. 1441 West 132nd Street Gardena, CA 90249 (213)327-7710 Letters, The Wind Blowest Where It Llsteth Something is a bit strange about BYTE's May 1981 cover. The sail is full and set for a run (which means wind astern), the burgee points to port (which means wind off the starboard), and the spray from the bow wave points to starboard (which means wind to port). I've seen things like this on a lake just leeward of an island, but only for a moment. It's pretty unlikely on the open sea. And, worst of all, the sail has a big hole in itl BYTE's cover has inspired a new disparaging remark about a landlubber: he doesn't know his sail from a floppy disk. John A Ball Oak Hill Rd Harvard MA 01451 The May cover is a faithful representa- tion of a situation that occurred during the BYTE staff's last outing. By the way, we know about floppy disks, but what's a "sail"? . . . CPF Programming As an Essay As a programmer whose background is in literature, I am naturally sympathetic to the analogy between programming and natural languages that John Handel draws in his article 'The New Literacy: Pro- gramming Languages as Languages." (See the March 1981 BYTE, page 300.) That a programming language is indeed called a language, that programming borrows much of its lingual terminology from natural languages (eg: word, paragraph, syntax), offers at least a hint of the parallel that Mr Handel persuasively develops. At one point, however, he makes an analogy between a program and a book that I find a bit contrived. His argument would be better served with an analogy between a program and a formal essay. Having written both, I find the thought processes involved in both remarkably similar. Essentially, a formal essay consists of a thesis, arguments to support that thesis, and a conclusion. Its usual purpose is to interpret, persuade, or inform: to solve some critical or rhetorical problem. Before writing can begin, an essayist must be able to express clearly to him- or herself the thesis and conclusion in order to define 30 September 1981 © BYTE Publications Inc Circle 75 on inquiry card. Please call (213) 883-8594. Our Epson prices are so low, we're not allowed to print them. EPSON MX-80 SCALL 80 cps/9x9 matrix/Lower case with true descenders/Bi-directional & Logic seeking/Adjustable tractor/ Expanded printing/Block graphics/ Forms control/Compressed printing/ Double-strike printing/Correspon- dence quality/Emphasized printing mode/Standard parallel interface EPSON MX-80 F/T SCALL Same features as the MX-80 plus Fric- tion Feed. Adjustable removable trac- tor is standard for ease of handling forms and single sheets. EPSON MX-100 F/T SCALL Same features as the MX-80 & MX-80 F/T but on 1 5 1 /2 inch carriage for print- ing 132 columns with standard 10 cpi font or 232 columns in the com- pressed character font. The MX-1 00 is complete with Dot Resolution Graphics EPSON INTERFACES & OPTIONS TRS-BO MODEL I, III CABLE TRS-80 MODEL I Keyboard Interface TRS-80 MODEL II CABLE .$ 30 $ 95 .$ 30 APPLE INTERFACE & CABLE ... . .$ 100 IEEE 488 INTERFACE SERIAL INTERFACE 60 70 SERIAL INTERFACE (2K BUFFER) $ 149 SERIAL CABLE Male to Male S 30 DOT RESOLUTION GRAPHICS $ 90 REPLACEMENT RIBBON $ 13 REPLACEMENT PRINT HEAD (Quiet type) .$ 40 EPSON SERVICE MANUAL $ 40 We built a reputation on our prices and your satisfaction. We guarantee everything we sell for 30 days. If anything is wrong, just return the item and we'll make it right. And. of course, we'll pay the shipping charges. We accept Visa and Master Card on all orders. COO accepted up to $300.00. We also accept school pur- chase orders. Please add $2.00 for standard UPS shipping and handling on orders under 50 pounds, delivered in the continental U.S. Call us for shipping charges on items that weigh more than 50 pounds. Foreign, FP0 and AP0 orders please add 15% tor shipping. California res- idents add 6% sales tax. 31245 La Baya Drive, Westlake Village, California 91362 Circle 13 on Inquiry card. ■ Bttmrw the problem, its scope, and to provide a framework for its solution. Similarly, a programmer must have a definition of his or her problem, and he or she must be able to frame a solution before coding can begin. Both the essayist and the program- mer must know where they want to go before they can begin the detailed work to get there. Next, the essayist must gather his or her major arguments and break the thesis into components, just as a programmer will break the problem into manageable parts. A writer will then arrange the arguments so that they flow smoothly through the essay. A programmer will begin arranging the parts of the problem so that they operate in an orderly fashion. Finally, the detail work can begin. A writer will supply minor arguments and examples to "flesh out" his or her work. A programmer at this point concentrates on code. Both will polish their work, en- suring that grammar, diction, and syntax are correct. An essay may not have to communicate "in a precise fashion" and an essayist must rely on a reader to "test" the thesis (not as strict a standard as a programmer's com- puter), but an essay must communicate in l# I- GRAPHICS 512x240 RESOLUTION Z-89 & Superbrain And soon for TRS 80 MODEL II XCEL GRAPHICS UNIT — A completely assembled hardware retrofit package providing high resolution graphics display, normal video display or both displays simultaneously. $895.00 $175.00 XCEL™ SYMBOL GENERATOR-Subroulmes 10 generate characters and sitings with bold lace, and 90" rotation options, circles, arcs. veciors. reciangles. area tills with reverse video option All callable Irorn your programs < $175.00 GRAPH PLOTTER-Crioice ol lour ropresen- lalions (line, graph, histogram, bar graph ana scatter plot) wilh automatic annotation ot axes and automatic scaling Ihat allows any number ot functions to be displayed on ono set ol axes All callable from your programs ^> $345.00 It-Y,-, '*--. -IS XCEL™ 3-D GENERATOR— User accessible rou- tines lor creation, editing and viewing "wire- frame" objecls Irom any angle and in any orientation wilh scaling "zoom" and a graphics editor < $395.00 XCEL™ SURFACE PLOTTER-Tiue pci spfjclivc view, with lull hidden line removal, of curved surlaces Irom a user defined viewpoint callable from yeur programs ^> $395.00 XCEL™ GRAPHICS TERMINAL— Emulates a subset ot the Tektronix® 4010 Series Graphics Terminal lunations Simple menu-driven key- board commands for configuration and dot- dash and erase mode vectors. XCEL™ software packages operate under CPM® and utilize the Microsoft parameter passing mechanism tor compatibility with high level languages, such as BASIC. FORTRAN, COBOL, PL1 , and PASCAL. XCEL software can be loaded into high memory and called from your programs or integrated direclly into your programs through use of the Microsoft linking loader. (800) 421-1423 FOR ADDITONAL PRODUCT INFORMATION IN CONTINENTAL U.S. CALL TOLL FREE: IN CALIFORNIA CALL ^ / ^ (213) 320-6604 ^5^^.MAXTEK,IISIC 2908 Oregon Court, Torrance, CA 90503 Tektronix* is a registered trademark ot Teklronik, Inc CPM« is a registered trademark ul Digital Research 32 September 1981 © BYTE Publications Inc Circle 207 on inquiry card. a reasoned and orderly fashion. Both writer and programmer must be logical within a verbal framework. I agree with Mr Handel's conclusion that a programmer with verbal sensibility will tend to write readable programs that work. Perhaps then, programming in- stallations, especially commercial shops where the work is not technical or mathe- matical, may do well to employ language and linguistic students. Perhaps too, a source of programming talent may be found in writers and students of philo- sophy and history who already have a command of language and procedural skill and who could learn the particulars of programming quickly and easily. Michael J Nichols 1725 York Ave New York NY 10028 Vikings Defense It may be that BYTE's attention some- how has been focused on the aspects of violence in the history of the Vikings. The cover on the May 1981 BYTE and the text on page 4 does, however, indicate that BYTE ought to read up on the Vikings as well as on their contemporary history. BYTE has done the Vikings a gross in- justice by merely stating that they were "notorious pirates." Let me say in their defense that they were also clever sailors, innovative navigators, explorers, and tradesmen, who traveled routes that to- day seem impossible considering the equipment they had at hand. They were tough, maybe, and violent — living in times of different general ethics and values than you may wish for yourself today. But, to call them pirates, with an indica- tion of lawlessness, is simply an (unfair) application of current values to a very dif- ferent time and place. The Vikings also were clever ship- builders, building perhaps the most beautiful boats that have ever been made. You may see some of these here in Oslo and judge for yourself. F.inar Skjorten Rytterfaret 21 1347 Hosle, Norway We apologize, Mr Skjorten, for our somewhat simplistic representation of the Vikings. . . . CMi Circle 272 on inquiry card. The guy on the left doesn't stand a chance. The guy on the left has two file folders, a news maga- zine, and a sandwich. The guy on the right has the OSBORNE 1®, a fully functional computer system in a portable package the size of a briefcase. Also in the case are the equivalent of over 1600 typed pages, stored on floppy diskettes. The owner of the OSBORNE 1 is going to get more work done — and better work done — in less time, and with less effort. Unfold it, plug it in, and go to work like you've never worked before. . . . Go to work with WORDSTAR® word processing, so your correspondence, reports, and memos take less time to produce, and say more of what you wanted to say. And with MAILMERGE® — the mailing system that turns out personalized mass mailings in the time you'd spend on a rough draft. Go to work with SUPERCALC®, the electronic spreadsheet package that handles complex projections, financial planning, statistics, and "what if" questions in- stantly. For the more technically minded, SUPERCALC will process scientific data and calculate results. Go to work with powerful BASIC language tools — the CBASIC-2® business BASIC, or the Microsoft BASIC® interpreter. That's standard equipment. Options include about a thousand different software packages from a host of vendors designed to run on the CP/M® computer system. Go to work at the office, at home, or in the field. Or anywhere. Optional battery packs and telephone transmission couplers mean you need never work without the capabilities of the OSBORNE 1 . That's good, because you won't want to work again without it. All for $1795. It's inevitable. The OSBORNE 1 is the productivity machine that's changing the way people work. Put simply, the machine delivers a significant productivity edge— day in and day out — to virtually anyone who deals with words or num- bers. Or both. Since the entire system is only $1795, it won't be too long before the guy on the left has an OSBORNE 1 of his own. The same probably goes for the person reading this ad. In fact, we think it's inevitable. The OSBORNE 1 includes a Z80A®CPU, 64K bytes of RAM memory, two 100 kilobyte floppy disk drives, a business keyboard, built-in monitor, IEEE 488 and RS232 inter- faces for printers and other things that get connected to computers, plus CP/M, CBASIC-2, Microsoft BASIC, WORDSTAR, and SUPERCALC. The system is available from com- puter retailers nationally. $1795. It's inevitable. COMPUTER CORPORATION 26500 Corporate Avenue Hayward, California 94545 Phone (415) 887-8080 TWX (910) 383-2021 Book Reviews Principles of Artificial Intelligence Nils J Nilsson Tioga Publishing, 1980 476 pages, hardcover S27.50 Reviewed by Steven K Roberts and James Paul Jenal 5885 Dublin Rd Dublin OH 43017 Artificial intelligence (AI), for over two decades the ar- cane province of academic visionaries, is at last spilling over into the worlds of engi- neering and practical system design. A fascination with the programming language LISP is sweeping the industry, ro- botics and machine vision (though still primitive) are something other than fan- tasy, and the cost of com- puter hardware on a scale necessary for AI work has dropped to the point where it even touches the personal computer spectrum. It is becoming worthwhile to learn something about the subject for reasons beyond intellectual curiosity. A new book by Nils J Nilsson offers a substantive look at a body of techniques upon which much of the work in the artificial intelli- gence field is based. Presently the director of the Artificial Intelligence Center of Stan- ford Research Institute, Nilsson has for years been in- volved in problem-solving, theorem-proving, and plan- ning systems, and has authored publications along these lines that date back to the early 1960s. Principles of Artificial In- telligence is intended as a text for a college senior or first- year graduate student, and can thus be considered to be the reader's first serious ex- posure to the field. But a question arises as to whether or not the ensuing (fairly rig- orous) discussion of predicate calculus is the way to pro- ceed. Though the text was written as an introduction and does, in fact, concern it- self far more with underlying techniques than with applica- tions areas, it focuses fairly strongly upon formalisms with which the reader new to the field might be a little un- comfortable. Predicate calculus is cer- tainly not new to serious stu- dents of computer science — it is required material in almost any undergraduate com- puter-science curriculum, though exposure is typically limited to formal proving ex- ercises. Nevertheless, predicate calculus does pro- vide a refined set of manipulative tools that are useful for the implementation of knowledge-based pro- duction systems, and it has a distinct advantage over some of the more intuitive para- digms, such as relational databases and semantic net- works, in that it has matured from many years of disci- plined development in other application areas. Though imposing in appearance, it is a reliable basis for system de- sign and, thanks to its univer- sal acceptance, for communi- cation of ideas with other workers in the field. However, one of the ideals of artificial intelligence work is the comfortable bridging of the vast conceptual gap be- tween man and machine. Al- though this inevitably re- quires the application of for- mal tools, it should even- tually lead to increased "naturalness" of problem ex- pression. In a purely rigorous sense, any Turing machine implementation is as good as another (they provide the same computing power), but the differences to those who must use them are significant. As anyone who has ever at- tempted to express abstract, symbolic constructs within the syntactical and semantic restrictions of FORTRAN knows only too well, the issue of naturalness is inex- orably tied to the representa- tion problem. Early on, Nilsson states that "selecting a good repre- sentation is one of the impor- tant arts involved in applying AI techniques to practical problems." This is indeed true, not only in this field but in all aspects of computer problem solving. Knowledge representation, whether via a body of production rules (if... then constructs), frames (relatively passive data en- tities appropriately intercon- nected and applied to a set of inference procedures), or any other means, is a central and hotly contested issue that af- fects not only the usefulness of a system's design but its naturalness. While different approaches may not neces- sarily provide greater power, they might free the mind to achieve greater insights — and insight is at the heart of all problem solving. Nilsson makes a good case for the use of predicate cal- culus as the set of "cranks" with which any type of sys- tem can be implemented. Whether or not this approach constitutes an optimal entry into the artificial intelligence field is partly a function of the reader. From a classical engineering standpoint, the assimilation of formal methods before exposure to the more philosophical aspects is absolutely neces- sary, and for those who are comfortable with this ap- proach, the book comes highly recommended: the problems are interesting, yet not so esoteric that you lose sight of their purpose — name- ly, the chance to apply the principles that Nilsson has so painstakingly laid out. Those who lack the text's presup- posed ease with formal methods (and there is much of interest in the field that does not require it) might prefer a book targeted to an overview of AI's various sub- specialties (such as Patrick H Winston's classic, Artificial Intelligence , Philip C Jackson's Introduction to Artificial Intelligence, or Pamela McCorduck's Mach- ines Who Think). Principles of Artificial In- telligence, like its pre- decessor, Problem-Solving Methods in Artificial Intelli- gence (Nilsson, McGraw- Hill, 1971), can be considered an authoritative text on many of the underlying ideas that serve as the basis for the bulk of current artificial intelli- gence research. After Nilsson develops the primary theme, he provides a number of pro- vocative comments about the field, and closes with a com- prehensive and up-to-date bibliography of published works. Though hardly casual reading, the book offers solid underpinnings for method- ologies which might other- wise appear disquietingly magical. ■ 34 September 1981 © BYTE Publications Inc Circle 312 on inquiry card. —*■ Radio Shacks TRS-80 Model III is Your Best Buy in Desktop Computers 2495 Because You Get Last Year's 32K Price! That's right, we've added 16K more mem- ory, but kept the price at a low $2495! The TRS-80 Model III is a complete, ready-to- run desktop computer packed with "extras" that don't cost extra: Two Double-Density Disk Drives. You get two built-in 175K disk drives, and can add up to two more externally. BASIC in 14K ROM. Our powerful Model III BASIC provides a program line editor, machine language programming, real time clock, and more. Compatible with most Model 1 Level II BASIC programs, too. Plus, you can expand with COBOL or Compiler BASIC any time. Upper and Lower Case Characters. With a special graphics character set, and 64 characters-per-line format. Built-in Monitor. 121' high-resolution. 12-Key Datapad. As well as repeating keys and keyboard-controlled screen print. Parallel Printer Port. Add one of our print- ers anytime. RS-232 Serial Interface. For data commu- nications, just add a modem. Nationwide Support. Backed by 6100 Radio Shack stores and dealers, 160 Com- puter Centers and 160 service centers throughout the USA Available Now. Why pay more? Get a demonstration today. Also check out our $999 16K Model III- system. -it's a perfect "starter" Radio /hack The biggest name in little computers ' A DIVISION OF TANDY CORPORATION Read about your best buy in com- puters. Send for a TRS-80 catalog. Radio Shack, Oept. 82-A-122 1300 One Tandy Center Fort Worth, Texas 76102 Retail prices may vary at individual stores and dealers Special order may be required. NAME I STREET | CITY STATE L Z,P . PHONE A LOOK AT NCC 01 by Steven K Roberts, 5885 Dublin Rd, Dublin OH 43017 This year's National Computer Conference, held last May 4 through 7 at McCormick Place in Chicago, was so large that nobody could effectively see all of the show in the four days allotted to it. In fact, with about 73,000 people attending, it was often difficult to see the displays at all. The task was also complicated by the juxtaposition of booths for every type of com- puter, from microcomputer to mainframe, and their associated supplies and peripherals. Still, what I did see was ex- citing; shown here are some of the attractions. 36 September 1981 © BYTE Publications Inc a a y ig ii dd a ta y h IIBBBDBDIII ■ r« ■ * B v B °|jnJ mJ : 17.1 185 no sound 3F STOP ? 47 no sound Note: T must precede CH to produce "CH" sound. D must precede J to produce 'J" sound. Table 1: The sixty-four phonemes defined for the English language Two of these produce silence; one causes synthesis to cease. dedicated memory buffer. Typically a 32- or 64-character FIFO (first-in, first-out) buffer is attached to the computer bus and loaded with the phoneme codes under program con- trol. Once loaded, the codes are shifted out one at a time as the STB and A/R lines change states. This self-clocking technique can also be used with an EPROM (erasable programmable read-only memory) and a counter when the SC-01 is to speak a canned message without computer control. While use of a FIFO buffer reduces the main processor's waiting time when exercising relatively slow (typi- cally 70 bps) peripheral devices such as the SC-01, buffers are expensive. Interface-hardware costs can be measurably reduced by a second scheme: using the computer system (running an appropriate program) to time the transmission of phoneme codes to the SC-01, as outlined in figure 3b. This method sends codes to the synthesizer chip through a latched parallel output port and monitors the synthesizer's activities (via the A/R line) through an input port or inter- rupt line. The latter is the technique I chose to use in my design. Interestingly enough, eliminating the extra hard- ware doesn't really complicate com- puter/synthesizer interaction nor does it require a sophisticated ma- chine-language driver program like those ordinarily associated with soft- ware-controlled peripheral devices. The program code to control the syn- thesizer can be as simple as an LPRINT statement in BASIC. More on this later. Sweet Talker The schematic diagram of the Sweet Talker speech-synthesizer cir- cuit board is shown in figure 4 on page 44. The phoneme-code bits are sent in parallel to the SC-01 (IC3) and buffered through ICl (a 74LS244 three-state octal buffer). Pull-up resistors assure that a logic-1 input to the SC-01 will be at least 4 V as re- quired. Unless the board is being used with external address circuitry, the Enable input line (on connector Jl, 42 September 1981 © BYTE Publications Inc (3a) WRITE v SC-01 P0-P5 11, 12 STB A/R IN SHIFT IN Fl FO SHIFT OUT OUT try + O NCON V O wo— 4 L. NOTE: THIS PULSE EXTENDER IS REQUIRED ONLY IF DATA STROBE IS LESS THAN 100 MICROSECONDS LONG. +5V AND +12V POWER SUPPLY H% ._! Figure 5: Diagram of the connections between a Centronics-compatible parallel printer port (as on a TRS-8 Model 1 or III) and the Sweet Talker circuit board. Note that on some computers the Unit Select line may need to be connected to +5 V. plifier and filter sections. Capacitors Cl and C2 and resistors R5 and R6 form a simple low-pass audio filter. The audio signal is then amplified by an LM386 1-watt amplifier (IC5) to drive an 8-ohm speaker directly. Potentiometer R7 controls the volume, and the speaker connects to the 2-pin connector on one corner of the board. The board operates on power- supply voltages of +5 V and V p . V, can be any voltage between +7 and + 14 V. I generally use +12 V. Power can be applied either through the edge connector or the 4-pin power header. Pin assignments on the power header are arranged exactly the same as those on the Z8-BASIC Microcom- puter board presented in my last two articles, and the Sweet Talker board can conveniently use the same power supply. (See "Build a Z8-Based Con- trol Computer with BASIC," July 1981 BYTE, page 38 and August 1981 BYTE, page 50.) September 1981 © BYTE Publications lnc 45 Table 2: A list of useful words with their Votrax-notation phonemes, for ease in program coding. Word Phonemes Word Phonemes A A1 , AY, Y keyboard K, AY, Y, B, 01,02, R, D able A1, Y, B, UH3, L kill K, 11, 13, L about UH1, B, UH2, AH2, U1,T knowledge N, AH1, UH3, L, 13, D, J actual AE1, EH3, K, T, CH, U1, UH3, L add AE1, EH3, D L EH1, EH3, UH3, L adjust UH1, D, J, UH1, UH3, S, T language L, AE1, EH3, NG, G, W, 11, D, J large L, AH1, R, D, J B B, E1, Y left L, EH1, EH3, F, T back B, AE1, AE1, K length L, EH1, EH3, NG, TH basic B, A1, Y, S, 12, K listen L, 11, 13, S, 12, N been B, EH1, EH3, N before B, Y, F, 02, 02, R M EH1, EH2, M better B, EH1, EH3, T, ER make M, A1, AY, Y, K many M, EH2, EH2, N, Y C S, El, Y match M, AE1, EH3, T, CH came K, A1, AY, Y, M memory M, EH1, EH3, M, ER, Y can K, AE1, EH3, N message M, EH1, EH3, S, 12, D, J car K, AH2, UH3, R catalog K, AE2, EH3, DT, UH3, L, AW2, AW2, G N EH1, EH2, N change T, CH, A1, AY, Y, N, D, J name N, A1, AY, Y, M near N, AY, 11, R D D, E1, Y need N, El, Y, D data D, A2, Y, DT, UH1 next N, EH1, EH3, K, PAO, S, T date D, A2, AY, Y, T none N, UH1, UH3, N decide D, Y, S, AH2, EH3, Y, D decision D, Y, S, 12, ZH, UH3, N 02,01, U1 deliver D, Y, L, 12, V, ER object UH1, B, D, J, EH1, EH3, K, T obsolete AH1, UH3, B, S, UH3, L, AY, Y, T E E1, Y often AW2, AW2, F, 13, N early ER, R, L, Y omit 01, U1, M, 11, I3,T either E1 , Y, THV, ER other UH1, UH3, THV, ER empty EH2, EH3, M, P, T, Y end EH2, EH3, N, D P P, E1, Y exact EH2, EH3, G, PAO, Z, AE2, EH3, K, T package P, AE1, EH3, K, 11, D, J paper P, A1, Y, P, ER F EH1, EH2, F part P, AH1, R, T fact F, AE2, EH3, K, T person P, ER, S, UH1, N fault F, AW, L, T phone F, 01, U1, N final F, AH2, Y, N, UH3, L first F, ER, R, S, T Q K, Y1, IU, U1, U1 follow F, AH1, AW2, L, 01, U1 qualify K, W, AW1, L, 11, F, AH1, EH3, Y quantity K, W, AH1, N,T, 13, T, Y G D, J, E1, Y question K, W, EH1, EH3, S, T, CH, UH3, N game G, A2, AY, Y, M quick K, W, 11, 13, K good G, 001,001, D quiet K, W, AH1, EH3, AY, 12, T great G, R, A2, Y, T ground G, R, AH1, UH3, W, N D R AH1, UH2, ER grow G, R, 01, U1 raise R, A1, AY, Y, Z reach R, E1, Y, T, CH H A1, AY, Y, T, CH ready R, EH1, EH3, D, Y hand H, AE1, EH3, N, D remain R, E1, M, A1, AY, Y, N have H, AE1, EH3, V resistor R, E1,Z, 11, S, T, ER hear H, AY, 13, R heavy H, EH1, V, Y S EH1, EH2, S high H, AH1, EH3, Y safe S, A1, AY, Y, F sale S, A1, A2, AY, UH3, L 1 AH1, EH3, 13, Y schedule S, K, EH1, EH3, D, J, IU, U1, L important 11, 13, M, P, 02, 02, R, T, EH3, N, T scrap S, K, R, AE1, EH3, P include 11, 13, N, K, L, IU, U1, U1, D section S, EH1, EH3, K, SH, UH3, N inform 11, 13, N, F, 02, 02, R, M insert 11, N, S, R, R, T T T, E1, AY, Y instead 11, 13, N, S, T, EH1, EH3, D talk T, AW, K technical T, EH1, EH3, K, N, 13, K, UH3, L J D, J, EH3, A1, AY, Y terminal T, ER, M, EH3, N, UH2, L job D, J, AH1, UH3, B think TH, 11, 13, NG, K join D, J, 01, UH3, 13, AY, N time T, AH1, EH3, Y, M joy D, J, 01, UH3, 13, AY judge D, J, UH1, UH2, D, J U Y1, IU, U1, U1 jump D, J, UH1, UH2, M, P under UH2, UH2, N, D, ER uniform Y1, IU, U1, N, 13, F, 01, R, M K K, EH3, A1, AY, Y until UH2, UH2, N, T, 11, 13, L keep K, E1, Y, P up UH1, UH2, P key K, E1, Y urgent R, R, D, J, 13, N,T 46 September 1981 © BYTE Publicaripns Inc Table 2 continued: Word Phonemes Word Phonemes us UH1, UH2, S when W, EH1, EH3, N use Y1, 111, 111, U1, Z where which W, EH3, A2, EH3, R W, 11, 13, T, CH V V, E1, AY, Y while W, AH1, EH3, 11, UH3, L vacant V, A1, Y, K, EH3, N, T whiskey W, 11, 13, S, K, AY, Y valid V, AE1, UH3, L, 11, D white W, UH3, AH2, Y, T value V, AE1, EH3, L, Y1, IU, U1 who H, IU, U1, U1 vendor V, EH1, EH3, N, D, ER will W, 11, 13, L vent V, EH1, EH3, N, T window W, 11, N, D, 01, U1 verify V, EH1, R, 13, F, AH1, EH3, Y winter W, 11, 13, N,T, ER very V, EH1, R, Y wire W, AH1, EH3, AY, R via V, E1, AY, UH2, UH3 with W, 11, I3.TH victor V, 11, 13, K, T, ER withdraw W, 11, 13, TH, D, R, AW voice V, 01, UH3, 13, AY, S without W, 11, I3.TH, UH2, AH2, U1,T void V, 01, UH3, 13, AY, D word W, ER, R, D volt V, 02, 02, L, T work W, ER, R, K volume V, AH1, UH3, L, Y1, IU, U1, M wrong R, AW, NG W D, UH1, B, UH3, L, Y1, IU, U1 X EH1, EH2, K, PAO, S wage W, A1, AY, Y, D, J X-ray EH1, EH2, K, PAO, S, R, A1, 13, Y wait W, A1, AY, Y, T want W, AH1, UH3, N,T Y W, AH1, EH3, 13, Y was W, UH1, UH3, Z Yankee Y1, AE1, EH3, NG, K, E1, Y wash W, AW, SH yard Y1, AH1, R, D water W, AH1, UH3.T, ER year Y1, AY, 13, R watt W, AH1, UH3, T yellow Y1, EH1, EH3, L, 01, U1 wave W, A1, AY, Y, V yes Y1, EH3, EH1, S we W, E1, Y yesterday Y1, EH3, EH1, S, T, ER, D, A1 , 13, Y weapon W, EH2, EH2, P, UH1, N yet Y1, EH1, EH3, T Wednesday W, EH1, N, Z, D, A1, 13, Y your Y, 02, 02, R week W, E1, Y, K weigh W, A2, A2, Y Z Z, E1, Y went W, EH1, EH3, N, T zap Z, AE1, EH3, P west W, EH1, EH3, S, T zero Z, AY, 11, R, 01, U1 wet W, EH1, EH3, T zone Z, 01, U1, N what W, UH3, UH1.T zulu Z, IU, U1, L, IU, U1 wheel W, E1, Y, L Speaking in Phonemes Table 1 lists the 64 basic phonemes of the English language. At first glance, it appears complicated, but it is easy to understand and use. Take the word "call," for example. It is made up of three distinct phonemes, as follows (expressed in Votrax nota- tion): K, AW, L which correspond to the hexadecimal codes: 19 3D 18 Similarly, the word "disk" is broken into the phonemes: D, II, S, K which correspond to the hexadecimal codes: IE OB IF 19 See reference 3 for more details on this process. Causing the synthesizer to speak either of these words is done simply by sending the hexadecimal codes se- quentially to it. This is most easily done through a parallel I/O port under control of a program written in BASIC. Typically, if the synthesizer were connected to port on your computer, the routine for saying "call" would be coded as follows: 100 110 130 140 150 150 DATA 25, 61, 24 : REM Decimal Phoneme codes for "call" FOR A = l TO 3 : READ P(A) :NEXT A F0RA = 1T0 3 OUT 0,P(A) :REM Latch Phoneme code into SC-01 IF INP(0) = THEN GOTO :REM Continue if A/R not busy 160 NEXT A 170 OUT 0,63 :REM Send STOP code to SC-01 180 END Essentially any word or series of words can be spoken using this method. It isn't necessary for you to acquire special knowledge about word sounds to use a phonetic speech synthesizer, because many lists of word and phoneme equivalents are available. Table 2 is a list of some common words. A more extensive list is in preparation. Easy Interfacing What could be easier than pretend- ing that the Sweet Talker speech syn- thesizer is a parallel-interfaced printer? It just so happens that many computers already have a parallel output port in the form of a Centronics-compatible parallel printer port. This connection is avail- September 1961 © BYTE Publications Inc 47 Number Type + 5V GND -12V + 12V IC1 COM5016 2 11 9 IC2 COM2017 1 3 2 IC3 CD4049 1 8 IC4 MC1489 14 7 IC5 MC1488 7 1 14 RS-232 CONNECTOR |~~ DB-25 - 1 SWEET TALKER CONNECTIONS (TJ>PO Figure 6: Schematic diagram of a serial I/O interface for the Sweet Talker board, to be used in place of parallel I/O. The serial com- munication protocol is RS-232C. able on all Radio Shack TRS-80 Model III and expanded Model I com- puter systems, as well as many others. By connecting the Sweet Talker board as shown in figure 5, it is possible to fool the computer into thinking that the Sweet Talker is a printer, whereupon we can use LPRINT statements to drive it. The same machine-language routine in the BASIC interpreter that normally transfers ASCII (American Standard Code for Information Interchange) character strings to the printer will also work with the speech synthe- A BASIC LPRINT statement will transmit any ASCII characters be- tween the double quotes (except the quotation marks themselves and per- haps a few control codes) whether they spell out something humanly coherent or not. As table 1 illustrates, all of the phonemes correspond to ASCII characters which produce the equivalent 6-bit code (the lowercase letters "a" through "z" correspond to hexadecimal codes 21 through 3A). It is possible, therefore, to type an "@" for the EH3 phoneme (hexadecimal code 00) or a "> " for PA1 (hexadeci- mal code 3E). Using this technique, the program statement for saying "call" would be: 100 LPRINT "Y = X" It's a good idea to add a stop pho- neme (corresponding to ASCII "7") after the end of the word to cancel the last phoneme. The line then becomes: 100 LPRINT "Y=X"; "7"; The Sweet Talker speech synthe- sizer attaches to and handshakes with the computer in the same manner as a printer would. The A/R output is 48 September 1981 © BYTE Publications Inc Circle 266 on inquiry card. Model I Model III Products that set Precedents. T i ^ MAPPER cp/i CBASIC II CP/M THE , BEST WORD PROCESS $1000.00 VALUE ONLY TRADKMARKS: •TRS-WRidlo Shick/T«ndy Corp. "< P M/DI|H>I Rtsrarch •••C'BASK" ll/Compiler System! ••••PIIOENIX/Pllwillr Inc. $29 > rocessin 3L D DENTED ,INGS ible on selected rograrns through JGAB* Omikron's fficial users group. *farst connected to the Busy input, and the Unit Select line is grounded to simu- late printer attachment. The Sweet Talker's Enable input should also be grounded. The computer's LPRINT driver routine sends one character to the "printer" (speech synthesizer) and then checks the Busy line before send- ing another. When the Busy line is high again, the next character (pho- neme) is sent. The only area for concern is the pulse width of the data strobe (at- tached to Jl pin 21 with jumper JPl installed), as I previously mentioned. If it is less than 100 /is, a type-74121 monostable multivibrator should be added as indicated in figure 5. If you are unsure of the duration, add the circuit anyway. Once the interface is attached, a simple program can be used to test phoneme combinations. For example, sending "S*1L/@*KY" will cause the unit to say "automatic," and "Y2M*KIMB677" will make it say "continue." A simple test program re- quires only three lines: 100 INPUT A$ 110 LPRINT A$; "7"; 120 GOTO 100 Using a Serial Interface Your computer might not have a parallel printer port, but a serial one instead. While the interface is more complicated, you can also use LPRINT statements to drive the addi- tional circuitry shown in figure 6. This circuit is a full-duplex RS-232C serial interface which is capable of re- ceiving a phoneme transmitted serial- ly from the computer, converting it back to parallel form, and strobing it into the SC-01. The timing relationships between the interface and the computer be- come slightly more complex. When- ever a phoneme is loaded into the SC-01, the A/R line drops and the RS-232C Data Terminal Ready signal goes low. After the phoneme has con- cluded, the UART (universal asyn- chronous receiver/transmitter) trans- mits a jumper-selected character (op- tionally preset on UART pins 26 through 33) and raises the Data Ter- minal Ready line again. Proper tim- ing from the host computer can be ac- complished either by sending suc- cessive characters only in response to the "phoneme-concluded" code or by monitoring the state of the Data Ter- minal Ready line. The communication rate between the host and the synthesizer is switch- selectable from 50 to 19,200 bps using the COM5016 data-rate generator as shown. Communication is hard-wire selected for 8-bit data words, no pari- ty bit, and 1 stop bit. A more in- depth discussion of the data-rate gen- erator and UART was given in one of my previous Circuit Cellar articles ("I/O Expansion for the TRS-80, Part These items are available from: The MicroMint Inc 917 Midway Woodmere NY 11598 Telephone: (800) 645-3479 (for orders) (516) 374-6793 (for technical infor- mation) Votrax SC-01 Speech Synthesizer Chip (single integrated circuit) $70 (5 or more, price each) $55 Sweet Talker Phonetic Speech Syn- thesizer, parallel-port version. Includes SC-01 integrated circuit, data sheet, and user's manual. Assembled and tested $239 Sweet Talker Phonetic Speech Syn- thesizer, Apple II plug-compatible ver- sion. Includes SC-01 integrated circuit, data sheet, and user's manual, (separate power supply not required) Assembled and tested $149 MicroMint 3-voltage power supply (size 2% by 4Vz inches) Provides: +5 V, 300 mA + 12 V, 50 mA -12 V, 50 mA (-12V not required by Sweet Talker) Assembled and tested $35 All printed circuit boards are solder- masked and silk-screened. Please in- clude $2 for shipping and handling on any order. New York residents please include 7% sales tax. 2: Serial Ports," June 1980 BYTE, page 42). In Conclusion What can you do with a computer- controlled speech synthesizer? I'm sure you have a few ideas. In any case, the benefits of electronic speech synthesis will surely propagate as more people learn how to use it. Next Month: A discussion of EPROM program- ming and the design of an intelligent EPROM programmer. ■ References 1. Ciarcia, Steve. "Build a Low-Cost Speech- Synthesizer Interface," BYTE, June 1981, page 46. 2. Ciarcia, Steve. ' 'Talk to Me: Add a Voice to Your Computer for $35," BYTE, June 1978, page 142, reprinted in Ciarcia's Cir- cuit Cellar, Volume I. Peterborough NH: BYTE Books, 1979, page 77. 3. Fons, Kathryn and Tim Gargagliano. "Ar- ticulate Automata: An Overview of Voice Synthesis," BYTE, February 1981, page 164. 4. Gargagliano, Tim and Kathryn Fons. "Text Translator Builds Vocabulary for Speech Chip," Electronics, February 10, 1981, page 118. 5. Gargagliano, Tim and Kathryn Fons. "The TRS-80 Speaks: Using BASIC to Drive a Speech Synthesizer," BYTE, October 1979, page 113. 6. Gargagliano, Tim and Kathryn Fons. "A Votrax Vocabulary," BYTE, June 1981, page 384. 7. Lin, Kun-Shan, Gene Frantz, and Kathy Goudie. "Software Rules Give Personal Computer Real Word Power," Elec- tronics, February 10, 1981, page 122. 8. Weinrich, David W. "Speech-Synthesis Chip Borrows Human Intonation," Elec- tronics, April 10, 1980, page 113. 9. Wiggins, Richard and Larry Brantingham. "Three-Chip System Synthesizes Human Speech," Electronics, August 31, 1978, page 109. Editor's Note: Steve often refers to previous Circuit Cellar articles as reference material for the articles he presents each month. These ar- ticles are available in reprint books from BYTE Books, 70 Main St, Peterborough NH 03458. Ciarcia's Circuit Cellar covers articles that ap- peared in BYTE from September 1977 through November 1978. Ciarcia's Circuit Cellar, Volume II presents articles from December 1978 through June 1980. 50 September 1981 © BYTE Publications Inc Meet HP Series 80: Hewlett r Packard's newone-on-one computing systems for professionals. HP Series 80 Persona] Computers for Professionals: HP-85 ($3250*) and HP-83 ($2250*) specifications: 16K RAM expands to 32K, 32K ROM expands to 80K; CRT with integrated graphics; (HP-85 only; built-in thermal printer, cassette tape unit). Software includes VisiCalc PLUS, Information Management, Graphics Presentations, Surveying, Data Communications (Fall '81), Statistics, Regression Analysis, Math, Linear Programming, Waveform & Circuit Analaysis, BASIC Training. HP peripherals include flexible disc drives, printers and plotters. VisiCalc™ is a trademark of Personal Software, Inc. •Suggested retail price excluding applicable state and local taxes — Continental U.S.A.. Alaska & Hawaii. Circle 160 on inquiry card. Together, You can Analyze Technical Problems and Evaluate Solutions. Rapidly and Accurately. HP Series 80 personal computing systems provide the technical solutions you require. Quickly! Easily! Inexpen- sively! Analysis techniques that were formerly difficult and often impossible become part of your everyday work routine. You can evaluate functional behavior, select variable alternatives, perform cost analysis . . . and more ... all with greater accuracy and using more variables than you thought possible. Series 80, VisiCalc™ PLUS And You HP's VisiCalc PLUS is a major new software tool. It's an electronic worksheet that instantly recalculates results as you change the variables. You ask the what-if questions and immediately see their effects on your solution. No program- ming is necessary . . . you can become proficient with VisiCalc PLUS in a few hours . . . and then watch your horizons broaden. VisiCalc PLUS features many powerful functions including statistical analysis tools and the entire HP Series 80 BASIC math set. Plus graphics! Create professional presentations with curve-fitting plots, stacked or clustered bar graphs, exploded pie charts and line graphs, all in up to four colors, on paper or transparencies. ONLY FROM HEWLETT-PACKARD HP Series 80 personal computing systems are part of a forty-year tradition of electronic products built to uncompro- mising standards of excellence. Addi- tionally, HP Series 80 products are serviced by HP technicians and on-site service contracts are now available. We urge you to judge for yourself with a hands-on, one-on-one demonstration at your HP dealer. For locations, call TOLL-FREE 800-547-3400, Dept. 276E, except Alaska/Hawaii. In Oregon call 758-1010. Or write Hewlett-Packard, Corvallis, Oregon 97330, Dept. 276E 6 m HEWLETT PACKARD System Review The Big Board A Z80 System in Kit Form David Thompson 11740 NW West Rd Portland OR 97229 I built the computer on which I'm writing this article. Even though I'm no expert at computer hardware or soft- ware, I assembled this system in a matter of weeks, begin- ning with a kit called the Big Board. Manufactured by Digital Research Computers of Texas, the Big Board is a single-board computer that packs an impressive set of features into an inexpensive package. By not providing the cabinet, power supply, keyboard, monitor, and disk drives, Digital Research can sell this heart of a powerful Z80-based system for $650 in kit form. For an additional $50, the board comes with all the sockets soldered in place — a real convenience since all the integrated circuits are socketed. The board is the size of an 8-inch disk drive. It includes 64 K bytes of programmable memory, a 24-line by 80-character video generator, a keyboard interface, room Photo 1: The Big Board kit as the author received it. The board itself is in the center, with the documentation partly beneath it. On each side are plastic bags containing parts. Cables with con- nectors are in the rear. for four 2 K-byte ROMs (read-only memories, "bank switched" along with the video memory), and a floppy- disk drive controller. Options include parallel and serial ports and an on-board timer. History About three years ago, J B Ferguson, an electrical engi- neer from Dallas, wire-wrapped together a Z80-based, single-board computer and showed it to Jim Tanner of Digital Research. They then worked together to design a powerful, yet inexpensive, unit. Because of the small size of the board, they used LS (low-power Schottky) parts to keep heat problems to a minimum. According to Tanner, this choice almost killed the project. As recently as January 1980, LS parts were very expensive — too expensive, Tanner and Ferguson believed, for the Big Board to be salable. However, prices dropped so substantially before the end of that year, for both the LS parts and the memory, that Tanner and Ferguson decided to market the unit with a full 64 K bytes of user memory. Russell Smith designed the Big Board's monitor ROM and the custom BIOS (basic input/output system) for CP/M. The initial plan was to offer CP/M 1.4 with the board. But when version 2.2 became available, Smith went back to work and revised the BIOS. Source listings for both the monitor and BIOS are available free from Digital Research. Just ask for them when ordering the kit. The Kit The quality of the circuit board is readily apparent. It is solder-masked and tinned, which makes soldering easy. Solder-masking covers all the metal on the board except for spots where leads will be soldered. The compo- nent outlines and numbers are silk-screened on the top, and the holes for the component leads are plated through (they have metal deposited inside them to insure good connections). 52 September 1981 © BYTE Publications Inc Circle 211 on Inquiry card. Getting "STATIC" from our competition?, .if so, you're paying too much! Try Ours H79 64K Static $895 assembled 16K Static $179 assembled • STATIC RAMS • FULLY ASSEMBLED • FULLY TESTED • BURNED-IN • FULLY SOCKETED • INCREDIBLE VERSATILITY • BANK SELECTABLE • EXTENDED ADDRESSING • DELIVERY FROM STOCK • SAVE HUNDREDS OF DOLLARS • INTRODUCTORY PRICE - ORDER TODAY The Memory Merchant Story Why hasn't memory come down in price like it should? Here's what is being done for you. High Performance and Low Price 16K Static Board You want the most cost-effective, high performance memory boards that technology will allow. With that in mind we commis- sioned one of the top memory designers in the country. We told him to design the board with the user in mind. It had to sell for less than $200. It had to run cool and have low-power consumption. It had to have both extended addressing capabilities and bank select capabilities at no additional cost. You had to be able to de-select 1 K blocks so the memory could accommodate memory-mapped video displays or controller cards. The board had to be fast so a user could run his processor at full speed. Finally, the board had to be reliable and easy to install. He came up with all this and more. Here's a high 16K Ram, Model MM16K14 Specifications: • Four independent 4KX8 byte segments • One 4K segment equipped with IK windows • Compatible with both existing bank select type hardware and IEEE 696/S100 extended address protocol • Operation guaranteed to 4 MHz with Z-80 and to 5 MHz with 8085 processors • Low power consumption, typically 1.3 amps • Uses low power 300 ns 21 14 (1KX4) 64K Ram, Model MM65K16S Specifications: »• Operation guaranteed to 8 MHz • Compatible with both existing bank select type hardware and IEEE 696 extended address protocol • Fully loaded board (64K) draws 400ma. while max. current is 550 ma. • Four independently addressable 16K submodules on one board organized as 2 pair of independent 32K banks or as 1 64K extended address page. Each 32K bank re- sponds independently to phantom. Bank select logic is compatible with either Cromemco Cromix* or standard bank select software. • 2716 (5V) EPROM compatibility: Programmed 2716 EPROMs may replace any or all of the Ram components on the board. • New 16K (2KX8) Static Rams which combine extreme low power (40ma. ON; 5ma. OFF) with high speed (200ns max. access time). • Also available partially populated to 48K or 32K. *Crom(x is a trademark of Cromemco. 146 performance, fully assembled, tested and burned-in, guaranteed 16K board that we are introducing tor only $179. Runs on any S-100 8080, 4 MHz Z-80, or 5 MHz 8085 system. The Most Advanced 64K Static Board The end user wants State-of-the Art when he buys a 64K board. So we had our super designer put together the 64K board of the future with tomorrow's high speed processors in mind. This board had to work with all S-100 systems, with current processors and future (up to 8 MHz) processors. It had to be ultra-low power. It had to be designed so the advanced user could populate the board with programmed EPROMs for special applications. This board, too, had to have both bank select and extended addressing at no extra cost. The board was also designed to be used as a 32K or 48K board and we are selling it that way, too. Put in additional chips when you want to increase the capacity! OEM and dealer inquiries invited. No Risk Free Trial Circle 215 on Inquiry card. J4666 DOOUTTLE DR SAN LEANDRO, CA 94577 (415) 483-1008 m memory Tkzrchcint After you purchase one of our boards you may return it (intact) for any reason within 15 days after shipment and receive a full refund. Free Six Months Memory Insurance We will replace any board purchased from Memory Merchant that becomes defective through normal use for up to six months. Yes! Please send me the items listed below. I understand that if I'm not fully satisfied with the product, I can get a full refund within 15 days after shipment. (Send check, money order, or use your credit card.) Note to credit card buyers: For extra fast service phone (415) 483-1008 QUANTITY DESCRIPTION UNIT PRICE 64K $895.00 48K 749.00 32K 569.00 16K 179.00 SHIPPING & HANDLING S5.00/Board California Residents TOTAL Add 6% Tax SEND TO: MEMORY MERCHANT (Bl) 14666 Doolittle Dr. San Leondro, CA 94577 (NO C.O.D.'s) □ CHECK D MONEY ORDER □ VISA *D MASTERCHARGE (Must alia hove KM) City Zip Prices, terms, specifications subject to change without notice. for TRS-80 Models I & SuperSoft LISP allows the TRS-80 to become a complete Artificial Intelligence laboratory! It is the tool that takes you to the frontier of Com- puter Science. The SuperSoft LISP is a complete and full im- plementation. (It is NOT a subset!) It contains an efficient garbage collector which optimizes the usage of user RAM, and supports the TRS-80 graphics. Below are some features: • Runs in 16k level II (with only 6K overhead) • Fully implements atom property list structure. • PROG is supported. • FUNARG device is implemented. • Efficient garbage collection. • Complete with LISP editor and trace. • Allows complete range of single precision numeric data. • Works with old as well as new ROMs. • Contains 97 functions. • Sample Programs. The LISP package is supplied on tape or discette and with a complete user manual. cassette version: (requires 16K level II) Disk version: (requires 16K disk) (manual only: $15.00) $75.00 $100.00 VISA 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) SuperSoft First in Software Technology TRS-80 TRADEMARK TANDY CORP __Ar a nianrp Name Other hardware features Big Board Parallel port for ASCII- encoded keyboard; Manufacturer 24-line by 80-character video Digital Research Computers generator (composite or of Texas separated sync) POB 401565 Garland TX 75040 Options (214) 271-3538 Real-time clock; two RS-232 serial ports; Price two parallel ports Bare board with the monitor (adding the options is simply and character ROMs, $195 a matter of plugging in the Complete kit with sockets devices and adding a few and ICs, $649 resistors and capacitors) Complete kit with sockets already soldered in place; Software $699 2 K-byte monitor ROM (comes with the kit); Dimensions CP/M 2.2 is available com- 8.5 by 13 inches pletely configured for an additional $150 Processor Z80A Comments Putting the kit together re- System clock frequency quires some experience 2.5 MHz handling static-sensitive parts and a soldering iron. Memory Some knowledge of 8080 or 64 K-byte dynamic Z80 machine language or programmable memory; assembly language is four 2 K-byte ROMs important. (bank switched); Be sure to ask for a listing 4 K-byte static video of the ROM monitor and memory (bank switched) the BIOS (basic input/ out- put system) when ordering Mass storage your board. The listings are On-board controller for up free for the asking. to four 8-inch floppy-disk drives (single-density; each disk holds 240 K bytes for- matted) Although the Big Board's documentation is not as de- tailed or well organized as Heathkit's, it is well written and contains the information needed. The assembly pro- cess is explained step by step, complete with boxes you can check off. Because the parts' names and outlines are stenciled in place, the process takes only a few hours. What You Must Know If you have had a high school electronics class, can solder with a small iron, and know how to handle static- sensitive parts, you should have little trouble building the Big Board. But there is more to getting a system running than simply building the board. Though the Big Board is well designed and easy to interface with the keyboard, video monitor, and disk drive, interfacing with other peripheral devices requires some understanding of the hardware, the monitor, and the operating system. For in- 54 September 1981 © BYTE Publications Inc Circle 384 on inquiry card. location near- * est you. And don't settle for anything less than Hayes. mure: MVcwauit; cti uump ©Hayes The Hayes Micromodem II opens up your Apple Uto the outside world. Hayes Microcomputer Products Inc. 5835 peacntree comers East, Nora-oss, Georgia 30092 (404)449-3791 Micromodem II. Micromodem 100 and Microcoupler are trademarks of Hayes Microcomputer Products Inc. 'TM Apple Computer Inc. Micromodem II can also be used with the Bell & Howell computer. © 1981 Hayes Microcomputer Products Inc. typing a question mark instead of an escape, the Executive will list all file names that are valid matches for the string typed thus far. The Alto has a highly flexible and rugged file system. Unlike many file systems (eg: Digital Research's CP/M or Radio Shack's TRSDOS) that limit names to six or eight characters with a three-character extension, the Alto file system permits file names of up to thirty-one characters in length. When a file name is entered for the first time, the file name is stored exactly as typed, even with regard to upper- and lowercase. Since the file names may be very long, this permits a program- mer to use upper- and lowercase to improve readability. LongFile- Name.BigExtension is much easier on the eyes than LONGFILENAME. BIGEXTENSION. After the creation of a file, case is ignored when the user is speaking about the file, so either of the two names in the previous ex- amples, as well as longfile name.bigextension, would be valid. Alto files are divided into pages. Each page contains a small header that describes the current page, tells what file the page belongs to, and points to the places on the disk that contain the next and previous pages for the same file. This makes the file system almost indestructible. A pro- gram called Scavenger can auto- matically rebuild a broken file system. Of course, no Alto is an island, so software is needed to deal with the Ethernet network. Some of this soft- ware appears in the form of the NetExecutive (see photo 5b) and FTP (file-transfer program). The NetExec is a program that appears to be very similar to the Alto Executive, but it loads programs from across the net- work rather than from the local disk. This means that a user need not keep infrequently used or large programs locally. Instead, these programs can be loaded through the network (at an apparent speed of approximately 800,000 bits per second) only when needed. FTP performs similar feats of file manipulation, but in a con- siderably more flexible manner. Although a great deal of software written for the Alto is in BCPL, there is a new contender for software development called Mesa. Mesa is a Pascal-like language that is incom- patible with BCPL because of dif- ferences in their respective microcodes. Mesa is expected to be the programming language for the successors of the Alto (see photo 5c). BCPL and Mesa are the system languages for the Alto, which means that the system utilities and many ap- plications programs are written in them. Other languages are available on the Alto, however. Much of the research work done on the Alto at Xerox is written in Smalltalk, an object-oriented language that is both easy to learn and highly powerful (see the special August 1981 BYTE issue (5e) M Ull Photo 5: Examples of Alto software. Photo 5a shows a display of the Alto Executive, with an example of star and question-mark notation. Photo 5b shows the NetExecutive (similar to the Alto Executive, but it allows access to resources on the Ethernet). Photo 5c is a typical Mesa program being edited by Bravo; note the different typefonts used in the program listing. Photo 5d is a directory from the Neptune directory editor. The file names in black have been selected for further operations such as printing or erasure. The cursor is displayed as a cross in a circle. Photo 5e illustrates Bravo's ability to change fonts (there are hundreds of fonts for the Alto, from Gothic to Elvish Runes; the central paragraph in this display has been changed to Greek). The document in the bottom window has been converted to the form shown in the top window. 64 September 1981 © BYTE Publications Inc Circle 233 on inquiry card. MicroMed™ and MicroDent™ make your practice perfect!" They're the real solution to the problems confronting every physician's and dentist's office. Each is a unique package, developed through years of work in close conjunction with doctors and dentists. They'll help you treat your patients more efficiently and accurately, while saving you time and money in the process. Versatility. Whether you are in private practice or a member of a busy group, there's sufficient capacity to handle your needs. Thousands of patients can be accommodated on floppies, and even more on hard disk. MicroMed and MicroDent can easily handle everything in your practice from billing to patient records to complex insurance forms . With millions of hours of actual use in medical and dental offices throughout the country, they stand alone at the top, in a class by themselves. We know you're after solutions, not more problems. Our menus are simplicity itself, and are designed for your convenience (not our programmers'). The computer displays your options at every step. What could be simpler? Your own office staff can easily take care of the routine so that you can devote your valuable time to your patients. You are the boss. Forget about problems with outside billing services or manual record-keeping. You exercise absolute control over your billing procedures. Finger-tip patient recall lets you know instantly whose accounts are due and what services were performed. Account aging is automatic, and past-due notices or statements are printed and addressed, ready for mailing. All types of reports may be requested to help you better understand your finances and cash flow. Daily backups are created automatically. Multiple Insurance Forms. Many patients have several different types of insurance coverage. With MicroMed and MicroDent you can enter almost any form, keep track of which patients it applies to, and get it processed and ready for mailing. When new forms come out (as we all know they will) you don't have to pay for custom programming, you can modify the form print format yourself. With our exclusive Formulator" ' system it takes just minutes. The biggest surprise of all is that MicroMed and MicroDent are just $1500 each. Plus, having your own office computer provides you with great tax advantages. If you like what you see, contact your nearest computer store. They can provide you with MicroMed or MicroDent on any CP/M® based computer for an amazingly economical price. Or, if you already have a computer, a demo disk and manual set is available for just $75, and allows you to run the entire program. The manual separately is $50. Send for one today, and make your practice perfect! Features: • Automatic billing for any patient load • Handles practices with up to 20 doctors • Accepts all insurance forms • Exclusive "Formulator" form system • Multiple insurance coverage • Insurance preauthorization • Automatic statements with aging • Instant access to patient records • Full transaction and treatment details • Cumulative totals by doctor • Profitability analysis reports • Mailing list maintenance • Can be linked to word-processing • Appointment recall with reminders • Maintains hospital and lab codes • Keeps track of referring doctor codes Demo disk and manual set $ 75! Dealerships are available to established computer vendors on a territorial basis. '"MicroMed. MicroDent, and Formulator are trademarks of SoftwareHows •CP/M is a registered trademark of Digital Research .J Copyright «1981. SofrwareHows P.O. Box 36275, Los Angeles, CA 90036 (213) 731-0876 . TWX: 910-321-2378 1378 Photo 6: Use of the Draw program. In photo 6a, points are placed with the cursor, and curves and lines are filled in by the program. Photo 6b shows that lines may be "painted" with a variety of "brushstrokes" (the cursor has changed to a small paint- brush). In photo 6c, texture is given to the lines; dotted lines are created with the scissors cursor. Photo 6d shows that the picture may be mathematically manipulated; a new figure may be created by reversing, tilting, or stretching a copy of the original. on the Smalltalk language). Another supported language is LISP, a list- processing language that is very popular in the artificial intelligence research community. Using the Screen A system with the advanced graphics capability of the Alto will make extensive use of those facilities. The screen may be broken up into windows, and each window may be accessed in a different manner, if desired. Many Alto programs use only the mouse and screen windows for program control. For instance, the Neptune program is used for man- aging the contents of the Alto's local disks (see photo 5d). A file may be deleted simply by touching the file name with the cursor, then touching the Delete spot on the screen with the cursor. As the cursor enters a new window, it may change shape, perhaps appearing as an arrow in one window and a paintbrush in another. Since the Alto is used extensively for research in the office automation field, a good text editor is an obvious requirement. Bravo is a text editor and formatter widely used on the Alto. In the tradition of screen- oriented editors, the current state of the user's file is always shown on the screen. Bravo is controlled partly by keyboard commands and partly by mouse commands. It allows a user to open windows into one or more files. Text may be added or deleted by pointing at the desired location on the screen (see photo 5e) with the mouse cursor, and giving a command via the keyboard or mouse. Bravo supports many different fonts and allows the user to change easily from one font to the next. In addition, Bravo remembers the changes that have been made to a document and allows the user to reverse any or all changes. Bravo allows the user to edit and format text, but often a person may wish to include illustrations in a document. To do this, a program called Draw is used. Draw is an in- teractive sketch-pad program that provides a variety of tools for creating and manipulating pictures made from lines, curves, and text. Draw divides the screen into a number of windows (see photo 6). The left side of the screen contains a menu of commands and a variety of brushstrokes that can be selected. The top of the screen contains an area for text commands and messages from the program. The middle of the screen is the picture workspace. Curves can be drawn by moving the cursor directly, or by selecting several points and allowing Draw to mathematically fit a curve to those points. Once an object is defined, it can be repainted using a number of brushstrokes. Since this is very similar to the techniques used by ar- tists and calligraphers, quite a bit of artistic expression is possible. An object can be duplicated, rotated, stretched, or shrunk, by means of a small set of commands and mouse gestures. The Network Each Alto is assigned an Ethernet address that identifies it uniquely on 66 September 1981 © BYTE Publications Inc Circle 104 on inquiry card. dntasouth announces. •• THE TOTAL PRINTER PACKAGE! //// With so many matrix printers on the market today, it may seem tough to find exactly the right one for your application. Some models may offer the speed you need, others the communications flexibility and still others the forms handling capability. But no printer offers all the features you need... until now. The DS180 matrix printer provides the total package of perfor- mance features and reliability required for applications such as CRT slave copy, remote terminal networks and small ,to mid-range systems. Not a "hobby-grade" printer, the DS180 is a real work- horse designed to handle your most demanding printer require- ments. And pricing on the DS180 is hundreds of dollars below competitive units. High Speed Printing -Bidirectional, logic-seeking printing at 180 cps offers throughput of over 200 ipm on average text. A 9-wire printhead life-tested at 650 million characters generates a 9x7 matrix with true lower case descenders and underlining. Non-volatile Format Retention -a unique programming keypad featuring a non-volatile memory allows the user to configure the DS180 for virtually any application. Top of form, horizontal and vertical tabs, perforation skipover, communications parameters and many other features may be programmed and stored from the keypad.When your system is powered down, the format is retained in memory. The DS180 even remembers the line where you stopped printing. There is no need to reset the top of form, margins, baud rate, etc. . . . it's all stored in the memory. If you need to recon- figure for another application, simply load a new format into the memory. Communications Versatility -The OS 180 offers three interfaces including RS232, current loop and 8-bit parallel. Baud rates from 110-9600 may be selected. A 1K buffer and X-on, X-off hand- shaking ensure optimum throughput. Forms Handling Flexibility -Adjustable tractors accommodate forms from 3"-15". The adjustable head can print 6-part forms crisply and clearly making the DS180 ideal for printing multipart invoices and shipping documents. Forms can be fed from the front or the bottom. If you would like more information on how the DS180's low-cost total printer package can fill your application, give us a call at Datasouth. The DS180 is available for 30-day delivery from our sales/service distributors throughout the U.S. data©®* computer corporation 4740 Dwight Evans Road • Charlotte, North Carolina 28210 • 704/523-8500 Photo 7: The multiplayer Trek program. This game is played entirely under mouse control. The lower portion of the screen shows a short-range sensor scan; above is the long-range display, and navigation and weapons controls. the network. A typical Ethernet ad- dress might be 50#100, which is meaningless to most people. To per- mit an easily remembered distinction between Altos, each is assigned a name. For instance, the Altos at Stan- ford are named after rivers and mountains in California State parks; Altos at CMU are named after jewels, and Altos at Xerox are named after people. This leads to such interesting names as Cypress, Turquoise, or Machiavelli, which are considerably easier to remember than 50#100. Alto networks do not consist en- tirely of Altos. Several other devices are connected to the Ethernet net- work. One type is called a server. Servers are userless Altos that are dedicated to some specific function. A server might be connected to a printer. Thus, printing a file would actually consist of sending the proper messages to a Printing Server. One common type of server is a File Server. These machines support extra-large disks and are repositories for programs and files that are too large or too infrequently accessed to make storage on individual machines worthwhile. The Stanford File Server is named Lassen. Photo 8: The multiplayer Mazewar game. The eye represents the persona of an opponent. Any Alto on the net can join or leave the game at any time. Due to the design of the network and the Altos, a new Alto can be wheeled in, plugged into the network medium (standard coaxial cable), and, with a blank disk pack fresh from the factory, become entirely functional with a full set of software in a matter of minutes. An Alto can also be disconnected, moved to another port in the coaxial cable, and reconnected without affecting either the performance of the network or the Alto. Several programs exist that take advantage of the distributed process- ing capabilities inherent in the Ethernet network. Of all of them, the most enjoyable are the games. Trek is a multiplayer "spacewar" game that is controlled primarily by the mouse (see photo 7). Mazewar is a multi- player romp through a realistic labyrinth (see photo 8). The unique feature of these games is that large numbers of users can join or leave the game as they please without affecting the play of the others. Since all the Altos can listen to the same packet (block information on the Ethernet) at once, the game program is never running on any single coordinating machine. Instead, it is running in- dependently on every participating Alto. The Future A stand-alone Alto is usable, but the best configuration is a group of Altos connected by an Ethernet system. Since the Ethernet system is a local network, a special device called a gateway was developed to allow local Ethernet networks to speak to other Ethernet networks or packet networks of other types. Many com- panies are researching network schemes that would allow packet transmission across cable-television lines. Since these cables are currently installed in many homes and buildings, it is not difficult to imagine a city with an "information grid," analogous to the electric-power grid that exists today. Combined with an electronic mail system (a prototype called Laurel is used on Altos today) the possibilities are staggering. The Alto has been around for several years. As research tools go, it is covered with moss and gathering dust. But new products will be ap- pearing on the market based on the expertise gained in producing and using the Alto. The next few years should show a dramatic increase in the quality of personal computing and the ability to interconnect per- sonal computers. And the Alto is one of the first personal computers that satisfies the needs of the computer scientist as well as the secretary or businessman. ■ References 1. Lampson, B W and E Taft. Alto User's Handbook. 1979. 2. Metcalfe, R M and D R Boggs. "Ethernet: Distributed Packet Switching For Local Computer Networks." Communications of the ACM 19,7, July 1976, pages 395 through 404. 3. Shoch, J F and J A Hupp. "Measured Per- formance of an Ethernet Local Network." Communications of the ACM 23,12, December 1980, pages 711 through 721. 4. Thacker, CP.EM McCreight, B W Lamp- son, R F Sproull, and D R Boggs. Alto: A Personal Computer. Tech Rep CSL-79-1 1. Palo Alto CA: Xerox Palo Alto Research Center, August 1979. (To appear in Com- puter Structures: Readings and Examples, Second Edition. Siewiorek, Bell, and Newell, editors.) 68 September 1981 © BYTE Publications Inc Customizable The Unique Difference that Sets VEDIT Apart in Full Screen Editors Total user customizability is a predominate reason that over a thousand users find VEDIT the easiest to use full screen editor. It makes VEDIT the only editing package which allows you to determine your own keyboard layout and use the cursor and special function keys on any terminal having them. And only VEDIT fully supports all of the newly available terminals. It may come as a surprise to you, that with any other editor or word processor, you will have to memorize obscure control characters or multi-character sequences, while your terminal's extra keys and editing functions go unused. The customization extends to setting the default tab positions, scrolling methods and much more. It's almost like designing your own editor for your system, applications and preferences. And all of this is easily done with the setup program which requires no programming knowledge or 'patches', but simply prompts you to press a key or enter a parameter. Unequaled Hardware Support 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, status line and reverse video are used on 'smart' terminals. All screen sizes are supported, including large ones such as the 60 X 80 format on the Ann Arbor Ambassador terminal. Special function keys on terminals such as the Heath HI 9, Televideo 920C and IBM 3101, and keyboards producing 8 bit codes are all supported. The memory mapped version is extremely flexible and supports bank select and hardware cursors such as on the SSM VB3. With this level of customizability and hardware support, you will feel for the first time that the software was optimally designed for your system. Fully Compatible Replacement for Ed Since VEDIT creates and edits standard text files of up to one diskette in length, it serves as a replacement for the CP/M standard editor ED. Of course, you benefit from the fastest and easiest to use 'What you see is what you get' type full screen editing available, fast disk access and an editor which takes up only 1 2K of your valuable memory space. With VEDIT you will never again need or want to use the slow and tedious ED. Special Features VEDIT is more than just a full screen editing replacement for ED, it gives you many new editing capabilities, such as a scratchpad buffer for moving and rearranging sections of text, complete file handling on multiple drives and iteration macros. Amoung its special features you will find automatic indenting for use with structured programming languages such as Pascal and PL/1, and other special facilities for Assembler and COBOL. A real time saver is the ability to insert a specified line range of another file anywhere in the text. Unlike most software, VEDIT will even tolerate your mistakes. For example, one key will 'Undo' the changes you mistakenly made to a screen line, and the disk write error recovery lets you delete files or insert another disk should you run out of disk space. Ordering Many dealers carry VEDIT, or you may contact us for fast delivery. Specify the CRT version, your video board or microcomputer, the 8080, Z80 or 8086 code version, and disk format required. VEDIT for 8080 or Z80: Disk and manual $130 VEDIT for CP/M-86: Disk and manual . (NEW) $ 1 85 Manual: Price refunded with software purchase $ 1 5 VISA or MASTERCARD Welcomed CP M and MP/M are registered trademarks of Digital Research. Inc. Apple II is a registered trademark of Apple Computer. Inc. SoftCard is a trademark ol Microsoft. TRS-80 is a trademark of Tandy Corp. North Star ■ Cromemco * Heath H8/H89 » SuperBrain * Apple II Softcard ' Most other CP/M Systems with CRT or Memory Mapped Displays TRS-80 Model II & Model MP/M • CP/M-86 CompuView Products Inc. 618 Louise, Ann Arbor, Michigan 48103 * Telephone (313) 996-1299 Circle 89 on inquiry card. IF YOU W\NT TO START \OUROWN COMPUTER OOMIANX WU NOW H^VE THE COMPUTER TO START WITH The entrepreneurial spirit runs rampant in the computer industry. In fact, it's come to our attention that a significant number of the technical/engineering types have some thoughts of starting their own company. So we have come out with a computer for them. And for those entrepreneurs with- in companies who are in a hurry to get their hot new project to market in a hurry. It's called the MPT/100. As you can see, the MPT/100 computer is small enough to fit in whatever corner you set aside for furthering your own ambitions. And it'll cost you less than the price of a basic new car. This computer is anything but basic. Inside the MPT/100, you'll find a 16-bit microNOVA™ computer. 64K bytes of memory 80 column by 24 line screen. Full keyboard with numeric pad. 716 KB of on- line storage on two 358 KB mini-diskettes all packaged in a system that has the kind of software, compatibility with more powerful computers, ease-of-use and reliability that ^ desk-top computers are noted for not having. Also unlike most desk-top computer software, some very sophisticated (read easy-to-use) big computer software is avail- able for the MPT/100 com- puter: A multi-tasking FORTRAN that meets all the ANSI standards. A PASCAL that executes at assembly lan- guage speeds. An ANSI compatible BASK that lets you write enormously complex pro- grams that take up only a little space. A 70 BYTE September 1981 full range of user-friendly interactive program- ming aids. And MP/OS, an operating system anyone who's into operating systems will tell you is one of the most advanced in the world. (Anyone who considers any of the above to be of trivial importance should consider the fact that a single line of application code costs a good deal more than many microcomputers. And that cost is only going one way.) Saving money on programming is only part of the attraction of the MPT/ 100. It also saves you time. So you can get your company up and running before anyone can do the same thing. As you grow, all the software you've written, all the peripherals you've interfaced, all the blood, sweat and tears you've put into your company will grow with you. Because we've invested no small amount of energy working to make our com- puters compatible. The point here is that the MPT/ 100 can make you what a lot of companies have become with Data General. Like Aero Systems Engineering, of St. Paul, Minnesota, for example. They're far and above the leading manufacturer of com- puterized aircraft jet engine testing systems. A position they came to occupy partly by building test facilities that could cut fuel con- sumption rates by 35%. Partly because of our world-wide service. And partly because they didn't have to wait eighteen months to get our computers. There is no stopping you from doing the same thing. If you want to get more detailed in- formation about the MPT/ 100 computer, call your local Data General office or your Data General manufacturer's representa- tive. Or the distributors listed below. Or write us at: MS C-228, 4400 Computer Drive, Westboro, MA 01580. MPT/100 computers are available for off the shelf delivery from : SCHWEBER, HALL-MARK, KIERULFF, ALMAC/ STROUM and R.A.E. in Canada. Look at it this way. AH of you who want to start your own computer company, are very lucky people. We didn't have anybody to write to when we got started. IrDataGeneral We take care of our own. microNOVA is a registered trademark of Data General Corporation. ©1981, Data General Corporation. BYTE September 1981 71 Tree Searching Part 1: Basic Techniques Gregg Williams, Senior Editor It is estimated that there are more possible games of chess than there are atoms in the universe. This means that if a computer could generate one million chess moves a second, it would take approximately 3.2 X 10 60 centuries to generate all possible games. How, then, can a $200 microprocessor-based chess game (faced with analyzing a situation so complex) play not only minimal but fair-to-good chess? Several tech- niques are necessary, but one of the most powerful in the field of artificial intelligence is known as tree search- ing. Tree searching allows a computer to determine the best of many alter- natives, while at the same time evaluating as few partial solutions as possible. Part 1 of this article deals with the basic techniques of tree searching on three levels: theory, im- plementation (through several BASIC programs illustrating the major techniques), and experimentation. It PARENT NODE' la) SUCCESSOR NODES (b) Figure 1: Nomenclature of trees. Figure la gives the graphic representation of the state space of a problem as a tree. Trees are characterized hy having only one start node (S), by containing only nodes that can be reached via the start node, and by having no arrows that lead to the same or lesser depth. Nodes n 2U n 32 , and n 27 are examples of ter- minal nodes; nodes n, 2 , n lit and n 33 are examples of nonterminal nodes; nodes n 31 and n lt (shown in color) are goal nodes. Note that a goal node can be either terminal or nonterminal. Figure lb shows the relationship between parent node n, 3 and successor nodes n 26 and n 21 . Here, n, 3 is said to be expanded to generate n 26 and n I7 . will introduce basic terminology and some well-known exhaustive tree searches (those that will eventually generate all possible partial solutions), as well as an illustrative BASIC program (to solve the familiar sliding blocks "15-puzzle") that will be used in both articles. The second part will deal with admissible heuristic searches that use informa- tion about the system being searched to cut down on the number of false leads pursued; it will also cover nonadmissible heuristic searches, which attempt to find a quicker solu- tion at the expense of losing the cer- tainty of a guaranteed optimal solu- tion, or of finding a solution at all. Basic Terminology The purpose of artificial in- telligence, according to one school of thought, is to produce computer pro- grams that will solve problems not easily solved by computers — prob- lems that can be solved by an "in- telligent" agent (usually a human). The solution to many of these prob- lems can be seen as the attempt to ar- rive at a solution (or goal) whose properties are unambiguously de- fined, from an initial state (or node), according to some specific set of rules. Between the starting node and the goal node are other nodes that represent intermediate positions. We 72 September 1981 © BYTE PublkaHora Inc -Peachtree Software Eliminates The- PEDUNCLE It certainly is nice to know those beautiful spring blossoms on flowering peach trees are sessile blooms. Sessile, according to Webster, simply means the flowers are not raised upon a peduncle. Well, thank goodness for that! And Webster adds that a peduncle is the stalk that sup- ports the fructification in Yo ou're really going to ap- preciate the "self teaching" simplicity of Peachtree Software's documentation. You'll be on your own in no time, with no need for "support." Our learn- by-doing manual shows you exactly what will appear on the screen. Menu driven, our pro- grams prompt you at every point with the selections available. There's sample data for self- training and practice, too. So goodbye forever to peduncles . . . who needs 'em! Wide variety of packages, all from the same tree. Here's just a sample. Magic Wand™ - With this ex- tremely popular word processing system, a minimum of com- mands performs basic functions. It's remarkably easy to use. And you can now add Magic Spell™ , the "dictionary" with 20,000 words. Sales Tracker™ is our most comprehensive product— a sales order processing system that could well be the most sophisti- cated microcomputer software some thallophytes. Big deal. . . . We at Peachtree Software are very pleased to assure you that due to our advanced technology, our thallophytes fructificate with- out the need of any support whatsoever! Software dealers, rejoice . . . your peduncle wor- ries are over forever. Isn't modern science wonderful? TheVery Best'Dff-The-ShelT Software Is "Off-The-Tree!' ever developed. It has the power of ANSI/COBOL and floppy or hard disk support. User- selectable options bridge the gap between accounts receivable and inventory. Peachtree Series 5 is an all new generation of BASIC General Ac- counting packages. It includes such user-requested features as the capability to access and up- date, simultaneously, both the Accounts Receivable and Inven- tory data files. Hard disk option. Installation guides. Expanded data and report capability. The Peachtree Series 40 is adapted for the Apple II 's standard 40-column screen and single-density 514-inch disk drive, using the SoftCard™ from Microsoft**. The series includes General Ledger, Accounts Re- ceivable, Accounts Payable, In- ventory, Mailing List, Payroll, and Magic Wand™ I t takes time to grow a tree, and we've been in the business ever since microcomputers started springing up in homes and businesses all across America. So our software systems are time-tested and user-feedback refined. Trust the Tree for Un- surpassed Documentation. For Feature-packed Systems, utiliz- ing the latest hardware technol- ogy. And trust the Tree for sophisticated programs, so easy to use, that "peduncle" may soon disappear entirely from the En- glish language! There are more than 20,000 Peachtree Software packages in use today. To get yours, see your nearest dealer or call 1- 800-835-2246 Ext. 35. In Kan- sas call 1-800-362-2421 Ext. 35. TheVery Best "Off-The-Shelf "Software Is "Off-The-Tree; PEACHTREE SOFTWARE, 3 Corporate Square. Suite 700, Atlanta, Georgia 30329 (404) 325-8533 Telex II: 810-75 1-0273 PEACHTREE ATI.. "Apple II is a trademark of Apple Computer, Inc. "Microsoft and Still Card art [radcrnarksof Microsoft Consumer Products, Inc. Peachtree Software, Magic Wand. Magic Spell, and Sales Trackers are trademarks Of Reachtree Software, Incorporared, Circle 287 on inquiry card. BYTE September 1981 73 are interested in the particular se- quence of nodes that makes up the shortest path to one of several possi- ble goal nodes. Many nodes (usually an overwhelming number) do not lie on the optimum path, and the pur- pose of tree-searching methods is to explore as few of these as possible. A number of problems that do not seem to lend themselves to tree searches can be made to do so when described in a finite-state representa- tion. Sometimes, in the case of prob- lems that have a continuous (and therefore infinite) range of variation, this means quantizing the problem into a finite number of discrete steps: an example is considering the range of temperatures of 20° to 30 °C as a set of discrete temperatures — say, 20.0°, 20.1°, 20.2°, ... 29.9°, and 30.0°. Theoretically, this results in some loss of accuracy, but most problems can be quantized in sufficiently small in- crements that accuracy is not a prob- lem. A finite-state representation con- sists of the following: a start node, a well-defined node or set of goal nodes, and a set of rules or operators that allows the user to generate all permissible successor nodes from a given node. In some cases, the path from a node to its successor node (that is, one generated by the single Figure 2: A directed graph. This figure, which represents the structure of many "real-world" problems, differs from a tree in that successors may be in the same or a "shallower" depth (note colored arrows). The successor of n 33 is n 12 ; the successor of n 17 is n, 3 . Tree-searching algorithms can be modified to handle graphs, but this article will deal exclusively with trees. application of an operator to the parent node) may have a cost associated with it, with the cost of a goal node being the total cost in- curred along the shortest path from the start node to the goal node. The set of all nodes that can be derived from the start node is called the state space. A tree is one possible representa- tion of the state space of a problem. As shown in figure 1, nodes are represented as points, and the rela- tionship between a given node and its successor is shown by a directed arrow that points from the parent node to the successor node. We will label the start node S, and each of the other nodes' according to its rank (distance from the start node) and lateral position within the set of all nodes with the same rank (this is an arbitrary labeling, but it is orderly and useful). Referring to figure la, nodes n„, n X2 , and n 13 are all the nodes of rank one. Node n 12 has two successor nodes, n 24 and n 25 . Node n 4J is the only node of rank four. Some nodes do not yield any new states upon application of the operators that define the transition from one state (node) to the next. These are called terminal nodes; ex- amples in figure la are nodes n 21 , n 2 2, n 2 3, n 25 , n 27 , n 31 , n 32 , and n 41 . Nodes marked G are regarded as goal nodes; they can be either terminal or nonter- minal nodes. (a) s = ® ABDCj) GOAL COST= 18 (b) Figure 3: The traveling-salesman problem. Given the map in figure 3a, the objective is to find the shortest route from city A through cities B, C, and D. The tree of figure 3b gives the finite-state representation of the problem, with each node being a partial trip (eg: ADC is the trip from A through D and C) that has a cost dependent upon the route taken. Here the problem is discrete, and any node has only a finite number of suc- cessors; at node AD, only two "next moves" are possible: ADB and ADC. The shortest route is shown in color. 74 September 1981 © BYTE Publications Inc "Together we're working to better serve mankind!' "Speaking on behalf of Vector computers, I'm pleased to announce that TRW Customer Service Division will provide a nationwide, nine-month on-site service warranty that you, the end-user, will receive absolutely free* "I'd also like to add that this is a unique program. It's actually the first time a microcomputer has had this kind of comprehensive nationwide on-site service — especially from a company of experts like TRW. "Now you have even more security when you buy a Vector. In addition to increasing your personal productivity, helping you make faster decisions, and improving your business, we offer a network that will service us right in your office if we ever need it. At no expense to you. "Right now, you can get quick, dependable service in Los Angeles, New York City, Denver, Dallas, Chicago, San Francisco, Northern New Jersey, Philadelphia, Atlanta, and Boston. With more cities on the way. For more information and your nearest Dealer, call us at 800-423-5857. In California, call 800-382-3367. Or write to us at 31364 Via Colinas.Westlake Village, CA 91362. "TRW and Vector. Now that we're helping each other, there's no telling how much we can accomplish for you'.' Vector Graphic Inc. COMPUTERS FOR THE ADVANCEMENT OF SOCIETY. Circle 376 on inquiry card. 'Within 50 mile radius of aTRW service center. Circle 123 on inquiry card. 68000 p? on the S-100 Bus? YES, AVAILABLE NOW FROM DUAL SYSTEMS! □ 8 mHz 68000 microprocessor. □ 16-megabyte direct addressing. □ 32-bit internal arithmetic. D Minicomputer type instructions including MULTIPLY. □ FULL IEEE-696 S-100 compliance. Runs with all 4 mHz S-100 boards and automatically runs faster when accessing Dual Systems memory boards, for FULL SPEED OPERATION OF THE 68000. □ Powerful vectored interrupts. 7 Vectored interrupts, including NMI, as well as alternate mode having up to 256 interrupts. □ On board monitor ROM for immediate use. D Connector for future addition of memory management unit for multi-user operating systems. D Built to the highest industrial standards with 200 hour burn-in. CPU/68000 CPU board $1195 32K-byte 8/16-bit NONVOLATILE RAM board, for secure storage of programs you are developing. Allows FULL SPEED CPU operation. CMEM-32K, per 32K-bytes . . $895 32K-byte 8/16-bit EPROM board, EPROM-32K $395 Serial I/O board, SIO-2 $285 All of the above with cabinet, power supply and backplane $3685 OEM and Dealer pricing is available. Sales representatives in most metropolitan areas. system reliability/system integrity DUAL SYSTEMS CONTROL CORPORATION 1825 Eastshore Hwy, Berkeley 94710 (415) 549-3854 • TWX 910 366-2035 Often the state space of a problem will allow a node to generate as suc- cessor a node of equal or lesser rank, as shown in figure 2. In this case, the resulting representation is called a graph (or, more completely, a directed graph). This will call for only a slight addition to the search strategy, but the difference should be noted. Finally, as mentioned before, a transition from a node to its successor may have a cost associated with it. If so, the arrow connecting the two will be labeled with the cost; otherwise, the arrows are unlabeled and each is assumed to carry a unit cost. Some Examples First we will examine a discrete example: the traveling salesman problem. A traveling salesman in city A must travel to cities B, C, and D, in any order. Given the map in figure 3a, what order of cities gives the shortest total mileage? In this problem, the nodes are par- tially completed (or completed) trips described by a sequence of the letters A, B, C, and D, restricted by the rules that follow. The start node is A (salesman in city A, no traveling done). Four goal nodes describe various routes, ABCD, ABDC, ADBC, ADCB. The rules are infor- mally described: from a given node, add the letter of any city that con- nects to the last city visited and that has not yet been visited. Since the number of cities is small, a full state-space tree is possible (figure 3b), and it is clear that the shortest route is ADBC, with a distance (cost) of thirteen. But what if there are ten cities? Twenty? What if some roads are one-way? Next we see a continuous example (here the state space must be cut into a finite number of discrete values). You have a faucet, a sink, and an empty glass with a horizontal line on it: fill the glass up to the line. First we must quantize the prob- lem. Suppose we say that the glass holds 100 ml of water. We can reasonably set the smallest unit of water to be manipulated at one milliliter. The state of the problem is the amount of water in the glass, and the problem has 101 possible states: ADD 100 ml. 76 September 1981 © BYTE Publications Inc Figure 4: The "quantization" of a continuous-solution space. Shown is a partial tree for the problem of filling a water glass to a specified mark. It is continuous in that the prob- lem space (the amount of water in the glass) can hold an infinite variety of states (amounts of water). By considering the glass to hold water only in single-milliliter increments, the problem space becomes discrete and finite, and thus can be represented to a computer. Goal nodes exist where the water level matches the mark on the glass. Circle 24 on inquiry card. > lake a look at our EPROM blaster for your Apple or TRS-80; .0 % ./ y &> : announces the most itile EPROM burner available today for your TRS-80 model I and lit or Apple computer . . . the Apparat PROM Blasting system (A.P.B.). Most EPROM burners will inly one type of EPROM. The A.P.B. system will program all commonly used 24 pin EPROMs by using special personality modules that adapt the unit to the EPROM. The following EPROMs are programmable: 2704, 2708, 2716, (3-volt) & (5-volt), 2732, 2508, 2516 and 2532. The versatility and power of the A.P.B. system means you're getting a PROM burning package with extensive capabilities. The price, $149.00, Insures you're getting the most cost-effective PROM burner on the market today. With a unique combination of personality modules and fc a & sophisticated software, A.P.B. will perform many operations impossible with conventional PROM burners. Mere's a brief lis! of some of A.P.B.'s capabilities: • Verify ROM is erased • Read ROM • Copy ROM • Copy between different ROM types • Program ROM • Partial programming and copies • Verify programming • Read or save ROM data on disk or cassette (Apple only) • Program directly from computer memory • Examine and/or modify working memory • Preset working memory The A.P.B. system is the most flexible PROM burner available. The A.P.B. system package consists of an interface card that plugs directly into an expansion slot*, a complete set of personality modules, software on disk and a detailed instruction manual. The software will run under NEWDOS/80, orTRSDOS™ for the TRS-80, and APPLE DOS™ or APEX for the Apple. If you're looking for a powerful, versatile and cost efficient EPROM burner, call APPARAT today. Dealer inquiries welcome. (303) 741-1778 •TRS-80 version requires the TRS-80 bus extender (Cat. # 1-025) or a separate user provided power supply and cable. TRS-BO. and Apple are trademarks of Tandy Coi and Apple Computer. Apparat, Inc. 4401 So. ramarac ParKw.iy Dei 10237 (303)741-1778 "Oft GO//YG SUPPORT FOR MICROCOMPUTERS' m Circle 124 on inquiry card. The Ultimate IEEE S-100 Memory Would... D BE NONVOLATILE holding data for up to eight years with the power off. □ RUN AT 6 MHZ without wait states. QRUN IN 8 OR 16-BIT systems with 8 or 16-bit wide data paths. □ HAVE EXTENDED 24-BIT ADDRESSING and bank select. □ HAVE DYNAMICALLY MOVABLE WRITE PROTECT AREAS to prevent accidental erasure or programs and critical data. □ GENERATE POWER-FAIL interrupts for orderly system shutdown & power failure recovery. ...Available Now from Dual Systems The Dual Systems CMEM memory boards combine high- speed CMOS memories with new 5-10 year lithium batteries to give you the nonvolatility of an EPROM board while retaining the instant writability of a high-speed read/write RAM. These industrial grade boards are ruggedly built and are burned-in for 200 hours. □ CMEM-32K, 32K-bytes... $895 □ CMEM-16K, 16K-bytes .... $795 □ CMEM-8K, 8K-bytes $695 OEM and Dealer pricing is available. Sales representatives in most metropolitan areas. system reliability/system integrity DUAL SYSTEMS CONTROL CORPORATION 1825 Eastshore Hwy., Berkeley 94710 (415) 549-3854 • TWX 910 366-2035 ml (empty), 1 ml of water, 2 ml, . . ., 100 ml. (Here the word "state" seems more natural than "node"; the latter usually refers to the graphic represen- tation of the problem.) Time as well as volume must also be quantized, which restricts us to adding or subtracting a given volume of water "at one time." We have 200 possible operators (some of which may be physically impossible for a given state): add 1 ml, pour out 1 ml, add 2 ml, . . . and so on up to add or pour out 100 ml. Finally, the goal node is any set of actions that brings the water level up to the marked line (wherever it happens to be). The state-space tree is large but finite; part of it is shown in figure 4. The 15-Puzzle Most of us have played with the 15-puzzle: fifteen numbered squares that slide around in a frame that allows four units on a side. The blocks are given in an arbitrary order and the object is to slide the blocks until, read by row, they are in as- cending order with the blank space in the lower right-hand corner. (Math- ematician/puzzlist Sam Lloyd made a lot of money betting people they couldn't solve the puzzle. It was a sure bet; with the starting position he used, a solution was impossible.) We will use the 15-puzzle to illus- trate various search methods. The BASIC program SEARCH (see listing 1) will implement different search techniques by changing only one subroutine. It will work for both the 15-puzzle and (for computers with less memory) the order-3 variation: the 8-puzzle. In this article we will use the 8-puzzle for illustration; even Text continued on page 86 ^0PEN= *\ (START NODEy exttwithX failure j PUT A (NODE AT TOP OF OPEN LIST) ONTO CLOSED LIST EXPAND A FOR SUCCESSOR NODES, GIVING S(i):(S(l),S(2) S(N)| TRACE POINTERS BACK, GIVING SOLUTION MERGE S(i)'s ONTO OPEN LIST (EXIT WIThA SUCCESS J Figure 5: The basic flowchart used to derive the SEARCH program of listing la. This flowchart is a modernized, generalized version of several given by Nils Nilsson in Problem-Solving Methods in Artificial Intelligence. The flowchart was written as struc- tured pseudocode (see listing lb) before becoming the BASIC program SEARCH. 78 September 1981 © BYTE Publications Inc Start talking business with your Apple COBOL is the most effective business language. Apple II is the most friendly business computer. CIS COBOL with FORMS-2 brings together the best features of COBOL and Apple to enable you to deliver the most effective, user-friendly applications. Business Programmers: Take the COBOL expertise you have acquired on big business mainframes, and use it on Apple II to create friendly applications that will talk directly to your users - where it suits them best, on their own desks. CIS COBOL's dynamic module loading gives you big application capability and the FORMS-2 source generator lets you build and modify conversational programs from visual screen formats, creating much of the code automatically. Application vendors: CIS COBOL with FORMS-2 steps up the pace for your development of the high quality professional application packages needed today. And creating them in COBOL makes them more maintainaPle. Over half the Apple II 's now being sold are going to business or professional users so demand for quality applications is growing fast, creating big business opportunities for you. Stability proven by the US Government. CIS COBOL has been tested and approved for two consecutive years by the US General Services Administration as conforming to the ANSI 74 COBOL Standard. Apple II under CP/M is included in CIS COBOL's 1981 GSA Certificate of Validation (at Low-Intermediate Federal Standard plus Indexed l-O and Level 2 Inter-Program Communication). Get your hands on CIS COBOL at your Apple dealer. Talk business with him now! Micro Focus Inc., 1601 Civic Center Drive Santa Clara, CA 95050. Phone: (408) 248-3982. MICRO FOCUS CIS COBOL with FORMS-2 for use on the Apple II with CP/M is an Apple Distributed Product. CIS COBOL and FORMS-2 are trademarks of Micro Focus. CP/M is a trademark of Digital Research. Apple II Is a trademark of Apple Computer. Circle 221 on inquiry card. BYTE September 1981 79 Circle 125 on inquiry card. Toughest Boards in Town... IEEE 696/S-100 NON-STOP CLOCK Keeps time with power off. Our industrial clock utilizes a new lithium battery for 3-9 years use. Easiest clock to program you'll ever see. Runs in all S-100 systems. □ Year, date, hrs, mins, sees, msecs. □ Uses new tSI CMOS chip. □ Vectored interrupts. D CLK-24 S250 A/D CONVERTER IEEE696/S-100 A1M-12 industrial standard module designed for industrial analog-to-digital use. □ Runs in all S-100 systems. D 32-channel, 16-differential □ 12-bit resolution/accuracy. □ 25-microsecond conversions. □ Instrumentation amplifier. □ BASIC program provided. □ AIM-12, S695 or S785 w/1-1000 gain transducer amplifier. D/A CONVERTER AOM-12 IEEE696/S-100 industrial level digital-to-analog (D/A) converter. □ 12-bit ± 1/2 L.S.B. accuracy over full 0-70°C temperature range. D Outputs 0-10, + 5, or ± 10 volts. □ Short circuit protection, all outputs. □ Switch-programmable for multiple boards. □ AOM-12, S575 VIC 4-20 Standard output for industrial control 4-20 mA D/A converter. Used in conjunction with the D/A board. VIC4-20, S445. DUAL 77 Data Acquisition and Control System- Built to industrial standards; designed for severe environments. BASIC language makes programming easy. Access to hundreds of sensors. Expandability to meet your increased needs. Nonvolatile memory. Power interruption recovery with automatic restart. DUAL 77 is economical; S5985 & up. system re/iabi/ify/system integrity DUAL SYSTEMS CONTROL CORPORATION 1825 Eastshore Hwy., Berkeley 94710 14151 549-3854 ■ TWX 910 366-2035 Listing 1: The SEARCH program, written in Applesoft BASIC for the Apple II. Listing la gives the program as implemented in BASIC. Listing 2, 3, or 4 must be added for this program to work. The subroutine that starts at line 9900 implements a given search method; all REM (remark) lines can be deleted to reduce program size. The diagnostic message printed by line 177 gives visual feedback on the progress of the program, although it does not give the correct value for the start node (node 1). The structured pseudocode in listing lb outlines the processes in SEARCH. Line numbers here refer to the "main line" of the program. i REM — SEARCH ALGORITHMS AND PGM FUR tS PUZZLE 2 REM — SRESG WILLIAMS, BYTE MAGAZINE, POB 132, HANCOCK NH 03419 5 REM ■I REM 3 REM LIST INS 1 100 DIM ni' L00) . 01 LOO) , R*<20) I 02 1 l-i A* ( 4 ) , E* (4, 4) , I- 1 ■ 'I , -i > , Z ' 1 6 > I 10 REM — INI I I ML I U PROGRAM 120 B0SUB 9500 I 25 REM I 30 Rl M L3S REM -- NEXT IS DO-WHILE LOOPs WHILE"0PEN" ARRAY NOT EMPTY AND EXIT I 40 REM — VAR I ABLE"" SEARCH" LS0 II El» - : "EX II " MIEN 495 158 Rl 11 ] 60 REM 165 REM — FIND N1=INDEX 0E LOWEST OPEN VALUE ! '0 60SUB 9000 175 IF OlNII = 99999 THEN 4 95 177 PRINT "177-EXPAND NODE "sNl;", ";0*(N1>;'\ VAL-" s (Nl > 1 BO RE M 185 REM — RUT NODE TO CLOSED! "SCRATCH" IN OPEN ARRAY J 137 REM — BY GIVING LARGE VALUE 190 C9 = C9 > I 200 0(N1) » 90000 + 0(N1) 220 REM 225 REM 230 REM —UNPACK BOARD POSN AMD GENERATE SUCCESSORS IN As 240 E* ■ MID* (0* INI), HI + 1,L2) 250 E9* = M T Dt ( 0* CN1 ) , H I. , 1 ) 255 BOSUB 9100 260 REM — NODE tt Nl IS PASSED AS ITSELF 265 REM — GENERATE SUCCESSORS 270 BOSUB 9200 275 REM 280 REM 285 REM — EVALUATE EACH FOR GOAL STATUS — Gl NODES WERE GENERATED 2B7 IF Bl > THEN 295 290 PRINT "290 — MO SUCCESSORS, N0DE";N1 292 (SOTO 470 295 G* = "NOT GOAL": FOR Ml = 1 TO Bl 300 REM — RETURN "GOAL" IF A* (Ml) IS GOAL NODE 310 BOSUB 9600 320 IF S* < > "GOAL" THEN 3130 330 El* = "EXIT" 340 REM — SAVE INDEX OF GOAL NODE 360 REM — FOLLOWING IS "ELSE" BRANCH OF 320:G* NOT = "GOAL" 370 REM — UNPACK BOARD TO E*,F* ARRAYS 380 E* = MID* (A* (Ml), HI + 1,L2) 390 BOSUB 9100 395 REM — EVAL H-HAT FCN FDR E*. RESULT IN Rl 400 BOSUB 99O0 410 REM — PUT A* (Ml) ON "OPEN" LIST 420 09 =09+1 430 0*(09> = A* (Ml ) 440 0(09) - Rl 450 NEXT Ml 460 REM — END OF DO-WHILE LOOP AT 150 4 70 BOTO 150 475 REM 480 REM 485 REM — THIS SECTION PRINTS EITHER SOLUTION OR FAILURE MESSAGE 495 IF GS < > "GOAL" THEN 540 500 REM --TRACE BACK SOLUTION 510 BOSUB 9800 520 60T0 550 530 REM — NO SOLUTION FOUND 540 PRINT : PRINT "NO SOLUTION FOUND" 550 PRINT "NODES ON OPEN LIST: " : 09 - C9 560 PRINT "NODES ON CLOSED LIST:";C9 570 END 8000 FOR I = 1 TO R9 8010 FOR J m 1 TO R9 B020 PRINT F*(I,J);: NEXT J B030 PRINT " ": NEXT I 8040 RETURN 8890 REM BB95 REM — SUBRTN TO CHECK IF NEW BOARD F* ( I , J > Listing la continued on page 82 80 September 1981 © BYTE Publications Inc Circle 108 on inquiry card. flMM. u B)MMWf v Vf *; ■|i ■ 11 n w v; >7 ■fsfwnp £>/£ tz The next generation of business software ti/ffifl WHAT'S IN A NAME^ We've changed the name ol oui product line. < )nginc)lly, products "Phoenix" because w sow the phocnx as n symbol ol quality, Unfortunately, a lot of ofne* < omporvf"i as well, ond there was some concern lhal the mortal become confused. Oui new name, PAIANTIR' (pronouns nd po/'anleef,', is ni loi us since it's oui corporate name ll cornos liom I.R.R lord of the Wings ond describes a bloc l< i ryital brill, a used lo see things at o distance. Whatever the name on the package, thp nor twain m ihi' \ changed. H is stil] the highest quality businow software* >< yout microcomputer. WORD PROCES5ING We know wok! processing. A year ond a ho" QflO I Dewgnei Software" wrote a well known word i >" " '■■••■• company. In the last 18 months we've learned about otln woni in a word processing package. PAlANHV"" Wo reflects oui experience. It 15 more powerful than othur w< packages you can buy ond con compete, feoiurp foi foi the best over for mic roroniputei have made it more accessible lot <'?*;• Hi u ■n ■ v^HWty $ BH ipi ffiftri£in' 1 HmfflPfr 1 ■ »«" ■ 1 i VL, H?BMK» 'mS ' -*> ('■"•-.( .k/A0 %'Wk ib kwla 1 HI ^^E&wFF* w%V ■Jh tfVi nd Pn ■< ••■ > '.i",| vv hove rata r raining Manual with beginning, Hy iillowinc) you lo walk cit your own i>(i'.iiM unci less intimi ACCOUNTING ntj packages [General Ledger, Ac ill ond Inventory) were designed by m mini arid mainframe computers, integral assembly language data automated posting to the General permits full screen data entry for node cosmetic enhancements poor ANUS" Act nunling aly includes a growing number of specific ilu cihon t"i' kagos We have < ompleted or scheduled foi completion ■d A. '.(■''., ffiionl I'm. e',Mn»|, Mail Management, Financial Pro|ec and UtYip Rilling loch package stands alone, but many also work in iiunrtion with othni PAIAN1IR" nackaaes, Foi example. Mail ikj we have given special attention to .■ni i'idev ribs which buttons to push, we lie ol rouiiiiiiq orincioles behind the pro Pesigoer Software HOUSTON mh -*5?!^jr ANUW " Word Processing ond accounting can do lau/out use //re Sonife In request more in/o/nui'ion. 3400 Montrose Blvd • Suite 718 • Houston, Texas 77006 (713)520-8221 • Telex 790510 • Source TCU671 LIE m I vvUi' Circle 257 on Inquiry card. If you have anything to do with small computers, you should be reading the Carl Helmers PERSONAL COMPUTER LETTER every month! You won't want to miss a single issue of the new Personal Computer Letter. . . a monthly publication of comprehen- sive studies on issues affecting design, implementation, and applications of small computer systems. The Personal Computer Letter is a journal compiled and edited by Carl Helmers, co-founder and first editor of Byte Magazine Here is valuable information in professionally prepared format about small com- puters, software, peripherals, trends in the industry, and new ideas. We accept no advertising and the information provided is available nowhere else. Written for executives, decision-makers, market strategists, product designers and authors in the small computer field, each 12 to 16-page issue contains analysis and design studies by many of the personal computer industry's foremost experts. For example, the current issue covers: Designing Appli- cation — Specific Documentation Tools: Let's Be Bold Where It Counts. Subscribe today. Mail the coupon with your check for $200 for the next 12 monthly issues. Sample issues at $25 per copy, applicable to a full year's subscription. — ^ ■■■ r-i - NORTH AMERICAN TECHNOLOGY, INC. Strand Building 174 Concord St., Peterborough, NH 03458 (603) 924-6048 □ Enclosed is my $200 check or money order for the next 12 issues of the Personal Computer Letter. D Enclosed is my $25 check or money order for a sample issue, applicable to subscription price. NAME ADDRESS CITY STATE ZIP Listing la continued: B900 Q3$ = "NOT DUPLICATED" 8905 REM — CHECK. THROUGH ALL. EXPANDED NODES 8910 REM — I.E., NODES WITH D(I)>=90000 S915 FOR I = 1 TO 09: IF 0(1) < 90000 THEN B930 8920 Fl» » MID* (Q*(I),H1 + 1,L2) 8925 IF F* = F.l* THEN S3* « "DUPLICATED" THEN B938 8930 NEXT I 8935 IF (33* = "NOT DUPLICATED" THEN 8938 13937 PRINT "8937 — CURRENT POSN IS DUPLICATE ***" 8938 RETURN B985 REM 8990 REM — SUBRTN TO FIND Nl SO THAT 0 IS SMALLEST 8995 REM 9000 SI = 99999: Nl = 1 9005 FOR I = 1 TO 09 9010 IF 0(1) > = SI THEN 9020 9015 SI = 0(1) :N1 = I 9020 NEXT I 9025 RETURN 9035 REM 9040 REM --PACK BOARD F*(N,N) TO STRING F* 9045 REM 7050 F* = " " 9055 FOR B = 1 TO R9 9060 FOR D = 1 TO R9 9065 F* = F* + F*(B,D) 9070 NEXT D 9071 NEXT B 9090 REM 9095 REM — UNPACK STRING E* INTO ARRAYS E*(N,N), F*(N.,N! 9100 FOR I = 1 TO R9 9105 FOR J = 1 TO R9 9110 G 1 = R9 * (I - 1 ! + J 9115 E*U,J) = MID* iN=l TO SI 9200 FOR I - 1. TO 5 9205 IF E9* = MID* 4 THEN 9315 9250 IF MID* (D*,S1,1) = 09* THEM 9.310 92S5 X2 * XI + X(S:l):Y2 = Yl + Y(S1) 9260 FOR I = 1 TO R9s FOR J = 1 TO R9 9265 F*< .(,,!> = ES(I,,1); NEXT J: NEXT I 9270 REM —EXCHANGE SQUARES (XI. Yl) AND !X2,Y2) 9272 IF X2 < 1 OR X2 > R9 THEN 9310 9273 IF Y2 < 1 OR Y2 > R9 THEN 9310 9275 F*(X1,Y1) = F*(X2,Y2) :F*(X2, Y2> = 9280 REM — PACK NEW BOARD AS NODE IN A*(N) 9285 GOSUB 9030 92B7 REM —CHECK FOR DUPLICATES IN 0* 9290 BDSUB S900 9295 IF 03* = "DUPLICATE" THEN 9310 9296 REM — NQDE=PO INTER BACK-i-DIRECTION+PACKED ARRAY 9297 A9 « A9 + 1 9302 GOSUB 9400 9303 A*(A9) = 0* + MID* = THEN 9440 9435 PRINT "SIZE ERROR IN 9400 — ABORT JOB": END 9440 IF (32 == THEN 9455 9445 FOR I = 1 TO 02 9450 P* = "0" + Q»i NEXT I 9455 RETURN 9485 REM 9490 REM — SUBRTN TO INITIALIZE PGM 9495 REM 9500 08 = 3: R9 = 3 9505 DATA -1,0,0,1,1,0,0,-1 9510 FOR I = 1 TO 4: READ X ( I ) , Y ! I ) : NEXT I 95:15 D* = "DLURB":!* = "URDL" 9520 E9* = "B" 9523 02* = "1.3426758": GOTO 9535 9S25 PRINT : PRINT "ENTER PUZZLE TO BE SOLVED IN "jR9 * R9;" CHARACTERS" Listing la continued on page 84 82 September 1981 © BYTE Publications Inc MULTIUSER ■ ■ .>'« fc ■ ■ lllllllllllllllll COMPUTER ON S-IOD BUS DESIGNED TO SATISFY A WIDE VARIETY OF APPLICATIONS. STANDARD FEATURES INCLUDE: CP IV] 2.2 OPERATING SYSTEM, B4K EXPANDABLE, BANKSE- MEMOBY,4MHZ ZBOA CPU WITH 4 SERIAL AND 3 PARALLEL PORTS, RELIABLE S" FLOPPY DISK DRIVES IN A STURDY ALL METAL CABINET. fpl $ 4900 MP M OPTIONAL. P.O.BOX 1847 SAN DIEGO, CA. 7343-J RONSON RD.SAM DIEGO, CA. C7 1<4J 57 1-697 1 Circle 305 on Inquiry card. Factory Direct ELIMINATE THE MIDDLE MAN! 1CA/ STATIC OlV RAM RAM 16 COMPARE OUR FEATURES! 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All utilize Solder Mask over Copper Technique for Higher Reliability! MIX AND MATCH FOR BEST PRICING. Include $3.00 shipping & handling per order. California residents include 6% sales tax. TERMS: Cash, checks, money orders or purchase orders from qualified firms or institutions. Pricing and availability subject to change without notice. International sales in U.S. funds only. COD'S include 25% with order. Quality Computer Parts P.O. BOX 743, DEPT. B1 CHATSWORTH, CA 91311 Telephone (213) 882-3142 •■•as ••••«••«»•«> •^•■••« 84 September 1981 © BYTE Publications Inc Listing la continued 9530 9535 9540 9545 9550 9552 9553 9555 9560 9565 9575 9580 9585 9587 9590 959) 9595 9600 9610 9615 9620 9625 9630 9635 9685 9785 9790 9B10 98 1 7 9820 9825 INPUT 02* IF LEN = R9 * R9 PRINT : PRINT "ERROR IN GOTO 9525 (.19 = 1:0(1) = Nl = Is GOSUB 9400 Q*(l) " 0* + "B" + 02* REM — ABOVE IB INITIAL THEN 9550 PUZZLE ENTRY - TRY AGAIN. ' .>; ' "84M 9845 98 ,( 9855 (lb) 120 150 170 190 270 287 295 310 320 330 400 420 450 470 495 510 540 IZATIQN OF "OPEN" LISTS, ARRAYS ' LISTS — C AND BOARD IS " OR "NOT GOAL GOAL' NODE hEM --- NEXT 18 INITIALIZATION OF "CLOSED C9 « HI = OB ■!■ 1 ;L2 R9 * R9 El* * "SEARCH" B* = "NO GOAL" RETURN REM — BUBRTN TO SEE IF REM -—RETURNS G*="S0AL 03* = "1.2345678. " IF R9 = 4 THEN (33* = " 123456789ABCDEF. " Q4* = RIGHT* ,L2) IF 03* ■ Q4* THEN 8* = "GOAL. ":N6 = 09 + ') REM — N6=IN0EX OF GOAL NODE; =09+1 BECAUSE 09 POINTS TO LAST REI'I — NODE FILLED; SEE 420-440 RE I URN REM REM REM O AND O* C* ARE BOTH EMPTY ■-8UBRTM TO TRACE BACK AND PRINT SOUM FROM 0* do while OPEN not empty and EXIT = no :A = top node in OPEN :put A from OPEN to CLOSED list :expand A giving successors A(N) if successors exist for each successor :evaluate successor for goal status :if node-is-goal : :set G = index of good node, GOAL = : :set EXIT = yes else : : calculate "value" of node : : :merge node and value into OPEN list : end if : :end of for-loop :end if endwhile if GOAL = yes :find solution by tracing nodes back from G :print full solution else :print failure message endif Yes 570 end program This Singl te Heart of the Microprocessor World's 'est Multi-User System... THE DISCOVERY MULTIPROCESSOR The dedicated power of this complete single board computer is provided to each user, making the DISCOVERY MULTIPROCESSOR unique among multi- user systems. 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(213)365-9661, outside California, use our toll- free number: (800)423-5659. Complete as shown. Vector CMA3A-20 with modules, 152.00 (1-9) September 1981 © BYTE Publications Inc Circle 375 on inquiry card. Text continued from page 78: with this 3-by-3 puzzle, the search tree grows rapidly. Elementary Strategy A certain form can be used to im- plement any search strategy. It assumes the following: two lists called OPEN and CLOSED, the former for nodes that have not been expanded (ie: that have not had all possible successors generated) and the latter for nodes that have been ex- panded; an algorithm for generating all legal successors; and an algorithm for determining whether or not a node is a goal node. One final algorithm, /, which implements the given search technique, provides a function that is used to order the members of the OPEN list to deter- mine which node is to be expanded next. The general algorithm is given in flowchart form in figure 5. It may be described as follows: 1. Place the start node on OPEN. CLOSED is empty. 2. If OPEN is empty, no solution exists; exit with failure. 3. Otherwise, let A equal the node at the top of the OPEN list. Take A off the OPEN list and put it on the CLOSED list. 4. Find all possible successors of A, named S(l), S(2),...S(N). 5. If there are no successors (N=0), go to 2. 6. Check the successors for goal status. If one is a goal, go to 8. 7. Calculate the /-values of each suc- cessor and merge the nodes into the OPEN list so that the OPEN nodes are sorted in ascending /-values. Also, place a pointer in each suc- cessor node that points back to the parent node A. Go to 2. 8. Trace the goal node through the pointers to the start node. This sequence, reversed, is the solution. 9. Exit with success. The method described above is ex- haustive and complete — that is, it always terminates. If it returns with an "exit with failure," it is because all nonterminal nodes have been ex- panded without finding a goal. Circle 377 on Inquiry card. — +■ comments: WCompared to the brands IVe used before/Verbatim Datalife is the best yet! ?? Sandy tiedeman Las Vegas, NV WNew Verbatim helped eliminate I/O errors on my Apple.?? Richard Adams Ft. Walton Beach, FL Datalife over any brand I ve ever used.?? Skip Piltz Overland Park, KS WMy experience with Verbatim diskettes has been excellent. IVe used several boxes over the past few months and they Ve all been error- free.?? Robert Roeder Las Vegas, NV WMuch stronger, better centering. A definite im- provement.?? Leroy LaBalle Marrero, IJK Wit has worked perfectly everytime!?? Richard Ruth WI like the thicker pro- tective cover.?? David Hendel Utitz, 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.?? Chris Otis Hoffman Fstates, II, WRuns quieter in the disk drive.?? Richard Cannova Los Angeles, CA They're our standard for quality.?? Bob Mills Mission, KS W Anything that prolongs the life of a diskette is a plus. Thank you Verbatim for an excellent improvement.?? Steve Toth Piscataway, NJ WOfthe 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 registration problem. Much more reliable than what I had been using.?? m Gary Sandler 90,000. 0$(N) Body of node N on OPEN list; see text. R$(N) Letters that, when arranged in reverse order, give the solution to the puzzle; see R1. X(N), Y(N) Increments in x- and y-position to cause a unit move in direction N, N = 1,2,3,4. E$(I,J) Representation of current node in expanded form; I, J vary from 1 to R9. F$(I,J) Scratch pad board used to generate successors to board E$(I,J). A9 Number of nonduplicate successors generated; see A $(N). C9 Number of nodes that have been tagged as closed, see O(N). D$ The characters of D$ represent the possible moves in the puzzle (down, left, up, right) and their orderings (eg: move 2 = MID$(D$,2) = "L" = left; move 5, B, stands for "beginning" and applies only to the start node). E9$ Direction used to get to current node from its predecessor. G$ Indicates whether or not A$(MI) is a goal node. G1 Number of successors generated before check for duplicate nodes. H1 (Index of first character of game in 0$(N)) minus 1; used to index the L9 characters of the board. L2 Number of characters in current board; =9 for order-3 board, =16 for order-4 board. N1 Index of O(N) giving smallest ordering value; node N1 will be expanded next. 07 Maximum size of arrays O(N), 0$(N). 08 Number of digits in 0$(N) pointer to its predecessor; set to 3, but, by expand- ing, can be used to process larger search. 09 Number of nodes (both open and closed) on 0$(N) list; next new node will be placed inO$(09 + 1). 09$ Direction that backtracks from current node to predecessor; see text. R1 Number of steps to solution of puzzle; see R$(N). Also, value returned by subroutine at 9900. R9 Rank of problem; set to 3 for order-3 board, to 4 for order-4 board. S1 Current smallest ordering value of array O(N), S1 = 0(N1). Table 1: Major variables used in the BASIC program SEARCH (see listing 1), 88 September 1981 © BYTE Publications Inc ±d I ATCZOM waqes TiT with CRTFORM CKlh.KM,'"; lin ms ( ,K a code < ll IS .l\.III.IHU R I T< >km makes all types i<> interface the program t< for all kinds ol people. Pascal, FORTRAN, BASK ( 1R I l( ikm is a (X)BOL I; easy to create, test, inouilv, and wulmm iikkIiIk alion lo rim <>n use (onus. The loi ins provide - .in over 95$ of the terminals ( ni- inici I.k c between programmers rently nn the market. ( !RTF< *at and end-users, such as secretaries, is currently available to run urn executives, and CPAs. CRTFokm theCP/M*. UCSD* and Apple assures that the programmer Will Pascal systems. providing end-users informal on how 10 enter data. If end-i cializiug in software develoj tools and technicjues. In ad< to GRTF< >rm, Statcom will s message in plain tngiisn wm< manager, an in your nearesi <. . i< i r< >rm cteatei call (512) 451-0221, or write ti Statcom, 5766 Balcones, Suite 202, Austin, Texas 78731. I, f i&JLA IB JKilC 1 aV'-'V.V HM| lv w * 4 ' 1 B^r^ * ^\*^ *s^y£mi*" m * . "* i. * j^-O ^vVKw \ 1 1 ssalH Programs that write programs. 1M C( H UH )F NATION i I II 1 1 lALCDNESSTE SOS AUSTIN TEXAS 78731 ■ KM .mil M.lli lllll -lie M llicil.i] H.M.ii, li S. | . J » I . \|i|i!r I I i aii Ki n.iiis i i v. other nodes; 0$(N) contains three things: the direction (U, D, R, or L) that transforms the predecessor of 0$(N) to 0$(N), an 08-digit pointer giving the node number of 0$(N)'s predecessor node, and a string of L2 characters that describes the "board" of node N in compressed form. (See figure 6 for further details.) • For any node not the start node, it is always possible to eliminate one of the legal "next moves." For example, if O(Nl) generates 0(N2) with a move of D (down), we can forget about generating the successor of 0(N2) that uses the move U (up), because the result will be the same board as in node Nl (which has already been expanded). In the SEARCH program, this is done by matching the "direction" of the cur- rent node in D$ with its correspond- ing letter in 1$ (1$ is a mnemonic for "inverse"); this second letter is then ignored in expanding the current node (see the subroutine of 9200). • It is possible for a series of moves to come back to a previously expanded node (this means that the state space for the 15-puzzle is a graph, not a tree). For this reason, the possible successors generated in lines 9240 through 9310 (subroutine 9200) are checked for duplication (subroutine 8900, used at line 9290). • Each of the four possible moves in the 15-puzzle is associated with a number between one and four (1 means the tile moves down, 2 in- dicates the tile moves to the left, 3 means the tile moves up, 4 means the tile moves right). Variables that use this numbering are X(N), Y(N), D$, and 1$. • Within the character representation board, the position with no tile is rep- resented by a period. • The SEARCH program was run on an Apple II with 48 K bytes of memory, and it should run without modification on the Commodore PET, the Radio Shack TRS-80 Model I Level II or Model III, or any other computer that uses Microsoft BASIC. The program is written so that all REM lines can be deleted without af- fecting the program's performance. Exhaustive Tree Searching The first method of systematically searching a tree can be described as follows: expand the start node, recording all the successor nodes (which are of depth one); if none of the nodes are goal nodes, expand all depth-one nodes, giving depth-two (6b) 0(10) = 5 0(23) = 3 O$(10) = "L 001 12345.786' 0$(23) = "U 010 12345678.' Figure 6: Representation of the 8-puzzle within the program SEARCH. A node is represented in the program as two variables. One is O(N), the ordering value of node N in the tree. The other is 0$(N), a string that has the following: • the direction used to get from N's parent node to N • the node-number of N's parent node (linking N back to the start node) • the board position for node N, written by rows Figure 6a shows part of a hypothetical tree; figure 6b shows how nodes 10 and 23 are represented within the program. Entry Point Use 8900 Input: Board F$(I,J), array 0$(N) Process: Determine if board F$(I,J) has already been expanded. Output: Q3$ = "DUPLICATED" or "NOT DUPLICATED." 9000 Input: Array 0$(N), 09 Process: Find smallest value in array. Output: Index N1, value S1 such that S1 = 0(N1) is smallest value in O(N). 9050 Input: Board F$(I,J) Process: Compress to a row-major string of characters. Output: F$ = String of L2 characters. 9100 Input: String E$ Process: Unpack string to board E$(I,J), F$(I,J). Output: Identical boards E$(I,J), F$(I,J). 9200 Input: Board E$(I,J), node number N1, direction E9$. Process: Generate up to three legal successors of board (which is derived from node N1), eliminate nodes already expanded, build full node (direction + pointer + board) for each successor. Output: Table of successors A$(N), A9. 9400 Input: Number N1, desired length 08. Process: Convert N1 to a string; strip off the leading blank, fill with leading zeroes. Output: String Q$ that "looks like" ISI1. 9500 Initialization routine; includes entry of puzzle to be solved. 9600 Input: Node A$(M1), rank of problem R9. Process: Extract compressed board from node, compare to goal node Output: G$ = "GOAL" or "NOT GOAL". 9800 Input: Goal nodeO$(N1). Process: Trace through pointers back to start node, collecting "direction letters" in R$(N). Output: Print (R$(R1), R$(R1 - 1), ..., R$(1)) - solution to puzzle. 9900 Input: Node 0$(M1) to be added to list, list O(N) (and other variables depending on method). Process: Adjustment of values in O(N); computation of ordering value for node M1, placed in R1, so that node M1 will be correctly inserted into OPEN list with a correct ordering value. Output: This is the subroutine implementing a given search algorithm. Table 2: A description of the subroutines used in SEARCH. 90 September 1981 © BYTE Publications Inc Circle 306 on inquiry card. our first name is Quality Our popular space game, Asteroids in Space, is now Meteoroids in Space, with hyperspace, autobrake, and autofire. This exciting arcade game can be played with or without game paddles. Diskette $19.95. Beneath Apple DOS This best-selling 170 page technical manual tells you everything you want to know about Apple's Disk Operating System. Book $19.95. LINKER Links and relocates assembled machine language programs. Works with any assembler. Diskette $49.95. USES Ji ili iji i 131 TT^T. i Beginners and experts both enjoy this Othello* playing game that outplays Hayden's Reversal. 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Prices subject to change CONSULTANTS CALL FOR INFORMATION AND PRICES ON The business computer that's HERE TODAY and HERE TOMORROW avoid obsolescence 8 & 16 bit (213) 454-2100 System Interface Consultants, Inc. Computer Specialists Established 1969 nodes; repeat this process until a goal node is found or until no unexpanded successor nodes can be found. In terms of the overall algorithm for tree searching (see figure 5), we implement this breadth-first algo- rithm by putting the newly generated successors on the top of the OPEN list — or, equivalently, by giving these nodes an O(N) value equal to their depth. Figure 7a shows the order in which nodes are expanded in a breadth-first search; note that all the nodes of depth n are expanded before any node of depth (ti + 1) is ex- panded. The subroutine to implement the breadth-first algorithm is given in listing 2a; its structured pseudocode (7a) equivalent is: 9900 value of node returned, Rl = value of parent O(Nl) + 1 In a breadth-first search, making the "value" of any node equal to its depth will cause all nodes of level n to be expanded before any node on level n + 1 (with "value" n + 1). In line 9900, the value 90000 is subtracted because, by this time, the parent node O(Nl) has been "marked" as being closed by adding 90000 to it. An alternate approach to tree searching is the depth-first algorithm. In this method, we repetitively ex- 18 4 (7b) (7c) Figure 7: Order of expansion by three exhaustive-search algorithms. The numbers to the right of each node show the order in which the tree is expanded. Figure 7a, the breadth-first search, is examined laterally, one level at a time; figure 7b, the depth-first search, takes a "walk" around the edges of the tree (as shown by the colored arrows); figure 7c, the limited depth-first search, combines properties of both types of search. These searches can be tried by installing the routines in listings 2,3, or 4 in the SEARCH program (listing 1). 92 September 1981 © BYTE Publications Inc Circle 343 on inquiry card. COME ON BOARD Learn about your microprocessor and develop its full power. You'll 1 ready for take-off in record time. MICROPROCESSORS: FROM CHIPS TO SYSTEMS by Rodnay Zaks A road map to the world of microprocessors. From fundamente concepts through recent developments and the future. This thorough treatment of microprocessing is logical, systematic and easy to read. 420 pp., 250 illustr., 5Vj x 8V2, Ref. 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It presents detailed descriptions of the architecture and function of the Z8000 and shows how it interacts with its family of support chips. An excellent source of sample programs. 312 pp., 124 illustr., 5V 2 x 8V2, Ref. C281 2nd edition $15.95 I TOI PLEASE SEND ME DPROGRAMMING THE 6502 DPROGRAMMING THE Z80 DPROGRAMMING THE Z8000 [^MICROPROCESSING: FROM CHIPS TO SYSTEMS NAME ^T^^ MAIL TO: ^F ^k. SYBEX DEPT. B91 r CVDCV 2344 SIXTH STREET L dTDEAi BERKELEY, CA 94710 PHONE ORDERS: INSIDE CA 415/848-8233 D SEND ME YOUR FREE CATALOG SYBEX TOLL FREE OUTSIDE CA 800-227-2346 ADDRESS, CITY STATE. ZIP. ADD D$1.50/book UPS or D75«/book 4th class mail or D$8/book overseas airmail (CA add tax) Total Amt. Enclosed OR CHARGE MY DV1SA DMC DAM E CARD NO EXP. DATE SIGNATURE ^m pand the successors of a given node (until no such node can be further ex- panded) before we start to expand the next node of the same depth; that is, we expand down the tree instead of across it, and are, in essence, generating and expanding the ter- minal nodes from left to right. Figure 7b shows the order in which tree nodes are expanded in a depth-first search; the subroutine to be inserted into SEARCH is given in listing 3. Its pseudocode equivalent is: 9900 value of node returned Rl = value of parent O(Nl) - 1 In a pure depth-first search, the node just generated should be ex- Listing 2: Subroutine to implement a breadth-first search strategy. 10 REM LISTING 2 9B90 REM — SUBRTN TO COMPUTE H-HAT; BREADTH-FIRST SEARCH 9895 REM — RESULT R1=VALUE OF PARENT+1 9900 Rl --= <0(N1) +1) - 90000 990S RETURN Listing 3: Subroutine to implement a pure depth-first search strategy. 9890 REM LISTING 3 9895 REM — ■ SUBRTN 10 COMPUTE H-HAT; PURE DEPTH-FIRST (SEARCH 9900 Rl = (D(N1) - 90000) - 1 9905 RET URN Listing 4: Subroutine to implement a limited depth-first search strategy. 9885 REM - LISTING 4 91390 REM — SUBRTN TO COMPUTE H-HAT BY LIMITED DEPTH-FIRST SEARCH 9895 REM — VALUE RETD=R:U LIMIT OF DEPTH=R3 9900 R3 = 3 9905 Rl = (0(M1) - 90000) - 1 99.10 IF Rl = - R3 THEN Rl =0 9915 RETURN panded before any other node already on the OPEN list from past expansions. A good solution is to let the "value" of the successor node be one less than that of the parent. Since the subroutine at 9900 chooses the node with the smallest O array value, this scheme forces the order of expan- sion just described. Putting the depth-first algorithm to work, we find that it seemingly generates nodes without end — but without making a practical attempt at moving toward a goal node (except when one happens to be on the left- most side of the tree). The handicap of the depth-first algorithm is that it will search to the end of a given branch before returning to shallower levels. Because most trees extend to a large, if not an unbounded, depth (whereas a goal node usually exists at a shallower level), the depth-first search is usually inferior to the breadth -first search: the former sweeps up and down the entire length of the tree from left to right, whereas the latter scans uniformly across each level of the tree from top to bottom, ■■■I Bteadbontd Kit shown with optional extra-cost parts. MBesssr'ft Now breadboard 50% faster with the 3M Whiz Kit. It puts high-quality Scotchflex Brand plugstrips, sockets and tools right at your finger- tips. So you can assemble a 20 l/C panel in less than half the time needed for hand-wrapping. There's no stripping. No soldering. No crimping. The kit's proven U-contact components let you use the same insulation-displacement technique for breadboarding that's used in pro- duction. Each contact's tin plated, so you save on cost. Bussing is fast— just one step. Wire inserted into the U-contact gives you — — Circle 358 on Inquiry card. usually first encountering a goal node at a shallow level. The limited depth-first algorithm (see figure 7c and listing 4) can be ex- plained as follows. Choose an ar- bitrary depth, n; do a depth-first search, rejecting (for the moment) all nodes of depth n or greater. If this does not turn up a goal node, do a depth-first search of the previously rejected nodes, rejecting all nodes of depth 2n or greater. Repeat this pro- cess until a goal node is found or the tree is exhausted. This is summarized in the pseudocode: 9900 R3 = depth of each "layer" of search 9905 value of node returned, Rl = value of parent O(Nl) - 1 9910 if "value" to be returned is equal in magnitude to R3 reset value to be returned = endif The "value" returned will be zero or negative. This search limits itself to depth R3 at a time by setting a node on the edge of the current level to the highest possible value, zero, so that it will be expanded only after the cur- rent layer has been expanded to the edge. The value R3 could be placed within the initialization subroutine of 9500. The limited depth-first search lessens the disadvantages of the pure depth-first search by providing for an eventual exhaustive search of the lower level of the tree. But it is also a compromise: if a goal node is located deep and on the left-hand side of a tree, this node will be more quickly found by the pure depth-first search than by the limited depth-first search. (In general, the effectiveness of both depth-first searches is extremely dependent on the left-right position of a goal node within the tree.) Notes on Experimentation We now have the tools with which to examine the exhaustive search algorithms. The BASIC program SEARCH (when fitted with the ap- propriate subroutine at 9900) will ask for the beginning puzzle (given row by row, with A through E repre- senting 10 through 15 in the order-4 version only, and a period repre- senting the space in the puzzle), list nodes as they are expanded and generated, and print out the solved puzzle. If you want to avoid typing in a puzzle every time you run the pro- gram, add the following lines: 9521 Q2$ = "< puzzle to be entered > " 9523 GOTO 9550 My observations and experiments are based on the sample 8-puzzles given in figure 8; a given puzzle will be referred to by its row and column number in this figure. Note that the row number is the number of moves in the solution of the puzzle and that a given puzzle is a subproblem of every puzzle below it and in the same column. Table 3 gives data on selected puzzles using the breadth- and limited depth-first algorithms. Remember that closed nodes are those that have been expanded for successors and open nodes are those that have been Text continued on page 98 ITBEATSTHECLOCK the equivalent of two wrapping levels. Double up in the contact and save four wrapping levels. CONVERT RIGHT TO PRODUCTION. Finished Scotchflex prototypes so closely match production quality, you're saved more time on redesigning and fine-tuning. The U- contact's less than % the height of an ordinary wrap post. So Scotchflex breadboards can be stacked on .600" centers for the most efficient use of space. You can reuse Whiz Kit's components up to 25 times. The hand tools are rugged, versatile and maintenance-free. The kit has its own storage tray. Expended parts can be easily replaced and stored. 50% FASTER FOR 25% OFF. Right now, 3M will send you a special cou- pon worth 25% off your first purchase of the new Whiz Kit. It's good at your Scotchflex distributor. 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MASTER ELECTRONICS INCORPORATED Authorized TRS-80 Dealer, Store # F-723 (3a) Puzzle Solution #Open #Closed Total (1,1) L 3 1 4 (1,2) U 3 1 4 (2,1) UL 7 4 11 (2,2) LU 6 3 9 (2,3) LL 4 3 7 (3,1) " LUL 9 8 17 (3,2) ULU 7 6 13 (3,3) ULL 10 9 19 (4,1) DLUL 12 11 23 (4,2) LULU 10 9 19 (4,3) RULL 16 21 37 (3b) ■ Puzzle Solution #Open #Closed Total (1,1) L 3 1 4 (1,2) U 3 1 4 (2,1) UL 11 12 23 (2,2) LU 8 7 15 (2,3) LL 10 9 19 (3,1) LUL 11 13 24 (3,2) ULU 9 7 16 (3,3) ULL 12 17 29 (4,1) DLUL 9 8 17 (4,2) LULU 7 6 13 (4,3) RULL 16 21 37 (3c) Puzzle Solution Depth (n) #Open #Closed Total (2,2) LU 2 6 3 9 3 6 5 11 4 8 7 15 5 12 11 23 (2,3) LL 2 4 3 7 3 6 5 11 4 10 9 19 5 12 17 29 Table 3: Experiments with SEARCH. In the breadth-first search (3a), # Open" refers to the number of nodes created but not yet expanded. "# Closed" is th i number of nodes that have already been expanded. Since the breadth-first algorithm searches uniformly down the tree from the start node, it is the most reliable of the exhaustive search m ethods. The limited depth-first search (3b), with depth n=4, shows that for all p uzzles on level four, the number of nodes that this algo) ■ithm generates s the same or less than the breadth-first search. By varying the cutoff depth, n, this a 'gorithm does a depth- first search in "layers" (see 3c), each layer being n nodes deep As n becomes greater than the number of moves in the solution (in this case, two), the algorithm more closely resembles a pure depth-first search in its inefficiency. 96 September 1981 © BYTE Publications Inc Circle 225 on Inquiry card. f + * MICRO-SCI SQUEEZES MUiWJ NOT YOUR POCKET w-.k ■ t '.% ' } ': 1 , 1 1 t I U . \ )•• ■• ) ». : ;:i: : .. ; ) ; f It f - t • ■ 1 fe Z80SoftCard. VERSATILITY PLUS A40's and A70's on the same com- puter. Micro-Sci's controller sup- ports one or two A40's, one Or two A70's or one of each. 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Text continued from page 95: generated but not yet closed (expand- ed); thus, the total number of nodes generated by an algorithm is the sum of its open and closed nodes. Also remember that the SEARCH program generates successors by expanding in the following order: down, left, up, right. Although this is less important for more advanced searches, it is extremely important Goal Node Row Number (1) One move away when analyzing exhaustive searches. Observations and Questions Please consider the following ques- tions before you read the answers on page 102. On the breadth-first search: • Note that the number of nodes ex- panded to get a solution varies with the directions used in the solutions; 1 2 3 4 5 6 7 8 1 2 3 1 2 3 4 5 6 4 5 7 8 7 8 6 1 2 3 1 2 3 1 2 3 4 6 4 5 4 5 6 7 5 8 7 8 6 7 8 1 2 3 1 3 1 2 3 4 6 4 2 5 5 6 7 5 8 7 8 6 4 7 8 1 2 3 1 3 1 2 3 7 4 6 4 2 5 5 6 5 8 7 8 6 4 7 8 (2) Two moves away (3) Three moves away (4) Four moves away Figure 8: A table of 8-puzzles used in the text. Ignoring the row with the goal node, each puzzle is referred to by its row and column numbers (eg: the rightmost puzzle in the row labeled "two moves away" is puzzle (2, 3). Notice how puzzles in the same col- umn are related to each other: each puzzle is a subproblem of the puzzle that appears directly below it. "downs" and "lefts" tend to make the solution shorter, while "ups" and "rights" make it longer. Compare the puzzle (2,3) with the puzzle at (2,1), and puzzle (4,2) with (4,3). • (Question 1) How is this tendency reflected in the number of nodes on the closed list? (Consult the text box, "Answers," on page 102.) • (Question 2) Then why does puzzle (3,2), with solution LUL, generate more nodes than puzzle (3,1), which has solution ULU? Aren't L moves ex- panded before U moves? • Notice that both puzzles (1,1) and (1,2) have the same number of open and closed nodes, even though the solution, L, in (1,1) precedes the solu- tion, U, in (1,2). This is because the SEARCH program generates all the valid successors of the node being ex- panded before evaluating them for goal status. • (Question 3) I noticed a curious fact while examining the solution of two puzzles, one of which is a subproblem for the other: the subproblem generates a node that the larger prob- lem does not. Run puzzles (2,1) and (3,1) using the breadth-first sub- routine and list the nodes generated. Where is the node in question? Why is it generated in (2,1) and not in (3,1)? 1 23 4 56 ©@ GOAL • 78 @© Figure 9: Solution of puzzle (3, 1) by the breadth-first algorithm. The tree is a partial tree carried out only far enough to reach the goal node (shown in the bottom row). The circled numbers in black indicate the order in which nodes are expanded to solve the puzzle. The node labeled B is the start node of puzzle (2, 1), a subproblem of puzzle (3, 1); circled numbers in color indicate the order in which nodes are expanded to solve puzzle (2, 1). 98 September 1981 © BYTE Publications Inc On the depth-first search: • You will probably find that you run out of memory (or patience) before you get a solution from the depth- first algorithm. This is because the algorithm first dives to the bottom of the tree, and that bottom is deep, even for a puzzle as small as the order-3 8-puzzle. Try experimenting with the depth-first algorithm, using the SEARCH program set to handle the order-2 puzzle. On the limited depth-first search: • Table 3b shows the results from the solution of the same puzzles, (2,2) and (2,3), using different cutoff depths (variable D3 in line 9900). Since both puzzles are solved in two moves, the cutoff depth simply deter- mines how far down the search will Text continued on page 102 SuperSoft's Gallery of CP/M Masterworks Programming Languages "C" FORTH FORTRAN IV RATFOR BASIC TINY' PASCAL Disk/Manual Only $200/20 $200/25 $250/25 $100/NA $200/25 $ 85/10 System Maintenance Diagnostics II Diagnostics 1 DISK DOCTOR $100/15 $ 75/15 $100/15 Utilities Utility Pack#1 Utility Pack #2 $ 60/NA $ 60/NA Text Processing TFS Super-M-List $ 85/15 $ 75/10 Software Security Encode/Decode II Encode/Decode I $100/20 $ 50/20 Intercommunications TERM TERM II $150/15 $200/15 Entertainment ANALIZA NEMESIS Dungeon Master (For use with Nemesis) $ 35/NA $ 40/NA $ 35/NA Miscellaneous Z8000 Cross-Assembler "C" Cross-Compiler (Z8000 Target) $500/25 $500/25 V. 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All software can be supplied on the following media: CP/M formats ... 8" sft sectored, 5" Northstar, 5" Micropolis Mod II, Vector MZ, Superbrain DD/QD, Apple 11 + 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 of Small Systems Services, Urbana. Illinois 24 hour express service available! SuperSoft First in Software Technology Puces suDiBct to change without notice Storwriter PRINTERS, MONITORS, DISKS Daisy Wheel Printer by C. 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WE SHIP THE SAME DAY ON MOST ORDERS 1 VISA' (714) 579-0330 • MAIL TO: 1251 broadway, el cajon, ca. 92021 AUTHORIZED APPLE SALES & SERVICE a-xsar-Mrs DIV OF COMPUTER METRICS INC DISK with CONTROLLER NEW DOS 3.3 $529 without . . . $445 Nearly Everything for Apple ;appkz h i6K computer APPLE II $1095 48K WE WILL MEET OR BEAT ANY ADVERTISED PRICES ON MOST ITEMS IF MERCHANDISE IN STOCK APPLE SOFTWARE ABM by Muse 19 Adventure by Mircrosoft 27 Alien Rain by Broderbund 19 Apple PIE 119 Apple Pilot 129 Apple-oids 25 Appleplot by Apple 59 Applepost Mailing List System 44 Applewriter Word Processor 65 Asteroid Field by Cavalier 19 CCA Data Mgmt 84 Data Factory by Microlab 129 Desktop Plan II 159 DB Master II by Stoneware 199 DOS Tool Kit 65 DOS 3.3 Upgrade 49 Dow Jones Portfolio Evaluator 45 Fortran by Apple 159 Hi-Res Football 33 Head-On 21 Integer Basic Cassette Demos 29 Orbitron 25 PASCAL Language System 459 Peachtree Bus. 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Date Signature Print Name Address City State Zip NETRONICS R&D Ltd. 333 Litchfield Road, New Milford, CT 06776 approximately equivalent in effi- ciency when n is only slightly larger than s. • (Question 4) In a limited depth-first search of level n on a puzzle with a solution of n moves, what are the two most important characteristics (in terms of the location of the goal node) that influence the solution time of the puzzle? Which is more important? • With limited depth-first searches of depth greater than the number of 135 426 (lO) 78 • 135 4-2 (jl) 786 453 Qg) 786 Figure 10: Solution to the puzzle (3, 2) by the breadth-first algorithm. The circled numbers to the right of each node indicate the order in which they are expanded. Nodes 8 through 13 (six nodes) are "open" (ie: they have not yet been expanded), whereas nodes 1 through 7 are "closed. " DEPTH = BREADTH-FIRST ■ = LIMITED DEPTH-FIRST (lib) DEPTH Figure 11: A comparison of search efficiency. The limited depth-first search always produces the same or fewer nodes than the breadth-first search, when the depth of the search is equal to the depth of the goal node. An example of the efficiency of the limited depth-first search is shown in figure 11a, where the breadth-first search (indicated in color) has produced more nodes. In figure lib, the two types of searches produce an equal number of nodes, using the same partial tree but a different goal node. The breadth-first search must always expand the entire tree to depth n — 1, whereas the limited version may not, depending on the location of the goal node. 104 September 1981 © BYTE Publications Inc Circle 379 on inquiry card. Take Your Cue From Vista . . When it comes to Apples, take your cue from Vista's A800 Eight-Inch Floppy Disk Controller. The A800 offers a cost-efficient approach to software compatible disk memory expansion for your Apple II© computer. The A800 Controller enables Apple II users to access up to five megabytes of online storage through conventional disk operating (DOS) commands. The Control and DMA Logic provides high speed (1 microsecond per byte) transfer of data from the disk drive directly to the Apple II memory without processor intervention. Plus, the Phase- Locked Loop Data Separator provides the ultimate in data reliability. AND THERE'S MORE. The controller is compatible with the most popular disk operating systems for the —mm.*. . i™ Apple II computer. It also interfaces to all Shugart/ANSI Standard Eight-Inch Floppy Disk K_ Drives. The A800 provides complete IBM for- 7» *» mat compatibility in both single and double- ts €M density modes. Sure Shot. w •• density modes. -.^ THE HOT SHOT AT A COOL PRICE. lv The A800 is reasonably priced at $595. A price you can't beat when you compare its r%f quality and performance. CALL YOUR SHOTS. Vista offers you a complete line of peripheral equipment to maximize the capabilities of your Apple system including: High capacity Mini- floppy Disk Drives, the Vista Music Machine 9 and the Vista Model 1 50 Type Ahead Buffer. In addition, Vista offers a line of advanced components fully compatible with the TRS-80" and S-lOO based " '■■ •. \ computers. IP llfei %/|^ #•-* Computer Tl9l(l Company 1317 E. Edinger Avenue Santa Ana, CA92705 (714)953-0523 Call Toll Free 800-854-801 7 © Apple II is a registered trademark of Apple Computers, Inc. " TRS-80 is a trademark of Radio Shack, A Tandy Co. rf* SS16K/IEEE 16K STATIC RAM BOARD 0NLY $ 179 95 Expand your system beyond 64K — add universal bank select option for only $20. 00 ifmiimimftffiiiiiifiiftfmffffflririW New: SS16K/IEEE RAM It's everything you need in a 16K static RAM board — at the lowst price you've ever seen. The SS16K/IEEE comes with all the high performance features listed below; And unlike obsolete-design RAM's (without bank select) you can add-on our universal software bank-selector system anytime, now just $20.00. This makes the SS16K/IEEE capa- ble of addressing 2,048 different banks. You can add memory beyond the 64K limit. You can expand to a multi-terminal system. FEATURES OF SS16K/IEEE • • Low-power 2114's • All inputs and outputs meet the proposed IEEE standards for the S100 bus. • 4.0 MHz operation. • Schmitt trigger buffer on all signals for maximum noise reduction. • Addressable on 16K boundaries, 0-64K, dip switch selectable. • Phantom option, dip switch selectable. • PWR/MWRITE option, dip switch selectable. • Glass epoxy PC board with gold-plated contacts and double-sided solder mask. • Fully socketed. • Four separate regulators, for maximum stability. WITH BANK SELECT OPTION (now just $20.00) YOU ADD THIS: • Software bank selector featuring a universal decoder works with Cromenco, Alpha Micro, Netronics, most other systems, or your design. On-board dip switches: Bank Select Enable, Reset Enable, Reset Disable, Port Address, Port Data. • LED Indicator to display status. 10-DAY MONEY-BACK TRIAL: Try a fully wired and tested board for 10 days — then either keep it, return II for kll, or simply return it In working condition. Continental U.S.A. Credit Card Buyers Outside Connecticut: TO ORDER CALL TOLL FREE 800-243-7428 From Connecticut or For Assistance: (203) 354-9375 Please send (he items checked below: SS16K/IEEE without bank select: □ Kit $179.95* D Fully assembled, wire & tested $199.95* SS16K/IEEE with bank select: D Kit $199.95* □ Fully assembled, wired & tested $229.95* □ SS16KAEEE bank select option $20.00* "Plus $2 postage & insurance ($5.00 Canada). Connecticut resi- dents odd soles tax. Total enclosed: $ □ Personal Check □ Money Order or Cashier's Check □ VISA □ Master Card (Bank No. )! . Exp. Date . Signature . Print Name City fe^NETRONICS R&D Ltd. ■IKh 333 Litchfield Road, New Milford, CT 00776 .ItDlllitluliiiliialliiiuiiiiamiNiin DEPTH AREA (o) Figure 12: A comparison of four exhaustive searches. Given the partial tree with goal node on level six, the four lines A, B, C, and D delineate the nodes expanded by the following searches: A limited depth-first search, with n=s = 6 B limited depth-first search, with s an even multiple of n (s = 6, n=3) C breadth-first search D limited depth-first search with s not an even multiple of n (s=6, n=4) The worst case for the limited depth-first search, given by D, expands more or fewer nodes than the breadth-first search, C, depending on whether area a or area b has more nodes. moves in the problem solution (n > s), the number of nodes ex- panded increases with the difference between the two (see the results of table 3b). • When the depth of the search is less than the number of moves in the solu- tion (rc < s), two cases occur. If s is a multiple of n, the efficiency of the search is between that of a breadth- first search and a limited-depth search with n = s (as illustrated in figure 12). If, however, s is not a multiple of n, the result is mixed. The depth-first search will go several levels deeper than the level of the solution and may be better or worse than a breadth-first search depending on the number of nodes expanded past level s and the number of nodes expanded in the breadth-first search that are not ex- panded in the limited depth-first search (see figure 12). • (Question 5) A depth of one (n = 1) gives a special case of the limited depth -first search. What is another name for this search? Conclusions We've covered quite a bit of material in this article, including an introduction to tree- and graph- searching terminology, a definition of the finite-state representation of a problem, the general-purpose search algorithm implemented in the BASIC program SEARCH, and three exhaus- tive-search algorithms. In most cases, a breadth-first search is the best of the three, but in some cases it can be im- proved upon by the limited depth- first search. Part 2 will deal with heuristic algorithms that estimate the "worth" of a given node in order to arrive at a guaranteed solution without perform- ing an exhaustive search. ■ References 1. Nilsson, Nils J. Problem-Solving Methods in Artificial Intelligence. New York: McGraw-Hill, 1971. An excellent book on all aspects of this subject as well as the related topics of problem reduction, theorem-proving, and the searching of game trees. 2. Winston, Patrick Henry. Artificial In- telligence. Reading MA: Addison-Wesley, 1977. A good overview of artificial in- telligence with one section devoted to tree searching. 106 September 1981 © BYTE Publications lnc Circle 274 on inquiry card. 6 Brand New Books from Osborne/McGraw Hill Interfacing to S-100 (IEEE 696) Microcomputers by Sol Libes and Mark Garetz This book assists S-100 users in expanding the power and utility of their systems. It describes the S-100 bus with unmatched precision and detail. Various chapters describe its mechanical and functional design, logical and electrical relationships, bus intercon- nections, and bussing techniques. Both parallel and serial interfacing are described as well as interfacing to RAM, ROM, and the real world. Additional chapters discuss D/A and A/D conversion, inter- rupts, timers, and direct memory access. #37-3 $15 D Microprocessors for Measurement and Control by D.M. Auslander and P. Sagues Learn to design mechanical and process equipment which use microprocessor based "real time" com- puter systems. This book shows you how, and, using case studies, builds and explores problems of in- creasing complexity ? .-The. book presents plans for prototype systems, allowing readers (even those unfamiliar with machine or assembly language) to initiate projects and carry them through to com- pletion. #57-8 $15.99 □ CBASIC™ User's Guide by Gordon Eubanks, Adam Osborne, and Martin McNiff The CBASIC language j*iay be the most advanced version of BASIC yet "created. Like Pascal, CBASIC requires no line numbers and lends itself to highly organized, structured programs— programs that are readable, modular, and easier to change. CBASIC is as easy to learn as BASIC and contains convenient file handling facilities, making it very useful for many business applications. It may be the only computer language you'll ever need to learn. This guide was co-authored by Gordon Eubanks, the creator of CBASIC. It is not only a self-teaching textbook, it is the definitive reference on the CBASIC language. : , \ #61-6 $15 D L \ \ ATARI™ Some Common BASIC Programs TRSW level II Some Common BASIC Programs Two new editions of Osborne's celebrated collection of 76 useful and informative programs in Math, Finance, and Statistics. These programs will trans- form your Atari 400 or 800 or your TRS-80 computer from a plaything into a real workhorse. The programs are clearly documented to serve as a valuable instructional aid in learning BASIC. ATARI version: #53-5 $14.99 D TRS-80 level II version: #54-3 $14.99 □ Science and Engineering BASIC Programs edited by John Hellborn \ s — ~jT 50 programs with a wide range of scientific and engineering applications - Clearly documented and easily adapted for any popular microcomputer - This book is an indispensible tool for any scientist, engineer or student. Included are programs for interpolation, regression, data analysis, roots of polynomials, matrix operations, and linear equations. You'll also find programs for eigenvalues and eigenvectors, differential equations, Fourier analysis, Structural analysis, thermodynamics, and many others. #63-2 $15.99 D eft Make check payable to: *^ OSBORNE/McGraw-Hill 630 Bancroft Way, Berkeley, CA 94710 Dept. B19 Name. Address City/State/Zip . Plus □ .75/item 4th class D $l.50/item UPS D $2.50/item Air Mail □ $10.00/Overseas (California Residents add applicable tax.) □ Please send me your free catalog. Total amount enclosed $_ Signature . or charge my CI Visa G Mastercharge Card #. Phone: (415) 548-2805 TOLL FREEr80O-227-2895 outside California Book Review Turtle Geometry by Harold Abelson and Andrea A diSessa MIT Press, Cambridge MA, 1981, 478 pages, S 20.00 Reviewed by W Lloyd Milligan 8604 Maywood Dr Columbia SC 29209 Imagine four turtles, each sitting at one corner of a square. At the same moment, each turtle begins to crawl in a clockwise direction toward its nearest neighbor. They continue crawling at the same speed toward one another until they meet. How long is the path traveled by each tur- tle? The solution to this well- known problem — that the path equals an edge of the square — is reached most easi- ly by working from the turtle's point of view. A tur- tle is a small creature that in- habits a computer's graphic- display screen. It has the ability to move forward or backward a specified distance and to turn in place clockwise or counterclockwise through a given angle. Distances and angles are arguments in turtle commands. Just as straight- edge and compass are the basic tools of traditional geometry, so the turtle is the implement of turtle geometry. Turtle Geometry, by Harold Abelson and Andrea A diSessa, discusses using the computer to explore mathe- matics. The authors make a persuasive case for their idea that compared with tradi- tional methods, the computa- tional approach encourages mathematical exploration at an earlier stage of learning. The turtle leads the learner on quite a different mathe- matical journey than does traditional geometry. The earliest ideas presented in this book later are found to bear important relationships to topological concepts. We first learn of the distinction be- tween intrinsic and extrinsic properties — intrinsic proper- ties are those that do not re- quire a frame of reference for their expression. A second important distinction con- cerns local versus global rep- resentations. Circles are con- structed locally, meaning that the turtle does not know about the rest of the plane when making a small piece of a circle. Many of the turtle's constructions are both intrin- sic and local. Remember that the turtle can turn in place through any specified angle. If he keeps track of his turning by adding all clockwise turns and sub- tracting all counterclockwise turns, he immediately discovers the Closed-Path theorem: The total turning along any closed path is an integer multiple of 360 degrees. The approach of turtle geometry is empirical. You obtain a result like the Closed-Path theorem, then try to improve it, exploring its consequences for various kinds of paths. Before long you have made a new dis- covery, perhaps in a different branch of mathematics. It is a tribute to the richness of tur- tle geometry that by the end of the first chapter you are studying the Euler function and Fermat's "Little" theorem, both number- theoretic ideas. Because the turtle is an animal, it is only natural to explore turtle movement as behavior in response to con- trolling stimuli. Much can be learned by programming the turtle to model various types of forced movement, such as movement toward or away from stimulation. (For ex- planations of forced move- ment, see Orientation in Animals by G Fraenkel and D Gunn. Dover, 1961.) You can even set up experiments in which the turtle is respond- ing to information from more than one sense simultaneous- ly. The turtle can be used for modeling patterns of growth found in nature. The princi- ple of uniform growth leads to the shape of an equi- angular (logarithmic) spiral. Many other fascinating designs, such as the spiral shapes found in seashells, arise from invoking simple turtle procedures recursively. (See On Growth and Form, by D Thompson. Cambridge University Press, 1961.) The book provides a painless introduction to vec- tor methods. The brief excur- sion into linear algebra is the book's only "corruption" (by Cartesian analytic geometry) of turtle geometry, and it is both appropriate and worth- while. You learn here how to represent three-dimensional objects in two dimensions. Parallel projection is presented first, then perspec- tive projection. Anyone who appreciates arcade games or is interested in their design will find this chapter en- lightening. The geometric bases of changing perspec- tive, zooming, and the like are explained. Any computer with good graphics may be used to im- plement turtle geometry. (A commercial version is avail- able for the Apple.) A well- structured language such as Pascal is desirable, but not essential, to implement the turtle routines. Inevitably, the turtle escapes from the plane. Tur- tle spherical geometry is the first nonplanar generaliza- tion. A beautiful local defini- tion of geodesic is developed: A turtle line is an equal-strided turtle walk. Equal-strided means the tur- tle's left and right sides move equally. The beauty of this definition is that it applies to any surface. Remember, the total turning around a closed path is an integer multiple of 360°. As it turns out, the tur- tle can execute a closed path on nonplanar surfaces with a net 360° change in heading, but a total turning not equal to 360°. The discrepancy can be detected intrinsically. The concept, called angle-excess, gives rise to the important property called curvature. Further exploration brings us to the domain of topology, where we encounter theorems such as, "Any one- holed torus (doughnut- shaped surface) has zero total curvature." Articles Policy BYTE is continually seeking quality manuscripts written by indi- viduals who are applying personal computer systems, designing such systems, or who have knowledge which will prove useful to our readers. For a more formal description of procedures and requirements, potential authors should send a large (9 by 12 inch, 30.5 by 22.8 cm), self-addressed envelope, with 28 cents US postage affixed, to BYTE Author's Guide, POB 372, Hancock NH 03449. Articles which are accepted are purchased with a rate of up to S50 per magazine page, based on technical quality and suitability for BYTE's readership. Each month, the authors of the two leading articles in the reader poll (BYTE's Ongoing Monitor Box or "BOMB") are presented with bonus checks of $100 and S50. Unsolicited materials should be accompanied by full name and address, as well as return postage. 108 September 1981 © BYTE Publications Inc We're our own I i When we designed a line of business systems for eye care professionals, we set the same high standards that established our reputation in the field of sophisticated, computerized visual field testing equipment. Our customers expect functional design, precision engineering, and quality components— so when we encountered problems with floppy disk quality and availability, it was natural that we put our own manufacturing expertise to work in solving the problem. SYNEMED FD4 8" dual-sided, dual-density floppy disks are superior to any we could buy— and too good to keep to ourselves! Available for immediate delivery from stock and competitively priced, the FD4 offers RX01/02* compatible, two-megabyte floppy disk capacity for the LSI-11* Q-BUS* • Long disk life achieved by air-damped head loading • High reliability NEC drives • Single or double sided, single or double density, all transparent to your software • Patches for RT-11* DY handler enable full 1962 block capacity per disk • Controller includes additional bootstraps for RL01/2* and RK05* • Standard size— simply plug into existing equipment Mail the coupon today for more information on the SYNEMED solution to your floppy disk problems. I J I I r — I Synemedjnc. 1215 Fourth Street Berkeley, California 94710 415/526-5330 "Trademark of Digital Equipment Corp. □ Please send me more information on the FD4. D Please have your representative contact me. Name - Street . State- -Zip_ l_ Circle 397 on inquiry card Xity_ -Tel. No.. BYTE September 1981 109 Book Review. Any surface in three dimensions can be deformed into a piecewise-flat surface. Piecewise-flat means, simply, that the surface is made of flat pieces joined at the edges. If the edges are straight, then all of the curvature is concen- trated in the vertices. Piecewise-flat surfaces are easily represented in a com- puter program by an atlas which specifies all matching edge pairs by their face and edge numbers. Since a piecewise-flat deformation preserves all the topological properties of a surface, these properties can be studied as they are exhibited in this special case. For example, an important theorem, Gauss- Bonnet, states that the total curvature of any closed sur- face is: 2rr( V-E+F) where V is the number of ver- tices, £ the number of edges, and F the number of faces. The turtle's wanderings take him, finally, to the do- main of curved space and general relativity theory. Gravity as a property of geometry is presented in a parable about a turtle who lives near the north pole of a sphere. He constructs a two- dimensional Euclidean model of his experience. Inevitably, the turtle encounters various strange problems with his model. He eventually over- comes his difficulties by postulating a force which acts everywhere locally. The force is called "demon- turning." Traditionally, mathematics has shunned the computa- tional approach. The main thesis of Abelson and diSessa's book is that ex- perimentation using a com- puter stimulates mathe- matical discovery. The thesis is certainly true of turtle geometry, and one suspects it applies to many other areas of mathematics. Reading this book with the help of a good graphics computer system, you are sure to discover new and interesting math. Turtle Geometry is a serious effort to blend the computer with mathematics. It would serve as an excellent textbook or self -study guide. Perhaps it will also serve as a model for other efforts to bring the computer and mathematics to fruitful collaboration. ■ BYTE's Bugs Corrected Price In the June 1981 BYTE, Ax- lon Inc's 8-slot bus expansion board was incorrectly priced. (See page 420.) The board costs $895. The company has also released new pricing on the RAMCRAM memory module. It now costs $225. Blasted Bugs In the August 1981 BYTE "Software Received," the price for Budgeco's Raster Blaster was incorrectly listed. The correct price is $29.95. We apologize for the mistake. Super Simple Bug An integrated circuit was incorrectly labeled in James Nicholson and Roger Camp's article "Build a Super Simple Floppy-Disk Interface, Part 1." (See the May 1981 BYTE, page 360.) In Figure 4b on page 372, IC9 should be numbered 74193. The pin numbers are correct as shown. Color PEEKS Stan Miastkowski's article "Extended Color BASIC for the TRS-80 Computer" has been the focus of much atten- tion. (See the May 1981 BYTE, page 36.) It seems that the system does indeed in- clude a PEEK function, con- trary to what was previously printed. The author replies: / admit that I goofed. For BYTE to run an article on Ex- tended Color BASIC at about the time it became widely available in Radio Shack stores, the company pro- vided me with one of the first production models and a rough draft of the documen- tation. The rough manual had a list of differences, one of which showed that PEEK was not available in the nonextended model of the TRS-80 Color Computer. It was, however, available by the time the manual reached its final stages, but that was too late for inclusion in the article. Last One Out In John Sauter's article "Faster BASIC for the Ohio Scientific" (May 1981 BYTE, page 236), an error was discovered in listing 3 on page 240. The last line, an "INY", should be omitted — it is not part of the "ROR A" macro. For those using Microsoft's KIM or TIM BASIC, the new code would be as shown in listing 1. Another bug was found when using the 5-inch disk version. The code to be patched is on track 04, not 03 as published. Also, when us- ing smaller disks, the top memory should be set at hexadecimal 4200 as opposed to hexadecimal 47FF for the larger 8-inch disks. ■ Listing 1 $37C2 B0 18 BCS $37DC $37D1 76 02 ROR $02, X $37D3 76 03 ROR $03,X $37D5 76 04 ROR $04,X $37D7 68 BLA $37D8 6A ROR A $37D9 C8 INY $37DA DO E8 BNE $37C4 $37DC 18 CLC $37DD 60 RTS ($37DE through $3801 now unused) $38C3 66 73 ROR $73 $38C5 66 74 ROR $74 $38C7 66 75 ROR $75 $38C9 66 76 ROR $76 $38CB 66 BD ROR $BD $38CD 98 TYA $38CE 4A LSR $38DF DO D6 BNE $38A7 $38D1 60 RTS (S38D2 through $3903 now unused) 110 September 1981 © BYTE Publications Inc 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 236 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. CONSUMERS PRODUCTS Microsoft Consumer Products, 400 108th Ave. N.E., Bellevue, WA 98004. (206) 454-1315 1 I I 1 1 J ■ Photo 1: Advanced TIROS-Class Weather Satellite. Used in military and civilian versions, the TIROS satellites have two on-board computers. One Step Forward — Three Steps Backup Computing in the US Space Program A special tension surrounds the de- velopment of a computer system for use as the main computer aboard a spacecraft. On one hand, such a com- puter must be able to perform com- plex operations. On the other, since the first extraterrestrial service call by a field engineer is yet to be made, an on-board computer system must do its work with absolute reliability despite the most demanding envi- ronmental conditions. And by the time a computer's reliability has been proved beyond a doubt, more effi- cient computers have appeared on the market. It's almost as if the same pro- cess that proves a computer's reliabil- Patrick Stakem c/o Interface Technology POB 745 College Park MD 20740 (301) 490-3608 ity also ensures that the computer will be obsolete before it flies. Developing a main on-board computer is both a battle to prevent a catastrophic failure and a race against obsoles- cence. The advent of the space shuttle (known more formally as the Space Transportation System) will soon en- hance the requirement for reliability on orbital missions. Moreover, the shirt-sleeve environment of Spacelab will prove an opportunity to use off- the-shelf microprocessor systems to support scientific experiments. But space-rating — establishing the fitness of hardware for use aboard a space- craft — will remain a severe test, espe- cially for computers that control life- critical and mission-critical systems. In this article, I'll first discuss the requirements of space-rating. Then I'll describe the tasks that a main on- board computer must perform and some of the capabilities needed to perform those tasks. I'll go on to dis- cuss the problems of providing 112 September 1981 © BYTE Publications Inc Circle 325 on inquiry card. fi available now from stock Ultra Fast - 100 nsec. chips Fast access allows memory management manipulation without wait states. 8/16 - 8 or 16-bits wide Dynamically switches data path width per IEEE Standard. Low Power Typical power consumption less than 2 amps for active board. Less for power down boards. Extended Addressing 24-bit IEEE addressing allows 16-megabyte range. Single shunt changes to 16-bit addressing. Fully Static No clocks, no refresh required for easy DMA use. Special Features Any 4K block can be disabled. Or, can disable everything above or below any 4K boundary. Available in 16K increments for OEM quantities. $1,295 100 nsec. Chips - Qty. 1-9 OEM & Dealer prices also available. i_^J Jl^lI Il^J It ^ ii li ^ il ..00000000 00000000 00000000 00009000 TO ORDER: May be ordered through your local computer store or factory direct. Personal checks, CODs, VISA and MC accepted from within USA. 10-day return privilege on factory orders. Shipping paid by SCP on prepaid USA and Canadian orders. All boards fully assembled, guaranteed one year. ^COMPUTER 1114 Industry Dr. Seattle WA 98188 Information Hotline: 206/575-1830 Send more information: ( Name Company Address _ City .State. .Zip. ground support for on-board soft- ware. After a glance at the historical de- velopment of on-board computers, I'll look at some devices now in use. Finally, I'll describe applications of microprocessors in noncritical func- tions aboard spacecraft. (Yes, there will soon be an Apple in orbit.) Throughout the article, I will confine my comments to civilian spacecraft of the United States. Space-Rating Equipment and software that must operate for long periods unattended in the difficult environment of space must be very reliable. Space-rating is the process that demonstrates the reli- ability of equipment for use on space- craft. The process requires careful testing of parts, components, assem- blies, modules, and software. Space- rating standards are stricter than specifications for military equipment. Here are a few of the things that a main on-board computer in the mid-1980s must be able to do: • withstand repeated heating and cooling from +50° Celsius to -10° Celsius • function despite exposure to mecha- nical shocks, electromagnetic distur- bances, high-energy particles, and radiation • withstand forces from to 30 gravities • perform calculations on the level of evaluating 1300 long time-series poly- nomials per second to 32 bits of preci- sion • undergo intensive use for periods of several years without experiencing a single failure Although space-rating standards of reliability are always stringent, they depend to some extent on the kind of mission for which the spacecraft is in- tended. Mission Classes Missions usually fall into one of three classes: manned missions, planetary-probe missions, and un- manned earth-orbiting missions. Manned missions require the highest standards of reliability. When an astronaut's life is at stake, there is no room for failure. This principle is reflected in the record of the Apollo program: as a result of 2000 man- years of development and testing, there were no flight-critical errors of spacecraft software (see reference 8). The most common way to establish reliability in spacecraft equipment is to build in redundancy. The Shuttle Orbiter vehicle, for example, has five general-purpose computer systems to control all aspects of its operation. In of a rule that the Shuttle Orbiter will not be allowed to approach "dead" spacecraft. Unless telemetry indicates that an unmanned satellite still has ef- fective attitude-control and a certain level of stability, the Orbiter crew (and the extremely expensive Orbiter itself) will not be committed to ap- proach the satellite. In addition, any satellite intended for launch as a shut- tle payload must pass the same strin- gent requirements as a manned space- craft. Although no lives are at stake in their use, planetary-probe spacecraft also impose stringent requirements on on-board computer sysems. The long Photo 2: Shuttle Orbiter mounted on transport aircraft. The Orbiter has five on-board computer systems, configured to provide as many as three levels of backup in critical situations. Two chase planes are visible. certain critical operations, four of the five systems will perform the same task, providing three levels of backup. More recently, concern for the lives of astronauts has led to the adoption flight times to distant targets, the hostile environments traversed, and the impossibility of retrieval or repair all increase the demands placed on equipment. Planetary -probe space- craft are very much on their own. 114 September 1981 © BYTE Publications Inc Circle 267 on inquiry card. THE NEW FLIP/FLOPPYDISK with twice the byte OMNI is pleased to bring you a reversible 5 1 /4" mini diskette.. .the FLIP/FLOPPY DISK. Now you can record on both sides tor twice the storage capacity ot a single sided disk. And you'll be able to do it tar more economically, too! Each OMNI FLIP/FLOPPY DISK incorporates all of the quality features you'd expect from the very best single sided disk. • Two recording surfaces • Two sets of WRITE ENABLE notches • Two index holes • Reinforced HUB RINGS • Certified error-free operation at more than twice the error threshold of disk drives • Over 12 million rated passes without disk related errors or significant wear, for extra long life operation • Available in Soft or Hard sector • Compatible with most 5]4" disk drives including APPLE, TRS-80, PET, OHIO SCIENTIFIC, ZENITH, NORTH STAR, and many more. OMNI Resources 4 Oak Pond Avenue • Millbury, MA 01527 • 617-799-0197 Call TOLL-FREE: In Mass. 1-800-252-8770 Nationwide 1-800-343-7620 INTRODUCTORY OFFER Order the OMNI FLIP/FLOPPY DISK at this special introductory price: FivePack...$21.00 Equivalent to ten single-sided disks. Ten Pack.. ..$40.00 Equivalent to twenty single-sided disks. Please send me the following OMNI FLIP/FLOPPY DISK(s) Five Pack(s) @ $21 .00 each = $ Ten Pack(s) @ $40.00 each = $ Library Case(s) @ $3.00 each = $ Shipping and handling $ TOTAL $ D Check made payable to OMNI RESOURCES □ Mastercard Account Number □ VISA/BankAmericard Account Number Credit Card Expiration Date / Name. 1.50 Address . City D C.O.D. State. .Zip. Phone Number L ) Authorized Signature Massachusetts residents add 5% sales tax Money back guarantee if not completely satisfied Copyrights 1981 by OMNI Resources The distance between spacecraft and earth is often so great that radio signals require long periods to travel between the two. When the target is one of the outer planets, communica- tion may take more than a half hour each way. By the time the ground sta- tion receives a message indicating a problem aboard the spacecraft, too little time may remain to send mes- sages intended to correct the prob- lem. The design requirements for computer systems aboard planetary- probe spacecraft are perhaps an order of magnitude beyond those for sys- tems aboard spacecraft operating near earth. Most spacecraft carry out un- manned earth-orbiting missions. These missions may have either near- earth orbits or synchronous-altitude orbits. Spacecraft can remain syn- chronous with the rotation of the earth only by orbiting at extremely high altitudes. Since the Shuttle Or- biter can't deploy or retrieve space- THE NEW OMR 500 SEES THE An Optical Version of our MR 500 Makes it Even Easier to Enter Data into Your M icrocomputer Now you can read punched holes, preprinted data, or pencil marks on standard OMR cards. All with the Incredibly compact OMR 500 op- tical card reader. Using state-of-the-art fiber optics to "read" each card, a single long- lasting bulb does the job. Reliably and accurately. The OMR 500 is a low-cost alter- nate to keyboard data entry. And at less than 1/2 second per hand- fed card, you won't be sacrificing speed. Compact and lightweight, our new optic reader is a mere 4-lb, 4-Vi Inch cube. Automatic turn-on is standard. The reader is available with in- telligent interfaces to Apple, TRS-80, PET and Atari that simplify user software re- quirements. Also available are RS-232 and SI 00 interfaces. At $1095, including the intelligent interface, the OMR 500 truly adds an affordable new dimension to card reader flexibility. Its uses are virtually unlimited. Small business, the entire educational field, personal computers — wherever data entry is required. And remember, we still offer the industry's largest selection of card readers. So whatever your needs, we've got the right card reader for you. Write or phone for complete details. Better yet, put In your order today. kCHATSWORTH DATA 20710 Lassen Street Chatsworth, California 91311 Phone: (213) 341-9200 craft so far from earth, synchronous- altitude spacecraft must be built to function without service for the dura- tion of their missions. A spacecraft at synchronous altitude appears to remain stationary above one point on the earth's equator. Consequently, a ground sta- tion can stay in continuous com- munication with such a spacecraft. In this respect, spacecraft at syn- chronous altitude are easier to manage from the ground. Satellites orbiting the earth at lower altitudes appear to "rise" and "set" over the ground station. A typical orbit takes about 90 minutes, and the spacecraft is in view of a given tracking station for only 10 minutes of the 90. The ground station must pack a great deal of communica- tion into the 10 minutes of contact. During those 10 minutes, the ground station has to send up enough com- mands for the next 80 minutes of op- erations, check the state of all on- board systems, take any necessary corrective action, and dump recorded data from the satellite to the ground over a high-speed channel. During the 80 minutes when the satellite is out of touch with the ground, the on-board computer must sequence and monitor spacecraft op- erations and components and store messages about the status of monitored equipment. In case of problems, the on-board computer must take first-order corrective ac- tion. Even with the advent in the early 1980s of NASA's tracking sta- tion in the sky — the synchronous- altitude Tracking and Data Relay Satellite System (TDRSS)— full coverage of satellites in near-earth orbits will not be assured because so many satellites will share use of TDRSS. Space-Rating Microprocessors Microprocessors, memories, and interface devices aboard spacecraft must operate in a vacuum over a wide temperature range. The vacuum re- stricts cooling to radiation and con- duction; since no atmosphere is pres- ent, convection is impossible. Besides the limitations on cooling, equipment 116 September 1981 © BYTE Publications Inc Circle 137 on inquiry card. TOTTIPUTER WAREHOUSE CALL TOLL FREE 1-800~528-1054 ATARI Special 32K 800 System 800 W/32K, recorder, star raiders, joysticks. Above w/48K, . . S930 $990 800 (32K) 810 Disk Drive. 825 Printer 850 Interface. . 410 Recorder. . S744 S440 S575 S155 .570 830 Modem S140 16K Memory S75 32K Memory S150 DISK DRIVES Lobo Apple 1st Drive. . . . Apple 2nd Drive. . . MODEMS Novation CAT D-CAT Apple Cat II Auto Cat S490 S410 $155 S155 Call Call PRINTERS C. 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DISKETTS Scotch 5%'0. 10. 16 Sector (Qty 100) 8" 0.32 Sector (Qty 100) MONITORS Panasonic 9" B&W Sanyo 9" B&W 12" Green Call Call Call $250 $260 $150 $150 $240 CALIFORNIA COMPUTER SYSTEMS 64K Dynamic Memory. . $500 1 6K Static Memory $255 Floppy Disk Cont $285 Serial Asynch Board. . . $110 Prices & availability subject to change without notice Personal checks will delay shipping two weeks COmPUTER 2222 E. Indian School Rd. • Phoenix, Arizona 85016 Order Line: 1-800-528-1054 lORf l-|OLl££ ° ther lnformation: 602-954-6109 ■~"^^^^~ ^^ Store Hours: Tues.-Fri. 10-5 MST Saturday 10-3 MST ^2 ^Si Prices reflect 3% cash discount. Product shipped in factory cartons with manufacturers warranty. Add 2%, a minimum of $5, for shipping and handling. must be able to withstand a wide tem- perature variation while dormant. The dormant period includes launch and recovery, during which there is no assurance that the spacecraft can maintain adequate thermal control. Periodic and random vibration and mechanical shock may also damage electronic equipment during the launch phase. A common failure is breakage of a bonded lead wire where it is attached to the die of an inte- grated circuit. High inertial gravity (g) loads can cause such breakage. Space components are usually tested in steady-state acceleration in excess of 30 gs. Instantaneous accelerations, such as those undergone by a chip that is dropped onto a solid floor from a height of approximately a meter, can exceed hundreds of gs. Components of space-borne sys- tems must neither generate electro- magnetic disturbances nor be vulner- able to them. The proximity of other electronic devices and of moderate- power transmitters of radio-fre- quency energy requires resistance to electromagnetic disturbances. The abundance of radiation and high-energy particles pose another threat to semiconductor devices in space. Although there is a self-healing effect if semiconductors are turned off for a while, periodic failures are unac- ceptable in mission-critical functions. Table 1 shows the radiation "hard- ness" of several microprocessors. In general, radiation damage is cumula- tive. Microprocessors of commercial grade fail at several thousand rads total dosage. Although it is possible to attempt shielding chips with aluminum paneling, results are not encouraging. Often, when one high- energy particle strikes the aluminum, more than one high-energy particle comes out the other side. P-type metal-oxide semiconductors (PMOS) are generally less susceptible to radiation damage than are the newer and faster N-type metal-oxide semiconductor (NMOS) devices. Radiation-hardened versions of stan- dard device-families are available, particularly complementary metal- oxide semiconductor (CMOS) de- vices, which are faster than PMOS but slower than NMOS. This is but one instance of space-borne tech- nology lagging behind current com- mercial technology. Perhaps the most serious hurdle that microprocessors must face before becoming main on-board computers is one of sheer computational power. Many of the calculations required of these machines need a word length greater than 16 bits. Until the ap- pearance of 32-bit microprocessors, Power of Suitable Projected Basic Pro- Tech- Support Hardness, cessor, in Device Type nology Circuits in Rads Milliwatts (mW) RCA 1802* Monolithic CMOS Memories, Some I/O 10 5 30 TI-SBP9900 Monolithic l 2 L Memories Only 10' 500 Intersil 6100 Monolithic CMOS Memories, Some I/O 10 5 50 Intel 8080A Monolithic NMOS Memory, Some I/O 10 3 1700 AMD 2900* Bit Slice LS-TTL Memory, All I/O 10 7 10,000 (16 bit) Intel 3000* Bit Slice S-TTL Memory, All I/O 10' 15,000 (16 bit) NMI 6700 Bit Slice LS-TTL Memory, Some I/O 10 7 15,000 (16 bit) * Multiple sources available. Table 1: Comparison of microprocessors for space applications. Included are each processor's radiation "hardness' and its average power consumption. less highly integrated devices will re- tain their monopoly as main on- board computers. On-board Computer Tasks Designers of spacecraft have been relying more and more on on-board computers and associated data sys- tems to give the spacecraft flexibility and autonomy. Tasks assigned to the on-board computer include: • Attitude determination. Orienting the spacecraft in space is a vital and complex function. The spacecraft data system must give the computer data from sun- and star-trackers, earth sensors, and gyros. The atti- tude-determination algorithm calcu- lates how the spacecraft should be aligned with respect to inertial axes. The attitude-control algorithm then issues commands that enable magnet- ic thrusters, jet torquers, or reaction wheels to point the spacecraft (ie: align the axes) to a desired point on earth or to a star. Attitude determina- tion and control, sometimes including orbit-adjust software, typically re- quire 4 to 12 K bytes of memory. • Command Storage. The on-board computer can store sequences of com- mands that are "time-tagged" for later execution. Storage may also include predefined blocks of frequently ex- ecuted command sequences (macros). • Executive. A real-time, multitask- ing, interrupt-driven executive is used to sequence all tasks and to handle input/output operations. • Housekeeping. This includes moni- toring and controlling thermal and electrical power. These tasks may re- quire continual monitoring and limit- checking of sensors in the spacecraft. Spacecraft housekeeping may also in- clude continuous measurement of the batteries' charge. • Telemetry Format Control. The on- board computer may control the sampling and format of the on-board telemetry points. This makes re- configuration possible in response to degradation and failures. 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Etobicoke, Ontario, Canada, Tel: (4161 621-0538 • S.A.Micro Service, Paris, France, Tel: 205 38 71 • Servonic. Munich, West Germany, Tel: 089483253 «GBK, The Netherlands, Tel: 20-733376 • Terrace Computer Sues.. LTD, Terrace, BC,Tel:(604) 635-7606 • DOMESTIC - CEB3, San Jose, CA, Tel: (408)267-3547 • Donald Coffman, Cupertino, CA, Tel: (408) 253-2327 • ERS, Brea, CA, Tel: (714) 524-2470 • Innovative Interfaces, Berkeley, CA, Tel: (415) 524-8416 • ICE Services, Gaithersburg, Maryland, Tel: (301) 869-2896* Khalsa Consultants, Cambridge, MA, Tel: (6171 864-3638 « Link Systems, Santa Monica, CA, Tel: (213)453-1851 • EDS, Frazer, PA, Tel: 1215) 296-7300 •Quali-Type, Inc., Livermore, CA, Tel: (415) 447-6121«SPI, San Diego, CA Tel: 1714) 268-4346 • Khalsa International, Herndon, VA, Tel: (703) 437-0404 • UCSD PASCAL is a trademark of Regents of U. of C CP/M isa trademark of Digital Research, Inc. MuDOS is a trademark of MuSYS Corp. IBS is a trademark of IBS, Inc. 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S.P.) 9-1/2x11 18 lb white 29.00 14-7/8x11 18 lb white 39.00 We stock a complete line of computer covers, printer ribbons, print wheels & NEC thimbles. Call us for your needs. Circle 14 on Inquiry card. We built a reputation on our prices and your satisfaction. We guarantee everything we sell lor 30 days. II anything is wrong, just return the item and we'll make it right. And, ol course, we'll pay the shipping charges. We accept Visa and Master Card on all orders. COD orders accepted up to $300.00. We also accept school purchase orders. Please add $2.00 for standard UPS shipping and handling on orders under 50 pounds, delivered in the continental U.S. Call us lor shipping charges on items that weigh more than 50 pounds. Foreign, FPO and AP0 orders please add 15% for shipping. California residents add 6% sales tax. The prices quoted are only valid for stock on hand and all prices are subject to change without notice. (213) 883-8594 31245 LA BAYA DRIVE, WESTLAKE VILLAGE, CALIFORNIA 91362 Photo 3: ATS-6 Communications Satellite. Traveling in synchronous orbit, the ATS-6 uses two on-board computers for attitude control. fined telemetry format is changed in order to circumvent a hardware prob- lem, the input on the ground-based telemetry processor must, of course, be changed, too. • Instrument Sequencing and Con- trol. The on-board computer can monitor and control instruments directly or can support the in- struments' dedicated microproces- sors. In addition, the on-board com- puter can manage storage of data. Data is recorded during the "back or- bit," when the spacecraft is out of touch with the ground station. When the spacecraft reestablishes contact, data is dumped to the ground over a high-speed data link. Some Essential Capabilities On-board computers must con- stantly perform complex mathemat- ical computations such as coordinate transforms. Floating-point capability enables on-board computers to per- form these computations efficiently. The alternative to building in float- ing-point capability has been to use scaled fixed-point operations. In test- ing, operation, and maintenance, however, the scaled fixed-point ap- proach has led to problems with over- flows, notably aboard Applications- Technology Satellite-6, the Interna- tional Ultra-violet Explorer, and the Solar Maximum Mission. These expe- riences have led to the choice of in- tegral floating-point capability in the on-board computers' processors. Designers may implement floating- point capability in several ways. The most attractive is to have floating- point capability as part of the machine architecture. The architec- ture of several on-board computer systems in the 1980s will implement floating-point capability. If a pro- cessor can't perform floating-point operations, the designer can add the capability by introducing a slave pro- cessor. The slave processor may rely on calculator or computer tech- nology, or it may be a co-processor, sharing the main processor's address, data, and control space. Designers sometimes add firmware containing math-library functions 122 September 1981 © BYTE Publications Inc Circle 1 on Inquiry card. Working hard to be soft. We at 47th Street Photo work very hard to be soft on your pocketbook. We bring you the lowest possible prices on some of the best selling hardware and software available. THE COMPUTER HEADQUARTERS ■ Ill I ■■-«MI1M»»M»«— — [For the best APPLE deal from the big Apple go to the core Wippkz \BUSINESSMAN'S, SPECIAL I Now! Write a letter and print immediately! • Apple II w/48K. • Epson Interface. • Disc w/cont. • Epson Cable. • Sanyo 9" Monitor. • Apple Writer. • Epson MX-80. 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The co-processor and firmware approaches are interim measures to be considered only so long as tech- nological restrictions prevent includ- Processor Approach Used (see table 3) Format Time Needed for Operation in Microseconds (/ts) Add/Subtract Multiply Divide NSSC-1/SP-C32 LSI-11 ATAC-16MS AM9511 3 571 09 3 1b 2 2 1b 1a 24/8 1 24/8 2 24/8 24/8 8-decimal- dlglt- mantissa, 2-digit- decimal 16.5 42.1 to 66.2 5.75 13.5 to 92 22,000 to 66,000 11.5 74 to 121 16 36.5 to 42 32,000 to 227,000 27.0 151 to 232 28.5 38.5 to 46 78,000 to 223,000 8087 4 1c exponent 32 bits; 10 decima digits 18 18 27 1 24-bit mantissa/8-bit exponent 2 Essentially 25-bit mantissa 3 Slave processor only 4 Co-processor with 8086/8088 Table 2: Comparison of arithmetic operations in floating-point hardware. ing these features in the main pro- cessor. Floating-point capability (in the 24-bit-mantissa/8-bit-exponent for- mat) requires at least a 16-bit and pre- ferably a 32-bit word size. Several on- board computer systems in the 1980s will have floating-point capability, and at least one of these will have in- tegral math-library functions. Table 2 compares the floating- point capabilities of several kinds of hardware used in on-board com- puters. Table 3 shows the advantages and disadvantages of different ways of implementing floating-point capa- bility. Table 4 shows execution times of math-library functions in different processors. Higher-Order Language The complexity of the mathematics to be performed aboard a spacecraft gives considerable appeal to the use of a higher-order language in devel- oping flight code. The computer, of course, is indifferent to the program- ming language or method used. 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BYTE September 1981 125 Number Type of (see table 2) Approach Advantages Disadvantages 1a 1b Add-on arithmetic processor Add-on microprocessor Built-in math functions Fast — may proceed in parallel with main micro- Slow Interfacing; no-math library 1c 2 Co-processor Functions built into main microprocessor processor Faster; math-library available Very fast Architecture and inter- facing problems Usually no math- library; math functions must be written in software Table 3 . Comparison of different approaches to floating-point capability. Implementation Time for Fixed-Point Calculations (a) Accuracy (in bits) 16 18 16 in Microsecond s (/*s) Processor Used 9900, with software NSSC-1, with software LSI-11, with software SIN/COS 109 163 176 ATAN/ASIN 236 417 544 SQRT 117 190 184 (b) nt hardware Implementation Time for Floating-Point Calculations in Microseconds (/ts) Processor Used LSI-11 with floating-poi NSSC-1/SP-C32 ATAC-16MS SIN/COS 784 265.2 121.2 ATAN/ASIN 1303 311 235 SQRT 767 223 123.6 (c) Processor Used Format Used Implementation Time for Calculation by Inherent Math-Library Functions in Microseconds 0*s) AM9511' 59109* 8037 Floating-Point Decimal Co-processor ATAN/ASIN 1384 620,500 N/A SQRT 206.5 186,000 36 SIN/COS 1084.25 760,500 N/A * Average of minimum and worst case times Table 4: Implementation times of several math functions in different processors. The functions considered are sine, cosine, arctangent, arcsine, and square root. Table 4a shows the times for fixed-point implementations. Table 4b shows the times for floating-point implementations. Table 4c shows miscellaneous pro- cessor/format combinations. guages increase programmers' effi- ciency. Many programmers now think that they can work more effi- ciently in higher-order languages than in assembly language. But will the use of higher-order lan- guages make testing and maintaining software more difficult? It remains unclear, during operation of a space- craft, whether code produced in as- sembly language is easier to debug and change than code produced by a higher-order-language compiler. But the experience of producing the flight code for the Space Shuttle suggests that language derived from a higher- order language is no more difficult to debug and may even be easier. Among the higher-order languages that are candidates for use with on- board computers are Jovial, HAL/S, and Ada/Pascal. Each has advan- tages and disadvantages. (Space Pro- gramming Language [SPL] was devel- oped by RCA for in-house use and never gained wide acceptance.) In the absence of an effort to develop a com- piler, however, designers will have to use whatever language is supplied by the manufacturer of the hardware. Pascal-like languages impose struc- tured techniques on programmers. Some programmers have faulted Pascal because each program in that language is an entity, lacking external references. But, in creating software for flight-loads, this feature of Pascal should be an advantage because flight-load software must function as an entity. Moreover, Pascal has gained wide acceptance among pro- grammers. And the Department of Defense has adopted Ada, a Pascal- AMS ADVANCED MICRO SYSTEMS • 26188 ADAMOR ROAD • CALABASAS, CA 91302 MORROW DESIGNS products at low low pricesi Tel.: (213) 880-4670 OFFER EXPIRES Oct. 31, 1981 "HARD DISK SUBSYSTEMS M-26 DISCUS M26 $3397.00 M-20 DISCUS M20 $3553.00 M-10 DISCUS M10 $2760.00 ADDITIONAL HARD DISK FLOPPY DISK SUBSYSTEMS TWO DRIVE SUBSYSTEMS A-26 DISCUS M26 A-20 DISCUS M20 A-10 DISCUS M10 $3037 00 $3193 00 $2400 00 F-1118 DISCUS I F-1218 DISCUS 2D F-2218 DISCUS 2 + $ 816.00 $ 888.00 $1105.00 F-1128 DISCUS I F-1228 DISCUS 2D F-2228 DISCUS 2 + 2 $1389 00 S 1450.00 $1896.00 DISK CONTROLLERS (A & T) DJ-M26 M26 HARD DISK $720.00 DJ-M20 M20 HARD DISK S720.00 DJ-M10 M10 HARD DISK $720.00 DJ-2208 DOUBLE DENSITY FLOPPY $349.00 DJ-1 108 SINGLE DENSITY FLOPPY $219.00 STATIC MEMORY (A & T) 16K SUPERAM 16K MEMORY MASTER 24K MEMORY MASTER 32K SUPERAM 65K STATIC RAM $248.00 $284.00 $378.00 $450.00 $870.00 'DECISION I BASIC UNIT $1342.00 NOTE: I/O CONTROLLERS (A & T) I.E.E.E. S-100 BUS (A&T) SB-241 1 SWITCHBOARD I/O SB-241 1 -4K 4K RAM OPTION MB-3200 MULT I/O BOARD $219.00 $ 60.00 $309 00 WB-0800 8 SLOT MOTHER BRD WB-1200 12 SLOT MOTHER BRD. WB-2000 20 SLOT MOTHER BRD $109 00 $129 00 $173.00 1 . The disk subsystems include Digital Research CP/M 2,2 and Microsoft Basic V5.2 2. If you own a MITS controller and disc drive, we have the interface to run them with our new subsystems, and a reformatter for your Pertec drives and software to translate your Mits files to your new operating system. All shipments FOB Calabasas — 90 days warranty on all products Prices, Terms, Specifications subject to change without notice. 126 September 1981 © BYTE Publications Inc Circle 9 on inquiry card. 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 □ With the fast and powerful PL/I-80™ Programming System □ ISV Seminars covering high level applications programming IS V 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 If-TI'rSAm-fti is the worl< — the CP/M® customer base. So why do it alone? Write Digital Research. We'll send you our free brochure detailing the ISV Support Plan. jl DOTAL RESEARCH" P.O. Box 579 Pacific Grove, CA 93950 (408) 649-3896 TWX 910 360 5001 Circle 117 on inquiry card. BYTE September 1981 127 like language. HAL/S was created specifically for generating flight software, but is not designed for use with a small pro- cessor. As with all higher-order lan- guages, HAL/S will only be as good as its compiler implementation, which translates programs into ma- chine language. The choice of which higher-order language is used may not be critical. It would probably not be cost-effec- tive to develop a compiler specifically for use in the space program because all the recommended on-board ma- chines for the 1980s include one higher-order-language compiler. Note, however, that all these com- pilers must be cross-compilers because the flight processor can't sup- port a compiler of its own. Supporting Software The tools that programmers use to develop and maintain software for on-board computers include cross-as- semblers, loading and dumping facilities, and simulation facilities. • Cross- Assemblers. Despite the ex- istence of several higher-order lan- guages for spacecraft computers, pro- grammers still work mostly in assem- bly language. Since the on-board computer doesn't host its own sup- port software, the cross-compilers, cross-assemblers, editors, and linkers reside in a small- or medium-scale computer system used for support. Programmers work on this support system, using its convenient facilities such as video display, disk and tape drives, and a printer. The code pro- duced is then "downline loaded" to the flight computer or test facility or transferred via tape image. • Loading and Dumping. The soft- ware load-image for the on-board computer must be mapped into space- craft commands through the com- mand link, as shown in figure 1. The ground control center usually does this mapping, and then uplinks the commands to the spacecraft via a tracking, telemetry, and command station. On the spacecraft, the com- mand receiver routes the commands to the computer, where they are inter- preted. The NSSC-1 on-board com- puter, discussed at length later, can be hardware-loaded (without the in- tervention of on-board software) or can be loaded by use of the executive program. The latter technique, how- ever, is used only to update non- critical parts of the code. The memory of the on-board com- puter can be dumped on command. The on-board computer puts its mem- ory words into the spacecraft telemetry stream. A ground station receives these memory words and then relays them to the control center. After software decodes and formats the dump image, the support computer prints a copy. Simulation Facilities NASA often uses simulation to test the hardware and software of on- board computers. A program hosted in a mini-computer or in a still larger machine is made to appear to the on- board computer as the rest of the spacecraft. A large and complex real- time simulation generates sensor data and accepts torquer commands, exer- cising the on-board computer in many different hypothetical situa- tions. In addition to serving as the major debugging and analysis tools for flight software, simulations are used to train control-center crews. Debugging Software in Orbit After thousands of man-years of testing, an on-board computer is launched and assumes full control of spacecraft operations. All too often, the on-board computer crashes because of an obscure and improb- able set of conditions that no one even dreamed of simulating. How does an analyst debug and patch software in a computer that is in orbit? If the control software de- sign is good, an analyst can sit down at the console, dump memory, and patch code without having to worry about the vast amount of hardware and software between him or her and the on-board computer. The analyst of the on-board computer is in fact communicating with the control- center computer, which is in contact with the on-board computer through CHANGES EDITOR CROSS ASSEMBLER LINKER SUPPORT COMPUTER LOAD IMAGE FILE TRANSLATE TO SPACECRAFT COMMANDS UPLINK SPACECRAFT ON-BOARD COMPUTER SPACECRAFT TRACKING, TELEMETRY. AND COMMAND STATION CONTROL CENTER Figure 1: Diagram of the process of changing software for the on-board computer. After software is revised using the support com- puter in the ground control center, the new code is translated to spacecraft commands, linked, sent to the spacecraft through a track- ing, telemetry, and command station, and placed into the spacecraft's on-board computer. 128 September 1981 © BYTE Publications Inc Systems 1 a total business system. JOB COSTING MENU 1. TRANSACTION ENTRY/DATE 2. JOB/TASK TABLE MAINTENANCE i 3. JOB COST FILE MAINTENANCE 4. JOB COST REPORTING 5. EMPLOYEE TABLE MAINTENANCE 6. RETURN TO MASTER MENU SELECT |1-6|? mjFr SYSTEMS II EX MASTER MENU 1. INVENTORY 7.CHART0FACCTS. 2. PAYABLES 8. VENDOR MAINT. 3. RECEIVABLES 9. CUST. MAINT. 4. PAYROLL 10.CHANGEOATE 5. LEDGER 11. SYS/BACKUP 6. JOURNAL 12.STOP PROCSSG. 13. OPTIONAL PROCSSG. L. SELECT 11-13]? DATABASE MENU 1. FILE MAINTENANCE 2. REPORTS/REPORT MAINT. 3. UTILITIES 4. RETURN TO SYSTEM MENU SELECT [1-4]? ACCOUNTS PAYABLES MENU 1. FILE MAINTENANCE 2. PAYMENT SELECTION 3. PRINT CHECKS AND REGISTER 4. MONTH END 5. RETURN TO MASTER MENU SELECT |1-5|? RECEIVABLES SYSTEM MENU 1. FILE MAINTENANCE 2. RECEIPT OF PAYMENTS 3. GENERATE BILLING 4. MONTH END 5. PAST DUE REPORT 6. APPLY MONTHLY INTEREST 7. RETURN TO MASTER MENU SELECT (17)? LEDGER SYSTEM MENU 1. FILE MAINTENANCE 2. BAL SHEET/INCOME STATEMENT 3. YEAR END PROCESS 4. RETURN TO MASTER MENU SELECT (14)? INVENTORY SYSTEM MENU TIME DATE 1. FILE MAINTENANCE 2. POINT OF SALES 3. REORDER REPORT 4. RETURN TO MASTER MENU I SELECT (1-4)? SYSTEMS II EX — EX for EXTENDED PERFORMANCE. Westware brings you the most completely integrated and simplest to use business software for your Apple Computer. The SYSTEMS II EX is complete with an integrated Database. Yes! The DBII Database can move your system's files into Database format for customized reports or labels. Although the SYSTEMS II EX is a fully integrated system, you may purchase individual modules and later add additional modules, such as Job Costing for contractors. The power of our system is in the KSAM Firmware card that plugs into the Apple. This card permits high speed searches and eliminates running sort routines to get your files in order. SYSTEMS II is available on 5%" drives, and also on the Corvus hard disk. A Corvus based system will give you the power and capacity that challenges larger computers. STATE PAYROLL MENU 1. MISC/TAX TABLE MAINT. 2. TRANSACTION FILE 3. MISC. PAY/DEDUCTION FILE 4. EMPLOYEE MASTER FILE 5. CALCULATE/PRINT CHECKS 6. PRINT W2s 7. RETURN TO MASTER MENU SELECT 11-7)? COMING SOON — Cash flow analysis with graphics, Database II with graphics, and Bill of Materials for small manufacturers. CURRENT OPTIONS AVAILABLE — Job Costing, Cycle Invoicing, Order entry, and Layaway. All Checks, statements and invoices use NEBS forms. Dealer and OEM inquiries invited. Apple is a trademark of Apple Computers. Systems H 2455 S.W. 4th Ave. Suite 2 Ontario, OR 97914 (503) 881-1477 See us at the Midwest Computer Show Circle 383 on Inquiry card. Yes. please send me your Systems II Demo Package. □ Yes, I would like to sample your software. Please send me the Systems II Demo Package. My check for $25 is enclosed. Name 2455 S.W. 4th Ave. Suite 2 Ontario, OR 97914 (503) 881-1477 Title Company Name. Address City State . Zip. NO FRILLS! NO GIMMICKS! 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S . residents add Sales Tax Shipping F.O.B. N.Y, Phone Orders Call (212) 895-5577 a Tracking, Telemetry and Command Station. During a crisis, however, the analyst doesn't want to think about these details. Fixing Failures in Orbit Once diagnosed, software failures can be corrected by partially or com- pletely reloading memory. Complete reloads are possible but time-consum- ing. Remember that the ground con- trol center often has only 10 minutes in every 90 for communication. Hardware failures in orbit are more difficult to diagnose and fix. Al- though the Shuttle Orbiter will have a tape drive for storing software, most on-board computers lack mass-mem- ory units. Using disk drives in orbit, except in the largest vehicles, leads to problems because of the need to com- pensate for the drives' rotational angular momentum. Perhaps two identical disk drives revolving in op- posite directions would compensate for each other. But the main problem in fixing hardware is that only one technique is possible: turning off the equipment for a while. This treatment fixes some failures caused by radia- tion. Analysts in the control center can sometimes work around a hardware failure. When the computer on the Orbiting Astronomical Observatory failed, for example, analysts deter- mined that a bit in the adder had be- come unreliable. They rewrote the software to avoid using that bit. It is possible to work around failed mem- ory in a similar fashion. In the era of the space shuttle, it will be possible to replace modules containing a failed computer or even to bring an entire spacecraft back to earth for repairs. Most current space- craft designs incorporate hard-wired functions, independent of on-board computers, that will enable the Space Shuttle to approach and retrieve a spacecraft that has a malfunctioning computer. Early Systems Spacecraft computers started out as a natural outgrowth of missile-guid- ance computers — simple sequencers. In the late 1950s and early 1960s, missile-guidance computers were ground-based and had tube or tran- sistor technology. One of these early devices is on display at the Smithso- nian Museum of History and Tech- nology in Washington, DC. With the advance of technology, designers were able to place missile- guidance functions in an on-board computer. The main work of the mis- sile-guidance computer remained the sequencing of operations. The mis- sile-guidance computer had to work for only about 30 minutes. Com- puters aboard spacecraft, of course, have to perform a greater variety of functions and to go on working much longer. The first NASA spacecraft that in- corporated a general-purpose com- puter was the Orbiting Astronomical Observatory, launched in 1972. Called the On-board Processor (OBP), this first on-board computer was built by NASA and was the precursor and engineering model of the NSSC-1. Although the OBP was included mainly as an experiment, the computer helped prolong the life of the mission until December 1980 despite many on-board equipment degradations, including the failure of a bit in the computer's adder, as described earlier. Current Systems Table 5 shows details of some cur- rent on-board computer systems. Note that most missions include two processors. The AMSAT Phase III, designed and built by amateurs, in- cludes a CMOS processor. Favored storage devices in current systems in- clude core and plated-wire devices. The systems shown in table 5 contain no secondary memory storage. Pre- ferred technology is high-reliability TTL (transistor-transistor logic) or radiation-hardened CMOS. Typical machine cycle times are several microseconds. On-board computers are examples of embedded computer systems — they perform as subsystems and per- form only a specific application. As microprocessor technology evolves toward a chip with a processor in the class of the IBM System 370, micro- processors will increasingly serve as on-board computers. 130 September 1981 © BYTE Publications Inc C #Pascal Efficiency^Portability 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 h LSI-11 /PDP-11 lachines VAX-11 M6800 8080 /Z80 CP/M C: $750 Pascal: $950 * * * LSI-11/ PDP-11: Idris, Unix, RT11, RSX-ll/M, RSTS/E, IAS C: $1350 Pascal: $1550 C: $750 Pascal: $950 * C: $1350 Pascal: $1550 VAX-11 Unix/V32 VMS C: $1350 Pascal: $1550 * C: $750 Pascal: $950 C: $1350 Pascal: $1550 M68000 VERSAdos # * * C: $750 Pascal: $950 Idris is a trademark of Whitesmiths, Ltd. RSX-ll/M, RSTS/E, LSI-11, VAX, are trademarks of Digital Equipment Corporation ■ VERSAdos is a trademark of Motorola Corporation Protect .your software * Special ° rder \\r r1 investment. ♦ 1 y t Wmtesmiths, Ltd RO.Box 1132 Ansonia Station New York, N.Y. 10023 (212)7994200 Distributors: Australia Japan United Kingdom Fawnray Pty Ltd. Advance Industries Real Time Systems Brighton-Le-Sands Tokyo Newcastle upon Tyne 5225574 03-258-0839 0632 733131 BYTE September 1981 131 Type of Computer Mission Number Memory Size Memory Type Processor Cycle Time 1. NSSC-1 M MS (Generic) 1 or 2 8-64 K by 18 bits CORE TTL 1.5/ts 2. AOP Landsat-B/C 1 4 K by 18 bits PWM TTL — 3. NSSC-1 SMM 2 48 K by 18 bits PWM TTL 1.4/is 4. AOP IUE 2 12Kby 18 bits PWM TTL 1.3/ts 5. OBP OAO-C 1 16 K by 18 bits CORE DTL 2.0us 6. DOC ATS-6 2 4Kby 16 bits PWM LPTTL 5.0/iS 7. GCSC Viking Lander 2 18 K by 18 bits PWM LPTTL 5.cys 8. CCS Viking Orbiter 2 8Kby 18 bits PWM — — 9. FDS MJS-77 (Voyager) 2 8K by 16 bits CMOS DMOS 2.48/iS 10. CCS MJS-77 (Voyager) 2 8 K by 18 bits PWM — 1 .37/xS 11. AACS MJS-77 (Voyager) 2 8 K by 18 bits PWM — 1 ,37/jS 12. SCP-234 TIROS-N 2 18 K by 16 bits CMOS CMOS 2.34jtS 13. SCP-234(USAF) Block 5D 2 16Kby 16 bits CMOS CMOS — 14. COSMAC AMSAT Phase 1MB 1 16 K by 8 bits CMOS CMOS Vs 15. NSSC-1* Landsat-D 2 64Kby 18 bits CORE TTL 1.5/iS 16. ATAC-16ms* Galileo (AACS) 2 32 K by 16 bits CMOS (hardened) LSI bit slice 250 ns 17. CDC 469 HEAO 2 16 K by 16 bits Plated Wire PMOS/LSI Table 5: Characteristics of some currer t on-board computer systems. * Not yet launched. Table 6 shows processors that are available for space missions in the 1980s. Among the features summa- rized in table 6 are the higher-order languages that are offered for use with these processors. The table also gives the times required by each pro- cessor for addition, multiplication, and division in both fixed- and float- ing-point operations. Spacecraft Computer-1 Current plans call for use of the NASA Standard Spacecraft Com- puter-1 (NSSC-1) for flights using the Multimission Modular Spacecraft. Computer Category Manufacturer Heritage to Previous Computers Space Applications NSSC-1 IBM SMM, IUE MMS Fixed-Point Word Size, Bits* 18/35 Floating-Point Word Size, Bits* 35/18 Size, Cubic Inches 570 Weight, Pounds 17 Power, Watts 45 High-Order Language JOVIAL SPL HAL/S • Ada/Pascal Fixed-Point Execution Time, /ts Addition/Subtraction 5 Multiplication 38 Division 75 Floating-Point Execution Time, us Addition/Subtraction 393 Multiplication 580 Division 909 NSSC-1 SP-C32 IBM/MM None None 18/35 24/8 N/A N/A N/A NSSC-1 1 IBM None None 32 24/8 1232 28 150 ATAC-16ms M3625 ITEK Delco ECW TITAN I Avionics F-16 Galileo IUS 16/32 16/32 24/8 24/8 609 1250 18 54 31 190 SCP-234 RCA None TIROS-N 16/32 N/A 655 7.9 10 5 N/A 0.25 0.8 4.68 38 8.5 5.0 2.8 59 75 17.5 10.2 5.8 101 16.5 N/A 5.8 2.6 N/A 11.5 38 17.5 4.6 N/A 27 56 29.2 9.8 N/A Cost in thousands of dollars 205 355 N/A 115 1600 N/A * Bits in Mantissa/Bits in Exponent N/A = Not Available Table 6: Characteristics of processors available for space missions in the 1980s. 132 September 1981 © BYTE Publications Inc CMOS - Complementary Metal-Oxide Semiconductor DOC - Digital Operations Controller DTL • Diode-Transistor Logic FDS - Flight Data Subsystem LPTTL - Low-Power Transistor-Transistor Logic OBP - On-board Processor PWM - Plated-Wire Memory NSSC-1 - NASA Standard Spacecraft Computer TTL - Transistor-Transistor Logic MMS - Multimission Modular Spacecraft AACS - Attitude and Articulation Control Subsystem SMM - Solar Maximum Mission AOP - Advanced On-board Processor = NSSC-1 IUE - International Ultraviolet Explorer CCS - Computer Command Subsystem OAO - Orbiting Astronomical Observatory uS - 10~ 6 seconds ATS-6 - Applications Technology Satellite ns - 10"' seconds Flying in various configurations, this modular satellite will perform many NASA missions. The NSSC-1 occupies 122 cubic inches, weighs 3 pounds and requires a 5-watt power supply. A fixed-point, two's-complement computer with a word length of 18 bits, the NSSC-1 has 55 instructions and performs an add operation in 5 (is, a hardware multiply operation in 38 /is, and a divide operation in 75 ps. All these items are based on use of a 1.6 MHz clock. The NSSC-1 has one index reg- ister, one double-length accumulator, MECA DF-224 FTSC 469 GPC CMOS/SOS 4516E Teledyne Autonetics Raytheon CDC IBM TRACOR Litton DELTA, None None HEAO N/A AN/UYK-20 N/A CENTAUR None Space Telescope None None Shuttle None None 16/24/32 24 32 16/32 36 1632 16/32 24/8 NO N/A NO YES 24/8 YES 1091 N/A N/A N/A N/A N/A N/A 49 102 50 10 59 N/A 18 74 • 85 35 20 350 5 34 1.6 1.6 5.4 4 • 1.9 0.75 2.5 3.94 8 11 10.4 5.7 4 21 N/A N/A N/A N/A N/A 8 N/A 6.6 N/A N/A N/A N/A 3.75 N/A 11.12 N/A N/A N/A N/A 10 N/A N/A N/A N/A N/A N/A 15 N/A N/A 2250 1000 650 500 N/A 115 September 1981 © BYTE Publications Inc 133 v r HIGH-RATE EXTERNALLY GENERATED DATA SOURCES S-BAND TRANSPONDER COMMAND DETECTOR PRE-MOD PROCESSOR TAPE RECORDERS L. STACC CENTRAL UNIT COMMAND DECODER FORMAT GENERATOR BUS CONTROL & INTERFACE SPACECRAFT CLOCK STACC INTERFACE UNIT STINT 7~> S~> '1 ON-BOARD COMPUTER (CBC) REMOTE INTERFACE UNIT NO.l MULTIPLEX DATA BUS RIU NO. 2 RIU NO. n SPACECRAFT COMPONENTS Figure 2: Simplified block diagram of the Command and Data Handling module of the Multimission Modular Spacecraft. and features indirect addressing. It has 16 interrupt levels and handles as many as 16 direct-memory-access de- vices over a single 100-word-per-sec- ond channel. The addressing range of the NSSC-1 is 64 K words of memory. The NSSC-1 contains memory built of 8 K-word blocks and features paged addressing, by means of which all 4096 words in a given page are ac- cessed directly. Normally, data and code reside in different pages. Dynamic write-protect is applicable to 128-word blocks of memory. Memory units on the NSSC-1 use power switching to reduce consump- tion of energy when units are not being addressed. Since the NSSC-1 contains no ROM (read-only memory), the com- puter has a direct-load feature that allows loading a "cold" machine through the spacecraft command link. By contrast, the Digital Opera- tions Controller on Applications Technology Satellite-6 did have mem- ory-load and "bootstrap" ROM soft- ware. Of course, if a ROM contains a programming error, it can't be cor- rected while in orbit. Multimission Spacecraft The characteristics of the MMS (Multimission Modular Spacecraft) impose many requirements on the NSSC-1. The MMS consists of three building-block modules and a sup- porting structure. The modules — Power, Attitude-Control, and Com- mand and Data Handling equip- ment — provide ready-made space- craft components. Combining an MMS with an instrument module makes a spacecraft that the Space Shuttle can launch and retrieve. The first MMS spacecraft to be launched was the Solar Maximum Mission in February 1980. The next is Landsat-D scheduled for July 1982. Aboard the MMS, the NSSC-1 re- sides in the Command and Data Han- dling module as part of the spacecraft data bus. This module contains telemetry transmitters and command receivers for spacecraft operation. The Command and Data Handling module can include as many as three standard 10 B -bit or two standard lO'-bit recorders for temporary stor- age of data for the spacecraft or the instruments on board. The Command and Data Handling module also con- tains the basic timing-reference signal for the spacecraft, accurate to 1 in 10 6 parts and stable to 2 in 10 8 parts per day. Instruments themselves may in- clude more accurate clocks. The most important component of the MMS data system is the multiplex data bus. The bus is a set of redun- dant party lines and has both super- visory and reply lines. The multiplex data bus links all components of the spacecraft. The only data that doesn't flow through the multiplex data bus is data transmitted at rates greater than a megabit per second. Linking each spacecraft component to the data bus is a special interface called a Remote Interface Unit. Since the bus is configured as a party line, each Remote Interface Unit has a unique address ranging from 1 to 63. 134 September 1981 © BYTE Publications Inc Geta *20 rebate on the TI-59 Programmable. Even without the $20 rebate, the TI-59 is special — it's our most powerful programmable, and we've never offered it at a lower price. The TI-59 gives you up to 960 program steps, or up to 100 memories, plus magnetic card read/write capability. You can also slip in one of TI's Solid State Software™ modules and successfully attack complex engineering, business, statistical and scientific problems. And by adding the optional PC-100C printer, you can record your calculations. But if that's not enough, any TI-59 owner can join our Professional Program Exchange for access to over 2500 additional programs. So if you like the idea of having real programmable power, take us up on the rebate offer. Buy a TI-59 now, and fill out the coupon below. The offer ends December 31, 1981. Texas Instruments INCORPORATED NAME. ADDRESS CITY. ©1981 Texas Instruments Incorporated I bought my TI-59 Programmable at (store name): and have attached the dated sales receipt and completed customer infor- mation card (packed in box). My TI-59 Serial No. is (from back of calculator). Please send my $20 rebate check to: . STATE Send to: Texas Instruments TI-59 Rebate Offer, P. O. Box 725 Dept. 59, Lubbock, Texas 79491. NOTE: Proof of purchase must be dated between August 1, 1981 and December 31, 1981. Offer void where prohibited. Offer good only in U.S.A. Rebate applies to purchases of TI-59 Programmable only. Items must be postmarked by January 15, 1982. Allow 30 days for delivery. Limit one per person/addrei 1002 ■ ■ ►***', I ■ - wu i • Over the past seven years we've earned a name for ourselves by making the best magnetic mc^dla in the business. Precision magnetic media — Diskettes, Mini Diskettes, Diagnostic Disk- ettes, Rigid Discs, Disc Packs, and Disc Cartridges -all certified to be 100% error free both on-track and between the tracks. Now we're making it easier for you CO buy the best. Just dial Dysan direct TOLL FREE at 800/538-8150 or 408/988-3472 {iu Cali- fornia) or contact your lo( al Dysan office listed below. Precision magnetic media from Dysan. Our media says it all. M Dysan 5440 Patrick Henry Dri\ Santa Clara, CA 95050 408/988 'Al/ I T i * -/■'•v*/?"-' t Jc ite-^i^" Call your local Dysan office: • Irvine, CA (714)851-9462 • Sunnyvale, CA (408) 730-2145 • Atlanta, GA (404) 952-0919 • Schaumburg. IL (312) 882-8176 • Burlington, MA (617) 273-5955 • St. Louis, MO (314) 434-401 1 • Glendora, NJ (609) 939-4762 • New York, NY (212) 687-7122 • Bellevue. WA (206) 455-4725 Watch for new offices opening soon. For further information, call our Corporate Marketing Department at (800) 538-8150. Circle 130 on inquiry card. £5 o< CO LU >T = s CO _l 25 is So cncD coo +cl * S ". or or -J .3 LU< °< >1- HH 5? 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CALL NEC 12" RGB Hi-Res Color CALL Panasonic 13" Color 449 Sanyo 9" B&W 159 Sanyo 12" B&W 239 Sanyo 12" P31 Green Phospher 279 Sanyo 13" Color w/excellent resolution 419 ORDER TOLL FREE 800-854-6654 WE ACCEPT ALL MAJOR CARDS California and outside Continental U.S. (714) 698-8088 ^_ ^^ _^ j-t.^^,^ 8314 Parkway Drive gQDQSGDQDDQir G®D0Q[p[HO®[?§ mail ordcr ^ Mesa, ca 92041 C/5 m m > o m ON O X 2 > Z o pa m o o G n H (f) > H c z 00 m > > r m 22 o m Circle 93 on inquiry card. BYTE September 1981 139 Circle 220 on Inquiry card. micro S€€D The Powerful Mainframe Database Management System for Professionals Who Use Microcomputers Power: Mlcro-SEED was derived from the CODASYL SEED database system. It has both hierarchial and network struc- tures with power to handle any applica- tion regardless of its data complexities. Compatibility: Fully compatible with SEED for creating microcomputer data- bases tied to a large host computer. Productivity: Faster and easier to develop and maintain applications since data relationships are automatically and consistently maintained. Shared database allows integration of various application programs, each having selective authori- zation to access data. Consistent data naming allows programs to evolve in- dependently of one another. Performance: Since only ticro-SEED gives you full CODASYL access methods (plus additional ones), your database can be tuned for maximum performance. Critical portions of >-SEED are writ- ten in assembly language for fast, effi- cient operation, while the remainder is in standard FORTRAN to permit rapid evolution of . Your data is secure since the database is never damaged in a system failure. Only the last transaction is lost. Proven: Micro-SEED has been in use since 1977 and is continually enhanced. Ease of Use: Documentation consists of a Reference Manual (over 100 pages) and a CP/M Operating Guide. Also, three example databases are illustrated in detail. Concise Data Definition and Data Manipulation Languages permit easy structuring and updating of your database. When Your Application Requires BIG Computer Power at little Computer Prices, Get Micro EED. Requirements are CP/M operating system, FORTRAN or PL/l-80, 48K bytes available to user program, and Zilog Z-80 or Intel 8080/8085 processor. Format is 8 " single- density; others on special order. Single copy license is $1,195. Demonstration Package with Documentation is $75. Documentation only is $40. VISA, MC, and AE accepted. Dealer and OEM inquiries invited. »•■ 4890 Riverbend Road Boulder, CO 80301 Phone (303) 443-2706 fflicro Dedsionwctre SEED trademark of International Data Base Systems (IDBS), Micro-SEED trademark of IDBS and Micro Decisionware CP/M and PL/l-80 trademark of Digital Research. 140 September 1981 © BYTE Publications Inc Each Remote Interface Unit can han- dle 8 serial-magnitude and 64 pulse- type commands. (In a serial-magni- tude command, the whole byte is taken to have one value. In a pulse- type command, each bit is an "on" or "off.") A Remote Interface Unit can also handle 64 telemetry channels. Some spacecraft components have more than one Remote Interface Unit assigned to them. The bus supervisory lines are time- division multiplexed. They carry command messages and addresses for interrogated telemetry. Four basic message types, each 32 bits long, make up a basic 125-microsecond supervisory-bus timing cycle. Data on the reply bus moves in 8-bit packets. The data bus is basically a 1.024-megabits-per-second serial line. The STACC (standard telemetry and command components) central unit is the main interface between the spacecraft data bus and the command receiver/transponders, the telemetry modulators/transmitters, and the on- board computer. The on-board com- puter, however, is not interfaced dir- ectly to the STACC but through the STINT (STACC Interface Unit). Figure 2 shows a simplified view of the Command and Data Handling module. Note that the path for ex- tremely high-rate data bypasses the bus and feeds the telemetry modula- tors directly. Also note that the op- tional tape recorders may be used to buffer telemetry data for later transmission to the ground. Figure 3 is a fuller block diagram of the Command and Data Handling module with all its interfaces. The diagram shows that the Command and Data Handling module contains redundant copies of every compo- nent. There are two processors for the NSSC-1, but only one complement of memory. Only one of the NSSC-l's processors can be powered at a time, and either processor can address all of the memory. So far, as its commands and its contributions to telemetry are con- cerned, the NSSC-1 is just another component of the bus. Most bus traf- fic consists of interrogation ad- dresses, commands going out to com- ponents, and data for telemetry. The STACC unit, under ROM control, re- quests telemetry data in a certain for- mat. The NSSC-1 can modify that format if necessary. When the computer needs certain data faster than it is normally sampled from telemetry, the on- board computer can request and receive the needed data over the bus. Such data is then "interleaved" with telemetry data. One design considera- tion is to prevent the telemetry for- matter and the on-board computer from contending to sample the same device at the same time. The Future and the NSSC-1 The NSSC-1 is a production-model computer that is adequate for today's missions. Because more and more data-processing tasks are being as- signed to the NSSC-1, its adequacy for missions in the 1980s is question- able. NASA is considering several ap- proaches to increase computing power in on-board computers of the 1980s. In an attempt to avoid complete re- design of a basically adequate compo- nent, NASA has investigated several schemes to augment the NSSC-1 within the framework of the current design. These schemes include the ad- dition of floating-point hardware and the off-loading of large computa- tional tasks to dedicated microproces- sors. One study proposes using a micro- processor to collect, format, and pro- cess data from the spacecraft's gyro- scopes. This task is a time-consum- ing, repetitive computational burden that could easily be shifted to a microprocessor. A similar proposal calls for shifting the attitude determination and con- trol algorithm, representing approxi- mately 40 percent of the NSSC-l's computational load, to a dedicated microcomputer. It turns out that the Texas Instruments 9900 microproces- sor would be ideal for this applica- tion. The input/output from most of the spacecraft's devices is serial and has word sizes up to 24 bits, and the 9900 has an inherently serial input/output structure. Microprocessors could also relieve the NSSC-1 of several other modular Circle 269 on inquiry card. > Mix APPLES and ORANGES? . . . And you get GRAPHICS! . THE GRAPPLER I™ Apple Parallel Interface and Cable FROM ORANGE MICRO The Grappler™ Interface is the first universal parallel interface card to provide sophisticated on-board firmware for Apple high resolu- tion dot graphics. No longer does the user need to load clumsy software routines to dump screen graphics — it's all in a chip. Actually, it's our E-PROM, and there are versions to accommodate the Anadex, Epson MX100, MX80 & MX70, IDS Paper Tigers, Centronics 739, and future graphics printers. The Grappler™ ac- cepts 18 simple software commands accessible through the key- board or user program, making it the most intelligent Apple inter- face available. GRAPPLER INTERFACE FEATURES The High-Resolution Graphics commands include: select page 1 or page 2, print inverse graphics, rotate picture 90°, print double size picture, center graphics, and chart recorder mode. The Text commands allow the user to turn off the printer bell (Epson), turn on high bit for block graphics (Epson MX80 and Okidata), set left and right margins, set auto skip-over-perf., variable line length wrap- around with breakpoint on nearest blank, and text screen dump. $ 165.°° Includes Cable Dealer/Distributor Inquiries Invited M9N MX80/MX70 FRICTION FEED FROM ORANGE MICRO HERE AT LAST! A high quality friction feed kit for your EPSON MX80/70. The kit allows the user to convert his Epson printer to a friction feed and pin feed mechanism. It uses a solid rubber platen for perfect tracking. The friction feed will accept single sheets of your letterhead, or multiple copy forms such as invoices with up to 4 part carbon copies. The pin feed replaces the adjustable sprocket mechanism. It allows the use of 9Vz " wide continuous fanfold paper which is an industry standard size. No drilling is required. Initial installation takes about 30 minutes; return to adjustable sprockets in just 10 minutes. All parts are included with easy to follow instructions. CALL TOLL FREE: (800) 854-8275 CA,AK, HI (714) 630-3322 Phone orders WELCOME; sam3l day shipment. Free use of VISA & MASTERCARD. COD's accepted. Manufacturer's warranty Included on all equipment. Prices subject to 75 00 Dealer/Distributor Inquiries Invited RETAIL PRINTER STORES: 3150 E. La Palma, #l, Anaheim, CA. 13604 Ventura Bl., Sherman Oaks, CA. Store Hours: M-F 10-6 Sat. 10-4 VISA rsi Orange micro inc. ©1981 Orange Micro, Inc. 3150 E. La Palma Suite G, Anaheim, CA 92806 tasks. One of these is the calculation- of-orbit position. These calculations rely on frequently updated data from the ground and usually involve evalu- ating long time-series polynomials. Extremely difficult to do without floating-point, calculations of posi- tion usually require at least 32 bits of precision, or a 24-bit mantissa and 8-bit exponent. A recent study pro- jected that the on-board computer would be required to perform 1300 floating-point operations per second; 60 percent of the operations were short, such as addition, and 40 per- cent were long, such as division and multiplication. The NSSC-1 can do only 30 of these computations per second and not in floating-point. (When the Global Positioning System that is described later becomes opera- tional, it will greatly simplify the task of determining position.) Table 7 compares the performance of the NSSC-1 with that of several current microprocessors. Ignoring word size, the NSSC-1 may be thought of as the approximate equal of a PDP-8 class minicomputer. Spacecraft Applications Designers are using microproces- sors more and more as dedicated con- trollers on spacecraft. The current trend is to give each major instrument its own dedicated microprocessor. This is a step toward on-board distri- buted processing. Another concept under study is creating a pool of microcomputers to serve all the spacecraft's instruments in common, providing extensive backup at the cost of greater complexity. A microprocessor inside an instru- ment can monitor and sequence the instrument's operation as well as carry out some first-level reduction of data. Since much of this data reduc- tion is now done on larger computers on the ground, the use of micropro- cessors inside instruments will greatly reduce the amount of data that must be transmitted from the spaceship to ground stations. But designers must also weigh the possibility of losing valuable data due to a malfunction of a microprocessor aboard a spacecraft. The specter of a perfectly functioning instrument de- feated by a failed microprocessor haunts instrument scientists. De- signers must also assure that the sup- port required for the space-borne pro- cessor does not become greater than the computer resources required if the job is done on the ground. Before a scientific instrument can become operational on a spacecraft, scientists must specify the required data-processing algorithm and the format of the output data. Then the processing resources required can be estimated, basically in terms of time and memory. Then a decision can be made as to where the processing can best be done — on the ground or in the spacecraft. One or more Remote Interface Units connect the microprocessor- based instrument processor with the MMS multiplex data bus. Data rates from X-ray instruments typically car- ried on MMS spacecraft usually do not exceed 256 k bps (bits per sec- ond). Gamma-ray instruments usual- ly result in less data by an order of magnitude. Techniques often applied in in- struments' dedicated processors in- clude: spectral analysis by fast Fourier transform algorithms for two dimensions; time-domain analysis, such as burst detection and periodici- ty detection; and the detection of transients for modification of instru- ment operation in real time. Payloads designed for the space shuttle flights of the 1980s draw heavily on microprocessor tech- nology, often using microprocessors in place of discrete logic and hard- wired controllers. In such applica- tions, microprocessors provide an un- precedented level of complexity and flexibility. An example is the Payload Assist Module-Delta Class (PAM-D), a sort of second stage for the shuttle. The PAM-D will boost spacecraft to a final orbit beyond what the Shuttle Orbiter can achieve directly. Several microprocessors aboard the PAM-D will check and cross-check safety fea- tures, sequence operations, and inter- face with the Shuttle's and the pay- load satellite's data systems. Global Positioning System The GPS (Global Positioning Sys- tem) will consist of a network of or- biting spacecraft that provides global coverage. The GPS is designed to yield highly accurate data about the positions of earth satellites. The GPS satellites and ground stations are also known collectively as the NAVSTAR system. The experimental model of the GPS receiver to be carried on Landsat-D uses a dedicated LSI-11 processor to calculate position in orbit. Using data received from orbiting GPS space- craft, the GPS receiver can locate Landsat-D's position within meters on the earth's surface or in orbit. This will enable the satellite to make accu- Number Word Tech- Word Regis- Cycle of Instruc- Add Addressing Temp Processor nology Size ters Time tions Time Multiply Divide Capability Range NSSC-1 TTL 18 3 1.6/is 55 5/iS 38 ^s 75/iS 64 K -10° to + 40°C 8080A NMOS 8 7 1.5/is 91 3/»s — — 64 K -55° to +125°C 9900 NMOS (l 2 L) 16 16 .333^s 64 4.67 /ts 17.33/iS 30/iS 32 K 0° to + 70°C LSI-11 NMOS 16 8 .38/js 74 3ps 70/iS 80/ts 32 K 0° to +50°C 1802 CMOS 8 16 1.24/ts 75 2.5/is 64 K -55° to +125°C ATAC-16ms Schottky 16 16 .250/is 129 .25/js 5.5/iS 11.25 pes 64 K MIL Spec Table 7: Comparison of on-board computers with rr icroprocessors 142 September 1981 © BYTE Publications Inc Circle 200 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. /— * 1_^_ //t~\_.l r~^ j 1 // 1_- — : „ „.. 1 J with resolution to 120 x 144 dots per inch. Interfacing is easy with both E.I. 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, CA 91361 , (805) 496-1990 a subsidiary of Datarnetncs Corporation Electronics Corporation DOTS DO IT BETTER™ rate correlation of its observations with latitude and longitude. The GPS receiver is a "black box" device — that is, all that the user needs to know about it is the format of data that the GPS receiver accepts and produces. But the processor inside the GPS receiver is basically an LSI-11. The GPS receiver receives coded GPS signals, decodes them, and calculates a position. This position is then trans- mitted to the user; in the case of Landsat-D, the user is the on-board computer. The Shuttle Orbiters will also be equipped with GPS receivers. An Apple in Orbit The shirt-sleeve environment of the Spacelab reduces the stringency of re- quirements on equipment. For use not critical to the mission, standard com- mercial hardware can be used. In fact, one of the first Spacelab flights will have an experiment controlled by an Apple II Microcomputer system. The Apple will monitor an experi- ment in plant growth in the zero- gravity environment and will collect data for recording and transmission. Although the Apple has been adapted for use with other equipment, it is basically the same Apple that is com- mercially available. The use of micro- computer systems as dedicated exper- iment controllers aboard spacecraft is expected to increase rapidly. ■ References 1. Adelman, A and A Kemp. "Space Sta- tion Information Management," IEEE Transactions on Aerospace and Elec- tronic Systems, Volume AES-6, Number 6, November 1970, page 746. 2. Aranguren, R and W Langseth. "A Microprocessor Controlled Interface for Digital Satellite Systems," International Conference on Communications, Con- ference Record, Volume 2, IEEE, 1977. 3. Arens, P. "Application of Microproces- sors to Spacecraft Synthetic Apecture Radar Processing," Proceedings of the International Telemetering Conference, 1978. 4. Campoli, C and P Brede. "Microproces- sors for Satellite Telemetry: A Universal Approach," Proceedings of the Interna- tional Telemetering Conference, 1 976. 5. Carlan, A, R Constant, and R C Lekvan. "Testing Embedded Microprocessors — Space Application Requirements," Com- puters in Aerospace Conference, November 1977, American Institute of Aeronautics and Astronautics, paper 77-1399. 6. Charlton, C. "The Control of a Hard X-ray Imaging Spectrometer On-board the SMM Using Two Mutually Redundant Microprocessors," Journal of the British Interplanetry Society, Volume 32, February 1979. 7. Cliff, R. "The SDP-1 Stored-Program Computer," IEEE Transactions on Aero- space and Electronic Systems, Volume AES-4, Number 6, November 1968, page 864. 8. Dogan, Pierre P. "Spaceborne Software Engineering: An Approach to Attaining Reliability," Charles Stark Draper Lab- oratory, Flight Mechanics/Estimation Theory Symposium, Goddard Space Flight Center, May 5/6, 1979. 9. External Interface Specification and User's Guide, Multi-Mission Modular Spacecraft, S-700-11, a publication of Goddard Space Flight Center. 10. Fernandez, M. "A Review of DOD and NASA Computer Standardization," AIAA paper 77-1423, AIAA/NASA/IEEE/ACM Computer in Aerospace Conference, October/November, 1977. 1 1 . Gunzenhauser, G, E Wlaka, and D Zago. "A Microcomputer Based System for On-board Attitude Control Applications," Journal of the British Interplanetary Society, Volume 32, February 1979. 12. Hecht, H. "Fault Tolerant Computers for Spacecraft," AIAA Journal of Space- craft, Volume 4, Number 10, October 1977. 13. Holiomb, L "Overview of NASA's On- board Computing Technology Program," in Proceedings of Compcom, 1980, IEEE Number 80CH1491-OC. 14. Jurison, J et al. "Design Considerations for Aerospace Digital Computers," Computer Design, Volume 13, Number 8, August 1974. 15. Kida, T, O Okamoto, and Y Ohkami. "Synthesis and Development Procedure of Microprocessor Software Program for Spacecraft Digital Attitude Control," Japan Society for Aeronautical and Space Science Transactions, Volume 21, February 1979. 16. Knobe, B. "Flight Languages ADA vs. HAUS," 1979, AIAA paper 79-1988. 17. Koczela, L and G Burnett. "Advanced Space Missions and Computer Systems," Volume AES-4, Number 3, May 1968, IEEE Transactions on Aero- space and Electronic Systems. 18. Lesh, F and P Lecoq. "Distributed Microprocessors for Spacecraft Control and Data Handling," Technical Papers, Western Electronic Show and Conven- tion, 1976, Volume 20. 19. Martin, F and R Battin. "Computer-Con- trolled Steering of the Apollo Space- craft," AIAA Journal of Spacecraft, Volume 5, Number 4. 20. Medin, A, D Cavanaugh, and S Cades. "Computer-Managed Laboratory for Space Applications," AIAA Journal of Spacecraft, Volume 5, Number 10, October 1968, page 205. 21. O'Donnell, L. "On-board Computers" from Handbook of Astronautical Engi- neering, Koelle, editor. New York: McGraw-Hill, 1961, section 13.12. 22. Plisson, P. "Design Concepts for a Highly Reliable Multiprocessor System for Communication Satellites," Proceed- ings of the International Telemetry Con- ference, 1977. 23. Proceedings of the AIAA Aerospace Computer Systems Conference, AIAA, Los Angeles, California, September 8-10, 1969. 24. Redman, P and J Kasser. "Distributed Processing on Satellites." Computers in Aerospace Conference, AIAA Paper 77-1377. October/November 1977. 25. Reijns, G. "Recent and Expected Devel- opments in- Computers for Satellites," British Interplanetary Society Journal, Volume 31, December 1978. 26. Rennels, D. "A Distributed Micropro- cessor System for Spacecraft Control and Data Handling," at IEEE and ERA Electronic Show and Convention, Chicago, November 8 to 10, 1977. 27. Rennels, D. "Computers for Planetary Spacecraft," Proceedings of Compcom, IEEE, Spring 1980, 80CH1491-OC. 28. Rubey, R. "Higher Order Languages for Avionics Software — A Survey, Sum- mary, and Critique," IEEE, 1978, CH1336-7/78. 29. "Spaceborne Digital Computer Sys- tems," NASA-SP8070, March 1971, Space Vehicle Design Criteria (Gui- dance and Control). Available from Na- tional Technical Information Service, US Department of Commerce, 5285 Port Royal Road, Springfield, VA 22151. 30. Stables, E and C Creveling. "Spacecraft Computers for Scientific Information Systems," Proceedings of the IEEE, Volume 54, Number 12, December 1966. 31. Styles, F, T Taylor, M Tharpe, and C Trevalthan. GSFC X-562-67-202, July 1967, Goddard Space Flight Center. 32. Total Dose Testing of Several Types of MOS Microprocessors, IEEE Transac- tions on Nuclear Science, NS-25, Number 6, December 1978, 1649-1651. 33. Vahey, M. "High-level Language Oriented Aerospace Computer," IEEE CH 1449-8/79. 34. Velde, W, G Bentley, J Fagan, and W McDonald. "On-board Computer Re- quirements for Navigation of a Spinning and Maneuvering Vehicle," AIAA Jour- nal of Spacecraft, Volume 6, Number 1 2, December 1969. 35. Woldrich, R. "Multi-Micro Computers for High Data Rate Processing," Com- puters in Aerospace Conference Adden- dum, 1977, AIAA 1390. 144 September 1981 © BYTE Publications Inc Circle 21 on Inquiry card. ■1 ^m b^h 3lnC6 their introduction in mid-1980, the Anadex high resolution DP 9500 Series matrix printers have set new standards for printer quality and performance. All models feature the rugged Anadex 9-wire print head that combines long life with resolutions of 72 dots/inch vertical and up to 75 dots/inch horizontal. With this kind of resolution, final ine graphics (under data source con- trol) and razor sharp characters are pluses built inlo Performance Plus The full standard ASCII 96 character set, with de- scenders and underlining of all upper and lower case letters, is printed bi-directionally, with up to 5 crisp copies, at speeds up to 200 CPS. Models DP-9500 and DP 9501 offer 132/158/176 and 132/165/198/220 columns respectively, Print densities are switch or data-source selectable from 10 to 16.7 characters/inch. All char- acters can be printed double-width under communi- cations command. Features Plus As standard, each model features forms width adjust- ment from 1.75 to 15.6 inches, shortest-distance sensing, full self-test, 700 character FIFO buffer (with an additional 2048 characters, optional), and a quick Change, 6 million character life ribbon, Quality Plus Beyond the built-in performance of the grafixPLUS series printers, the engineerod-in quality and support are equally important. The result? Approval of both UL and FCC, Class A; operating noise levels under 65dbA; and a nationwide service organization second to none. To see for yourself why the grafixPLUS printers offer more pluses for your printing dollar, contact us today. Interface Plus Standard in all models are the three ASCII compatible' interlaces (Parallel, RS-232-C, and Current Loop). Also standard is a sophisticated communications interlace to control Vertical Spacing, Form Length and Width, Skip Over Perforation, Auto Line Feed, X On/Oil, and lull point-to-point communications. the plus in printers Made in U.S.A. for the World ANADEX, INC. • VH2.5 l)o',olu Av<;nu<; • Chalsworlh, Oilitormo Vl.'ill, USA • \<:\u\.Unrv; f/l,')) WMHOIO • IWX VK ) A'M 2 AM U.S. SALES OFFlCES.',< ii i tos©,CA£4< >8)247 3933 • Irvine, CA (713) 557 Q457 • Wakefield, MA (617) 245 9160»Au*tln, rx (512) 327 w ) ANADIX. HI) • W8QV8I House, Station Road • Hook, Basingstoke, Hants R( (27 9JY, I naland • lot Hook (025672) 34< )1 • telex 858762 ANAOI X I I Software Review Misosys Software's DISKMOD Put Radio Shack's Editor/ Assembler on Disk Steve Hughes, 5831 Hillside Dr, Doraville GA 30340 If you have bought a floppy-disk drive for your Radio Shack TRS-80 Model I and want an editor and assembler package that uses the disk, you will be interested in DISKMOD. The only problem with just buying the disk- based Radio Shack Macro Assembler is the $100 price tag. This expense is particularly annoying if you own and are satisfied with Radio Shack's cassette-tape-based Editor/ Assembler. The DISKMOD program from Misosys Software takes the cassette-based Editor/Assembler and modifies it to reside on disk and to use disk files for most I/O (input/output) operations. You can save about $50 by buying DISKMOD and the Radio Shack cassette Editor/Assembler, or $80 if you have the cassette Editor/Assembler. I am not saying that the Misosys- modified cassette Editor/Assembler is the equivalent of the disk-based Macro Assembler. It isn't. But if you are not doing extensive programming in assembly language, you may not need the extra features contained in the Macro Assembler. I use Z80 assembly language for writing utility pro- grams and an occasional subroutine, when I need a function that BASIC can't perform with enough speed. Aside from that, all my programming for the TRS-80 is done in BASIC. Since I already owned the cassette At a dance Name Format DISKMOD Cassette tape Purpose Language Upgrade the Radio Shack Z80 assembly language cassette-based Editor/Assembler to a disk- Computer based Editor/Assembler TRS-80 Model I Level II with 32 K bytes of memory, Manufacturer a floppy-disk drive, and the Misosys Software Radio Shack cassette 5904 Edgehill Dr Editor/ Assembler Alexandria VA 22303 Documentation Price 14-page 8'/2- by 11-inch $19.95 loose-leaf pamphlet Editor/Assembler (hereafter referred to by its file name, EDTASM), the modification program looked good to me. The package I purchased consisted of a single tape cassette containing two versions of the program (one for EDTASM 1.1, the other for EDTASM 1.2) and a 14-page user's manual. The cassette is warranted for 90 days on a replacement-only basis. (This must be what the registration form is for, since no other explanation of its use is given.) The DISKMOD program moves the EDTASM pro- gram to disk after modifying it extensively. The modifications: • allow loading and saving source programs and data to a disk file • allow the object code to be written to a disk file • allow you to move blocks of source data in the text buffer • provide a replace-string function for the editor • allow you to see how much free space is left in the text buffer • allow you to get a disk-directory listing from EDTASM • allow you to kill a file from EDTASM • allow use of the Clear key • enable you to paginate listings • let you sort the symbol table before printing it • change the screen scrolling to provide 15 lines of text on the screen • allow you to reenter EDTASM without losing the con- tents of the text buffer • enhance the B command and the DEFM assembly out- put Your next question is, "What do I have to do to use the DISKMOD program?" First, you must have a system with 32 K bytes of memory and a copy of the Radio Shack cassette Editor/Assembler. The DISKMOD pro- gram works with either version 2.2 or 2.3 of TRSDOS and with most other TRS-80 disk operating systems. The instructions for loading and using the DISKMOD program are simple and straightforward. I found only 146 September 1981 © BYTE Publications Inc Teachyour littleAppletotalk toWfesternUnion, Telex andTWX. Albany Omaha Micro-Telegram™ lets your Apple II™ computer access Western Union™ services, worldwide. You can send Mailgrams.® Send and receive TWXf Telex, and international cables. Receive Infomaster® up-to-the-minute news, stock, foreign exchange, gold, futures, sports, and ski reports. Use your Apple™ to wire money. To send flowers. To check the snow at Sun Valley. To see what the Yen is selling for. To contact over 900,000 TWX and Telex subscribers around the world. And because it's more intelligent than a mechanical Teletype™ machine, Micro- Telegram lets you edit messages right on the screen, sends them automatically without you in attendance, keeps subscriber directories and distribution lists, prints when you want it to, and asks you in plain English for your commands. Besides, it doesn't clatter and churn out reams of paper. Call our toll-free number today. And make your little Apple heard 'round the world. MICROCOM We make little computers talk big. Call 800-547-5995, ext. 188, toll-free, for the Micro-Telegram -Apple dealer nearest yOU. Dealer inquiries invited. Microcom, Inc., 89 State Street, Boston, MA 02109. (617) 367-6362 Apple and Apple II ore trademarks of Apple Computer, Inc. Western Union, Infomaster and TWX are trademarks of Western Union, Inc. Teletype is a trademark ofthe Teletype Corp. Circle 218 on inquiry card. Listing 1: Output of the PD (List Directory) command. 00018 FREE GRAINS • DIRECTORY - DRIVE TAPEDISK/CMD 00512 LOWER/CMD 00256 COPY/CMD 03072 TEST1/CMD 01536 EDTASM/CMD 05888 RSTERM/CMD 00768 KSRTEST/CMD 00256 TRSDOS -09/17/80 one slight problem: the command provided to write the DISKMOD program to a disk file is incorrect. It reads: F DISKMOD/CMD 7500 8ACA 7F70 It should read: F DISKMOD/CMD:0 7500 8ACA 7F70 With this correction, anyone can use the program suc- cessfully. The process takes about ten minutes. When you're finished, you can type the command EDTASM under TRSDOS and have the Editor/Assembler speedily loaded from disk into memory. You notice a difference in the Editor/ Assembler instantly. It now prompts for memory size. This lets you reserve high memory for peripheral-device drivers or any other subroutines. One pleasant surprise concerns the printer driver. The modified program uses the same DCB (device control block) and ROM (read-only memory) printer driver as Level II BASIC. If you have a special printer driver for use with BASIC, it also works with the Editor/ Assembler. When you have answered the memory-size question, you are back in normal working mode. The only command I will mention is the PD, or List Directory, command. It gives the name and size of each normal file on the disk, as well as the amount of free space on the disk. This information is particularly useful when you are attempting to squeeze a new file onto a nearly full floppy disk. Listing 1 shows a sample of the information you receive. The other new commands work quite well. Explicit prompts are used for most of them, making it easy for the beginner to use them. The manual explains each new command in detail and notes any changes made to the standard commands by the DISKMOD program. The package works as advertised and all the com- •mands function. It is possible that some problems will occur as I use the modified Editor/Assembler more exten- sively. In my experience, major modifications made to an existing program generally cause some minor bugs. The modified program has worked satisfactorily so far. If you are considering a move to a disk-based Editor/ Assembler, but dislike the cost of Radio Shack's Macro Assembler, I strongly recommend the combina- tion of the Misosys DISKMOD and the Radio Shack cassette Editor /Assembler programs. ■ 148 September 1981 © BYTE Publications lnc EPSON PRODUCTS MX80/70 FRICTION FEED KIT by Orange Micro HERE AT LAST! A friction feed kit for your EPSON MX80/70. The kit allows the user to convert his Epson printer to a friction feed and pin feed mechanism. The friction feed will accept single sheets of your letterhead, or mul- tiple copy forms such as invoices with up to 4 part carbon copies. The pin feed replaces the adjust- able sprocket mechanism. It allows use of 9 1 /2" wide continuous fan- fold paper which is an industry standard size. No drilling required. Installation takes about 30 minutes. All parts are included with easy to follow instructions. 75. 00 DEALER INQUIRIES INVITED EPSON MX80 • 9 x 9 dot matrix • Lower case descenders • 80 CPS • Bidirec- tional, Logic seeking • 40, 66, 80, 132 columns per line • 64 special graphic characters: TRS-80 Com- patible • Forms handling • Multi- pass printing • Adjustable tractors. MX80 (List $645) $ CALL MX80 Dot Graphics Upgrade (List $95) SCALL EPSON MX70 • Super low-priced dot resolution graphics • 5 x 7 dot matrix • User replaceable printhead • Top of Form. MX70 .(List $445) SCALL EPSON MX80 FT MX80 F/T . • Same basic features as the MX80 • PLUS friction feed for single sheets • and adjustable tractors. (List $745) SCALL APPLE INTERFACE For Epson The Grappler interface card is the first to provide on-board firm- ware for Apple high resolution dot graphics. No longer does the user need to load clumsy software routines to dump screen graphics — it's all in a chip. Actually, it's our E-PROM, and it is replaceable to accommodate the Anadex, Epson MX80 & MX70, IDS Paper Tigers, Contronics 739, and future graphics printers. The Grappler™ accepts 17 software commands including Hi-Res inverse, 90° rotation, double size, and much more. $ 165. 00 Includes Cable DEALER INQUIRIES INVITED Orange micro "THE COMPUTER PRINTER SPECIALISTS" UP TO 25% DISCOUNTS! — SAME DA Y SHIPMENT! /3) CENTRONICS 739 (u ^— < With Graphics and RADIO SHACK 1 NE PRINTER IV J Word Processing Print Quality VISTA — C. ITOH Daisy Wheel Letter Quality • 18 x 9 dot matrix; suitable for word processing • Underlining • proportional spacing • right margin justification • serif typeface • 80/100 CPS • 9 1 /2" Pin Feed/Friction feed • Reverse Platen • 801132 columns • Top of form CENTRONICS 739-1 (Parallel) (List $995) $ Call CENTRONICS 739-3 (Serial) (List $1 045) $ Call ANADEX Dot Graphics, Wide Carriage • 11 x 9 dot matrix; lower case descen- ders • 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. ANADEX 9501 (List $1650) $1350 AXIOM Dot Graphics, Low Price • Dot addressable graphics • 70 CPS • 12 characters per inch • 80 columns • adjustable tractors • 3 part copies • Manufactured by Sieko • Parallel, RS232 serial, IEEE-488 interfaces available. AXIOM GP-80M (List $399) $349 IDS PAPER TIGERS Dot Resolution Graphics, quality print, speed • 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). IDS 445G 7 wire printhead, graphics (List $895) IDS 460G 9 wire printhead, graphics (List $1394) IDS 560G 9 wire, wide carriage, graphics (List $1794) CALL FOR INFORMATION & CATALOG (800) 854-8275 CA,AK, HI (714) 630-3322 RETAIL PRINTER STORE Store #1 3150 E. La Palma, #l, Anaheim, CA (714)630-3622 Store #2 13604 Ventura Bl., Sherman Oaks, CA (213)501-3486 Store #3 COMING SOON?? Store Hours: M-F 10-6 Sat. 10-4 • 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 $1350) $ Call MALIBU165 The Small Business Printer; Letter Quality & Speed. •10x9 dot matrix • Letter quality print; Lower case descenders • High speed; 165 CPS, Bidirectional, Logic seeking • Wide car- riage • Vertical forms control • User programmable character set • Dot Resolution Gra phics. NEC SPINWRITER High Speed Letter Quality • 55 CPS • Typewriter quality • Bidirectional • Plotting • pro- portional spacing. \ 5510-5 RO, Serial, w/tractors (List $2995) $2675 5530-5 RO, Parallel, w/tractors (List $2970) $2650 TELEVIDEO CRT'S! AT DISCOUNT PRICES! QUANTITY PRICING AVAILABLE TVI910 TVI912C TV I 920C TV I 950 } Please Call Toll Free Prices are too low to advertise PRINTERS MALIBU 165wide carriage, graphics, letter quality .. (List $2495) $1975 QUME 5/45 typewriter quality (List $2905) $ 2559 INTERFACE EQUIPMENT ■ ORANGE INTERFACE for Apple II parallel interface board & cable $ 110 I MICROTRONICS Atari parallel interface $ 69 ATARI 850 Interface module, serial/parallel $ 199 TRS-80 CABLES to keyboard or Exp. interface $ Call | ^H NOVATION D-CAT direct connect modem S Call WM Orange micro * inc. 3150 E. La Palma, Suite G, Anaheim, CA 92806 Phone order WELCOME; same day shipment. Free use of VISA & MASTER CARD. COD's accepted. Manufacturer's warranty included on all equipment Prices subject to revision. At Orange Micro, we try to fit the right printer to your application. Call our printer specialists lor free consultation. circle 268 on Inquiry ca The Converter that transforms your electronic typewriter into a computer printer. #> No modifications to the typewriter ^* Does not affect normal typewriter functions & All typewriter functions accessible by computer ^ RS232C, IEEE and parallel interfaces available ^ KSR version turns typewriter into a computer terminal ^ Fully assembled, tested and burned in NEW! NOW AVAILABLE OLIVETTI PRAXIS 35 TYPEWRITER , • + '" : CONVERTER TP35 = DAISY WHEEL PRINTER FOR LESS THAN $1000. Prices start as low as $275. CONTACT YOUR LOCAL OFFICE EQUIPMENT DEALER OR VERTICAL DATA SYSTEMS INC. FOR FURTHER DETAILS. m Vertical Data Systems Inc. 1215 Meyerside Dr., Unit 2A, 4nww/ Mississauga, Ontario, vvv Canada L5T1H3 (416)671-1752 Dealer inquiries invited Software Review MINCE A Text Editor Christopher O Kern 201 I St Apt 839 Washington DC 20024 A text editor is probably the most personal program on a personal computer system. The average user spends a good amount of time communicating with the editor — entering or altering programs, data, or text. Different users, with different applications, often have different ideas about how they want an editor to work, a fact which accounts for the large number of editors on the market. MINCE is one of the newer entries into the software market for 8080-family computers that use the CP/M op- erating system. MINCE is modeled on a large-system editor, called EMACS, which was developed at MIT (Massachusetts Institute of Technology). Its authors say that MINCE stands for "MINCE Is Not Complete EMACS"; nevertheless, it has a lot to offer. It can do all the usual text-editing functions — insert or delete characters, words, and blocks of text, move text around, and search for and replace strings — as well as perform a number of other operations that are not generally avail- able in microcomputer editors. MINCE's features include the ability to read, create, and write multiple-disk files, to move text among dif- ferent files quickly and easily, to automatically transpose characters and words, and to execute familiar operations in unusual contexts. For example, it can move the cursor by sentences or paragraphs, fill lines out to a specified length one paragraph at a time, capitalize or change the case of words without retyping them, and delete just the whitespace between words or characters as well as the words or characters themselves. Command Structure Despite the large number of commands in MINCE, the editor functions coherently. Command types are grouped logically so that one command sequence is used for a group of commands that affect textual units such as letters and lines, and another command sequence is used for a group of commands that deal with lexical units such as words and sentences. Where possible, the same mne- monics are used for similar operations at these different command levels. For example, the command to move the cursor forward one letter is Control-F, and the command 150 September 1981 © BYTE Publications lnc Circle 378 on inquiry card. Circle 107 on inquiry card. "Our goal at The Denver Software Company is to translate the advances in high technology — symbolized by the Space Shuttle triumph — Into practical, problem-solving microcomputer programs for small business and home use." -\»^ (/- f* Microcomputers Are The Door To The Future. We Have T Finally, there's an accounting package available for most microcomputers — from the least expensive to the top-of-the- line — that works the moment the machine is switched on. Language, programs, everything needed for accurate bookkeeping is built into the software, eliminating the need for programming skills or expensive equipment add-ons. The FINANCIAL PARTNER™ is a comprehensive financial pack- age that takes the headache out of bookkeeping. With general ledger, cash receipts, accounts payable, and check- printing capability, this system also provides standard fi- nancial reports. In addition, the FINANCIAL PARTNER™ comes with a detailed user's manual con- taining basic bookkeeping instruc- tion. By automatically sorting and posting accounts, the FINANCIAL PARTNER™ saves you valuable time and is a complete guide to money management for your home or very small business. At $175, it's worth its weight in gold. Also from The Denver Software Company: The PASCAL TUTOR™, a computer assisted course in UCSD Pascal*. This complete software package uses the microcom- puter to teach this powerful new programming language. $125 for this fast, easy way to learn versatile UCSD Pascal*. * UCSD Pascal is a trademark of the Regents of the University of California. Products available from your local dealer. THE DENVER SOFTWARE COMPANY MANUFACTURERS OF MICROCOMPUTER SOFTWARE The I i those kn ules dra debugg money as i PROGRAM geable about ly shorten the ograms — by II as time. 00 E. Jewell Ave. ler inquiries welc ALTOS BUSINESS € " \f£D ^ . k K PRODUCED IN THE HEfiRT OF SILICON VFULEY, CRUFORNIR U.S.fi. ■gran "S^T^^mh ■jjiq HHj - - - - ■ "fWC" "J58f 2^5 1 g>ji2 •jgg ■f^MMMM^MmO Now— A four station, hard disk business computer with letter quality printer, terminals and get-rolling software for less than $15 a day.* •Price approximate and may vary in your area. Daily lease based on: $17.(300 principal. 20%annual interest, 5-year term. Includes: Altos ACS8000-10 computer, letter quality printer, four precision terminals and get-rolling software. Does not include tax. installation, training and maintenance. Introducing the Altos Business Computer Special. The most powerful, reliable, easy-to- use system in its price range. And Altos now offers on-site, nationwide service. The hardworking engine of our system is the Altos ACS8000-10 computer. It can cost-effectively hook-up with from one to four stations, as your needs demand. Its rapid access, 10 MByte Winchester hard disk is capable of storing a 3,000 page load. IMPUTERSPEC1AL H J r- Our get rolling business soft- ware package includes multi-user systems software, Wordstar'" for word processing and Microplan* for business analysis. And when you need more, your local Altos representative can route you through to hundreds of other business and accounting pro- grams, to meet virtually any requirement. Plus Altos also lets you communicate with other computers, mainframes, and even allows networking. Circle 16 on Inquiry card. Get on the right track! Join thousands of professionals, insti- tutions and businesses who rely on Altos computer systems. Call our toll free number or write today for the Altos sales and service depot nearest you. All aboard! Packed with fresh ideas for business Wordstar is a trademark of MicroPro International Corp. Microplan is a trademark of Chang Laboratories. Inc. © 1981 Altos Computer Systems AlsXX> COMPUTER SYSTEMS 2360 Bering Drive San Jose, California 95131 800-538-7872 (In Calif. 800-662-6265) to move it backward one letter is Control-B, while the analogous commands to move the cursor across words are Escape-F and Escape-B. As the previous example implies, MINCE does not use the cursor control or other special function keys available on many terminals. Commands are entered as control characters, as escape sequences (the escape character fol- lowed by one or more additional characters), or as con- trol sequences (a control character followed by another control character or a printing character). Most com- mands can be executed reiteratively by preceding them with a numerical argument. In the usual operating mode, text is self -inserting: characters typed at the console will be inserted into a file rather than written over what is already there. An optional page mode provides the more common arrangement in which typing at the console replaces any text at the current cursor position. For convenience, the text being edited is assumed to contain only a single "newline" character between lines. While this character is displayed only in the sense that it moves the text following it down to the next line, it is otherwise treated in the same manner as any other char- acter. But the files written by MINCE conform to the CP/M convention of having both an ASCII (American Standard Code for Information Interchange) carriage- return character and a line-feed character at the end of each line. Thus they are completely compatible with other CP/M programs, such as the CP/M-resident TYPE command. MINCE will display control characters embedded in the text except for those, such as newline and tab, to which the text editor responds. Control-A, for example, would appear on the display as t A. MINCE provides some rather arcane commands, such as one that moves the cursor to the next line and indents it to correspond with the indentation that started the previous paragraph (helpful for writing code in struc- IMPORTS EPSON MX-80 Price Breakthrough - Coll! 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Warranties Included on all products. Personal checks take 3 week to clear. SuperSoftfs Optimizing The SuperSoft "C" compiler supports most of version 7 Unix standard "C". Several special and widely desired features are supported, including: • Macro expansions via the #define statement. • Include files using the inc- lude statement. • Inline assembly code is supported with the tiasm and #»ndasm. • The object code may be ROMed. • Programs may be ORGed for any location. allocation is supported, both by the compiler and in user programs. (That is, the functions 'alloc* and 'free' are provided with the compiler.) SuperSoft "C" is a two pass compiler. The first pass of the compiler produces an intermediate code (U-code, for Universal code). Pass two contains both the translator and the optimizer. The intermediate code is optimized and assembly code is output to file. The optimizer typically results in 40% code reduction. This means that compiled object code will run nearly as fast as that which was written in assembler. An important feature of the compiler is that aseembly code Is produced. This means that "hand optimization" of critical sections iS' possible. Also, the Inline coder allows easy insertion of assembly language routines. With the compiler comes the complete source code to the I/O libraries. These libraries are equal to or better than any that exist for the Functions Included: open close read write seek tell fopen create putc • getc flush The Seek command supports absolute, relative from front, and relative from end of file. Fopen includes fcreat. Also included with the compiler are numerous sample .programs and a complete library of useful functions. for CP/M Compile time options include listing file, console outpu.t, syntax checking and others. Requires: 48K CP/M, (more recommended) "C" compiler: $200.00 Manual only: $ 20.00 Z8000 cross-compiler: $500.00 (CP/M to Z8000 code, requires Z8000 assembler) Source code for in-house use only: $5,000.00 CP/M formats: 8" soft sectored, 5" Nor- thstar, 5" Micropolis Mod II, Vector MZ, Superbrain DD/QO Apple II + o 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 'Unix registered trademark Bell Laboratories tured programming languages). Yet it is possible to make MINCE do useful work, by learning only a handful of the most common commands and picking up others as your sophistication and requirements grow. Multiple Files MINCE lets the user work on, or from, multiple files. Each file is read into a logically separate buffer area from which it can be operated on independently. It is also possible to move text from one file to another, as when copying blocks of text or program source code. The vir- tue of having the ability to deal with multiple files may not at first be obvious (at least it wasn't immediately ob- vious to me), but, now that I have done a bit of experi- menting with multifile editing, I think that I would really miss that feature. Of course, ignorance is bliss: it didn't bother me that I could work on only one file at a time when I was using CP/M's ED program or any of the other editors I have used at one time or another. As I write this, I am working with three files. The first contains the text you are reading at the moment. The sec- ond contains random observations about MINCE that I entered as I learned to use the program. The third file contains a description of all the MINCE commands — conveniently provided on the MINCE distribution disk — that I keep ready for reference. As I go along, I am copy- ing some of my earlier observations almost verbatim. After editing the pertinent block of text, I just transfer it into the main file (the one I am using for this article). AVAILABLE TODAY from MSD: the XENIX™ Operating System, Microsoft's Adaption of Bell Laboratories Time-Tested UNIX™ Version 7 Operating System . MSD provides this comprehensive line of products for the UNIX community: ■ XENIX Operating System ■ Screen Oriented Text Editor for VT-100 Compatible Terminals ■ Database Manager and Report Generator Which Will Easily and Efficiently Control Large Accumu- lations of Information ■ Accounts Receivable System Which Can Be Used to Monitor and Control Receivables in Order to Improve Cash Flow ■ Uni-Calc™ - An Electronic Spreadsheet Which Makes Financial Analysis, Forecasting and Business Planning Easier In addition to reliable Software pre-config- ured for your Hardware, MSD will provide complete user support by: ■ Answering your telephone questions ■ Providing new releases as available ■ Supplying you with the best Hardware for your UNIX requirements » A MSD Corporation ^4^. 2449 Camelot Court, SE % I^i Grand Rapids, Ml 49506 (616)942-5060 D MANAGEMENT SYSTEMS DEVELOPMENT Uni-Calc, UNIX and XENIX are trademarks of MSD Corp., Bell Laboratories and Microsoft respectively When I am finished writing, I will save the article on disk, replace the original random observations file with the edited version, and do nothing at all with the list of com- mands, which will remain on the disk in its original form. If I wanted to, I could save the edited random observa- tions as a new file, so both the original and edited ver- sions would be available on the computer's file system. It is also possible to display two files simultaneously. MINCE splits the video screen horizontally, creating two separate windows, one into each file. Each window begins at half the screen size, but can be expanded or con- tracted more or less arbitrarily. At the moment, for ex- ample, I am looking at this text in the top half of the dis- play and at my earlier comments on the use of windows in the bottom half of the display. If I wanted to look at something in the file containing the list of commands, I could place that file in the bottom window without dis- turbing the display of the text I am writing. Since the win- dows are entirely independent, it is possible to move to the next page of one file while writing, editing, or main- taining the cursor position on another. Status information is continuously displayed at the bottom of the screen. This includes the name of the file currently being edited and a percentage figure indicating how much of the existing file is behind the current cursor position (a nice feature). Among the other status indica- tors is one that tells the user whether a particular file has been altered. If it has, MINCE won't return to the com- mand level of the operating system without offering an opportunity to save the altered file on disk. Speed of Operation For all its impressive flexibility, MINCE is not without its flaws, some of which it shares with other editors run- ning in microcomputer environments. First, and worst of all, MINCE is slow. The editor doesn't seem to lose char- acters; frequent checking for keyboard input and the pre- sence of a large type-ahead buffer ensure that. But MINCE can't update the screen fast enough to keep up with a fast typist. It took me quite a while to get used to the fact that one or more characters I had typed, especially when I was using multiple deletes to back- space/erase to an earlier point on a line, had already been entered in the file, but were still waiting to appear on the screen. There are commands in MINCE's repertory that I can use to get around this particular problem. But I ex- pect characters to appear as soon as I type them, and MINCE simply can't accommodate me. MINCE is also slow in performing certain updating functions. For example, it starts a new "page" after the user types past the last visible line on the screen. Many other editors simply scroll the previous text up one line, which is simpler than removing a whole page and replac- ing it with a new one because scrolling can be performed by the terminal hardware. All the editor has to do, then, is keep track of which lines are still visible on the screen. You can keep typing while MINCE figures out what to do next, and anything you type will eventually be displayed. But it may take several seconds before that happens. 156 September 1981 © BYTE Publications Inc Circle 249 on inquiry card. Reference the Future... DIGITAL PRESS ,JSS» EARiy. ORDERING INFORMATION Ten percent discount when ordering two or more copies. Shipping and handling fre when order is prepaid by check or charge card. QUANTITY TITLE PRICE* Mail to: Digital Press Order Fulfillment Digital Equipment Corporation 12-A Esquire Road Billerica, MA 01862 Subtotal _ Discount . Sales Tax _ Total _ "All prices quoted are U.S. only. Contact your nearest office of Digital Equipment Corporation. Educational Services, for prices outside the U.S. Prices subject to change without notice. Name Add res; City _ _ Company/School -Zip CHECK OR CHARGE CARD REQUIRED ON ALL ORDERS UNDER S50. Make Checks Payable to Digital Equipment Corporation NEW! LEARNING WITH COMPUTERS Bork A comprehensive overview for using the computer as a teaching device to build a more responsive learning environment. 1981, hardbound, 300 pages, S28.00 NEW! THE THEORY AND PRACTICE OF RELIABLE SYSTEM DESIGN Siewiorek and Swarz Shows how to combine economics with design and cost modeling with reliability modeling in hardware system design. 1981, hardbound, 700 pages, S45.00 NEW! From ENIAC To UNIVAC: An Appraisal of the Eckert-Mauchly Computers Stern Examines the pioneering achievements of J. Presper Eckert and John W. Mauchly: the ENIAC, the EDVAC, the BINAC, and the UNIVAC. 1981, hardbound, 286 pages, S21.00 NEW! INTRODUCTION TO DECSYSTEM-20 ASSEMBLY LANGUAGE PROGRAMMING Gorin Examines the instruction set, assembly language, applications and application techniques, and system features of the DECSYSTEM-20. 1981, paperbound, 576 pages, S35.00 . Check Included. Charge Card Acc'l No. Authorized Signature Master Charge. VISA Please place me on y uir mailing list. BYTF-81 COMPUTER ENGINEERING: A DEC View of Hardware Systems Design Bell, Mudge and McNamara Shows how evolving technologies, marketplace economics, and manufacturing costs influence computer engineering. 1978, hardbound, 585 pages, $26.00 COMPUTER PROGRAMMING AND ARCHITECTURE: The VAX-11 Levy and Eckhouse, Jr. Focusing on the VAX-11, this unique book offers a comprehensive system viewpoint to the programming and organization of today's computers. 1980, hardbound, 407 pages, $28.00 DATA PROCESSING TECHNOLOGY AND ECONOMICS, Second Edition Phister, Jr. Complete coverage of DP operating costs, programming costs, system and software performance and reliability, time sharing economics, and more. (Co-published with Santa Monica Pub. 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(Co-published with American Mathematical Society) 1979, paperbound, 360 pages, $12.00 mmm We change the way the world thinks. Circle 116 on inquiry card. I suspect the slowness is a by-product of two of MINCE's undeniable virtues: the way it was written and the way it updates the screen. MINCE was written in the high-level language C, a general-purpose language devel- oped at Bell Laboratories that is often used for system- level programming (see "The BDS C Compiler" by Christopher Kern in June 1981 BYTE, page 356). Since it is written in a high-level language rather than in an assembly language, MINCE is easy to transport to other processors. This portability means that as long as MINCE's authors stay in business, someone who buys new hardware is likely to be able to buy a version of MINCE to run on it. (Perhaps those responsible for MINCE will publish their source code if their business goes under.) But the use of a high-level language on an 8-bit microcomputer inevitably imposes a considerable penalty in speed. To update the screen, MINCE uses standard cursor positioning facilities rather than the idiosyncratic hard- ware page editing capabilities available on some smart terminals. This means that the editor will run on just about any terminal or stand-alone computer system available. It takes time, however, to move a cursor around and to update a display serially, even if the ter- minal is running, as mine is, at 9600 bps (bits per second) . Text Swapping Another problem with MINCE is that it swaps parts of the file between main memory and disk during long pauses between keyboard entries. In the long run, this is to the user's advantage: performing this operation while , ,Af a dance Name of Software Computer Needed MINCE (MINCE Is Not 8080-family computer run- Complete EMACS) ning Digital Research's Type CP/M operating system Text editor with at least 48 K bytes of system memory and floppy- Manufacturer disk mass storage Mark of the Unicorn POB423 Documentation Arlington MA 02174 52-page user guide; (617) 489-1387 5-page installation guide; 46 pages of tutorial in- Price troduction (also included as $125 files on distribution disk) Format 8-inch, IBM format soft- Audience sector disks; other formats CP/M users requiring a by arrangement video terminal text editor Language Used 8080-family machine language m i COPY SERVICE Allenbach Ind 4322 Manchester Ave. Olivenhain, CA 92024 *v*v iV \* «— ■awi ^ ^ ff^° .<*$*> .-#&* v*v?v ,nN< 158 September 1981 © BYTE Publications Inc Circle 12 on inquiry card. Circle 400 on inquiry card. GUARANTEED RELIABLE FOR 2 FULL YEARS. Unprecedented product reliability deserves an unprecedented warranty. IMS International provides its dealers with both. Our commitment is real. We are so confident that our products are the industry standard in reliability, we stand behind them for two full years from date-of-sale to the end user. All IMS manufactured products are covered. The success of our dealers will insure our continued growth. That's why IMS International is committed to providing every IMS dealer with these distinct advantages in today's marketplace: • 2 year warranty • Low retail cost • Best margins in the industry • Protected territories • Full factory technical support • Complete system delivery in 30 days • Comprehensive advertising and promotional support For more information about IMS International's "Reliables" and our unique dealer plan, call 714/978-6966 or write us: 2800 Lockheed Way Carson City, NV 89701 Telex: 910-395-6051 INTERNATIONAL Circle 164 on Inquiry card. BYTE September 1981 159 the keyboard is inactive means that less disk swapping will be necessary at a time when the user is more active and when text swapping would really slow him down. But even though each swapping operation only takes about a second, I found the sudden onset of disk activity disconcerting. Fortunately, MINCE's configuration pro- gram allows the user to set the time delay between the last keyboard entry and the start of the swapping operation. MINCE's authors recommend a four-second pause. I found a twenty -second delay more to my liking. MINCE is a large editor not only in the number and variety of its available commands, but also in its require- ments for disk space. The editor proper requires 30 K bytes. During operation, MINCE must have a swap file available to provide space for those portions of the file(s) being edited that don't fit in the host system's available semiconductor memory. MINCE's authors say a 24 K- byte swap file is the workable minimum and recommend a 64 K-byte swap file. I evaluated MINCE and wrote this review using a 32 K-byte swap file with no serious ef- fects, although I did have to juggle my reference files as the article grew in size. (Files not currently being used can be dropped, thus freeing space in the swap file for active files.) Configuration and Documentation Selecting the size of the swap file, notifying MINCE of the characteristics of the host system's terminal, and other required set-up operations are performed by a con- figuration program that is very easy to use. The configu- ration program comes equipped with the necessary infor- mation for the terminals most commonly encountered in microcomputer systems, and it accepts user-supplied in- formation for the less common ones. The whole configu- ration process is menu-driven and provides ample oppor- tunities to correct errors or simply change one's mind. MINCE's documentation is excellent. The user manual is well organized and crisply written. In addition, two tutorial introductions to MINCE are supplied. One is de- signed for more experienced programmers, and the other is designed for the uninitiated computer user. In practice, I think the programmers' tutorial would suffice for any- one who has ever used a text editor on a computer. The general-users' tutorial claims to require nothing more than knowing how to type and how to log onto the host computer system — a claim that appears to be true. The first eight-page lesson introduces the trainee, step-by-ex- cruciating-step, to such mysteries as how to use the delete key to erase the previous character, how to move the cur- sor forward and backward, and how to quit the editor when he is finished. (But, it does not explain how to write a file to disk — that is left for another lesson). The tutorials don't pretend to cover all of MINCE's fea- tures, but anyone who is willing to work his way through them will certainly learn how to use the editor in at least a minimal fashion. Most of the tutorial material is pro- vided on disk files as well as in hard-copy form, and many of the exercises call for the user to edit the tutorial he is working from. I found some of the prose in the tutorials a bit cloying; the exercises provided a conve- nient remedy. Conclusions • MINCE has a large, well-planned command repertory. A user needs to learn only a small subset of the available commands to operate the editor; others can be learned as his requirements grow. • MINCE permits multiple files to be viewed and edited — a real convenience. Two files may be viewed simulta- neously on a split screen. • MINCE is slow in updating the video display, both during user input and during cursor movement across pages (video screens). The use of a swap file also slows editing down and results in unexpected disk activity. • MINCE is well documented. Tutorial introductions to the editor help even the novice get started easily. ■ Kj computers, yo ,'ii.h j«>wei of i he fecal Micro- Pasca!' up to 10 times faster than typical imple- mentations— with twice the memory capacity. You've got the best hard- ware for the best software around. Onboard Z80 PASCAL-100 includes a Z80 3 processor, so you can run your current software— including CP/M 4 — without modification. Ready to con- vert an application to Pascal? Do it anytime, with no disruptive hardware changes. PASCAL-100 comes complete with extensive documenta- tion—our users say it's the best around! New Generation S100 PASCAL-100 is designed for the versatile, flexible S-100 bus. Fully compatible with the new 1EEE-696 standard, yet works with nsffi •16 MM 4 bj i rkswithlfi Want to know more? on the reader service card, i or write us directly. OEH'S/DEALERS- Be sure to specify our PASCAL-100 OEM/Dealer Information Package Dig. camp Research Terrace Hill Ithaca, NY 14850 (607)273-5900 Trademark of Western Digital Trademark of University of California 'Registered Tradetnar k of Zilog, lac. 'Registered Trademark of Digiial Research 160 September 1981 © BYTE Publications Inc Circle 111 on inquiry card. SSSSSSSS33335SSSSSSSSSSSSSSS \i < HOOK 3 WINNERS $139.00 WINNER #1 ^ $159.00 WINNER #2 ^ $179.00 WINNER #3 ^ DEMAND THESE UNITS FROM YOUR DEALER! gSSSSSSSSSSSSSSS5S55SSS555SSSSS^ Data-Ed 18 Bridge Street Saiem, NH 03079 603-893-2047 (collect) Name TM-12GX Monitors at S179.00 plus 2.75 shipping TM-12G Monitors at S159.00 plus 2.75 shipping TM-12 Monitors at $139.00 plus 2.75 shipping □ Please send OEM information about your low cost custom fit smart printers. □ Check or Money Order enclosed □ COD. Orders Accepted a Bill my-a VISA-n Mastercharge Card No Address. City, State, Zip Exp. Date Signature . Bank No.. SSSSSSSSSS35SSSSW^^\SSS\ Type-'N-Talk™ has its own memory. Even the smallest computer can talk and execute programs simultaneous- ly, because Type-'N-Talk'"has its own built-in microprocessor and a 750 character butter to hold the words you've typed. Type-'N-Talk'" doesn't use your host computer's memory or tie it up with text translation. If you can hardcopy it, you can hear it. By placing your Type-'N-Talk 1 " between your computer or modem and a terminal, you can hear all the data sent to the terminal while online. Random-accessed information from a remote data base can now be seen and heard, because Type-'N-Talk'" says it all. Type-'N-Talk'"has the data switching capability that allows you to "de- select" while sending and receiving data to and from a terminal. Data switching lets you send speech and visual data independently on a single data channel. NOW Interface any way you want. Special control characters let you interface Type-' N-Talk'* in a variety of ways. Unit assignment codes allow you to daisy-chain multiple Type-' N-Talk" units. You can also have independent control of Type-'N-Talk""and your printer by using unit addressing codes. Connect Type-'N-Talk'"directly to your computer's serial interface and you can eliminate the need for additional minals. printers or additional Type-'N-Talk""units to the first Type-'N-Talk" Votrax' developed Type-'N-Talk" v to function with operator designed programs or with the new Votrax" talking software currently under development. Type-'N-Talk"'" can also be used without software. The Type-'N-Talk""unit's simplicity enables it to be used by the begin- ning hobbyist, yet its total capability can challenge the most sophisticated' TYPING Now You're Talking — just $375.00. • Text-to-speech algorithm i A one-watt audio amplifier j SC-01 speech synthesizer chip (data rate: 70 to 1 00 bits/sec.) 1 . 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Ml 48084 Circle 380 on inquiry card. wi I n TYPE-W-TAL.K ory and storage of all the known facts is essentially useless — the only way one could make use of the data would be the simplistic matching of a set of symptoms against sets of indications for each disease. This kind of approach is doomed from the start: some symptoms are less suggestive of certain diseases than others. Therefore, the system should have the ability to order specific addi- tional tests (giving preference to non- invasive ones) before attempting a diagnosis. Also, the patient's age, en- vironment, and medical history must be taken into account. Amidst all this, there must be the capability of ignoring certain facts if they are in- consistent with the most strongly sug- gested diagnosis — a patient's tennis elbow, for example, is probably unre- lated to his or her infectious men- ingitis. If the machine is to be more useful than a textbook, it must be able to do all these things, as well as provide a facility for updating its own informa- tion as often as required. In sum- mary, it must possess a measure of in- telligence. Such a system is not mere conjec- ture, by the way. One has already been created to provide diagnosis and therapy selection for two major types of diseases: blood infections and men- ingitis. Developed at Stanford Uni- versity by doctors Bruce Buchanan and Edward Shortliffe, the program, called MYCIN, has outperformed human diagnosticians in the identifi- cation and treatment of diseases in this class, not only through its accu- racy in pinpointing the pathogen, but in its avoidance of overprescribing treatment. This last accomplishment is espe- cially noteworthy, because the stan- dard clinical approach to an un- known disease involves a broad-spec- trum antibiotic attack on a wide variety of possibilities. This not only exposes the patient to potential toxic effects, but encourages the develop- ment of drug-resistant bacterial strains. (A recent Stanford University study revealed that one of every four persons in the United States received penicillin under a doctor's orders in VT 100 Owners s THE KEY TO FAST '-VI'J^.VVJ^Mbil^ (OF YOUR KED EDITOR) INTRODUCING VT 100 KEYS FOR THE KED EDITOR... ir 3-color keys will make editing faster and simpler. They're easy to install- no overlays— just pull out the old keys and push in a new set with the KED functions clearly stated. A set of 18 3-color keys — $40. Synchronics 4 Frost St./Cambridge, MA 02140 (617) 739-7710 1977 and that nearly 90% of these prescriptions were unnecessary.) A Technology Is Born For all of these reasons, along with many others ranging from the inade- quacy of standard programming tech- niques to the sheer joy of research, computer science has spawned a new discipline: artificial intelligence (AI). Actually, AI is not all that new: some of the foundations that underlie today's work were laid in the late 1940s and early 1950s by Alan Turing, whose "imitation game" (to- day called the 'Turing Test") is still considered a valid method for deter- mining whether or not a machine is intelligent. In essence, the Turing Test consists of an interrogator communi- cating via teleprinters with a human and a computer. The interrogator can attempt in any way possible to deter- mine which is which through conver- sation over the communication links. At first glance, it might seem that the examiner could easily tell the dif- ference by asking such questions as, "What is 35,289 divided by 91177" The human would presumably chew on it for a while, and the computer would instantly spit back an answer correct to twelve digits. The flaw in this kind of thinking is that the human might have an electronic cal- culator in his pocket and the com- puter, if indeed intelligent (and devious), might give a slow and er- roneous answer just to fool the inter- rogator. Also, the computer might be unable to calculate as rapidly as we would expect, since much of what we call intelligence involves the storage of information in a relatively abstract and very symbolic form. It is possible that such a machine would have to go through a set of thought processes not markedly different from ours to do mathematical calculations, though for the sake of convenience, it would probably have a built-in "calculator." Turing's work in this area was strangely prophetic and, for the con- servative 1950s, somewhat radical. He wrote, "I believe that at the end of the century the use of words and general educated opinion will have altered so much that one will be able to speak of machines thinking with- 170 September 1981 © BYTE Publications Inc Circle 344 on inquiry card. Finding the best software on the market can take you weeks. o Reading this ad takes 317 seconds and gives you the same results! The Westico Software Review Committee is easy to recognize. It's their red- rimmed eyes. You get that way checking through an endless parade of software programs. And they do it so that you don't have to. But selecting good software is only part of what makes Westico one of the fastest growing com- panies in the software industry. Having experts on staff who really understand both software and hardware isanother. But Westico offers more than auality products and TWO MORE GREAT PROGRAMS FROM WESTICO LYNX, a friendly overlay linker. LYNX Is an overlay linker for creating executable programs from relocatable files produced by Microsoft's FORTRAN, COBOL, and MACRO-80 languages. LYNX allows the construction of pro- grams that use all available memory including that used by LYNX Itself. Maxi- mum size programs under Microsoft's L80 linker can be increased at least 9K using LYNX without overlays. The overlay capability of LYNX is vital for programs largerthan available memory. With overlays, many large programs on minicomputers or large mainframe computers can be easily moved to a microcomputer. LYNX offers many features not found in L80. For example, LYNX can be tola to get commands from a disk file. The "HELP" feature displays a complete list of LYNX commands. Mapping informa- tion can be sentto the screen, printer or disk files. LYNX can decode Microsoft REL files for inspection. LYNX uses overlays in a tree structure. Any routine is available to any overlay that is higher on the branch than the routine itself. Complete system with documentation S250. Documentation alone 525. Now il makes sense to MINCE words. MINCE is a full screen editor based on the "Emacs" text editor, developed after years of research in editor technology and user interface at M.I.T and other uni- versities. With MINCE you can edit several files simultaneously, allowing the text to be moved between the files. The screen can be divided to display any two files or two parts of the same file at one time. Text can be manipulated by the word, sentence or paragraph, as well as character, line ana entire screen with simple, easy-to-remember commands. MINCE automatically adjusts line length to margins as the text is entered. Com- mands change words to UPPERcase, lowerCASE or Capitalize. The MINCE uniaue "guery replace" allows global changes to be "tried-out" and then accepted or rejected. Lines can be cen- tered, "white space" removed and text then inserted or overwritten. MINCE is as powerful an editor for programmers as it is for creating documents. MINCE fea- tures "type ahead" and a status line which constantly displays: editing mode, the files being edited, the current posi- tion in the file, the file modification — if any, the state of the "save" buffer and the command currently being executed. Complete system with documentation — $175. Documentation alone — $25. support. We offer our unique 24-hour service overnight! Westico. We're working hard to be your software company. The Westico 24-Hour Computer Hotline (300 baud) (203) 853-0816 for detailed program information and quick access ordering. — A full range of professional software. — Support for a wide variety of CP/rVT and other computer systems, in- cluding: TRS-80 Model II, Apple, Vector Graphic, Cromemco, North Star, Micropolis, Ohio Scientific, Altos, Dynabyte, SuperBrain, Xerox, Zenith and more. I II 4 Ways to Order • Write Westico, Inc., 25 Norwalk, CT 06855. • Call (203) 853-6880. Telex 643-788. Dial-up our 24-hour computer (300 baud) (203) 853-0816. COD, MasterCard and VISA accepted. Prices do not include shipping and are subject to change. In CT add 7VS% sales tax. All sales final. Manual price may be credited toward Durchase of software. Dealer Inquiries invited. Copyright © 1981 Westico, Inc. WES-36 Send for FREE catalog. WESTICO The Software Express Service 25 Van Zant Street • Norwalk, Connecticut 06855 (203) 853-6880 • Telex 643-788 tPU'S & SUPPORT CHIPS I f MC58000L - S125.0O B085A AMD 2901 8212 - 2.90 - 3.25 MM5307 8226 8228 8251 8259 8257IAM9517)- Z8A CPU 280AS10 B275 - 9.95 C/MOS 6.75 12.95 16.95 RAM's ROM's 4116-3 4116-2 21L02-3 2102-4 MK40273 MK4096 11 TMS4045-25 MS4050NL 2101-1 2107675280 MM 5270 MK4008P IM7001 270a 2716 2716 . 5V 2732 82S23 82S112 825115 82S123 82S129 82S130 82S131 AM9218C 82S181 8256-6(7418 20 4027 - 74CC0 74C02 74C08 74C10 UART's - 3.75 - 3.95 - 3.25 AY3-87O0 INTERFACE & DRIVERS 8833 - 2.50 8834 - 2.00 8837 - 2.00 - 2.00 8T380 - 2.00 COM2057 - 3.75 AY3-8500 - 1.95 - 2.25 SHIFT REGISTERS MM 1402 1.75 MM 1403 - 1.75 MM1404 - 1.75 MM5013 MM5016 MM5055 MM5056 MM5057 MM5058 MM5060 2.50 2.50 2.60 250 14 PIN HEADERS 3/$1.00 16 PIN HEADERS 40 24 PIN HEADERS 75 40 PIN HEADERS 1.10 50 PIN EDGEBOARD CONN 3.95 26 PIN EDGEBOARD CONN 2.50 50 PIN RIGHT ANGLE CONN 3.95 20 PIN RIGHT ANGLE CONN 2.25 SPECIALS 4ea. 2716 ( + 5V) 28.00 8ea. 4116-3 RAM'S 18.95 10ea. 8164E64K RAM (150NSI .99.50 L14H4IR+VISIBLE DETECTOR .3/41.00 MM5307 — Baud Rate Generator . .$9.95 50 PIN RIBBON CONNECTORS ....3.95 40 PIN RIBBON CABLE CONN 3.25 20 PIN RIBBON CABLE CONN 2.65 10 PIN RIBBON CABLE CONN 1.75 LM380 1.25 RS 232 CABLE 10 Conductor, ft 22 color coded wire, gray PVC outer cover, %" diameter .40 per ft. - 100 7$30.00 Add 20% postage for orders under 100'. Add 10% postage for orders over 100'. SPECIALS GOOD THRU SEPT. 1981 CRYSTALS $3.45 ea. 1/16" thick with 1/10" spacing 4%"x 6Y2" $1.95 DATEL'S DAC-08EQ 8 bit DAC - $7.95 INTERSIL DG1IBP ANALOG SWITCH/ 2 CHANNEL DRIVERS $11.50 INTERSIL ICL 7104-12 CPL 12 BIT AID CONVERTER $26.50 REOICON SAD 1024 ANALOG SWITCH $10.95 74600 74S03 74S04 74505 74S08 74S10 74S11 74S1B 74S20 74S30 74S32 74S74 .70 Afl .60 1 1.30 7 W .B5 r t:« m 1.50 7: r« 1.26 7 v« 1.10 7 14(1 1.00 . 7. ivt 1 10 7. I'll 1.26 7. lb/ 1 25 '4S174 '4S17S '4S134 '4S2&7 7 WATT LD 65 LASER DIODE IR $8.95 25 watt Infra Red Pulse (SG 2006 equiv.) Laser Diode (Spec sheet included)! $24.95 2N3820PFET $ .45 2N5457NFET $ .45 2N2646UJT $ .45 ER 900 TRIGGER DIODES 4/S1.00 2N 6028 PROG. UJT $ .65 DISC CAPACITORS .1UF16V 10/S1.O0 ioo/$a.oo .01UF35V 16/51.00 100/S5.00 IN4148 0N914) 15/1.00 6.144 MHz 8.000MHz 10.000 MHz 18.000 MHz 18.432 MHz | 20.000 MHz WE SHIP OVER 95% OFOURORDERS WITHIN 24 HOURS OF RECEIPT MINIATURE MULTI-TURN TRIM POTS 50, 100, 5K, 10K, 250K $.75 each 3/$2.00 NO. 30 WIRE WRAP WIRE SINGLE STRAND 100' S1.40 ALCO MINIATURE TOGGLE SWITCHES MTA106DSPDT $1.20 MTA206DPDT $1.70 MSD 206 P-DPDT CENTER OFF LEVER SWITCH .$1.85 SCR's 1.5A BA 35A 110A too .45 .60 1.40 200 .70 .80 1.90 9.00 400 1.20 1.40 7.m 12.00 600 1.80 3.60 15.00 TRIAC's PRV 1A 10A 25A 100 .45 .80 1.55 200 .84 1.30 2.10 400 1.30 1.90 3.10 600 2.00 2.75 4.30 FP 100 PHOTO TRANS S .50 RED. YELLOW, GREEN or AMBEP. LARGE LED's 2~ .6/51.00 RED/GREEN HIPOLAR LED's S 55 MLED92 IR LED S 75 MRD14B PHOTO DARL. XTOR S 50 TIL-tlBOPTO-ISOLATOR S .45 IL-5 0PTO-ISOLATOR $ 45 1 WATT ZENERS: 3.3, 4.7. 5 .1, 5.6,6 8, 8 2, 9 1. 10. 12. 15. 18.or22V 6/SI 00 SFC 3301 - 50 PRV 30A FAST RECOVERY DIODE (35ns) ..$2.25 TANTALUM CAPACITORS .47UF35V 5/S1.00 .68UF35V 5/S1.00 1UF35V 5/S1.00 2.2UF20V 5/51.00 3.3UF20V 4/41.00 4.7UF35V 4/$1.00 6.8UF35V 3/S1.00 10UF35V 22UF 10V 15UF16V 30UF6V 33UF 20V 47UF20V 120UF6V -S .40 -$ .30 3/$1.00 5/S1.00 PRV 1A 3A 12A S0A 125A 240A 100 .06 .14 .35 .90 4.25 6.00 200 .07 .20 .40 1.30 5.25 9.00 400 .09 .25 .65 1.50 6.50 12.00 600 .11 .30 .80 2.00 8.50 15.00 800 .15 .35 1.00 2.50 10.50 18.00 TRANSISTOR SPECIALS ALS ^ 74C74 60 74C76 .70 74CB3 1 30 7JC85 1,40 74C90 90 .95 1 75 ..75 74C160 1.20 74C161 1.15 74C163 l.tB 1.25 74CI73 1.30 74 C 17.1 74C175 1 20 74C192 1.30 74C901 50 74C926 550 :'N1.]HJ,'NF'GET05 ::N.:(M.M'N'PC5£TO-5 HEPG6014 PNPGETO-3 iuw.q Npfjfiwirctii'japov.'Ff Mur ii:-;;;,. Cii r< : t^.v.s^toh '. /fO'7?r.PNSiTO-3 ;'N.inoHPMP5iTO-3 ;rij3i37iiF'NSiHF 2N2907PNPSi 2N3055NPrjSi 2N39Q4NPN5I 2rJ3905PNPS> 2N5296NPN "' TIP31BNPNSi TO-92 TO -220 TO220 TO220 TO220 7402 7403 7404 7405 740S 7407 7408 7409 7410 7417 7420 7425 7426 7427 7430 7432 7437 7438 7440 7441 7442 7445 7446 7447 7448 7450 7472 TTLIC 7473 7490 - 7491 7492 7493 7494 7495 7496 - 74107 - 74121 - 74122 - 74123 74125 74126 74145 74150 - 1 74151 74153 75154 - 1 74155 - 74157 - 74160 - 74161 - 74162 SERIES 15 74165 74170 74173 - 74174 - 74175 - 74176 74177 - 74180 74181 - 74182 - 74190 74191 74192 - 74193 74194 - 74195 - 74196 - 74197 74279 - 74365 - 74367 - 74368 .6 74390 9 75324 - 2.2 74325 - 1.5 75491 - 1.0 75492 - 1.0 8T98- 1.; 9312 - ,6 FULL WAVE BRIDGE i.90 t.40 DIP SOCKETS SPIN .17 22PIN .30 14 PIN .20 24 PIN .35 16 PIN .22 28 PIN .40 18 PIN .25 40 PIN ,60 74LS SERIES 74LSOO 741 S01 74LS02 74LS03 74LS04 741S05 74 L 508 74LS93 74LS96 - 74LSI09 74LS18 .65 20KV250MA DIODE $1 .90 SILICON POWER RECTIFIERS 74L537 74LS38 74LS40 74LS42 74LS73 74LS74 74LS75 74LS76 74LSB3 74LSB6 74LSHG 74LS02 74LS1E-! - 74LS16B - 74LS169 74LS170 - 74LS173 - 74LS174- 74LS176 - 74L5181 - 74LS190 - 74LS191 - 74LS192 - 74LS193 - 74LS197 - .85 74LS221 .80 74LS240 - .05 74LS241 - .95 74LS242 .95 74LS243 - 1.00 74LS244- 1.35 1.50 74LS247 74LS248 - 1 74LS25I - 74LS253 - 74LS257 - 74LS25B 74LS259 1. 74LS266 - 74LS273 - 1 74LS279 - 74LS280 - 1 74LS283 - 74LS290 74LS293 - 74LS365 - 74LS366 - 74LS367 74LS368 74LS373 - 1 74LS374 1 74LS377 - 1 74LS386 - 74LS390 - 1 74LS393 - 1 74LS670 - 2 81LS97 - 1 LINEAR CIRCUITS out expecting to be contradicted." Once again, technological progress is ahead of schedule — maybe. One of the distinguishing and provocative features of AI is that newer and ever more complex problems lurk behind each breakthrough. Most technol- ogies reach maturity when progress becomes asymptotic: continued effort brings us closer and closer to the limits of what is possible but at an ever slower rate. (An example of this is the ongoing effort to make elec- tronic logic devices switch faster. The time it takes for electrons to move from one place to another defines an immutable speed limit, and future performance increases must come from another source.) AI doesn't seem to have such a limit, or if it does, it is (by definition) even further removed from our present compre- hension than a complete picture of how the brain works. This limitlessness makes AI, for many people, the most enchanting field of endeavor in the vast panoply of research fields. In the thirty years since Turing wrote his prophetic words, AI has grown from an esoteric part-time pursuit of a few visionaries to a full-fledged science, replete with subspecialties, societies, annual inter- national conferences, and journals. Its existence is beginning to be felt outside academia, and in a few years, the computer as we know it is likely to be dramatically transformed. Work in Progress There are a number of robust sub- specialties in the world of artificial in- telligence, dealing not only with various applications but with several problems that must be simultaneous- ly overcome for the dreams of Turing and many others to be fullfilled. The two central problems are so closely intertwined that they can be discussed together: knowledge representation and natural language. Consider the following conversa- tion: He: "Hungry?" She: "I have a coupon for McDonald's." He: "Have you seen my keys?" She: "Look on the dresser." 172 September 1981 © BYTE Publications Inc IF YOU CAN RECOGNIZE VALUE YOU CAN SAVE $500°o INTRODUCTORY OFFER M.T.I. MOD III Now You Can Save $500 over comparable model M996 We hove token the basic 16K Model III expanded the memory ro 48K and added our MTl Double Density, Dual Disk Drive system. System is fully compatible with Radio Shack DOS and peripherals. MOD HI/EXPANDED Same as above but has double storage capacity (708K storage). Your choice of 2 dual headed 40 track drives or 2 single headed 80 track disk drives. - Includes Microsystems DOS plus 3.3 *2499 MOD 1 1 1/280 Our largest MOD III, approximately 1 .5 mega bytes of storage, utilizes 2 dual headed 80 track, double density disk drives. Complete with manuals and professional operating system, Microsystems DOS plus 3.3 (40 6- 80 track capability). >2799 MTl has a complete line of COMPUTER odd ons: INTERNAL DISK KIT 40 OR 80 TRACK EXTERNAL DISK KIT 40 OR 80 TRACK Drive Kit #1 from '699 Drive Kit #3 from s 379 TRS DOS b Manual s 21 .95 Drive Kir #2 from s 279 Drive Kir #4 from l 359 DOS PLUS from '99 MTl MOD III SALES, PARTS 6 SERVICE CENTERS - INDEPENDENT DEALERS WASHINGTON (509) 504-3955 SAN JOSE (408) 946-1265 SANTA CRUZ (408) 427-0636 SAN DIEGO (714)281-0285 HAWAII (806) 261-4042 TEMPE, AZ (602)839-0546 PHOENIX, AZ (602) 244-9739 TUCSON. AZ (602) 323-939 1 SIERRA VISTA. AZ (602) 458-2479 TEXAS (214) 247-6679 N G S DAKOTA (701 ) 594-5674 MIDWEST (616) 345-5068 CLEVELAND, OHIO (216)779-6040 MAUMEE. OHIO (419) 893-4288 GEORGIA (404)449-8982 FLORIDA (305)981-9091 WHITE PLAINS, N.Y (914) 948-7980 ASTORIA, N.Y (212) 728-5252 TROY, N.Y (518) 273-8411 REP. OF SOUTH AFRICA ... 021-45-1047 AUSTRALIA 03-877-6946 S\A MICROCOMPUTER TECHNOLOGY INC. 3304 W. MACAPTHUR, SANTA ANA, CA 92704 • (714)979-9923 • TELEX 6780401 TABIPJN • "Uses MTl Memory. Disk Drives G Components. US. PRICES F.O.B. SANTA ANA, CALIFORNIA Circle 229 on Inquiry card. BYTE September 1981 173 There are some very sophisticated information-processing operations going on here. In this dialogue, most of the real meaning — the real com- munication — is not explicitly stated. He opens by inquiring whether she is hungry and, in the process, is prob- ably implying that he is hungry as well. She processes this and issues a very cryptic response. Not only does she inform him that she is either hungry or willing to go along for a ride, but also suggests a specific place to eat and, further, hints at economic realities by weighting the selection of a restaurant on the basis of a discount coupon. Her statement assumes that he will understand what a coupon is as well as what a McDonald's is. His next question indicates even deeper communication: he has agreed with her about the choice of restaurant and suggests a specific mode of transpor- tation. This suggestion, however, is made in a roundabout fashion: he asks if she knows where his keys are at the moment, assuming that she knows not only what keys are but that they are linked with transporta- tion. She, of course, understands that the keys he's talking about are those of his automobile and suggests a course of action that will solve the transportation problem — correctly assuming that he will not only know which dresser she means, and that a dresser is a piece of furniture, but that he will deduce that the keys must be there. The implication is that communica- tion between two people involves substantially more than the lexical meanings of the words. The conver- sation above would not have been so succinct if he had approached a stranger on the street with the same question. The difference suggests the existence of a special relationship be- tween he and she: they share certain aspects of their internal models of the world. This highlights a crucial truth: lan- guage has to be considered as only one part of a much more complex communication process, one in which the knowledge and states of mind of the participants are as much responsi- ble for the interpretation of verbal ut- terances as are the words from which those utterances are formed. As a conversation progresses, the internal state of each participant continually changes to represent the modified reality that is the result of the com- munication. (Frequently, problems occur be- tween people when their respective internal models of the world differ sharply. "I had to work late," can be interpreted in a drastically different way from that intended by the speaker.) When one attempts to build an in- telligent machine, the complexities in- troduced by this larger view of com- munication can be surprising. Early systems were developed without a clear awareness of the problem and were constructed of a stored body of facts with associated keywords that were used (eg: Joseph Weizenbaum's ELIZA program) to scan the input messages. Whenever there was a match, sets of specific rules were in- voked to produce a response based on both the system's knowledge and the keywords it had located. No atten- tion was given to the actual meaning of the sentences, just to the presence of certain words. Such systems quick- ly fail the Turing test. As time went on, it was recognized that the communication problem is interwoven with knowledge itself. In the mid-1960s, programs were devel- oped to translate input sentences into an internal formal language that, theoretically, would allow the system to perform inferences without need- ing to handle all the subtleties of or- dinary conversation. But the knowl- edge and the meanings of words were still represented as passive data "ob- jects" distinct from the program itself. Thus, it was difficult for any but the most rudimentary changes to occur in the system's internal model of the world. Recently, a different approach has begun to show promise. Instead of clear differentiation between the "in- telligent program" and the knowl- edge, the programs actually embody the knowledge in their structure. With the existence of powerful AI languages (such as LISP), it is possible for the system to learn and grow by modifying itself. VISIT THE /MicroAge STORE IN YOUR AREA! 9530 Viscount 1 490 W. Spring Val ley Rd. El Paso, Texas Richardson, Texas (915) 591-3349 (214) 234-5955 611 Rockville Pike 83 South 10th Street Rockville, Maryland Minneapolis, Minnesota (301)762-7585 (612)338-1777 5742 E. Broadway 24 W. Camelback Tucson, Arizona Phoenix, Arizona (602) 790-8959 (602) 265-0065 2760-S South Havana 2591 Hamilton Rd. Aurora, Colorado Columbus, Ohio (303) 696-6950 (614) 868-1550 1707 Monroe Avenue 8615AllisonvilleRd. Rochester, New York Indianapolis, Indiana (716)244-9000 (317)849-5161 1220 Melbourne Drive 1517 N.E. 122nd Avenue Hurst, Texas Portland, Oregon (817)284-3413 (503)256-4713 2675 Mayfair Road 79 Main Street Milwaukee, Wisconsin Norwalk, Connecticut (414)257-1100 (203)846-0851 2065 El Camino Real West 11413 Olive Street Road Mountain View, California St. Louis, Missouri (415) 964-7063 (314) 567-7644 2525 N. Scottsdale Road 581 5 Menaul N.E. Scottsdale, Arizona Albuquerque, New Mexicc (602) 941-8794 COMING SOON TO: San Diego, California Spokane, Washington Toronto, Canada Boston, Mass. Pompano Beach, Florida Palm Beach, Florida Houston, Texas Wilmington, Delaware Panama City, Panama Salina, Kansas Anchorage, Alaska Walnut Creek, California Tinley Park, Illinois Oklahoma City, Oklahoma Chicago, Illinois Washington, DC FOR FRANCHISE OPPORTUNITY INFORMATION CALL (602) 968-3168 174 September 1981 © BYTE Publications Inc CASHFLOW PROBLEMS? ( irS NICE TO KNOW SOMEONE WHO HAS THE SOLUTION. MicroAge is your Solution Store . . . that means at MicroAge Computer Stores we have a wide selection of time-saving computer- ized business systems designed specifically to solve the daily cash flow problems every business- man faces. MicroAge has computer- ized business systems that quickly and affordably allow you to regain con- trol of your critical accounts receivable ... at last making it possible for you to carry out effective collection procedures on a consistent basis. MicroAge has accounts receivable program packages to automatically display and update account information; prepare trial balance including a balance-due and delinquency aging Circle 214 on Inquiry card. report, and take care of dozens of other tasks that eat into your time and profit! Computerized business systems from the Micro- Age Computer Store are available in the $5,000 to $15,000 range, to suit the individual budget of your small business or professional practice. MicroAge backs up every system with personal- ized service, warranty service and repair, instal- lation, systems consulting, even customer train- ing. Visit the MicroAge Computer Store in your area soon with your business problems, and let us help you with the solution. MkxoAqo caupuTer sTore "The Solution Store" SM Snf'sVMS HunS uMJI W This all sounds very anthropomor- phic, but there is still a vast gulf be- tween our minds and even the best of the artificially intelligent systems. Though we have the technology to provide an equivalent amount of raw data storage, we may be going about it all wrong. Serial Versus Parallel There are numerous computational feats that humans manage to accom- plish daily without conscious effort. Many of them are still impossible for computers. Take pattern recognition, for example. When a friend walks in- to the room, you can establish his or her identity with a casual glance. The accuracy of your decision is not markedly affected by the set of the jaw, the tilt of the head, or disheveled hair. According to current theories, you simply map a preprocessed visual image via some feature-extraction "hardware" onto a gigantic multidi- mensional associative memory. The answer pops out, linked with an elaborate internal model of your friend. Big deal. A computer, on the other hand, has quite a chore to perform when it is fitted with a television camera and directed to recognize a face. It must scan the image raster dot by dot to acquire a numeric representation in memory. Then, it must engage in fast and furious number-crunching to cal- culate the spatial Fourier transform of the face. Elapsed time at this point might be pushing a minute or more, and the machine still hasn't the fog- giest notion of who it's looking at. Then comes the hard part: one by one, the system must perform two-di- mensional correlations between its freshly calculated data and blocks of stored image data corresponding to the people it "knows" — in each case, coming up with a number (the corre- lation coefficient) between and 1 that expresses how much like a stored image the current image is. The stored image with the highest coeffi- cient is deemed to be the one that matches. But, if the person in front of the camera parts his hair differently, cocks his head to one side, and takes on a dramatic expression, then he might as well have just become some- one else. This problem gives specialists in image recognition fits. If a computer's logic devices can switch as much as a million times faster than human neurons, it would seem that even in- tensive tasks such as pattern recogni- tion could be done with correspond- ingly greater speed, even if not with ease. Not so. Here's the catch, and its solution will probably represent the next major revolution in computer design: Brains don't center around single devices called "processors." Computers do. Operations that the brain seems to perform with the simultaneous activation of millions of widely distributed logic elements must be performed in a computer by funneling the entire task through one tiny bottleneck. In many cases, the blinding speed of computer hardware more than makes up for this handicap (in calculating, sorting, etc) but in the types of problems encountered in the "I have recently used Spellguard and I can only echo the eval- uations of a recent Infoworld review: excellent all the way." Mark Garetz Infoworld 25 May 1981 "Spellguard is an example of the new standard— fully pro- fessional microcomputer software." Bill Burns Infoworld 30 March 1981 " . . . Spellguard was given the manuscript from my first book. This version had been corrected after several (human) proofreaders thoroughly reviewed it. I therefore expected it to be relatively error free. Not so. Spellguard was EXPERTS AGREE SPELLGUARD IS THE FASTEST EASIEST TO USE MOST POWERFUL AND RELIABLE SPELLING CHECKER YOU CAN BUY able to discover numerous typographical errors . . ." Allan Miller Interface Age June 1981 "This easy to use, operator-oriented program has saved me countless hours of proofreading, and from the embarrassment of submitting a manuscript with typos. Unlike most spelling test programs, Spellguard is fast . . ." Tony Dowden Microcomputing May 1981 InfoWotld Software Report Card O/JELLGUARD I'sefulnesN Documentation Ease of I '»e Error Handling S A 1 1 I fi 3 I DDDSf □ □ □ W □ □ D H' aaasr System Requirements • CP/M (1.4 or later) • 32 K bytes of memory • One or two disk drives Price: $295 INNOVATIVE SOFTWARE APPLICATIONS 260 Shendon Avenue Suite 300 Palo Alto. CA 94306 P O Box 2797 Menlo Park. CA 94025 (415) 326-0805 176 September 1981 © BYTE Publications Inc Circle 168 on inquiry card. SUPERBRAIN QD VS. SUPERBRAIN the two top microcomputer contenders When you decide to buy a microcomputer system, it usually gets down to one model versus another. Will it be the SuperBrain from Intertec ... or one of those other models from Intertec's competitors? Well, there's really not much of a choice in the price/performance competition. The SuperBrain wins hands down! And it's a pretty tough contender if reliability, factory support and nationwide service are important to you. So what do you do? Choose our SuperBrain just because you know it's best? Or keep waiting for someone to announce some- thing better? WAIT NO LONGER... It wasn't enough that our SuperBrain had such standard features as twin double-density disk drives with nearly 350,000 bytes of disk storage. A full 64K of dynamic RAM. A CP/FvT Disk Operating System which assures compatibility to literally hundreds of application packages. A crisp, 12" non- glare screen with a full 24 line by 80 column display. A full-featured ASCII keyboard with a separate keypad and individual cursor control keys. Twin RS232 serial ports for fast and easy connection to a modem or a printer. Plus, dual Z80 processors which operate at 4 megahertz to insure lightning- fast program execution. No, it wasn't enough, So we changed it. We made it even better! ANNOUNCING SUPERBRAIN QD... Our new QD model boasts all the features of our phenomenally popular SuperBrain with the addition of double-sided disk drives. So, for only a modest increase in price, you can order your next SuperBrain with more than twice the disk storage. But, best of all, you can field upgrade the disk capacity of either model to a whopping 10 megabytes! Now how's that for a choice? HOW DID WE DO IT? The secret of SuperBrain QD's incredible disk storage lies within our new double-density, double- sided disk drives. Nearly 750,000 bytes of data can be formatted on two specially designed W drives. More than enough to tackle almost any serious small business application. Plus, SuperBrain QD's 64K of dynamic RAM will handle even your most complicated programming tasks. 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The CompuStar™ Disk Storage System . . . Connects in seconds to either model. THE DECISION IS YOURS... Whether your next microcomputer is the Super- Brain or our QD model, you'll be purchasing what is becoming one of the world's most popular micro- computer systems. And regardless of which model you choose, you'll probably never outgrow it because you can keep expanding it. Call or write us today for more information on our full line of microcomputer systems. Ask for our "SuperBrain Buyer's Guide" and read why so many customers like yourself have made the SuperBrain and the SuperBrain QD their top two choices for performance, value and reliability. Circle 175 on Inquiry card. 3 r= INTRTEC Edata s systems. 2300 Broad River Rd „ Columbia, S.C.. 29210 (803) 798-9100 TWX' 810-666-2115 •Registered trademark ot Digital Research Inc attempt to create something called "intelligence," it hasn't a prayer. The solution is not exactly trivial, and it must wait for device tech- nology, neurophysiology, and sys- tems theory to provide a few more links. But our hands are by no means tied: the work currently being done in knowledge representation, natural language, cognition, vision, and countless other specialties will con- tinue to provide mankind with better and better tools for the manipulation of information. When brainlike sys- tems make their debut, they will have a rich AI technology to draw upon. Intelligence Amplifiers Through all this, there has been lit- tle space for an explicit discussion of applications. Rather than attempt to catalog all of the present and poten- tial uses for intelligent machines (a task that should be relegated to an in- telligent machine), let's round out this overview of the field with a general image of their value to our species in general. It is colorful to think of computers as intelligence amplifiers, analogous to the amplifiers of various sorts with which we enhance the power of our voices, muscles, and senses. Now we can enhance the power of our minds. Computers are magnificent tools but not yet true Intelligence amplifiers. It's already happening, of course, with home-computer systems cheaper in many cases than the color-televi- sion receivers that serve as their dis- plays. But the vast computational gulf that exists between brains and computers has kept the devices some- what distant from their human owners. Magnificent tools, in- deed — this article was written on a home word-processing system — but intelligence amplifiers? My brain has as little in common with this com- puter as it does with a pocket calculator. It's not the computer's fault, really; even with its pathetic handicap of a single processing site, it has enough power to be of considerable use. But, as I pointed out earlier, it's dumb. Its internal model of the world is sorely limited and alien to me. Communica- tion with it is formal and restricted and must occur only within the syn- tactic restrictions of its programming languages. I cannot err slightly in an instruction and be understood; I can- not express my thoughts to it in analogies or abstractions. Even if I know exactly what I want it to do, I have to work very hard to tell it precisely how. In some cases, I can do the job better and faster myself. None of this is intended to denig- rate the value of computers, but it should underscore the value of AI. 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Ventura Blvd. (213) 704-6895 In Torrance/Lawndale 16206 Hawthorne Blvd. (213) 370-1577 fm |l /VIICRO BUSINESS WORLD rl il MAnL@fRifO)E[Ri SMBST. : MICKO TZNA Oly Make State Model Zip nem One, M IOI M ORDER* IAX IF APPLICABLE' SHPPING& HANDLING" CREDIT CARDS ADD 3".= - TOTAL ENCLOSED S I Mti . -i \l I VS MAXELL • DYSAN • EPSON • CCS • SHARP • CASIO • HP • VERBATIM • MEMOREX • SOROC • CORVUS • PERSONAL SOFTWARE • ADDS Circle 216 on inquiry card. A High-Level Language Benchmark Jim Gilbreath 7266 Courtney Dr San Diego CA 92111 Some computer languages are faster than others, but just how much faster? This article presents the data from a curiosity-driven project that compares the performance of nu- merous high-level languages on the small computers to which I had ac- cess. The benchmark tends to focus on the language characteristics that most interest me: capabilities and efficien- cies for systems programming, soft- ware tools, and data manipulation (such as takes place in sorting, graphics, and games). I wanted to measure the ability of a language to do memory references, structured control statements, and simple in- put/output operations. I did not want to measure integer and real-number arithmetic performance because that depends on the processor and its capabilities (eg: precision of numeric calculations, the presence or absence of hardware multiply and divide cir- cuits, and so on). Acknowledgments Grateful thanks are extended to members of the San Diego Computer Society and the S-100 Innovators Special Interest Group, for allow- ing me access to their systems and languages. Special thanks to Frank MacLachlan, Pete Ridley, and Mike Lehman for their encourage- ment and help. Criteria My criteria were that the bench- mark should be short (not more than a page of source code), able to access a considerable amount of memory, devoid of multiplication or division performance, and easily coded in a variety of high-level languages. Final- ly, the benchmark should accomplish something useful (or at least recog- nizable and verifiable). This benchmark is not the only criterion by which to judge a language or compiler. At the January 1980 UNIX confer- ence in Boulder, Chuck Forsberg told me about a program that used the Sieve of Eratosthenes algorithm (see references) to compute all prime numbers from 3 to 16,000. Unlike other methods, the Sieve avoids divi- sion and is extremely fast because it uses prior knowledge about numbers that cannot be prime (ie: even numbers and multiples of primes). I modified Knuth's program to elim- inate all multiplication, scaled it to fit most microcomputer memory capa- cities, and translated the program to every accessible high-level language. I should emphasize that this bench- mark is not the only criterion by which to judge a language or com- piler. It doesn't explore or exploit such language features as recursion or sets, which may be very important for some applications. It does com- pare code generation and run times for fundamental language features, which are important for data access- ing and structured program looping. The Program The program for each language was coded conventionally, taking ad- vantage of features that are defined in the language, but not exploiting the clever or obscure innovations that can make it run faster. In most cases, some improvement in running time could be achieved by knowledgeable trickery. [In fact, that is the point of a benchmark program: to compare lan- guage performance by running the same algorithm encoded in different languages... GW] The program is small and simple, and, in most cases, easy to transfer. A few of the transla- About the Author Jim Gilbreath is the head of the Computer Sciences and Simulation Department at the Naval Ocean Systems Center. He has 23 years of experience in both hardware and software technology. 180 September 1981 © BYTE Publications Inc INTROD URITER BY MP I Fontwriter is the newest addition to the growing fam- ily of MPI Printer products. Itenablesyou to print BIG, GRAPHIC fonts on MPI Printers just as easily as others print standard characters. Your local Apple dealer has been sent a demonstration diskette that describes Fontwriter and all the other capabilities of MPI Printer Systems. Ask to see the disk and a powerful MPI printer at work. And remember, MPI printers, complete with dot addressable graphics, cost less than the low cost imported job that has been getting all the attention lately. MPI Printers are clearly the best printer buys in the US. Apple is a trademark of Apple Computer Inc. Ampi Micro Peripherals Inc. 4426 South Century Drive Salt Lake City. Utah 84107 (801) 263-3081 The Printer People Circle 248 on inquiry card. BYTE September 1981 181 tions required more time because of the lack of control structures and my GOTO blunders. FORTRAN, FORTH, and COBOL (in order of in- creasing difficulty) gave me the most trouble. Program listings in the ten most in- teresting languages appear in listings 1 thru 10. You might want to try a few on your favorite compilers. Listing 1 shows the program in ZSPL, a structured high-level Ian- Listing Is Implementation of the Sieve prime number program, written in ZSPL. * Eratosthenes Sieve Prime Number Program in ZSPL ident zprime; external function aryset; external function exit; external function printf; define true := 1; define false := 0; define size := 8190; define sizepl := 8191; byte array flags [sizepl] ; integer count; integer i; integer iter; integer k; integer prime; printf (-1, "10 iterations&M&J" ) ; for iter := 1 to 10; count := 0; aryset (true, flags, size) ; for i := to size; if flags[i) = true; prime := i + i + 3 ; k := i + prime; while k <= size; flags[k] := false; k := k + prime; endwhile ; * debug aid * pr intf (-1, "%d&M&J" , prime) ; count := count + 1; endif ; endfor ; endfor ; pr intf (-1, "%d pr imes" , count) ; exit () ; end; name of module sets array elements returns to cp/m types things largest index total array size array of flags no. of primes found array index counts number of passes index to non-primes holds prime number type starting message do whole thing ten times zero prime counter set array to true go thru whole array we have a prime value of prime index to multiple loop to kill multiples set non-primes to false next non-prime type value of prime count primes found type no. primes found return to cp/m Listing 2: Implementation of the Sieve program, written in Pascal. (* Eratosthenes Sieve Prime Number Program in PASCAL *) PROGRAM PRIME; CONST SIZE = 8190; VAR FLAGS : ARRAY [0..SIZE] OF BOOLEAN; I, PRIME, K, COUNT, ITER : INTEGER; BEGIN WRITELN('10 iterations'); FOR ITER := 1 TO 10 DO BEGIN COUNT := 0; FILLCHAR(FLAGS,SIZEOF(FLAGS) ,CHR(TRUE) ) ; FOR I := TO SIZE DO IF FLAGS [I] THEN BEGIN PRIME := I+I+3; K := I + PRIME; WHILE K <= SIZE DO BEGIN FLAGS [K] := FALSE; K := K + PRIME END; COUNT := COUNT + 1 (* WRITELN (PRIME) *) END; END; WRITELN (count,' primes') END. guage that is tailored to systems pro- gramming. ZSPL is chosen as the first example because you have probably not seen it before and because it is easy to read and understand. Begin by initializing an array of 8 kilobytes ("flags") to true. Flags(O), flags(l), flags(2),... represent the numbers 3, 5, 7, ...as numbers being tested for primeness. (See table 1.) The program uses the prior knowl- edge that 0, 1, 2, and 3 are the first four prime numbers, that all other even numbers are not prime, and that all multiples of prime numbers are not prime, to iterate through an array of flags, calculating primes as the value of variable PRIME (always 3 plus twice the current array index, I). As the program progresses, it also sets other values that cannot lead to a prime to false. When the program was timed, the second "printf" statement was made a comment and, thus, effectively removed. It remains in listing 1 so that you can see where to print the value of each prime number during debugging. For timing purposes, the program is executed (iterated) ten times. A Prime Number Representative Index Flags (Index) by Index TRUE 3 1 TRUE 5 2 TRUE 7 3 FALSE 9 4 TRUE 11 5 TRUE 13 6 FALSE 15 Table 1 : Values in array FLAGS after first iteration (1 = 0). Tht ' primeness of 3, which is the potential lumber corre- sponding to FLAGS(O), has just been determined. Note that a 1 multiples of 3 have been ruled out as potential primes: odd multiples (9 , 15,...) have had their corresponding FLAG entries (FLAG(3), FLAG(6),...) set to "false"; even multiples (6, 12,...) have already been ruled out. 182 September 1981 © BYTE Publications Inc Circle 7 on inquiry card. AND STILL THE LEADING EDGE . . . IN SYSTEM PERFORMANCE tBwssSStft Hard Disk and Streaming Tape reliability and versatility that can't be beat T OEM CONTROLLERS ROES 1 31 or 62 MByte formatted • 10.5 or 32 MByte formatted • Lowest cost/MByte from any manufacturer • CP/M* compatible "drop in" BIOS • Single S100 card controller -i Fully expandable up to four drives, 8" or 14" 1 Reliable high performance Priam Winchester Disks 1 Immediate delivery RDES SYSTEM 8 I" Winchester 10 or 32 MByte formatted Integrated streaming cartridge backup Streaming backup at 5 MB/min Selective file backup under CP/M Versatile parallel I/O or DMA interface •CP/M is a trademark ol Digilal Research Corp. 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Our Ann Arbor retail store is open 11:00 a.m. to 700 p.m. Tues-Fri. 1QOO a.m. to 500 p.m. on Saturdays . do i = 0,size { if(flags(i)) { prime = i+i + 3 k = i + prime while (k<=size) ( flags(k) = .false, k = k + prime } count=count+l } call putdec (count) ; call msgC primes.') end Listing 5, 6, and 7 are on page 188 186 September 1961 © BYTE Publications Inc Put Time and BSR/X-10 Control in Your APPLE II THUNDERCLOCK PLUS™ The THUNDERCLOCK PLUS is two peripheral systems on one card for your APPLE II, II PLUS, or III. An accurate, reliable, real-time clock/calendar and an interface for the popular BSR X-10 Home Control System. The THUNDERCLOCK clock/calendar makes accurate time and date available to your programs: month, date, day-of-week, hour, minute, and second, in any of four software selectable formats. On-board batteries keep your THUNDERCLOCK running when your APPLE II is turned off - for up to four years before battery replacement. On-card IK firmware makes reading or setting the time easy from APPLESOFT or INTEGER BASIC, PASCAL, or assembly language programs. And it provides software selectable interrupts at any of three rates: 64, 256, or 2048 interrupts/second. All features are software selectable - no switches or jumpers! THE PLUS Add THUNDERWARE'S X-10 ULTRASONIC INTERFACE OPTION to your THUNDERCLOCK and your programs can send all 22 BSR X-10 commands so you can remotely control lights and appliances. Plus a powerful disk software package! The THUNDERWARE SCHEDULER software lets you create schedules to control lights, appliances, security systems, or almost any other electrical device. The software includes: SCUTIL - the SCHEDULER utility that lets you make or change a schedule, and SCHED - executes your schedules in real-time using the THUNDERCLOCK. SCHED runs in the 'background' so you can run other programs in the 'foreground'. Our PASCAL software lets you use all the THUNDERCLOCK'S features and sets the filer date whenever you boot. The THUNDERCLOCK PLUS is a SYSTEM for your APPLE II. Supported by intelligent, easy to use firmware, a powerful software package, and good documentation! M Let the THUNDERCLOCK PLUS time/date stamp your DOS files whenever you create or modify them with our DOS-DATER software. The THUNDERCLOCK PLUS will work in any APPLE, including the APPLE III. See your APPLE dealer. Suggested retail prices: THUNDERCLOCK PLUS $139 Clock/calendar card with batteries and user's manual X-10 INTERFACE OPTION $49 BSR X-10 Ultrasonic interface, disk with SCHEDULER SOFTWARE & demos, and user's manual PASCAL SOFTWARE $29 Disk with PASCAL interface for clock and X-10 interface, and user's guide MANUALS ONLY, each $5 California residents add 6% sales tax If your dealer doesn't carry the THUNDERCLOCK PLUS: ORDER TOLL FREE (VISA/MC) CALL: 800-227-6204 Ext 307 (Outside California) 800-632-2131 Ext 307 (California Only) OR WRITE TO: THUNDERWARE INCORPORATED P.O. Box 13322, Oakland, CA 94661 Pascol So»»oro ... s ,. BSR X-10 is a trademark of BSR (USA) LTD. APPLE II is a trademark of APPLE COMPUTER, INC Circle 250 on inquiry card. MTI stocks 'en for faster deliv .all r ery. No hidden charges. Prices include c elivery. Ask about our" QED" discounts. VISA and MasterCard orders acce pted. 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NewYork: 516/482-3500,212/895-7177,518/449-5959 Outside N. Y.S.: 800/645-8016 New Jersey: 201/227-5552 i Ohio: 216/464-6688 J Listing 5: Implementation of the Sieve program, written in PL/l. /* Eratostnenes Prime Number Program in PLI-80 */ prime: proc options (main) ; %replace size by 8190, false by '0'b, true by 'l'b; del flags (0:8191) bit(l), (i, prime, k, count, iter) fixed; put list('10 iterations'); do iter = 1 to 10; count = 0; do i = to size; flags(i) = true; end; do i = to size; if flags(i) then do; prime = i + i + 3; k = i + prime; do while (k <= size) flags(k) = false; k = k + prime; end; count = count + 1; end; end; end; put skip list (count, 'primes' ) ; end prime; Listing 6: Implementation of the Sieve program, written in FORTRAN. C Eratosthenes Sieve Prime Number Program in FORTRAN LOGICAL FLAGS (8191) INTEGER I, PRIME, K, COUNT, ITER WRITE(1,50) 50 FORMAT (' 10 iterations') DO 92 ITER =1,10 COUNT=0 DO 10 I = 0,8190 10 FLAGS ( I) =. TRUE. DO 91 I = 0,8190 IF(FLAGS(I) .EQ. .FALSE. ) GOTO 91 PRIME=I+I+3 K=I+PRIME 20 IF(K.GT.8190) GOTO 90 FLAGS (K) = .FALSE. K=K+PRIME GOTO 20 90 COUNT=COUNT+l C WRITE(1,100) PRIME 91 CONTINUE 92 CONTINUE WRITE (1,200) COUNT 200 F0RMAT(1X,I6,' primes') STOP 100 FORMAT(lX,I6) END Listing 7: Implementation of the Sieve program, written in BASIC. REM Eratosthenes Sieve Prime Number Program in BASIC 1 SIZE = 8190 2 DIM FLAGS (8191) 3 PRINT "Only 1 iteration" 5 COUNT = 6 FOR I = TO SIZE 7 FLAGS (I) = 1 8 NEXT I 9 FOR I = TO SIZE 10 IF FLAGS (I) = THEN 18 11 PRIME = I+I + 3 12 K = I + PRIME 13 IF K > SIZE THEN 17 14 FLAGS (K) = 15 K = K + PRIME 16 GOTO 13 17 COUNT = COUNT + 1 18 NEXT I 19 PRINT COUNT," PRIMES" 188 September 1981 © BYTE Publications Inc FMS-8C I Organizes your Organization MS-80, a data base management system, offers the user a quick and easy way to organize and efficiently manipulate data so sound decisions i can be made on facts displayed. FMS-80 " is the ] most power- ful stand alone DBM program available to the micro- compute industry. Complet menu dr and writ in assem language it offers these features: • User definable File Definitions Screen Displays ,|Al Reports (with k) ; . math and field break analysis) Selection Criteria J (on any or all fields) Menus (that ap- plications programs can be selected from) • Instantaneous data query on indexed records. • Mathematical manipulation of numeric data fields using the report generator or the programming language EFM (Extended File Maintenance) • Easy to use video "how to" training tapes are available. • Manipulation of up to .19 differ- ent data files (using EFM) . , ? at one time and display*, ,: , ing this information on the screen, • rating reports, generating other data files or on- line updating of input files that already exist FMS-80 is able to call other programs like sub- routines in EFM o FMS-80 is able to read data files that other programs have generated No restrictions to record size other than avail- able RAM memory space Operates under CP/Mf MP/M a or CDOS°° FMS-80 allows the flexibility to quickly create programs that allow data to be entered in a : j form that ' ,.-A~~,i) $ a secretary ,1 recognizes and 'A "* generates reports that the manager requires. jf If you're continuously asked to do applications programs and don't have time to do it in BASIC, consider FMS-80. For additional information contact Systems Plus, 3975 East Bayshore, Palo Alto, CA 94303. Phone 415/969/7047 Systems Plus TMofDJRAs! nemco. Sunnvv ircll, Pacific Gn Circle 346 on inquiry card. BYTE September 1981 189 Circle 5 on inquiry card. SPECTACULAR OFFERS BASF "FLEXYDISK"... Superior Quality data storage medium. Certified and guaranteed 100% error free. SINGLE SIDED-SINGLE DENSITY 5Vi" or 8" Diskettes 1 0/$24 SVt" or 8" Vinyl Storage Pages 10/$5 MAXELL- DISKETTES The best quality diskette money can buy. Approved by Shugart and IBM. Sold only in boxes of 10 5", 1 side $3.30 8", 1-side $3.90 5", 2-side $4.25 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 SVi" Mini Kas - sette/10 $2.49 8" Kas-sette/10 $2.99 DISKETTE DRIVE HEAD CLEANING KITS , , j| Prevent head crashes and insure efficient, error- free operation. 5Va" or 8" $19.50 SFD CASSETTES C-10 Cassettes 10/ $7,fi^ (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 SVt" Applicator $3 8" Applicator $4 5Vt" Hardholes $6 50/8" Hardholes $8 VISA • MASTERCHARGE • MONEY ORDERS CERTIFIED CHECK • FOR PERSONAL CHECKS ALLOW TWO WEEKS • CO. 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 PRODUCTS 8868 Clairemont Mesa Blvd. San Diego, CA 92123 Toll Free 1-800-854-1555 For Orders Only For information or California orders (714) 268-3537 Text continued from 186: ten iterations. In some cases the other parameters are missing because they are not applicable or could not be determined in the amount of time I had on the system. The values for memory size include the complete program memory space, but not the 8190 byte flag array. The time required to compile and load (where applicable) was mea- sured by setting up a command lan- guage file (via such commands as SUBMIT in CP/M or "shell" in UNIX) to control the compilation, loading, and execution. Compile tim- ing began with the carriage return on the SUBMIT line, and ended as the program began execution, as evi- denced by the beginning message "10 iterations". All the 8-bit systems ex- cept the Apple used 8-inch single- density floppy drives, and all Z80-based systems ran at a 4 MHz clock rate with no wait states (ie: pro- Text continued on page 194 Tables and listings continued on page 192 Listing 8: Implementation of the Sieve program, written in PLMX. /* Eratosthenes Sieve Prime Number Program in PLMX */ CPRIME: DO; DECLARE CR LITERALLY '13', LF LITERALLY '10' ; DECLARE TRUE LITERALLY '1', FALSE LITERALLY '0'; DECLARE SIZE LITERALLY '8190'; DECLARE FLAGS (2000H) BYTE, NBFR(10) BYTE; DECLARE ( I, PRIME, K, COUNT, ITER, STATUS) ADDRESS; DECLARE DPRIMES (*) BYTE DATA ('%D PRIMES'); DECLARE BUFFER (*) BYTE DATA ('10 ITERATIONS ' ,CR, LF) NMOUT : PROCEDURE (VALUE, BASE, LC,BUFFADR, WIDTH) EXTERNAL; DECLARE ( VALUE, BUFFADR) ADDRESS; DECLARE (BASE, LC, WIDTH) BYTE; END NMOUT; WRITE: PROCEDURE (FUNCTION, BUFFER, COUNT, STATUS) EXTERNAL; DECLARE (FUNCTION, BUFFER, COUNT, STATUS) ADDRESS; END WRITE; CALL WRITE (0, . BUFFER, LENGTH (BUFFER) , .STATUS) ; DO ITER= 1 TO 10; COUNT = 0; DO I = TO SIZE; FLAGS (I) = TRUE; END; DO I = TO SIZE; IF FLAGS (I) = TRUE THEN DO; PRIME =1+1+3; K = I + PRIME; DO WHILE K <= SIZE; FLAGS (K) = FALSE; K = K + PRIME; END; COUNT = COUNT + 1; END; END; END; CALL WRITE (0, . DPRIMES , LENGTH (DPRIMES) , .STATUS) ; CALL NMOUT (COUNT, 10,' ' , .NBFR, 10) ; CALL WRITE(0 , .NBFR, 10, .STATUS) ; END CPRIME; Listing 9: Implementation of the Sieve program, written in FORTH. ( Eratosthenes Sieve Prime Number Program in FORTH ) 8190 CONSTANT SIZE VARIABLE FLAGS SIZE ALLOT : DO-PRIME FLAGS SIZE 1 FILL ( SET ARRAY ) ( COUNT ) SIZE DO FLAGS I + C@ IF I DUP + 3 + DUP I + BEGIN DUP SIZE < WHILE OVER PRIME + C! DROP DROP 1+ THEN LOOP ." PRIMES" ; OVER + REPEAT 190 September 1981 © BYTE Publications Inc Glitch-proof motion controller makes all the right moves. At the right price. The PC-400 is the latest in simpli- fied, economical motion control for machines and processes from G&L. And, it will control more motions than any other programmable controller. Right this minute it is doing glitch-proof duty in more than 100 closed loop servo installa- tions, controlling lathes, drills, assembly lines, balancers, transfer lines, automatic welders, flame cutters and automated factories. The versatile PC-400 uses the familiar ladder diagram for pro- gramming. Feedback can be resolver, encoder, potentiometer or Inductosyn*. It calls subroutines by letter from the ladder diagram to simplify programming. And the PC-400 can be operated in the "interrupt" mode where subroutines can be executed on a precise 2-, 4-, or8-millisecond basis. G&L maintains an extensive subroutine library for PC-400 users: for example, 8 channel D/A and A/D, video display, servo positioning, LED digital readout, step motor control, digitizing, etc. G&L PC-400. We'll supply application notes for each subroutine . . . purpose, parameters, hardware require- ments, and ladder diagram examples. For complete details, plus facts about our free one-day PC-400 seminars (to be held in major cities coast to coast this year), write: Giddings & Lewis Electronics Co., P.O. Box 1658, 666 S. Military Rd., Fond du Lac, Wl 54935, U.S.A. Telephone (414) 921-9400. 'Trademark of the Inductosyn Corporation for electrical measurement apparatus. H GIDDINGS & LEWIS Electronics Division Circle 147 on inquiry card. BYTE September 1981 191 Language Compiled Total Compile and Execute Ratio and Machine Bytes Size (Bytes) Load (Seconds) (Seconds) to PUI-80 Digital Research PL/1-80, Z80 242 5977 112 14.0 1.00 Whitesmiths C, Z80 290 7384 242 15.6 1.11 TSW RATFOR, Z80 203 2370 103 16.5 1.18 Microsoft FORTRAN, Z80 228 5953 88 17.0 1.21 Pete Ridley's ZSPL, Z80 230 3787 75 18.4 1.31 Interactive Systems ZC, Z80 292 897 n/a 18.5 1.32 Microsoft BASIC compiler 306 16918 144 18.6 1.32 (using integer variables) Z80 M T Microsystems Pascal MT + , Z80 308 3043 102 19.0 1.35 SCI PLMX, Z80 340 1063 116 22.5 1.60 BD Systems C version 1.0, Z80 493 3834 50 35.0 2.50 Intel PL/M MDS, 8080 268 — — 48.0 3.43 BD Systems C version 1.32, Z80 375 3932 31 49.5 3.53 UCSD Pascal, Pascal-100 298 — 12 54.0 3.86 fig-FORTH, Z80 — — — 85.0 6.07 Ithaca Intersystems Pascal/Z, Z80 761 3328 124 109 7.78 JKL FORTH, Z80 — — — 112 8.00 Atari Pascal, Atari 800 176 8192 — 190 13.57 UCSD Pascal, Z80 282 8282 14 239 17.07 Miller Microcomputer Systems — — — 253 18.07 MMSFORTH, TRS-80 Model I (Z80) FORTH 6502 — — — 265 19.93 UCSD Pascal TRS-80 Model II (Z80) 282 8282 60 274 19.57 SWEET 16 (Apple II) — — — 292 20.86 JKL FORTH MDS, 8080 — — — 440 31.43 Pascal/M, Z80 301 21933 50 450 32.14 JRT Pascal, Z80 232 11498 65 470 33.64 CBASIC2 (integer variables), Z80 — — 26 484 34.57 UCSD Pascal, Apple II (6502) 287 — 43 516 36.86 Microsoft BASIC compiler 332 21473 150 715 51.07 (using real variables), Z80 tiny-c 2 (compiler), Z80 — — 96 930 66.42 CBASIC2 (using real variables), Z80 — — — 1430 102.14 Microsoft MBASIC, Z80 — — — 1920 137.14 Microsoft MBASIC, TRS80 Model II (Z80) — — — 2250 160.71 Apple Integer BASIC, 6502 — — — 2320 165.71 Applesoft (real) BASIC, 6502 — — — 2806 200.43 Commodore PET BASIC, 6502 — — — 3180 227.14 Computerware BASIC, 6809 — — — 4303 307.30 tiny-c, Z80 — — — 4720 337.10 Microsoft COBOL version 2.2, Z80 786 17605 146 5115 365.30 Table 2: Comparison of programs running on 8-bit machines. Listing 10: Implementation of the Sieve program, written in COBOL. The TABLE variable was implemented differently in Microsoft COBOL-80 because of its limitation on the length of an array. Eratosthenes Sieve Prime Number Program in COBOL IDENTIFICATION DIVISION. PROGRAM-ID. PRIME. ENVIRONMENT DIVISION. CONFIGURATION SECTION. DATA DIVISION. WORKING-STORAGE SECTION. 01 MISC. 03 I PIC 9(4) COMP. 03 PRIME PIC 9(5) COMP. 03 K PIC 9(4) COMP. 03 TOTAL-PRIME-COUNT PIC 9(4) COMP. 2 TABLE. 04 FLAGS PIC 9 COMP OCCURS 8191 TIMES. PROCEDURE DIVISION. P. DISPLAY ' 1 iteration'. PERFORM ITER-ROUTINE 10 TIMES. DISPLAY TOTAL-PRIME-COUNT ' primes'. STOP RUN. ITER-ROUTINE. MOVE ZEROES TO TOTAL-PRIME-COUNT. PERFORM TABLE-FILLER-ROUTINE VARYING I FROM 1 BY 1 UNTIL I ■ 8191. PERFORM DETAIL-COMPARE THRU D-C-EXIT VARYING I FROM BY 1 UNTIL I = 8190. TABLE-FILLER-ROUTINE. MOVE 1 TO FLAGS (I). DETAIL-COMPARE. IF FLAGS (I + 1) =0 GO TO D-C-EXIT. COMPUTE PRIME = I + I + 3 . COMPUTE K = I + PRIME. F1RST1. IF K > 8191 GO TO NEXTl . MOVE TO FLAGS (K + 1) . COMPUTE K = PRIME + K. GO TO FIRST1. NEXTl. ADD 1 TO TOTAL-PRIME-COUNT. DISPLAY 'FOUND PRIME = ' PRIME. D-C-EXIT. EXIT. 192 September 1981 © BYTE Publications Inc Circle 265 on inquiry card. Tiny BASIC MICROCOMPUTER K-8073 The Engineer's Product Development Board Level Computer LOW COST POWERFUL/VERSATILE ENGLISH-LIKE PROGRAMMING ft IK Byte Local RAM Ext. Expandable To 9K ART/RC Master, For Single Wire Data I/O Of 128 Slave Units Real Time Clock W/Ext. Battery Backup Yr, Mo. Wk, Day. Hour. Sec. RS-232ForCRT 110-4800 Baud K-8073 SINGLE UNIT THIS IS AN ENGINEER'S COMPUTER. Simply attach a CRT, connect 5 volts, and you have yourself one each powerful, versa- tile microcomputer that YOU can program. If you're fed-up with board level compu- ters that require expensive development sys- tems plus the skills of an Assembly language programmer, then you need the K-8073. With an on-chip microinterpreter and the extra control devices we designed into the board, you can do your own programming in the most simple English-like language available — Tiny BASIC. Sophisticated application de- signs can be implemented in hours instead of days or weeks because you have eliminated expensive and time consuming hardware and software costs. IN ADDITION TO ALL THIS, the K-8073 offers advantages unheard of in other board level computers. Among these are an on- board EPROM Programmer, A Real Time Clock, Autostart, IK Byte local RAM for variables, 8K Byte EPROM, ART/RC and PPI W/24 line I/O. STD (MOD) BUS 4.5 x 6.5 in. 5 Volt Only— Cassette Tape In/Out— 2 Sense— 3 Flags INS8073 Microinterpreter Tinv BASIC Processor Autostart EPROM 2K Bvte Utilities Firmware, For Software Dev., EPROM 2K EPR0M-2K Byte EPROM Programmer, 2K Bvte Prm. Decoded— Req. Ext. 25V Only PPI, Programmable I/O, 24 Lines PPI Interface Ribbon Connector THE K-8073 IS FOR OEM'S AS WELL AS END USERS. Whether you manufacture Industrial Process Control, Environmental or Test/Measurement systems, or simply for your own use, you can count on top quality performance. The K-8073 comes complete with all socketed devices including the powerful F-2 Utilities Firmware and a Hardware/Software manual. In Industry, Education, or New Product Development, the K-8073 provides you with State-of-the-Art technology for micropro- cessor efficiency and ease. With a full line of support products, the TransWave line takes care of your every need at the most reason- able prices. To order your K-8073 or for further infor- mation, write or call TRANSWAVE COR- PORATION.Cedar Valley Building, Vanderbilt, PA 15486, (412)628-6370. Development Station $195.00 II I111HWMI COMPUTER DIVISION OF UTSC Language Compiled Total Compile and Execute Ratio and Machine Bytes Size (Bytes) Load (Seconds) (Seconds) to PUI-80 Assembly language 68000 (8 MHz) — — — 1.12 0.08 C, PDP-11/70 130 1406 3.87 1.52 0.11 Assembly language, 8086 (8 MHz) — — — 1.90 0.13 NBS Pascal, PDP-11/70 333 1920 2.68 2.60 0.19 Onyx C (UNIX), Z8000 242 5462 54 3.20 0.23 Assembly language, 8088 (5 MHz) — — — 4.00 0.28 NBS Pascal, PDP-11/60 333 — 18 4.50 0.32 C, PDP-11/40 130 1406 13.8 6.10 0.43 Assembly language, Z80 113 896 68 6.80 0.48 M T Microsystems Pascal MT 68000 (4 MHz) 410 — n/a 9.00 0.64 Intel Pascal-86, 8086 274 4461 267 9.05 0.65 (MDS286FD, 5 MHz) RSI Pascal, 68000 (4 MHz) 318 5376 — 10.2 0.73 RATFOR, HP-3000 — — 44 10.0 0.71 FORTRAN, HP-3000 — — 34 10.0 0.71 DECUS FORTH, PDP-11/70 — — — 11.8 0.78 SUPERSET (Superset Model PGM) 138 — 114 12.0 0.86 Motorola Pascal, 68000 387 12802 82 14.0 1.00 Pascal, HP-3000 — — 100 20.0 1.42 COBOL, HP-3000 — — 26 58.0 4.14 BASIC, HP-3000 — — — 60.0 4.28 Polyforth, Texas Instruments 990/10 — — — 60.2 4.30 UCSD Pascal, Pascal Microengine 298 8282 8 63.0 4.50 UCSD Pascal, Terak LSI-11 282 8282 16 317.0 22.64 C, PDP-11/70 (using division algorithm) 250 1454 3.95 106.0 57.60 Table 3: Comparison of progr ams running on the larger machines. 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If all the antecedents are found to be true, the program can use the rule to assert the truth of all the consequents. The rules are terminated by the string "STOP". In addition to the rules, the pro- CHEETAH GIRAFFE ZEBRA Trii (AND) 7YN LONG LEGS BLACK STRIPES OSTRICH n\ LONG NECK PENGUIN FEATHERS SWIMS FLIES LAYS EGGS Figure 5: A sample network for a simple rule-based system. Boxes represent assertions, circles represent ways of combining asser- tions, and the labels Rl, R2, etc, identify rules. The diagram corresponds to the rules given in lines 3880 through 4080 of listing 1. 274 September 1981 © BYTE Publications Inc compuTER Devices AVAILABLE NOW ... SYSTEM 2800 FROM SYSTEMS GROUP FEATURES • IEEE S-100 Bus Compalible Systems, Z80A • Table Top or Rack Mountable awwHk. * Two Switched AC Outlets on Rear Panel • Two 8-Inch Drives: Single or Double Sided, « „ v „ ,„ _ . _ „ . , „ . ,-, „. , „ . ,„,,„ 0ne > ear Warranty on Entire System Double Density Floppy Disk Drives or 10MB Winchester Hard Disk Drive lllnrD ,., ., c . . c -. . ... »-,-,-, t ™ 2812 CP/M, 2 Single Sided Floppies $3775.00 • 20MB Winchester and Tape Backup 2814 CP/M, 2 Double Sided Floppies 4425.00 ..„,,„.,.. . _ , ., . . . 2819 CP/M, 1 10 MB Winchester & • 8-Slot Shielded and Terminated Motherboard . _ , . „. . . _ „,. _. osH 1 Double Sided Floppy 6675.00 C3 O • System Software Selection includes CP/M*, 2824 MP/M, 2 Double Sided Floppies.... 5235.00 MP/M* or OASIS** 2829 MP/M, 1 10 MB Winchester & .. , ., w,..,, „ 1 Doubled Sided Floppy.... 7500.00 • Single-User or Multi-User Systems, Expandable to 6 Users S-100 PRODUCTS QUALITY RAM FROM SYSTEMS GROUP • Z-80 4MHZ operation with no wait states • IEEE compatible timing - 200 NS 41 16's • Factory assembled, tested & burned in DMBfi400'64K (Bank Select, shown) $749.00 DM6400 64K 545.00 DM4800 48K 520.00 DM3200 32K 495.00 CONFIGURE A COMPLETE S-100 SYSTEM WITH 2nd GENERATION - PRODUCTS FROM SYSTEMS GROUP. • CPC 2810 (shown) Z-80A processor board (4MHZ) with 4 serial & 2 parallel ports $369.00 • CPC2813 - same as CPC2810 but 2 serial ports onlv $345.00 • I"DC280i/8 - 8" floppy disk controller board, up to 4 single/double sided drives, single or double density $349.00 • INO-2804 -4 channel serial I/O 329.00 • CRA-100 -Cromix* adaptor board.. $55.00 CALL US FOR OUR MOST CURRENT PRICES! •2nd Generation is a trademark of Measurement Systems and Controls. Cromix is a trademark of Cromemco, Inc. Tilt-Back is a trademark of Wabash, Inc. CP/M and MP/M are trademarks of Digital Research. OASIS is a trademark of Phase One Systems. 16K MEMORY EXPANSION KIT $24.00 6502 PRODUCTS For Apple, TRS-80 keyboard, Exidy, and all other systems using 4116 dynamic rams or equi- valent. All IC's are prime Mitsubishi MI 41 16-3, 200 NSEC, burned-in and fully tested. wabash 8" or SVa " flexible diskettes certified 100% error free with manufacturers 5 year limited warranty on all 8" media. Soft sectored in Tilt- back* boxes of 10. (Add $3.00 for plastic library cases) 8" single sided, single density $29 .95 8" single sided, double density 37.95 8" double sided, double density 48.95 5 l, 4" single sided, single density 27.95 5 1 ■»" single sided, double density 29.95 Adds Viewpoint CRT.... 589.00 8" DISK DRIVES Shugart 801R $390.00 NEC FD1160 (double sided) 595.00 Memorex MRX-101 8" Winchester style, hard disk drive, 10 megabytes $2,000.00 *% Mr4' -'^'Wiii* BETA 32K BYTE EXPANDABLE BAM FOB 6502 AND 6800 SYSTEMS AIM 65 KIM SYM PET S44-BUS • Plug compatible with the AIM-65/SYM expan- sion connector by using a right angle connec- tor (supplied). • Memorv board edge connector plugs into the 6800 S44 bus. • Connects to PET using an adaptor cable. • Uses +5V only, supplied from the host com- puter. • Full documentation. Assembled and tested boards are guaranteed for one full year. Purchase price is fully refundable if board is returned. undamaged within 14 days. Assembled with 32K RAM $349.00 & Tested with 16K RAM 329.00 Bare board, manual & fi hard-to-get parts. 99.00 PET interface kit. Connects the 32K RAM board toa4Kor8KPET $ 69.00 TERMS: Minimum order $15.00. Minimum shipping and handling $3.00. Calif, residents add 6 c '( sales tax. Cash, checks. Mastercard. Visa and purchase orders from qualified firms and institutions arc accepted. Product availabili- ty and pricing arc subject to change without notice. INTERNATIONAL ORDERS: Add 15% to pur- chase price for all orders. Minimum shipping charge is $20.00. Orders with insufficient funds will be delayed. Excess funds will he returned with your order. All prices arc U.S. only. compuTER Devices 1930 W.COUini AVE. ORAHGE, Cfl 99668 (714)635-7980 gram uses a set of hypotheses, which appear in the DATA statements in lines 4240 through 4250. In this case, the hypotheses are that the animal is either an albatross, a penguin, an ostrich, a zebra, a giraffe, a tiger, or a cheetah. The goal of the program is to establish the truth of one of these hypotheses. The program operates by trying the hypotheses one at a time. For each hypothesis, the program scans the list of rules to see if the hypothesis can be deduced. If so, the antecedents for the relevant rules become new sub- hypotheses to be established, and the program looks for rules for deducing these antecedents. The program chains backward through the rules until no deductions can be made, at which point the program asks the user if the subhypothesis it is working on is true. The core subroutine that im- plements this strategy is called VERIFY (see lines 1210 through 1830). VERIFY tries to determine if its argument Fl$ is true. The argument Fl$ represents a hypothesis or sub- hypothesis. If the truth of Fl$ has already been recorded, VERIFY returns immediately. If there are no rules for deducing Fl$, and if VERIFY has not asked the user about Fl$ before, it asks. Otherwise, VERIFY applies TRYRULE+ to each of the rules in turn until it either meets with success or exhausts the rules. The only thing that complicates the coding of this simple strategy is that TRYRULE+ uses TESTIF+ to see if all the antecedents for the rule are true, and TESTIF+ checks the antecedents by calling VERIFY. Thus, VERIFY is recursive, and BASIC does not support recursion. Therefore, all the reentrant subroutines must ex- plicitly save their local variables on push-down stacks before transferring control to one another, restoring those values upon return. To see one reason why AI workers prefer LISP, which takes care of all this bookkeep- ing automatically, you need only Listing 2: A sample run of the identification program shown in listing 1, The program asks questions and makes deductions, when possible, based on the answers. The pro- gram always cites the rule used to make a deduction. to try to establish one of the Hello. I will use my 15 rules following 7 hypotheses ANIMAL IS ALBATROSS ANIMAL IS PENGUIN ANIMAL IS OSTRICH ANIMAL IS ZEBRA ANIMAL IS GIRAFFE ANIMAL IS TIGER ANIMAL IS CHEETAH Please answer my questions with Y (yes), N (no), or W (why). Is this true ANIMAL HAS FEATHERS ?N Is this true: ANIMAL FLIES ?N Is this true: ANIMAL HAS HAIR ?Y Rule Rl deduces ANIMAL IS MAMMAL Is this true: ANIMAL HAS HOOFS ?N Is this true: ANIMAL CHEWS CUD ?N Is this true: ANIMAL EATS MEAT ?Y Rule R5 deduces ANIMAL IS CARNIVORE Is this true: ANIMAL HAS TAWNY COLOR ?Y Is this true: ANIMAL HAS BLACK STRIPES ?W I am trying to use Rule RIO I already know that: ANIMAL IS MAMMAL ANIMAL IS CARNIVORE ANIMAL HAS TAWNY COLOR IF: ANIMAL HAS BLACK STRIPES THEN. ANIMAL IS TIGER Is this true: ANIMAL HAS BLACK STRIPES ?N Is this true: ANIMAL HAS DARK SPOTS ?Y Rule R9 deduces ANIMAL IS CHEETAH I conclude that ANIMAL IS CHEETAH. glance at the simpler version of this same program in Winston and Horn's book. Pascal would be a better language than BASIC for our program because Pascal supports recursion and allows user-defined data structures (eg: using records and the type statement), as well as providing an easy-to- understand block structure. We chose to write this program in BASIC rather than Pascal because more personal computers have BASIC. (We hope our use of BASIC will not contribute to the perpetuation of this condition!) Listing 2 shows an example of the dialogue when the user was thinking of a cheetah. A look at the rules shows why the program asked the questions it did. Working the first hypothesis (albatross), the program tried to use rule Rl5, which set up the subgoal of seeing if the animal was a bird. Rules R3 and R4 were relevant, so the program tried rule R3 and asked if the animal had feathers. The program soon ruled out the possibili- ty of a bird, so it skipped the penguin and ostrich hypotheses. Working on rule Rl2 for the zebra hypothesis, on rule Rll for the ungulate sub- hypothesis, and on rule Rl for the mammal sub-subhypothesis, the pro- gram successively established that the animal was a mammal, was not an ungulate, and was a carnivore called a cheetah. It is worth noting that the backward-chaining strategy is dif- ferent from the classical divide-and- conquer approach used in binary search. With four well-chosen ques- tions, it is possible to make the one- out-of-fifteen decision that required nine questions in this example. Before concluding that rule-based programs are hopelessly inefficient, you should note that the rules do make use of subclasses and sub-subclasses, much as is done in binary search. Thus, once it is learned that the animal is not a bird, for example, no more questions concerning birds will be asked. The main difference is that this particular program does not ask directly if the animal is a bird, but rather asks for primitive observations that allow "birdness" to be deduced. 276 September 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 8 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 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 Con trol-S entry. And simultaneous on-screen display ,-i( Inul \-,r,,nn nrintni-t ! " * S-'/A ' ( ) * + , - . / 01234567B9: ;<=>? fflBCDEFGHIJKLHNO PORSTUVWXYZ[ \] A _ 'dbcdtftjhi lklmno 7X12 MATRIX 18X80 OPTIONAL Advanced Hardware Design Available Options Firmware _...ng utilizing ..., of text being printed Pascal 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. Other The new Microsoft Softcard' is supported. So is the popular D. C. Hayes Micro- Boards 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) to 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 onboard 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, AM 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 1 keyboard. 1K of on-board ROM firmware controls all operation of the VIDEOTERM. No machine language patches are needed for normal VIDEOTERM use. Characters Options (12349(715 M «■>? MBCDEF 6H I JKLMNO f t » S T V U X Y Z [ \ ] t . 'abcdefgh i jk (ana pqrstuvwxyzf I i"f 7X9 MATRIX 24X80 STANDARD 7x9 matrix 7 x 12 matrix option; Alternate user definable character set option: Inverse video option. Firmware Version 2.0 Display 24 x 80 (full descenders) 18 x 80 (7 x 12 matrix with full descenders) Want to know more? Contact 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. Apple II' 15 a trademark ol Apple Computer Inc ROMWriter' is a trademark ol Mountain Hardware Inc Mictomodem II' is a trademark of D C Hayes Associales Inc Softcard" is a trademark ol Microsoft EasyWriter - is a trademark of Information Unlimited Software Inc • 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 I Videx litis fhe 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 )ust like a typewriter If you want an upper case character, use the SHIFT key or the CTRL key for shift lock Not only thai, 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 lor use with all revisions of the APPLE II. It includes 6 ICs, and EPROM a\u\ 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) S129. Apple II' is a trademark of Apple Computer. Inc ffl m VIDEX 897 N.W. Grant Avenue Corvallis, Oregon 97330 Phone (503) 758-0521 Circle 390 on inquiry card. BYTE September 1981 177 To gain efficiency, you might want to change the program so it will ask the user about intermediate hypotheses, resorting to deduction only when the user gives a "don't know" response. This illustrates how the rule-based approach actually pro- vides great flexibility by separating the control strategy (as implemented in VERIFY) from the knowledge base (as represented by the rules). The rule-based identification system just described is at best a toy. Although this system illustrates the important principle of the separation of the rule base from the general- reasoning program, the system lacks many important features included in state-of-the-art research systems. Among the features present in most state-of-the-art knowledge-based systems, but lacking in our toy pro- gram, are the following: • immediate propagation of in- ferences • negative inferences • plausible inference's ability to han- dle mutually exclusive categories • contextual constraints • degrees of certainty in user's answers Tune tip your LA36 The DS120 Terminal Controller makes your LA36 perform like a DECwriter • III. The Datasouth DS120 gives your DECwriter" II the high speed printing and versatile performance features of the DECwriter" III at only a frac- tion of the cost. The DSI20 is a plug compatible replacement for your LA36 logic board which can be installed in minutes. Standard features include: • 165 cps bidirectional printing • Horizontal & Vertical Tabs • Page Length Selection • 110-4800 baud operation • 1000 character print buffer • X-on. X-off protocol •Self Test • RS232 interface • 20 mA Current Loop interface • Top of Form • Adjustable Margins • Double wide characters • Parity selection • Optional APL character set Over 5,000 DS120 units are now being used by customers ranging from the Fortune 500 to personal computing enthusiasts. In numerous instal- lations, entire networks of terminals have been upgraded to take advan- tage of today's higher speed data communications services. LSI -- ... t m _,^,,. microprocessor electronics ^'ii Efs fo and strict quality control en- sure dependable performance for years to come. When ser- vice is required, we will respond promptly and effec- tively. Best of all, we can de- liver immediately through our nationwide network of distributors. Just give us a call for all the details. * M AP data computer corporation 4740 Dwight Evans Road • Charlotte, North Carolina 28210 • 704/523-8500 • information volunteered by the user • flexible control structure But toys are fun, and are often ef- fective teachers. Enjoy. ■ References 1. Balzer, R, L D Erman, P London, and C Williams. "HEARSAY-HI: A Domain- Independent Framework for Expert Systems." Proceedings of the First Annual National Conference on Artificial Intelligence, 1980, pages 108 through 110. 2. Barstow, D R. "An Experiment in Knowledge-based Automatic Program- ming." Artificial Intelligence, volume 12, August 1979, pages 7 through 119. 3. Bennett, J S and R S Engelmore. "SACON: A Knowledge-Based Consul- tant for Structural Analysis." Pro- ceedings of the Sixth International Joint Conference on Artificial Intelligence, August 20-23, 1979, pages 47 through 49. 4. Brown, J S, R R Burton, and A G Bell. "SOPHIE: A Sophisticated Instructional Environment for Teaching Electronic Troubleshooting (An Example of Al in CAI)." Final Report, Contract F41609-73-C-006, Bolt, Beranek, and Newman Inc, Cambridge MA, March 1974. 5. Buchanan, B G and T M Mitchell. "Model-Directed Learning of Production Rules." Pattern-Directed Inference Systems, D A Waterman and F Hayes- Roth (editors), New York: Academic Press, 1978, pages 297 through 312. 6. Bundy, A, et al. "Solving Mechanics Problems Using Meta-Level Inference." Expert Systems in the Microelectronic Age, D Michie (editor), Edinburgh: Edin- burgh University Press, 1979, pages 50 through 64. 7. Carbonell, J R. "Al in CAI: An Artificial- Intelligence Approach to Computer- Aided Instruction." IEEE Transactions on Man-Machine Systems, volume MMS-11, December 1970, pages 190 through 202. 8. Clancey, W J, E H Shortliffe, and B G Buchanan. "Intelligent Computer-Aided Instruction for Medical Diagnosis." Pro- ceedings of the 3rd Symposium on Com- puter Application in Medical Care, 1979, pages 175 through 183. 9. Davis, R. "Interactive Transfer of Exper- tise: Acquisition of New Inference Rules." Artificial Intelligence, volume 12, August 1979, pages 121 through 157. 10. Davis, R and J King. "An Overview of Production Systems." Machine Intelligence 8, E W Elcock and D Michie (editors), New York: Wiley, 1976, pages 300 through 332. 1 1 . Duda, R O, J G Gaschnig, and P E Hart. "Model Design in the Prospector Con- 278 September 1981 © BYTE Publications Inc Circle 105 on inquiry card. BASF FlestyDisk 1 No. More than four decades of experi ence in magnetic media -BASF invented magnetic recording tape, the forerunner of today's wide range of magnetic media, back in 1934, and was the first independent manufacturer of IBM-compatible floppy disks. Tough Tyvek sleeve - no paper dust, no static electricity. *$* I Special self-cleaning jacket and liner help eliminate data errors and media wear and tear. Cross-linked oxide coating- for low head wear and long trouble- free media life. Bi-axially oriented polyester substrate - for uniform and reli- able performance year after year. Total capability— one of two man- ufacturers in the world that makes both 8" and 5.25" models, has tape and disk experience, and manufactures floppy disk drives. Double lubrication -lubricants both in the formula and on the disk surface, to minimize media wear due to head friction. Packaging to suit your requirements -standard flip-top box , Kassette 10® storage case, or bulk pack. 100% certification — every single disk is tested at thresholds 2-3 times higher than system require- ments, to be 100% error-free. For the name of your nearest supplier, write BASF Systems, Crosby Drive, Bedford, MA 01730, or call 617-271-4030. BASF Floppy Disks Mag Cards Cassettes Computer Tapes Disk Packs Computer Peripherals Circle 36 on inquiry card. APPLESOFT® Basic Compiler $167.50 Compiles APPLESOFT' BASIC programs into native 6502 code, allowing programs to run up to 10 times faster. Handles graphics and shape tables. Requires 48K, autostart ROM, language system and at least one drive. List Price: $200.00 Microhouse SPELLSTAR New! Option for Wordstar. Compares words in your text to its 20,000-word compressed dictionary. Jumps back to WordStar for correction of errors or addition of new words to the dictionary. Price includes update of registered 2.x and earlier WordStar (must send master disk). List Price: $250.00 Microhouse Price: S165.00/NA WORDSTAR Version 3.0! Now leaturing horizontal scrolling and column moves. List Price: $495.00 Microhouse Price: $322.00/840.00 WORDSTAR for APPLE List Price: $375.00 Microhouse Price: $245.00/840.00 WORDSTAR CUSTOMIZATION NOTES Package includes manual and diskette. List Price: S150.00 Microhouse Price: S95.00/NA MAILMERGE Option for Wordstar. List Price: $150.00 Microhouse Price: 8110.00/840.00 MAILMERGE for APPLE List Price: $125.00 Microhouse Price: 885.00/825.00 VISICALC for APPLE List Price: $150.00 Microhouse Price: S107.00/NA SUPERSORT I List Price: $250.00 Microhouse Price: $170.00/840.00 SUPERSORT II List Price: $200.00 Microhouse Price: $145.00/840.00 SUPERSORT for APPLE List Price: $200.00 Microhouse Price: $130.00/840.00 DATASTAR List Price: $350.00 Microhouse Price: $245.00/840.00 WORDMASTER List Price: $150.00 Microhouse Price: $119.00/840.00 CALL OR WRITE FOR FREE CATALOG MICROSOFT BASIC 80 List Price: $350.00 Microhouse Price: 8273.00/830.00 MICROSOFT BASIC 80 COMPILER Language compatible with MBASIC but code runs 3-1 Ox faster. List Price: $395.00 Microhouse Price: $308.00/830.00 MICROSOFT FORTRAN 80 Compiler is ANSI '66 compatible (except for COMPLEX). List Price: $500.00 Microhouse Price: $345.00/830.00 muSIMP/muMATH by Microsoft List Price S250.00 Microhouse Price: $195.00/S25.00 COBOL 80 by Microsoft List Price: S750.00 Microhouse Price: $562.50/$30.00 MACRO 80 by Microsoft List Price: $200 00 Microhouse Price: $140.00/820.00 EDIT 80 by Microsoft List Price: S 120.00 Microhouse Price: $84.00/820.00 WHITESMITHS C List Price: $630.00 Microhouse Price: CALL/830. 00 TINY C Interpreter List Price: $100.00 Microhouse Price: 879.00/850.00 TINYC Compiler List Price: $250.00 Microhouse Price: $195.00/850.00 SPELLGUARD Fast stand-alone program works with nearly any CP/M' word processor. List Price: $295.00 Microhouse Price: $230.00/$25.00 STACKWORKS FORTH For Z80 or 8080 (specify). List Price S175 00 Microhouse Price: $160.00/830.00 WHITESMITHS PASCAL Includes Whitesmiths C Compiler List Price: S850 00 Microhouse Price: CALL/845. 00 Microhouse P0 BOX 498 BETHLEHEM. PA 18016 (215) 868-8219 sultant System for Mineral Exploration." Expert Systems in the Microelectronic Age, D Michie (editor), Edinburgh: Edin- burgh University Press, pages 153 through 167. 12. Fagan, L, J Kunz, E A Feigenbaum, and J Osborn. "Representation of Dynamic Clinical Knowledge: Measurement Inter- pretation in the Intensive Care Unit." Proceedings of the Sixth International Joint Conference on Artificial Intelligence, August 20-23, 1979, pages 260 through 262. 13. Feigenbaum, E A. "The Art of Artificial Intelligence — Themes and Case Studies of Knowledge Engineering." AFIPS Con- ference Proceedings, volume 47, June 1978, pages 227 through 240; also in Ex- pert Systems in the Microelectronic Age, D Michie (editor), Edinburgh: Edin- burgh University Press, 1979, pages 3 through 25. 14. Feigenbaum, E A, B G Buchanan, and J Lederberg. "On Generality and Problem Solving: A Case Study Using The DEN- DRAL Program." Machine Intelligence 6, B Meltzer and D Michie (editors), New York: American Elsevier, 1971, pages 165 through 190. 15. Gaschnig, J G. "Development of Uranium Exploration Models for the Pro- spector Consultant System." Final Report, SRI Project 7856, Artificial Intelligence Center, SRI International, Menlo Park CA, March 1980. 16. Gelernter, H L, etal. "Empirical Explora- tions of SYNCHEM." Science, September 9, 1977, pages 1041 through 1049. 17. Goldberg, R and S M Weiss. "An Experi- mental Transformation of a Large Expert System Knowledge-Base." Working Paper, Department of Computer Science, Rutgers University, New Brunswick NJ, March 1980. 18. Kulikowski, C A. "Artificial Intelligence Methods and Systems for Medical Con- sultation." IEEE Transactions on Pattern Analysis and Machine Intelligence, volume PAMI-2, September 1980, pages 464 through 476. 19. Lesser, V R and L D Erman. "A Retrospective View of the HEARSAY-II Architecture." Proceedings of the Fifth International Joint Conference on Artifi- cial Intelligence, August 22-25, 1977, pages 790 through 800. 20. McDermott, J. "R1: An Expert in the Computer Systems Domain." Pro- ceedings of the First Annual National Conference on Artificial Intelligence, 1980, pages 269 through 271. 21 . Newell, A and H A Simon. "GPS, A Pro- gram that Simulates Human Thought." Computers and Thought, E A Feigen- baum and J A Feldman (editors), New York: McGraw-Hill, 1963. 22. Newell, A and H A Simon. Human Prob- lem Solving. Englewood Cliffs NJ: Prentice-Hall, 1972. 23. Nii, H P and E A Feigenbaum. "Rule- 280 September 1981 © BYTE Publications Inc Circle 222 on inquiry card. Based Understanding of Signals." Pattern-Directed Inference Systems, D A Waterman and F Hayes-Roth (editors), New York: Academic Press, 1978, pages 483 through 501 . 24. Pauker, S G, G A Gorry, J P Kassirer, and W B Schwartz. "Towards the Simulation of Clinical Cognition." American Journal of Medicine, volume 60, June 1976, pages 981 through 996. 25. Pople, H E, Jr, ef a/. "DIALOG: A Model of Diagnostic Logic for Internal Medicine." Proceedings of the Fourth International Joint Conference on Artifi- cial Intelligence, September 1975, pages 848 through 855. 26. Reboh, R. "The Knowledge Acquisition System." "A Computer-Based Consul- tant for Mineral Exploration," R Duda, et a/, Final Report, SRI Project 6415, Artificial Intelligence Center, SRI Inter- national, Menlo Park CA, September 1979. 27. Shortliffe, E H. Computer Based Medical Consultations: MYCIN. New York: Elsevier, 1976. 28. Stallman, R M and G J Sussman. "For- ward Reasoning and Dependency- Directed Backtracking in a System for Computer-Aided Circuit Analysis." Artifi- cial Intelligence, volume 9, 1977, pages 135 through 196. 29. Stefik, M J. "Inferring DNA Structures from Segmentation Data." Artificial Intelligence, volume 11, August 1978, pages 85 through 114. 30. van Melle, W. "A Domain-Independent Production-Rule System for Consulta- tion Programs." Proceedings of the Sixth International Joint Conference on Artificial Intelligence, August 20-23, 1979, pages 923 through 925. 31. Waterman, D A. "User-Oriented Systems for Capturing Expertise: A Rule- Based Approach." Expert Systems in the Microelectronic Age, D Michie (editor), Edinburgh: Edinburgh University Press, 1979, pages 26 through 34. 32. Waterman, D A and F Hayes-Roth. Pattern-Directed Inference Systems. New York: Academic Press, 1978. 33. Weiss, S M and C A Kulikowski. "EX- PERT: A System for Developing Con- sultation Models." Proceedings of the Sixth International Joint Conference on Artificial Intelligence, August 20-23, 1979, pages 942 through 947. 34. Weiss, S M, C A Kulikowski, and A Safir. "Glaucoma Consultation by Computer." Computers in Biology and Medicine, volume 8, 1978, pages 25 through 40. 35. Winston, P H and B K P Horn. LISP. Reading MA: Addison-Wesley, 1981, chapter 18. 36. Wipke, W T. "Computer Planning of Research in Organic Chemistry." Com- puters in Chemical Education and Research, E V Ludena, N H Sabelli, and A C Wahl (editors), New York: Plenum Press, 1976, pages 381 through 391. The New ADDS Viewpoint Video Terminal $649 Features a detachable Tektronics-made keyboard with keypad. Function keys. Reverse video, half-intensity, underlining by fields. Printer port. ADDS Quality construction Microhouse CALL FOR LOW PRICES ON IMS Series 5000 and 8000 Computers C ITOH STARWRITER I Letter-quality printer uses Diablo plastic printwheels and ribbons. 25 cps bidirectional, logic-seeking. Parallel interface. List Price: S 1895.00 Microhouse Price: $1431.00 C ITOH STARWRITER I (Serial) List Price: S 1960.00 Microhouse Price: $1502.00 DIABLO 630 Letter-quality printer uses plastic and metal printwheels. 40 cps, bidirectional, logic-seeking. Optional tractor: S225. List Price: S27 10.00 Microhouse Price: $1999.00 EPSON MX70 Includes GRAFTRAX II dot-addressable graphics. Monodirectional. 80 cps. Adjustable tractor. Parallel only. List Price: S450.00 Microhouse Price: $378.00 EPSON MX80 Removable print head, bidirectional, logic- seeking, adjustable tractor, parallel interface. Easily converted to RS232, IEEE 488, Apple or ATARI. CALL FOR INFORMATION ON THE NEW GRAPHICS ROM PACK! List Price: S645.00 Microhouse Price: $479.00 EPSON MX-80 FT Friction AND tractor feed version of the MX-80. Parallel interface included. Ust Price: S745.00 Microhouse Price: $569.00 TELEVIDEO 910 Terminal List Price: S699.00 Microhouse Price: $595.00 TELEVIDEO 950 List Price: S1 195.00 Microhouse Price: $995.00 CALL OR WRITE FOR FREE CATALOG PRICES AND SPECIFICATIONS SUBJECT TO CHANGE WITHOUT NOTICE [MonsfCoraJ Software Manual S Manual'Only ASK ABOUT THE NEW Televideo COMPUTER SYSTEMS IDS PAPER TIGER 560G List Price: S1 695.00 Microhouse Price: $1464.00 VIDEX VIDEOTERM SPECIAL! Carried over by popular demand. Converts your Apple screen to 80x24 upper and lower case. Purchase VIDEOTERM with WordStar and save! If purchased separately: S290. List Price: $345.00 Microhouse Price: $270.00 MORROW DISCUS 2D 8 inch single-sided double-density floppy disk drive subsystem. Includes CP/M* and MBASIC. List Price: S1199.00 Microhouse Price: $995.00 MORROW HARD DISK SUBSYSTEM 10 Megabyte. Includes S-100 controller card. CP/M-, and enclosure. List Price: $3695.00 Microhouse Price: $3062.00 MICROSOFT APPLE SOFTCARD Purchase the softcard with MicroPro's WordStar and save $70! Converts your Apple li or II plus to a CP/M- system. Includes MBASIC! Price if purchased separately: $295. List Price: $349.00 Microhouse Price: $279.00 TCS/Atlanta INTERACTIVE ACCOUNTING SYSTEM for small businesses. Ver. 5.0. Each package can be used alone or post automatically to the General Ledger. Compiled version (no support language needed). Price listed is per package. Generalledger, Accounts Receivable, Accounts Payable, and Payroll packages available. Call for details on new Order Entry & Inventorypackages. ALSO AVAILABLE FOR APPLE II. Also available in source. List Price: Compare at $530 Microhouse Price: $79.00/$25.00 ALL FOUR TCS PACKAGES (compiled) List Price: Compare at $530/pkg. Microhouse Price: $269.00/$90.00 CP/M is a registered trademark of Digital Research UNIX is a registered trademark of Bell Labs APPLE is a registered trademark of Apple Computers TRS80 is a registered trademark of Tandy Corp. SHIPPING: Add $5 per manual or software package. Add $2.50 for COD orders. Call for shipping charges on other items. Pennsylvania residents add 6 per cent sales tax. Microhouse P.O. BOX 498 BETHLEHEM. PA 18016 1215) 868-8219 Circle 222 on inquiry card. September 1981 © BYTE Publications Inc 281 Print neatly so we know where to send \our check. 282 BYTE September 1981 Buying new software is the pits, isn't it? You read an ad and it sounds terrific, so you ask around, then buy the manual. So far, so good — so you spring several hundred dollars for the package. And it does exactly what they said. But to get exactly what you want, you're going to have to change the way you run your business. Or go through so much hassle that you're not sure it's worth it. So you grit your teeth and suffer, or put it on a shelf to gather dust. Sounds familiar, doesn't it? But there is at least one known exception: an exceptional DBMS called dBASE II. For database fans, an offer you shouldn't refuse. dBASE II is the only high- performance relational Database Management System for micros. And it's the only DBMS that can help you get the DBMS that's right for you, no matter which DBMS you may want. Here's how: If you have a 48k micro with CP/M, send us its model number and the size of your drives along with $700 (CP/M 86 version soon — call if you can't wait). We'll send you a copy of dBASE II that you can run on your system, solving your problems your way, for 30 days. Then just send every- thing back and we'll return your money, no questions asked. During that 30 days, you can find out how much a real database management system can do for you. How it will affect your operations. Exactly what you want done. And precisely how you want to do it. Then even if you go for some other system, you'll be an informed buyer. And it never hurts to know what you're doing. IBM just caught up. So can you. With dBASE II, you'll get the same kind of system for your micro that IBM introduced a few months ago for their mainframes. It's a relational DBMS, and that makes it different from any other micro system you've ever seen. In a relational database, the data is organized as simple tables, with records as the rows and the data fields as the columns, much like your data is organized now. Data rela- tions are logical, so that you can zero in on the specific information you want without knowing a thing about the pre-defined sets, pointers or other cumbersome structures of hierarchal and network DBMS's. And unlike file management systems, dBASE II gives you pro- gram and data independence. You can change your database structure without re-entering your data and without reprogramming, or change some or all of your programs with- out touching your database. And the same database can be used for any number of different applications. dBASE II is a stand-alone applications development system. You don't need an extra support language, because dBASE II comes with its own Applications Devel- opment Language (ADL). With ADL, you can use simple English-like statements to manipulate your data, or use built-in structured constructs to prepare sophisticated applica- tions packages. It's simple and easy to use, yet extremely powerful. You create a new database and start using it in a minute or less. Just type CREATE, then respond to system prompts to name the file and define the fields. Now enter the data. Add data to an existing database instantly, whether your file has AshtonTate ©Ashton-Tate 1981 10 records or 10,000 records, by typing APPEND, then entering the information. UPDATE, MODIFY, JOIN and REPLACE whole databases or individual records and characters. Add or delete fields in your data- base structure without re-entering all your data. And with dBASE II, it's easy to get information out once you've put the data in. Do automatic calculations on fields, records and databases with a few keystrokes. Organize months' worth of data in minutes with REPORT (printing optional), and get your reports today instead of tomorrow. Use the built-in SORT, with single or multiple keys. Or INDEX your data, then FIND it in seconds, even with floppies. You can use dBASE II inter- actively or store a sequence of com- mands to automate your accounting, billing, mailing lists or whatever data you have to manage. You'll wonder how you managed without it. dBASE II is the most powerful, easiest to use DBMS you can get for a micro. And instead of poring over the manual, you can run it hands-on, in-house to see exactly what it can do for you. Try it. What have you got to lose? We even provide the label so you can send it back. Ashton-Tate, 3600 Wilshire Blvd., Suite 1510, Los Angeles, CA 90010. (213) 666-4409. Circle 31 on inquiry card. BYTE September 1981 283 The Atari Tutorial Part 1: The Display List Chris Crawford 1272 Borregas Ave Sunnyvale CA 94086 Editor's Note: Although I have always considered myself an "Apple person" (I have a disk-based Apple II at home), it was exciting to attend a two-day seminar for prospective Atari programmers given by Chris Crawford, Lane Winner, and Mike Ekberg, all of Atari Inc. Once I learned about the inter- nal structure of the Atari 400 and 800 computers, I realized the tremendous potential these machines have. We at BYTE are proud to present "The Atari Tutorial, " a series of articles written by members of the Atari staff. The subjects include: the display list, graphics indirection and character sets, player-missile graphics, display-list interrupts, scrolling, and Atari BASIC. This series of articles is adapted from De Re Atari, a forthcoming book on the internal structure of Atari computers, to be published in December 1981 by Atari Inc. This first article, which is on display lists, is by Chris Crawford, who with Lane Winner coauthored the article "An Introduction to Atari Graphics," which we published in the January 1981 BYTE, page 18. "The Atari Tutorial" will cover in greater detail many of the interesting points only mentioned in the first article. We hope you enjoy the series.... GW The Atari personal-computer system is a second-generation per- sonal computer. First and foremost, it is a consumer computer. The entire thrust of its design is to make the con- sumer comfortable with the com- puter. This consumer orientation reveals itself in many ways. First, the consumer is protected from mistakes by items such as keystone-shaped connectors that cannot be inserted the wrong way, a power interlock that turns the computer off when internal electronics are exposed, and a pair of plastic shields protecting the system reset key. Second, the machine has a great deal of graphics power; people generally respond to pictures much more readily than to text. Third, the machine has good sound capabilities; again, people normally respond to This article appears in slightly different form in De Re Atari, a book published by Atari Inc, and is reproduced with its express permission. direct sensory input better than to in- direct textual messages. Finally, the computer has joysticks and paddles for more direct tactile input than is possible with keyboards. The point is not that the Atari personal-computer system has a lot of features, but rather that the features are all part of a consistent design philosophy aimed at the consumer. The designer who does not appreciate this fundamental fact will be working against the grain of the system. The internal layout of the Atari 400 and 800 computers (which are elec- trically equivalent to each other) is very different from that of other systems. They do have a micro- processor (a 6502), RAM (random- access read/write memory), ROM (read-only memory), and a PIA (peripheral interface adapter). However, they also have three special-purpose LSI (large-scale in- tegration) devices known as ANTIC, POKEY, and CTIA. These devices were designed by Atari engineers primarily to take much of the burden of housekeeping from the 6502, free- ing the 6502 to concentrate on com- putations. While they were at it, they designed a great deal of power into these devices. Each is almost as big (in terms of silicon area) as a 6502, so the three of them together provide a tremendous amount of power. Mastering the Atari 400/800 is primarily a matter of mastering these three chips, a task we hope will be aided by this series of tutorial articles. Principles of Television Display In order to understand the graphics capabilities of the Atari personal- computer system, you must first understand the rudiments of how a television set works. Television sets use a raster-scan display system. An electron beam is generated at the rear of the television tube and shot toward the screen. Along the way, it passes between sets of horizontal and ver- tical coils or plates that, if energized, can deflect the beam to make it strike any point on the screen. The elec- tronics inside the television set cause the beam to sweep across the screen in a regular fashion. The beam's in- tensity can be controlled: if you make the beam more intense, the spot being struck on the screen glows brightly; if you make it less intense, the spot glows dimly or not at all. The beam starts at the top left cor- ner of the screen and traces horizon- tally across the screen. As it sweeps across the screen, the changes in in- tensity paint an image on the screen. When the beam reaches the right edge of the screen, it is turned off, brought 284 September 1981 © BYTE Publications Inc jcippkz computer MEANS BUSINESS / JH ft APPLE II PLUS HP-85 A STANDARD FOR PROFESSIONALS HP-67 289.95 HP-97 584.95 HP-33C SCI. . . . 79.95 HP-34C SCI. . . . 114.95 HP-38C BUS RE 119.95 HP-32E SCI 49.95 HP-37E BUS 59.95 HP-41.41CV CALL HP-85 CALL HP-83 NEW CALL U.S.A. AUTHORIZED DEALER AND LEVEL 1 SERVICE CENTER NOW AVAILABLE: • I6K. 32K. 48K • MODEM • DOS 3.3 • DOW JONES NEWS • APPLE PLOT & QUOTES • APPLE PASCAL 64K • DECISION • APPLE FORTRAN EVALUATOR • VISICALC 16 SEC -CONTROLLER • APPLE WRITER |Gen Ledger] • GRAPHICS TABLET . MICRO COURIER • BPI |GL. AR. PAYROLL] COMPLETE BUSINESS, EDUCATIONAL & GAME SOFTWARE AVAILABLE. EPSON CENTRONICS QUME SILENTYPE ANADEX SANYO. BW. COLOR. GREENSCREEN EXTENDED WARRANTY HP-41C Complete Enhancements, Peripherals and Accessories The PHONE CONTROLLER BY DICTOGRAPH NOW 99.95 Dials any of 30 slored numbers Quart* clock displays time and elapsed time automatically Automatically re-tnes a busy phone a number of pre-programmed times Built-in speaker for group listening For home and business use YOU'LL WONDER HOW YOU EVER GOT ALONG WITHOUT IT. CODEvfl-PHONE The Telephone Answering System® NOW SAVE 1000 ECONOMY ANSWER 79.95 • 60. • LIMITED QUANTITIES • 1450 SMALL WONDER 169.95 • 110. 1550 TOUCH SYSTEM 249.95 • 130. 1750 VOICE ACTIVATE 219.95 • 110. 960 MEMORY DIALER HANDHELD 99.95 NEW * EXTRA CODER FREE WITH PURCHASE OF ANY C-A-P REMOTE - WHERE MIRACLES NEVER CEASE TOSHIBA NOW BC-1232PV 99 95 DIGITRON ^.^o DESK TOP CALCULATOR 12-QIGIT PRINT DISPLAY FOR FAST ACCURATE CALCULATING AT HOME OR FOR BUSINESS W-100 DEPTH-TESTED TO 100 METERS NOW 39.95 CA-90 INVADER GAME CALCULATOR WATCH AA-81 2-WAY DIG ANALOG ALARM VL-TONE MUSICAL INSTRUMENT CALC . W100 DEPTH TESTED ALARM CHRONO. . FX7100 SCI CHRCNO ALARM CALC FX3500 SCI PROGRAMMABLE CALC 49.95 69.95 69.95 39.95 49.95 39.95 FR100 DESK-TOP PRINT DISPLAY 79^95 ALSO: CANON. TOSHIBA. NSC. SEIKO. MATTEL. PEARLCORDER. ITT. GTE. AND MANY OTHERS ALL AT GREAT PRICES! INNOVATIONS FROM Texas Instruments *FREE SPEECH SYNTHESIZER WITH PURCHASE OF TI-99/4 TI-54 SCI NEW 39.95 SPEAK & SPELL. READ 59.95 TI-5511 NEW 44.95 SPEAK & MATH 59.95 TI-57 PROG SCI 39.95 TOUCH S TELL NEW 54.95 PC-100C... 169.95 TI-5100 DISPLAY 39.95 LCD-PROG NEW 59.95 11-5010 HAND/PRINT 49.95 TI-30II NEW.... 18.95 11-5120 PRINTER . 59.95 TI-35SPSCI . 22.50 FI-5130 PRINT 'DISP 79.95 TMOSCI NEW 28.95 11-5135 PRINT DISP 79.95 BUS ANAL I 19.95 11-5142 PRINT DISP 99.95 BUS ANAL II .. 44.95 TI-58C PROG CALC B9.95 BUS CARD .... 39.95 rl-59 960 PROG 199.95 MBA . .. 54.95 INVEST ANALYST 48.95 PLUG INTO < CONTROL ^~j^^~=-"-^H-!"^ CONTROL LIGH AND APPLIANCES AUTOMATICALLY mum AND INSTANTLY. i TC211TIMER 59.95 TS 555 5 pc TIMER SET NEW 119.95 PK 300 3 pc MINI CONTROLLER 49.95 BBSySTEITI X'tONHI THE SHARP EDGE EL-670 ELECTRONIC PIANO CLOCK. CALCULATOR .. NEW 69.95 CT-665E TALKING CLOCK NEW 99.95 EL-7001 ALPHANUMERIC CALC 139.95 CT-455E POCKET DIG ALARM CLOCK 24.95 EL-5100 PROG ALPHANUMERIC. . . 89.95 EL-6200 ALPHANUMERIC 99.95 EL-1188 HANDHELD PRINT DISPLAY 49.95 EL-1182 DESK TOP PRINTDISPLAY . 74.95 EL-5813 SCIENTIFIC PROGRAMMABLE 34.95 WE WILL MEET OR BEAT ANY COMPETITORS PRICE ON MOST ITEMS IF HE HAS THE -JET CHESS CHALLENGER 7 89.95 #""■ SENSORY CHESS 129.95 MATTEL ■ELiECTP.rjniK I NTELLI VISION 239.95 GAME CARTRIDGES 27.95 HORSERACE ANALYZER 54.95 A TOUCH THE FUTURE ATARI 400 (16K) 294.95 ATARI"' VISICALC AVAILABLE CALL i lYi klilll IDA MP600 CORDLESS HAND- " i I r , "* J "** HELD PHONE 189.95 MERCHANDISE IN STOCK jBTffl NEWPORT BEACH COSTA MESA 1211 S HARBOR HLVD SANTA ANA CA 927(14 (714) 549-7373 WRITE OR CALL FOR FREE CATALOG All units shipped in origina I factory call ons with accessories according lo manufacturer's speci- fication Visa Mastercard. S Order Pers Ck!14 wrkg days to clean COD accepted Mm S4 95 for shipping in U S A Air on regsl CA res add 6% sales tx All mclse subject to availability prices subject to change Send orders to dept WILSHIRE CENTER 3285 WILSHIRE BLVD (213) 385-7777 PASADENA 260 S LAKE AVE (213) 795-3007 BREA 108(1 E IMPERIAL HWY (714) 990-6600 LOS ANGELES 11986 WILSHIRE RLVD (213) 820-0423 TARZANA I8665 VENTURA BLVD (213) 705-7507 TORRANCE LAWNDALE 16611 HAWTHORNE BLVD (213) 370-5795 Professional Discounts Circle 88 on inquiry card. BYTE September 1981 285 back to the left side of the screen, and moved down a notch. It then turns back on and sweeps across the screen again. This process is repeated for 262 sweeps across the screen. (There ac- tually are 525 sweeps across the screen in an alternating system known as interlace. I will ignore in- terlace and act as if the television has only 262 lines.) These 262 lines fill the screen from top to bottom. At the bottom of the screen (after the 262nd line is drawn), the electron beam is turned off and returned to the upper left corner of the screen. Then it starts the cycle over again. This entire cycle happens sixty times a second. Now for some jargon: a single trace of the beam across the screen is called a horizontal scan line. A horizontal scan line is the fundamental unit of measurement of vertical distance on the screen. You state the height of an image by specifying the number of horizontal scan lines it spans. The period during which the beam returns from the right edge to the left edge is called the horizontal blank. The period during which the beam returns from the bottom to the top of the screen is called the vertical blank. The entire process of drawing a screen takes 16,684 /is. The vertical-blank period is about 1400 /is. The horizon- tal blank takes 14 /is, while a single horizontal scan line takes 64 /xs. Most television sets are designed with overscan; they spread the image out so the edges of the picture are off the edge of the television tube. This guarantees that you have no unsight- ly borders in your picture. It is very bad for computers, though, because screen information that is off the edge of the picture does you no good. For this reason, the picture the computer puts out must be somewhat smaller than what the television can theoretically display. For this reason, only 192 horizontal scan lines are normally used by the Atari display. Thus, the normal limit of resolution of a television set used with the Atari 400/800 is 192 pixels (or picture INFOSOFT Has a Better Way l/OS ™ Infosoft/operating system • Full CP/M™, CDOS™, SDOS™, compatibility • Up to 15 disk units of 65 megabytes each • Mix 5" and 8" floppies and hard disks • Autostart and turnkey capabilities • Adaptable to most 8080/8085/Z80 systems • Dialog system generation without programming • Up to 975 megabytes of on-line data storage "New! Developed from the l/OS single-user system' Introducing MULTI/OS™ the complete multi-user operating system All features of the single-user l/OS plus • Up to 16 independent users and/or tasks • Multiple printers with automatic spooling • Up to 56k bytes in each user partition • Managable sub-directories allow up to 63,504 files per unit • Record/file lock capabilities Call Us Today To Improve Your System Performance MASTERCARD and VISA accepted CP/M is a registered trademark of Digital Research, CA CDDS if » reglffered trademark of Cromemco SDOS is a registered trademark of SD Systems ^; cT <*"<•> elements) vertically. (Of course, a color monitor can do much better than that.) The standard unit of horizontal distance is the color clock. You specify the width of an image by stating how many color clocks wide it is. There are 228 color clocks in a single horizontal scan line, with a maximum of 176 actually visible. Thus, the ultimate limit for full color horizontal resolution with a standard color television is 176 pixels. With the computer, you can go even finer and control individual half-clocks. This gives a horizontal resolution or 352 pixels. However, use of this feature produces interesting color effects known as color artifacts. Color ar- tifacts can be a nuisance if they are not desired; they can be a boon to the programmer who desires additional color and is not fazed by their restric- tions. Microcomputer Displays The fundamental problem any microcomputer has in using a raster- scan television for display purposes is that the television display is a dynamic process. Because of this, the television does not remember the im- age. Consequently, the computer must remember the screen image and constantly send a signal to the televi- sion telling it what to display. This process of sending information to the television is a continuous process re- quiring full-time attention. For this reason, most microcomputers have special hardware circuits that handle the television. The basic arrangement is the same on virtually all systems: microprocessor — screen RAM — video hardware — TV screen The microprocessor writes infor- mation to the screen RAM area that holds the screen data. The video hardware is constantly accessing this RAM area, getting screen data and converting them into television signals. These signals go to the televi- sion, which then displays the infor- mation. The screen memory is mapped onto the screen in the same order in which it is stored. That is, the first byte in the screen memory 286 September 1981 © BYTE Publications Inc Circle 166 on inquiry card. Unique accessories to PET/CBM add more power Software PET-FORTH A unique, extensible program- ming language that in many cases has cut program development time to a fraction of the normal. FORTH allows you to program any type of application, thanks to its extensible nature. FORTH programs are modu- lar, structured, extremely fast, and compact. PET-FORTH is a full, ex- tended, standard FORTH, and inclu- des a virtual memory facility, an inter- preter and compiler, a resident editor, as well as a resident macro assembler, all which fits in 8.5K - simultaneously. A comprehensive manual of more than 320 pages, which also is an exhaustive tutorial, is included. For production purposes we can supply a special Target Compiler, that will produce code suitable for placement in ROM, enabling you to write programs for control of digi- tal machines etc. We use FORTH ourselves for business, data base and process control applications. PET-FORTH includes a life-time guarantee. For 8032 only. Price: PET-FORTH, including manual PET-FORTH, only manual Target compiler PET-FORTH $ 390 $ 40 $1000 PET-TERM A program that turns your PET/CBM 8032 into an intelligent terminal. Sup- ports three different interfaces: the PET- COM. the SCIP or the CBM 8010 acoustic coupler. You may communi- cate at up to 9600 baud, with selectable framing and parity. PET-TERM will also translate and transmit Word-Pro files. Data may be printed on the printer or saved on disk PET-TERM includes a life time guarantee. dotflttwiic* P*T- Price: PET-TERM, £ j ng\ including manual s> 1 Oil PET-TERM, a on only manual 3> ^U Dealers are invited. Hardware PET-SWITCH At a sensational price of £ 75 " per unit, PET-SWITCH'enables you to connect up to 16 PET/CBM computers to one disk drive and one printer. You can mix all models of PET/CBM in the same system . (2001,3032, 8032 etc). PET-SWITCH is technically superior to most of its competi tors-no priority problems for example. Price: PET-SWITCH, mother unit PET-SWITCH, daughter unit SCIP A Serial Communication Inter- face that supplies both RS- 232 and Current Loop. Pro- grammable baudrate. Ad- ressed as an IEEE device. 50 character internal buffer. Selectable ASCII translation $250 $150 Price: $480 P ET- CO M - RS-232C interface for PET A bidirectional RS-232C interface that connects to PET via the memory expan sion port. The baud rates range from 50 to 9600, and the number of data bits and stop bits is selectable. You may also set even, odd, or no parity. ^ <£ 1/1E Price: PET IEEE to Centronics Interface This IEEE => Centronics interface is es- pecially constructed for the PET. It is fully addressable and translates from PET- ASCII to Standard ASCII in two different modes, corresponding to PET's graphic and j flj i upper/lowercase modes. This is available r ^*AlB' » through a built-in switch. *Qgl^ia™ Country specific Character Generator for the 4022 and 3022 printers By using this board you can have Greek, French, German, or any other special characters in your printer, at a very low cost It is already used in all Nordic countries, and several other countries have requested it. prjce; $ 4Q '* wi^^^l *W' Datatronic AB is since 1978 sole Swedish distributor of the Commodore computer product line, and is now market leading in microcomputer technology in Scandinavia. Datatronic AB has a long experience in both hardware and software; today Datatronic has used more than 150.000 man-hours in software and hardware development for the PET. All non-Commodore products are produced and tested in-house. The Datatronic-group, which is the fastest growing electronics group in Scandinavia, has a turnover of approximately $ 30.000.000, and employs over 200 people. For further information contact Datatronic AB, Box 42094, S-126 12 Stockholm, Sweden. Phone 8-7445920 or your nearest Commodore dealer. « datatr onic ab ■ ^B Rnv dinod . C-1 Circle 106 on inquiry card. Box 42094 S-126 12 STOCKHOLM Sweden Phone: 8-7445920 Telex: PET S 17828 Circle 239 on inquiry card. MMSFORTH VERSION 2.0: MORE FOR YOUR RADIO SHACK TRS-80 MODEL I OR MODEL III ! • MORE SPEED 10-20 times laster than Level II BASIC. • MORE ROOM Ven/ compact compiled code plus VIRTUAL MEMORY makes your RAM act larger. Variable number ol block buffers. 31-char.-unlque word- names use only 4 bytes In header! • MORE INSTRUCTIONS Add YOUR commands to lis 79-STANDARD-plii3 instruction set! Far more complete than most Forths: single & double precision, arrays, string-handling, clock, more. • MORE EASE Excellent full-screen Editor, structured & modular programming Word search utility THE NOTEPAD letter writer Optimized tor your TRS-80 with keyboard repeats, upper/lower case display driver, full ASCII, single- & double-width graphics, etc. • MORE POWER Forth operating system Interpreter AND compiler 8080 Assembler (Z80 Assembler also available) Intermix 35- to 80-track disk drives Mode! Ill System can read, write & run Model I diskettes! VIRTUAL I/O for video and printer, disk and tape (10-Megabyte hard disk available) FORTH THE PROFESSIONAL FORTH FOR TRS-80 {Over 1,500 systems in use) Prlcii: MMSFORTH Disk System V2.0 (requires 1 disk drive & 16K RAM, 32K for Model III) $129.95* MMSFORTH Cassette System V2.0 (requires Level II BASIC & 16K RAM) $89.95' AND MMS GIVES IT PROFESSIONAL SUPPORT Source code provided MMSFORTH Newsletter Many demo programs aboard MMSFORTH User Groups Inexpensive upgrades to latest version Programming staff can provide advice, modifications and custom programs, to fit YOUR needs. MMSFORTH UTILITIES DISKETTE: includes FLOATING POINT MATH (L.2 BASIC ROM routines plus Complex numbers, Rectangular-Polar coordinate conversions, Degrees mode, more), plus a full Forth-styla Z80 ASSEM- BLER; plus a powerful CROSS-REFERENCER to list Forth words by block and line. All on one diskette (requires MMSFORTH V2.0, 1 drive S 32K RAM) . S39.95* FORTHCOM: communications package provides RS-232 driver, dumb terminal mode, transfer of FORTH blocks, and host mode to operate a remote TRS-80 (requires MMSFORTH V2.0, 1 drlvB & 32K RAM) 139.95* THE DATAHANDLER V1.2: a very sophisticated data- base management system operable by non-pro- grammers {requires MMSFORTH V2.0, 1 drive & 32K RAM) $59.95' MMSFORTH GAMES DISKETTE: real-time graphics & board games w'source code. Includes BREAKFORTH, CRASHFORTH. CRYPTOQUOTE, FREEWAY. OTHELLO & TICTACFORTH (requires MMSFORTH V2.0. 1 drive & 32K RAM) $39.95* Other MMSFORTH products under development FORTH BOOKS AVAILABLE MMSFORTH USERS MANUAL - w/o Appendices, for non- owners $15.00* USING FORTH ■ more detailed and advanced than above $25.00* INVITATION TO FORTH ■ detailed beginner book on flgFORTH $17.50* THREADED INTERPRETIVE LANGUAGES - advanced, excellent analysis of MMSFORTH-IIke lan- guage $18.95* PROGRAM DESIGN & CONSTRUCTION - Intro, to struc- tured program, good for Forth $8.95* FORTH -79 STANDARD MANUAL ■ official reference to 79-STANDARD word set, etc $10.00* CALTECH FORTH MANUAL - good on Forth Internal structure, etc $10.00* FORTH SPECIAL ISSUE. BYTE Magazine (Aug. 1980) -we stock this collector's Item for Forth users and beginners $4.00* ' - ORDERING INFORMATION: Software prices Include manuals and require signing of a single system, single- user license. SPECIFY for Model I or Model III! Add $2.00 S/H plus $3.00 per MMSFORTH and $1.00 per addi- tional book; Mass. orders add 5% tax. Foreign orders add 20%. UPS COD, VISA & M/C accepted; no unpaid purchase orders, please. Send SASE for free MMSFORTH information. Good dealers sought Get MMSFORTH products from your computer dealer or MILLER MICROCOMPUTER SERVICES (B9) 61 Lake Shore Road, Natick, MA 01760 (617)653-6136 maps to the top left corner of the screen, the second byte maps one position to the right, then the third, the fourth, and so on to the last byte that is mapped to the lower right cor- ner of the screen. The quality of the image that gets to the screen depends on two factors: how sophisticated the video hard- ware is, and how much screen memory is used. The simplest ar- rangement is used by the Radio Shack TRS-80 and the Commodore PET. These machines allocate a specific 1 K bytes of RAM as screen memory. The video-hardware circuits simply pull data out of this area, interpret them as characters (using a character set in ROM), and put the resulting characters on the screen. Each byte represents one character, allowing a choice of 256 different characters in the character set. With 1 K bytes of screen RAM, 1024 characters can be displayed on the screen. There isn't much that can be done to modify this arrangement. The Apple II, from Apple Com- puter Inc, uses more advanced video hardware. Three graphics modes are provided: text, low-resolution (lo-res) graphics, and high-resolution (hi-res) graphics. The text graphics mode operates much as the PET and TRS-80 displays operate. In the low- resolution graphics mode, the video hardware reaches into screen memory and interprets it differently. Instead of interpreting each byte as a character, each byte is interpreted as two blocks of color. The value of each block (4 bits) specifies the color of a single pixel. In the high- resolution graphics mode, each bit in screen memory is mapped to a single pixel. If the bit is on, the pixel gets color in it; if the bit is off, the pixel stays dark. The situation is com- plicated by a variety of design nuances in the Apple, but that is the basic idea. The important point is that the Ap- ple has three display modes — three completely different ways of inter- preting the data in screen memory. The Apple video hardware is in- telligent enough to interpret a screen- memory byte as either an 8-bit character (text mode), two 4-bit color nybbles (low-resolution mode), or 7 individual bits for a bit map (high- resolution mode). Atari 400/800 Display List The Atari 400/800 display-list system represents a generalization of these systems. Where the PET and TRS-80 have one mode and the Apple has three modes, the Atari 400/800 has fourteen modes. A second impor- tant difference is that Atari 400/800 display modes can be mixed on the screen. You are not restricted to a choice between a screen full of text or a screen full of graphics. Any collec- tion of the fourteen Atari graphics modes can be displayed on the screen simultaneously. The third important difference is that the Atari 400/800 screen RAM can be located anywhere in the address space of the computer and moved around while the program is running, whereas the other machines use fixed-screen memory areas. This generality is made possible by a video microprocessor called AN- TIC. Where earlier systems used rather simple video circuitry, Atari designed a full-scale microprocessor just to handle the intricacies of the television display. ANTIC is a true microprocessor — it has an instruction set, a program, and data. The pro- gram for ANTIC is called the display list. The display list specifies three things: where the screen data can be found, what display modes to use to interpret the screen data, and what special display options (if any) should be implemented. When using the display list, it is im- portant to shed the old view of a screen as a homogeneous image in a single mode and see it instead as a stack of mode lines. A mode line is a collection of horizontal scan lines. It stretches horizontally all the way across the screen. An Atari graphics 2 mode line is 16 horizontal scan lines high, while a graphics 7 mode line is only 2 scan lines high. Many graphics modes available from BASIC are homogeneous; an entire screen of a single mode is set up. But you must not limit your imagination to this pat- Everybody's making money selling microcomputers. Somebody's going to make money servicing them* New NRI Home-Study Course Shows You How to Make Money Servicing, Repairing, and Programming Personal and Small Business Computers Seems like every time you turn around, some- body comes along with a new computer for home or business use. And what's made it all possible is the amazing microprocessor, the tiny little chip that's a computer in itself. Using this new technology, the industry is offering compact, affordable computers that handle things like payrolls, billing, inventory, and other jobs for businesses of every size... perform household functions including budgeting, environmental sys- tems control, indexing recipes. And thousands of hobbyists are already owners, experiment- ing and developing their own programs. Growing Demand for Computer Technicians This is only one of the growth factors influenc- ing the increasing opportunities for qualified com- puter technicians. The U.S. Department of Labor projects over 100% increase in job openings for the decade through 1985. Most of them new jobs created by the expanding world of the computer. Learn at Home in Your Spare Time NRI can train you for this exciting, rewarding field. Train you at home to service not only mi- crocomputers, but word processors and data termi- nals, too. 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Then you use the lab and meter to actually access the interior of your computer. .. build special circuits and writeprograms to control them. You "see" your computer at work and demonstrate its power. Become the Complete Computer Person You're also trained in writing and debugging both BASIC and advanced machine language pro- grams... gain hands-on experience in the operation and application of computers to business and personal jobs. You're trained to become the fully rounded, new breed of technician who can interface with the operational, program- ming, and service facets of today's computers. You' re ready to take your place in the new electronic age. Other Opportunities NRI has been giving ambitious people new electronic skills since 1914. Today's offerings also include TV/ Audio/Video Systems servicing with training on our exclusive computer-programmable 25" diagonal color TV. .. Communications Elec- tronics for servicing and installing microwave, broadcast, CB, radar, etc... and other state-of-the- art courses. Free Catalog . . . Mail Card No Salesman Will Call Send the postage-paid card for our 100-page catalog showing all courses with equipment and complete lesson plans. There's no obligation other than to yourself. See how NRI can help you grow with the most exciting and important new field of the 80's. If card has been removed, please write to us. i NRI SCHOOLS McGraw-Hill Continuing Education Center C-"i • TT7 3939 Wisconsin Ave. iTH I M Washington, DC 20016 I fl'lli Washington, We'll give you tomorrow. BYTE September 1981 289 Value of Bit Pair Binary Decimal 00 01 10 11 Atari Color Register Used COLBAK COLPF0 COLPF1 COLPF2 Table 1: Atari color-register assign- ment in four-color map mode. tern; with the display list, you can create any sequence of mode lines down the screen. The display list is a collection of code bytes that specify that sequence. ANTIC's Instruction Set ANTIC's instruction set is rather simple. There are four classes of in- structions: map-mode instructions, character-mode instructions, blank- line instructions, and jump instruc- tions. Map-mode instructions cause ANTIC to display a mode line with simple colored pixels (no characters). Character-mode instructions cause ANTIC to display a mode line with characters in it. Blank-line instruc- hitnxluciiig AUTO-CAT It gets you off the hook. Auto-Cat™ lets your computer terminal answer other terminals over the phone line automatically. It's the deluxe way, for example, to receive a program from a friendly computer. Or take data from any of the information sources. Then store the informa- tion in your computer's memory — and have it there at your beck and call — all automatically. Auto-Cat is a state-of-the-art originate/auto answer, all digital, crystal controlled unit with every- thing in one compact package. It sits right under your phone. It's FCC approved for direct telephone line connection. You just take it home and plug it in. Cost? Less than any other comparable modem. Under $250. And it's from Novation. The recognized leader in personal communications. Auto-Cat by Novation Call for details: (800) 423-5410 In California (213) 996-5060 Available at Avnet Electronics, Hamilton Electro, Hamilton Avnet, Kierulff Electronics, Byte Shops, Computerland, and your local computer store. Novation, Inc., 18664 Oxnard Street, Tarzana, California 91356 tions cause ANTIC to display a number of horizontal scan lines with a solid background color. Jump in- structions are analogous to a 6502 IMP instruction; they reload ANTIC's program counter with a new value. There are also four special options that can sometimes be specified by setting a designated bit in the ANTIC instruction. These op- tions are: display-list interrupt (DLI), load-memory scan (LMS), vertical scroll, and horizontal scroll. Map-mode instructions cause AN- TIC to display a mode line containing pixels with solid color in them. The color that is displayed comes from a color register. The choice of color register is specified by the value of the screen data. In four-color map modes (BASIC modes 3, 5, and 7, and AN- TIC modes hexadecimal 8, A, D, and E), a pair of bits is required to specify a color register; these values are given in table 1. [Unfortunately, the graphics mode numbers in BASIC do not correspond to the mode numbers used by ANTIC; this often causes confusion. .. ,GW] Since only 2 bits are needed to specify one pixel, four pixels are en- coded in each screen-data byte. For example, a byte of screen data con- taining the hexadecimal value IB would display four pixels; the first would be the background, the second would be color register 0, the third would be color register 1, and the fourth would be color register 2: hexadecimal IB = binary 00011011 = 00 01 10 11 In two-color map modes (BASIC modes 4, 6, and 8, and ANTIC modes hexadecimal 9, B, C, and F), each bit specifies one of two color registers. A bit value of selects background col- or for the pixel; a bit value of 1 selects color register for the pixel. Eight pixels can be stored in one screen- data byte. There are eight different map- display modes. They differ in the number of colors they display (two colors versus four colors), the vertical size one mode line occupies (1, 2, 4, 290 September 1981 © BYTE Publications Inc Circle 259 on inquiry card. Circle 68 on inquiry card. CompuServe is a lot more than fan and games and news. Although we're probably best known for our consumer-oriented services, CompuServe maintains powerful services for the serious computer user. CompuServe has helped some of the nation's largest companies and financial institu- tions through a wide range of business and scientific-oriented computer programs. With our Information Service, we can extend this expertise to you. Here are some of the programs available to the personal computer user through the CompuServe Information Service: PASCAL: DEC User Group version of this famous language. XF4: Extended CompuServe Fortran compiler. MACRO: Advanced Macro Assembly language for PDP-10. Talk about fast. FILGE: Fast, easy file generator and editor. Line oriented, no line numbers required! XBASIC: CompuServe extended BASIC. JUMBLE: File encryption program. TECO: High level text editor. LINK: Linking loader program. DDT: Dynamic debugging tool. CREF: Symbolic cross-reference generator used with language compilers. FILCOM: File comparison program. SALARY: Calculates salary and increases in various time frames including per year, month, period and hour. This program is intended primarily for managers doing reviews. SNOBOL: String manipulation language. RUNFIO: Word processing and text formatting program (write resumes etc.). CONCOR: Concordance generator. This program is very useful for documentation purposes. CONCOR reads an ASCII file and creates an output file which con- tains a line numbered listing of the original file, and a list of all the words contained in the file along with the numbers of the lines on which each word occurs (similar to an index). BLIS1 0: High level implemen- tation language for DEC PDP-10. BINED: Binary file editor. APL: A Programming Language. FINTOL: Financial analysis tool. Contains several program modules which can perform financial analy- sis for business or personal needs. — Loan Payment and Amortization — Compound Interest Calculations — Sum from a Periodic Investment — Sinking Fund Deposit — Present Value of Cash Flows — Present Value and Internal Rate of Return (Capital Projects) — Depreciation Analysis — Compound Growth Rates RANNO: Random number generator. XEDIT: XF4 binary file editor. We also offer high speed professional line printer service, error-free file transfer, CompuServe's Software Exchange, and computer manufacturers' newsletters. Computer Users Groups can exchange information and up-to-the-minute gossip in the computer world. And ... if Aunt Matilda comes over, you can still let her play Adventure. Demonstrations and software at all Radio Shack® Computer Centers and many Radio Shack® outlets. CompuServe Information Service Division 5000 Arlington Centre Boulevard Columbus, Ohio 43220 (614)457-8600 Radio Shack is a trademark of Tandy Corporation. ANTIC BASIC Number of Scan Lines Per Pixels Per Bytes Per Bytes Per Mode Mode Colors Mode Line ModeL me Line Screen 2 2 8 40 40 960 3 none 2 10 40 40 760 4 none 4 8 40 40 960 5 none 4 16 40 40 480 6 1 5 8 20 20 480 7 2 5 16 20 20 240 8 3 4 8 40 10 240 9 4 2 4 80 10 480 A 5 4 4 80 20 960 B 6 2 2 160 20 1920 C none 2 1 160 20 3840 D 7 4 2 160 40 3840 E none 4 1 160 40 7680 F 8 2 1 320 40 7680 Table 2: Atari graphics modes and their characteristics. Note that the same graphics mode is given a different number by BASIC and by ANTIC. The ANTIC mode number refers to one mode line o/ a groen foW of graphics, while the BASIC mode number refers to a certain arrangement of mode lines (most or all of u, hich are the given kind of graphics) that defines an entire screen of video display. or 8 scan lines), and the number of pixels that fit horizontally into one mode line (40, 80, 160, or 320). Thus, some map modes give better resolu- tion; these will require more screen memory. Table 2 presents this infor- mation for all modes. Character-mode instructions cause ANTIC to display a mode line with characters in it. Each byte in screen RAM specifies one character. There are six character-display modes. Character displays will be discussed in a future BYTE article in this series. Blank-line instructions produce "blank" lines consisting of only a solid background color. There are eight blank-line instructions; they specify skipping one through eight blank lines. There are two jump instructions. The first (JMP) is a direct jump; it reloads ANTIC's program counter with a new address that follows the JMP instruction as an operand. Its only function is to provide a solution to a tricky problem. ANTIC's pro- gram counter is only 10 bits wide. Thus, it cannot cross a 1 K-byte boundary. If the display list must cross a 1 K-byte boundary, it must use a JMP instruction to hop over the boundary. This means that display lists are not fully relocatable. The second jump instruction (JVB) is more commonly used. It reloads the program counter with the value in the operand and waits for the televi- sion to perform a vertical blank. This instruction is normally used to end a display list by jumping to the top of the display list. Jumping to the top turns it into an infinite loop; ANTIC waits for vertical blank to insure that the infinite loop is synchronized to the display cycle of the television. Both JMP and JVB are 3-byte instruc- tions; the first byte is the operation code (JMP or JVB), the second and third bytes are the address to jump to (low byte, then high byte). The four special options mentioned previously will be discussed in future articles in this series. However, the load-memory scan option must have a preliminary explanation. This op- tion is selected by setting bit 6 of a map-mode or a character-mode in- struction byte. When ANTIC en- counters such an instruction, it will load its memory-scan counter with the two following bytes. This memory-scan counter tells ANTIC where the screen memory is, and AN- TIC begins fetching display data from this area. The LMS instruction is a 3-byte instruction: a 1-byte operation code followed by 2 bytes of operand. In simple display lists, the LMS in- MICROPROCESSOR INTERFACE ■ 1— BCD (4 LINES) - L DATA READY — .BCD DATA (4 LINES) - -DIGIT STROBE ■DECIMAL POINT 128 POINT SW- MATRIX (32 BCD SW s @ 4 BITS EACH) BCD DATA (6 LINES) 1 ' MATRIX ROW STROBE (16 LINES). CPU RESET PROC READY (PROVIDES SYSTEM TURN ON) Weigh Systems Technology, Inc. 5701 ATLANTIC BLVD. MAYWOOD, CALIF. 90270 213/582-0701 2896 SOUTHWAY MEMPHIS. TENN 38118 901/363-1521 CPU KEEP ALIVE PC-114-1-Single board CPU status sensor which provides high power PROC READY (system enable) and CPU RESET signals. S114.00ea. 128 POINT MATRIX CONTACT RECEIVER PC-101-1- Single board switch — computer interface which, under software control, selects and receives mechanical switch data with switch selectable addressing. $194.00ea. 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Most items shipped U.P.S. 292 September 1981 © BYTE Publications Inc Circle 382 on inquiry card. if He'd used select it wouldn't have taken seven days Learn SELECT in just 90 minutes. A whole new word processing software concept that kicks the coded key habit and frees you from complicated instruction manuals. SELECT is fast. SELECT is logical. With single key mnemonics, you'll use dozens of commands that instantly access the rich capabilities of this system. There's nothing like it. Simply hit "C" and you'll be ready to Create a document. Key "I" and you'll be in the Insert mode. Key "M" and Move entire blocks of text . . . and key dozens more. That's all there is to it. You'll get all that word processing software promises . . . plus a few surprises. SELECT 'with SUPERSPELL .* The only microcomputer software with an integrated spelling dictionary. To proof your text all you do, of course, is to key "S". SUPERSPELL with its 10,000 word dictionary scans your text at computer speed then displays and corrects all your typing errors. You can increase SUPERSPELL's word power and customize the dictionary by adding new words, one at a time. Ask to see it today at your local dealer. SELECT with SUPERSPELI just a little byte more. ect SELECT will run on any machine that uses CP/M or MP/M" or its derivatives. It needs 40K of RAM and two disk drives. Special version now available for Radio Shack Mod IP*' and Apple II**** ' SELECT and SUPERSPELL are trademarks of Select Information Systems Inc. •* CP'M and MP/M are trademarks ol Digital Research ■ * * A trademark ol Tandy Corp. "** A trademark of Apple Computer Inc. INFORMATION SYSTEMS 919 Sir Francis Drake Boulevard ■ Kentfield, California 94904 -(415) 459-4003 Circle 327 on inquiry card. BYTE September 1981 293 Circle 87 on inquiry card. 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AMPEX Dialogue 80"" Dialogue 80™ fully-featured video terminal: • Full ASCII with numeric and edit keypads • Elegant case with detachable keyboard • Display 24 lines with 25th status line • 20 user programmable function keys - 2 pages display memory (4 optional) 1 1 graphics and 21 control codes 10 modes including block, protect, program Transparent mode displays control codes Dialogue 80™ $1045 Dialogue 80™ with phone coupler 1194 Applications: word processing, data entry, interac- tive programming, data base inquiry/response/ update, transaction processing, whether on-site or remote. For our system or for yours, this inter- active terminal is the perfect match. Prices: Prepaid or Purchase Order Net 10. Prices subject to change without notice. Warranty: 120 day minimum on all systems. Interfacing cables free with all systems. 10% down fixes price, guarantees priority. MasterCard and VISA cards accepted. (312) 684-3183 W™ COMPUTEX ^^. \ MICROCOMPUTER SYSTEMS \ \ \ 5710 Drexel, Chicago, IL 60637 struction is used only once, at the beginning of the display list. It may sometimes be necessary to use a sec- ond LMS instruction. The need arises when the screen-memory area crosses a 4 K-byte boundary. (The memory- scan counter is only 12 bits wide, which is why it cannot cross a 4 K boundary.) In this case, an LMS in- struction must be used to jump the memory-scan counter over the boundary. This means that display data are not fully relocatable. LMS instructions have wider uses that will be discussed later in this series. Building Display Lists Every display list should begin with three "blank-eight-lines" instructions. This defeats vertical overscan by bringing the beginning of the useful display 24 scan lines down. After this is done, the first display line should be specified. Simultaneously, the LMS should be used to tell ANTIC where it will find the screen memory. Then follows the actual display list, which lists the display bytes for the mode lines on the screen. The total number of horizontal scan lines pro- duced by the display list should always be 192 or less; ANTIC does not maintain the screen-timing re- quirements of the television. If you give ANTIC too many scan lines to display, it will do so, but the televi- sion screen will probably roll. Displaying fewer than 192 scan lines causes no problems; indeed, it decreases 6502 execution time by reducing the number of cycles stolen by ANTIC. The programmer must calculate the sum of the horizontal scan lines produced by his or her display list and verify it. The display list must end with a JVB instruction. A typical display list for a standard BASIC graphics mode display (all values are in hexadecimal) is given in table 3. As you can see, this display list is short — only 32 bytes. Most display lists are less than 100 bytes long. Furthermore, they are quite simple in structure and easy to set up. To implement your own display list, you must first design the display Hexadecimal Hexadecimal Address Value Meaning 7BE0 70 blank 8 lines 70 blank 8 lines 70 blank 8 lines 42 display ANTIC mode 2 (BASIC mode 0) 20 also, screen memory starts at 7C20 7C 02 display one mode line of ANTIC mode 2 02 02 02 02 02 02 02 02 02 02 02 02 02 02 02 02 02 02 02 02 02 02 41 JVB instruction — wait for the vertical- E0 blank signal, then jump to the beginning 7B of the display list, which starts at $7BE0 Table 3: The display list for i i standard BASIC graphics mode display. 294 September 1981 © BYTE Publications Inc NEECO WHY BUY FROM THE BEST? Service.. . Support... Software . . . Cf commodore MULTI-CLUSTER For Commodore Systems, allows 3 CPU's (Expandable to 8) to access a single Commodore Disk. MULTI-CLUSTER (3 CPU's) S 795 Each Additional CPU (up to 8) . . . S 199 16K B (16K RAM-40 Column) - Lim. 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Keep track of the scan-line count of your display by looking up the scan-line requirements of the various modes in table 2. Translate the sequence of mode lines into a se- quence of ANTIC mode bytes. Put 3 "blank-eight-lines" bytes (hexa- decimal 70) at the top of the list. Set bit 6 of the first display byte (that is, make the upper nybble a 4) — this makes it a load-memory scan com- mand. Follow with 2 bytes that specify the address of the screen RAM (low byte, then high). Then follow this with the rest of the display bytes. At the end of your display list, put in the JVB instruction (hexadecimal 41) and the address of the top of the display list. Store all these bytes into memory. They can be anywhere you want; just make sure they don't overlie something else, and be sure your JVB instruction at the end of the display list points to the top of the display list. The display list must not cross a 1 K-byte address boundary. If you absolutely must have it cross such a boundary, insert/ a JMP instruction just in front of the boundary, with the JMP instruction's operand being the address of the first byte on the other side of the boundary. Next, you must turn off ANTIC for a fraction of a second while you rewrite its display- list pointer. Do this by writing a in- to hexadecimal location 22F (known as SDMCTL). Then store the address of the new display list into hexa- decimal locations 230 and 231 (low byte, then high). Lastly, turn ANTIC back on by depositing a hexadecimal 22 into SDMCTL. During the vertical blank, while ANTIC is quiet, the operating system will reload ANTIC's program counter with these new values. Screen-Data Placement Screen memory can be placed anywhere in the address space of the computer. Normally, the display list specifies the beginning of the screen memory with the first display instruc- tion — the initial LMS instruction. However, ANTIC can execute a new LMS instruction with each display line of the display list, if this is desired. In this way, information from all over the address space of the computer can be displayed on a single screen. This can be of value in setting up independent text windows. There are several restrictions in your placement of the screen memory. First, screen memory should not cross a 4 K-byte address boundary. If you cannot avoid cross- ing a 4 K-byte boundary (as would be the case in BASIC mode 8, which uses 8 K bytes of RAM), you must reload the memory-scan counter with a new LMS instruction. Second, if you wish to use any of the Atari Screen memory can be placed anywhere In the address space of the computer. operating-system screen routines, you must abide by the conventions the operating system uses. This can be particularly difficult when using a modified display list in a BASIC pro- gram. If you alter a standard display list from a BASIC program and then attempt to PRINT or PLOT to the screen, the operating system will do so under the assumption that the display list is unchanged. This will probably result in a garbled display. There are three ways the display can fail when you attempt this. First, BASIC may refuse to carry out a screen operation because it is impossi- ble to do with the graphics mode that the operating system thinks it is in. The operating system stores the value of the graphics mode that it thinks is on the screen in hexadecimal address 57. You can fool the operating system into cooperating by POKEing a dif- ferent BASIC mode value there. POKE the BASIC mode number, not the ANTIC mode number. The second failure arises when you mix mode lines with different screen- memory byte requirements. Some mode lines require 40 bytes per line, some require 20 bytes per line, and some require only 10 bytes per line. Let's say that you insert one 20-byte mode line into a display list with 40-byte mode lines. Then you PRINT text to the display. Everything above the interloper line is fine, but below it the characters are shifted twenty spaces to the right. This is because the operating system assumed that each line would require 40 bytes and posi- tioned the characters accordingly. But ANTIC, when it encountered the interloper line, took only 20 bytes of what the operating system thought should be a 40-byte line. ANTIC in- terpreted the other 20 bytes as belonging to the next line and displayed them there. This resulted in the next line and all later lines being shifted twenty spaces to the right. The only absolute way around this problem is to refrain from using BASIC PRINT and PLOT statements to output to a mixed display-list screen. The quick and dirty solution is to organize the screen into line groups that contain integer multiples of the standard byte requirement. That is, do not insert a 20-byte mode line into a 40-byte display; instead, insert two 20-byte lines or one 20-byte line and two 10-byte lines. As long as you retain the proper integer multiples, the horizontal shift will be avoided. This solution accentuates the third problem with mixed display lists and BASIC: vertical shifts. The operating system positions screen material ver- tically by calculating the number of bytes to skip down from the top of the screen. In a standard 40-byte line display, BASIC would position the characters onto the tenth line by skip- ping 360 bytes (40 bytes per line times 9 full lines) from the beginning. If you have inserted four 10-byte lines, BASIC ends up 3 lines further down the screen than you would otherwise expect. Furthermore, different mode lines consume different numbers of scan lines, so the position on the screen will not be quite what you ex- pected if you do not take scan-line costs into account. As you can see, mixed-mode displays can be difficult to use in con- junction with the operating system. Often, you must fool the operating system to make such displays work. 296 September 1981 © BYTE Publications Inc $3398 10MB HARD DISK YOU'VE BEEN WAITING FOR XCOMP introduces a complete micro-size disk subsystem with more... • MORE STORAGE • MORE SPEED • MORE VALUE • MORE SUPPORT S100 users . . . The XCOMP subsystem is now available with 1 megabytes of storage; 5 megabytes also available at $2,898.00. Compare the price and features of any other 5% -inch — or even 8 -inch system, and you'll agree that XCOMP's value is unbeatable. OUTPERFORMS OTHER HARD DISKS Floppy disk and larger, more expensive hard disks are no match for this powerful little system. More data is available on every seek: 64K on 1 0MB and 32K on 5MB. Faster seek time too — an average of 70MS. It provides solid performance anywhere with only 20 watts of power. Data is protected in the sealed enclosure, and the landing zone for heads provides another margin of safety. The optional power board plugs directly into the S100 bus and provides power for the drive. FAST CONTROLLER The XCOMP controller is the key to this system's high efficiency operation. Speed-up features include interleave without table lookup, block- deblock with controller buffer, and read lookahead. OEMs world wide have already proven the outstanding perfor mance of the XCOMP controller. rorld- ^^ MORE SOFTWARE Included with the system is software for testing, for- matting, I/O drivers for CP/M® , plus an automatic CP/M driver attach program. Support software and drivers for MP/M® and Oasis® are also available. The sophisticated formatting program assigns alternate sectors for any weak sectors detected during format- ting, assuring the lowest possible error rate — at least ten times better than floppies. WARRANTY The system has a full one-year warranty on parts and workmanship. ALSO AVAILABLE FROM XCOMP • General Purpose controllers (8 bit interface), with easy interface to microprocessor- based systems. • GP controller adapter that plugs directly into most Z80 computers. • ST/R GP controller for the 5MB and 1 0MB drive above, with ST506 type interface. • SG/R GP controller for SA1 000 interface. • SM/R GP controller for storage module drives. • ST/S, SG/S, and SM/S, same as above, for the S100 bus. Quantity discounts available. Distributor, Dealer, and OEM inquiries invited. See your local Dealer, or call: XCOMP XCOMP, Inc. 7566 Trade Street San Diego, CA 92121 Tel: (714) 271-8730 Telex: 182786 Circle 388 on Inquiry card. Circle 95 on inquiry card. Buy Direct from v* H I ^% An Authorized Direct HP Dealer HUGE SAVINGS ON CALCULATORS AND COMPUTERS Call 800-682-9250 in California • 800-538-9580 all other states including Alaska and Hawaii 408-624-0822 outside USA • Telex 172532 • TWX 9103605000 Hours 7:00-6:00 (PST) Monday-Friday Eel HEWLETT PACKARD COMPUTERS HP-85 Built In Printer/Tape SYS/CRT 2600.00 HP-83 Built In CRT 1800.00 HP 7225B Plotter 1960.00 HP 2631B OPT 885 Printer 3160.00 5Vi Dual Master Flex Drive 2000.00 5% Single Master Flex Drive 1200.00 8" Dual Master Flex Drive Call 8" Single Master Flex Drive Call 16K Memory 236.00 PERIPHERALS & SOFTWARE VisiCalcTM PLUS 170.00 Graphic Presentations 170.00 Surveying 170.00 Basic Training 80.00 Financial Decisions 80.00 -^CQ HP-41C SOFTWARE CALCULATORS Financial Decisions 27.00 HP-32E ADV SCI W/STAT 44.00 Securities 27.00 HP-33C PROG SCI 72.00 Statistics 27.00 HP-34C ADV PROG SCI 120.00 Home Management 27.00 HP-37E BUSINESS 60.00 Real Estate 40.00 HP-38C ADV FIN 120.00 HP-41C ALPHANUMERIC FULL PERFORMANCE 200.00 OTHER PRODUCTS HP-41CV ALPHANUMERIC FULL Epson Printers MX- 80 Call PERFORMANCE QUAD MEM 265.00 . M i„»*U . PRINTER CARD READER 308.00 172.00 QUAD MEMORY 76.00 ^5?* Maxell Diskettes Call Prices subject to change without notice • Prices do not reflect shipping and handling charges CPI — P.O. Box 22530 — Carmel, CA 93922 • 3785 Via Nona Marie Call for items not shown in this ad To PRINT or PLOT to a mode win- dow, POKE the BASIC mode number of that window to hexadecimal loca- tion 57, then POKE the address of the top left pixel of the mode window into hexadecimal locations 58 and 59 (low byte, then high). In character modes, execute a POSITION 0,0 to home the cursor to the top left corner of the mode window. In map modes, all PLOTs and DRAWTOs will be made using the top left corner of the mode window as the origin of the coordinate system. The display-list system can be used to produce appealing screen displays. Its most obvious use is for mixing text and graphics. For example, you could prepare a screen with a bold BASIC mode 2 title, a medium-size BASIC mode 1 subtitle, and small BASIC mode fine print. You could then have a BASIC mode 8 picture in the middle, with more text at the bottom. With assembly-language routines, modified display lists are best used by organizing the screen into a series of windows, each window having its own LMS instruction and its own in- dependent RAM area. Modification Applications One simple application of display- list modifications is to vertically space lines on the screen by inserting blank-line bytes. This will add some vertical spacing, which will highlight critical messages and enhance the readability of some displays. Another important use of display- list modifications is in providing ac- cess to features not available from BASIC. There are three text modes supported by ANTIC that BASIC does not support. You can gain access to these modes only by modifying the display list. There are also display- list-interrupt and fine-scrolling capabilities that are only available after the display list is modified. These features are the subjects of later articles in this series. Manipulations with the LMS in- struction and its operand offer many possibilities to the creative program- mer. For example, by changing the LMS during vertical blank, the pro- grammer can alternate screen images. 298 September 1981 © BYTE Publications Inc . . .And my dad says GRAFTRAX80 does better graphics than anybody. Epson. You might say it's the head of its class. GRAFTRAX 80 gives you the highest resolution dot matrix in the world — up to 120 dots per inch horizontally and 216 dots per inch vertically. Which makes our MX-80 and MX-80 F/T work more like a plotter than a printer. And that's just for starters. GRAFTRAX 80 more than doubles the features avail- able in an Epson MX-80 or MX-80 F/T. For instance, we've added nice little touches like an italic character set — which doubles the number of font types to 24. And with GRAFTRAX 80, you can change style, size and density anywhere in the line. And backspace the head. And use block graphics with any computer. And redefine all escape codes under software control. Up to now, you couldn't get some of these features at any price. With GRAFTRAX 80, you get 'em all. And more. Lots more. Best of all, we haven't forgotten all those people who already own an MX-80 or MX-80 F/T. You own the printer that set the standards all the others are follow- ing. And you can install GRAFTRAX 80 PROMs your- self, for less than $100. And make the best even better. You can see why we say GRAFTRAX 80 is the head of its class. There's nothing else in its class. EPSON EPSON AMERICA, INC. 3415 Kashiwa Street • Torrance, California 90505 • (213) 539-9140 Circle 141 on Inquiry card. BYTE September 1981 299 Pi first frame 1 second frame B third frame B fourth frame B effective luminance x 4 2 perceived luminance Table 4: Advanced color and I the video display; see the text xel C 1 1 B B 4 ontents (By Color 112 3 1 1 B B 1 1 B B B 1 B B 6 8 10 12 Register) 2 3 2 2 3 2 B B 2 B B B 20 24 30 3 2 3 3 2 3 3 2 3 B 2 3 36 40 48 iminance control through the high-speed changing of for details. This can be done at slow speed to change between predrawn displays without having to redraw each one. Each display would continue to reside in (and consume) memory even while it is not in use, but it would be available almost instantly. This technique can also be used for anima- tion. By flipping through a sequence of displays, cyclic animation can be achieved. The program to do this would manipulate only 2 address bytes to display thousands of bytes of memory. It is also possible to superimpose images by flipping screens at high speed. The human eye has a time resolution of about y 16 of a second, so a program can cycle between four images, one every V 60 of a second, so each repeats every y H of a sec- ond. In this way, up to four images can appear to reside simultaneously on the screen. There are some drawbacks to this method. First, four separate displays may well cost a lot of memory. Second, each display im- age will be washed out because it only shows up one quarter of the time. This means that the background of all displays must be black, and each im- age must be bright. Furthermore, there will be some unpleasant screen flicker when this technique is used. A conservative programmer might con- sider cycling between only three or Need a Real-Time Multi-Tasking Executive for 8080 and Z80? • Faultless operation proven in world wide use • Truly hardware independent • Optimized for fast interrupt response • Minimal memory requirements • ROMable for control applications • Terminal Handler is CP/M BDOS compatible • Console Driver supports Intel iSBC boards • SYSGEN speeds user system configuring • Program in PL/M, Fortran, Pascal or Assembler • Source code included (Intel or Zilog mnemonics) • Unlimited use licence agreement • Complete documentation (available separately) • Low cost Jt KADAK Products Ltd. 206-1847 West Broadway Avenue Vancouver, B.C., Canada V6J 1Y5 Dealer enquiries invited Telephone (604) 734-2796 CP/M is .1 trademark of Digital Research Corp.; RMX/80, iSBC are trademarks ol Intel Corp. even two images. This technique can also be used to extend the color and luminance resolution of the com- puter. By cycling between four ver- sions of the same image, each version stressing one color or luminance range, a wider range of colors and luminosities is available. For example, suppose we wish to display a bar of many different luminances. We first set our four col- or registers to the following hexa- decimal values: background: 00 playfield 1: 02 playfield 2: 0A playfield 3: 0C If we put the images described in table 4 into each of the screen-memory areas, we can achieve much finer luminance resolution. A final suggestion concerns a sub- ject that is laden with opportunities, but that is as little understood as the dynamic display list. This is a display list that the 6502 changes dur- ing vertical-blank periods. It should be possible to produce interesting ef- fects with dynamic display lists. For example, a text-editing program could dynamically insert blank lines above and below the screen line being edited to set it apart from the other lines of text. As the cursor is moved vertically, the display list is changed to isolate the screen line the cursor is on. The technique is odd but very ef- fective. Conclusions The display list is a powerful system for creating and controlling displays. It is not a simple system. In essence, it is a scheme for mating two completely different technologies, the television and the microcomputer. When I consider the differences be- tween these two technologies and the exacting demands of each, I am sur- prised that the display-list system achieves such a favorable combina- tion of power and simplicity. Even more surprising is the way the display-list system supports an even more powerful set of graphics capabilities, such as graphics indirec- tion, display-list interrupts, and fine scrolling. These will be the subjects of future articles in this series. ■ 300 September 1981 © BYTE Publications Inc Circle 183 on Inquiry card. 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Natural-Language Processing The Field in Perspective Gary G Hendrix Natural Language Program Aritificial Intelligence Center SRI International 333 Ravenswood Ave Menlo Park CA 94025 Earl D Sacerdoti Machine Intelligence Corp 1120 San Antonio Rd Palo Alto CA 94303 Through a process spanning thousands of years, natural languages have evolved to meet the manifold needs of people to communicate and record a diversity of information in a wide variety of circumstances. Natural language is the medium of the butcher, the baker, and the candlestick maker; the poet and the lover; the politician and the preacher; the parent and the child. Even for the scientist and computer programmer, it is the mother tongue — the language resorted to when formal expres- sions and intuition fail. Natural languages stand in marked contrast to formal languages, such as BASIC and Pascal, which were de- signed to be easily understood by computers and are intended for the specialized task of expressing algorithms and data structures. The fluent use of natural language is an information-processing activity of great complexity. Endowing computers with this ability has long been a major goal of research in artificial intelligence (also called machine intelligence), a branch of experimental computer science that studies the nature of knowledge and its manipulation. Understanding the computational mechanisms that underlie the use of natural language is the central objec- tive of computational linguistics (see the text box at the end of the article), a science at the juncture of artificial in- telligence, philosophy, linguistics, and psychology. The two primary goals of this field are: • to understand how humans communicate • to create machines with human-like communication skills The first is a scientific goal pursued to help us understand ourselves. In particular, although we all are implicitly ex- pert in the use of natural language, we have only vague notions of the mental processes involved. A clearer in- sight into their essential nature and functioning might enable us to be better communicators, to train our children better in language skills, and even to design more efficient intercomputer communications. The second goal is an engineering one pursued for a practical purpose — to create machines that can com- municate with people in languages they already know. At present, only a small segment of the population, com- puter programmers, can communicate with computers. The advent of machines that understand natural lan- guages will make it possible for virtually anyone to make direct use of powerful computational systems. Progress in computational linguistics is facilitated by pursuing both of the above goals simultaneously. Crea- tion of mechanical schemes for dealing with some aspect of natural-language processing sheds light on how it might actually be performed by the human brain. Similarly, evidence derived from observing how people use language suggests prospective computational mechanisms or, more often, provides valuable insights into the reasons particular mechanical processes fail. To create computer systems that deal with certain significant subsets of natural-language phenomena, it is probably not necessary to perform the task in a way closely simulating computational processes in the human brain. This should not be surprising. Mechanical dish- washers use a nonhuman technique to produce a result equivalent to that of a human dishwasher. For inter- actions about very limited subject areas, we can hope to employ thoroughly nonhuman techniques in dealing with natural language. Nevertheless, machines concerned with any but the most mundane aspects of human language will probably have to deal with human psychology. After all, natural language has evolved as an efficient tool for conveying information between human minds. One of 304 September 1981 © BYTE Publications Inc The most comprehensive and useful computer reference in the world. • A mammoth volume covering everything from Access Methods to Working Set, in 1,523 pages, 470 articles and over 1,000 illustrations, tables and charts. • Authoritatively compiled by over 200 internationally respected authorities. If reply card has been removed, please write: The Library of Computer and Information Sciences Dept. 7-AR2, Riverside, N.J. 08075, to obtain membership information and application. Take the ENCYCLOPEDIA OF COMPUTER SCIENCE —a $60.00 value— yours for only $295 when you join The Library of Computer and Information Sciences. You simply agree to buy three more books— at handsome discounts— within the next 12 months. Find the answers to virtually all your data processing questions in the ENCYCLOPEDIA OF COMPUTER SCIENCE. Thousands of photos, diagrams, graphs and charts completely illuminate the ENCYCLOPEDIA'S clear and thorough coverage of every area of the computer sciences- software, hardware, languages, programs, systems, mathematics, networks, applications, theory, history and terminology. Appendices provide abbreviations, acronyms, special notations and many numerical tables. An additional highlight is a complete cross- reference system that assists the reader seeking in-depth information. What is The Library of Computer and Information Sciences? It's a book club especially designed for the com- puter professional. In the incredibly fast-moving world of data processing, where up-to-date knowledge is essential, we make it easy for you to keep totally informed on all areas of the informa- tion sciences. In addition, books are offered at discounts up to 30% off publishers' prices. Begin enjoying the club's benefits by accepting the ENCYCLOPEDIA OF COMPUTER SCIENCE. It's the perfect reference for computer professionals . . . and it's a great bargain, too. Circle 353 on inquiry card. The TELERAM S-100 Bubble Memory System A whole lot more... at 25% less Now there is a bubble memory system that is fully compatible with IEEE S100. And it's available from Teleram at 25% less cost compared to other bubble memory systems currently available-plus-it requires only 25% of the physical space. Each board has a capacity of 128K or 256K bytes of non-volatile storage and can be daisy chained to provide one megabyte. FEATURES: • DATA IS RETAINED AFTER POWER OFF • 40 MILLISECOND ACCESS TIME • CORRECTION FOR UP TO 5 BIT BURST ERRORS • CP/M COMPATIBLE • UNAFFECTED BY DUST • VERY HIGH RELIABILITY • OPERATES IN VERY HARSH ENVIRONMENTS • COMPLETELY MANUFACTURED IN THE U.S. • IDEALLY SUITED FOR PORTABLE AND PROCESS CONTROL APPLICATIONS The Teleram S-100 Bubble Memory System can provide the opportunity for new design concepts. For a free data sheet call or write: TELERAM COMMUNICATIONS CORPORATION, 2 CORPORATE PARK DRIVE, WHITE PLAINS, N.Y 10604, (914) 694-9270 COMMUNICATIONS CORPORATION 2 Corporate Park Drive White Plains, NY 10604 (914) 694-9270 TELEX 646658 the participants in a man-machine dialogue operates with all the constraints and richnesses of the human psyche; the other has to take these into account. The ultimate goal of creating machines that can in- teract in a facile manner with people remains far off, awaiting both improved information-processing algo- rithms and alternative computing architectures. How- ever, progress in the last decade has demonstrated the feasibility of employing today's computers to deal with natural-language input in highly restricted contexts. Futhermore, microcomputer implementation of these limited language-processing techniques is leading to more practical, cost-effective systems. In this article, we offer an overview of the potential ap- plications, experimental systems, existing techniques, research problems, and future prospects in this rapidly evolving field. We will address major issues in natural- language processing by focusing on several representative systems, necessarily leaving much important work unmentioned. For example, we will not discuss the com- plex issues involved in understanding spoken (as opposed to typed) language. Our intentions are to demonstrate that natural-language processing techniques are useful now, to reveal the richness of the computations per- formed by human natural-language communicators, and to explain why the fluent use of natural language by ma- chines remains an elusive aspiration. Applications of Natural-Language Processing To motivate our discussion about how to approach the technological goal of creating a machine with human-like communication skills, let us consider some potential areas for the application of natural-language processing: • Machine translation — The oldest dream of computa- tional linguistics is of a mechanical device that can read documents written in one natural language and produce corresponding documents written in other languages, but with equivalent meanings. In fact, the birth of computa- tional linguistics occurred in 1946, when Warren Weaver and A Donald Booth first suggested the use of a digital computer to create such a device. The Association for Computational Linguistics, the professional organization in this discipline, was originally named the Association for Machine Translation and Computational Linguistics. • Document understanding — Beyond simply translating a document from one language to another, a device might read and understand documents, fitting their information into a larger framework of knowledge. A practical device of this sort would read and assimilate a document much as a person would. The device might subsequently pro- duce abstractions of the document, alert people likely to be interested in it, or answer specific questions based on its information. If such a device had read many docu- ments, it might be able to act as a librarian, directing users to pertinent references. • Document generation — A task related to document understanding is document generation. We can envisage a device that translates information stored in a formal 306 September 1961 © BYTE Publications Inc OLWL^lMJJCSuM COMES WITH: (ADDITIONAL) * WORD STAR®WORD PROCESSOR * GENERAL LEDGER * ACCOUNTS PAYABLE a SALES ORDER ENTRY a ACCOUNTS RECEIVABLE a INVENTORY CONTROL □ □□ ONLY QUANTITY DISCOUNTS AVAILABLE! INCLUDING CP/M2.2® ($4950.00 INCLUDING ACCOUNTING SOFTWARE AND WORD STAR" ) 320K MINI DRIVES SHOWN, 8" and 554" 10MB HARD DISK OPTIONAL IMMEDIATE DELI VERY! MgS MICRO 1 YEAR PARTS WARRANTY! 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Circle 368 on inquiry card. MACHINE Figure 1: The typical nontechnical user confronts a "black box" that contains large amounts of knowledge on a given subject. language in a computer's memory into ordinary lan- guage. For example, the designer of an automobile engine might describe repair procedures in a formal language. (After all, we expect that the designing of mechanical de- vices will someday be done principally by computer sys- tems, which may prefer formal languages.) From this for- mal description, instruction manuals in various lan- guages could be generated. A more sophisticated system could generate special manuals for particular groups or individuals. Taking into EXPAND APPLE AND ATARI 16K RAM CARD These exciting new additions to our line will meet the demand for low cost alternatives to the higher priced language and ram cards. The ConComp Apple II 16K Ram Card will work with all exisitng software compatible with the Apple Language Card' and the Microsoft Z-80 Softcard. 5 Allowing up to 64K of user memory, the Ram Card helps make complete use of Pascal, CP/M, 4 and larger programs like VisiCalc. 3 The Atari 800 2 version is compatible with all Atari software. Both cards are constructed using high-speed high-quality dynamic RAM and come with a full one year warranty. For more information please call or write. APPLE II $130 ATARI 800 $89 'Trademark of Apple Computer Inc. 'Trademark of Atari Inc. 'Trademark of Personal Software Inc. 'Trademark of Digital Research 'Trademark of Microsoft Consumer Products. Inc. Anibbb froa: ConComp Industries 8338 Center Dr. L« Meta, CA 92041 (714) 464-S373 Dealer Inquiries Invited account that mechanics know much about auto repair, a smart system would generate a different manual for mechanics than for automobile owners, but on the basis of the same underlying information. Information on elementary mechanical tasks would be included in manuals for less knowledgeable individuals. An ultimate system would tailor a manual to the background of each individual. It is worth noting that a repair manual need not be written in linear sequence in a typical book format. Using a computer, advice about how to proceed on any par- ticular problem could be dynamically generated to apply specifically to the task at hand. We will return to this topic later in the article. • As part of a system — An interesting use of natural-lan- guage processing is as part of a larger computer-based system. For example, imagine devices that not only com- municate in English, but also: • provide answers to questions by accessing large data bases • control complex equipment such as industrial robots, power generators, or missile systems • furnish expert advice about medical problems, mechanical repairs, how to buy stocks, or what to cook for supper • teach courses in a broad range of subjects An extreme example of a computer-based system that would use natural-language processing as an integral component is a robot that communicates in English. Such a robot might be expected to perform as many tasks in- volving the use of natural language as might be done by a human assistant. The importance of these potential applications and the basic science needed to make them possible has long been appreciated by scientific-funding agencies of the United States government. Current progress in the field is due largely to support from the Defense Advanced Research Projects Agency, the National Science Foundation, and the Office of Naval Research. What Existing Systems Can Do One of the most important and feasible areas for the application of natural-language processing is accessing data in data bases. Billions of dollars have been spent in collecting and encoding such data. However, this infor- mation is generally not readily available to the people who need it. The situation is illustrated by figure 1. An executive in the widget business wants to direct a simple question to his black box. He wants to know, "How many widgets did we sell in August?" He knows the information is in the black box, but he lacks the ex- pertise to make the box understand him. As shown in figure 2, he must find an interpreter (com- puter programmer) who can translate his question into a formal query to give to the machine. Unfortunately, pro- grammers are out drinking coffee when you need them, 308 September 1981 © BYTE Publications lnc Circle 90 on inquiry card. When it comes to microcomputer software we wrote the book. \X ■sft •was SCI SO' rtWdte How do you stay up-to-the-minute with the rapidly changing world of microcomputer software? Get the Lifeboat Catalog. The Latest Innovations The new Lifeboat Catalog is packed with the latest state-of-the-art software. And if we publish a new program after the latest catalog has gone to press, we enclose a flash bulletin in your copy. The Greatest Selection Because Lifeboat is the world's largest pub- lisher of microcomputer software, our catalog offers you the greatest selection of programs for busi- ness, professional and personal use. Our more than 200 programs range from integrated accounting and professional practice systems to office tools for book- keepers and secretaries to sophisticated tools for pro- grammers. Included are business systems, word processors, programming languages, database man- agement systems, application tools and advanced sys- tems utilities. We specialize in software that runs on most small business computers. Our more than 60 media formats, including floppy disks, data cartridges, magnetic tape and disk cartridges, support well over 100 computer brands of domestic and foreign manufacture. Vfttft tuttsu' pport Get Full Support We give the crucial dimension of after-sales service and full support to everything we sell. That includes: •A telephone hotline where technical and customer service representatives will answer your questions 11 hours a day. •An update service for software and documentation. • Telephone, telex and mail-order service at the New York headquarters and at overseas offices in England, France, Switzerland, West Germany and Japan. •Export service providing software delivery to six continents. •Subscriptions to Li/eJines™, the monthly magazine that offers comparative reviews, tips, techniques, iden- tified bugs and updates that keep you abreast of change. Get It Now Lifeboat now serves tens of thousands of satisfied customers with our breadth of up-to-date, fully tested, fully supported and competitively priced software. You may not need all we offer, but we offer just what you need. After all, we wrote the book. Lifeboat Associates 1651 Third Ave New York. N Y. 10028 Tel: (2121 860-0300 Telex; 640693 [LBS0FT NYK) TWX: 710-581-2524 Lifeboat Associates GmbH P0 Box 168. Aegenstrasse 35 CH 6340 Baar. Switzerland Tel: 042-31-2931 Telex; 865265 (MIC0 CHI LIFEBOAT WORLDWIDE offers you the world's largest library of software. Contact your nearest dealer or Lifeboat: | Mail coupon to: Lifeboat Associates, 1651 Third Avenue, New York, New York 10028 or call (212) 860-0300. § Lifeboat Inc. OK Bldg . 5F 1-2-8. Shiba-Daimon Minato-ku. Tokyo 105. Japan Tel: 03-437-3901 Telex: 2423296 (LBJTY01 Lifeboat Associates. Ltd. P0 Box 125 London WC2H 9LU. England Tel: 01-836-9028 Telex: 893709 (LBSOFTG) Intersoft GmbH Lifeboat Associates, SARL Schlossgartenweg 5 10. Grande Rue Charles de Gaulle D-8045lsmaning. W. Germany 92600 Asmeres. France Tel: 089-966-444 Tel- 1-733-08-04 Telex: 5213643 (IS0FD) Telex: 250303 (PUBLIC X PARISI lifeboat Associates Software with full support □ Pleas&send me a free Lifeboat Catalog. D Please send me Lifelines subscription information. Name Title Company- Street City _Zip_ Li Li le lines is a trademark of Lifelines Publishing Corporation. Circle 190 on Inquiry card. BYTE September 1981 309 ARE YOU m You are ready for MICRO if you want to. - . D Go beyond canned software □ Use your computer for more than games □ Learn advanced programming techniques □ Understand the inner workings of your computer □ Get the most out of your 6502/6809 system Month after month, MICRO gives readers sophisticated software applications, detailed discussions of programming languages, and in- depth hardware tutorials. To get the most out of your machine, say YES to MICRO today! We accept VISA or Mastercard. $18.00 per year in the U.S., $21.00 elsewhere. Use Our 24-hour Toll-free Service 800-227-1 61 7ex, Me In California: 800-772-3545, Ext. 546 /AlCftO 34 Chelmsford Street P.O.Box 6502 Chelmsford, MA 0I824 INTERPRETER Figure 2: The nontechnical user obtains information from the computer through the use of an interpreter (computer program- mer), who translates the English question into a form the machine understands. or they are working on a project more important than your project —so they cannot help you this week. When a programmer is available, misunderstandings often occur and there are problems in creating proper code. By the time an answer is extracted from the computer, it may no longer be timely and may not even be relevant! The LADDER System To produce timely answers to questions and quickly clear up problems as to how a decision-maker's question is to be interpreted, the turnaround time must be cut from hours or days to seconds. Research groups around the world are attempting to do this by automating the programmer in figure 2. For exam- ple, the LADDER system developed at SRI International (see references 11 and 12 at the end of this article) is capable of translating a question such as: TO WHAT COUNTRY DOES THE FASTEST SUB BELONG? into either the code of listing 1 or listing 2, depending on which DBMS (data-base management system) has the relevant data. An explanation of these segments of code is unnecessary here. The point is that systems exist that are capable of accepting simple English queries specifying Text continued on page 314 310 September 1981 © BYTE Publications Inc DEALERS: By now you know that it takes SOFTWARE TO SELL COMPUTERS and International Micro Systems can provide you with the largest selection of quality business applications ever developed for the microcomputer industry. If you are just looking for a G.L., A/P, and Payroll, you can find them in a dozen ads in this magazine. But thers's a much bigger market for micros out therethan that. Where can you find a fully interfaced Wholesale/Retail Distribution System? How about Manufacturing Inventory Control including Production Scheduling & Control. See that one anywhere else? Maybe your market is Medical/Dental and IMS has the full systems there too. You can't sell computers without software and IMS has the finest selection of software available for you. Each system has been developed by the IMS professional staff and we support what we sell. But thats not all. International Micro Systems has the strongest dealer marketing plan in the industry. With our $ 245 Dealer Demo System. we put all the software shown below in your office or store ready to demo to your prospects and we include the promotional material and our unique video sales presentation to help you move systems. Give us a call or drop us a card and let us show you what selling business systems should be all about. Financial Systems GL, A/P, A/R Payroll Cash Receipts/Disb. Job Costing Mailing List Mgmt. Medical/Dental Office. Scheduler Patient Billing & A7R Insurance Forms Governmental/Educational Student Record Keeping and Scheduling Fund Accounting Wholesale Distribution System Purchasing & Receiving Inventory Control Invoicing & Receivables Salesman Comm. Reporting Backorder Management Manufacturing Inventory Control Finished Goods Inventory Mgmt Parts Inventory Mgmt Parts Purchasing & Receiving Bill of Materia Production Scheduling INTERNATIONAL IICRO S YSTEMS Circle 169 on inquiry card. BYTE September 1981 311 Listing Is An English-language query translated to an equivalent program in DATALANGUAGE. Listing 2: An English-language query translated to an equivalent DBMS20 program. English Query — To what country does the fastest sub belong? DATALANGUAGE Query— BEGIN DECLARE Yl STRING (,100) ,D = '}' DECLARE Y2 STRING (,100) ,D = T Y2 = '00.0' DECLARE Y3 INTEGER Y3 = DECLARE Y5 STRING (,100) ,D = '}' Y5 = DECLARE Y4 STRING (,100) ,D = '}' Y4 = FOR Rl IN SHIPCLASCHAR WITH (R1.TYPE2 EQ l S') AND (Rl.TYPElEQ'S') FOR R2 IN SHIPCLASDIR WITH (R2.SHIPCLAS EQ Rl.SHIPCLAS) FOR R3 IN SHIP WITH (R3.UICVCN EQ R2.UICVCN) BEGIN Yl = R3.MCSF IF Yl LE '99.9' AND Y2 LT Yl THEN BEGIN Y2 = Yl Y5 = R3.NAT Y4 = R3.NAM Y3 = 1 END END IF Y3 EQ 1 THEN BEGIN NSTDPORT. STRING 1 = Y4 NSTDPORT.STRING2 = Y5 END END Kill Surges Like Lightning! Permanent protection for small computers, communi- cations, medical and other sensitive electronic equip- ment. Surge Sentry works in parallel with the power line to shunt destructive power surges in picoseconds! Triggers at 10% above the nominal peak voltage. At $89.50, it's less than the cost of a service call. Easy to install for immediate protection. Several models to choose from to fit your specific application. For details and a free brochure, call or write: M IgJRKS ENTERPRISES, INC. English Query — To what country does the fastest sub belong? DBMS20 Query— COMPUTE XSTRX 11 = '00.0'$ COMPUTE XY10 = $ FIND FIRST SHIPCLASCHAR RECORD OF BLUEAREA AREAS 13 IF ERROR-STATUS = 307 GO TO 14 $ COMPUTE XAND16 = $ IF SHIPCLASCHAR-TYPE2 NE 'S' GO TO 17 $ COMPUTE XAND 16 = 1 $ 17 IFXAND16 = 0GOTO 15$ COMPUTE XAND 18 = $ IF SHIPCLASCHAR-TYPE1 NE 'S' GO TO 19 $ COMPUTE XAND 18 = 1 $ 19 IF XAND18 = GO TO 15 $ COMPUTE XSTRZ12 = SHIPCLASCHAR-MCS $ IF XSTRZ12 LT '00.0' OR XSTRX11 LE XSTRZ12 GO TO 15 $ COMPUTE XSTRX 11 = XSTRZ12 $ COMPUTE XY10 = 1 $ COMPUTE XSTR29 = SHIPCLASCHAR-MCS $ 15 FIND NEXT SHIPCLASCHAR RECORD OF BLUEAREA AREAS GO TO 13 $ 208 Mount Hermon Road #2 Scotts Valley, CA 95066 (408) 438-5760 Dealer inquiries invited. 14 20 24 26 28 30 34 35 37 36 32 31 22 21 IF XY10 = GO TO XT $ FIND FIRST SHIPCLASCHAR RECORD OF BLUEAREA AREA $ IF ERROR-STATUS = 307 GO TO 21 $ COMPUTE XAND23 = $ IF SHIPCLASCHAR-TYPE2 NE 'S' GO TO 24 $ COMPUTE XAND23 = 1 $ IF XAND23 = GO TO 22 $ COMPUTE XAND25 = $ IF SHIPCLASCHAR-TYPE1 NE 'S' GO TO 26 $ COMPUTE XAND25 = 1 $ IF XAND25 = GO TO 22 $ COMPUTE XAND27 = $ IF SHIPCLASCHAR-MCS NE XSTR29 GO TO 28 $ COMPUTE XAND27 = 1 $ IF XAND27 = GO TO 22 $ FIND FIRST SHIPCLASDIR RECORD OF BLUEAREA AREA $ IF ERROR-STATUS = 307 GO TO 31 $ COMPUTE XAND33 = $ IF SHIPCLASDIR-SHIPCLAS NE SHIPCLASCHAR- SHIPCLAS GO TO 34 $ COMPUTE XAND33 = 1 $ IF XAND33 = GO TO 32 $ SET SHIP-UICVCN TO SHIPCLASDIR-UICVCN $ FIND SHIP RECORD $ IF ERROR-STATUS = 326 GO TO 36 $ PRINT SHIP-NAM SHIP-NAT $ FIND DUPLICATE SHIP RECORD $ GO TO 35 $ * $ FIND NEXT SHIPCLASDIR RECORD OF BLUEAREA AREA $ GO TO 30 $ * $ FIND NEXT SHIPCLASCHAR RECORD OF BLUEAREA AREAS GO TO 20 $ * $ GO TO XT $ END 312 September 1981 © BYTE PublicaSons Inc Circle 309 on inquiry card. 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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 is a trademark of Zilog Corp. CP/M and MP(M are trademarks of Digital Research Corp CBASIC is a trademark of Compiler Systems Inc 10330 Brecksville Road, Brecksville (Cleveland), Ohio 44141 Phone: 216/526-0838 / 526-0839 Telex: 241596 Circle 307 on inquiry card. Listing 3: An actual conversation with the LADDER system. Boldface words represent user input. Material in square brackets replaces lengthy material not relevant to this article. 1— Give me the length of the Kenedy. spellings KENNEDY PARSED! Give the length of the ship KENNEDY IF LEN - 1072 2— width and draft PARSED! Trying Ellipsis: GIVE ME WIDTH AND DRAFT OF THE KENEDY Give the beam and draft of the ship KENNEDY IF (BEAM 130 DFT 36) 3 — Who is her commander? Give the rank and name of the commander of the ship KENNEDY IF CRANK CAPT NAME MOFFETT P) 4— What about the Fox? PARSED! Trying Ellipsis on: THE FOX WHO IS THE FOX COMMANDER Give the rank and name of the commander of the ship FOX (RANK CAPT NAME EVERETT I) 5 — What U.S. merchant ships carrying vanadium ore are within 500 miles of the Kimlow? PARSED! Give the position of and time at position for the ship KIMLOW T Give the name of merchant American ship S where the type of cargo on S is VNAD the great-circle distance from the position of S to 15-33N, 30- 10W, is less than or equal to 500 SHIP = GREENVILLE VICTORY, CRAIN ME, TOTOR 6 — How fast are the U.S. subs with lengths greater than 150 feet? PARSED! Give the maximum cruising speed for and name of American ship S where the first character of the type of S is S the second character of the type of S is S the length of S is greater than 150 [A long table relating the names and maximum cruising speeds of American submarines is printed.] 7 — What French ships are at readiness status 1? PARSED! Give the name of French ship S where the state of readiness of S is 1 There is no French ship S NONE Text continued from page 310: what information a user wants, then generating fairly complex programs specifying how the computer is to retrieve the information. Two problems are being confronted together: Problem 1: The system must translate from English into a formal language. Problem 2: The system must convert a statement of what is wanted into a statement of how to get it. Problem 2 is concerned with automatic programming, an artificial-intelligence problem currently receiving much attention (see reference 2). (Fortunately, most work on natural-language processing needs to consider only a highly restricted subset of this general problem.) What it's like to use a system such as LADDER is sug- gested by the transcript, shown in listing 3, of an actual interaction. The system prompts users with a transaction number followed by a hyphen. The user then types in a question or command. (In this and future listings, we refer to the question half as a query and to the ques- tion/response pair as an interaction.) Query 1, "Give me the length of the Kenedy," contains a misspelled word. LADDER corrects this automatically, typing a note to the user directly below the input line. Once LADDER has corrected the spelling error and completed an analysis of the input, it types the message "PARSED!", and displays its interpretation of the user's query. The system then calls a remote data base to retrieve the answer— in this case, the length (abbreviated to LEN) of the Kennedy is 1072 (feet). Query 2 is not a complete sentence. In fact, it makes no sense when considered in isolation. But in the context of the preceding query, it is clear that the intended meaning is, "Give me the width and draft of the Kennedy." Leav- ing out pieces of a sentence is called ellipsis. Processing such elliptical inputs is more difficult than it may seem. The system has to avoid such interpretations as, "Give me the length of the width and draft," or even, "Give width and draft the length of the Kennedy." Query 3 illustrates the use of a pronoun, another linguistic construct that cannot be interpreted in isola- tion. Query 4 demonstrates a more sophisticated form of ellipsis in which the analysis involves more than just grammatical substitution of the new input into the old one. (This is accomplished in LADDER by looking for "WHAT ABOUT" at the beginning of an input, ind then applying the standard elliptical technique what follows.) Query 5 illustrates a major benefit of natural-language processing: the user can interact with the system in terms of the job being done, letting the system be concerned with what is required from the data base. Though this is only one question from the user's perspective, it requires two questions of the data base. First, the location of the Kimlow must be determined, and then the appropriate ships within 500 miles of that location must be retrieved. The process of translating from the user's terms to those of the data base obstructs the user's decision-making job. It is therefore an appropriate process to automate. Interaction 6 causes a large body of information to be retrieved from the data base. Althoug omitted from the listing to save space, a table summarizing the answer is displayed to the user. Interaction 7 shows an example of a cooperative response to the user's question. The user asks a question about the readiness of French ships. However, the data base contains no information about French ships. There- fore, the literal answer to the user's question, NONE, is inappropriate by itself, since it leads the user to believe all French ships are unready. To provide a more informative response, LADDER presents additional information showing the rationale for producing the NONE response. 314 September 1981 © BYTE Publications Inc The A2-3D1 Graphics Family. . Nowfor non-programmers! cfflss^ A2-3D1 Graphics Package A2-GE1 Graphics Edit $59.95 on disk (32K required) $34.95 on disk (48K and $49.95 on cassette (16K A2-3D1 required) required) A2-3D/A Saturn Navii A2-3D2 Enhancement $24.95 on disk (48K, A2- $24.95 on disk (48K and and Applesoft required) A2-3D1 required) $19.95 on cassette (32K and A2-3D1 required) For direct order, include $3 for UPS or $5 for first class mail delivery. Illinois residents add 5% sales tax. Visa and Master Card accepted. Running on the Apple II: A2-3D/A Saturn Navigator A2-GE1 Graphics Editor $34.95 on disk (48K and A2-3D1 required) A2-3D/A Saturn Navigator $24.95 on disk (48K, A2-3D1 , and Applesoft required) professional 3D and 2D graphics forthe Apple II The A2-3D1 is the graphics utility you can depend on whether you're mapping a town, presenting charts at a business meeting, or animating games. Now this versatility is available for the non- programmer with the A2-GE1 graphics editor and programmer. Create images as you view them. Scan them, animate them, combine them, or add text or labels. With a minimum of fuss, you can prepare all sorts of scientific, business, or educational presentations. Add the A2-3D2 enhancement package for color, and as a bonus you'll also be able to manipulate images independently of each other— as many different objects at once as your memory will accommodate. When it's time for some challenging and educational entertainment, run the A2-3D/A Saturn Navigator. You'll enjoy an adventurous flight to Saturn, enter its orbit, and rendezvous with an orbital space station that awaits your arrival. We've reached our goal of giving you the most sophisticated graphics utilities in the market- place ... see them now at your dealer! MfeLOGIC Communications Corp. BoxV, Savoy, I L 61 874 (217)359-8482 Telex: 206995 "Apple" is the registered trademark of Apple Computer Inc. Circle 339 on inquiry card. LADDER'S methods for dealing with natural-language inputs are similar to those used by compilers and inter- preters for such languages as BASIC and Pascal. For ex- ample, a BASIC interpreter might deal with assignment statements by looking for the pattern: LET < variable > = < expression > . This pattern could match an instruction of the form: LET X = 5 + Y with "X" filling the role of the < variable > and "5 + Y" filling the role of the < expression > . Associated with this pattern, the interpreter would have a function for storing the value of the expression into the memory location named by X. Similarly, LADDER uses patterns such as: WHAT THE < SHIP-ATTRIBUTES > OF < SHIP-DESCRIPTION > that can match sentences such as: WHAT ARE THE LENGTHS AND DRAFTS OF US CARRIERS? Like an interpreter or compiler, LADDER associates a function with each pattern. The function associated with the example just cited would produce calls to the data- base management system to retrieve attributes of ships and take as parameters the names of the attributes and a description of the ships of interest. Most of LADDER'S knowledge about language and the world is implicitly en- coded in its grammar and associated functions. The grammar contains much information about the particular data base being queried and is by no means a standard grammar of English. A grammar of this type is called a pragmatic or semantic grammar (see references 4 and 11). Summary of LADDER-Like Systems In a later section, we will say more about what systems like LADDER can do. For now, it is sufficient to note the following: • The computer capability shown in the transcript of listing 3 is of considerable practical utility. • LADDER deals with a relatively large and complex data base that includes over 100 fields in fourteen files and has records for 40,000 ships. • LADDER has been performing at this level of capability since 1976 (except for the cooperative responses such as those in interaction 7, which are relatively new — see reference 14). • There are several systems in laboratories around the world that are capable of essentially the same level of per- formance as shown in listing 3. These include the systems described in references 10, 14, 24, 25, 26, and 31. Building Blocks for Microcomputer Systems, Dedicated Controllers and Test R 2 l/0 S-100 ROM, RAM & I/O BOARD ECT's R 2 l/0 is an S-100 Bus I/O Board with 3 Serial I/O Ports (UART's), 1 Parallel I/O Port, 4 Status Ports, 2K of ROM with the 8080 Apple Monitor Program and 2K of Static RAM. $295.00 RM-10 S-100 RACK MOUNT CARD CAGE ECT's RM-10 is a rack mount 10 slot Card Cage with Power Supply, consisting of an ECT-100 rack mount Card Cage (19"W x 12.25"H x 8"D), the MB-10 Mother Board (with ground plane and termination) all 10 connectors and guides and the PS-15A Power Supply (15A@8V, 1.5A@ ± 16V). $295 00 Specializing in Quality Microcomputer Hardware Industrial • Educational • Small Business • Personal Card Cages, Power Supplies, Mainframes, CPU's, Memory, IIO, OEM Variations ELECTRONIC CONTROL TECHNOLOGY 763 Ramsey Ave., Hillside, NJ 07205 316 September 1981 © BYTE Publications Inc (201) 686-8080 Circle 134 on inquiry card. Our newest developme 3ntinuing expansion of t 'stem™ software. version JOHN BRACKET!; President, SofTech Microsystems Backed by a dedicated team of professionals, SofTech Micro- systems continues to enhance the world's most widely-used, portable software development system. Today it's the UCSD p-System, Version IV. Able to run on most major microprocessors including 8086, Z-80, 8080, 8085, 6502, 6809, 9900 and LSI-11™, Version IV is the developer's tool to make perfect programs more possible. It consolidates all the best fea- tures of earlier versions, while allowing for much larger applications, concurrent processing and improved debugging. With the addition of BASIC, more macro cross-assemblers, and improved docu- mentation, Version IV is truly a total, professional software development and execution environment. And, it's backed by SofTech Microsystems, the first to deliver a complete, portable software system for most major microprocessors with UCSD Pascal™, FORTRAN-77, BASIC, and multiple assemblers. For tomorrow, the expansion continues. More 16 bit microprocessor installations. The performance impact of native code generation. New system utilities and languages. New tools for creating applications more rapidly. The SofTech Microsystems team is at work today to increase your options for the future. Get the software system that's going places. Distribution licenses and single copies available. Write or call for details, so you can start going places, too. micRosvsTems a SUBSIDIRF1V OF SOFTECH For the software that's going places. 9494 Black Mountain Road, San Diego, CA 92126, (714) 578-6105 TWX 910-335-1594 UCSD p- System and UCSD Pascalare trademarks of the Regents of the University of California. LSI-11 is a trademark of Digital Equipment Corp. Circle 330 on Inquiry card. BYTE September 1981 317 Listing 4: A dialogue between an expert and an apprentice repairman showing definitely determined noun phrases (underlined). A: E: HOW DO J_ REMOVE THE FLYWHEEL ? FIRST LOOSEN THE TWO SMALL ALLEN HEAD SETSCREWS HOLDING IT TO THE SHAFT THEN PULL IT OFF. THE TWO SETSCREWS ARE LOOSE BUT I'M HAVING TROUBLE GETTING THE WHEEL OFF. USE THE WHEEL PULLER . DO YOU KNOW HOW? NO LOOSEN THE SCREW IN THE CENTER AND PLACE THE JAWS AROUND THE HUB OF THE WHEEL ; THEN TIGHTEN THE SCREW. THE LITTLE METAL SEMICIRCL E FELL OFF WHEN J_ TOOK THE WHEEL OFF. For restricted classes of applications, systems such as LADDER provide language-processing capabilities that are very useful. Nevertheless, LADDER falls far short of being an ideal system, both conceptually and linguistical- ly. LADDER'S concept of the world is based on the underlying conventional data-base management system to which it provides access. Data-base management systems can effectively store large numbers of individual, concrete facts, such as: Isolated from all contexts, this question should be inter- preted as a request for the names of the commanding of- ficers of all US tankers in the data base. But if a user has just asked the question, "What is the status of convoy C86? " and has received information on a number of ships in the convoy, including two US tankers, the sam- ple question should elicit the captains' names for only the two tankers in the convoy. LADDER ignores the context, however, answering the question as if it had been asked in isolation. The ability to follow a changing context and make ac- curate references to prominent objects is a fundamental characteristic of human communication. In fact, about half the words used in ordinary speech are found in DEF NPs (definitely determined noun phrases), the linguistic constructions most often used to refer to objects in con- text. Note, for example, all the definitely determined noun phrases underlined in the dialogue shown in listing 4. The need to understand context throws considerable doubt on the idea of building natural-language interfaces to systems with knowledge bases independent of the language-processing system itself. This is because the in- formation in the knowledge base may be needed simply for comprehension of a question. For example, to under- stand the phrase "the filter" in: THE KENNEDY IS OWNED BY THE US But they are incapable of dealing in a general way with more logically complex notions, such as disjunction, quantification, implication, causality, and possibility. They act as if they were dealing with information about a world containing a fixed number of objects and relation- ships among them, with the objects and relationships be- ing immutable. Perhaps LADDER'S most important linguistic deficien- cy is its limited notion of linguistic context. With minor (though useful) exceptions, LADDER treats each input as if it were given in isolation. To perceive the problem, let's consider the question: WHO ARE THE CAPTAINS OF THE US TANKERS? IF I CHANGE THE OIL IN MY CAR, WHERE SHOULD I LOOK FOR THE FILTER? it is necessary to know that automobiles use oil cleaned by a filter. Such knowledge makes possible the assump- tion that such a filter, the one on the user's car, is the referent of "the filter." We cannot translate the question into a formal query to an auto-maintenance system unless the translation system also has some information about the nature of auto maintenance. Systems for Dealing with Dynamic Microworlds SHRDLU, a system developed by Terry Winograd at MIT around 1970 (see reference 29), was one of the first systems to deal with some of the complexities of context and address a domain of greater logical complexity than UCSD p-System* for the INTE2TEC SUPE3BRAIN (TM) With UCSD Pascal*, FORTRAN, and BASIC VERSION IV.O UCSD p-System includes: operating system, editor, filer, library, Z80 assembler, and documentation. with Pascal $ 600 with FORTRAN 600 with BASIC 500 THE DATALEK COMPANY 1431 Twelfth Avenue, San Francisco, CA 94122 Telephone: (415) 665-4467 ■ UCSD p-System and UCSD Pascal are trademarks of the Regents of the University of California '"Trademark of Intertec Data Systems 318 September 1981 © BYTE Publications Inc Circle 103 on inquiry card. If you need A/168000, Z8000, or 8086 Software, take it off our shelf. HtMENWAY : /»ssoc:Arts inc. 0SM*® M68000 MUOOO Op«tJng titmm dim • (iimn Why wait up to 6 months for high quality 16-bit resident system software, when you can get it now? Hemenway Associates can give you the software tools you need to get the most out of your 16-bit hardware. Because 8086, Z8000 and 68000 Systems Software is sitting on our shelves right now. Single user operating systems, macro assemblers, text editors, floating point packages, multi-tasking operating sys- tems, linking loaders and PASCAL com- pilers are all ready for immediate delivery. You've heard about Hemenway Associates' system designs in the pages of EDN. But now you can have Hemenway- designed software for) processor. Our software < to any hardware confrgurarit manufacturers evaluation boards tc blown microcomputers. It's efficient, to-use and backed by ongoing support. So whether you're a microcomputer manufacturer, software developer or indi- vidual microcomputer owner, Hemenway* has the software for you. For the hard facts on Hemenway soft- ware, write or call: Hemenway Associates, 101 Tremont Street, Boston, Massachusetts 02108. Phone:617-426-1931. TWX 710 321 1203. TELEX 921735. Ill till Circle 159 on inquiry card. HGMeNWAY ASSOCIATES, INC. When it comes to software, come to Hemenway. ^rr ARM Figure 3: The microworld of blocks used by the SHRDLU pro- gram, which can manipulate objects in the microworld and answer questions about them. Listing 5: An actual conversation with the SHRDLU system. Associated images of the blocks microworld are given in figures 3, 4, and 5. 1 — PICK UP A BIG RED BLOCK. OK. 2 — GRASP THE PYRAMID. I DON'T UNDERSTAND WHICH PYRAMID YOU MEAN. 3 — FIND A BLOCK WHICH IS TALLER THAN THE ONE YOU ARE HOLDING AND PUT IT IN THE BOX. BY "IT" I ASSUME YOU MEAN THE BLOCK WHICH IS TALLER THAN THE ONE I AM HOLDING. OK. 4 - WHAT DOES THE BOX CONTAIN? THE BLUE PYRAMID AND THE BLUE BLOCK. 5 — WHAT IS THE PYRAMID SUPPORTED BY? THE BOX. 6 — HOW MANY BLOCKS ARE NOT IN THE BOX? FOUR OF THEM. 7 — WHY DID YOU CLEAR OFF THE RED BLOCK? TO PICK IT UP. 8 — WHY DID YOU DO THAT? BECAUSE YOU ASKED ME TO. Figure 4: SHRDLU in the process of executing the command "PICK UP A BIG RED BLOCK". can be handled by a conventional data-base management system. An example of the types of interactions SHRDLU can support is shown in listing 5. At the beginning of the dialogue, both user and system are talking about a small microworld of blocks configured as shown in figure 3. In interaction 1 of listing 5, SHRDLU is asked to pick up a big red block. Since there is only one such block in the microworld, SHRDLU knows what to pick up. Com- plicating the situation, however, is a green block resting on the big red block. SHRDLU is forced to devise a plan that involves moving the simulated robot arm to the green block, lifting the green block, moving the block to a clear place on the table, placing the green block on the table, releasing the green block, returning to the red block, grasping the red block, and, finally, lifting it up. Figure 5: The microworld after execution of the command "FIND A BLOCK WHICH IS TALLER THAN THE ONE YOU ARE HOLDING AND PUT IT IN THE BOX". (This takes place after the action of figure 4.) When this is done (after considerable computation time), the microworld configuration is as shown in figure 4 and SHRDLU responds with a simple "OK". In interaction 2, the user asks SHRDLU to grasp "the pyramid." But there are two pyramids in the microworld context, and the linguistic context contains no clues to choose between them. SHRDLU realizes that it cannot identify the referent of "the pyramid" and tells the user so. Interaction 3 reveals SHRDLU's ability to deal with a fairly complex noun phrase containing a relative clause and a comparative construction, and to handle prob- lematic words such as "one" and "it." The result of this 320 September 1981 © BYTE Publications Inc C»' „d»- IS** 1 .O ** p^ e % \&\ 2.9°/° •j^ W£* %f ,,**» .,*«* »tf e *c»* 0»« .<* III *2& ,***>* \v# SI' SS« ^■55" T.S°'» _1»9 00°/= s «?. Vs. V^2SS>- B 'V.n■ ■ trademark of tin kitil Corp LSI II ii a Iraiemart of Digital Equipment Corp. EXOftriiar Ii a trademark of Motorola Circle 61 on inquiry card. BYTE September 1981 323 DYNACOMP Quality software for*: ATARI TRS-80 (Level II)** PET NORTH STAR APPLE II Plus CP/M Disks/Diskettes CARD GAMES BRIDGE 2.0 (Available for all computers) Price: $17.95 CasMtte/$21.95 Diskette An all-inclusive version of this most popular of card games. This program both BIDS and PLAYS either contract or duplicate bridge. Depending on the contract, your computer opponents will either play the offense OR defense. If you bid too high, the computer will double your contract! BRIDGE 2.0 provides challenging entertainment for advanced players and is an excellent learning tool for the bridge novice. See the software review in 80 Software Critique. HEARTS 1.5 (Available for all computers) Price: $15.95 Cassette/S 19.95 Diskette An exciting and entertaining computer version of this popular card game. Hearts is a trick-oriented game in which the purpose is not to take any hearts or the queen of spades, Play against two computer opponents who are armed with hard-to-beat playing strategies. HEARTS 1.5 is an ideal game for in- troducing the uninitiated (your spouse) to computers. See the software review in 80 Software Critique. STUD POKER (Atari only) Price: $1 1 95 Cassette/S 1 5. 95 Duke tie This is the classic gambler's card game. The computer deals the cards one at a time and you (and the computer) bet on what you see. The computer does not cheat and usually bets the odds. However, it sometimes bluffsl Also included is a five card draw poker betting practice program. This package will run on a 16K ATARI. Color, graphics, sound. POKER PARTY (Available for till computers) Price: $17.95 Cmuetlc/$21.95 Diikette POKER PARTY is a draw poker simulation based on the book, POKER, by Oswald Jacoby. This is the most comprehensive version available for microcomputers. The party consists of yourself and six other (computer) players. Each of these players (you will get to know them) has a difMftnt personality in the form of a varying propensity to bluff or fold under pressure. Practice with POKER PARTY before going to that expensive game tonight! Apple Cassette and diskette versions require a 32 K (or larger) Apple II. CRIBB AGE 2.0 (TRS-80 only) Price: $14.95 C*uclte/$18.95 Diskette This is simply the best cribbagc game available. It is an excellent program for the cribbage player in search of a worthy opponent as well as for the novice wishing to improve his game. The graphics are superb and assembly language routines provide rapid execution. See the software review in 80 Software Critique. THOUGHT PROVOKERS MANAGEMENT SIMULATOR (Atari, North Star and CP/M only) Price: $19.95 Cassette S23.95 Diskette This program is both an excellent teaching tool as well as a stimulating intellectual game. Based upon similar games played at graduate business schools, each player or team controls a company which man- ufacturers three products. Each player attempts to outperform his competitors by setting selling prices, production volumes, marketing and design expenditures etc. The most successful firm is the one with the highest stock price when the simulation ends. FLIGHT SIMULATOR (Available for all computers) Price: $17.95 Cassette 521. y5 Diskette A realistic and extensive mathematical simulation of take-off. flight and landing. The program utilizes aerodynamic equations and the characteristics of a real airfoil. You can practice instrument approaches and navigation using radials and compass headings. The more advanced (Iyer can also perform loops, half-rolls and similar acrobatic maneuvers. Although this program does not employ graphics, it is ex- citing and very addictive. See the software review in COMPUTRONICS. VALDEZ (Available for all computers) Price: $15.95 Casaette/$t9.95 Diskette VALDEZ is a computer simulation of supertanker navigation in the Prince William Sound/Valdez Narrows region of Alaska. Included in this simulation is a realistic and extensive 256 x 256 element map, portions of which may be viewed using the ship's alphanumeric radar display. The motion of the ship itself is accurately modelled mathematically. The simulation also contains a model for the tidal patterns in the region, as well as other traffic (outgoing tankers and drifting icebergs). Chart your course from the Gulf of Alaska to Valdez Harbor! See the software review in 80 Software Critique. BACKGAMMON 2.0 (Atari, North Star and CP/M only) Price: $14.95 Cassette/$18.95 Diskette This program tests your backgammon skills and will also improve your game. A human can compete against a computer or against another human. The computer can even play itself. Either the human or the computer can double or generate dice rolls. Board positions can be created or saved for replay. BACKGAMMON 2.0 is played in accordance with the official rules of backgammon and is sure to pro- vide many fascinating sessions of backgammon play. CHECKERS 3.0 (PET only) Price: $16.95 Casaette/$20.95 Diskette This is one of the most challenging checkers programs available. It has 10 levels of play and allows the user to change skill levels at any time. Though providing a very tough game at level 4-8, CHECKERS 3.0 is practically unbeatable at levels 9 and 10. CHESS MASTER (North Star and TRS-80 only) Price: $19.95 Cusctte/S23.95 Diskette This complete and very powerful program provides five levels of play. It includes castling, en passant captures and the promotion of pawns. Additionally, the board may be preset before the start of play, permitting the examination of "book" plays. To maximize execution speed, the program is written in assembly language (by SOFTWARE SPECIALISTS of California). Full graphics arc employed in the TRS-80 version, and two widths of alphanumeric display are provided to accommodate North Star users. LEM LANDER <32K Apple Disk only) Price: $16.95 Diskette Pilot your LEM LANDER to a safe landing on any of nine different surfaces ranging from smooth to treacherous. The game paddles are used to control craft attitude and thrust. This is a real-time high res challenge I FOREST FIRE! (Atari only) Price: 516.95 CasMtte/$20.95 Diskette Using excellent graphics and sound effects, this simulation puts you in the middle of a forest fire. Your job is to direct operations to put out the fire while compensating for changes in wind, weather and ter- rain. Not protecting valuable structures can result in startling penalties. Life-like variables are provided to make FOREST FIRE! Very suspenseful and challenging. No two games have the same setting and there are 3 levels of difficulty. NOMINOES JIGSAW (Atari, Apple and TRS-80 only) Price: $16.95 Cassette /S20.9S Diskette A jigsaw puzzle on your computer! Complete the puzzle by selecting your pieces from a table consisting of 60 different shapes. NOMINOES JIGSAW is a virtuoso programming effort. The graphics are superlative and the puzzle will challenge you with its three levels of difficulty. Scoring is based upon the number of guesses taken and by the difficulty of the board set-up. MONARCH (Atari only) Price: $11.95 Cassette/ SI 5. 95 Diskette MONARCH is a fascinating economic simulation requiring you to survive an 8-year term as your na- tion's leader. You determine the amount of acreage devoted to industrial and agricultural use, how much food to distribute to the populace and how much should be spent on pollution control. You will find that all decisions involve a compromise and that it is not easy to make everyone happy. CHOMP-OTHELLO (Atari only) Price: $11.95 Cass*tte/$ 15.95 Diskette CHOMP -OTHELLO? It's really two challenging games in one. CHOMP is similar in concept to NIM; you must bite off part of a cookie, but avoid taking the poisoned portion. OTHELLO is the popular board game set to fully utilize the Atari's graphics capability. It is also very hard to beat! This package will run on a I6K system. DYNACOMP OFFERS THE FOLLOWING Widest variety Guaranteed quality Fastest delivery Friendly customer service Free catalog 24 hour order phone AND MORE... STARTREK 3.2 (Available for ail computers) Price: $11.95 Cassette /$ 15. 95 Diskette This is the classic Startrek simulation, but with several new features. For example, the Klingons now shoot at the Enterprise without warning while also attacking starbases in other quadrants. The Klingons also attack with both light and heavy cruisers and move when shot at I The situation is hectic when the Enterprise is besieged by three heavy cruisers and a starbase S.O.S. is received! The Klingons get evenl See the software reviews in A.N.A.L.O.G., 80 Software Critique and Game Merchandising. BLACK HOLE (Apple only) Price: $14.95 Cassette /SI 8. 95 Diskette This is an exciting graphical simulation of the problems involved in closely observing a black hole with a space probe. The abject is to enter and maintain, for a prescribed time, an orbit close to a small black hole. This is to be achieved without coming so near the anomaly that the tidal stress destroys the probe. Control of the craft is realistically simulated using side jets for rotation and main thrusters for accelera- tion. This program employs Hi-Res graphics and is educational as well as challenging. SPACE TILT (Apple and Atari only) Price: $10.95 Cms*«nc/$14.95 Diskette Use the game paddles to tilt the plane of the TV screen to "roll" a ball into a hole in the screen. Sound simple? Not when the hole gets smaller and smaller! A built-in timer allows you to measure your skill against others in this habit-forming action game. MOVING MAZE (Apple Only) Price: $10.95 Cassetu/S 14.95 Diskette MOVING MAZE employs the games paddles to direct a puck from one side of a maze to the other. However, the maze is dynamically (and randomly) built and is continually being modified. The objec- tive is to cross the maze without touching (or being hit by) a wall. Scoring is by an elapsed time in- dicator, and three levels of play are provided. ALPHA FIGHTER (Atari only) Price: $14.95 Casaette/$1*.95 Diskette Two excellent graphics and action programs in one! ALPHA FIGHTER requires you to destroy the alien starships passing through your sector of the galaxy. ALPHA BASE is in the path of an alien UFO invasion; let five UFO's get by and the game ends. Both games require the joystick and get progressive- ly more difficult the higher you scorel ALPHA FIGHTER will run on 16K systems. THE RINGS OF THE EMPIRE (Atari only) Price: $16.95 Casaette/$20.95 Diskette The empire has developed a new battle station protected by rotating rings of energy. Each time you blast through the rings and destroy the station, the empire develops a new station with more protective rings. This exciting game runs on 16K systems, employs extensive graphics and sound and can be played by one or two players. INTRUDER ALERT (Atari only) Price: S16.95 Cas»elte/$20.95 Diskette This is a fast paced graphics game which places you in the middle of the "Dreadstar" having just stolen its plans. The droids have been alerted and are directed to destroy you at all costs. You must find and enter your ship to escape with the plans. Five levels of difficulty are provided. INTRUDER ALERT re- quires a joystick and will run on 16K systems. GIANT SLALOM (Atari only) Price: $14.95 CassctU/$lS.95 Diskette This real-time action game is guaranteed addictive! Use the joystick to control your path through slalom courses consisting of both open and closed gates, Choose from different levels of difficulty, race against other players or simply take practice runs against the clock . GIANT SLALOM will run on 1 6K systems. TRIPLE BLOCKADE (Atari only) Price: $14.95 Cassette/ Sid. 95 Diskette TRIPLE BLOCKADE is a two-to-three player graphics and sound action game. It is based on the classic video arcade game which millions have enjoyed. Using the Atari joysticks, the object is to direct your blockading line around the screen without running into your opponcnt(s). Although the concept is simple, the combined graphics and sound effect lead to "high anxiety". GAMES PACK I (Available (or all computers) Price: $10.95 CasKtte/$14.95 Diskette GAMES PACK I contains the classic computer games of 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 menu. This collection is worth the price just for the DYNACOMP version of BLACKJACK. GAMES PACK II (Available for all computers) Price: $10.95 Cassctte/$14.95 Diskette GAMES PACK II includes the 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. You will particularly enjoy DYNACOMP's version of CRAZY EIGHTS. Why pay $7.95 or more per program when you can buy a DYNACOMP collection for just $10.95? MOON PROBE (Atari and North Star only) Price: $11.95 Casaette/$15.95 Diskette This is an extremely challenging "lunar lander" program. The user must drop from orbit to land at a predetermined target on the moon's surface. You control the thrust and orientation of your craft plus direct the rate of descent and approach angle. ADVENTURE CRANSTON MANOR ADVENTURE (North Star and CP/M only) Price: $21.95 Diskette At last ! A comprehensive Adventure game for North Star and CP/M systems. CRANSTON MANOR ADVENTURE takes you into mysterious CRANSTON MANOR where you attempt to gather fabulous treasures. Lurking in the manor are wild animals and robots who will not give up the treasures without a fight. The number of rooms is greater and the associated descriptions are much more elaborate than the current popular series of Adventure programs, making this game the top in its class. Play can be stopped at any time and the status stored on diskette. ABOUT DYNACOMP DYNACOMP is a leading distributor of small system software with sales spanning the world (currently in excess of 40 countries). During the past two years we have greatly enlarged the DYNACOMP product line, but have maintained and improved our high level of quality and customer support. The achievement in quality is apparent from our many repeat customers and the software reviews in such publications as COMPUTRONICS, 80 Software Critique and A.N.A.L.O.G. Our customer support is as close as your phone. It is always friendly. The staff is highly trained and always willing to discuss products or give advice. •ATARI, PET, TRS-80, NORTHSTAR, CP/M and IBM are registered tradenames and/or trademarks, "TRsso diskettes are not supplied with dos or basic. Circle 129 on Inquiry card. BUSINESS and UTILITIES SPE SPmoSr (C, 'T 0, * ) P*.:l».HDM. SPELLGUARD a a revolunonary new product which increases the value of your current mrd processina system (WORD- mftJSSKJWS ELECTRIC PENCI1 " TEX ™ EDITOR .1 .„d other.). Written enSrel, in iSSSw bPhLLOUARD rapidly assois the u»;r in elirnin.ti.f ipehini md typographical erron by comparing each word or the ten wins! ■ dictionary (expandable! of over 20,000 of the moil common English wordi. Word, appearing in the ten bui not found in the dictionary are ■■ll.gged" for easy identification and correction. Moit adminiitralive staff familiar with word pro- cessing equipment will be able to use SPELLGUARD™ in only a few minutes. MAIL LIST 2.2 (Apple, Alarl and North Sl»r diskette only) Price: S3« w This program is unmatched in its ability to store a maximum number of addresses on one diskette (minimum of 1 100 per disk- ette, more than 2200 for "double density" syslemsl). Its many features include alphabetic and rip code sorting, label printing merging of file, and a unique keyword seeking routine which retrieves entries by a virtually limitless selection of user defined codes. Mail List 2.2 will even find and delete duplicate entries. A very valuable program! FORM LETTER SYSTEM (FLS) (AUrl, Apple and North Star dbkette only) PHce: S21.M Use FLS to create and edit form letters and address lists. Form letters are produced by automatically inserting each address in- to a predetermined portion of your letter. FLS is completely compatible with MAIL LIST 2.2. which may be used to manaae your address Tiles. FLS and MAIL LIST 2.2 are available as a combined package for S49.93. SOR cJ?7«?"" ,S T W Prtt.iSM.MDUt.* MJK in is * general purpose ion program written in 8080 assembly Language. Thij program will sort sequential data file* generated by NORTH STAR BASIC. Primary and optional secondary key, may be numeric or one to nine character strings SORT1T ii easily used with files generated by DYNACOMP's MAIL LIST program and is very versatile in its capabilities for all other BASIC data Tile sorting. PERSONAL FINANCE SYSTEM (Atari ud North Star only) PrtM- $«.« Dtakrtu PFS is a single diskette, menu -oriented system composed or ten different programs. Besides recording your expenses and lax deductible items, PFS will sort and summarize expenses by payee, and display information on expenditures by any of 26 user defined codes by month or by payee. PFS will even produce monthly bar graphs of your expenses by category! This powerful package requires only one disk drive, minimal memory (24K Atari. 32K North Star) and will store up 10 600 records per disk (and over 1000 records per disk by making a few simple chsnges 10 the programs). You can record checks plus cash expenses so that you can finally set where your money goes and eliminate guesswork and tedious hand calculations. FAMILV BUDGET (Apple only) PH„ : m.w Diskette The FAMILY BUDGET is a very convenient financial record -keeping program. You will be able to keep track of cash and credit expenditures as well as income on a daily basis. You can record tax deductible items and charitable donations. The FAMILY BL'DGET also provides a continuous record of all credit transactions. You can make daily cash and charge entries to any of 21 different expense accounts at well as to J payroll and tax accounts. Data is easily retrieved giving the user complete control over an otherwise complicated (and unorganized!) subject. THE COMMUNICATOR (Atari only) Price: $49.95 Dfakttte This software package contains a menu-driven collection of programs for facilitating efficient two-way communications through a full duplex modem (required for use). In one mode of operation you may connect to a data service (e.g.. The SOURCE or MicroNet) and quickly load data such as stock quotations onto your diskette for later viewing. This greatly re- duces "connect time" and thus the service charge. You may also record the complete contents of a communications session. Additionally, programs written in BASIC, FORTRAN, etc. may be built off-line using the support text editor and later "up- loaded" to another computer, making the Atari a very "nan terminal. Even Atari BASIC programs may be uploaded. Fur- ther, a command file may be built off-line and used later ai controlling input for a time-share system. That is, you can set up your sequence of lime-share commands and programs, and the Atari will transmit them as needed; batch processing. All this adds up to saving both connect time and your time. DYNACOMPalso supplies THE COMMUNICATOR with an Atari B 30 modem for acombined price of 1219.93. The modem is available separately for 1189.95. TEXT EDITOR II (CP/M) Price: S29.95 Diskette/ S3 3. 45 Dkk This is the second release version of DYNACOMP's popular TEXT EDITOR I and contains many new features. With TEXT EDITOR II you may build text files in chunks and assemble them for later display. Blocks of text may be appended, inserted or deleted. Files may be saved on disk/diskette in right justified /centered format to be later printed by either TEXT EDITOR II or the CP/M ED facility, Futher, ASCII CP/M files (including BASIC and assembly language programs) may be read by the editor and processed. In fact, text files can be built using ED and later formatted using TEXT EDITOR II. All in all, TEXT EDITOR II is an inexpensive, easy to use, but very flexible editing system. DOLE (Atari and North Star only) Prke: 5 19.95 This handy program allows North Star and Atari disk users 10 maintain a specialized data base of all files and programs in the slack of disks which invariably accumulates. DFILE is easy to set up and use. It will organize your disks to provide efficient locating of the desired file or program. FINDIT (North Star only) Price: $19.95 This is a three-in-one program which maintains information accessible by keywords of three types: Personal (eg; last name), Commercial (eg: plumbers) and Reference (eg: magazine articles, record albums, etc). In addition to keyword searches, there arc birthday, innivCTiary and appointment searches for the personal records and appointment Marches for ihe commercial re- cords. Reference records are accessed by a single keyword or by cross-referencing two or three keywords. GRAFTX (TRS-M only) Price: S14.95 Casattte/Sli.95 Diskette This unique program allows you to easily create graphics directly from the keyboard. You "draw" your figure using the pro- gram's extensive cursor controls. Once the figure is made, it it automatically appended to your BASIC program as a string var- iable. Draw a "happy face", call it H$ and then print it from your program using PRINT HI! This is a very easy way to create and save graphics. EDUCATION HODGE PODGE (Apple only, 48K Applesoft or Integer BASIC) Price: S19.95 Cassette /S23.W Dtaketic Let HODGE PODGE be your child's baby sitter. Pressing any key on your Apple will result in a different and intriguing "hap- pening" related to the letter or number of the chosen key. The program's graphics, color and sound are a delight for children from ages 1 V. to 9. HODGE PODGE is a n on -intimidating teaching device which brings a new dimension to the use of com- puters in education. TEACHER'S PET I (Available for all computers) Price: $11.95 Cassette/ $15. 95 Diskette This is the first of DYNACOMP's educational packages. Primarily intended for pre-school to grade 3. TEACHER'S PET provides the young student with counting practice, letter-word recognition and three levels of math skill exercises. MORSE CODE TRAINER (TRS-M only) Price: $12.95 Cassette/ $16 .95 Diskette MORSE CODE TRAINER is designed to develop and improve your speed and accuracy in deciphering Morse Code. As such, MCT is an ideal software package for FCC (est practice. The code sound is obtained through the earphone jack of any stan- dard cassette recorder. You may choose the pitch of the tones as well as the word rate. Also, various modes of operation are available including number, punctuation and alphabet tests, as well as the keying of your own message. A very effective way to learn cod el MISCELLANEOUS CRYSTALS (Atari only) Price: $ 9.HCasa*ttc/S13.95 Diskette A unique algorithm randomly produces fascinating graphics displays accompanied with tones which vary as the patterns are built. No two patterns are the same, and the combined effect of the sound and graphics are mesmerizing. CRYSTALS has been used in local stores to demonstrate the sound and color features of the Atari. NORTH STAR SOFTWARE EXCHANGE (NSSE) LIBRARY DYNACOMP now distributes the 23 volume NSSE library. These diskettes each ci standing value for the purchase price. They should be part of every North Star user for details regarding the contents of the NSSE collection. AVAILABILITY DYNACOMP software is supplied with complete documentation containing clear explanations and examples. Unless otherwise specified, all programs will run within 16K program memory space (ATARI requires 24K). Except where noted, programs are avail- able on ATARI, PET. TRS-SO (Level 11) and Apple (Applesoft) cassette and diskette as well as North Star single density (double density compatible) diskette. Additionally, most programs can be obtained on standard (IBM format) 8" CP/M floppy disks for systems running under MBAS1C. STATISTICS and ENGINEERING D,G nVr'tT^ , i™ .95 Diskette MLR is a professional software package for analyzing data sets containing two or more linearly independent variables. Besides performing the basic regression calculation, this program also provides easy to use data entry, storage, retrieval and editing functions. In addition, the user may interrogate the solution by supplying values for the independent variables. The number of variables and data size is limited only by the available memory. REGRESSION I, II and MULTILINEAR REGRESSION may be purchased together for $51.95 (three cassettes) or $63.95 (three diskettes). ANOVA (Available for ail computers) Price: $39.95 Caswtte/S43.95 Dbkette In the past the ANOVA (analysis of variance) procedure has been limited to the large mainframe computers. Now DYNACOMP has brought the power of this method to small systems. For those conversant with ANOVA, the DYNaS?OMP software package includes the 1-way, 2-way and N-way procedures. Also provided are the Yates 2** p factorial designs. For those unfamiliar with ANOVA, do not worry. The accompanying documentation was written in a tutorial fashion (by a pro- fessor in the subject) and serves as an excellent introduction to the subject. Accompanying ANOVA is a support program for building the data base. Included are several convenient features including data editing, deleting and appending. BASIC SCIENTIFIC SUBROUTINES, Volume I (Not available for Atari) DYNACOMP is the exclusive distributor for the software keyed to the popular text fi,4S/C Scientific Subroutines. Volume I by F. Ruckdeschel (see the BYTE/McOraw-HiU advertisement in BYTE magazine, January 1981). These subroutines have been assembled according to chapter. Included with each collection is a menu program which selects and demonstrates each subroutine. Collection #1 : Chapters 2 and 3: Data and function plotting, complex variables Collection HI: Chapter 4: Matrix and vector operations Collection >f3: Chapters 5 and 6: Random number generators, series approximations Price per collection: $14.95 Cassette/S1B.95 Diskette All three collections are available for $39.95 (three cassettes) and $49.95 (three diskettes). Because the text is a vital part of the documentation, BASIC Scientific Subroutines, Volume I is available from DYNACOMP for $19.95 plus 75* postage and handling. ROOTS (Available for all computers) Price $10.95 Cassette/ $14.95 Dbkette In a nutshell, ROOTS simultaneously determines all the zeroes of a polynomial having real coefficients. There is no limit on the degree or the polynomial, and because the procedure is iterative, the accuracy is generally very good. No Initial guesses are required as input, and the calculated roots are substituted back into the polynomial and the residuals displayed. ACTIVE CIRCUIT ANALYSIS (ACAP) (48K Apple only) Price: S13.M/SM.W Dbkette ACAP is the analog circuit designer's answer to LOGIC SIMULATOR. With ACAP you may analyze the response of an ac- tive or passive component circuit (e.g., a transistor amplifier, band pass filter, etc.). The circuit may be probed at equal steps in frequency, and the resulting complex (i.e., real and imaginary) voltages at each component juncture examined. By plotting the magnitude of these voltages, the frequency response of a filter or amplifier may be completely determined with respect to both amplitude and phase. In addition. ACAP prints a statistical analysis of the range of voltage responses which result from tolerance variations in the components. ACAP is « descriptioi of every c sy to learn and use. Simply describe the circuit in terms of the elements and their placement, and execute. Circuit may be saved onto cassette or diskette to be recalled at a later time for execution or editing. ACAP should be part cuit designer's program library. LOGIC SIMULATOR (Apple only; 4SK RAM) Price: $24.95 Qwsette/S2I.W Diskette With LOGIC SIMULATOR you may easily test your complicated digital logic design with respect to given set of inputs to determine how well the circuit will operate. The elements which may be simulated include multiple input AND, OR, NOR, EXOR, EXNOR and NAND gates, as well as inverters, J-K and D flip-flops, and one-shots. The response of the system is available every clock cycle. Inputs may be clocked in with varying clock cycle lengths/displacements and delays may be intro- duced to probe for glitches and race conditions. At the user's option, a timing diagram for any given set of nodes may be plot- ted using HIRES graphics. Save your breadboarding until the circuit is checked by LOGIC SIMULATOR. LOGIC DESIGNER (North Star and CP/M only) Price: $34.95 Dbkette LOGIC DESIGNER is an exceptional Computer Aided Design (CAD) program. With it you may convert a large and compli- cated digitial truth table (the functional specification) into an optimized Boolean logic equation. This equation may then be easily converted into a circuit design using either NAND or AND/OR gates. Operationally, LOGIC DESIGNER is composed of a BASIC program which calls in a machine language routine to reduce execution time. Example: For a 7 variable by 127 line table, the processing time is only two minutes. LOGIC DESIGNER is clearly a fast and powerful tool for building digital cir- cuitry. ORDERING INFORMATION All orders are processed and shipped within 48 hours. Please enclose payment with order and include the appropriate computer in- formation. If paying by VISA or Master Card, include all numbers on card. Shipping aad Handling Charges Within North America: Add $1.50 Outside North America: Add 10*7. (Air Mail) Delivery All orders (excluding books) a 1 sent First Class. I" CP/M Disks Add 12.30 to the listed diskette price for each Microsoft MBASIC or BASIC-80. programs. Dealer discount schedules are available upon request. floppy disk (IBM soft sectored CP/M format). Programs n " CP/M disks is also available on SW" disks. North Star format. e dealer. Write for detailed descriptions of these and other programs from DYNACOMP, Inc. 1427 Monroe Avenue Rochester, New York 14618 24 hour order phone: (716)586-7579 recording Office phone (9AM-5PM EST): (716)442-8960 New York Stale resident, picas* add 7* NV5 sates laa. Players: customer, server, cashier Props: restaurant, table, menu, food, check, payment, tip Actions: 1. Customer goes to restaurant 2. Customer goes to table 3. Server brings menu 4. Customer orders food 5. Server brings food 6. Customer eats food 7. Server brings check 8. Customer leaves tip for server 9. Customer gives payment to cashier 10. Customer leaves restaurant Table 1: A restaurant script for the SAM program. and, therefore, anything that cannot be proved must be false. The world that people deal with in everyday conversa- tions is extensive, complex, and largely unknown and unknowable. To use natural language to converse about the real world, more sophisticated methods are needed. Systems with Knowledge of Ordinary Situations One of the more interesting attempts to deal with or- dinary human situations, in contrast to interfacing with a data base or a model of a microworld, was made by Roger Schank and Robert Abelson, aided by their students at Yale University. Their system, SAM (for Script Applier Mechanism), as described in reference 22, was built to cope with certain kinds of everyday prob- lems. For example, the system is told the following story: John went to a restaurant. He ordered the lamb. He paid the cashier and left the restaurant. Then the system is asked: What did John eat? It might seem trivial for a system to answer that John ate the lamb — but nowhere in the story is this explicitly stated. Nor is it directly deducible from what was said. To understand the story, the system must have both knowledge of what usually happens in restaurants and an ability to apply that knowledge to particular situations. Schank and Abelson encoded SAM's knowledge about everyday situations in formal constructs called scripts. The information contained in a script about restaurants is shown in table 1. It includes a list of players who par- ticipate in the normal routine of a restaurant, a list of props supporting the action, and a sequence of generic actions that characterize what usually happens when a customer visits a restaurant. The information in this script can be used to support a variety of commonsense-reasoning tasks, including a re- ply to the question, "What did John eat?" The processing is as follows: the system identifies "John went to a restaurant" with action 1 from the script. In doing this, John is assigned the role of the customer. The system identifies "He ordered the lamb" with action 4, assigning the role of food to "the lamb." (Notice that with "he" referring to John, the customer is the same in both actions 1 and 4.) "He paid the cashier" is identified with action 9 and "[he] left the restaurant" with action 10. Although not all the actions in the script were explicitly mentioned, it is reasonable (but not strictly necessary) to assume that they happened nonetheless. In particular, ac- tion 6, the customer eating the food, probably did hap- pen. Moreover, because the entities playing the various parts in the script remain constant throughout its enact- ment, the system assumes that, for this particular visit to the restaurant, the customer in each action is John and the food is "the lamb." Therefore, action 6 particularizes to "John ate the lamb," providing the answer to the original question. Information in scripts can be used for more than just answering questions; it can also be used to produce "paraphrases" of a story. For example, SAM can convert the original story: John went to a restaurant. He sat down. He got mad. He left. into the "paraphrase": John was hungry. He decided to go to a restaurant. He went to one. He sat down in a chair. A waiter did not 326 September 1981 © BYTE Publications Inc Circle 387 on inquiry card. 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. 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(214) 669-1758 ystems International Inc. (301) 977-0100 VIRGINIA IASSACHUSETTS Nine Associates, Inc. (703) 273-1803 & S Electronics, Inc. (617) 458-4100 Distributor inquiries welcome! *Registered Trademark of North Atlantic I ndustries. Inc. Circle 303 on inquiry card. AUSTRALIA Mitsui Computer Systems CANADA Computer Markets DENMARK T.M.S. Dataudstyr ENGLAND Northamber Limited FRANCE Gepsi GERMANY Technitron HONG KONG Computerworld Ltd. Hong Kong Equipment ITALY Eltron s.r.l. (030) 55026-41554-44414 NETHERLANDS Compudata Benelux B.V. 31-73-215700 SPAIN 2i Ingenieria Informatica 204-2099 BYTE September 1981 327 02-9299921 416-445-1978 (45) 2-911122 (44) 372-67646 (33) 1-554-9742 49 (89) 692-4141 5-44033 5-453870 Monitoring and Measurement with the Apple II ? w The AI13 sets the Standard of Excellence. Applications: • Scientific Lab Data Acquisition • Home Energy Management • Industrial Process Control • Testing and Quality Control • Monitoring and Logging Data The AI13 plugs into a single slot in Apple II and provides a modular, low cost transformation of the Apple into a precision measurement system. • Economical Modular Approach to Measurement • 16 Independent Input Channels • 12-Bit Precision A/ D Conversion • Software Selectable Input Range • Complete Software Disk Included Interactive Structures has been producing Apple Data systems since 1977, You've heard about one of them: our NASA Spacelab project. Let us show you how to put your Apple to work at a monitoring task. See your Apple Dealer or contact us today. iS Interactive Structures, Inc. 112 Bala Avenue PO Box 404 Bala Cynwyd, PA 19004 'Apple Computer, Inc. go to the table. John became upset. He decided he was going to leave the restaurant. He left it. This restatement is not a true paraphrase because it adds many details based on speculation about what happened. But such an ability to speculate on the basis of knowledge about how our everyday world is structured is the very feature that makes SAM interesting. Much of SAM's knowledge is not about natural language at all, but about our everyday world. SAM demonstrates that understanding natural-language stories about mundane actions requires more than a knowledge of language — it requires a knowledge of the world. The more language is studied, the more apparent it becomes that fluent communication in natural language is a pro- cess of the total intellect. Language, thought, and knowledge are inextricably intertwined. Limitations of SAM SAM's scripts provided one of the first mechanisms in a language processor for dealing with the structured se- quences of actions that make up much of ordinary life, but they suffer from a number of limitations: • Only a single object can serve the role of player or prop. This makes it impossible to handle stories about restaurants with many tables, customers, or servers. The problem of figuring out what the phrase "the customer" refers to becomes trivial because there can be only one customer. • The actions in a script follow a strict linear sequence, making it impossible to deal with alternative possibilities, simultaneous or overlapping actions, or a repetition of actions. • It is difficult to determine which particular script or scripts are appropriate for understanding a given story. The TDUS System The SHRDLU example discussed earlier suggested the potential richness of interactive dialogue in context. The SAM example showed how inference (ie: filling in the blanks regarding what was implied, as well as what was explicitly stated) is essential in understanding natural language. To determine how knowledge-based inference and dialogue management interact, as well as work toward solving a problem of practical value, a group of researchers at SRI International investigated cooperative, task-oriented, man-machine dialogue (see reference 19). They developed a system called TDUS (Task -Oriented Dialogue Understanding System), which had the goal of communicating with a human apprentice about repair operations on electromechanical equipment. The key research problems considered concerned how to encode knowledge about the repair operations and how to follow the context of a dialogue as the apprentice moved from task to task in the course of performing a repair opera- tion. In TDUS, information about how various tasks can be performed is recorded in data structures called pro- cedural networks (see reference 21), which can be viewed 328 September 1981 © BYTE Publications Inc Nobody's better protection than The Marshal in Winchester territory. You got yourself a Winchester disk drive with all that large system power. Great! But trying to utilize your floppy drive for backup just isn't working. And bit-streaming tape cartridge drives offers no practical protection, because the usual need is archival storage and replacement of individual files lost through operator error; but the streamer tape data cannot be reconstructed by separate files easily. Enter The Marshal to your rescue. He's the only match in speed, capacity, and capability for your Winchester. As Thomas S. 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Take this ad to your dealer today, save a heap of money off the regular price, and get the best protection available in Winchester territory. The Marshal from Turnkey Systems Corporation would sure be happy to help you. Call 1-800-327-2848. ©WINSET FINE ADVERTISING Turnkey Systems Corporation 8472 NW 56 Street, Miami, FL 33166 Circle 360 on inquiry card. Figure 6: A procedural net for the process of installing a pump for an air compressor. Figure 7: A procedural net expanding an action referenced in figure 6. A TASK X subtask\_ _ /SUBTASK > . s r \ B , TASK SUBTASK A SUBTASK B TTTT TTTTTTT TTTTTT TTTTT TTTTTTTT TTTTTTT TTTTTTT TTTTTT TTTT TTTTTTTTTTT TTTTTT. A AAAAAAAAAAA AAAAA AAA AAAAAAAA AAAAA AAA AAAAAAAAA AAAAA AAAAA AAAAAAAAA AAAAAA AAAAAAAAAAAAAAA AAAAAAAAA A AAAAA AAA AAAAAAAAA AAAAAAAA AA AAAAAAA AAAA AAAAAAA. TTTT TTTTTT TTTTTTTT TTTTT TTTTT TTTTTTTTTTTT TTTTT TTTTTT. BBBBBB BBBBBB BB BBBBBBBBB BBBB BBBBB BBBBBBBBB BB BBBBBBBB BBBBBBB BBBBBBB BBB BBBBB BBBBBB BBBBB BBBBBBBB BBBBBBBBBBB BBBB BBBB BBBBBBBBB BBBBB. Figure 9: The structure of a task (top) is reflected in the structure of an English dialogue about the task (bottom). When discussing the task, descriptions referring to the overall task (the two paragraphs of the letter T) are interspersed with the paragraphs of text referring to subtask A and subtask B. SECURE WITH BOLTS Figure 8: A procedural net that contains actions repeated in a loop. as generalizations of scripts. Simplified procedural nets are shown in figures 6, 7, and 8. For example, the net of figure 6 indicates how installing a pump for an air com- pressor can be divided into a number of subtasks. The first subtask is to attach the pump to the platform. Once this is done, either the aftercooler elbow or the brace is installed. Once the aftercooler elbow is installed, the aftercooler is installed. Once the brace is installed, the pulley is installed. When both the aftercooler and pulley have been installed, regardless of the order accomplished, the task of installing the pump is complete. Much like a script, the procedural net associates an ac- tion with a number of subactions. However, as opposed to the strict sequence of actions in a script, the procedural net imposes only a partial ordering on subactions. Moreover, subactions are usually associated with pro- cedural nets of their own, which specify in yet greater detail how tasks are divided. For example, the "attach pump" action referred to in figure 6 is described further in figure 7, while the "secure with bolts" action referred to in figure 7 is described further in figure 8. The net of figure 8 contains a loop specifying the repeated procedure of using a wrench to tighten each bolt. As mentioned earlier, a major problem for natural- language processing systems is following the dialogue context and being able to ascertain the referents of noun phrases by taking the context into account. In preparing to build the TDUS system, Barbara Grosz collected a number of dialogues between human experts and appren- tices performing repair tasks (see reference 8). After con- structing procedural nets for the tasks, it was discovered that, as a general rule, the structure of task-oriented dialogues closely follows the structure of the nets representing the division of the task itself. As shown in figure 9, if a task divides into subtasks A and B, the dialogue tends to start with general information about the overall task, then enters a subdialogue about subtask A followed by a subdialogue about subtask B. 330 September 1981 © BYTE Publications Inc ***** •tr-tr-it-ir-tr-tr-tr-ir-tr-tftrir-it-ir-fr-ir'tr'tr-tr-tr-tr-triftr-tr-tr ir-tt-k-tt-tctr-tr-k-tr-tr-tr-tr-tr-ttick-tr-trit -trie 4MHZ, DOUBLE DENSITY,COLOR&B/W GRAPHICS . .THE LNW80 COMPUTER COMPARE THE FEATURES AND PERFORMANCE When you've compared the features of an LNW80 Computer, you'll quickly understand why the LNW80 is the ultimate TRS80 software compatible system. LNW RESEARCH offers the most complete microcomputer system at an outstand- ing low price. We back up our product with an unconventional 6 month warranty and a 10 days full refund policy, less shipping charges. LNW80 Computer $1,450.00 LNH80 Computer w/BSW Monitor & one 5" Drive $1,915.00 AH orders must be prepaid, CA residents please include 6% sales tax. Contact us for shipping charges TRS80 PMC Product of Tandy Corporation. Product of Personal Microcomputer, Inc. FEATURES LNW80 PHC-80** TRS-80* MODEL III PROCESSOR LEVEL II BASIC INTERP. TRS30 MODEL 1 LEVEL II COMPATIBLE 4.0 MHZ YES YES 1 ,8 MHZ YES YES 2.0 MHZ LEVEL III BASIC NO 48K BYTES RAM CASSETTE BAUD RATE FLOPPY DISK CONTROLLER SERIAL RS232 PORT YES 500/1000 SINGLE/ DOUBLE YES YES 500 SINGLE YES YES 500/1500 SINGLE/ DOUBLE YES PRINTER PORT YES YES YES REAL TIME CLOCK YES YES YES 24 X 80 CHARACTERS YES NO NO VIDEO MONITOR YES YES YES UPPER AND LOWER CASE YES OPTIONAL YES REVERSE VIDEO YES NO NO KEYBOARD 63 KEY 53 KEY 53 KEY NUMERIC KEY PAD YES NO YES B/W GRAPHICS, 128 X 48 YES YES YES HI -RESOLUTION B/W GRAPHICS, 480 X 192 YES NO NO HI-RESOLUTIOH COLOR GRAPHICS 128 X 192 IN 8 COLORS (NTSC), YES NO NO HI-RESOLUTION COLOR GRAPHICS 384 X 192 IN 8 COLORS (RGB), OPTIONAL NO NO WARRANTY 6 MONTHS 90 DAYS 90 DAYS TOTAL SYSTEM PRICE $1,915.00 $1,840.00 $2,187.00 LESS MONITOR AND DISK DRIVE $1,450.00 $1,375.00 — LNW80 - BARE PRINTED CIRCUIT BOARD & MANUAL $89.95 The LNW80 - A high-speed color computer totally compatible with the TRS-80*. The LNW80 gives you the edge in satisfying your computation needs in business, scientific and personal computa- tion. With performance of 4 MHz, Z80A CPU, you'll achieve per- formance of over twice the processing speed of a TRS-80*. This means you'll get the performance that is comparable to the most expensive microcomputer with the compatibility to the world's most popular computer (TRS-80*) resulting in the widest soft- ware base. FEATURES: TRS-80 Model 1 Level II Software Compatible High Resolution Graphics . RG8 Output - 384 x 192 in 8 Colors . NTSC Video or RF MOD - 128 x 192 in 8 Colors . Black and White - 480 x 192 4 MHz CPU 500/1000 Baud Cassette Upper and Lower Case 16K Bytes RAM, 12K Bytes ROM Solder Masked and Silkscreened LNW SYSTEM EXPANSION ■ BARE PRINTED CIRCUIT BOARD AND MANUAL $69.95 WITH GOLD CONNECTORS $84.95 The System Expansion will allow you to expand your LNW80, TRS-SO or PHC-80** to a complete computer system that is still totally software compatible with the TRS-80* Model 1 Level II. FEATURES: 32K Bytes Memory 5" Fluppy Controller Serial RS232 20ma I/O Parallel Printer Real Time Clock Screen Printer Bus On Board Power Supply Solder Masked and Silkscreened LNW RESEARCH C OR PORA T ION 2620 WALNUT ST. TUSTIN CA. 92680 LNDoubler&DOS PLUS 3.3D Assembled and Tested w/DOS PLUS 3.3d $175.00 Double-density disk storage for the LNW Research's "System Expan- sion" or the Tandy's "Expansion Interface". The LNDoubler™ is totally software compatible with any double density software generated for the Percom's Doubler***. The LNDoublerTM provides the following outstanding features. . Store up to 350K bytes on a single 5" disk Single and double density data separation Precision write precompensation circuit Software switch between single and double density . Easy plug in installation requiring no etch cuts, jumpers or sol dering . 35, 40, 77, 80 track 5" disk operation . 120 day parts and labor Warranty *** Doubler is a product of Percom Data Company, Inc. DOS PLUS 3. 3D Micro Systems software's double density disk operating system. This operating system contains all the outstanding features of a well developed DOS, with ease in useability. KEYBOARD LNW80 KEYBOARD KIT The Keyboard Kit contains remaining components. a 63 key plus a $84.95 10 key, P.C. board, and CASE LNW80 CASE $84.95 The streamline design of this metal case will house the LNW80, LWN System Expansion, LNH80 Keyboard, power supply and fan, LNDoublerTM, or LNW Data Separator. This kit includes all the hardware to mount all of the above. Add S12.00 for shipping PARTS AVAILABLE FROM LNW RESERARCH . 4116 - 200ns RAM 6 chip set $26.00 8 chip set $33.50 16 chip set $64.00 24 chip set $94.00 32 chip set $124.00 LNW80 "Start up parts set" LNW80-1 $82.00 LNW80 "Video parts set" LNW80-2 $31.00 LNW80 Transformer LNW80-3 $18.00 LNW80 Keyboard cable LNW80-4 $16.00 40 Pin computer to expansion cable $15.00 System Expansion Transformer $19.00 Floppy Controller (FD1771) and UART (TR1602) . . . $30.00 ORDERS & I N F0. NO. 714 - 544 - 5744 SERVICE NO. 714-641-8850 Circle 192 on inquiry card. VISA MASTER CHARGE ACCEPTED UNLESS NOTED ADD $3 FOR SHIPPING Of greater interest is the fact that referential expres- sions tend to refer to objects salient in the current subtask or higher in the task hierarchy, but generally do not refer to objects in sibling subtasks. For example, if in the dialogue of figure 9 a wrench Wi is mentioned in one of the initial utterances before entering subdialogue A, and if a second wrench W 2 is mentioned within subdialogue A, the phrase "the wrench" uttered in subdialogue B more likely refers to Wi than to W 2 — even though W 2 was mentioned more recently. (This is clearly in violation of the rule used by SHRDLU in interaction 5 of listing 3.) In this regard, referential expressions in natural languages tend to follow much the same conventions as do variable references in block-structured programming languages such as ALGOL and Pascal. But the block structure of natural language is not indicated explicitly. TDUS's ability to follow real-world tasks and deal with shifts in both the linguistic and physical context is il- lustrated in the transcript of listing 6, which relates to in- formation contained in the nets of figures 6 through 8. In interaction 1, the apprentice sets the stage by speci- fying what action is being done. This allows TDUS to pinpoint the location in the INST ALL-PUMP net where the apprentice appears to be. In interaction 2, the appren- tice refers to a bolting action and a wrench used in that action. Neither of these is in the top-level representation of the ATTACH-PUMP net, but they both occur in the subordinate net of figure 8. TDUS finds this subnet and determines that no other relevant subnet refers to a dif- A LOGIC ANALYZER FOR $395? YES! OWL LA 1600-A High Speed 16 Channels Interfaces to dual channel scope or Apple computer. • 10 MHZ capture rate • Gold plated connectors and clips • Stores 16 words of 16 bits • Crystal controlled internal clock • 1, 0, X compare word bit selection • Time domain display • Data domain display* • Hex display* Internal and external trigger modes •Oplio: 'ith use of a [i pic computer Comes complete with interconnecting cables ; logic probe clips, diskette for Apple computer, and operating instructions. — Send for FREE brochure — Osborne Wilson Labs. 508 Waterberry Drive Pleasant Hill, California 94523 (415) 932-5489 ferent bolting action. Therefore, the system responds by specifying the wrench mentioned in the net shown in figure 8. In interaction 3, the apprentice asks for the location of the bolts. TDUS does not operate under the closed-world assumption and realizes that there are some things it does not know. Luckily, the user finds the bolts in interaction 4. In interaction 5, the apprentice refers to "the wrench." TDUS determines that the reference is to the wrench men- tioned in interaction 2 and tells the apprentice its loca- tion. In interaction 6, TDUS resolves "it" as pertaining to the same object. In interaction 7, the apprentice tells TDUS that the pump-attaching operation is completed. The system in- fers from this that all the constituent subtasks have also been done. To make sure, it reviews these assumptions for the apprentice. This filling in of intermediate steps is much like that in the SAM examples. In interaction 8, the apprentice poses a logically com- plex question involving the modal concept "should." TDUS's rudimentary notion of "should" interprets the question as asking whether the action mentioned is corn- Listing 6: An actual conversation with the TDUS system. With this system, the computer supervises a task performed by a human apprentice. Human input is shown in boldface. 1 — I AM ATTACHING THE PUMP. OK. 2 — WHICH WRENCH SHOULD I USE TO BOLT IT? USE THE BOX-END WRENCH. 3— WHERE ARE THE BOLTS? I DON'T KNOW. 4— I FOUND THEM. OK. 5— WHERE IS THE WRENCH? THE BOX-END WRENCH IS ON THE TABLE. 6 — I FOUND IT. OK. 7 — I ATTACHED THE PUMP. OK. THE FOLLOWING HAS BEEN ASSUMED: YOU PUT THE PUMP AT THE PLATFORM. YOU BOLTED THE PUMP TO THE PLATFORM WITH THE BOLTS. 8 — SHOULD I INSTALL THE PULLEY NOW? NO. THE NEXT STEP IS: INSTALL THE AFTERCOOLER ELBOW ON THE PUMP OR INSTALL THE BRACE ON THE PUMP. 9 — I'M DOING THE BRACE NOW. OK. "DO" IS ASSUMED TO MEAN: YOU ARE INSTALLING THE BRACE. 10— I'VE DONE IT. OK. "DO" IS ASSUMED TO MEAN: YOU INSTALLED THE BRACE. THE FOLLOWING HAS BEEN ASSUMED: YOU PUT THE BRACE AT THE PUMP. YOU SECURED THE BRACE. 1 1 - I'VE INSTALLED THE PULLEY. OK. 332 September 1981 © BYTE Publications Inc Circle 273 on inquiry card. PrintersPlus ...computers, peripherals, accessories and supplies! APPLE ACCESSORIES LOBO Disk II Add-On . . . 419. SC1PERTERM 80 Col. Card 329. Z80 Soft Card 295. H.S. Serial Card 1 79. COMM. Card 179. HAYES Micromodem 319. PARALLEL Printer Card 1 49. 16K Ram Card 189. GPIB IEEEE-488 Card 259. VISTA A40 Disk II Add-On 349. VISTA A80 Disk II Add-On 529. VISTA A160 Disk II Add-On 799. VISTA A800 Dbl. Den. 8" Con. . . 529. SOFTWARE V1SICALC 119.00 DESKTOP Plan II 169.00 DB MASTER 209.00 ADDRESS Book 40.00 SUPER Text II 125.00 CCA Data Mgmt 85.00 RIBBONS NEC $77.00/Doz. QUME 45.00/Doz. DIABLO 66.00/Doz. ANADEX 1 35.00/6 ea. TRITEL 95.00/Doz. TI/DEC/TTY 45.00/Doz. EPSON 13.95/ea. MPI/Axiom/Base 2 10.00/ea. MAGNETIC MEDIA Premium Quality At Bargain Prices 5'A" Diskettes, all Formats 100% Certified with hub rings, box of 10 Single sided, single density 26.50 Single sided, double density 29.50 Double sided, double density 38.50 8" DISKETTES, ALL FORMATS 100% CERTIFIED Single sided, single density 29.50 SSSD Error Free 34.50 Single sided, double density 39.50 Double sided, double density 49.50 Diablo 630 RO $2,395. Diablo 1640 RO 2,795. Diablo 1 650 RO 3,095. C.ltoh Starwriter RO 1 ,695. Tl 810 RO 1,695. TI820 RO 1,795. Anadex DP9500/9501 1 ,345. Complete Stock of MX-80, MX-80 F/T MX-100 Printers, Graphics Chip Sets Cards and Cables ^i v - NOVELL IMAGE 800 ^ 150 CPS Heavy Duty Matrix 15" wide carriage, expanded, compressed and double density "correspondence quality" printing at 80. 96 and 136 columns, true descenders, underlining, superscripts, subscripts. Up to 3K Buffer, optional character set and graphics option. List $1,395 $1,295.00 PRINT ELEMENTS NEC Thimbles $14.95 Plastic Daisy Wheels for Qume, Diablo. Staiwiiter 6.00 Metal Daisy Wheels 59.00 IBM Selectric Elements 19.00 MODEMS (IDS 103 LP, direct $169. 103 JLP Auto Answer 219. NOVATION CAT, acoustic 1 59. D-CAT, direct 169. Auto Cat 219. Apple Cat 309. LEXICON LX- 1 1 , acoustic 147. HAYES Micromodem, SI 00 349. VIDEO MONITORS Sanyo 9" B/W $ 1 69. NEC 12" Green 229. Amdek 1 2" B/W (Leedex) 1 35. Amdek 1 3" Color 399. VIDEO TERMINALS Ampex Dialog 80 $995. Ampex Dialog 30 795. Televideo 920C 845. Televideo 950 995. Soroc IQ 1 20 795. Soroc IQ 140 1,195. FLOPPY DRIVES 1 — SA 400 Case, power $399. 1 — SA 800/801 Case, power 995. 2— SA 800/801 Case, power 1,495. 2-SA 850/851 Case, power 1 ,995. 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 Apple II I/O Card $ 1 1 0.00 PET/IEEE I/O Card 55.00 Single Sheet Feeder 25.00 QT Cover 25.00 NEC SPINWRITERS 5510/5530 RO $2,595. 5520 KSR 2,895. <* ^ OLYMPIAES100RO Letter quality, Daisy wheel printer/typewriter interfaces to Apple, Atari, NEC, TRS80 and RS232 Serial ports. A truly cost effective letter quality printer that functions as a typewriter. List $1690 $1395.00 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, bank wire 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. Pncing and availability subject to change without notice. Circle 282 on inquiry card. patible with one of the possible next steps in the procedural-net model of the task at hand. Since it is not, TDUS answers in the negative, but goes on to outline the range of acceptable alternatives at this point in the pro- cess. Interaction 9 is of considerable interest in that it con- tains the pro-verb "do." This is a reference to some action involving the apprentice and the brace. But the action is not completely specified. By examining the procedural net, TDUS determines that the likely thing to do with a brace in this context is to install it— so TDUS makes that assumption and reports it to the apprentice. Interaction 10 demonstrates TDUS's ability to com- prehend an extreme case of contextually dependent use of language. Neither "done" nor "it" conveys much infor- mation. Here, "it" refers not to some object in the world, but to an action previously alluded to by the phrase "do- ing the brace." Limitations of TDUS TDUS exhibits a reasonable understanding of the in- terplay among various types of possible real-world ac- tions, and it can follow the evolution of particular instan- tiations of those actions. However, it has little under- standing of the goals and motivations of the apprentice with whom it holds conversations. An exchange well beyond the capability of TDUS is shown in the following actual dialogue between a novice and an expert mechanic: 1. WHAT DO I DO NEXT? REMOVE THE BOLT. 2. HOW DO I GET IT OFF? USE THE RATCHET WRENCH. 3. WHAT'S A RATCHET WRENCH? IT'S ON THE TABLE. Computers may simplify your business, but it isn't always simple to choose one. HAZELTINE 1421 Video Terminal CROMEMCO System 3 QANTEX Series 6000 150 CPS Parallel or Serial Interface ATARI 800 400 As your computer company, Synchro-Sound International will not only offer you a large selection of computer models at discount prices, we'll offer expert guidance on how to choose one. We'll help you determine which computer system will best suit your individual business needs. Whether it's a micro-computer, a printer, a video display terminal, accessories, or even a complete turn-key operation. We'll design it. Configure it. Guarantee it. We also offer a wide range of easy-to-understand software. What's more, we have all the answers after you purchase your computer, too. We'll give you fast delivery. And we have a staff of computer specialists who'll respond quickly to any service you may require. Which all adds up to why we've grown to be one of the largest computer companies in the New York area over the past seven years. So when you decide you need a computer, decide on Synchro-Sound. Our guidance could be almost as priceless as your business. SYNCHRO-SOUND INTERNATIONAL, INC. Where the computers are cold and calculating. But the people aren't. 1550 NORTHERN BOULEVARD, MANHASSET, N.Y. 11 030 TWX 51 0-220-0021 For orders or more information, call: (516) 869-8535 Toll-free: 800-645-3820 334 September 1981 © BYTE Publications Inc Floppy Disk Drives III" lJuul 1 1 uH double-sided double-density drive uses state-of-the-art technology to give you superior data integrity through im- proved disk life, data reliability, and drive serviceability using 5W'media. Qume's independent head load yields wear characteristics far superior to competitive drives. 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Qume's innovative approach to controlling head load dynamics yields wear characteristics far superior to competitive drives. In independent evaluation. Data Trak 8 is setting industry standards 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 efficiency and reduces processing time for end-users. And Data Trak's unique modular design means simplified field servicing for you and your customers. 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Willow, Signal Hill. CA 90806 Call Toll Free (800) 421-7701 AUTHORIZED DISTRIBUTOR FOR QUME CALL FOR PRICE AND DELIVERY (213) 595-6431 or (714) 891-2663 In California Circle 29 on inquiry card. BYTE September 1981 335 Figure 10: A sentence that conveys different information to dif- ferent people. The key point to note here is that, in interaction 3, the response is not a direct answer to the question. If TDUS could answer this question at all, it would likely respond with a dictionary definition such as: "a tool for grasping and turning the head of a bolt, consisting of fixed or ad- justable jaws mounted on a pawl that is engaged by the toothed end of a gripping bar." The person who answered query 3 understood the motivation behind the question. It was asked so the inquirer would know the description of a ratchet wrench, so he could find it, so he could grasp it, and so he could use it to remove the bolts. Understanding the inquirer's hierarchy of goals, the respondent addresses one of the goals closer to the end of the chain (finding the wrench). The cooperative respon- dent saves the inquirer the trouble of taking the step of locating the wrench from its description. Beyond Current Systems Researchers in computational linguistics have only recently begun to appreciate the impact on natural- language communication of what the participants in a conversation know about each other's knowledge, beliefs, plans, and goals. To appreciate the importance of such knowledge, consider the situation illustrated in figure 10. A young mother is giving a birthday party for Junior, and Grandma has come to help. Grandma's task is to light the candles on the cake, so she asks, "When shall I light the candles?" The mother replies, "We'll have the cake as soon as the children wash their hands," which in- forms Grandma that it will be about five minutes. The mother knows that the big-eared kids are listening, so she phrases her response to serve multiple purposes for multi- ple audiences. With her one statement, she tells Grandma when the candles need to be lit and, in a nice, indirect way, tells the children to get their dirty hands washed. She knows that her response to Grandma will serve this purpose because she knows that: • the children want the cake • her response to Grandma will convey to them the infor- mation that all that stands in the way of their getting it is to wash their hands • if they know that all that stands in the way of their get- ting cake is to wash their hands, they will perform the ritual forthwith • it takes them about five minutes to wash their hands Similarly, Grandma now knows that she should light the candles in five minutes because she knows that the mother knows all the circumstances just outlined and that the mother knows Grandma knows that the mother knows it. Thus, Grandma infers that the mother expects her to understand that the children are being told to wash their hands, that they are motivated to do it right away, and the result five minutes later will presumably be washed hands reaching avidly for cake. No system is currently capable of handling language with this level of sophistication, but a number of re- searchers are actively engaged in studying the various problems involved; see references 3, 5, 6, 7, 13, 14, 16, 18, 23, and 27. Much of this work is concerned with the difficulties of interpreting not just what is literally said, but also of establishing the underlying intention. Should this work succeed, systems may be capable of the kind of reasoning indicated in listing 7. The examples of the locked toolbox and the birthday party support a central point: communicating in natural language is an activity of the total intellect. Seen in broad perspective, the use of natural language can be placed in a general framework that seeks to account for all human activity. Within this framework, humans are seen as in- telligent beings motivated by complex sets of goals they seek to fulfill by planning, executing, and monitoring se- quences of actions — some of which are physical, some linguistic. That is, uttering a sentence is just as much an action as taking a step or taking a bath. Whereas the usual purpose of a physical action is to alter the physical world, the usual purpose of a linguistic action is to alter Listing 7: An imaginary conversation with a TDUS-like system showing the possible behavior of a computer system that reacts to human needs in a way not currently possible by existing systems. USER: THE TOOLBOX IS LOCKED. SYSTEM: (WHY IS HE TELLING ME THIS? I ALREADY KNOW THE BOX IS LOCKED.) (I KNOW THE USER NEEDS TO GET IN. PERHAPS HE IS TELLING ME THE BOX IS LOCKED BECAUSE HE BELIEVES I CAN SOMEHOW HELP.) (TO GET IN TAKES A KEY. THE USER KNOWS THIS AND KNOWS I KNOW IT. THE KEY IS IN THE DRAWER. IF THE USER KNEW THIS HE WOULD JUST UNLOCK THE BOX. THEREFORE, HE MUST NOT KNOW IT.) (I CAN MAKE HIM COME TO KNOW IT BY SAYING "THE KEY IS IN THE DRAWER." I AM SUPPOSED TO HELP. I WILL SAY IT.) THE KEY IS IN THE DRAWER. 336 September 1981 © BYTE Publications Inc Into computers? Robotics? Want to get started? Take 6 great books for $9 95 ■■■ (values to $94.70) . . . and get one FREE! All the latest info on software, hardware, applications, and theory at savings up to 75%. Plus, discounts on software, games, cassettes, disks . . . and more! M€®8@9 COOKBOOK ^..aw 1 * 1200 List $16.95 1195 List $12.95 List $9.95 Join now and get How to Build Your Own Working 16-Bit Microcomputer . . . FREE! ! (List $4.95) 7 very good reasons to try The Computer Book Club . . . • Reduced Member Prices. Save up to 75% on books sure to increase your know-how • Satisfaction Guaranteed. 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Interactive Structures, Inc. 112 Bala Avenue PO Box 404 Bala Cynwyd, PA 19004 'Apple Computer, Inc. "Epson America, Inc. 338 September 1981 © BYTE Publications Inc iS the mental states of the hearers. In the latter case, the desired modification may be to add knowledge, change a mood, or establish a new goal for the hearers. A speaker may plan and execute linguistic actions to change some aspect of a hearer's mental state, not as an end in itself, but as part of an overall plan to achieve some more ambitious end. Just as a child might push over the first domino of a long row to make them all tumble in sequence, a lifeguard at the beach may yell "Shark!" at swimmers to set off a chain of reasoning in their minds that will result in a mad dash for the shore, which is the lifeguard's intended mechanism for accomplishing the primary goal of preserving life. Given this view of how language works, it becomes less important to ask what a given utterance means (what does "Shark!" mean?) and more important to ask about the effect it produces. People in advertising have an ex- plicit understanding of this concept, but all of us use it implicitly when we understand the agony conveyed by the string of curses uttered by the handyman who smashes his finger, and when we realize that our friend's question, "Do you know the time?," deserves more than a "yes" or "no" answer. The understanding of poetry can even be cast in this mold. The poet deliberately triggers certain chains of in- ference in readers. Indeed, an important element in the appreciation of poetry is the reader's awareness of the in- terplay among the inference chains followed, the chains followed partway that turn out to be not quite ap- propriate, and the surface meanings of the sentences com- prising the poem itself. To experience this, just consider the title of T S Eliot's poem, "The Love Song of J. Alfred Prufrock." The Nature of Natural-Language Research The previous sections discussed the capabilities and limitations of specific natural-language processing systems. But it must be recognized that these systems are merely spin-offs of the underlying science. In essence, most researchers in this field do not think of themselves as engineers seeking to evolve better natural-language processing systems, but rather as scientists concerned with the following related problems: • identification of sources of knowledge necessary for understanding or generating natural language • discovery or devising of mechanisms for encoding and applying such knowledge in a mechanical device • creation of integration frameworks to control and coor- dinate the application of a variety of knowledge sources Once sources of knowledge have been identified, whole subdisciplines come into being to study the associated bodies of knowledge, their structure, and methods for their computerization. Some of the major knowledge sources are discussed below. Lexical knowledge concerns individual words, the parts of speech they belong to, and their meanings. Syntactic knowledge has to do with the grouping of words into meaningful phrases. 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Z80 Softcard trademark of Microsoft, Inc. knowledge distinguishes between the following two sentences: NAME THE PARTS OF THE PUMP THAT WAS FIXED BY JOE. NAME THE PARTS OF THE PUMP THAT WERE FIXED BY JOE. In particular, it is the syntactic number distinction be- tween WAS and WERE that indicates whether the pump or the parts were fixed. Syntactic ambiguity is a common source of trouble in natural-language processing systems. For example, deci- sions about where to associate the prepositional phrase "on the table" in: PUT THE HAMMER IN THE TOOLBOX ON THE TABLE. can lead to any one of the interpretations: PUT THE HAMMER THAT IS IN THE TOOLBOX ONTO THE TABLE. PUT THE HAMMER INTO THE TOOLBOX THAT IS ON THE TABLE. WHILE YOU STAND ON THE TABLE, PUT THE HAMMER INTO THE TOOLBOX. Compositional semantics is the knowledge of how to compose the literal meaning of large syntactic units from the semantics of their subparts. Its utility is illustrated by the pair of sentences: THE MAN HELD THE NUT (with a wrench). THE WRENCH HELD THE NUT. These two sentences are syntactically identical, but the subject of the first sentence is the agent of the action "hold," whereas the subject of the second is the instru- ment used by the agent. The lexical entry for the verb HOLD indicates that it is used to refer to actions in which an agent (usually a person) using an instrument exerts a force on some physical object. The syntactic subject of the verb might refer either to the agent or the instrument. But the semantics of HOLD indicate that these roles must be filled by objects of mutually disjoint classes of objects. Utilization of this knowledge allows a system to assign the role of agent to THE MAN, but assign the role of in- strument to THE WRENCH. Discourse knowledge concerns the way clues from the current context are used to help interpret a sentence. For example, if we have just been talking about this month's issue of BYTE, the noun phrase "the magazine" in: I'VE ALREADY READ MY COPY OF THE MAGAZINE. is easily understood in this context as referring to this month's issue of BYTE. Yet, we often have personal knowledge of hundreds of issues of various magazines. 340 September 1981 © BYTE Publications Inc Circle 332 on inquiry card. Micro computer software company gets macro results. "Software is the hottest segment of the personal computer industry. After all, it's the software that solves problems. And Business Week has precisely the type of readers who are looking for solutions to the kinds of problems we solve. Top and middle management of corpora- tions. That's why right from the start we committed a substantial portion of our marketing budget to advertise in Business Week. And we're very pleased with the results. Since our first insertion, our monthly sales have more than doubled." James M. Dow, President Microcom, Inc. When Microcom began in 1980, the Boston-based manufacturer of personal com- puter software wanted to spread the word to corporate Circle 45 on inquiry card. managers about its first product — an electronic mail pack- age for Apple™ computers called Micro-Courier™ Not only to managers who already have Apples,™ but to the fast- growing market of managers in corporations who are thinking of buying personal computers to help them and their staffs do a better job. For Microcom's Jim Dow, Business Week brought his market into focus. Business Week has a take-action audi- ence of over 6 million cor- porate decision makers. And they look to Business Week to keep them informed on com- puter developments. Business Week is the only general busi- ness publication with an entire editorial section, Information Processing, covering events and trends in the computer industry Every week. As Microcom found out, one of the best times to link up with Business Week is right at square one. But for small companies or large companies, Business Week gets big-time advertising results. Call your nearest Business Week representative today. BusinessWeek Source: MR1 (Spring, '81)/Pub, est. BYTE September 1981 341 DB ACCESS PRONOUNS ELLIPSIS ENHANCEMENT BY DECOMPOSITION CAPABILITY RESOLUTION OF DEFINITELY-DETERMINED NOUN PHRASES IN CONTEXT NONLITERAL INTERPRETATION Figure 11: A graph of capability versus cost for systems that can handle natural-language queries. The ability to pick the one of current interest is based on specific knowledge of the current situation. World knowledge is concerned with information about how the world is currently configured and about physical constraints upon possible configurations. For example, we understand: PRESIDENT REAGAN FLEW TO CALIFORNIA. to mean that he was flown to California as a passenger in an airplane. Had the sentence been about a bird, we might have taken the sentence to mean that the bird did the flying. As an example of how knowledge about the current physical situation can be of aid in understanding sentences, consider again the sentence: PUT THE HAMMER IN THE TOOLBOX ON THE TABLE. discussed in the earlier paragraph on syntax. If we know that the hammer is currently in a toolbox on the floor, the only interpretation of the sentence is to lift the hammer out of the toolbox and place it onto the table. The other interpretations are ruled out because they are impossible in the current state of the world. Knowledge of mental states relates to comprehending the knowledge and goals of other participants in a dialogue. The use of such knowledge is shown in the locked-toolbox example in listing 7. Cost as a Function of Capability The preceding sections sketched a spectrum of natural- language processing capabilities — ranging from isolated questions about the data in conventional data bases, through the literal interpretation of utterances in dynamic contexts, to an understanding of the underlying goals and mental states of participants in a dialogue. As would be expected, progression through this spectrum entails rapidly escalating costs in two areas: the research and programming effort required to reach a particular level of capability, and the computing resources (measured in the number of machine instructions that must be executed and the memory requirements) needed to function at a given level. This situation is illustrated graphically in figure 11, which plots cost as a function of system capability. Although the diagram shows a sharp rise in cost with in- creased capability, the situation is probably even more dramatic than indicated, and the cost scale might best be interpreted as being logarithmic. The capability dimension has been separated into three major regions by two dividing lines. It appears that capabilities beyond (to the right of) the leftmost line re- quire systems with explicit models of concrete objects in the world, the relationships among them, and the types of processes that can alter those relationships. The more advanced capabilities beyond the rightmost line require further enhancements for modeling such things as the mental states of dialogue participants. Figure 12 repeats the curve of figure 11, but also shows curves for developing three kinds of systems. Systems on curve A are built without the use of explicit models. They cover most of the principal linguistic phenomena needed for accessing conventional data bases and, up to the point at which curve A intersects curve B, can be constructed and operated more economically than other types of systems. As the need for world models increases, at- 342 September 1981 © BYTE Publications Inc Zl (1 |fi (1 o A Powerful New Language . In interaction 2, the user seeks information about what LADDER would accept as a valid expression for a < PORT > . This is a very in- teresting question because it is not about the data in the data base, but rather a question about the language- processing system itself. LADDER can process questions about a variety of knowledge sources, including special routines that inspect its own internal information about the linguistic constructions it can accept. Using one of these special routines, LADDER produces a list of possi- ble expressions for , including the expression NEW YORK, which the user identifies as being what is meant by NY. At this point, the user could rephrase the question by using NEW YORK in place of NY. But it is important for natural-language processing systems to accommodate the linguistic constructions their users are comfortable with — to accept inputs in the users' own terms, rather than force the users to master the system's terms. In par- ticular, the learning of synonyms is relatively inexpensive computationally and quite helpful to users. In interaction 3, the user types a statement in English to tell LADDER that NY is a synonym for NEW YORK. Then, in interac- tion 4, the user asks that interaction 2 be tried again. This 346 September 1981 © BYTE Publications Inc Circle 314 on inquiry card. SAVE SALE SAVE SALE SAVE SALE SAVE Circle 135 on inquiry card. 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A Copy of the Radio Shack 90 day Limited Warranty can be obtained Free upon specific written re- quest to the Electronics Dept. of our Cairo, Georgia Retail Store which is an Authorized Sales Center for Radio Shack Merchan- dise. Store #A30I Circle 223 on inquiry card. BYTE September 1981 347 i.I'Iiik in Metro Keypud/Disnicry ■l. Add Ural B in sum a Add 4k HAM 5. Add two S10Q hoards i Ki (i. Add you own custom i BUtfS (nnildlvpinfi (IFROj 7. Connotf lerminal FOR ONLY $129.95 Learn Computing [ From The Ground Up Build a Computer kit that grows with you, and can expand to 64k RAM, Microsoft BASIC, Text Edi- tor/Assembler, Word Processor, Floppy Disks and more. EXPLORER/85 Hern's ihe low cosl way to learn the fundamentals of com- puting, ihc all-importanl basics you'll need more and more as you advance in compuler skills. For jusl 5129.95 you get the advanced -design Explorer/85 mo I her board, with all Ihc features you need to learn how to write and use programs. And it can grow into a system thai is a match for any personal computer on the market. Look at Ihese features: flOflS Central Processing Unit. Ihe microprocessor "heart'' of Ihe Explorer/85, (loin the millions who will buy and use Ihe 8080/8085 this year alone!). . .Four 8 -hilpfusonee-bilinpuI/oulpuJporlsfrom which you can input and output your programs, as well as control cxlerior switches, relays, lights, etc. . a cassette interface thai lets you store and reload programs you've learned to write . . . deluxe 2,000 byte operating system /monitor makes it easy lo learn computing in several important ways: • ll allows simpler, faster writ- ing and entering of programs • It permits access by you lo all parls of the system so you can check on Ihe status of any poinl in the program • tl allows tracing each pro- gram step by step, with provision for displaying all Ihe contents of the CPU (registers, flags, etc.) • ... and it does much more! 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The assem- bler performs the clerical lask of translating symbolic code into Ihe computer-readable objeel coda The editor/ assembler program is available either in cassette or a ROM version □ Editor/Assembler (Cassette version; requires Level "B" and 8k (min.) of RAM — we suggesl Iflk "|AWS" — see above) . . $59.95 plus $2 P&L* D Editor/Assembler (ROM version, supplied on an SlOO card; requires Level B and 4k RAM (min.) — we suggesl either Level D or 16k "|AWS") . . . $99.95 plus $2 P&L* 8" FLOPPY DISK — A remarkable "building block." Add our 8" floppy disk when you need faster operation. more convenient program storage, perhaps a business ap- plication, and access to Ihe literally thousands of programs and program languages available today, You simply plug them inlo your Explorer/flS disk system — it accepts all IBM-formatted CP/M programs. D 8" Floppy Disk Drive . . . $499.95 plus $12 P&l.* □ Floppy Controller Card . . . $199.95 plus S2 P&L* □ Disk Drive Cabinet & Power Supply . . . $6ft.9!i plus $3 P&l.* D Drive Cables (set up for two drives) . . . $25.00 plus $1.50 P&L* □ CP/M 2.2 Disk Operating System: includes Text Ed it or/ Assembler, dynamic debugger, and other features lhat give your Explorer/85 access lo thousands of existing C/VM- based programs . . $150.00 postpaid. NEED A POWER SUPPLY? Consider our API ll can supply all the power you need for a fully expanded Ex- Plorer/85 (note: disk drives have theirown power supply). lus Ihe AP-1 fils neatly into Ihe attractive Explorer sleel cabinet (sec below) D AP-1 Power Supply kit (8V # 5 amps) in deluxe steel cabinel . . . $39.95 plus $2 P&L* NEED A TERMINAL? We offer you choices: Ihe least ex- pensive one is our Hex Keypad/Display kit that dis- plays Ihe information on a calculator-type screen. 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B floppy disk controller, one CDC tl" disk-drive, two-drive cable, two SlOO connectors: just add your own power supplies, cabinets and hardware . D (Reg. $1065,00) SPECIAL 5999.95 plus $13 P&l * ... (J :12k Starter Svslem. $1045.95 plus $13 P&I.* □ 4fik Starlet Svslem, $1095.95 plus SKI P&I* D B4k Starter System. 51145.95 plus $13 P&I.' □ Add lo any of above Explorer steel cabinet. AP-1 five amp. power supply. Level C with two SlOO connectors, disk drive cabinet and power supply, two suh-D connec- tors for connecting your printer and terminal . . . (Reg. $225.95) SPECIAL $199.95 plus $13 P&l.' D Complete 04k Syslem. Wired ft Tested . . , $1650.00 plus $28 P&L* D Special! Complete Business Software Pak (Save $625.1101 — Includes CP/M 2.2 Microsoft BASIC, General Ledger, Accounts Rwieivable. Accounts Payable. Payroll Package . . . (Reg. $1325) SPECIAL $699.95 postpaid. Conlinental Credit Card Buyers Outside Connecticut: t TO ORDER Call Toll Free: 800-243-7428 ; To Order From Connecticut, or For Technical ' Assistance, call (203) 354-9375 i j^ (Clip unit mtu'l entire octyTlf l SEND ME THE ITEMS CHECKED ABOVE ] Total Enclosed (Conn. Residents adil sales tax): 5 i Paid by: I I □ Personal Check □ Cashiers Check/Money Order I I D VISA D MASTER CARD (Bank No. - I ! iSfc NETRONICSResearch&DevelopmentLtd.: i?. 3 . 3 . Litchfield^Roadj New Milford, CT 06776 mmmmmm \ Listing 8: system. Another actual conversation with the LADDER I — How far is the kennedy from the port of NY? Trying Ellipsis: ELLIPSIS HAS FAILED The parser does not expect the word "NY" to follow "HOW FAR IS THE KENNEDY FROM THE PORT OF" Options for next word of symbol are: 2— What is a ? PARSED! "" may be any sequence of words following one of the pat- terns: => CAPETOWN = > NEW YORK = > NEW ORLEANS [etc.] 3— Define NY like New York. PARSED! NY 4 — redo 2 [i.e., How far is the Kennedy from the port of NY?] PARSED! (GCDIST 1974) 5 — Ql Kennedy [System gives syntax error.] 6 — Let "Ql kennedy" be a paraphrase of "what is the position, fuel status and homeport of the Kennedy" PARSED! => Ql 7 — ql kennedy PARSED! (POSITION 4000N0600E PCFUEL 90 PORT MAYPORT) 8 — American subs in the North Atlantic Trying Ellipsis: Ql AMERICAN SUBS IN THE NORTH ATLANTIC SHIP POSITION PCFUEL PORT STURGEON 3700N7600W 100 NORFOLK WHALE 3750N7700W 100 NORFOLK ASPRO 3000N3000W 100 NORFOLK [etc.] 9 — Let "show the forcestatus of the Kitty Hawk" be like "Display the employment and readiness condition of the Kitty Hawk. Print her destination. List ships in her organization." PARSED! [New production added to system.] 10 — show the forcestatus of Kennedy PARSED! [questions defined in 9 for Kitty Hawk are answered for the Kennedy.] I I — Define "Kennedy no nagasa wa ikura desuka" like "what is the length of the kennedy." PARSED! [Production added to system.] 12 — Fox no nagasa wa ikura desuka? PARSED! LEN = 547 time, using the newly defined synonym, LADDER suc- cessfully interprets the question and produces the answer that the great-circle distance (labeled as GCDIST) from the Kennedy to New York is 1974 miles. It is worth noting that LADDER must do more to answer queries 2 and 4 than merely retrieve information from a data base. Only the positions of ports and ships are stored in the data base — not the distances between them. Thus, LADDER interfaces not only with the data base, but also with programs that make calculations based on data-base information. Some of these are not trivial. For example, to find how long it would take a ship 348 September 1981 © BYTE Publications Inc Circle 143 on inquiry card. Circle 138 on inquiry card. 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. /[FOR ETHOUGHT V^PRODUCTS 87070 Dukhobar Road, Eugene, Oregon 97402 (503) 485-8575 NEVADA \ I a $14995 DISKETTE AND MANUAL • Uses CP/M or MP/M operat- ing system to work with TRS-80, Apple's with softcard, North Star, Superbrain, Micropolls, and many other microcomputers. Needs a minimum of 16K of RAM. Uses single density 8" or 5V»" diskette. I o ELUS COMPUTING SOFTWARE TECHNOLOGY Edition II of Nevada COBOL, subset of ANSI-74, features: Copy statement for library handling. CALL.. .USING. ..CANCEL. • PERFORM. ..THRU. ..TIMES... UNTIL. . . Paragraph or section names. • IF.. .NEXT SENTENCE. ..ELSE... NEXT SENTENCE AND/OR < = >N0T. • GO TO. ..DEPENDING ON. • Unique easily understood diagnostic error messages. • Interactive ACCEPT/DISPLAY... • RELATIVE (random) access files. • Sequential files both fixed and variable length. • DISPLAY, 16-bit binary or packed decimal (C0MP-3) data types with up to 18-digit accuracy. • INSPECT.. .TALLYING... REPLACING. • ADD, SUBTRACT, MULTIPLY, DIVIDE, GIVING, ROUNDED, ON SIZE ERROR. • Generates optimized 8080 machine language at up to 500 statements per minute. WE WELCOME C.O.D'S 600 41st Avenue San Francisco, CA 94121 IT ^^^^2 (415) 751-1522. CP/M. MP/M and TRS-80 are registered TM's of Digital Research and Tandy Corporation. MICR0STAT Microstat is an advanced statistics package designed lor use in research, education and industry. Microstat is a file-oriented statistics package with a Data Management Subsystem (DMS) that creates the data files plus the ability to: edit, list, destroy, delete cases, augment, sort, rank-order, lag, move, merge and transform the data. The data transforms include: add, subtract, multiply, divide, reciprocal, log, natural log and antilog, exponen- tial, linear transformations plus adding any number of variables to create new variables. Once the file is created, it can be used to produce: Descriptive statistics, Hypothesis tests (mean and proportion), AN OVA (one-way, two-way and random blocks), Scatterplots, Frequency distributions. Correlation analysis, Simple and Multiple regression, Time Series, Nonparametric tests (11 of them), Crosstabs and Chi-square, Factorials, Permutations. Combinations, and 8 Probability distributions. The price of Microstat is $250.00 and the user's manual is available for $20.00 and includes sample printouts. Since the printouts reference stand- ard statistics textbooks and journal articles, you can compare the accuracy of Microstat to results produced on much larger systems. No other statistics package seems to have the confidence to do that ... at any price. Microstat is available for the North Star DOS and Basic, Microsoft's Basic-80™ (5.03 or later) and Compiler Systems' CBasic2™. Please specify 8" SD (soft-sectored) or North Star 5V<" disk when ordering. ECOSOFT P.O. Box 68602 Indianapolis, IN 46268 (317) 283-8883 E;ter charge] INTERCHANGE If you use the CP/M™ operating system, life just got a whole lot easier for you. Interchange is a Z-80™ assembly language program that gives you all of the features that PIP doesn't, plus several unique features. Some of the features of Interchange include: DIR, in the usual fashion, plus listing all files excluding those with a specified character. Read/write status is also given. ERA, as usual plus exclusive erases. In addition, a "Q" switch can be used to query on each erase, a "W" allows erases of R/0 files without query (normally you are queried), and an "R" switch if system files are to be included. LIST permits printer listings with formatting controlled by TAB, WIDTH, LINES and WRAP. If you are using the QT Systems Clock Board, listings include the date and time. COPY including exclusive copies and the optional "Q", "W" and "R" switches plus an "E" switch that queries if the file already exists. It also allows for changing disks in the middle of a copy if either the disk or directory become full. It automatically verifies copies. STAT, with ambiguous, unambiguous and exclusive listings. It produces an alphabetized listing and includes each file length, total directory entries and space used and unused. Other commands include RENAME (including ambiguous), HELP, START, END, CLEAR. RESET, DATE, TIME. TAB. WIDTH. LINES. WRAP. QT. SETIT and TYPE. Once you've used Interchange, we doubt that you'll ever use PIP again. The price of Interchange is $59.95 and the manual is available for $10.00. Orders must be accompanied with your CP/M serial number. Interchange is recommended for a 32K or larger system and will not run with an 8080 CPU. At the present time, only User is supported. CBesic2 is a registered trademark of Compiler Systems. CP/M is a registered trademark of Digital Research. Circle 131 on inquiry card. BYTE September 1981 349 to reach a given location, LADDER cannot simply divide the great-circle distance by the cruising speed of the ship, because the shortest path between two points on earth often crosses land masses. So LADDER computes routes that avoid land masses, which requires a knowledge of world geography. Interactions 4 through 8 illustrate LADDER'S ability to learn new syntactic constructions, as well as synonyms. Suppose a user has certain questions to ask repeatedly about different ships. Natural language is ideal for one- time questions, but a shorthand version would be useful for those used repeatedly. If, as in interaction 5, the user asks a shorthand question such as "Ql Kennedy?", a syn- tax error will occur. However, the user can easily tell LADDER, by giving an example in English, how a new shorthand is to be interpreted. This is done in interaction 6. In response to this request, LADDER creates a new production rule that matches inputs that start with "Ql" and end with any expression designating a < SHIP > . In interaction 7, this newly defined construction is used to ask for information about the Kennedy. In interaction 8, to obtain the same information for all the American subs in the North Atlantic, just "American subs in the North Atlantic" need be typed. LADDER'S elliptical- processing routine, operating on the newly defined con- struction just as on the standard ones, fills in the rest. Because there are multiple answers to the question, a table is produced to display the data retrieved. In interaction 9, the user tells LADDER to make a cer- tain input sequence equivalent to not just one but a whole series of questions. It is as if the user were writing small programs in English, using English pronouns for formal parameters. In interaction 10, the new construction is used, but with a different ship than the one used to define the construction. As an extreme example of this ability to accommodate the user-defined constructions, in interaction 11, the user tells LADDER a Japanese paraphrase of the English ques- tion, "What is the length of the Kennedy?" In interaction 12, the user poses this question about the Fox, rather than the Kennedy, entirely in Japanese. The language-processing capabilities demonstrated in listings 3 and 8, while far from those possessed by a fluent user of natural language, seem quite adequate for a wide range of practical applications. This technology, using the language INTERLISP, is available today in a large computing environment. It requires approximately 500 milliseconds to process a query — far less than the time needed to retrieve information from a large data base. With proven algorithms and data structures in hand, it is now essentially an engineering task to implement this technology on smaller machines in widely available pro- gramming languages. Such engineering will require a considerable effort, but the path of development appears to be clear of major theoretical obstacles. One of the practical problems currently limiting the use of natural-language processing systems for accessing data bases is the lack of trained people and good support tools for creating the knowledge structures needed for each new data base. In laboratory systems, researchers have manually compiled bodies of knowledge such as informa- tion about the vocabulary employed in a particular ap- plication or about the logical structure of particular data bases. Work has already begun on new methodologies to automate this task or even make it entirely unnecessary (see references 9, 15, and 25). Conclusion Considerably more research in computational linguistics will be required before mechanical devices can be created that are fluent in the use of natural language. However, current research efforts are shedding new light on the types of knowledge required for communication in human languages, as well as on prospective mechanisms for encoding and applying that knowledge in computers. These efforts are showing that language use is not an isolated intellectual activity; it also involves our basic facilities for commonsense reasoning and planning. A computer system fluent in a natural language will be a genuinely intelligent machine. Although the fluent use of natural language by machines remains a long-term goal, a number of practical mechanisms have been developed to deal with significant fragments of language in specialized application areas. For many applications, an ability to communicate within such fragments is both sufficient for the task at hand and McGraw-Hill Bookstore An End-User's Guide to Data Base Other James Martin Books on Data Base Systems: Principles of Data-Base Management Computer Data-Base Organization, 2nd Ed. Security, Accuracy, and Pri- vacy in Computer Systems Design of Man-Computer Dialogues Managing the Data-Base Environment The Most Referred-to Author of Computer Books Written expressly for those with little or no knowledge of computers or software Success of data base operations is dependent on the end-user- and here are the principles that should be understood by all who will be affected! 144 pp. Prentice- Hall. $21.95. James Martin- m Please print clearly. McGraw-Hill Bookstore BY9 1221 Avenue of the Americas N.Y, N.Y 10020 Please send me copies of An End-User's Guide to Data Base by James Martin at $21.95. MasterCard Visa AmerExp Expires. Account No Name Address City .State. -Zip- Add sales tax plus $2.50 postage, handling 350 September 1981 © BYTE Publications Inc Circle 208 on Inquiry card. Circle 347 on Inquiry card. Circle 109 on Inquiry card. 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(Digital Research MP/M) • High level language processors including Fortran - Basic - Pascal - Cobol. • Complete Turn-key system for ease of operation & learning! For Additional Information Contact: MAPS, Commercial Products Division of: DIGIAC CORPORATION 1 75 Engineers Road, Smithtown, N.y. 1 1 787 Phone: (516) 273-8600 MP/M is a trademark of Digital Research Corp. GRAPHIC SOFTWARE FOR MICROCOMPUTERS by B.J. Korites, PhD - a self-teaching guide that will showyou how to write graphics software on your microcomputer. Theory and program listings presented side by side. Contains 61 programs for 2 and 3 dimensional graphics, isometric and perspective transformations, scaling, stretching, clipping, intersections, shading, tablet software, hidden line removal, dynamicsimulation, applications to engineering, science and business. Practice problems for classroom use. Covers elementary to advanced concepts. Perfect for professionals, students and software developers. All programs in BASIC, written on the Apple II Plus 48K but convertible to other systems. Book with program listings - $19.95 Disk of programs - $18.95 Add S2 per item shipping in US and Canada. $12 elsewhere. Add $5 lor UPS. visa/mastercharge accepted. Call (617)934-0445 for faster delivery. KERN PUBLICATIONS • PO Box 1029A • Duxbury, MA 02332 (617)934-0445 Circle 184 on inquiry card. BYTE September 1981 351 How to Get More Information About Natural- Language Processing The Association for Computational Linguistics is a profes- sional society for people interested in this subject; it publishes the American Journal of Computational Linguistics. For information, contact Donald Walker, SRI In- ternational, Menlo Park CA 94025. Readers are also referred to the American Association for Artificial Intelligence (con- tact Bruce Buchanan, Computer Science Department, Stan- ford University, Stanford CA 94305), and the Cognitive Science Society, which publishes the journal Cognitive Science (contact Donald Norman, Center for Human Infor- mation Processing, C-009, University of California at San Diego, La folia CA 92093). clearly preferable to forcing users to learn machine- oriented languages. In coming years, we expect to see natural-language processing employed in an increasing number of practical applications, enabling more and more people to interact directly and effectively with com- puter systems. ■ Acknowledgments We wish to express our thanks to SRI International and Machine In- telligence Corporation for supporting the preparation of this article, and acknowledge the helpful critiques of early drafts that were provided by Barbara Grosz, Norman Haas, Robert Moore, lane Robinson, and Donald Walker. Listing 5 and figures 3 through 5 were adapted from Understanding Natural Language by Terry Winograd (Academic Press, 1972) with permission of the publisher and author. References 1. Appelt, D E. "A Planner for Reasoning about Knowledge and Ac- tion." Proceedings of the First Annual National Conference on Ar- tificial Intelligence, August 1980, pages 235 through 239. 2. Biermann, A B. "Approaches to Automatic Programming." Ad- vances in Computers, volume 15, 1976, pages 1 through 63. 3. Bruce, B. "Pragmatics in Speech Understanding." Advance Papers of the Fourth International Joint Conference on Artificial Intelligence, 1975, pages 461 through 467. 4. Burton, R R. "Semantic Grammar: An Engineering Technique for Constructing Natural Language Understanding Systems." BBN Report 3453, Bolt, Beranek, and Newman Inc, Cambridge MA, December 1976. 5. Carbonell, J. "Politics." Inside Computer Understanding (reference 23), pages 259 through 317. 6. Cohen, P R and C R Perrault. "Elements of a Plan Based Theory of Speech Acts." Cognitive Science, volume 3, number 3, 1979, pages 177 through 212. 7. Grosz, B J. "Utterance and Objective: Issues in Natural Language Communication." Sixth International Joint Conference on Ar- tificial Intelligence, 1979, pages 1067 through 1076; also in Al Magazine, volume 1, number 1, 1980, pages 11 through 20. 8. Grosz, B J. "Focusing and Description in Natural Language Dialogues." Elements of Discourse Understanding: Proceedings of a Workshop on Computational Aspects of Linguistic Structure and Discourse Setting, A K Joshi, I A Sag, and B L Webber (editors), Cambridge: Cambridge University Press, 1981. 9. Haas, N and G G Hendrix. "An Approach to Acquiring and Apply- ing Knowledge." Proceedings of the First Annual National Con- ference on Artificial Intelligence, August 1 980, pages 235 through 239. 10. Harris, L R. "User Oriented Data Base Query with the ROBOT Natural Language Query System." Proceedings of the Third Inter- national Conference on Very Large Data Bases, October 1977. 11. Hendrix, G G. "The LIFER Manual: A Guide to Building Practical Natural Language Interfaces." Al Center Technical Note 138, SRI International, Menlo Park CA, February 1977. 12. Hendrix, G G, E D Sacerdoti, D Sagalowicz, and J Slocum. "Developing a Natural Language Interface to Complex Data." Association for Computing Machinery Transactions on Database Systems, volume 3, number 2, June 1978. 13.Hobbs, J R and D A Evans. "Conversation as Planned Behavior." Al Center Technical Note 203, SRI International, Menlo Park CA, 1979. 14. Kaplan, S J. "Cooperative Responses from a Portable Natural Language Data Base Query System." PhD Dissertation, Universi- ty of Pennsylvania, Philadelphia, 1979. 15. Lewis, W H. "TED: A Transportable English Datamanager." Pro- ceedings of the Principal Investigators' Meeting of the ACCAT Program, October 1979. 16. Mann, W. "Toward a Speech Act Theory for Natural Language Processing." ISI/RR-79-75, USC/lnformation Sciences Institute, Marina del Rey CA, 1980. 17. Moore, RC. "Reasoning About Knowledge and Action." Al Center Technical Note 191, SRI International, Menlo Park CA, October 1980. 18. Perrault, C R and J F Allen. "A Plan-Based Analysis of Indirect Speech Acts." American Journal of Computational Linguistics, volume 6, number 3-4, July-December 1980, pages 167 through 182. 19. Robinson, A E, et al. "Interpreting Natural-Language Utterances in Dialog About Tasks." Al Center Technical Note 210, SRI Inter- national, Menlo Park CA, 1980. 20. Robinson, J J. "DIAGRAM: A Grammar for Dialogues." Al Center Technical Note 205, SRI International, Menlo Park CA, February 1980. 21. Sacerdoti, E D. A Structure for Plans and Behavior. New York: Elsevier North-Holland, 1977. 22.Schank, R and R Abelson. Scripts, Plans, Goals, and Understand- ing. Hillsdale NJ: Lawrence Erlbaum, 1977. 23.Schank, R and C Riesbeck. Inside Computer Understanding. Hillsdale NJ: Lawrence Erlbaum, 1981. 24.Templeton, M. "EUFID: A Friendly and Flexible Frontend for Data Management Systems." Proceedings of the 1979 National Con- ference of the Association for Computational Linguistics, August 1979. 25. Thompson, F B and B H Thompson. "Practical Natural Language Processing: The REL System as Prototype." Advances in Com- puters 13, M Rubinoff and M C Yovits (editors), New York: Academic Press, 1975. 26. Waltz, D. "Natural Language Access to a Large Data Base: An Engineering Approach." Proceedings of the Fourth International Joint Conference on Artificial Intelligence, September 1975, pages 868 through 872. 27.Wilensky, R. "Meta-Planning." Proceedings of the First Annual National Conference on Artificial Intelligence, 1980, pages 334 through 336. 28.Wilks, Y. "Natural Language Understanding Systems within the Al Paradigm: A Survey and Some Comparisons." Linguistic Struc- tures Processing, A Zamplolli (editor), Amsterdam: North-Holland, 1977, pages 341 through 398. 29. Winograd, T. Understanding Natural Language. New York: Academic Press, 1972. 30. Woods, W A. "Transition Network Grammars for Natural Language Analysis." Communications of the Association for Computing Machinery, volume 13, number 10, October 1970, pages 591 through 606. 31. Woods, W A, R M Kaplan, and B Nash-Webber. "The Lunar Sciences Natural Language Information System." BBN Report 2378, Bolt, Beranek, and Newman Inc, Cambridge MA, 1972. 352 September 1981 © BYTE Publications Inc Want a Better Printer @ Lower Cost? Compare DIP with the other best seller. •# &4> *r \e^ ^ot \9^ O^ -v€tf* ,\G^ ***** ^^ ^~**%*%2* *v*<**2*»2* n-«W c*C<* W**.5.«* ^&^ moH sffl'ssssss-Ssr- t^i •«*;> »=>• See , WW ^oc^^^I vjsW ^SI*** 0W>P9 e ' wo' >we*' ,oWM' ,000 s iBfS* ***£•*» ***»<*> 180.^09/^ AS* p0S< (k\90 OP 6 ' M0 m JO** for tnO»- ,«S, coos. SB. 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BYTE September 1981 355 BYTBLINES. with the new Intel 32-bit microprocessor. I have taken the liberty of extract- ing some of the major com- ments here. The iAPX432 was designed by and for computer scien- tists, rather than electrical engineers (as were Intel's 4-, 8-, and 16-bit microproces- sors). The iAPX432's internal elements are less accessible than those in other micro- processors, so writing pro- grams will be different. "Instead of considering the machine in terms of bits and registers, you must fo- cus on software objects . . . the 432 has no assembly lan- guage, per se; you might consider its instruction set to be a high-level language . . . a nearly optimum intermedi- ate language specifically de- signed to simplify the task of writing efficient compilers. In turn, these compilers can effectively handle progams coded in high-level lan- guages." The iAPX432's in- struction set "does not con- stitute a complete operating system; rather, it contains the essential primitives from which you can construct such an operating system . . . the machine can't be pro- grammed directly in code written in, say, Ada or FOR- TRAN; you need the appro- priate compiler. Because the 432 simplifies system pro- gramming, programmers need not be hardware ex- perts; thus personnel with a lower level of expertise can program it. Further, pro- grams written in high-level languages can generally be developed more rapidly than those coded in assem- bly language. "The machine performs arithmetic operations quick- ly and with a high level of precision. It also automati- cally prevents many typical programming errors (you can't inadvertently execute data, for example). Further, it provides functional redun- dancy checking, a feature that allows graceful system degradation when a CPU [processor] fails in a multi- processing environment. And finally, the 432 ensures that all programs are natur- ally reentrant and recursive. The 432 chip set is complex and currently very expen- sive. It could incur speed penalties when performing certain operations." The iAPX432 will not be the ultimate processor. "Al- though its instruction set is close to the ideal," says EDN, "it might be improved in other ways." It will not make 4-, 8-, and 16-bit micro- processors obsolete; and, in fact, it should increase the market for these as 'peri- pheral processors. ' "In summary, a good anal- ogy is that the 432 is to stan- dard microprocessors what the 7400 Series TTL was to discrete-device logic gates and flip-flops. It should free EEs [engineers] from many mundane "system-design chores, allowing them to concentrate on more re- warding creative pursuits, while also reducing their projects' software costs. It's a minicomputer replace- ment, one that will open up scores of application oppor- tunities." Intel is already shipping a board-level iAPX432 eval- uation system, called the In- tellec 432/100. It consists of a board with a complete iAPX432 processor, RS-232C serial interface, evaluation software, and seven volumes of documentation. The user can plug the board into an Intel Intellec development system and create and ex- ecute iAPX432 programs us- ing an object-oriented lan- guage. The 432/100 costs $4250. The Intellec uses the Intel Multibus (IEEE-796), which has a 16-bit-wide data bus. The 32-bit-wide processor is interfaced to the bus via an interface-processor that han- dles data-bus transfers as two 16-bit words (the IBM 360, which was also a 32-bit processor, handled data transfers as 8-bit words, on its smaller machines). Several S-100 (IEEE-696) bus-system manufacturers have iAPX432 development projects underway. I expect to see an S-100-based iAPX432 machine with disk operating system later this year. I he Software Shop: When I was a kid, I would go to the record shop and buy a copy of one of the top-ten records on the hit-parade. Well, soon I may be going to the "software shop" to buy a copy of one of the top-ten programs. At least that is what Cut & Curl hopes. It plans to open a franchised chain of stores that sell only software — "software super- markets." Cut & Curl already franchises 500 Edie Adams Cut & Curl and Great Expec- tations Precision Haircutting salons. The first Programs Unlimited store has been opened, and Cut & Curl is talking about 100 more stores. R i andom News Bits: Apple Computer Inc re- ported that sales for the first quarter of 1981 tripled over the same period a year ago. Sales were nearly $79 million, with a net of $9.2 million — a 16% increase over the previous quarter. Also, Apple claims to have produced over 200,000 Ap- ple lis and that the Apple Ill's "production problems" have been ironed out (most of the original design group has been fired). The Apple III is now in full production. . . . Zilog reported an $11 million loss on $42 million business for 1980. Zilog has yet to show a profit. . . . Commodore expects to in- troduce its "Micromain- frame," with 132 K bytes of memory and 6502 and 6809 processors. It is really a PET computer with a second pro- cessor (the 6809). You can elect to run either the 6502 or the 6809. Commodore claims to have BASIC, FOR- TRAN, APL, Pascal, and an Assembler ready for the ma- chine. COBOL will come later. The software was de- veloped at the University of Waterloo in Ontario, Canada. Commodore has not yet set the price. ... In- terlude, Houston, Texas, claims to have sold 15,000 copies of its sex-oriented software package for the Ap- ple 1 1 and TRS-80 computers. The program asks users questions about themselves and their partners, and then tells them how to enjoy their spare time. . . . Florida Data Corporation, Melbourne, Florida, has introduced two serial dot-matrix printers that can rocket along at 600 cps (characters per second) for draft or data-processing output and at 1 50 cps for let- ter-quality output — that's three times faster than any daisy-wheel printer. The let- ter-quality output is pro- duced by passing the head over each line four times, with the dots displaced slightly on each pass to fill in the character. . . . Intel will introduce a set of two integrated circuits for the Ethernet controller and in- terface that will allow a user to implement the physical and data links. A little bit of extra circuitry, some special cables, and interfacing soft- ware, and you can connect any personal computer to an Ethernet system. . . . I exas Instruments' Bubble Bursts: In a sur- prise move, Texas Instru- 356 September 1981 © BYTE Publications Inc Circle 240 on Inquiry card. Circle 91 on inquiry card. DECLSMl Components Dependable service at discount prices Domestic and Export 1 Fprn; 1 I ■ ■ il 'V vv vv (Tlini Computer Suppliers, inc. 25 Chatham Rd., Summit, N.J. 07901 Since 1973 (201) 277-6150 Telex 13-6476 ©Mini Computer Suppliers. Inc. 1979 WOW APPLE II PLUS 64K* only $1249 16K RAM CARD INCLUDED WITH FACTORY 48K SYSTEM 16K APPLE II PLUS $1129 DISK II DRIVE & CONTROLLER ONLY $519 DISK II DRIVE ADD-ON $439 SILENTYPE PRINTER & CARD $349 Z-80 SOFTCARD $299 HAYES MICROMODEM II $299 16K RAM CARD $130 VIDEX VIDEOTERM 80 COLUMN $269 SEE PAGES 476 & 477 FOR MANY MORE PRODUCTS AT UNBEATABLE PRICES. ORDER TOLL FREE 800-854-6654 CALIFORNIA & OUTSIDE CONTINENTAL U.S. (714) 698-8088 CONSUMER COMPUTERS MAIL ORDER 8314 PARKWAY DRIVE LA MESA, CA 92041 VII^s Call A.E.I. MP's customarily need top quality and service within stringent budgetary limits. Naturally, they call A.E.I. ...For software, firmware, or hardware; For custom systems assistance, connectors, interface boards and service; For peripherals, including printers, CRT's.dlsc drives, or modems; For as little as one part such as a cable or connector, or as much as an entire national computer complex for a multi-branch company. Item: A.E.I, tests virtually every* item sold, before shipping. Item: A.E.I, initializes even' piece of software, and makes a copy. If you have a problem, A.E.I, can check to locate the problem by using the In-housc duplicate, saving you time. Item: A.E.I, has la-house expertise on every item offered. Item: A.E.I, prices arc competitive with tile lowest, no-scrvice, no in-housc expertise dealer. 40% OF ALL A.E.I. SALES ARE TO PUBLIC AND SEMI- PUBLIC INSTITUTIONS. A partial list" of A.E.I, customers whopurchascd during the last quarter of 1980 includes: University of Nebraska, University of \ irginia, U.S. Dcpt. of Interior, University of Kentucky, University of California, Massachusetts Institute of Technology, US. Air Force, Naval Air Development Center, Brown University, Univer- sity of Oregon, University of Utah, Ohio State University, Univer- sity of Southern California, 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 fust shipping, wc have time to test; expedited shipment mav prcehidc testing. "A-El. does not wish to Imply that any of these fine organizations endorse A.E.I.. merely that A.E.I. Is proud itt have them as customers. 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DISK DOCTOR is comprised of five "wards", each capable of performing a specific discette recovery operation. • Ward A: Verifies discettes and locks out bad sectors without touching the good files that remain. • Ward B: Copies whatever can be read from a "crashed" file and places it Into a good file under user control. • Ward C: Copies discettes without stopping for bad sectors. Bad sectors are replaced by spaces. • Ward D: "Un-erases" flies. That is, Ward D will recover accidentally erased disk files. • Ward E: Displays directory of recoverable erased files. DISK DOCTOR will pay for itself the first time It is used. Best of all, DISK DOCTOR operates almost complete automatically. The small amount of user Interaction is explained in the manual as well as prompted by DISK DOCTOR. Requires: 48K CP/M, two drives needed for complete operation. DISK DOCTOR: $100.00 Manual Alone: $ 10.00 CP/M Formats: 8" soft sectored, 5" Northstar, 5" Mioropolls Mod II, Vector MZ, Superbraln DD/QD, Apple II + SuperSoft First in Software Technology 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 DIGTAL RESEARCH BYTELWES ments (Tl) will phase out its magnetic bubble-memory products as part of a com- pany-wide retrenchment program. The move, ironical- ly, comes less than a month after Tl announced it was ex- panding its line. Rockwell In- ternational announced a similar move earlier this year. Besides dropping its bubble-memory line, Tl also announced plans to get out of the digital-watch business and lay off 3% of its work force. I he 64 K-BIt Memory Devices Are On The Way: Intel and a few other integrated-circuit makers are now shipping 64 K-bit memories. Prices are cur- rently in the $30 range but are expected to drop to around $8 by year's end. Look for products using these circuits by early next year. It's rumored that Apple has placed an order for 60,000 of the devices, at $12 a chip, for a new business computer. Reportedly, Intel has 256 K-bit memory devices in the prototype stage. Using the 64 K-bit devices, you could build a 64 K-byte memory system using only eight memory circuits. When the 256 K-bit products be- come available, only two cir- cuits will be required. 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 self-addressed, stamped envelope. Sol Llbes POB 1192 Mountainside NJ 07081 358 September 1981 © BYTE Publications Inc IMl/€OROi: MAKES IT ACROSS! ] =t ±=i . . FROM ONE OPERATING SYSTEM TO ANOTHER! A VITAL WAT TO PROTECT TOUR SOFTWARE INVESTMENT FOR THE FUTURE!! 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Trademarks of: 1— Byan McFarland Corp.; 2— Digital Research, Inc.; 3— Tandy Corp.; 4— Phase One Systems, Inc.; 5— Bell Telephone Laborator- ies, Inc.; 6— American Business Systems, Inc.; 7— Structured Systems Group, Inc.; 8 — Cybernetics, Inc.; 9 — Peachtree Software, Inc.; 10— Compiler Systems, Inc. TEL. 714-848-1922 8041 NEWMAN AVE., SUITE 208 HUNTINGTON BEACH, CA 92647 JL BYTE September 1981 359 Ask BYTE Conducted by Steve Ciarcia Clarcla's Circuit Court? Dear Steve, I am a member of the Evanston Township High School Computer Club, and I was wondering if you could settle a dispute for me. The supervisor of our computer room will not allow us to double-side our floppy disks because of the fact that they accelerate the accumulation of oxide and dust deposits on the read /write head of the disk drive. Is this true7 Scott Coleman Evanston II / don't like to jump into the middle of disputes, but if you can live with my opinion, I will voice it. It should not make any difference whether you have a single-sided or double-sided disk. The disk- drive head does not come in contact with the oxide sur- face: it rides above it. So, theoretically, it should not cause any accumulation on the read/write head. Now, that's in theory. In truth, there's always some oxide that comes off on the head, but if the computer room is doing regular main- tenance, which is to clean the heads every once in a while, it should never be built up to a point at which it makes any difference anyway. Perhaps the way to settle this is to have the computer club volunteer to clean the disk drives once in a while. . . . Steve Tools of the Course Dear Steve, I am beginning implemen- tation of a hands-on micro- computer experimentation and interfacing course here at the University of Dubuque Theological Seminary. I want to establish a digital-micro- processor laboratory. What would you consider to be the minimum test equipment nec- essary? Our financial re- sources are somewhat limit- ed, so your advice would be most helpful. Terry A Ward Dubuque IA At the very minimum, I would recommend that you get an oscilloscope. If you can afford it, it should be dual-trace and have at least a 15 MHz bandwidth. With it, you can troubleshoot many pieces of equipment and per- form some logic-analyzer functions. If you can afford it, of course, a logic analyzer is always a good piece of equipment to have around. However, you can spend so much time teaching people how to use a logic analyzer that you don't have any time left in the course. Other than an oscilloscope, the only other piece of equip- ment that you probably need would be a simple digital voltmeter (DVM) or digital multimeter. Often the things that are needed when teaching stu- dents are not the things that you can buy off the shelf as test equipment. Frequently, simpler equipment, such as a buffered LED (light-emitting diode) that functions as a logic probe, is what's necessary. A logic probe, 'scope, and a DVM should take care of practically anything that would arise. . . . Steve Auto Warning Dear Steve, In a book on microcom- puters that I read, the author predicted that an automotive warning device that would tell drivers they were too close to another vehicle would be devised. It occurred to me that such a gadget might be realized right now using the Polaroid development kit and a simple single-board computer. Soft- ware, it seems to me, might be the biggest hurdle. What do you think? Bob Crafts Edgartown MA The Polaroid ranging sen- sor is definitely usable for a driver-warning device like the kind you mentioned. However, I don't see this sen- sor being used as a crash- avoidance device because its response time is a little slow. 1 have seen one company using the device on each side of a car's fenders, with a dash- mounted display for the driver. In my mind, while this may work, its feasibility and production is another matter. It would seem to be rather expensive unless pro- duced in large quantities. When using the Polaroid development kit in an auto- mobile, you must try to iso- late the ignition noise from any power being drawn from the car's electrical system. From my experience, the Polaroid ranging kit is also electromagnetic interference and static sensitive. If used in a car, it should be in a shield- ed enclosure. . . . Steve Scheming Schematics Dear Steve, I would like to expand an Atari 400 or 800 with mini- mum programmable memory to a full 64 K memory by using 4116 chips. To this ex- pansion board, I would also like to add RS-232C circuitry to handle a printer and modem. Of course, it would need its own power supply. I am a technician with a good background in digital electronics but not a circuit designer. Where can 1 find the necessary schematic and parts list? Emanuel Softer Rockaway NY Expanding the memory and adding RS-232C to the Atari are two completely dif- ferent problems, each requir- ing diverse amounts of talent. The 6502 has no internal re- fresh logic, as does the Z80. External refresh logic must be added. An RS-232C serial port can be added fairly easily to the expansion connector on the side of the Atari if the proper software is added to the unit. One company that has been working on this is the Code Works, POB 550, Goleta CA 93017. I suggest that you write the Code Works (atten- tion Ron Jefferies) asking about its serial port for the Atari. It should be fairly inex- pensive because it's practical- ly all software. Presently, it is cheaper to use static memory on the Atari. Whether this situation continues will be determined by the prices of dynamic ver- sus static memory, the devel- opment of an inexpensive refresh method, or the evolu- tion of new quasistatic pro- grammable memories, such as the Zilog 7.6132. If any readers have a good circuit for using dynamic memory with a 6502, I'd appreciate seeing it. . . . Steve Little Problems Cause Big Ones Dear Steve, We have a problem with our 6800 microcomputer. 360 September 1981 © BYTE Publications Inc Circle 258 on inquiry card. HEATH OWNERS UPGRADE your H9 for a fraction of Ihe cost of a new terminal with fhese features. rLll*l\bK rKhh E69.95 kit $79.95 assembled If Columbus would have had to wait lor his H9 operaling at 600 baud, he might not have aiscoui/ered America. At last your computer can communicate with your H9 eight times (aster 14800 baudl without that annoying refresh Interrupt that causes the screen to Hash at rates greater than 600 baud. Faster listings. Faster program execution. Eight times CURSOR CONTROL $29.95 kit s 34.95 assembled Why limit your output to consecutive lines of your terminal? CURSOR CONTROL al- lows your computer to move the cursor anywhere on the screen. Add that professional touch to your displays by utilizing mashing techniques. Functions included are; left. right, up, down, left and right 20 spaces, home and erase page. U K ANA S59.95 KIT S69.95 ASSEMBLED Open a whole new world to your output. The graphical display capabilities ol GRAFIX allow you to create displays never before possible on the H9. LOWER CASE ENTRY SM . M «,«. Now you can enter lower case characters from the keyboard. A Shift Lock key allows the keyboard to operate as the standard H9 keyboard or to generate upper and lower case depending upon Ihe Shift key as per a normal typewriter. LOWER CASE DISPLAY ,«.„ »„,«, Lower case capabilities greatly improve readability on terminals modified tor 24 lines. I\tl LArJ S12.50SET 4 ARROWS $1.00 These quality contour key caps have rnolded-in alphanumerics. For that professional (eel. Full Six Month Warranty — 24 Line Compatible Northwest Computer Services, Inc. 8503 N.E. 30th Ave. Vancouver, WA 98665 (206) 573-8381 *H9 is a registered trademark of Heath Co M ASTER CARD and Vl SA Circle 316 on inquiry card HOBOTS The Future Arrives Intelligent machines are rapidly appearing in homes, automobiles, offices and factories. Affordable cameras, speech synthesizers, and even robot arms are now on the market. Such advances are giving microcomputers the power to see, hear, grasp objects, and to move around the room. Where can you learn about this technology? In Robotics Age Magazine, the journal of intelligent machines. Robotics Age reports the experience of hobbyists building their own robots, the i latest products from industry, and the most ■ powerful techniques from research labs. The B face of the world is changing. Join us as we enter the Robotics Age. H YES! I want to stay up-to-date on this fascinating '■M new technology! Company Address City State/Proyidcnce/Country Postal Code United Canada Foreign States Mexico* Rates* □ 1 year (6 issues) $15 $17 $19 □ 2 years (12 issues) $28 $32 $36 □ 3 years (18 issues) $39 $45 $51 "US Funds on US Bank D Bill VISA D MasterCard □ Bill me (N. America only) Signature Send lo: R030CIO deE PC) Box 512, Tujunga. CA 91042 RACET SORTS - RACET UTILITIES — RACET computes — RACET SORTS — RACET UTILITIES - RACET computes — RACET SORTS — RACET UTILITIES — RACET computes - -n FIELD PROVEN!! 10 MEGABYTES and MORE for the TRS-80* Model II plus SHARED ACCESS to HARD DISK DRIVE Hard/Soft Disk System (HSDS) Software allows access as single drive. You can have that 10 Megabyte continuous file - that 50,000 name maillist or inventory! Or a directory with 1000 entries! All completely compatible with TRSDOS 2.0 BASIC. You can mix floppy and hard disk drives. Includes special utilities including HPURGE, DCS Directory Catalog System, HZAP Hard Disk Superzap, and many special formatting options. Three to eight times faster than floppy! RACET quality. HARD DISK DRIVE & CONTROLLER $5995. Second User $595. HSDS Software $400. (Note: HSDS now also available for C0RVUS drives! !) INFINITE BASIC (Mod I & III Tape or Disk) Mod I $50.00, Mod III $60.00 Extends Level II BASIC with complete MATRIX functions and 50 more string functions. Includes RACET machine language sorts! Sort 1000 elements in 9 seconds! ! Select only functions you want to optimize memory usage. INFINITE BUSINESS (Requires Infinite BASIC) Complete printer pagination controls — auto headers, Packed decimal arithmetic — 127 digit accuracy +, of sorted and unsorted arrays. Hash codes. Mod I & III $30.00 footers, page numbers. -, *, /. Binary search BASIC CROSS REFERENCE UTILITY (Mod II 64K) $50.00 " SEEK and FIND functions for Variables, Line Numbers, Strings, Keywords. 'AH' : options available for line numbers and variables. Load from BASIC — Call with ' CTRL 'R. Output to screen or printer! DSM Mod I $75.00, Mod II $150.00, Mod III $90.00 Disk Sort/Merge for RANDOM files. All machine language stand-alone package for I sorting speed. Establish sort specification in simple BASIC command File. Execute ; from DOS. Only operator action to sort is to change diskettes when requested! ■ Handles multiple diskette files! Super fast sort times — improved disk 1/0 times 3 make this the fastest Disk Sort/Merge available on your TRS. ii (Mod I Min 32K 2-drive system. Mod II 64K 1 -drive. Mod III 32K 1 -drive) \ GSF (Mod I & III Tape or Disk - Specify Memory Size) I Mod I $25; Mod II $50; Mod III $30 I Generalized Subroutine Facilities. The STANDARD against which all other sorts are ? compared! And then compare prices! Machine language — fast and powerful! - Multi-key multi-variable and multi-key character string. Zero and move arrays, j Mod II includes USR PEEKS and POKES. Includes sample programs. i RACET SORTS — RACET UTILITIES — RACET computes — RACET SORTS — RACET UTILITIES — RACET computes — RACET SORTS — RACET UTILITIES — RACET computes - DISCAT (32K 1 -drive Min) Mod I, III $50.00 This comprehensive Diskette Cataloguing/Indexing utility allows the user to keep track of thousands of programs in a categorized library. Machine language program works with all TRSDOS and NEWD0S versions. Files include program names and extensions, program length, diskette numbers, front and back, and diskette free space. KFS-80 (1-drive 32K Min — Mod II 64K) Mod I, III $100.00; Mod II $175.00 The keyed file system provides keyed and sequential access to multiple files. Provides the programmer with a powerful disk handling facility for development of data base applications. Binary tree index system provides rapid access to file records. MAILLIST (1-drive 32K Min - Mod II 64K) . Mod |, III $75,00; Mod II $150.00 This ISAM-based maillist minimizes disk access' times. Four keys — no separate sorting. Supports 9 - dig i t zip code and 3-digit state code, ,%tp 30 attributes. Mask and query selection. Record access times under 4 seconds!! C0MPR0C (locill & Mod III — Disk only) Mod I $20; Mod III $30 Command Processor. Auto your disk to perform any sequence of instructions that you can give from the keyboard. DIR, FREE, pause wdiii.ni er input BASIC, No. of FILES and MEM SIZE. RUN program, respond to i inents, BREAK, return to DOSlfete, Includes lowercase driver software, debounce and screenprint! UTILITY PACKAGE (Mod H64K) $150.00 Important enhancements to the Mod II. The file recovery capabilities alone will pay for ihe package in even one -application! Fully documented in 124 page manual! XHIT, XGAT, XC0PY. and ; SUPERZAP are used to reconstruct or recover date from bad diskettes' XC0PY provides- multi-file copies, 'Wild-card- mask select, absolute sector mode and other features; SUPERZAP allows exariiine/cfiangeany sector on diskette include track-0, and absolute di-,1 . -ecovery. DCS builds consolidated tiire : ^M^^^mmf(0m & §&^^^Wv l W^\e display or listing sorted by disk name or file name plus more. Change Disk ID with DISKID. XCREATE preallocates files and sets 'L0F' to end to speed disk accesses. DEBUGII adds single step, trace, subroutine calling, program looping, dynamic disassembly and more!! DEVELOPMENT PACKAGE (Mod II 64K) $125.00 Includes RACET machine language SUPERZAP, Apparat Disassembler, and Model II interface to the Microsoft 'Editor Assembler Plus' software package including uploading services and patches for Disk I/O. fr - RACET computes -^j 1330 N. GLASSELL, SUITE M, CHECK, VISA, M/C, C.O.D., PURCHASE ORDER TELEPHONE ORDERS ACCEPTED (714) 997-4950 'TRS- 10 IS A REGISTERED TRADEMARK OF TANDY CORPORATION ORANGE, CA 92667 Circle 311 on inquiry card. Ask "VTE This problem appears to be entirely within the computer itself. Local experts and Tech- nical System Consultants (it wrote the software) all seem to be baffled by the problem. The computer is a SwTPC (Southwest Technical Prod- ucts Corporation) 6800 microcomputer wth 32 K bytes of programmable mem- ory (two 4 K-byte boards at 0000 to 1FFF hexadecimal and three 8 K boards at 2000 to 7FFF), an A2 processor board with SwTBUG monitor, MP- C interface, and MF-68 dual disk drives. The system runs under Flex 1.0. The peripher- als are: CT64 terminal, AC30 cassette interface, GE Term- inet 300 hard-copy terminal, and a PR40 parallel printer. Running MEMTESTl indi- cates one small problem at address 3C2D hexadecimal, but, other than that, there appear to be no problems. The problem appears when using the PRINT statement running under Disc BASIC 3.0 and all versions of 8 K BASIC. When running a pro- gram with any more than 25 characters in a PRINT state- ment anywhere in the pro- gram, one of the following happens: • The CT64 terminal will go into numerous control char- acter gyrations after printing the first 25 characters. • Both printers print the same "garbage" after the 25 char- acters. Each line printed will have the same "garbage" characters after the first 25 characters. Strangely enough, this problem with the terminal and the printers does not oc- cur with the LIST command on any of the aforementioned versions of BASIC. When I use the 4 K-byte version, I encounter no problems at all with the PRINT statement. Dave Coultish Ottawa, Ontario, Canada / asked our local SwTPC guru, Leo Taylor, to provide an answer. . . . Steve Unfortunately, I can't tell you anything solid, because 1 do not have the BASIC you are using. I can, however, offer a few suggestions. I suspect you have con- fused a few people with your software description. To the best of my knowledge, I guess you have Miniflex and SwTPC BASIC 3.0. Many people are confused between versions of Flex. If you have 5-inch floppy-disk drives, you can't have Flex 1.0 because it requires 8-inch drives and memory at hexa- decimal A000. TSC did not write BASIC 3.0; it was writ- ten by Rober Uterwick and adapted by SwTPC. There is never a "small memory problem. " BASIC has a way of finding memory problems that defy any other means of detection. Since you mentioned the memory error, you probably haven't swapped boards to eliminate it as a suspect. You have enough memory to remove any one board and still have the required 12 K starting at address 0000 and 4 K at hexadecimal 7000. The BASIC you are using will scan for end-of -memory . If it finds a byte it considers bad, it stops scanning, backs up one address, and loads its stack. If the end-of-memory is near the start of a page (such as 3C2D), BASIC will fail to reserve enough stack space. This can cause all sorts of problems. Thus, a minor memory problem becomes a major malfunction. . . . Leo Taylor Control Search Dear Steve, My company has been looking for a way to com- municate with a robot by using radio control. We were hoping that you might know of an integrated circuit that can be used. We need three or more digitally proportional channels that can be easily controlled by a computer. Michael Dubno Bronx NY National Semiconductor has recently introduced a set of devices for the remote- controlled toy market that may be of interest to you. The LM1871 (transmitter) and LM1872 (receiver) have the following capabilities: • two analog channels • two digital channels • operates on 27, 49, or 72 MHz band • regulated pulse-width modulation radio-frequency output It doesn't have three ana- log channels as you re- quested, but it has a lot of power for an 18-pin chip. I recommend that you contact your local National Semicon- ductor sales representative for pricing and availability. . . . Steve! In "Ask BYTE," Steve Ciarcia 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 Ciarcia POB 582 Glastonbury CT 06033 If you are a subscriber to The Source, send your questions by electronic mail or chat with Steve (TCE317) directly. Due to the high volume of inquiries, personal replies cannot be given. Be sure to include "Ask BYTE" in the address. 6809 SYSTEMS (^ 6809 SYSTEMS (^ 6809 SYSTEMS (^ 6809 SYSTEMS Gimix The Company that delivers Quality Electronic products since 1975. Featuring the GIMIX mainframe with 30 amp C.V. ferro-resonant power supply; fifteen 50 pin and eight 30 pin slot Mother Board 2 Mhz CPU with time of day clock & battery back-up, 1K RAM, 6840 programmable timer, provisions for 9511A or 9512 For ,urlner information, pricing and brochures, coniacl: Arithmetic processors, and 4 PROM/ROM/RAM sockets that can hold up to 32KB of monitor or user software. VARIETY: you can have 32KB, 56KB, 128KB and up ol static RAM. You can use 5" and/or 8" disk drives, single or double density, single or double sided, and single or double tracking with GIMIX disk controllers. You have a wide choice of serial or parallel I/O cards. EXPANDABILITY: You can add memory, l/Os, Video or Graphics cards, Arithmetic processors, additional drive capacity, and other hardware now or in the future to this SS50 bus structured system from GIMIX or other SS50 bus compatible manufacturers. 1337 WEST 37th PLACE, CHICAGO, IL 60609 SOFTWARE VERSATILITY: GIMIX systems can use TSC's FLEX or UNIFLEX and MICROWARE'S OS-9 operating systems. A wide (312) 927-5510 • TWX 910-221-4055 variety of software and languages is available for these systems. QUALITY: All boards are assembled, burned-in, and tested and feature GOLD PLATED BUS CONNECTORS. Only top quality com- ponents are used and all boards are fully buffered for maximum system expansion. All boards come complete with bus connectors and all necessary instruction and documentation. Flex and Unillex are Irademarks of Technical Systems GIMIX designs, manufactures and tests, in-house, their complete line of products. Complete systems are available to fit your Consultants inc. 0S9 is a irademark ol Microware Inc. See needs. Please contact the factory if you have any special requirements. ,ne ' r ads ,or olner GIMIX compatible sottware. and GHOST" are registered trademarks of GIMIX Inc. For GIMIX compatible software see Technical Systems Consultants ad page 199. 362 September 1981 © BYTE Publications Inc Circle 148 on inquiry card. small ad: Big Savings Sample Prices DRIVES-LOBO/TANDON/MPI-From $270.00 64K SUPERBRAIN $2640.00 QD $2990.00 ZENITH Z89/48K-1 DRIVE $2204.20 C. ITOH STARWRITER (25 cps) w/trac. $1499.00 DIABLO 630 w/trac. $2184.00 NEC5510/5530w/trac. $2650.00 EPSON MX-80 $475.00 MX-80 FT $575.00 MX- 100 $695.00 FULL LINE OF CCS BOARDS CALL Call for prices on items not listed. Prices subject to change. $100.00 min. order SUITE 439 HIS. OLIVE STREET MEDIA, PA 19063 (215) 461-5437 Disk Supply Co DISK 111 100% Compatible Model III Disks Disk III Single Drive Assy. 1 $599.00 Disk III Dual Drive Assy. $864.00 IMMEDIATE DELIVERY COMPARE & SAVE VR DATA'S Disk III features: • Completely compatible w/TRSDOS™ • State-of-the-art circuitry. • Fully tested, calibrated and burned in. • Warranty 120 days • Installation with simple hand tools • Optional dual side and/or 80tk. • Conforms to FCC Class B Specs. 'DISK III single drive assembly includes: one 40 track 5%" double density drive, power supply, .controller, mounting hardware, and applicable cables. Prices subject to change without notice. \^2@aJa 777 Henderson Boulevard Folcroft, PA 19032 To order cajl loll lree-800 345-8102 or (215) 461-5300 In PA. Olympic Sales fejjt SERVING YOU SINCE 1947 Company Main Showroom & Offices: i = e = 216 South Oxford Avenue visa- Los Angeles, CA 90004 WE HONOR &5i VISA anil MASTERCHARGE l^teRi TELEX: 67 34 77 ORDER DESKS open 7 Days a Week! 7:00 AM to 7:00 PM Mon thru Sat Sunday Noon to 5:00 PM Order Desks: (213)739-1130 TOLL-FREE TOLL-FREE (outside Calif.) (within Calif.) 800-421-8045 800-252-2153 HI HEWLETT PACKARD Retail Y HP 85 Microcomputer 3250. 00 HP-83 Microcomputer 225u\00 16K Exp-Memory Module 295 00 Graphics Plotter 7225 245o'oD Personality Mod. lor 7225 750.00 2631 B Impact prnter/hvy dty 3350.00 Option 020 lor 2631 B 150.00 8 Disk Drives to choose from 82902S 1300.00 9895A8" Dual Drive 0850.00 Graphics Tablet 911 1 A 2050.00 HP-41CV New 2.2K bytes mem 325.00 HP 41 C Calculator 250.00 Card Reader for 41 CV/C 215.00 Printer lor 41 CV/C 385.00 Optical Wand tor 41 CV/C 125.00 Quad Ram equals 4 Mem. Mods 95.00 Memory Modules for 41 C HP-97 Progrmble Printer 750.00 HP 67 Progrmble Calculator 375.00 HP 34C Progrmble Scientific 150.00 HP-38C Progrmble Bus. R/E 150.00 HP-32E Adv. Scientific 55.00 HP 37E Business Mgmt. 75.00 We carry a large inventory of Libraries, accessories and sopplies. our Cost 2595.00 1795.00 259.95 2089.95 679.95 3295.00 129.95 1149.95 5595.00 1699.95 259.95 188.95 168.95 284.95 97.95 84.95 26.95 "579.95 297.95 117.95 119.95 48.95 58.95 Write 81 request our FAMOUS Catalog! Hundreds & hundreds of products-from many manufacturers-such as SONY, CASIO, VICTOR CODEAPHONE, MATTEL, SHARP, CANON, and on and on. . .too many to list here! All goods subject to availability: this ad super- sedes alt previous ads: we are not responsible lor typographical errors: we will meet or beat any advertised prices if the competition has the goods on hand. Minimum shipping and handling S4.95. All orders subject to verification and acceptance. tcippkz computer "wearean AUTHORIZED SERVICING APPLE DEALER the best once in America '. 16K- 32K-48K-96K-128K Drive with controller DOS 3.3 ami others. 80 column cards Dow Jones & Qtiote Reporter DC Hayes Micromorietn II _^*-— . J?8» and others. . . Graphics Tablet Pascal and Fortran Languages VisiCalc and more and more APPLE III 96K and 128K "CALL US" Ask for Package One to Three Special Prices! Texas Instruments Tl 99/4 Home Computer 950.00 S379.95 ID" Color Monitor lor 99/4 650.00 319.95 32K Exp. Mem. Module 399.95 314.95 Extended Basic, a MUST for 100.00 75.00 32K Module Speech Synthesizer 150.00 129.96 Disk Memory Drive 500.00 397.95 RF Modulator G9.50 49.50 Telephone Coupler (Modem) 225.00 189.95 Printer Isuhd state! -100.00 319.95 TI-59 Progrmnle Calculator 295.00 199.95 TI-58C Progrmble Calculator 130.00 93.95 PC-100C Prntr/Plotr lor 69/58 225.00 149.95 T1-S7 Scientific Calculator 99.95 39.95 MBA Finance & Business 70.00 51.95 Tl Investmt Analyst 65.00 46.95 Tl 55 Slide Rule 40.00 32.95 Tl Proijrmr Hexidecml/Octal 65.00 48.50 We cany a latge mventuiy ot software, accessories and supplies. OHIO SCIENTIFIC Professions! Computers Retail Your Cost C8PDF-48K 3495.00 3195.00 • Dual 8" Drives «G4 col x 32 line/color • 7 MIPS FAST' •Man y more stndard feature Fortran & Pascal available Many other OS/ products available a! discounted prices, o I course! ATARI" PERS0NAL COMPUTER SPECIAL! ATARI 400 (16K)***« Retail:$595.00 Your Cosf.$339.95 Language cartridge not included; Optional basic language cartridge:S54.95 800 16K bytes ol RAM 410 Program Recorder 810 Disk Drive 825 Printer (80 col Ccnlrunic 737) 820 Printer (40 col impact) 830 Acoustic Modem 850 Interface Module Atari VisiCalc Lanje inventory uf sultwii 1080.00 90.00 lino. oo 999.95 450.00 200.00 220.00 200.00 759.95 79.95 469.95 779.95 359.95 159.95 179.95 169.95 e and accessories. PRINTERS • DIABLO (Letter Duality) 630 RI02hidirectnal/lractors 1640K109 keyboard, tractors 630 RO Receive only 1650K136 keyboard/tractors • CENTRONICSdot matrix 700 9 Parallel, heavy duty 704 9 Serial, heavy duty 737 1 Parallel 737 3 Serial 704 11 Parallel PI Electrostatic • PAPER TIGER 445G with graphics 4GGG w.thgiaphics 560G New lull size • EPSON MX 80 Impact piuliei MX 70 Impact pnnlei MX 80 FT cut sheet/tiacioi MX 100 FT 15 "paper Retail Your Cost 2965 00 2699.00 3072.00 2899.95 2710.00 2499,95 3220.00 2999.95 1460.00 1199.95 1795.00 1599.96 995.00 799.95 1046.00 899.95 1870.00 1695.00 495.00 189.95 795.00 595.00 1394 00 1195.00 1695.00 1399.00 645 00 499 95 500.00 39995 745.00 639.95 945.00 789 III) WE ALSO HAVE . • NOVATION Modems CAT Retail Your Cost 199.95 DCAT 199.95 APPLE-CAT Direct connect 349.95 • SANYO Monitors High Resolution, Number 1 seller ! 13" Color (new) high quality 550.00 12" Green Phosphorous 360.00 12" Black and White 340.00 16" Black and White 370.00 9" B/W the best seller! 236.00 159.95 159.95 314.95 399.95 239.95 219.95 239.95 149.95 AMDEK(Leedex)Higb Quality Monitors 100 12" B/W, 12 MHz 179.00 129.95 100-80 12" B/W, metal cab., 199.00 159.95 space for floppy 100-G 12" Green, 12 MHz 199.00 159.95 300-G 12" Green. 18 MHz 249.00 189.95 Color I 13" Color, NTSC comp.449.00 329.95 input, audio amp & speaker Color II 13" Color, RBG input. 999.00 699.95 hi res graphics, speaker • HAZELTINE Video Display Terminals • SHUGART Disk Drives • DEC VT100 8i VT103 Call us for your DISCOUNTED price TODAY! NEW! From Tl-Series 10 Personal Information Terminal Retail 995.00 Your Cost 13S.W Circle 263 on inquiry card. BYTE September 1981 363 Circle 167 on inquiry card. PRODUCTS COMPLETE CATALOG OF COMPUTER EQUIPMENT AT DISCOUNT PRICES. BEST PRICE EVER! $169 RAM 65. 16K STATIC S-100 RAM BY COMPUTER SYSTEM RESOURCES FEATURES: Switch selectable I/O port bank select. 4K address steps. Uses 2114L-3 low power memory. 1K de-select feature. Memory protect. Phantom, fully socketed, assembled and tested. Full one-year warranty. TELEVIDEO TERMINALS: Model 912C 695.00 Model 920C 720.00 New! Model 950 995.00 EPSON PRINTERS: Model MX-70 SCALL Model MX-80 SCALL Q.T. COMPUTER SYSTEMS: MODEL DESCRIPTION (ALL ASSEMBLED 8, TESTED) PRICE MF+DD12A . ..25 A. Mainframe: 12 Slot, S100, Dual 8" Drive .$625.00 MF+1 8A 25 A Tabletop Mainframe; 1 8 Slot, S1 00 450.00 MF+1 2A 25 A Mainframe; 1 2 Slot. S1 00, Dual 5" Drive . . 450.00 Z+80A Single Board. Z-80 Computer 2/4 Mhz, S-100 .. 18500 Z+80A/2.2 . . . .Monitor Program for Z+80A & Tarbell or VF-1 .... 30.00 RAM 32 32K Static RAM Board. Low Power, S-100 499,00 QTCIOA 2 Serial & 4 Parallel Port I/O. S-100 339.00 QTCCCSA . . . .Clock Calendar Board, S-100 125.00 QTCCCAA . . . .Clock Calendar Board, for Apple 125.00 QTCCCTRS80 Ciock Calendar Module for TRS-80 125 00 VISTA COMPUTER COMPANY: MODEL DESCRIPTION lALL ASSEMBLED & TESTED) PRICE V300/25 . . Letter Quality Printer, 25 CPS $1895.00 V300/45 ..Letter Quality Printer, 45 CPS 2195 00 V-DRIVE . . Dual 8" Disk Cabinet, Power Supply, Rack Mountable • ■ ■ 375.00 COMPUTER SYSTEM RESOURCES: MODEL DESCRIPTION (ALL ASSEMBLED & TESTED) PRICE RAM 16...16K Static RAM, S-100 $189.00 RAM 16C . Low Power (CMOS) Version of RAM 16, 1.3 Watt .... 259.00 RAM 65...16K Static RAM, I/O Port Bank Select, S-100 169.00 RAM 65C . Low Power (CMOS) Version of RAM 65. 1 A Watl . . . 279.00 RAM 32...32K Low Power 8/16 Bit Static. RAM, Fully IEEE 696 499.00 RAM 256 . .256K 8/16 Bit Dynamic RAM, Fully IEEE 696 1295.00 I/0-8 8 Port Serial I/O, Fully IEEE, up to 200K BAUD 395 00 ORDERING INFORMATION: Minimum Order is $15.00. Prices quoted do not include shipping and handling. Foreign orders require prepayment by MICR or Money Order in U.S. funds. Purchase Orders accepted from U.S. Government & firms with published A1 Rating from Dunn & Bradstreet. All other orders require prepayment, charge card, or COD shipment. TOLL-FREE PHONE NUMBER: Call Toil-Free: 1 (800) 423-5141, In Alaska, and Hawaii, call us collect at (213) 883-3244. TO RECIEVE OUR FREE CATALOG: Call our Toll-Free (800) number, or circle Reader Service tt. 7131 OWENSMOUTH AVE. / #21 D CANOGA PARK, CALIFORNIA 91303 213 / 883-3244 800/423-5141 , Books Received Apple Crunch, novel by Frederic Vincent Huber. New York: Seaview Books, 1981; 15 by 22 cm, 264 pages, hard- cover, ISBN 0-87223-687-O, $10.95. Calculator Clout: Pro- gramming Methods for Your Programmable, Maurice D Weir. Englewood Cliffs NJ: Prentice-Hall, 1981; 18.5 by 24.5 cm, 235 pages, hard- cover, ISBN 0-13-110411-X, $17.95; softcover, ISBN 0- 13-110403-9, $8.95. Computers for Everybody, Jerry Willis and Merl Miller. Beaverton OR: Dilithium Press, 1981; 14 by 22 cm, 173 pages, softcover, ISBN 0- 918398-49-5, $4.95. Computer Literacy: Prob- lem-Solving with Computers, C E Horn and J L Poirot. Austin TX: Sterling Swift Publications, 1981; 18.5 by 23.5 cm, 304 pages, soft- cover, ISBN 0-88408-133-8, $13.95. Computer Solution of Large Sparse Positive Defi- nite Systems, Alan George and Joseph W Liu. Engle- wood Cliffs NJ: Prentice- Hall, 1981; 16 by 23.5 cm, 324 pages, hardcover, ISBN 0-13-165274-5, $24.95. The Devil's DP Dictionary, Stan Kelly-Bootle. New York: McGraw-Hill, 1981; 13.5 by 20.5 cm, 141 pages, softcover, ISBN 0-07-034022-6, $7.50. Electronic Circuits Note Book, Proven Designs for Systems Applications, edited by Samuel Weber. New York: McGraw-Hill, 1981; 22 by 28 cm, 344 pages, hard- cover, ISBN 0-07-019244-8, $32.50. Manual of Pharmacologic Calculations with Computer Programs, Ronald J Tallarida and Rodney B Murray. New York: Springer-Verlag, 1981; 16 by 24.5 cm, 150 pages, hardcover, ISBN 0-387- 90500-6, $17.50. Microsoft FORTRAN, Paul M Chirlian. Beaverton OR: Dilithium Press, 1981; 14 by 22 cm, 333 pages, softcover, ISBN 0-918398-46-0, $14.95. Outland, The Movie Novel, edited by Richard J Anobile, from the screenplay by Peter Hyams. New York: Warner Books, 1981; 22 by 27.5 cm, 160 pages, softcover, ISBN 0-446-97829-9, $9.95. Program Flow Analysis: Theory and Applications, S S Muchnick and N D Jones. En- glewood Cliffs NJ: Prentice- Hall, 1981; 16 by 23.5 cm, 418 pages, hardcover, ISBN 0-13-729681-9, $23.50. Scientific Analysis for Pro- grammable Calculators with Algebraic Operating Sys- tems, H R Meek. Englewood Cliffs NJ: Prentice-Hall, 1981; 18.5 by 24.5 cm, 175 pages, hardcover, ISBN 0-13- 796417-X, $15.95; softcover, ISBN 0-13-796409-9, $7.95. Software Metrics, edited by A J Perlis, F G Sayward, and M Shaw. Cambridge MA: The MIT Press, 1981; 16 by 23.5 cm, 404 pages, hard- cover, ISBN 0-262-16083-8, $25. Thirty-Two BASIC Pro- grams for the Exidy Sorcerer, T Rugg, P Feldman, and K McCabe. Beaverton OR: Di- lithium Press, 1981; 14 by 22 cm, 265 pages, softcover, ISBN 0-918398-35-5, $16.95.1 This is a list of books received at BYTE Publica- tions during this past month. Although the list is not meant to be exhaustive, its purpose is to acquaint BYTE readers with recently published titles in computer science and related fields. We regret that we cannot review or comment on all the books we receive; in- stead, this list is meant to be a monthly acknowledgment of these books and the pub- lishers who sent them. 364 September 1981 © BYTE Publications Inc Circle 127 on inquiry card. Circle 318 on Inquiry card. LINE VOLTAGE TRANSIENT CLIPPING Features Parallel Operation PROTECTS: •Computers • Micro-Computer Systems •Word Processors •Cash Registers • Power Supplies 5000 Hits/Second PROTECTS AGAINST: • High Energy Voltage Transients •On-Off Switching •Lightning Induced Transients • Inrush of On/Off Power MARC INDUSTRIES, INC. TRANSIENT VOLTAGE SURGE SUPPRESSOR LISTED Of Of ® Dealer Inquiries invited. 7133 Rutherford Rd. Baltimore, Md. 21207 v (301)298-3130 800-638-9098 >. CATCH THE S-100 INC. BUS! S.D. Systems 80x24 Video Board A&T S.D. Systems Versafloppy II Double Density Disk Controller w/SDOS, DDBI0S, VDIAG3, & Monitor; A&T Shugart SA 800/801 R Bare Drive IMC Disk Box for 5 1 /4" Drives SSM I/0-4 Kit 2 Parallel + 2 Serial Mullen TB-4 Extender Kit w/Probe OUR LIST SPECIAL PRICE CASH PRICE 556.00 420.00 500.00 600.00 39.00 210.00 59.00 380.00 399.00 29.00 168.00 47.00 Subject to Available Quantities • Prices Quoted Include Cash Discounts. Shipping & Insurance Extra. We carry all major lines such as S.D. Systems, Cromemco, Ithaca Intersyslems, North Star, Sanyo, ECT, TEI, Godbout, Thinker Toys, SSM. For a special cash price, telephone us. Please note our new address. S-JDD,inc. 14425 North 79th Street, Suite B Scottsdale, Arizona 85260 800-582-3138 • 602-991-7870 Hours: Mon. - Fri. — 9 a.m. to 6 p.m. MST EDITOR, ASSEMBLER AND MORE! SOFTWARE DEVELOPMENT SYSTEM The Micro Works Software Development System (SDS80C) is a complete 6809 editor, assembler and monitor package contained in one Color Computer program pack! Vastly superior to RAM-based assemblers/editors, the SDS80C is non- volatile, meaning that if your application program bombs, it can't destroy your editor/assembler. Plus it leaves almost all of 16K or 32K RAM free for your program. Since all three programs, editor, assembler and monitor are co-resident, we eliminate tedious program loading when going back and forth from editing to assembly and debugging! The powerful screen-oriented Editor features finds, changes, moves, copys and much more. All keys have convenient auto repeat (typamatic), and since no line numbers are required, the full width of the screen may be used to generate well commented code. The Assembler features all of the following: complete 6809 instruction set; complete 6800 set supported for cross-assembly; conditional assembly; local labels; assembly to cassette tape or to memory; listing to screen or printer; and mnemonic error codes instead of numbers. The versatile ABUG monitor is a compact version of CBUG, tailored for debugging programs generated by the Assembler and Editor. It features examine/change of memory or registers, cassette load and save, breakpoints and more. SDS80C Price: $89.95 CRACK THOSE ROMS! SOURCE GENERATOR: This package is a disassembler which runs on the color computer and generates your own source listing of the BASIC interpreter ROM. Also included is a documentation package which gives useful ROM entry points, complete memory map, I/O hardware details and more. A 16K system is required for the use of this cassette. 80C Disassembler Price: $49.95 CBUG IS HERE! MONITOR TAPE: A cassette tape which allows you to directly access memory, I/O and registers with a formatted hex display. Great for machine language programming, debugging and learning. It can also send/receive RS232 at up to 9600 baud, including nost system download/upload. 19 commands in all. Relocatable and reentrant. CBUG Tape Price: $29.95 MONITOR ROM: The same program as above, supplied in 2716 EPR0M. This allows you to use the entire RAM space. And you don t need to re-load the monitor each time you use it. The EPR0M plugs into the Extended Basic ROM Socket or a modified ROMPACK. CBUG ROM Price: $39.95 LEARN 6809! 6809 ASSEMBLY LANGUAGE PROGRAMMING, by Lance Leventhal, contains the most comprehen- sive reference material available for programming your Color Computer. Price: $16.95 THE PARALLEL O! USE A PARALLEL PRINTER with your Color Computerl Adaptor box plugs into the serial port and allows use of Centronics/Radio Shack compatible printers with parallel interface. Assembled and tested. PI80C Price: $69.96 GOOD STUFF! 3SK RAM! MEMORY UPGRADE KITS: Consisting of 4116 200ns. integrated circuits, with instructions for installation. 4K-16K Kit Price: $39.95. 16K-32K Kit (requires soldering experience) Price: $39.95 WE SHIP FROM STOCK! Master Charge/Visa and COD Accepted P.O. BOX 1110 DEL MAR, CA 92014 714-942-2400 Circle 227 on inquiry card. BYTE September 1981 365 Circle 367 on inquiry card. THE TSEHARDSIDE 1982 MICROCOMPUTER BUYER'S GUIDE is now available! We've included such valuable information as print samples from each of the printers we carry, feature-by-feature comparisons of Micro- Computer systems in an easy-to-read table format, an informative article on Micros, and pages and pages of complete product descriptions. We're making this valuable reference available for only $2.95 (refundable on your next purchase from TSEHARDSIDE.) Charge customers are welcome to call our toll-free number: 1-800-258-1790 (in NH call 673-5144) THE TSEHARDSIDE 1982 MICROCOMPUTER BUYER'S GUIDE will soon arrive at your address via first class mail. Send to: TS€JHP)RDSID€ Dept. C, 14 South Street Milford. NH 03055 L. Yes! Send me the TSEHARDSIDE 1982 Micro-Computer Buyers Guide. I've enclosed $2.95 Please send only your FREE Price List Charge to my credit card MasterCard Visa Card No. Interbank No. Exp. Date Signature Name Address City State Zip Code B9 .J BUS-TO-BUS COMMUNICATION AA\ V\ S \V« YW^UJ. V.i iV. Vi! with the P&T-488 VSiliiiiS \\ V\1A » \\ \ Y\ V S-100 bus CP/NT Cromemco North Star ■ Inexpensive S-1 00 computers can now communicate with the IEEE-488 instrumentation bus. The P&T-488 meets the IEEE-488 1980 standard for controller, listener, and talker. ■ "Canned" software allows simple communication with the 488 bus from Basic, Pascal, and other high level languages. ■ Special features include an interactive busmonitor program and a functional self-test program. Price for (1) PST-488 with software, assembled and tested: $450 (domestic price) FOB Goleta, CA. CP/M is a registered trademark of Digital Research. PICKLES & TROUT P. O. BOX 1206, GOLETA. CA 931 16, (805) 685-4641 ^ROljf Clubs and Newsletters Join a Georgian Club The Statesboro TRS-80 Users Group is interested in all aspects of TRS-80 comput- ers, especially word-process- ing and business applications. Contact the club c/o Dr Russell A Dewey, 223 N Edgewood Dr, Statesboro GA 30458, (912) 681-3631. Apple Guild The Apple Guild promotes the interchange of informa- tion and applications among Apple users. The Guild main- tains a collection of hard- copy material and software at the Apple Resource Center. The Resource Center is located at Massasoit Com- munity College, Brockton, Massachusetts. The Guild publishes a quarterly journal and supports a telecommuni- cations system at (617) 767-1303. Contact the Apple Guild, POB 371, Weymouth MA 02188. Ohio Apples The NEO Apple Corps is devoted to Apple computers. The Corps publishes a news- letter called Apple Bits. Con- tact the group at 21750 Miller Ave, Euclid OH 44119, (216) 486-2317. Mlcropolls Users Group Members of the Micropolis Users Group use Micropolis disk drives in their computer systems. The group offers its members a monthly newslet- ter and discounts on soft- ware. Also available are li- brary disks and directories of software vendors and group 366 September 1981 © BYTE Publications Inc Circle 293 on inquiry card. Circle 342 on inquiry card. Apple Dealers. We Need You ■topple computer We've written TRA\/§, a complete surveying package that is second to none. It has all the routines needed for surveying. It's menu driven and heavily prompted. The manual was written in straightforward every day surveying language by a third generation surveyor who has been working with computers since 1965. Surveyors are generally accustomed to dedicated calculators or computers. Most of them are just doing their sur- veying and engineering computations and are not util- izing the capability of a general purpose computer like the Apple to do payroll, G/L, A/P, A/R, word processing or iob costing. That's where you come in. You sell 'em the hardware and the other software and we'll help you sell 'em our program. If you or your customer have questions, we'll be happy to answer them for you. TRAV is no stranger to surveyors. We're advertising in all national surveying publications. We have satisfied users all over the U.S. Our discounts are great. Call or write for a user manual. Surveyors Supply Co. P.O. Drawer 808 Hwy 64 at Old Apex, N.C. (919) 362-7000 Circle 195 on inquiry card. LDP88 8088 CPU BOARD • 8088 CPU 5 MHz operation upgradeable to 8 MHz • 9 vectored Inter- rupts • Fully complies with IEEE 696 electrical and timing specs • RS232 serial port with modem controls • 1K bytes of static RAM • 2 EPROM sockets (2716 or 2732) • 8087 upgrade kit available In Sept. • 8 bit bus eases Interface to other S100 bus boards • 1MByte address space • 65K I/O ports 64/256K MEMORY • 8 or 16 bit operation • Meets all IEEE 696 specs • Access time 350 ns from PSYNC low • Intel 8203 dynamic RAM controller • 24 or 16 bit ad- dress decoding • No wait states with 5 MHz 8088 or 8086 • Parity with Error Interrupt generation • No DMA RESTRICTIONS • 64K board is up- gradeable to 256 Kbyte board HAZITALL • 2 Serial RS232 ports • 2 parallel ports with handshake control • Math processor support (8231/9511 or B232/9512) • WINCHESTER DISK support • Real time programmable Interrupt • Clock/calendar with battery back up • Synchronous data communication supported LDP72 FLOPPY DISK CONTROLLER • IBM compatible single and double density format • Single or double sided drives • Programmable data record length (128 to 8192 bytes/ sector) • Multl sector and multi track transfer capability • Parallel seeks on up to 4 drives • On board digital data separator • Software selectable single or double density operation • Separate connectors for 5V«" and 8" drives • Software selection of standard or mlnldrlves allowing mixing of both drives on a single controller Software support for 86-DOS and CP/M-86. CP/M-86 $250 86-DOS $195.00 LDP88 $349.95 LDP72 $274.95 HAZITALL $325.00 LDP64K RAM $695.00 LDP128KRAM $1295.00 LDP256K RAM $2095.00 Complete systems also available. CP/M-86 Is a trademark of Digital Research 86-DOS Is a trademark of Seattle Computer Products LOMAS DATA PRODUCTS 11 Cross Street Westborough, MA 01581 Telephone: (617) 366-4335 SAVE $$ ^cippkz computer 16K APPLE II 32K APPLE II 48K APPLE II DISKW/CONTROLLER DISK ONLY APPLESOFT CARD INTEGER CARD PASCAL SYSTEM SILENTYPE PRINTER HAYES MICROMODEM Z-80 SOFTCARD VIDEX80COL BRD. 16KRAM BOARD RAM MEMORY FOR TRS-80, APPLE II 16KSET4116'S(200NS) 1089.00 1134.00 1179.00 535.00 455.00 159.00 159.00 425.00 525.00 295.00 295.00 295.00 169.00 34.95 DISCOUNT PRICES SAVE $$ ATARr 400 16K 349.00 800 16K 759.00 410 Recorder 64.00 815 Disk 1199.00 810 Disk 489.00 822 Printer 359.00 825 Printer 779.00 830 Modem 159.00 850 Interface Module 179.00 CX853 RAM 85.00 CX70 Light Pen 64.00 CX30 Paddle 18.00 CX40 Joystick 18.00 VERBATIM DISKETTES Box of 10 5 1 /4" 29.50 Box of 10 8" 39.50 North Star Computers HR2-2D-32K 2795.00 HR2-20-48K 2956.00 HR2-2D-64K 3145.00 HR2-2Q-32K 2975.00 HR2-2Q-48K 3165.00 HR2-2Q-64K 3360.00 HRAM32K 469.00 HRAM48K 662.00 HRAM64K 849.00 HDS-18 HARD DISK 4025.00 MDS-DRV-D 495.00 MDS-DRV-Q 665.00 ADC-1-D 740.00 ADC-2-D 995.00 ADC-1-Q 795.00 ADC-2-Q 1285.00 PRINTERS EPSON MX-70 EPSON MX-80 EPSON MX-80 FT GRAFTRAX INTERFACE (APPLE) CABLE 399.00 499.00 599.00 90.00 75.00 22.50 CENTRONICS 737-1 CENTRONICS 737-3 795.00 855.00 IDS445G IDS460G IDS560G 815.00 1195.00 1450.00 NEC 5510 W/TRACTORS 2650.00 NEC 5520 KSR W/TRAC. 2995.00 QUME 5/45 SPRINT FORMS TRACTOR 2675.00 195.00 STARWRITER W/TRAC. STARWRITER W/O 1695.00 TRACTOR 1500.00 General Information: We carry a large selection of hard- ware and software by other com- panies. Send for our catalog. We are an authorized repair center for APPLE, ATARI, NORTH STAR, AND EPSON. PRICES SUBJECT TO CHANGE WITHOUT NOTICE. MARYLAND RESIDENTS ADD 5% SALES TAX FREDERICK 5726 industry lane COMPUTER FREDERICK, MD. 21701 PRODUCTS, INC. Store Hours: MON. THRU THURS. 9:30 AM-9:00 PM FRI. AND SAT. 9:30 AM — 5:00 PM TO ORDER CALL: (301) 694-8884 Circle 144 on Inquiry card. BYTE September 1981 367 Circle 83 on inquiry card. ATTENTION GOVERNMENT D P USERS AND PURCHASERS We represent many fine micro products and manufacturers on the U.S. Government's GSA Schedule, including Apple, Cromemco, Micropolis and Seequa Computers Purchasing from the Schedule will save you the time consumed by the bid process. Products shipped throughout the United States and world-wide. Visit or write any of our stores for more information or to receive our catalogue of products represented. Computers, the dependable store 257 West Street, Annapolis, MD 21401 - (301) 268-6505 13A Allegheny Avenue, Towson, MD 21204 - (301) 296-0520 9330 Georgia Avenue, Silver Spring, MD 20910 - (301) 588-3748 6671 Backlick Road, Springfield, VA 22150 - (703) 644-5500 Plaza 38, 2442 Route 38, Cherry Hill, NJ 08002 - (609) 779-0023 Callers outside metropolitan areas served by our stores Please call (301) 268-5801 Career Opportunities Available * An Equal Opportunity Employer LETTER QUALITY PRINTER • DUAL USE. A PRINTER AND A TYPEWRITER • SELF TEST PROGRAM BUILT IN The BYTEWRITER is a printer consisting of a microprocessor controlled assembly internally connected to an SCM Coronamatic aooo office typewriter. $795 OTHER FEATURES - Back space. Parallel input. - Pin compatible with TRS-80 expansion interface. - Typewriter operation with nothing to disconnect. rO ORDER Send certified check or money order. Personal checks take 2 weeks. We do not ship C.O.D. Add S lO for shipping and handling in continental U.S.A. N.Y.S. residents add 7% sales tax. BYTEWRITER 125 NORTH VIEW RD., ITHACA, N.Y. (607) 272-1 132 14850 scm Coronamatic 8O00 is a trademark of SCM Corp. TRS-80 Is a trademark of Tandy Corp. BYTEWRITER is a trademark of Williams Laboratories. members. Contact the Micro- polis Users Group at 604 Springwood Cr, Huntsville AL 35803, (205) 883-2621. MCMS MCMS (Military/Civilian Microcomputer Society) is devoted to the exchange of ideas and information about all types of computers. No particular microcomputer is emphasized. Contact the Military /Civilian Microcom- puter Society, Gunter AFS, AL 36114, or call Jim Wolfe at (205) 279-4816. Lists of Used Microcomputers The Used Computer Ex- change is a listing service that puts you in direct contact with sellers. Customers pay $5 for quotes on completed transactions and for full cur- rent listings. Sellers pay a commission only if a transac- tion is completed with a buyer referred by the Ex- change. The Used Computer Ex- change lists any microcom- puter hardware that original- ly sold in the $400 to $25,000 price range. Contact the Used Computer Exchange at 2329 Hunters Woods Plz, Reston VA 22091, (800) 327-9191, ext 61; in Virginia, (703) 471-0044. 1802 Fans The VIP Hobby Computer Association is made up of users of the RCA VIP and other 1802-based microcom- puters. The group's newslet- ter, Viper, contains pro- grams, advice, and helpful hints. Membership fees are $12 per year, which includes the newsletter. Contact the VIP Hobby Computer Asso- 368 September 1981 © BYTE Publications Inc Circle 49 on inquiry card. Circle 65 on inquiry card. Circle 203 on inquiry card. J%. Components Express, Inc ^~ "Have you Hissed your computer lately?" 1380 E. Edinger. UnitCC Santa Ana. CA 92705(714) 558-3972 BROAD BAND MICROWAVE RECEIVER SYSTEM 1.8GHZ to 2.4 GHZ only $295.00 RANGE: SCOPE: With built-in-converter to channel 2, 3, or 4 of any standard TV set. Line of sight to 250 miles. Will receive within the frequency band from satelites, primary microwave stations, and repeater microwave booster stations CONTENTS. Packaged in 19"x19"x4 1/2" corrugated carton complete with: 300 Ohm to 75 Ohm Adapter 750 Ohm to 300 Ohm Adapter 60 Feet Coax Cable with Connectors 3 Feet Coax Cable with Connectors • 24" Dish • Feed-Horn Receiver • Mounting Bracket • Mounting Clamp • Instructions WARRANTY: 180 days for all factory defects and electronic failures for normal useage and handling. Defective sub assemblies will be replaced with new or re-manufactured sub assembly on a 48 hour exchange guarantee. This system is not a kit and requires no additional devices or equipment other than a TV set to place in operation. DEALER INQUIRIES INVITED. GET THE BUG OUT OF YOUR PROGRA*" Locate the bus m your prosram quickly with the all-new BUG CATCHER. Reliable and easy to use, this timesaver fits easily in pocket or case. Functional for any computer where EPROMs are used. Capable of halting the cpu at any specific address. Stop losing time and patience. BUG CATCHER is the efficient answer. $195 complete (plus applicable sales tax). els ; ii ;n \ M ARTEC SYSTEMS, INC. P.O. BOX 2069, NEWBURGH, NY 12550 (914)265-4044 PMC PERSONAL COMPUTER Ideal for small businesses, schools, colleges, homes, etc. Suitable for the experienced, inexperienced, hobbyist, teacher, etc ^^L -x. EG3000 user RAM Microsoft I Level II software compatible •Huge range of software already available • Self contained, PSU, UHF modulator, and cassette •Simply plugs into video monitor or UHF TV •Full expansion to disks and printer • Absolutely complete - lust fit into mains plug. COMPUTER POWER THAT ONCE FILLED A ROOM CAN NOW BE CARRIED IN YOUR POCKET! • Programs in BASIC • "QWERTY" Alphabetic Keyboard •1.9K Random Access Memory • Long Battery Life. TV GAME BREAK OUT KIT Has got to be one of the world's greatest TV games You really get hooked Has also 4 other pinball games and lots of options. Good kit for up grading old amusement games MINI KIT PCB. sound & vision modulator, memory chip and de code chip Very simple to construct $30.00 OR PCB $6.00 MAIN LSI $17.00 TTL SALE 74LS00 75LS04 74LS05 74LS10 74LS32 $0.15 $0.15 $0.20 $0.23 $0.35 74LS74 74LS86 74LS93 74LS157 74LS165 $0.45 $0.55 $0.90 $1.20 $1.75 74LS365 $0.75 74LS373 $2.20 Z80A $5.50 Z80 $4.20 REG. 7805 $0.90 LOOK! MICROACE/ SINCLAIR USERS SOCKETS LOW PROFILE 14 PIN $0.10 16 PIN $0.10 18 PIN $0.15 20 PIN $0.15 10V Power Adapter 600ml. $6.90 24 PIN $0.25 40 PIN $0.30 UHF Modulators $9.90 GET YOURSELF A NEW EPSON MX80 it MX70 PRINTER AND SAVE A FORTUNE Price on application Interface Cards for Apple. Pel, TRS80, and PMC - RS232 Interface Cards not necessary for parallel Full TRS80 COMP PRO MIXER . .!_ I Professional audio mixer that you can build yourself and save I over $200. Only $199 for complete kit. I power supply I $50.00 1 POSTAGE H $20 ACCESSIT AUDIO ADD-ONS pro'-!'- :,.; • • • • • • • • • • • • • • • . i §.li *\ fj.-fHfl 8K FLOATING POINT SUPER ROM PACK ONLY $35 WITH NEW MANUAL MICROACE/SINCLAIR VIDEO UPGRADE KIT Only runs with NEW ROM AOQ (Smooth screen displayl 0NLY **" MICROACE/SINCLAIR 16K RAM PLUS EXPANSION BOARD 3 SLOTS WITH EXTRA POWER SUPPLY 16K $149 4K $110 LMicrofkeJ A COMPLETE COMPUTER A new generation of miniature computers Kit ONLY $149 Post and Packing FREE Sinclair is a Registered Trademark of Sinclair Research Ltd. LMicrofkeJ £bk Please make checks and money orders payable to MicroAce or phone your order quoting Master Charge, Visa, Diners Club or American Express number for immediate despatch. Add 6% Tax for Shipments inside California. MicroAce, 1348 East Edinger, Santa Ana, California, Zip Code 92705. Telephone: (714) 547 2526 Circle 228 on inquiry card. BYTE September 1981 369 Circle 328 on inquiry card. UNBELIEVABLE! State-of-the-art Single-Board computer now available! Can be used in S-100 (Master, Slave, Multi or Single user) or Stand-Alone configurations. FINALLY, state-of-the-art performance Is avail- able at an affordable price. COMPARE THESE FEATURES: • ZSOAorZBOB • 4 TIMERS |ZCTC| • MR RAM [64KX1 CHIPS) • 2 SERIAL PORTS |ZSK>| • 4 PARALLEL PORTS |ZPIO| • UP TO I6K EPROM (2732) • NEC FLOPPY DISK CONTROLLER |UP TO FOUR 8" DOUBLE SIDED/DOUBLE DENSITY DRIVES) • INTELLIGENT WINCHESTER INTERFACE • ON-BOARD EPROM BURNER (DOES NOT REQUIRE 24VJ FOR THESE SINGLE QUANTITY PRICES: $895°° 4MZ VERSION (Z80A) 6 MZ VERSION (Z80B| 4 MZ SLAVE PROCESSOR [NO DISK CONTROLLERS ON SOARD| 6 MZ SLAVE PROCESSOR (NO DISK CONTROLLERS ONBOARD) $ 1,195°° $ 795°° ?1,095°° The S-100 version of this product can act as a Master processor. Slave processor, or Intelli- gent peripheral controller. Intra-processor com- munication Is achieved through the use of effi- cient, high speed buss transfers using special hardware/ software techniques. We also have what we think Is one of the best Implementations of a C'P/M BIOS available off the shelf. The BIOS has the following features: • All Devices INTERRUPT DRIVEN • Type Ahead Input/Output Buffers • Real-Time Clock • Time Of Day Clock • Multi-level User Password Support • Menu Driven Utilities for Format, Disk Copy, etc . • Unique Configuration Utility Program for Setting Baud Rates, Changing Step Time, Changing Passwords, etc. • Cylinder Concept used for Double Sided /Double Density Configuration Resulting In Increased Performance CP:',.■■■■■£** with 256 gray levels or 256 ra** 1 colors on standard ,- t B&W.NTSCorRGB . [ ;X "\ > coVor TV monitors. \.A*t ■ _7" Features: Compact two-board basic system 4fiOn5 1 2 Computer-generated l • Highest possible quality 480x512x8 digital video image presently available on the market • Input capability from TV camera or other sources • Variety of synchronization choices • 2 selectable video A/D conversion circuits • Choice of 1. 2, 4. 8. 16 or 32 bits per pixel • 32K-byte Image memory on the basic system • 32, 64, 128 & 256K byte system capacity • Lightpen Input • Photographic bigger control Input • Software selectable system parameters • Interfaces for TRS-80 and other processors • Comprehensive line of accessories, monitors and support software SEND FOR FREE CATALOG S DIGITAL GRAPHIC SYSTEMS = 935 Industrial Ave., Palo Alto, CA 94303 415/856-2500 Circle 310 on inquiry card. JANUS # the language that is based on the past but looks to the uses of the future: JANUS is a true compiler for a subset of ADA. ADA is the much awaited U.S. Department of Defense language. With JANUS, it is available now on your CP/M system. JANUS has such features as: Separate Compilation Records with variants Subranges, Enumerations, and Arrays Initialized Variables Integers and Arbitrary Precision Reals Produces ROMable, Re-entrant 8080 machine code and much more . . . JANUS is the face of the future. The structured language that you need for efficient programming. This is your chance to get to the head of the crowd and learn the language that will be the language of the 80's. JANUS requires an 8080/8085 or Z80 CPU, 56K of memory, and at least one 8" floppy disk. JANUS is supplied on a single density 8" floppy. For $250, you get the JANUS compiler, linker, assembler, and owners manual. FfcS CP/M is a trademark of Digital Research, Inc. ADA is a trademark of the U.S. Department of Defense OFTWARE speciafcls h stale of he art program/ring P.O. BOX 1512 MADISON, WISCONSIN 53701 THE UNBEATABLE COMBINATION : 'icippkz ^ ATARfA l/TEAM ELECTRONICS 1 (800) 547-2492 16k+ $1039 48k+ $1089 400 $329 (16k)* 800 $749 (16k) , w/o BASIC TOLL FREE NUMBER FOR ORDER DESK ONLY. IN OREGON! CALL 479-8723. REPAIRS, PARTS, AND WARRANTIES CALL (503) 479-4150. SORRY NO C.O.D.'S. MASTERCHARGE AND VISA ADD 3%. WE WILL SHIP U.P.S. FREIGHT COLLECT OR ADD 3% FOR FREIGHT AND INSURANCE TO AVOID C.O.D. CHARGES. ALLOW 10 DAYS FOR PERSONAL CHECKS TO CLEAR. PRICES SUBJECT TO CHANGE WITHOUT NOTICE. PRICES GOOD AT MAIL ORDER DEPARTMENT OF STORE #162 ONLY. DISK DRIVE W/3. 3 CONTROLLER DISK DRIVE ONLY SILENTYPE PRINTER W/INTERFACE GRAPHICS TABLET APPLESOFT OR INTEGER FIRMWARE LANGUAGE CARD (PASCAL) PARALLEL PRINTER CARD SERIAL PRINTER CARD CENTRONICS PRINTER INTERFACE CARD CCS. 7710A CCS. 7720A DATA SHIFT ADAPTOR 16K RAM CARD (MICROSOFT] Z-80CARD (MICROSOFT! HAYES M1CROMODEM A.B.T, 10 KEY PAD M&F1 SUP R TERM M&R SUP-fl MOD (MODULATOR) tGK MEMORY EXPANSION PROGRAMMA JOYSTICK ATARI 410 PROGRAM RECORDER 810 DISK DRIVE 820PHINTER 822 THERMAL PRINTER 825 80 COLUMN PRINTER 830 MODEM 850 INTERFACE MODULE 852 8K MEMORY EXPANSION 853 1GK MEMORY EXPANSION BASIC LANGUAGE CARTRIDGE VISICALC IATARII WE HAVE ATARI GAME CARTRIDGES 499 429 349 629 139 369 129 28y 279 429 499 3G9 609 530 N.E. "E" STREET GRANTS PASS, ORE 97526 HARDWARE 9" B&W MONITOR (SANYO) 159 9" B&W MONITOH (N.E.C.) 169 12" B&W MONITOR (SANYO) 199 12" GREEN MONITOR (SANYO) 259 13" COLOR MONITOR (T.I.I 349 I.D.S. 445G PRINTER 699 I.D.S. 460G PRINTER 1099 I.D.S. 560G PRINTER 1329 EPSON MX-80 PRINTER 479 EPSON CABLE AND INTERFACE 89 CENTRONICS 7371 PRINTER 743 CENTRONICS 779 2 PRINTER 889 N.E.C. SPINWRITER PRINTER 2639 QUME SPRINT PRINTER 2499 TEXAS INST. 99/4 499 APPLE SOFTWARE VISICALC VISIDEX VISIPLOT VISITERM VISITREND D.O.S. TOOL KIT D.O.S. 3.3 UPDATE APPLE WRITER SUP-R TEXT (I GENERAL BUSINESS CONTROLLER SOFT TECH PAYROLL STOCKFILE INVENTORY PROGRAM APPLE ADVENTURE 20RK SARGON CHESS GALAXIAN HI RES FOOTBALL COMPUTER QUARTERBACK MANY OTHER 8USINESS. PERSONAL, AND GAME SOFTWARE AVAILABLE NO SALES TAX ./ELECTRONIC Circle 349 on Inquiry card. BYTE September 1981 371 Event Queue September 1981 September-December Four Seminars from Manage- ment Information Corpora- tion (MIC), various sites throughout the US. These seminars are designed for businesspeople who need an introduction to system selec- tion and use. For a complete schedule of seminars, fees, and locations, contact Carol Bell, c/o MIC, 140 Barclay Ctr, Cherry Hill N] 08034, (609) 428-1020. September 8-10 An Introduction to Micro- computers for the Electronic Data-Processing Profession- al, Las Vegas NV. This course is designed for electronic data-processing managers, systems analysts, and engi- neers. Some of the course topics are applications for microcomputers in a large company, programming in BASIC, and future develop- ment of the microcomputer. A general knowledge of com- puters is recommended. For dates and other information, contact Byte Educational Ser- vices, 2412 Second Ave, Se- attle WA 98121, (206) 625-1961. September 9-11 Eurographics '81, Technical University, Darmstadt, West Germany. Almost seventy exhibitors are expected to at- tend this computer-graphics show. Detailed information can be obtained from Die- bold Deutschland GmbH, Attn: Dr H J Grobe, Feuer- bachstrasse 8, D-6000 Frank- furt/Main, West Germany. September 9-12 Workshops on Pascal and Programming Techniques, University of California Ex- tension, Santa Clara CA. An introduction to Pascal and modern programming tech- niques and style will be pro- vided in this sequence of four one-day workshops. The se- quence is structured so that each workshop is indepen- dent but leads to the next. Fees are $175 for individual courses and $600 for the four- part sequence. Contact Con- tinuing Education in Engi- neering, University of Cali- fornia Extension, 2223 Fulton St, Berkeley CA 94720, (415) 642-4151. September 10-11 Office Automation Systems, Holiday Inn, Chicago City Centre, Chicago IL. This seminar will feature discus- sions on office automation. Among the topics to be covered are Ethernet, Xerox strategies, and worker accep- tance of office automation. For information, contact Ar- chitecture Technology Cor- poration, POB 24344, Min- neapolis MN 55424, (612) 925-2930. September 10-13 The Second Annual Mid- West Computer Show, Mc- Cormick Place, Chicago IL. This show features office sys- tems, data- and word-pro- cessing equipment, telecom- munications equipment, microcomputers, computer graphics, peripherals, and other related supplies. For in- formation, contact the Na- tional Computer Shows, 824 Boylston St, Chestnut Hill MA 02167, (617) 739-2000. September 14-17 Software Info '81, Merchan- dise Mart Expocenter, Chic- ago IL. The conference theme is "Productivity Through Packaged Software." Fran Tarkenton is the keynote speaker. The president of In- put, Peter Cunningham, will deliver an address. For more information, contact Soft- ware Info, 1730 N Lynn St, Suite 400, Arlington VA 22209, (703) 521-6209. September 14-17 COMPCON Fall '81, Capital Hilton Hotel, Washington DC. The conference theme is "Productivity— An Urgent Priority." This conference is intended to provide a focus on productivity throughout the computer industry. Gen- eral inquiries for program in- formation should be ad- dressed to COMPCON Fall '81, POB 639, Silver Spring MD 20901, (301) 589-3386. September 15-16 Workstations, The Conver- gence of Information Process- ing and Telecommunications, New York NY. The role of workstations for profession- al, managerial, and executive use is the focus of this two- day seminar. Speakers will discuss the Xerox Star work- station and other new de- signs. For more information, contact Probe Research Inc, POB 251, Millburn NJ 07041, (201) 376-7730 or (212) 732-5417. September 15-17 Wescon/81, Brooks Hall, Municipal Auditorium, and Hilton Hotel, San Francisco CA. Sessions on communica- tions, components and de- vices, computer and micro- processor hardware and soft- ware, office automation, and memory systems will be pre- sented. Exhibits of computer equipment and related prod- ucts will be featured. Contact Electronic Conventions Inc, Suite 410, 999 N Sepulveda Blvd, El Segundo CA 90245, (213) 772-2965. September 16-18 Diagnostic Software: Plan- ning and Design, Colonial Hilton Inn, Wakefield MA. The Polytechnic Institute of New York is cosponsoring this seminar for design, test, and diagnostic engineers and managers. Design examples, lectures, informal sessions, and individual and group di- agnostic-programming ses- sions are part of the course. Tuition is $495. Contact Pro- fessor Donald D French, In- stitute for Advanced Profes- sional Studies, One Gateway Ctr, Newton MA 02158, (617) 964-1412. September 16-18 The Engineer As a Communi- cator, Crystal City Marriott, Arlington VA. This confer- ence is sponsored by the IEEE (Institute of Electrical and Electronics Engineers) Profes- sional Communication Socie- ty. Some of the topics to be covered are communications technology, computers in technical communications, and information gathering, storage, and retrieval. Con- tact Dr Daniel Rosich, School of Business Administration, University of Connecticut, Stamford CT 06903, (203) 322-1673. September 21-24 Microtest '81, University of Kent, Canterbury, England. This symposium will cover the testing, maintenance, and reliability of microelectronic systems from development to field use. Development sys- tems, emulators, reliable soft- ware and hardware, and high-level languages are some of the issues to be discussed. Contact the Symposium Sec- retary, Microtest '81, SERT, 57-61 Newington Causeway, London, SEl 6BL, England. 372 September 1981 © BYTE Publications Inc Circle 317 on inquiry card. Ultimate STATIC RAM is here! • Bank Select • Extended Address • 8/16 bit Data $ 295 16KB $465 32KB Assembled and Tested. Features: Model 32KUS "Uniselect: 3" • S-100 Bus - confirms with IEEE-696(S100) specifications. • Data-8 or 16 bit wide, compatible with 8 bit or new 16 bit machines. • Extended Address - 24 bit addressing. • Bank Select - by ports and bits, compatible with Cromemco, Alph Micro, North Star, and many others. • Fully Static and low power- current is 0.6A typical with 32K byte. • Two separate 16K addressing, 32K bank select with window capability in any 2K increments, any place within the addressed. • EPROM, 2716, can be mixed with RAM in any place. • Has provision to take new CMOS mem chips with battery back-up. • Will support Z80-Z8000 up to 4Mhz clock, 8086/8088 up to 8Mhz. Other S-100 Boards Available: Z80 based CPU, I/O Memory Interface, 16K Static Ram. Fully socketed, solder masks, gold contacts and guaranteed for one full year. Delivery: from stock to 72 hours. Ordering: you may call for MC, Visa or COD orders. (Add $5.00 for C.O.D.) Personal checks OK but M.O. speeds shipping. Allow 7 to 1 5 days to clear personal checks before shipping. Undamaged boards can be returned within 10 days for full refunds. Illinois residents add bVi% sales tax. OEM, Dealer pricing available S.C. Digital P.O. Box 906 Phone: Aurora, IL 60507 (312) 897-7749 Convert Your IBM Selectric into a printer for only $599 Driven by any Micro or Mini Computer ESCON i I PRODUCTS,INC. 12919 Alcosta Boulevard San Ramon, CA 94583 Call Toll Free: 800-227-2148 MARYMAC INDUSTRIES, INC. In Texas Orders Questions & Answers 1-713-392-0747 21969 Katy Freeway Katy (Houston) Texas 77450 To Order 1-800-231-3680 800-231-3681 SAVE BIG DOLLARS ON ALL TRS-80 HARDWARE & SOFTWARE TRS-80 BY RADIO SHACK. Brand new in cartons delivered. Save state sales tax. Texas residents add only 5% sales tax. Open Mon.-Sat. 9-6. We pay freight and insurance. Come by and see us. Call us for a refer- ence in or near your city. Ref: Farmers State Bank, Brookshire, Texas. WE OFFER ON REQUEST Federal Express (Overnight Delivery) Houston Intercontinental Airport Delivery (Same Day) U.P.S. BLUE (Every Day) References from people who have bought computers from us probably in your city Telex 77-4132 (FleksHou) ' TRS-80 is a Registered Trademark of Tandy Corp ED McMANUS In atock TRS-80 Model II and III No Tax on Out of Texas Shipments! 10% 15% OR MORE We Specialize In Overseas Shipments Telex 77-4132 (FleksHou) WE ALWAYS OFFER NO extra charge for Master Card or Visa We use Direct Freight Lines. No long waits. We always pay the freight and insurance Toll free order number Our capability to go to the giant TRS-80 Computer warehouse 5 hours away, in Ft. Worth, Texas, to keep you in stock. JOE McMANUS Circle 204 on inquiry card. BYTE September 1981 373 &^< ,^>" «*i7 SOFTWARE ULTIMATE SOFTWARE PLAN We'll match any advertised price on any item that we carry. And if you find a lower price on what you bought within 30 days of buying it, just show us the ad and we'll refund the difference. It's that simple. Combine our price protection with the availability of full profes- sional support and our automatic update service and you have the Ultimate Software Plan. It's a convenient, uncomplicated, logical way to get your software. Its ARTIFICIAL INTELLIGENCE Medical(PAS-3) $849/$40 Dental (PAS-3) $849/$40 ASYST DESIGN Prof Time Billing $549/$40 ^ General Subroutine. . ,$269/$40 s Application Utilities. . . . $439/$40 COMPLETE BUS. SYSTEMS Creator $269/$25 Reporter $169/$20 Both $399/$45 COMPUTER CONTROL Fabs(B-tree) $159/$20 UltraSort II $159/$25 COMPUTER PATHWAYS Pearl (level 1) $ 99/$25 Pearl (level 2) $299/$40 Pearl (level 3) $549/$50 DIGITAL RESEARCH CP/M 2.2 NorthStar $149/$25 TRS-80 Model II (P+T)$159/$35 Micropolis $169/$25 Cromemco $189/$25 PL/l-80 $459/$35 ^BT-80 $179/$30 Mac $ 85/S15 Sid $ 65/$15 2-Sid $ 90/$15 Tex $ 90/S15 DeSoool $ 50/S10 D.M.A. Ascom $149/$15 DMA-DOS $179/$35 CBS $369/$45 Formula $539/$45 GRAHAM-DORIAN General Ledger $729/$40 Acct Receivable $729/$40 Acct Payable $729/$40 Job Costing $729/$40 Payroll II $729/$40 Inventory II $729/$40 Payroll $493/$40 Inventory $493/$40 Cash Register $493/$40 Apartment Mgt $493/$40 Surveying $729/$40 Medical $729/$40 Dental $729/$40 MICRO-AP S-Basic $269/$25 Selector IV $469/$35 MICRO DATA BASE SYSTEMS HDBS $269/$35 MDBS $795/$40 ^DRSorQRSorRTL. . .$269/$ 10 MDBS PKG $1295/$60 MICROPRO WordStar $319/$60 Customization Notes... $ 89/$na Mail-Merge $109/$25 WordStar/ Mail-Merge. $419/$85 DataStar $249/$60 WordMaster $119/$40 SuperSortl $199/$40 \S (New items or new prices) CP/M users: specify disk systems and formats. Most formats available. MICROSOFT Basic-80 $289/$30 Basic Compiler $329/$30 Fortran-80 $349/$30 Cobol-80 $574/$30 M-Sort $124/$30 Macro-80 $144/$20 Edit-80 $ 84/$20 MuSimp/MuMath $224/$25 MuLisp-80 $174/$20 "PASCAL" Pascal/MT+ $429/$30 Pascal/Z $349/$30 >/ Pascal/UCSD 4.0 $429/$50 • Pascal/M $189/$20 ORGANIC SOFTWARE ^TextWriter III $111/$25 DateBookll $269/$25 ^ Milestone $269/$30 OSBORNE General Ledger $ 59/$20 Acct Rec/ Acct Pay. . . .$ 59/$20 Payroll w/Cost $ 59/$20 All 3 $129/$60 All 3 +CBASIC-2 $199/$75 PEACHTREE' General Ledger $399/$40 Acct Receivable $399/$40 Acct Payable $399/$40 Payroll $399/$40 Inventory $399/$40 Surveyor $399/$40 Property Mgt $799'/$40 CPA Client Write-up. . $799/$40 Mailing Address $349/$40 SOFTWARE WORKS Adapt (CDOS to CP/M). $ 69/$na Ratfor $ 86/$na SOHO GROUP MatchMaker $ 97/$20 Worksheet $177/$20 STRUCTURED SYSTEMS GLorARorAPorPay .$599/$40 Inventory Control $599/$40 Analyst ; $199/$25 Letteright $179/$25 QSort $ 89/$20 SUPERSOFT Diagnostic I $ 49/$20 Diagnostic II $ 84/$20 Disk Doctor $ 84/$20 s Forth (8080 or Z80). ...$149/$30 Fortran $219/$30 Fortran w/Ratfor $289/$35 Other less 10% TCS GLorARorAPorPay. $ 79/$25 All 4 $269/$99 UNICORN ^Mince $149/$25 ^Scribble $149/$25 v'Both $249/$50 Amethyst $299/$75 WHITESMITHS "C" Compiler $600/$30 Pascal (incl "C") $850/$45 "DATA BASE" FMS-80 $649/$45 dBASE II $629/$50 Condor $599/530 Condor II $899/$50 Access/80 $749/$50 "WORD PROCESSING Word Search SpellGuard VTS/80 Magic Wand Spell Binder "OTHER GOODIES The Last One SuperCalc Target BSTAM BSTMS TinyX" Tiny "C" Compiler . CBASIC-2 Nevada Cobol MicroStat Vedit MiniModel StatPak Micro B + Raid String/80 String/80 (source). . $179/$50 $229/$25 $259/$65 $289/$45 $349/$45 $549/$95 $269/$ 50 $189/$30 $149/$15 $149/$15 $ 89/$50 $229/$50 $ 98/S20 $129/$25 $224/$25 $105/515 $449/$50 $449/$40 $229/$20 $224/$35 $ 84/$20 $279/$na INFO UNLIMITED EasyWriter $224 Datadex $349 Other less 15% MICROSOFT Softcard (2-80 CP/M). $259 Fortran $179 Cobol $499 MICROPRO Wordstar $269 MailMerge $ 99 Wordstar/MailMerge . $349 SuperSortl $159 PERSONAL SOFTWARE Visicalc3.3 $159 CCA Data Mgr $ 84 Desktop/Plan II $159 Visiterm $129 Visidex $159 Visiplot $149 Visitrend/Visiplot $229 Zork $ 34 PEACHTREE* General Ledger $224/$40 Acct Receivable $224/$40 Acct Payable $224/$40 Payroll $224/$40 Inventory $224/$40 "OTHER GOODIES" dBASE II $329/$50 \S VU #3(usew/Visicalc).$ 79 Super-Text II $127 Data Factory $129 DB Master $184 OEM (complete accting) $399 Charles Mann less 1 5% 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. CO. D. ok • Prices subject to change without notice. All items subject to availability • ® — Mfgs. Trademark. THE DISCOUNT SOFTWARE GROUP 6520 Selma Ave. Suite 309 • Los Angeles, Ca. 90028 • (213) 666-7677 Int'l TELEX 499-0032 BVHL Attn: DiscSoft • USA TELEX 194-634 BVHL Attn: DiscSoft • TWX 910-321-3597 BVHL Attn: DiscSoft September 24-25 Microprocessors: Hardware, Software, and Applications, Worcester Polytechnic Insti- tute, Worcester MA. Among the courses to be offered are hardware and software ba- sics, selection and evaluation of microprocessors, memory and input/output systems, multiprocessor systems, real- time-system design, and de- bugging and circuit testing. For more information, con- tact Ginny Bazarian, c/o Continuing Education, Wor- cester Polytechnic Institute, Worcester MA 01609, (617) 753-1411, ext 517. September 24-27 The Second Annual Mid-At- lantic Computer Show, Washington Armory, Wash- ington DC. For details, see September 10-13. September 30-October 2 Data and Telecommunica- tions Expo '81, Rhein-Main- Halle, Wiesbaden, West Ger- many. This exhibition and conference will cover data communications, distributed data processing, and telecom- munications networks. Fu- ture telecommunications de- velopments, international network management, and graphics will also be dis- cussed. Contact Cahners Ex- position Group, 222 W Adams St, Chicago IL 60606, (312) 263-4866. In Europe, contact Kiver Communica- tions S A, U K Branch Of- fice, Millbank House, 171/185 Ewell Rd, Surbiton, Surrey, KT6 6AX, England. October 1981 October-November Workshops from Virginia Polytech, Virginia Polytech- nic Institute and State Uni- versity, Blacksburg VA. Workshops on microcomput- er-design interfacing and pro- gramming, digital electronics 374 September 1981 © BYTE Publications Inc Circle 120 on Inquiry card. Circle 373 on inquiry card. Circle 244 on inquiry card. THE BIGGEST NAME IN LITTLE COMPUTERS* TRS-80 Model II— Your Best Buy In a Business Microcomputer on TRS-80 computers, software and peripherals Similar values on all merchandise CALL COLLECT: 915-283-2920 Van Horn Office Supply 701 W. Broadway -- P O Box 1060 Van Horn, Texas 79855 DEALER G055 ■■■ Form F48 Provided Standard Warranty on Merchandise THE NA TIONWIDE SUPERMARKET OF SOUND** c© o o o o o o o o o o o o o o o o BUY COMPUTERS BY MAIL ORDER AND SAVE 16% APPLE HARDWARE 48K (SPECIAL) $1,125.00 Disk with Controller $ 540.00 Disk $ 440.00 Pascal $ 445.00 Graphics Tablet $ 655.00 Versawriter Digitizer System $ 215.00 ATARI 800 16K $ 775.00 PRINTERS Tl Basic Serial $1,495.00 Epson MX-80 CALL Centronics 737 Parallel $ 719.00 IDS 560 $1,395.00 CR0MEMC0 COMPUTERS ■ CALL INTERSYSTEM COMPUTERS ■ CALL TERMINALS Zenith Z 19 Soroc IQ12Q Televideo 950 Televideo 920C Televideo 9 12C ADDS Viewpoint 789.00 729.00 989.00 759.00 729.00 589.00 SOFTWARE Superbrain Double Density 64K $2,650.00 Quad Density 64K $2,977.00 NORTHSTAR Horizon-2-64 QD $3,350.00 VERBATIM & MEMOREX 5%" $ 27.50 MONITORS Leedex 12" B&W 12" GP $ 138.00 $ 152.00 Send certified check (regular checks require 2 weeks to clear) or charge to VISA or Masrer Charge Customer pays shipping. MIRO COMPUTERS, INC. 27 Long Meadow Place South Setauket, L.I., N.Y. 11720 (516) 423-7955 call mon.-sat., ioam-apm O O O o o o o o o o o o o o o o o o I THE SYSTEM INTEGRATORS • Are you tired of installing systems that cannot expand to meet your needs? • Are you tired of the problems of interfacing multi-vendor systems? • Are you tired of receiving new systems that don't work and waiting days or weeks for replacements? • Are you tired of making a computer investment and not receiving the professional help and support you deserve? If you have answered yes to any one of the above questions, you need a change! We have combined the most flexible microcomputer on the market (Ithaca Dooto%'sfei]fl[]S') with reliable, large capacity floppy and hard disk storage systems from Qume, Memorex, Shugart and Priam, along with the most dependable CRTs and printers available today. Using the industry standard CP/M* Operating System, our turnkey systems are delivered to you fully assembled, tested and burned in. PROVEN RELIABILITY — Our turnkey systems have been performing daily for over a year in high volume point-of-sale operations throughout the country. SOFTWARE AVAILABILITY — A wide variety of application software packages are ready for CP/M systems. Our library contains many of these systems, and it is expanding daily. CUSTOM DESIGN — P.O.S. Terminals, hardware and software interfaces between Ithaca Intersystems and other specialized I/O devices. COMPETITIVE PRICES — Floppy-based systems start at 57,950, 10MB hard-disk systems with floppy back-up start at $10,650. These are true turnkey system prices that include CRT. printer, and double-sided/density floppies, tested and burned in. TALK TO THE PEOPLE WHO SELL CUSTOMER SATISFACTION Specialized Business Systems 5306 S. Bannock, Littleton, CO 80120 (303) 797-8709 '"Trademark of Ithaca Intersystems, Inc. *CP/M is a Registered Trademark of Digital Research. ^ Circle 335 on inquiry card. BYTE September 1981 375 IF YOU WANT LOWER PRICES AND QUICKER SERVICE . . . YOU WANT MICROMAIL. TELE VIDEO 910 $599.00 912 $699.00 920 $749.00 950 $995.00 Model 912 C shown DIABLO 630 $1959.00 1640 RO $2269.00 1640 KSR $2499.00 1650 RO $2599.00 1650 KSR $2599.00 Model 630 shown ANADEX DP 8000 $775.00 DEC LA34DA $969.00 Shown with optional forms tractor and keypad. ANADEX DP 9500. DP 9501. DP 9000. DP 9001. $1299.00 $1299.00 $1199.00 $1199.00 TEXAS INSTRUMENTS 810/2 $1549.00 8 1 0/2 PKG (U/l vfc cp) $1679.00 TELETYPE 43 PF(TTL) $975.00 SOROC DEC 161120... IQ. 140 . . . IQ 135 . . . C. ITOH . . $689.00 VT 100 $1650.00 .$1099.00 DEC LA 34AA $ 1050.00 . . $849.00 NEC CIT 101. 5510 $2395.00 . $1625.00 5530 $2395.00 To Order: Send check to MICROMAIL, P.O. Box 3297. Santa Ana. CA 92703. Personal or company checks require two weeks lo clear. Visa/MasterCard accepted. COD. requires a 15% deposit. Handling: Add 3% to orders less than S750. 2% lo orders S751 - S2.000. 1% lo orders over S2.000 NOTE: Handling charges are waived on orders prepaid in advance by check. Shipping: We ship FREIGHT COLLECT via UPS or Motor Freight. Air and Express delivery is available -. .. .. _,„. Prices subject to change without notice. i:in.CR[Jllflfl.L., P.O. Box 3297 Santa Ana, CA 92703 Phone: 714/731-4338 TWX: 910 595 1146 for automation and instru- mentation, and sessions using the TRS-80 are part of the curriculum. All workshops are hands-on with partici- pants designing and testing concepts on the actual hard- ware. Contact Dr Lindy Leffel, Virginia Polytechnic Institute and State Universi- ty, Blacksburg VA 24061, (703) 961-5241. October 7-9 Institute on Microcomputers for Instruction and Research in Higher Education, Jane S McKimmon Center, North Carolina State University, Raleigh NC. The institute is designed to help high-level educators learn about the microcomputer and the role it can play in higher education. Contact Joyce Currie, c/o North Carolina Educational Computing Service, POB 12035, Research Triangle Park NC 27709, (919) 549-0671. October 7-21 The 1981 Far East Computer Tour, Japan, South Korea, Taiwan, and Hong Kong. This tour group will visit various computer-related conferences and exhibitions throughout the Far East. Transportation for this three- week tour, plus shows, meals, and other items are in- cluded in trip packages, ranging in price from $2290 to $3095. For more informa- tion, contact Terry Butler, Commerce Tours Interna- tional Inc, 870 Market St, Suite 742-744, San Francisco CA 94102, (415) 433-3072. October 9-11 Rhode Island Computer and Video Electronics Show, Pro- vidence Civic Center, Provi- dence RI. This is the first ma- jor computer exhibition and show to be held in Rhode Is- land. Exhibitors and sales teams will present the latest 376 September 1981 © BYTE Publications Inc Circle 234 on inquiry card. BITE TOLL-FREE SUBSCRIPTION LINE 1-800-258-5485 New Hampshire Residents Dial 924-9281 The Quickest Way To • Order a Subscription • Renew a Subscription • Change or Correct an Address • Give a Friend a Gift Subscription • Inquire about a Subscription We are waiting to help you. Call us between: 8:30-4:00 Mon.-Thurs. 8:30-1 2:30 Fridays (Eastern Time) EVTE the small systems j ournal Circle 187 on inquiry card. Z-80 and 8086 FORTH Z-80® FORTH— a complete program development system. Uses standard CP/M® compatible random access disk files for screen storage. Package includes: interpreter/compiler with virtual mem- ory management, line editor, screen editor, Z-80 Assembler, de- compiler, utilities, demonstration programs, and 80 page user manual. System requirements: Z-80 microcomputer, 48 kbytes RAM, CP/M 2.2 or MP/M® 1.1. $50.00 Z-80 FORTH WITH NAUTILUS SYSTEMS CROSS-COMPILER. Extend/modify the FORTH runtime system, recompile on a host computer for a different target computer, generate headerless code, generate ROMable code with initialized variables. Supports forward referencing to any word or label. Produces load map and list of unresolved symbols. 107 page manual. System require- ments as for Z-80 FORTH above. $200.00 8086 FORTH with line editor, screen editor, assembler, and utilities. Uses standard CP/M compatible random access files for screen storage. Requires 8086 or 8088 microcomputer, 64 kbytes RAM, and CP/M-86 operating system. $1 00.00 MACHINE TEST PROGRAM PACKAGE for Z-80 systems. Includes memory, floppy disk, printer, and terminal tests with all source code. Requires CP/M 2.2. $50.00 All software distributed on eight-inch soft sectored single density diskettes. Prices Include shipping by first class or UPS within USA or Canada. COD charges extra. Purchase orders accepted at our discretion. (CP/M and MP/M are registered trademarks of Digital Research, Inc. Z-80 is a registered trademark of Zilog, Inc.) Laboratory Microsystems 4147 Beethoven Street Los Angeles, CA 90066 (213)390-9292 A REFURBISHED DAISY WHEEL TERMINAL FOR PERSONAL COMPUTER USERS AND SMALL BUSINESSES. Now you can have letter-qualit y printin g and professional features for just $1,495? AJ daisy wheel printer terminals are renowned for exceptional performance, high reliability, and applications versatility. Now you can have all this for only $1,495* in our special limited offer. • 30 cps letter-quality printing • Changeable type faces • Full ASCII keyboard with numeric pad • High resolution X-Y plotting • Complete electronic forms control • 128-character buffer • Asynchronous RS-232 interface • Printwheel, ribbon cartridge, and cable included • 30-day parts/labor warranty US' ETTT TTTTTTTTTTTT And you can choose from a list of options including forms tractor; pin-feed platen, paper trays, side shelves, extra printwheels, APL keyboard and 2K buffer. Call your nearest AJ regional i office for details: San Jose, CA (408) 946-2900; Rosemont, IL (312)671-7155; Hackensack, NJ (201) 488-2525. Or check the phone book for the number of your local AJ sales/service office. "Price excludes options and is subject to change without notice. Model shown includes certain options. Offer available only in the contiguous U.S. ANDERSON JACOB5DN Circle 23 on Inquiry card. BYTE September 1981 377 System Log 3 so AM - 5&L&H* &j£tt&k. L D//?&A/csr/cs Vn. v £/HU<* st£ZL/dJU Name Format Attack Force, Cosmic Cassette or 5-inch floppy Fighter, Galaxy Invasion disk Type Language Arcade-style games Z80 machine code Manufacturer Computer Big Five Software Radio Shack TRS-80 Model POB 9078-185 I or III with either 16 K Van Nuys CA 91409 bytes (cassette version), or (213) 782-6861 32 K bytes and one disk (phone orders only) drive (disk version) Price Documentation Model I /Model III cassette Color leaflet plus documen- version, $15.95; Model tation in program I/Model III disk version, $19.95 Author Bill Hogue 384 September 1981 © BYTE Publications Inc Photo 1: Attack Force in progress. the game. I won't tell you what or when, so that you can be as surprised and delighted as I was. Cosmic Fighter Your ship appears at the bottom of the screen and you try to destroy a wave of alien ships that slowly drift from the top to the bottom of the screen in Cosmic Fighter. The alien missiles can move either straight or diagonally down the screen (see photo 2), and once you destroy the first wave (or let them go off the bottom of the screen), a new, more intelligent wave of aliens appears. Occasion- ally, a deadly Flagship that can fire from any angle ap- pears — you have to destroy this one quickly. If you sur- vive four waves of aliens, you have the chance to fight off the Flagship near your space station and then dock to get extra fuel for the next round. This time, however, the wave of enemy ships requires two hits per ship to destroy. This continues until you either lose three ships or run out of fuel. Galaxy Invasion Galaxy Invasion is a surprisingly faithful rendition of the popular Galaxian arcade game (which is itself a varia- tion of the original Space Invaders). In Galaxy Invasion, you have a ship at the bottom of the screen that shoots up at a formation of enemy ships (see photo 3). The enemy ships don't move toward you, but instead send out attack groups that "peel off" the main formation, gliding diagonally down the screen and strafing the area they cover with missiles. The ever-present Flagship is just as dangerous in this game as it is in the others. A partic- ularly nice feature is the different kinds of alien ships, all of which flap graphic "wings," both in the main forma- tion and during strafing runs. In fact, it's difficult to im- agine how Bill Hogue (who programs all the games) ob- tains such smooth movement of so many objects on the screen. Galaxy Invasion lacks the color and the whining sound of attacking enemy ships, but is nonetheless amazingly close to the original arcade game that costs $.25 to play. Common Features All the games use the TRS-80's arrow keys for ship movement and the space bar for missile firing. Unlike 1189 t QfTV tt756 nil KH >%* KH HI $ ;*: ft rft ift ift ift Ai rth ift ift ifc iTi iTi m m m mm v V £ vv Photo 2: Cosmic Fighter in progress. Photo 3: Galaxy Invasion in progress. September 1981 © BYTE Publications Inc 385 many microcomputer -based arcade games that exhibit a delay between a keypress and the reaction to it, these games always respond immediately to any keypress. All the games reviewed here also generate sound effects through the TRS-80 tape recorder and earphone (a stan- dard method to get sound effects in a TRS-80). Although the sound is rough and scratchy, it adds immensely to the arcade quality of the games, the most frequent sound effects occurring every time you fire a missile or an explo- sion occurs. Each of the games starts with a fancy billboard out- lined in flashing lights, which also contains the names of the ten top scorers. (My only criticism is that for a home environment, ten names seem too many; five would give you more incentive to excel.) If you make one of the top scores, you put your initials into the billboard display. From the beginning display you can either get a screen of instructions or start the game. All three games allow one or two people to play at the same time. A game may be aborted at any time. Not only are these games fun to play — they are reasonably priced. At the time of this writing, two ver- sions of each game were available (all supplied on cassette). One tape runs on both a TRS-80 Model I and a Model III with 16 K bytes of memory and costs $15.95. A disk version of each game is available for $19.95 (one game per disk); the disk will run on any Model I or Model III TRS-80 with 32 K bytes of memory and one disk drive. Big Five also sells a joystick adapter ($39.95) that allows you to connect the rugged Atari joysticks to your TRS-80. All Big Five Software programs will respond to a joystick, and although I have not seen the adapter unit, 1 am confident it is of high quality. Conclusions • To the best of my knowledge, Attack Force, Cosmic Fighter, and Galaxy Invasion are the best arcade-style games available for the TRS-80 Models I and III. In fact, they represent some of the best examples of microcom- puter game animation that I have ever seen. They are as challenging as their arcade counterparts and, as much as possible, overcome the limitations of the TRS-80 graphics. • Each game is based on an arcade-type game but adds its own distinctive touches. All games use both sound and extensive graphics. • The games are reasonably priced (especially in com- parison to graphics games that range from $20 to $40 each) and are, in my opinion, a "best buy."B The Prisoner Bob Liddil, POB 66, Peterborough NH 03458 You're on an island with your every need provided for — everything, that is, except your freedom. The island's caretaker is watching and experimenting, his ultimate goal is to take away the last scrap of individ- uality you possess. It's you against the island. You are The Prisoner. The Prisoner, by Edu-Ware Services Inc of Canoga Park, California, offers a unique, sometimes bizarre, recreation of an early 1970 s TV series that has attained cult status in recent years. To play the game, you assume the role of a disenchanted member of a covert intelligence agency. You're fed up with The Company — the whole system in general. After quitting the service, you're ab- ducted and spirited off to The Island, an isolated, self- contained community where electronic surveillance, brainwashing, plots and counterplots, illusions, delu- sions, and confusions are the order of the day. This program is not in the Adventure format that has become so popular over the last year. It is, in fact, a graphics-oriented, disk-accessing collection of fixed and randomized events that leaves you pounding your desk in endless frustration trying to make heads or tails of it. This is not necessarily bad because that is the program's intent. The game is fundamentally a contest between two equally difficult goals. The computer wishes to obtain your resignation code (and, not incidentally, doesn't care how insane it drives you). You, on the other hand, wish to escape from The Island and must use every possible means to do so. By studying the documentation carefully, you learn (well before booting the disk) that the program is going to lead you on an incredible journey. Before the game begins you are assigned a resignation code. The 386 Septembtr 1981 © BYTE Publications Inc documentation explains that this code is a condensation of your reasons for leaving The Company. When you awaken, the game begins in room #6, which contains a time-consuming invisible maze that is never the same twice. If you escape the maze, the machine greets you by asking you to identify yourself. Considering the twenty- minute invisible maze and the possible frustration of hav- ing to restart the game due to misinterpreting the screen — the tricks start coming right at the begin- ning — the inattentive player is in for rough sailing. Once in the courtyard, the movement codes are dif- ferent from those in the maze. A dead keyboard raises the frustration level before you realize that this is precisely what the author, in the guise of The Caretaker, or Master of the Island, is trying to do. Subsequent scenarios are contained in twenty "buildings," each of which you may enter at any time. The trick is to survive and outwit the event once you're inside. For example, there is the Hospital, where an en- counter with a "shrink" might be expected, and at the Town Hall you must play politics. There is a Bank, a Courthouse, a Church, and so on. All these locations are riddled with pitfalls and potential disasters. They are all designed to get you to throw in the towel and reveal your code. The program uses an awesome mixture of graphics, sound, and text. There are high-resolution pictures with beeps and whistles and low-resolution pictures that con- found you with simplicity. At times, portions of the pro- gram "jump loose" and seem to suffer a programming er- ror. However, the program is not in error — it does this by design. It's a nightmare. The program doesn't do what you think it should. The Prisoner is not for the easily frustrated, nor for those looking for a shoot-em-up arcade-type game. In- stead, The Prisoner is complex beyond belief, nearly unbeatable, and at times irrational on purpose; careening through a calculated mind-warp, its sole function is to entertain. If you follow the rules, trust your fellow man, or display anything less than a total commitment to anti- social, anti-island behavior, you will be hopelessly doomed to repeated failure. Author David Mullich, a computer science student at California State University, Northridge, is a meticulous researcher with an artist's eye for depth and detail. In speaking about The Prisoner, he said: "I was sick and tired of all the arcade games and (conventional) Adven- ture games. They seemed to be imitations of each other." As a youngster Mullich enjoyed The Prisoner on TV and found that, as a young man, the themes appealed to him. "I dreamed of doing a program on The Prisoner, and through Edu-Ware, I got the chance," he said. . Afa Clanrp Name The Prisoner Language Applesoft BASIC Type Epic nonclassical adventure game Computer Apple II or Apple II Plus Applesoft and 48 K bytes of Manufacturer memory Edu-Ware Services Inc 22222 Sherman Way Canoga Park CA 91303 (213) 346-6783 Documentation 12-page booklet Audience Price Puzzle solvers, adventure $29.95 fans and students of the Author weird David Mullich Mullich's version of The Prisoner, though not untrue to the series, is a product of his vivid imagination. It will appeal to puzzle solvers and seekers of the bizarre. ■ GET YOUR SHARE OF THE MICRO MARKET! IF A NUDGE IS ALL YOU NEED, READ ON.... HARDWARE — Boards, systems and support at the right price, featuring CCS, Televideo and others. SOFTWARE — Many industry-standard packages and some unique surprises, such as: autogen - READER — Interactively reconfigure your CP/M" BIOS. Bring new peripherals on-line quickly. Analyze your English prose. Measure how easy or hard it is to read. Do discrete-event simulation on a micro. Write parallel programs, schedule resources, much more. ■-:''.■>.•'-. .••'■ . ERESTED? GET OUR CATALOG FOR THE FULL STORY! CALL OR WRITE NOW! MICROCOMPUTER "APPLICATIONS. INC. 1124 JOLLYVILLE ROAD, AUSTIN. TX 78759' (512) 346-5264 -r.i .,- ■' -i- i Circle 230 on Inquiry card. September 1981 © BYTE Publications Inc 387 Software Review Three Microcomputer LISPs Steven P Levitan and Jeffrey G Bonar Computer and Information Science Department Graduate Research Center University of Massachusetts Amherst MA 01003 "(TELL ME MORE ABOUT YOUR FAMILY)" With these immortal words, Joseph Weizenbaum's ELIZA program confronted the world with the power of artificial intelligence (AI) techniques. A good deal of that power comes from the expressiveness of the programming language LISP. Some sophisticated and powerful LISP software packages are now available for microcomputers. In this article, we review three LISPs, one of which is distributed with a modern version of ELIZA. The LISP packages are muLISP/muSTAR from The Soft Warehouse, Cromemco LISP from Cromemco Inc, and (T.(L.C)) from The LISP Company. We have compared two basic issues: speed and functionality. In the LISPs reviewed, you will see that these two aspects are continually traded off: the slower LISP has more capabilities. The trade-off is more complex than in most languages, though. Due to the extreme flexibility of LISP, any feature of one LISP package can usually be emulated in another LISP package at the cost of increased run time. LISP purchasers should realize that LISP is anything but a standardized language. Most LISPs are fairly idiosyncratic, representing many years of development, modification, and tailoring by their designers and users. The microcomputer-based LISPs are no exception. This can cause problems for new LISP users. A LISP you purchase may look quite unlike some of the dialects discussed in textbooks. Furthermore, many features of LISP are rarely discussed in texts, but they are quite useful for LISP programming. Overview muLISP successfully provides a useful artificial -intelligence develop- ment system to the microprocessor user community. It is billed as more than a LISP interpreter for the Z80, and it is a good bit more. It provides a reasonable set of LISP functions and special forms. It also supports the user with muSTAR, a development subsystem that makes entering and debugging code as painless as possible. On the positive side, muLISP runs remarkably fast and allows for the creation and execution of fairly large LISP programs. On the negative side, some of the design decisions about error handling and type checking make debugging in muLISP harder than need be. In particular, muLISP provides almost no facilities to detect obvious nonsensical programs, and it does not allow a user to examine the data stack after an error or user inter- rupt. We like the ideas that motivated the muSTAR development sub- system, but are disappointed by some of the holes in the design. In par- ticular, it is not easy to alternate be- tween the high-efficiency environ- ment and the development environ- _At a Glance. Name muLISP/muSTAR-80 version 10/06/80 Type Version of LISP programming language Manufacturer The Soft Warehouse POB 11174 Honolulu HI 96828 Price $200, from Lifeboat Associates 1651 Third Ave New York NY 10028 (212) 860-0300; $200, from Microsoft 10800 NE Eighth, Suite 819 Bellevue WA 98004 (206) 455-8080 Format 5-inch or 8-inch floppy disk Language used 8080 or Z80 machine language Computer needed 8080-, 8085-, or Z80-based computer with at least 20 K bytes of memory, running under a CP/M-compatible operating system Documentation 100 pages, 8Vi by 11 inches (22 by 28 cm), in a 3-ring binder Audience Students, educators, computer-language enthusiasts 388 September 1981 © BYTE Publications Inc ment. Also, the screen editor is not adaptable to all terminals. The exam- ple programs delivered with the system are interesting and give just a hint of the power of a micro- computer-based LISP system. John Allen, who served as guest editor for the August 1979 BYTE LISP issue and wrote Anatomy of LISP, is the primary author of both the Cromemco and (T.(L.Q) LISP systems. Therefore these two LISPs are similar in most respects and will usually be discussed together. We believe that they are, in fact, different revisions of the same program. These LISPs are also a successful attempt to bring LISP into the world of microprocessors . In many respects, Cromemco LISP and (T.(L.C)) LISP are more modern than muLISP. They lack an in- tegrated development environment, but include many more intrinsic func- tions and data types, helpful type checking, and error detection. The extra functionality is provided at the expense of speed, but we feel that these LISPs still run acceptably fast. Our most important criticism is of the small, fixed-size stack. These LISPs do not allow one to write the power- ful recursive functions that make LISP such a clean and elegant language. This is not necessarily a practical limitation since iteration is cleanly supported,, but it is rather in- elegant and unaesthetic. Data Types in LISP Most modern programming languages support a variety of data types. So do modern LISPs. In addi- tion to the basic atoms, integers, lists, and property-list data types, different LISPs support "infinite-precision" in- tegers, floating-point numbers, character strings, arrays, and Pascal- like records. For now, we ignore the fact that functions and special forms are also data types in LISP. We discuss them separately below. (Special forms are things that look like LISP functions, but have special conventions for their evaluation. COND is an example of an intrinsic special form.) The inherent flexibility of the basic LISP data types allows almost any other data type to be emulated, but at a considerable price in execution speed and/or memory space. For ex- ample, we could emulate a character string as a list of single-letter atoms, but operations performed at the end of the "string" would be quite expen- sive. Furthermore, assuming a two- byte address, more than in bytes would be needed to store an K-character-length string. One would like a LISP implementation to directly support a variety of data types using machine-level data structures and operations. Af a danrp Name Language used Cromemco LISP, version 1.06 Z80 machine language Type Computer needed Version of LISP programming language Z80-based computer with at least 48 K bytes of memory, running under Manufacturer Cromemco's CDOS or Cromix operating Cromemco Inc systems 280 Bernardo Ave Mountain View CA 94043 Documentation (415) 964-7400 135 pages, &Vi by 11 inches (22 by 28 cm), in 3-ring binder; includes various Price CDOS manuals and a copy of Artificial $295 Intelligence Programming Format Audience 5-inch or 8-inch floppy disk Students, educators, computer-language enthusiasts NEW! ads PTOIil 3LA3iE3 • Programs 1K/2K/4K/8K eproms • Programs EEproms • Functions as an I/O device • Programs single or three supply parts • Phantom slave option • Extended device option & much more 6809 }.3jC. (Single-Board Computer) • 2K ram • RS 232 interface • 4K/8K/16KRom IEEE 696/S-100 . 20 parallel I/O lines * Simulated 8080 I/O ports: memory mapped • Baud rates: 110 to 9600 & much more ACKERMAN DIGITAL SYSTEMS, INC. (312) 530-8992 110 N. York Rd., Suite 208, Elmhurst, IL 60126 IEEE 696/S-100 All programming characteristics are software controlled; runs under CP/m* *CP/m trademark Digital Research, Inc. Circle 6 on inquiry card. September 1981 © BYTE Publications Inc 389 Circle 86 on inquiry card. xaSBS / Intertec Superbrain SPECIALS 64K Ram, List $3495 $2595 64K Quad, List $3995 $2995 NorthStar Horizon I 32KDD List $2695 , . CALL Horizon I QD Lisl $2995 CALL Horizon 2 32DD List $3095 CALL lntersystemDPS-1 List $1749 .. . CALL Z-2H Cromemco Z-2H, List $9995 . . $7945 System 2, 64K Lisl $4695 $3749 System 3, 64K, List $7995 $6395 Disk Systems Thinker Toys Discus 2D $939 Dual Discus 2D „ . . $1559 Discus 2 + 2, List $1549 $1259 M26 Hard Disk, Lisl $4995 $3949 Discus M-10, List $3695 $2995 Printers & Terminals Paper Tiger IDS-445 $649 with graphic opton $719 Centronics 730-1, Lisl $795 $549 739-1 , List $995 $769 704-9 RS232 $1495 704-11 $156S Tl 810, Lisl $1895 $1489 NEC SPINWRITER 5530 $2395 NEC SPINWRITER 5515, 5510. . $2395 Diablo 630 Lisl $2/1 1 $2399 Intertube III Lisl $895 $729 Zenith Z-19 $719 Televideo912C $679 920C $799 950 $999 Hazeltine 1420 $789 1500 $845 Soroc 120 Lisl $99b $689 IQ135 $719 140 $994 Computers Wholesale P.O. Box 144 Camillus, NY 13031 VISA- (315) 472-2582 Most items in stock for immediate delivery Factory sealed cartons, w lull factory warranty NYS residents add appropriate sales lax Prices do not include shipping. VISA and Master Charge add 3% COO orders require 25% deposit Prices subject to change without notice Support of many data types does not imply strict type checking, as in Pascal. LISP style dictates that "reasonable" data-type conversions will happen automatically. For exam- ple, if an operation performed on two integer values yields a value not representable as an integer, one would expect LISP to return a floating-point or infinite-precision in- teger as the value. Cromemco and (T.(L.C)) LISP sup- port a richer set of data types than does muLISP. They support atoms, 14-bit integers, floating-point numbers, single characters, strings up to 256 characters long, lists, and pro- perty lists. Atoms in these LISPs can take only one value. This contrasts with many LISPs, including muLISP, which allow an atom to have two values, one interpreted as a function. Each atom does have an associated property list. Cromemco and (T.(L.C)) LISP _At a Glance. Name (T.(L.C)) LISP version 1.07 Type Version of LISP programming language Manufacturer The LISP Company 18215 Bayview Dr Los Gatos CA 95030 (408) 353-2227 Price $150 Format 5-inch or 8-inch floppy disk Language used Z80 machine language Computer needed Z80-based computer with at least 48 K bytes of memory, running under a CP7M- compatible operating system Documentation 135 pages, 8Vi by 11 inches (22 by 28 cm) Audience Students, educators, computer-language enthusiasts check data types fairly strictly. For example, single characters, denoted with a back slash (" \ "), are not directly comparable to strings of length one, nor are they directly com- parable to single-character atoms. Similarly, the string "123" is not directly comparable to the integer 123. Of course, functions are provid- ed to convert between types. Cromemco and (T.(L.C)) LISP do provide facilities for building and supporting user-defined data types. Cromemco and (T.(L.C)) LISP do have functions that behave different- ly depending on the type of argument passed in. For example, the ASCII function yields an integer when passed a character and a character when passed an integer: (ASCII \ C) returns 67 (ASCII 67) returns \ C The details of how these data struc- tures are implemented are hidden from the users of (T.(L.C)) LISP. The "clever tricks" which this prevents are no loss to most programmers. The Cromemco LISP manual does discuss details of these data structures for use in writing external assembly-language functions. muLISP supports atoms (called names in the manual), infinite- precision integers (actually, they must be in the range ±256 253 ), lists, and property lists. Each name can take two values — a value that is returned when the name appears as a function call, and a value that is returned in all other situations. Each name also has an associated property list. Strings are partially supported by allowing manipulation of the print names of atoms. muLISP does almost no type check- ing. The manual discusses the im- plementation of the different data types very early, and some knowledge of this implementation is important in using the system. Many operations are defined for all data types, irrespective of whether this makes any sense. CAR and CDR, for example, will work perfectly well on numbers. This may be useful in some situations, but it often causes confus- 39 September 1981 © BYTE Publications Inc ing results and subtle bugs. We feel the marginal extra functionality and generality provided in this way are only an invitation to poor code, obscure hacking, and subtle bugs. If it is necessary to explicitly manipulate an internal representation, there should be an explicit function to do this. Of course, muLISP saves both time and space by not checking data types. User-Defined Special Forms In a LISP system, one wishes to write things which look like func- tions, but behave differently. For ex- ample, we would like to write things like the standard LISP AND: (AND predicate-1 predicate-2 . . . predicate-n ) AND evaluates each predicate-i in order, stopping if any predicate returns the value NIL (the standard LISP representation of the Boolean value false). There are two indepen- dent problems with writing AND as a standard LISP function. First, how do we pass an indefinite number of arguments, and second, how do we pass the parameters unevaluated? Special forms allow us to tell the system to treat the parameters in a special way. Below, we follow LISP convention and use the word form as a general term for both functions and special forms. muLISP solves the problem of an indefinite-length parameter list with no-spread forms, in which there is only one formal parameter. (A for- mal parameter is a dummy variable in the form definition.) When a no- spread form is called, a list of all arguments is bound to that single for- mal parameter. The form uses this list of arguments in any way desired. In muLISP, call-by-name forms are specified with NLAMBDA (for No evaluation of LAMBDA) instead of Listing 1: Definition of AND-1 in muLISP. (LAMBDA (PRED-LIST) (COND ((MULL PRED-LIST) 1 ) 7. we have reached the end of the predicates '/. and all hi*vt* evaluated non-NIL - 7. return T. <(EVAL (CAR PRED-Lim ) ) (AMD-1 (CDN PRDIMLIST) >) 7. eval the next predicatei if non-NIL "/, recur on I he rest (T NIL) 7. otherwise, the last predicate was false. 7. exit with Nil. )) Listing 2: A LISP function to print out the integers from 1 to N. The version in listing 2a is the function written in muLISP. The ver- sion in listing 2b is the function written in either Cromemco LISP or (T.(L.Q) LISP. (2a) (LAMBDA (N) (SETQ COUNT 1) (LOOP (PRINT COUNT) ( (EQ COUNT N) N) X exit test (2b) (LAMBDA (N) (DO (SETQ COUNT (PLUS CUUN'I 1)))) ( (COUNT 1 (PLUS CDUN'I I)) ) ; Only one local variable. COUNT. It is ; initialized to 1, and incremented on ; each iteration ( (EQ COUNT N) N ) i Only one exit test. It specifies an ; exit with value N when count equals 101 (PRINT COUNT) ; The body contains only the PRINT ) ) September 1981 © BYTE Publications Inc 391 LAMBDA. Normal (LAMBDA) func- tions are call-by-value and evaluate each actual parameter, binding for- mal parameters to the values of the actual parameters. (Actual param- eters are the expressions appearing as arguments to a function call.) In a call-by-name function, the formal parameters are bound directly to the actual parameters. If evaluation is desired for any of these parameters, it is explicitly specified with EVAL. We can write a muLISP version of AND defined as: (NLAMBDA PRED-LIST (AND-1 PRED-LIST)) Because AND is a call-by-name no- spread form, all its actual parameters are gathered, unevaluated, into a list that is bound to PRED-LIST. AND-1 is called with PRED-LIST as its single parameter. AND-1 is a call-by-value spread function. AND-1 is then defined as shown in listing 1. In summary, muLISP supports two types of forms — call-by-value and call-by-name — and two parameter- binding styles — spread and no- spread. All four combinations are permitted and useful. muLISP forms are compiled in a way that is largely transparent to the user. Cromemco and (T.(L.C)) LISP also allow both call-by-value and call-by- name (referred to as "call- unevaluated" in the manual) forms. Additionally, LISP macros are sup- ported. A LISP macro has only one parameter, which is bound to the complete text of the expression that calls the macro. For example, con- sider a macro TEST, which is called with the following expression: (TEST JOE (CAR A) 5) The formal parameter of TEST would be bound to the expression: (TEST JOE (CAR A) 5) The macro body is then free to manipulate the original expression with the full power of LISP. The Issue Discussed Cromemco and (T.(L.C)) LISP muLISP Cost $295-Cromemco *$150-(T.(LC)) $200 Data types supported •Atoms, integers, floating-point, characters, strings, lists, property lists Atoms, strings, infinite integers, lists, property lists Type checking *yes no Number of intrinsic functions *145-Cromemco; 144-(T.(LC)) 71 Parameter options •Optional, auxiliary, rest Spread or no-spread Special forms •Macros, read-macros "call-by-unevaluated" "Call-by-name" Control flow DO, PROG1, PROGN, COND, AND, OR, CATCH, THROW LOOP, implicit sequencing, PROG1, COND, implicit conditional, AND, OR Input and output at the terminal Allows backspace •Allows backspace, retype line, abort line Program saving and restoring Text files, absolute memory image, auto-load Text files and compressed internal image files Program-controlled input and output •Well done, I/O functions work on strings Well done Space management Dynamic space allocation for all data types, the stack is fixed in size and too small •Dynamic space allocation for all data types and the stack User environment Simple environment for developing, debugging, and executing programs; ability to examine the data stack after errors, extensive error checking; tracing abilities Separate development (muSTAR) and execution (muLISP) environments; no ability to examine the data stack after errors; too little error checking; muSTAR includes a screen editor; tracing abilities; source code for muSTAR included Linking to assembly language Cromemco-well documented and supported (T.(L.C))-not supported Possible but poorly documented Documentation/library software Clear manual suitable for beginners; many examples Clear user's manual; too terse and formal for beginners; includes several utilities and games Speed Adequate *4 to 7 times faster than the others Table 1: Comparison chart for the versions of LISP reviewed. This table summarizes the differences discussed in the text. For each issue discussed, an asterisk (*) denotes the LISP the reviewers consider to be superior. The absence of an asterisk denotes a tie among the three versions. 392 September 1981 © BYTE Publications Inc Expression evaluated in TESTER loop (T.(L.C)) counts Cromemco counts muLISP counts NIL LC DC BIGCAR BIGCDR '(HAS-AS-MEMBER-I 'B LONG1) '(HAS-AS-MEMBER-R 'B LONG1) '(REMOVE-ELEMENT-I 'B LONG41) '(REMOVE-ELEMENT-R 'B LONG41) '(HOW-RELATED 'FRODO-B 'BILBO-B) Notes: 8122 265 408 556 555 119 79 84 64 3 8061 258 409 549 552 119 79 85 66 3 31260 1667 2100 4316 4200 704 367 24 318 16 • All of the above expressions were evaluated as many times as possible in 30 seconds (60 seconds for the call to HOW-RELATED). The counts represent how many complete evaluations occurred in that time. • The counts given represent an average of three separate trials, except for the Cromemco counts, which represent one trial. The one Cromemco trial was run to verify the similarity between (T.(L.Q) and Cromemco LISP, as explained in the text. • muLISP performs particularly slowly with REMOVE-ELEMENT-I because this function uses APPEND, which is not intrinsic to muLISP. To run REMOVE-ELEMENT-I we used the recursive version of APPEND supplied in the muLISP utility library. The use of an interative APPEND would improve the performance shown. • These tests were run on a Cromemco C3 Z80-based system with 64 K bytes of memory running at 4 MHz. • The amount of available memory influences these results in two opposing ways. More memory means fewer garbage collections, but the garbage collections that do occur last longer. Table 2: Timing results for the LISP benchmark programs. For details on how this table was compiled, see the text box "Notes on LISP Benchmarks. 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September 1981 © BYTE Publications Inc 393 value computed, however, is then itself evaluated, yielding the final value of the macro call. Often a prob- lem is best solved by manipulating the text of a form's call. Macros allow this manipulation in a clean way. Macros are particularly suitable for hiding data-structure implementa- tions. Cromemco and (T.(L.C)) LISP allow a very general formal- parameter-list specification for call- by-value functions. In particular, one can specify regular parameters, op- tional parameters, auxiliary parameters, and a rest parameter. Optional parameters are bound to a specified default value if they are not specified as an actual parameter. Auxiliary parameters are local variables to the function, and they are specified with an initialization value. The rest parameter is bound to a list of all actual parameters not bound to a formal parameter of some other type. This is more flexible than the no-spread parameter of muLISP because some actual parameters can be required even though the total number is indefinite. The call-by- name and macro forms of Cromemco and (T.(L.C)) LISP also allow the definition of auxiliary parameters. We found this sophisticated parameter list to be quite useful and concise once we were familiar with it. LISP Control Structures Because LISP uses the same representation for data and pro- grams, the difference between control structures and data structures becomes blurred. For example, one function may construct a list which is then evaluated as a function call. We have done this in the function BUILD- LONG-CONS in listing 3. For the purpose of this review, we consider any construct that affects the order of expression evaluation to be a control structure. LISP easily allows the definition and integration of new con- trol structures that reflect the needs of a particular problem. In particular, the LISPs reviewed here allow one to create new control structures using the special forms described above. This means that if you like a control structure in one LISP, you can usually emulate it in another. Sequencing Control Structures The simplest control structure allows one to evaluate a sequence of expressions. In muLISP, sequential evaluation is implied by putting several expressions to be evaluated into a list. For example: ((PLUS 3 4) (CAR (QUOTE (A B))) (SETQ Z 6)) returns: (7 A 6) and binds 6 to the atom Z. Also pro- vided is the PROGl form which returns the value of the first expres- sion it evaluates, but also evaluates Text continued on page 396 Listing 3: Benchmark functions for versions of the LISP programming language. These functions are used either to build expressions used in the timing benchmarks or as functions to be benchmarked. BUILD-LONG-CONS, BUILD-DEEP-CONS, and NESTED- APPLICATION are used to build expressions that test CONS, CAR, and CDR. Listing 5 shows how they are used. REMOVE- ELEMENT and HAS-AS-MEMBER represent archetypical LISP functions. They are tested in both a recursive and an iterative form. These functions are written in a neutral "standard" LISP, except for the iterative versions of REMOVE-ELEMENT and HAS-AS- MEMBER. Comments are delimited with braces ({ }). See also table 2 and the text box labeled "Notes on LISP Benchmarks." build-long-cons ■C Builds a CONS expression which, when evaluated/ will produce a list LENGTH long of ELEMENT. Example: (BUILD-LONG-CONS 5 'A) returns (CONS 'A (CONS 'A (CONS 'A (CONS 'A (CONS 'A NIL))))) > (lambda (length element) (cond ((zerop length) ni)) ( t (list 'cons (list 'quotf element) (build -long cons (difference length 1) e lement ) > ) ) ) build— deep -cons •C Builds a CONS expression which, when evaluated/ will produce a list DEPTH deep with the innnermost list containing ELEMENT. Example: (BUILD-DEEP-CONS 5 'A) returns (CONS (CONS (CONS (CONS (CONS 'A NIL) NIL) NIL) NIL) NIL) > (lambda (depth element) (cond ((zerop depth) (litt 'quote element)) 394 September 1981 © BYTE Publications Inc Listing 3 continued: ( t (list 'cons (bui Id -deep -cons (difference depth 1) element ) nil)) ) ) nested -application < Builds an expression which, when evaluated, (lambda (function length arg) (cond ((zerop length) (lambda (element 1st) (cond ((null 1st) nil) ((eq element (car 1st)) t) (t (has-as-member element (cdr 1st))))) remove-element-r ■C Returns a copy of LST with all occurences of ELEMENT deleted. This is the recursive vevt-ion. > (lambda (element 1st) (cond ((null 1st) nil) ((eq element (car 1st)) (remove-element-r element (cdr 1st))) (t (cons (car 1st) (remove -clement element (cdr 1st)))))) has-as-member-i-muLISP •C The muLISP iterative version of HAS-AS-MEMBER. > (lambda (element 1st) (setq cdr-lst 1st) (loop ((null cdr-lst) nil > ((eq (car cdr-lf.t) element) t) (setq cdr-lst (cdr cdr-lst)))) remove-element— i-Crome/nco-tlc •C The Cromemco/(T. (L. C) > iterative version of REMOVE-ELEMENT. > (lambda (element 1st) (do ( (front nil (if (eq element (car back)) (append Front (list (car back))) front) ) (back 1st (cdr b.uk) > ) (((null back) front)))) September 1981 © BYTE Publications Ire 395 Text continued from page 394: all other expressions in order. For ex- ample: (PROG1 (PLUS 3 4) (CAR (QUOTE (AB)))(SETQ Z 6)) returns 7, but also executes the CAR, throwing away the result, and binds 6 to the atom Z. The implicit sequence evaluation, while convenient, is often confusing and error-prone. Quite often, incor- rect functions evaluate without an error because there is almost always a legal interpretation of any expression. We feel this disadvantage outweighs the convenience of the implicit form. Cromemco and (T.(L.C)) LISP pro- vide PROG1 as well as a PROGN special form. PROGN evaluates its expressions in sequence, like PROGl, but returns the value of the last ex- pression evaluated. Conditional Control Structures The standard LISP form for ex- pressing conditionality is COND. In muLISP, COND is implied in any list of expressions. If any element of the list is of the form: ( predicate expression ) and predicate evaluates to non-NIL, then control exits from the outer list with the value of expression. Like the implicit sequence evaluation, this feature trades readability and ease of debugging for conciseness and speed. Of course, an explicit COND is also available in muLISP. The COND form is augmented with an IF form in Cromemco and (T.(L.C)) LISP: (IF predicate expression-1 expression-2 . . . expression-n) If predicate is true, expression-1 is evaluated and its value is returned. Otherwise, expression-2 through expression-n are evaluated, and the Notes on LISP Benchmarks The timing benchmarks were designed to test the speed of CAR, CDR, and CONS, the workhorse functions of LISP; the speed of some simple but "archetypical" LISP functions, in both recursive and iterative form; and the speed of a reasonably large LISP program with several modules. Basically, the benchmarks were performed in an environment created by defining the functions shown in listing 3 and evaluating the expressions shown in listing 4. To test CAR, CDR, and CONS, we built long nested expressions that invoke only these functions. This is done with the functions BUILD-LONG-CONS, BUILD- DEEP-CONS, and NESTED-APPLICATION in listing 3. We chose REMOVE-ELEMENT and HAS-AS-MEMBER as the "archetypical" LISP functions. In listing 3, we show the recursive versions of each and a sample iterative version of each. Since iteration constructs differ widely among LISPs, we tailored an iterative version for each LISP to be benchmarked. Finally, listing 4 shows the genealogy program we developed as our full-size LISP program. This program allows one to enter family-tree information through the functions BORN, MARRIED, and FIRST-BORN (FIRST-BORN is used when the parents of the new entry are unknown). The family tree is queried by calling the function HOW-RELATED with two names. This program has three principal com- ponents. The first group of functions know about kinship. These functions use another set of functions that perform a breadth-first search through a family tree. Finally, the family tree is implemented with a set of graph-manipulating functions based on the language GRASPER. In listing 5, we entered parts of the BAGGINS and TOOK family trees. Our test then involved asking how Bilbo Baggins and Frodo Baggins are related. These family trees can be found in appendix C of ] R R Tolkien's Return of the King. Timing is actually done by counting the number of times a given expression will be evaluated in a fixed time period. The function TESTER in listing 5 performs the evaluation and counting repeatedly until it is interrupted after a fixed time period. The count is then examined. Note that before entering the main tester loop we always perform a garbage collection. results of evaluating expression-n are returned. All three LISPs provide the condi- tional logical operators AND and OR: (AND predicate-1 predicate-2 . . . predicate-n) (OR predicate-1 predicate-2 . . . predicate-n) If any predicate-i evaluates to NIL for AND, or other than NIL for OR, the form immediately returns with that value, evaluating no other predicate-i. Recursion and Iteration LISP is one of the cleanest languages in which to express a recur- sive solution to a problem. LISP pro- grams that use only recursion are clean, elegant, and very simple to debug because there are no global variables or side effects. Unfortunate- ly, purely recursive LISP programs are usually too slow. Typically, when an application program is found to be too slow, a few functions are taking most of the time. (In our genealogy program in listing 4, SONG-1 and SING-1 are the critically slow func- tions.) Once these functions are found, they can each be optimized, usually by making them iterative. Good LISPs must provide clean iterative structures which localize any use of side effects and easily replace recursive structures. All LISPs reviewed here have good iteration constructs. The LOOP iteration construct of muLISP allows any sequence of ex- pressions within the loop body. If any expressions are of the form: (predicate expression) then predicate is evaluated on each iteration of the loop. If it is non-NIL, the LOOP returns with the value of expression. Consider the problem of writing a function to print out the integers from 1 to n, returning the value n. In muLISP this would be written as shown in listing 2a. The DO iteration construct of Text continued on page 404 396 September 1981 © BYTE Publications Inc Listing 4: A genealogy program written in LISP. This program is intended to test the LISPs on a moderate-sized program with several modules. It allows one to enter family-tree information through the functions BORN, MARRIED, and FIRST-BORN (FIRST-BORN is used when the parents of the new entry are unknown ). The system is initialized with the function CREATE- UNIVERSE. The program has three levels: a group of functions that know about kinship, another group of functions that perform a breadth-first search, and finally a set of graph-manipulation functions that implement the family-tree data structure. how-related ■C Describes how PI is related to PP.. First we check the simple cases that PI is the same as P2 ,-nd that PI is P2 ' s spouse. Otherwize. we call DESCRIBE-RELA1 ION after computing the path in the family tree between PI PP. > (lambda (pi p2) (cond ((eq pi p2) (lii.t 'mine)) ((eq pi (spouse of |>P)> (list ( sex-of-spouse pi))) (t ( descr ibe-re ) ati on pi P2 (f ind-path-between pi p2))))> describe-r elation -C Based on a legal connecting path through the family tree/ describes how PI is related to PP. PATH-UP-AND-DOWN is a list with the distance up from PI to the lowest common ancestor and the distance down to Pfi Prom the lowest common ancestor. We use a LAMBDA binding to cut this list into components Dl and D2. If either Dl or D2 is zero* the relationship is direct. Other cases are dealt with by NOT-DIRECT-RELATIONS. > (lambda (pi p2 path-up-and-dotmi) (cond ((null path-up-«nnd down ) '(not related by blood) ) (t ((lambda (dl dp) (cond ((eq dl 0) (direct-ancestor pi d2) ) ((eq d2 0> (d irect-descendent pi dl)) (t (not-d irect— relations Pi p2 dl d2)> ) ) (car path-up -and down) (cadr path-up <:n (lambda (younger distance) (add-grand-greats ( sex -of -ch i Id younger) distance)) d irect-ancestor ■C The relationship is known to be parent, grandparent/ great grandparent/ or etc. This function invokes choosing the right relation name by sex - father or mother, and the right number of greats. > (lambda (older distance) (add-grand-greats (se x -of-parent older) distance)) Listing 4 continued on page 398 September 1981 © BYTE Publications Inc 397 Listing 4 continued: not-direct-relations < Based on the distances Dl and D2, determine the relation PI and P2. If Dl and D2 are both one, then PI and P2 are siblings. If Dl equals D2i and both ore greater than one, then PI is P2's nth cousin/ where n is Dl (or D2) minus one. Finally* if Dl is not equal to Dei. and both are greater than onei PI is P2's Nth cousin. M removed. N is Dl minus li and M is the absolute value of the difference between Dl and D2. > (lambda (pi p2 dl d2) (cond ((and (eq dl 1) (rq d2 1>) (list (sex-of-sib ling pi))) ((eq dl d2) (lit-t (difference dl 1) 'to us in) ) ((eq dl 1) (ancestors-sibling pi d2)) ((eq d2 1) ( sib 1 inq& descendent pi dl)) (t (list (difference dl 1) 'cousin (abs (di FPcvence d2 dl) > 'removed ) ) ) ) find -path -bet we en ■C To find a path between PI and P2 we use a breadth first search. Starting at PI we look for P2 onr step away, then two steps away, etc. The BPEADTH-FIf (lambda (pi p2) (breadth-first-search Oif.t (list pi p',<) > ' the-great-unknown ) ) breadth-first-search ■C We take the first unexpanded node of the unexpanded list, if it represents the goal node, vie return its accumulated distances. Otherwize, we check its relations to see who needs to be added as nodes to the unexpanded list. > (lambda (unexpanded goal-node) (cond ((null unexpanded) nil) ( t ( ( lambda (next) (cond ((rq (node-of next) goal-node ) O ist (dist-up-of next) ( d ist-down-of next))) (t (check-relatives next goal-node (cdr unexpanded))))) (car unexpanded))))) chec k -relatives 398 September 1981 © BYTE Publications Inc Listing 4 continued: < Appends new nodes on the end of the unexpended list. By putting them on the end we get a breadth first search. These new nodes are built by BUILD M-W-UNEXPANDED which uses various information from thr lort node expanded > (lambda (last-expanded person unexpanded ) (breadth-first-search (append unexpanded ( bu i Id-new— unexpanded (node-of last-e x panded ) ( d ist-up-of last-expanded ) ( d ist-down-of last-expanded ) (where— of last-expanded ) ) ) pt-iT.on ) ) bui ld-new-une xpanded ■C Finds all the neighbors of the rmde last expanded and builds unexpanded nodes for them. ) f we have not yet started down in the tree (D-.OUWN equals O), we can also build unexpanded nodes from parents of the node last expanded. In each case we will note the new distances and the node I«i»t expanded. > (lambda (node d— up d-down from) (append (make-unexpanded (i-ong node 'child) node d up (plus d-down 1 ) h-om) (cond ((eq d-down 0) (make-unexpanded ( song node 'parent ) node (plus d-up 1 ) d-down from) ) (t nil) ) ) ) make— unexpanded ■C Given a list of nodes and information about how we got to those nodes/ builds unexpanded nodes for the breadth first search. We do not make an unexpanded node for THE-GREAT-UNKNOWN or for the p]«-(f we were at two steps ago. In this way we avoid infinitely looping through the family tree. > (lambda (node-list from d— up d-down from— from) (cond ((null node-list) nil) ((or ( e q (car n o d c - 1 i s t ) 'the— great -unknown) (eq (car node-list) from-from)) (make-unexpanded (ctir node-list) Prom <• up (lambda ( unexpand ed-entry ) (c*;r urn- xpanded-entr y ) ) d ist-up-of (lambda ( unexpanded-entry ) (c;cJr unexpanded-entry ) ) d ist-down— of (lambda (unexpanded-entry) (c«*ddr unexpanded-entry)) inhere— of (lambda (unexpanded-entry) (cfidddr unexpanded-entry)) born < Allows a user to declare that PERSON of sex SEX was born to PARENT1 and PARENT2. Various cn*:ph primitives are used to link the new arrival into the family tree. These primitives are explained below. > (lambda (person parentl parents <.fx> (progn (cun person) ( bun person sex ) (cip person 'chiJd parentl) (cip person 'child parent2) (cop person 'p^re-nt parentl) (cop person 'poretit parent2) person ) ) marr ied ■C Allows a user to declare that PERSON! and PERS0N2 were married. The graph processing primitives used to do this are explained below. > (lambda (personl person2) (progn (cap personl 'spouse person2) (list personl perr-onS))) add-grand -greats ■C Adds the right NUMBER of "grand"? and "greaf's to the basic relationship name ONE-CASE. > (lambda (one— case number) (cond ((eq_ number 1) (list one— case)) ((eq number 2) (list 'grand one-case)) (t (cons 'great (add— grand qreats one-case (d if f erence number 1) ) ) ) ) ) add-greats ■C Add the right NUMBER of "greaf's to the basic relationship name ONE-CASE. Note that "grand "s on- not used. This is more common usage for great uncles and aunts. > (lambda (one-case number) (cond ((eq number 1) (list one-case)) (t (cons 'great 4CX3 September 1981 © BYTE Publications Inc Listing 4 continued: (add-gveMs one-case (difference number 1)))))) ancestors-sib 1 ing < Builds up the appropriate kind of uncle or aunt based on the sex of UNCLE-OR-AUNT and the DISTANCE. > (lambda (unc le-or-aunt distance) (add-greats (se x-of-unc. lc-or-aunt uncle-or-aunt ) (difference- dif.tance 1))) siblings-descendent ■C Builds up the appropriate kind of niece or nephew based on the sex of NIECE-OR-NEPHEW and the DISTANCE. > (lambda (niece-or— nephew distance-) (add-greats (se x-of-niecc -or-nephew niece-or— nephew) (difference distance 1))) spouse-of < Follows NODEs spouse link using *i greph processing primitive. > (lambda (node) (car (song node 'spout.e))) sex-of-chi Id ■C This and the next 6 functions chose the appropriate relation name based on the PERSONS name. They all pass a FEMALE-CHOICE and a MALE-CHOICE to CHOOSE-BY-SEX. which actully looks up the sex of PERSON and returns a choice. > (lambda (person) ( choose— by— sex person 'daughter 'son)) sex-of-parent (lambda (person) ( choose— by-sex person 'mother 'father)) sex-of-spouse ( lamb da (person ) (choose-by-sex person 'wife 'husband)) se x-of-unc le-or-aunt ( lambda ( person ) ( choose— b y-sex person 'nunt 'uncle)) sex-of— niece-or— nephew ( lambda ( person ) (choose-by-sex person 'niece 'nephew)) sex-of-sib 1 ing ( lambda (person ) ( choose-bg-sex person 'firter 'brother-)) choose-by-sex (lambda (person female-choice mi;) e; -choice ) (cond ((eq (sex— of person) 'female) female-choice ) ( t male-choice ) ) ) sex-of < Uses graph processing primitives to look up the sex of PERSON > (lambda (person) (vun person)) Listing 4 continued on page 402 September 1981 © BYTE Publications lnc 401 Listing 4 continued: ■C Useful to enter a person whose parents are not known. > (lambda (person sex) (progn ( c un person) ( b un person sex))) create-uni verse < Sets up the two global lists used by the graph processing system. The UNIVERSE-NO.DE-LIST i «. a )ist of all the nodes in the system. Here, a node is a person in the family tree. The UNIVERSE-EJDGE-LIST holds all the connections between nodes in the system. These are kept at triples of (nodel edge node2) to represent an edge called EDGE pointing from JMDDE1 to N0DE2. In this casr the edges will be familial relations. This function al«>o creates THE- GREAT-UNKNOWN who is related to no one. > (lambda nil (progn (setq un iverse node -1 ist nil) (setq universe -edge-list nil) (cun 'the-great -unknown ) ) ) cun •C Creates a node in the universe bi| updating the UNIVERSE-NODE-LIST. > < lamb da (node ) (progn (setq universe -node -list (cons node universe-n ode- list) ) node ) ) bun ■C Binds a value to a node in the universe. Node values are kept on the node's property list/ under the indicator VALUE. Here the value of a node is the per&ons sex. > (lambda (node value) (putprop node value 'value)) vun < Get the value of a node in the universe. The converse of bun > (lambda (node) (getprop node 've- )ue>) sun < Set of all nodes in the universe. This is just the UNIVERSE-NODE-LIST itself. > (lambda nil universe-node-1 ist ) cip •C Create an inpointing edge. This just reverses the arguments passed to it and calls add-triple which does the work. > (lambda (nodel edge node2) (progn (add-triple node*' edge nodel) nodel)) cop < Creates an outpointing edge, from nodel to node2. As above but without the reversal of arguments. > (lambda (nodel edge node2) 402 September 1981 © BYTE Publications Inc Listing 4 continued: (progn (add— triple nodel edge nod<=>2) nodel>) cap ■C Creates a pair of edges one in e (lambda (nodel edge node2) (progn (cip nodel edge notlr2) (cop nodel edge node2))) sing ■C Set of nodes mho point to this node- via edges of type EDGE, here we just set up the call for the recursive helper function. > (lambda (nodel edge) (lambda (nl e u) ( c on d ((null u ) nil) ((and (eq (cadar u) e) (eq (caddar u) nl>) (cons (caar u) ( (lambda (nl e u) (cond ((null u) nil) ((and (eq (caar u) nl ) (eq (cadar u) e>) (cons (caddar u) (*.t>ng-l nl e (cdr u)))) (t (song-1 nl e (cdr u)) ) ) ) dun < Destroys a node in the universe by removing it from the UNIVERSE-NODE-LIST and the UNI Vf-RSE-EDGE-LIST. the real work is done by retripler, and remember below. > (lambda (node) (progn (setq un iverse -node -1 ist (remember node univer s e— node— 1 ist ) ) Listing 4 continued on page 404 September 1981 © BYTE Publications lnc 403 Listing 4 continued: (setq universe -edtje -1 ist (retriples node universe-edge-list) ) node ) ) remember •C Remove all ocurrences of NODE in I ) W\ . This is just a simple recursive constructor function. It £DRs down the list and CONSes together all elements which are not NODE. > (lambda (node list) (cond ((null list) nil) ((eq (car list) ncxir) (remember node (cdr list))) (t (cons (car list) (remember node (cdr list))) ) ) ) retr ip 1 es •C Remove all triples from U (the UNI v\ r -! where N is either nodel or node2. This eliminates any edges which point to or from node N. > (lambda (n u> (cond ((null u) nil) ((or (eq n (caar u>) (eq n (caddar u))) (retriples n (tdv u))) (t (cons (car u) (i-ctr-ip les n (cdr u)))))) add-tr i pie ■C Updates the global UN I VERSE-EDGE--L IS"1 to reflect the netu edge given by the triple (Nl E Nil). E points from Nl to N2. > ( lambda (nl e n2) (setq universe-edge-1 j ft (append universe— edge— 1 ist (list (list nl e n2) ) ) ) ) Text continued from page 396: Cromemco and (T.(L.C)) LISP is more complex, more powerful, and more baroque. Particularly useful is the ability to specify an arbitrary number of local variables, how each is to be initialized, and how each is to be modified at each iteration. Also, one can specify an arbitrary number of exit tests and associated exit values. Finally, an arbitrary and possibly empty sequence of expres- sions make up the loop body. Our counting example above for Cromemco and (T.(L.C)) LISP is given in listing 2b. Nonstructured Function Exits Sometimes we want a function to exit from an arbitrary number of function call levels. For example, we might design a system that always allows users to type QUIT to return to the system's top command level. The CATCH and THROW forms of Cromemco and (T.(L.Q) LISP give this capability. For example: (CATCH label expression-list) says to evaluate the expression-list, much like a PROGN. If, during that evaluation, the expression: (THROW label exit-expression-list) is evaluated, then the CATCH im- mediately returns with the value returned by treating exit-expression- list as a PROGN. This exit ignores any intervening computation or pending functions specified within the CATCH expression-list. If a THROW with the corresponding label is not evaluated, the CATCH is treated just like a PROGN. Note that the label is just an atom to establish a cor- respondence between a given CATCH and THROW. Input and Output in LISP Since LISP is a highly interactive language, an implementation must have high-quality I/O (input/ output) capabilities. A user will be involved with three similar (and often inter- changeable) aspects of I/O. First, 404 September 1981 © BYTE Publications Inc there is the common method of in- teraction with the interpreter: typing expressions and reading the results. Second, there are the techniques of saving and restoring disk files con- taining programs and data. Third, there are the input and output opera- tions that happen during user- function execution. The distinctions here are somewhat arbitrary. Since the difference be- tween program and data is explicitly not enforced in LISP, it is easy to create functions that, for instance, write themselves onto disk. In fact, a common way to load programs is to redefine the source of expressions for the "driver" as a disk file rather than the keyboard. For the sake of clarity, though, we discuss the three aspects of I/O mentioned above as separate topics. Terminal I/O in all three LISPs leaves something to be desired. muLISP allows for CP/M-style within-the-line editing during input. It recognizes tX (control-X) as rubout; IR as retype line; tU as abort line. It has the usual backspace and delete characters. If the user, while typing an expression, goes beyond one line of text, the system does not reprompt the user. This is especially important if the user is not sure if the form he or she is typing is correct (in terms of matching parentheses). The user has no indication from the system that it is expecting more input rather than executing the desired ex- pression. Cromemco and (T.(L.C)) LISP ac- cept input in an immediate mode. When appropriate, they do not wait for a carriage return to accept a legal expression. Unfortunately, they allow no within-the-line editing ex- cept for backspacing. On a hard-copy terminal, this can be extremely frustrating. On a video terminal, this would not be a serious problem. Cromemco and (T.(L.Q) LISP have very flexible and easy-to-use read-macro capabilities. The input routines are table-driven in such a way that the user can easily redefine the meaning of any ASCII (American Standard Code for Information Inter- change) character, even to the point of causing the system to invoke a Text continued on page 407 Listing 5: A set of LISP expressions used to conduct the benchmarks of table 2. "/. Expressions to set up the basic benchmarks X (SETS LC (BUILD-LONG--CGNS 50 'A)) (SETQ DC ( B U I L D - D E E P - C N S 5 ' A ) ) (SETG) LONG CEVAL LC ) ) (SETQ DEEP (EVAL DC) ) > X increment the count % )) Listing 5 continued on page 406 September 1981 © BYTE Publications lnc 405 Listing 5 continued: X The next four definitions are helpers to enter the data "/„ X base. DF is the Cromemco and (T.(L.C)) LISP function X X to define call-by name? no-spread functions. DE defines X X a call-by-value spread function* % (DF F (X) (FIRST-BORN (CAR X) (CADR X)>) (DF B (X) (BORN (CAR X) (CADR X) (CADDR X) (CADDDR X))) (DF M (X) (MARRIED (CAR X) (CADR X))) (DF C (X) (C-l (CAR X) (CADR X) (CDDR X))) (DE C-l (PI P2 CS-LIST) (COND ((NULL CS-LIST) NIL) (T (CONS (BORN (CAR CS-LIST) PI P2 (CADR CS-LIST)) (C-l PI P2 (CDDR CS-LIST)))))) "/. The following expressions enter the BAGGINS and 7. X TOOK family trees. X. (MARRIED (F BALBO-B MALE) (F BERYLLA-BOFFIN FEMALE) ) (C BALBO-B BERYLLA-BOFFIN MUNGO-B MALE PANSY-B FEMALE PONTO-B MALE LARGO-B MALE LILY-B FEMALE) (MARRIED (F LAURA-GRUBB FEMALE) (QUOTE MUNGO-B)) (C LAURA-GRUBB MUNGO-B BUNGO-B MALE) (MARRIED (F BELLADONNA-TOOK FEMALE) (QUOTE BUNGO-B)) (C BELLADONNA-TOOK BUNGO-B BILBO-B MALE) (MARRIED (F TANTA-HORNBLOWER FEMALE) (QUOTE LARGO-B)) (C TANTA-HORNBLOWER LARGG-B FOSCO-B MALE) (MARRIED ( F R U B Y •- B L G E R F E M A I... E ) (QUO T E F S C - B ) ) (C RUBY-BOLGER FOSCO-B DROGO-B MALE) (MARRIED (F PRIMULA-BRANDYBUCK FEMALE) (QUOTE DROGO-B)) (C PRIMULA-BRANDYBUCK DROGO-B FRODO-B MALE) (MARRIED (F THE-OLD-TOOK MALE) (F ADAMANTA-CHUBB FEMALE)) ( C THE-OLD-TOOK A D A M A N T A - C H U B B B E I... I... A D N N A - T K F E M A L E M I R A B E I... I... A - T K F E M A I... E ) (MARRIED (QUOTE MIRABELLA-TOOK ) (F GORBADOC-BRANDYBUCK MALE)) (C MIRABELLA-TOOK GORBADOC-BRANDYBUCK PRIMULA-BRANDYBUCK FEMALE) A. 406 September 1981 © BYTE Publications Inc Text continued from page 405: MACRO form when it sees a given character. Although it is possible to redefine the READ function in muLISP, it is not as convenient as the read-macro capability described above. An exam- ple of the usefulness of read-macros is: 'expression which, in (T.(L.C)) and Cromemco LISP, will be transformed into: (QUOTE expression) Not only is this not done for you in muLISP, it is not easy to change the system to do it. To overcome the lack of a read- macro capability, muLISP provides auto-quoting. This means that any atom not bound to a value is bound to itself as a value. This is normally done for numbers (the value of " 3" is three), but most LISP systems raise an error when asked for the value of an undefined atom. The consequences of this are discussed further in the sec- tion on error handling. Disk I/O Basically, programs are stored on disk as text files or "internal image" files. Text files here are simply ASCII files of function definitions, atom values, and function calls in the same "free-format" style used when typing at the console. Internal image files are "snapshots" of the memory taken at the time they were created, including all the bindings of values that were in effect. muLISP compresses all active data structures that define the en- vironment and generates a coded file that can be loaded with the execution system. The other two LISPs take ad- vantage of the SAVE utility of CP/M and CDOS. They exit to the operating system, and the user must explicitly SAVE a memory image of the entire user area. In muLISP, the internal image files can also be brought in, using LISP functions. Restoring an environment in this way is fast, but it will explicitly destroy any environment (bindings) that were in effect at the time of the load. In the other LISPs, one is actually reloading memory with the exact contents it had at the time of the exit. This, again, is done through CP/M or CDOS and cannot be done from LISP. On the other hand, (T.L.C)) LISP and Cromemco LISP both have an auto-load feature not available in muLISP. This feature, while com- plicated to use, allows the program- mer to store functions on disk as part of a large virtual memory. Functions can be stored and loaded only if ac- tually needed (called). After the ex- ecution of the function, the system can reclaim the space it occupied (NOKEEP or SMASH), or the func- tion can remain resident (KEEP or NOSMASH) after its first access. Program-controlled I/O in all three LISPs is surprisingly easy, partly because the LISP language allows the programmer to treat programs as data. Still, "CP/M-compatible" disk I/O is generally a messy subject at best, and all three of these LISPs do an exceptional job of hiding the gory details from the programmer. Space Management Since data structures in LISP are dynamic (ie: their size changes during program execution), it is generally a good idea to have dynamic realloca- tion of memory space in a LISP system. This means that there is no a priori limit on the number of variables, functions, or strings. Rather, as more space is needed for one kind of object, it is found at the expense of space available for other kinds of objects. Cromemco and (T.(L.C)) LISP ac- complish dynamic allocation by a technique in which memory is broken into 256 pages of 256 bytes each. Any of these pages can, in theory, be used for storage of any data type. But the entire page is always used for the same type of object. This scheme has two major advantages. First, it simplifies type checking. The high byte of any object's address defines the type of that object as well as iden- tifying its location. The page-byte-to- type correspondence is kept in a table in memory. This table allows for the second advantage. If more space for a ADA™ A NEW BEGINNING pragma ; type is ; subtype is ; raise ; abort case is when = end case; access ; with use return ; record end record; exit when ; when - if then elseif else end if; case is when ; delay for in reverse loop end loop; while loop ; entry procedure in out is begin exception end; return function in out return; select else end select; loop accept do end; task body is begin exception end select accept or delay end select; task is end package is private end; for use record end record ADA/M - Compiles ADA program for Host system execution. Excellent for learning ADA and converting existing programs. Includes ADA Compiler and Compiler ADA Programming Support Environment (CAPSE) $495. ADA/C - Compiler and Kernal APSE (KAPSE) for CP/M® $995. ADA Programmers Manual $25. ADA Syntax Reference Card $6. Specify exact configuration and operating system. Courses are available for compiler customers to learn the most powerful and complex software language. ADA. Credit for purchase of ADA/M will be given toward purchase of larger ALS. Royalty will be paid to customers who convert existing programs into ADA for inclusion in the ALS, ADA Language System library. DIGITAL ELECTRONIC SYSTEMS, INC. Box 5252, Torrance, California 90510 213/539-6239 ADA Is a registered trademark of Dept. i ■egistered tradem of Digital fiese; Circle 112 on inquiry card. September 1981 © BYTE Publications Inc. 407 given type of object is needed, a page of memory is allocated by simply changing the entry in the table for an unused page. If, on the other hand, an allocated page is made free (by the garbage-collection process), a change to the table allows this space to be claimed by another data type. Unfortunately, the stack, which is used for both variables and control information, must use a contiguous area of memory if it is to be fast. This means that when the stack is full the system cannot allocate an arbitrary free page of memory to the stack. A solution to this would be to move other data around to free up a page adjacent to the stack. But, with the pointer conventions discussed above, this would be a very messy and time- consuming job. Therefore, Cromem- co and (T.(L.C)) LISP use a fixed-size stack. This decision poses a real prob- lem because recursive-style and iterative-style programming make very different demands on the size of the stack. In fact, curiously, the stack size is fixed regardless of the total memory size of the system. Collector Edition T The Byte covers shown below are available as beauti- ful Collector Edition Prints. Each full color print is 1 1" x 14", including a V/s" border, and is part of an edition strictly limited to 500 prints. (Print numbers 2. 4. 6, 7 and 8 are editions of only 100 prints, and some quantities are very low.) The artist. Robert Tinney has personally inspected, signed and numbered each print. A Certificate of Authen- ticity accompanies each print guaranteeing its quality and limited number Collector Edition Prints are carefully packaged flat to avoid bending, and are shipped first class. The price of each print is $20, plus $3 per shipment for postage and handling ($6 overseas). Collector Prints 9-12 are available as a set of 4 for $70 Because certain prints have sold out, Sets 1-4 and Sets 5-8 are no longer available as sets To order your own beautiful Collector Edition Byte Cover use the convenient coupon below Visa or Master- Card orders may call Toll Free. '9 SOFTWARE PIRACY $20 M0 THE PROGRAMMING ROUTE S20 *2 FUN AND GAMES S20 PERSPECTIVES #4 SOFTWARE MIRAGE S20 '12 FUTURE PAST "R w k^- J* #6 TOTAL ECLIPSE *7 COMPUTER HARDWARE S20 ALSO AVAILABLE are the prints ■■■■ WM shown at left. "Computer Chess" Is ^^^H i an 18" X 22" tuil color poster. "Through the Trap Door" and ^H ■ l Each print is 18" X 2Z", and is 0fM accompanied by its awn Certificate of Authenticity. H both "Door" and "Barrier" are ordered, a special price of $55 applies. COMPUTER CHESS THROUGH THE BREAKING THE All three prints shown at left are Oct. 1978 TRAP DOOR SOUND BARRIER shipped lirst class In heavy duty $7.95 Mar, 1979 $36.00 Sept. 1977 $35.00 mailing tubes. QTY TITLE AMOUNT s . $ Sat 9-12 Both "Trap Door" & "Barrier" Post. & Hand. (S3 U.S.. S6 overseas) $70 S TOTAL s □ I have enclosed check or money order n Visa □ MasterCard Card # _ _ Expiration Date SHIP MY PRINTS TO: Name Address State Zip. Wail this coupon to: I robert tinney graphics J 1864 N. Pamela Onve ' Baton Rouge, LA ' 70815 I muLISP uses a truly dynamic scheme. At any time, all data types are competing for memory. As demands for one type increase, the other spaces shrink. Because this in- cludes the stack, space is better used in this system. The cost of this feature is, of course, time. The user must wait for data areas to be moved around during program execution. However, we found the time penalty to be minimal. Linking muLISP and Cromemco LISP both support user-defined assembly- language functions. The current ver- sion of (T.(L.C)) LISP apparently does not. Assembly-language routines allow the user to extend his or her LISP system in various ways. Special functions can be made to run significantly faster, or functions can be written to take advantage of special hardware such as a color graphics screen. The Cromemco LISP system gives the user extensive, if obtuse, documentation and several support programs to allow the user to build assembly-language routines that are linked into the LISP system. Once a linked system is created, it can be saved as an internal image file and then used as the regular LISP system. The muLISP solution is less am- bitious but still workable. muLISP allows up to four assembly-language routines to be incorporated into the system. The routines must be called by jump instructions located in fixed addresses in memory, and the bodies of the routines must exist in locations "invisible" to LISP — that is, above the operating system, Since the routines are not in the LISP area, sav- ing an internal image file of muSTAR will not allow the user to reload the linked system. Rather, the system must be regenerated each time it is used. This could be done in a straightforward way using a CP/M command file. User Environment muLISP exhibits an approach to the environment presented by the LISP system that differs from the 408 September 1981 © BYTE Publications Inc other two LISPs. One example of this is the idea of having a separate development environment as well as an execution environment. A development environment supports editing and debugging of functions (programs) in an interactive setting. While development and testing can be done in muLISP's execution system, there are no facilities to make this easy. Another example of the dif- ference is the related stance on error handling, which is discussed below. The development subsystem, muSTAR, is an internal image file which is delivered with the muLISP system. (It is an application program written in LISP.) muSTAR is a menu- based program that allows for the user to pick any of the following options: • Edit Function • Edit Variable • Edit Property • EvalLISP • Eval-QuoteLISP • Trace Function • Untrace Function • Read File • Write File • Select Drive Menu-based systems are generally designed to be used with video ter- minals. This one is no exception: it is a joy on the screen of a 9600 bps ter- minal and very frustrating on a 300 bps DECwriter. The editor that comes with muSTAR is a flexible screen editor in- tended to be adaptable to any type of video terminal. Unfortunately, the "interrupt execution" character, Escape, is used by some terminals for cursor control. Since Escape is detected at a very low level in the system, there is no way to tailor the screen editor to use these terminals. Unlike some LISP "structure" editors that use atoms and expressions as the units to be modified, the muSTAR editor is a conventional character- oriented screen editor; however, it is convenient and easy to use. When functions are being edited, the text is pretty-printed to make it easier to read and edit. The Trace and Untrace facilities allow the user to specify to the muSTAR system that when a given function is called the system should print its arguments before the execu- tion of the function and the result afterward. This is the single most im- portant tool for the user in the pro- cess of debugging and developing programs. Read and Write are for text files and assume a CP/M file extension of ".LIB". The files can be created either by muSTAR or by an external editor. Read works in the obvious way. Write, however, writes out only func- tions and variables whose names ap- pear on the property list of the atom that is the name of the file. While this can be done using the Edit Property function of muSTAR, it is easy to forget to add new function names during a session and thus lose your work when you exit the muSTAR system. The error-handling facility in muLISP is virtually nonexistent. The three "advisory" messages: ZERO DIVIDE ERROR, END-OF-FILE READ, and NO DISK SPACE are printed at the console, and the ««r •a**™ 8 080 ***** atS» v .m^**t::*» tafc© ssP< ^^O^^'sea^ «s*-^ Z80 ,s =a -Vt* ■red"" 9 " f"**^* 8 * Circle 374 on inquiry card. September 1981 © BYTE Publications Inc 409 offending primitive function is forced to return NIL. Execution of the rest of the user function proceeds, according to the manual, "normally." The only error that causes termination of ex- ecution is INSUFFICIENT MEMORY SPACE. When execution stops, as when the Escape key is typed, the user has four options. He or she can continue execution, go back to the top-level driver, restart muLISP, or go back to the CP/M system. Unfor- tunately, the user cannot examine the functions or arguments that caused the problem. Because of the autOTquoting and implicit-sequence-evaluation features of the system, there are no other errors that can occur during program execution. In fact, since evaluation of any syntactically legal expression is defined, and the input routines for the driver loop ensure that only legal ex- pressions are read in, the user cannot cause any error other than the ones listed above. Although this may be an elegant concept, it makes debugging awkward at best and virtually im- possible at worst except for the Trace SAVE BIG BUCKS Model II 64K $3395 26-4160 1 Drive Exp $10: 26-4161 2 Drive Exp 1559.00 26-4162 3 Drive Exp 2099.00 26-4530 Scripsit II 259.00 26-1061 4K I . . , 26-4512 Profile II 159.00 26-1062 16K III 26-451 1 Visicalc II 259.00 26-1063 32K III 26-4501 Gen Ledger 179.00 26-4506 Mail List 72.00 MODEL III W/2 Drives, RS 232 26-1162 1st Drive ... 5 599.00 . 859.00 2225.00 . 765.00 IDS PAPER TIGERS Dot Resolution Graphics quality print IDS 445G 7 wire printhead, graphics (List $ 985) $ 795.00 IDS 460G 9 wire printhead, graphics (List 1094) 886.00 IDS 560G 9 wire, wide carriage, graphics. . . (List 1394) 1129.00 Model I 26-1140 Expansion Interface $249.00 26-1141 16K Exp. Interface 359.00 26-1142 32K Exp. Interface 469.00 26-1145 RS 232C Board 84.00 26-1160/1 Mini Disk Drive 419.00 26-1563 Scripsit-Disk 79.00 26-1566 Visicalc 83.00 PRINTERS 26-1167 m Line Printer VII .... $ 360.00 26-1166 Line Printer VI 1080.00 26-1158 Daisy Wheel II 1798.00 26-1165 Line Printer V 1710.00 26-1401 Cable 36.00 Color Computer 4K $353 26-3001 4K $353.00 26-3002 16K Ext. Basic 533.00 26-3009 Joysticks 22.50 26-3010 Color Video 353.00 26-1206 Recorder 54.00 All prices are subject to change without notice. Freight, handling, and insurance charges are extra. Most items are shipped United Parcel Service. Model II and other hardware weighting over 50 lbs. is ship- ped freight collect by truck. Certified Check for immediate shipment from stock. Master Charge, Visa or Bank Card add 3% surcharge. Vern Street Products 114 West Taft Sapulpa, Ok 74066 The Computer Store, Inc. 4949 South Peoria Tulsa, Ok 74105 918-747-9333 option available in muSTAR. Since this is not available in the core muLISP system, you would always do development in muSTAR. Cromemco LISP and (T.(L.C)) LISP take a more traditional attitude to the user environment and error handling. Errors are flagged in many situations. In particular, the errors UNDEFINED VARIABLE and WRONG NUMBER OF ARGUMENTS, as well as data-type violations, are checked for during program evaluation. The characters G, Control-G, and Bell act like the Escape key in muLISP to end execu- tion of user functions. In addition, the function ERROR can be called by a function at any time. Once an error occurs, evaiuation stops, a message is printed, and the user has several options. He or she can examine the function or arguments that caused the error, trace the execution stack back through all the nested calls, or "pop" up the stack (to the top or any intermediate place) giving a return value for the function that was called at that level. Although these functions are a good idea, they are poorly explained in the manual. Documentation, Library Software We were very pleased with the quality of the documentation for all three LISPs. Because Cromemco and (T.(L.C)) LISP are just different ver- sions of the same program, the two user's manuals are almost identical. These manuals begin with a long discussion of LISP style and philosophy and include a discussion of how to code a recursive descent parser in LISP. This background in- formation is quite good and will be a great help to a beginner. Most of the function descriptions include an il- lustrative example. The Cromemco LISP manual adds a section on the in- ternal representation of data struc- tures and gives information needed to link to assembly-language subroutines. The (T.(L.Q) LISP manual includes some annotated LISP examples adapted from Ar- tificial Intelligence Programming (see the 'Where to Learn LISP" text box for a description of this book and 410 September 1981 © BYTE Publications Inc Circle 81 on inquiry card. other useful LISP information). These examples are prefaced by a discussion of the differences between (T.(L.Q) LISP and the LISP used in Artificial Intelligence Programming. We found this discussion quite useful. Both manuals are about 135 pages long. The muLISP manual, which is about 100 pages long, is shorter and terser, but of high quality. This manual gives a limited amount of background information. The func- tion descriptions are in a formal metalanguage that is complete but often obscure. These descriptions would be much clearer if they includ- ed examples. The manual includes commented listings of many useful utilities and the muSTAR develop- ment environment, and they will be quite useful for users who wish to tailor their LISP environment. In par- ticular, there are instructions for tailoring the muLISP screen editor to different kinds of terminals. Cromemco LISP is distributed with a fairly complete set of Cromemco software, including the CDOS operating system, several CDOS utilities, and a screen editor. Unfor- tunately, the screen editor can only be used with a Cromemco terminal. This is downright unfriendly of Cromemco, particularly since it is trivial to provide the "hooks" to do screen editing with almost any modern terminal. Also provided are files with LISP utilities, a trace func- tion, a pretty-printer program, ex- amples from Artificial Intelligence Programming, and examples of the more esoteric features of Cromemco LISP. (T.(L.C)) LISP is distributed with the same example and utility files as Cromemco LISP. Also included are several additional files of examples. muLISP is distributed with the muSTAR utility and the other utilities described in the manual. Also includ- ed are several games and programs, including a version of Weizenbaum's ELIZA, called DOCTOR, and a guessing game which learns, called ANIMAL. muLISP has the beginnings of an active user group and software library. Information about the user group and the software is published in a small newsletter available to muLISP purchasers. (T.(L.C)) LISP purchasers also receive a newsletter, though it is less formal and less regular. As of now, there is no (T.(L.C)) LISP users' group. Conclusions • Cromemco and (T.(L.C)) LISP have many modern features, yet they still run acceptably fast. The auto-load feature potentially allows very large programs to run in a virtual-memory environment. The documentation is quite good and would be useful for LISP beginners. Cromemco LISP also includes information that would be useful to someone adding his or her own machine-language subroutines. A major drawback of these LISPs is a small, fixed-sized stack that severely limits the use of recursive functions. (T.(L.Q) LISP is the cheapest of the LISPs reviewed here — $150. Cromemco LISP, with only a small amount of additional functionality, is the most expensive — $295. • muLISP is an extremely fast LISP with a complete but basic set of ATTENTION S-1 00 USERS, OEMs & ISOs! MM-103 IS THE ONLY MODEM FOR YOUR NEEDS! In previous issues, we listed more than 50 reasons why PMMI MM-103 modems are superior, along with a list of satisfied users that is now too long to print. Quality, integrity and low cost have made the MM-103 America's most popular modem. PMMI was the first to gain FCC approval and meet IEEE-696 S-100 standards. You won't find another modem for the S-1 00 bus with a wider range of Baud rates, more extensive and controllable software and such an unbeatable warranty. And since PMMI has eliminated the need for an acoustic coupler or an RS 232 adapter, your connection is more reliable and you buy no unnecessary hardware. SO DON'T DELAY! GO WITH THE MODEM WITH EXPERIENCE! $w$> COMMUNICATIONS [POTOMAC MICRO-MAGIC, INC.] For further information, call or write: Three Skyline Place 5201 Leesburg Pike, Suite 604 Falls Church, VA 22041 [703] 379-9660 Or dial into our 24 hour-a-day Modem Test Center: [703] 379-0303 |300Baud| AFTER All... ALL MODEMS ARE NOT CREATED EQUAL! Circle 296 on Inquiry card. September 1981 © BYTE Publications Inc 411 features. It is distributed with muSTAR, a nice LISP development environment that includes a screen editor. The documentation is good, but it is too terse and formal for beginners. Much of the speed of muLISP comes from features that make programs hard to read and hard to debug. In particular, muLISP does almost no type checking or error detection. • LISP is alive and well and living in a Z80 microprocessor. Although there are great differences between muLISP and the other two packages, we feel that all three are successful products. Each would allow a user to develop and use fairly large LISP programs. ■ Acknowledgments The benchmark tests were performed on a system purchased and supported by Army Research Office grant DAAG29-79-G-0046. We would like to thank E Jeffrey Conklin and Caxton C Foster, Where to learn LISP: Recommended Books and Articles 1. Allen, J. Anatomy of LISP. New York: McGraw-Hill Book Co, 1978. An examination of many issues in computer science through LISP-tinted spectacles. This is also the only published discussion of many modern LISP implementation techniques and styles. 2. Allen, J. "An Overview of LISP" in BYTE, August 1979, page 10. A com- pact overview to LISP style and usage. All the important LISP functions are discussed. The most difficult aspect of learning LISP is understanding exactly when and how values get bound to names. These issues are not discussed. 3.Charniak, Eugene, Christopher Riesback, and Drew McDermott. Ar- tificial Intelligence Programming. Hillsdale NJ: Lawrence Erlbaum Associates, 1979. A very complete in- troduction to sophisticated uses of LISP for AI programming. The first few chapters do a good job of explain- ing the name-value-binding issues. 4.Friedman, Daniel. The Little LISPer. London, England: Science Research Associates Inc, 1974. An entertaining introduction to the style of LISP pro- gramming. This book does not cover everything you need to know to use LISP on a real machine. It, again, avoids key issues of how and when LISP names get values. 5. McCarthy, John. "Recursive Func- tions of Symbolic Expressions and Their Computation by Machine," Communications of the Association for Computing Machinery, pages 184 through 195, April 1960. This is where it all started, the article that suggested that the mathematical lambda calculus could be embodied in a programming language. 6. Winston, Patrick Henry. Artificial Intelligence. Reading MA: Addison- Wesley, 1977. An easily understood in- troduction to AI and AI programming. 7.Winston, Patrick Henry and Ber- thold Klaus Horn. LISP. Reading MA: Addison- Wesley, 1981. A pleasant, chatty introduction to LISP. SciTronics introduces . . . REAL TIME CLOCKS 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 owners RTC-100 $159 RTC-A $129 RC-80CK $109 send SciTronics Inc. check or 52 3 s C i eweU St-] p o. Box 5344 ordeMo- 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. 412 September 1981 © BYTE Publications Inc BYTE's Bits Microsoft Drops APL Interpreter Microsoft has dropped work on an APL interpreter. The demand of other projects has caused the company to stop work on the interpreter for 8-bit microcomputers. The company still plans to develop a 16-bit version. BYTE's Bugs Price Mis-Steak In the April 1981 "Software Received," the price of the "Beef Cattle Least-Cost Ration Program" was incorrectly listed. The correct price is $495. A demonstra- tion tape of the program is available for $5. For information on the program, con- tact Agricultural Software Consultants, 1706 Santa Fe, Kingsville TX 78363 (512) 595-1937. ■ Circle 322 on Inquiry card. Do more with your Commodore. Plug in the printer that business professionals prefer. Discover the quality difference and move up to Mannesmann Tally printing. The high speed 8024 serial printer comes ready to plug into and work with your Commodore system. No fussing with convertors or adapter boxes. Here's what you get. Print speeds up to 200 lines per minute. Full 132 column printing. 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BYTE September 1981 413 The Emperor's Old Clothes Charles Antony Richard Hoare Oxford University, England The 1980 A CM Turing Award was pre- sented to Charles Antony Richard Hoare, Professor of Computation at Oxford University, England, by Walter Carlson, chairman of the awards committee. The presentation took place at the ACM An- nual Conference in Nashville, Tennessee, October 27, 1980. Professor Hoare was selected by the General Technical Achievement Award Committee for his fundamental contribu- tions to the definition and design of pro- gramming languages. His work is charac- terized by an unusual combination of in- sight, originality, elegance, and impact. He is best known for his work on axio- matic definitions of programming lan- guages through the use of techniques pop- ularly referred to as axiomatic semantics. He developed ingenious algorithms such as Quicksort and was responsible for in- venting and promulgating advanced data- structuring techniques in scientific pro- gramming languages. He has also made important contributions to operating sys- tems through the study of monitors, and his most recent work is on communicating sequential processes. Before his appointment to Oxford in 1977, Professor Hoare was Professor of Computer Science at The Queen's Univer- sity in Belfast, Ireland, from 1968 to 1977, and was a Visiting Professor at Stanford University in 1973. From 1960 to 1968 he Acknowledgments BYTE wishes to thank Professor CAR Hoare and the Association for Computing Machinery for granting us permission to reprint this arti- cle, which originally appeared in the February 1981 Communications of the ACM. Copyright 1981 by the Association for Computing Machinery, Inc. Reprinted by permission. Professor Charles Antony Richard Hoare held a number of positions with Elliot Brothers Ltd, England. Professor Hoare has published exten- sively and is on the editorial boards of a number of the world's foremost computer science journals. In 1973 he received the ACM Programming Systems and Lan- guages Paper Award. Professor Hoare became a Distinguished Fellow of the British Computer Society in 1978 and was awarded the degree of Doctor of Science Honoris Causa by the University of Southern California in 1979. The Turing Award is the Association for Computing Machinery's highest award for technical contributions to the computing community. It is presented each year in memory of Dr A M Turing, an English mathematician who made many important contributions to the com- puting sciences. A transcript of Professor Hoare s 1980 Turing Award Lecture follows. My first and most pleasant duty in this lecture is to express my profound gratitude to the Association for Com- puting Machinery for the great honor which they have bestowed on me and for this opportunity to address you on a topic of my choice. What a dif- ficult choice it is I My scientific achievements, so amply recognized by this award, have already been amply described in the scientific literature. Instead of repeating the abstruse technicalities of my trade, I would like to talk informally about myself, my personal experiences, my hopes and fears, my modest suc- cesses, and my rather less modest failures. I have learned more from my failures than can ever be revealed in the cold print of a scientific article, and now I would like you to learn from them, too. Besides, failures are much more fun to hear about after- wards; they are not so funny at the time. I start my story in August 1960, when I became a programmer with a small computer manufacturer, a divi- sion of Elliott Brothers (London) Ltd, where in the next eight years I was to receive my primary education in computer science. My first task was to implement for the new Elliot 803 computer a library subroutine for a new fast method of internal sorting just invented by Shell. I greatly en- joyed the challenge of maximizing ef- ficiency in the simple decimal-ad- 414 September 1981 © BYTE Publications Inc dressed machine code of those days. My boss and tutor, Pat Shackleton, was very pleased with my completed program. I then said timidly that I thought I had invented a sorting method that would usually run faster than SHELLSORT, without taking much extra store. He bet me sixpence that I had not. Although my method was very difficult to explain, he final- ly agreed that I had won my bet. I wrote several other tightly coded library subroutines, but after six months I was given a much more im- portant task — that of designing a new advanced high-level programming language for the company's next com- puter, the Elliott 503, which was to have the same instruction code as the existing 803 but run sixty times faster. In spite of my education in classical languages, this was a task for which I was even less qualified than those who undertake it today. By great good fortune there came into my hands a copy of the Report on the In- ternational Algorithmic Language ALGOL 60. Of course, this language was obviously too complicated for our customers. How could they ever understand all those begins and ends when even our salesmen couldn't? Around Easter 1961, a course on ALGOL 60 was offered in Brighton, England, with Peter Naur, Edsger W Dijkstra, and Peter Landin as tutors. I attended this course with my col- league in the language project, Jill Pym, our divisional Technical Manager, Roger Cook, and our Sales Manager, Paul King. It was there that I first learned about recursive proce- dures and saw how to program the sorting method which I had earlier found such difficulty in explaining. It was there that I wrote the procedure, immodestly named Quicksort, on which my career as a computer scien- tist is founded. Due credit must be paid to the genius of the designers of ALGOL 60 who included recursion in their language and enabled me to describe my invention so elegantly to the world. I have regarded it as the THE FORMULA allows the computer professional to focus on the most important part of business: the needs of the client. 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In that design I adopted cer- tain basic principles which I believe to be as valid today as they were then. Principles of Design The first principle was security, the principle that every syntactically in- correct program should be rejected by the compiler and that every syntac- tically correct program should give a result or an error message that was predictable and comprehensible in terms of the source language program itself. Thus no core dumps should ever be necessary. It was logically im- possible for any source language pro- gram to cause the computer to run wild, either at compile time or at run time. A consequence of this principle MEMOREX WHEN YOU ADD IT UP, MEMOREX FLEXIBLE DISCS FROM PACIFIC EXCHANGES ARE YOUR BEST BUY. 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The second principle in the design of the implementation was brevity of the object code produced by the com- piler and compactness of run time working data. There was a clear reason for this: the size of main stor- age on any computer is limited, and its extension involves delay and ex- pense. A program exceeding the limit, even by one word, is impossible to run, especially since many of our cus- tomers did not intend to purchase backing stores. This principle of compactness of object code is even more valid today, when processors are trivially cheap in comparison with the amounts of main store they can address, and backing stores are comparatively even more expensive and slower by many orders of magnitude. If as a result of care taken in implementation the available hardware remains more powerful than may seem necessary for a particular application, the appli- cations programmer can nearly always take advantage of the extra capacity to increase the quality of his program, its simplicity, its rugged- ness, and its reliability. The third principle of our design was that the entry and exit conven- tions for procedures and functions should be as compact and efficient as for tightly coded machine-code sub- routines. I reasoned that procedures are one of the most powerful features of a high-level language, in that they 416 September 1981 © BYTE Publications Inc Circle 280 on inquiry card. both simplify the programming task and shorten the object code. Thus there must be no impediment to their frequent use. The fourth principle was that the compiler should use only a single pass. The compiler was structured as a collection of mutually recursive procedures, each capable of analyz- ing and translating a major syntactic unit of the language — a statement, an expression, a declaration, and so on. It was designed and documented in ALGOL 60, and then coded into deci- mal machine code using an explicit stack for recursion. Without the ALGOL 60 concept of recursion, at that time highly controversial, we could not have written this compiler at all. I can still recommend single-pass, top-down recursive descent both as an implementation method and as a design principle for a programming language. First, we certainly want programs to be read by people, and people prefer to read things once in a single pass. Second, for the user of a time-sharing or personal computer system, the interval between typing in a program (or amendment) and starting to run that program is wholly unproductive. It can be minimized by the high speed of a single-pass com- piler. Finally, to structure a compiler according to the syntax of its input language makes a great contribution to ensuring its correctness. Unless we have absolute confidence in this, we can never have confidence in the re- sults of any of our programs. Principles at Work To observe these four principles, I selected a rather small subset of ALGOL 60. As the design and imple- mentation progressed, I gradually discovered methods of relaxing the restrictions without compromising any of the principles. So in the end we were able to implement nearly the full power of the whole language, includ- ing even recursion, although several features were removed and others were restricted. In the middle of 1963, primarily as a result of the work of Jill Pym and Jeff Hillmore, the first version of our compiler was delivered. After a few months we began to wonder whether anyone was using the language or taking any notice of our occasional reissue, incorporating improved op- erating methods. Only when a customer had a complaint did he con- tact us, and many of them had no complaints. Our customers have now moved on to more modern computers and more fashionable languages, but many have told me of their fond memories of the Elliott ALGOL Sys- tem. The fondness is not due just to nostalgia, but to the efficiency, re- liability, and convenience of that early simple ALGOL System. As a result of this work on ALGOL, in August 1962 I was invited to serve on the new Working Group 2.1 of the International Federation of Information Processors (IFIP) charged with responsibility for maintenance and development of ALGOL. The group's first main task was to design a subset of the language which would remove some of its less successful fea- tures. Even in those days and even with such a simple language, we rec- ognized that a subset could be an im- provement on the original. I greatly welcomed the chance of meeting and hearing the wisdom of many of the original language designers. I was astonished and dismayed at the heat and even rancor of their discussions. Apparently the original design of ALGOL 60 had not proceeded in that spirit of dispassionate search for truth which the quality of the language had led me to suppose. In order to provide relief from the tedious and argumentative task of de- signing a subset, the working group allocated one afternoon to discussing the features that should be incor- porated in the next design of the lan- guage. Each member was invited to suggest the improvement he consid- ered most important. On October 11, 1963, my suggestion was to pass on a request of our customers to relax the ALGOL 60 rule of compulsory decla- ration of variable names and adopt some reasonable default convention such as that of FORTRAN. I was astonished by the polite but firm re- jection of this seemingly innocent suggestion. 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S-BASIC is a trademark of Topaz Programminp PASCAt/MT- Isalrademcxk of MT Microsystems September 1981 © BYTE Publications Inc 417 best protection against programming and coding errors which could be ex- tremely expensive to detect in a run- ning program and even more expen- sive not to. The story of the Mariner space rocket to Venus, lost because of the lack of compulsory declarations in FORTRAN, was not to be pub- lished until later. I was eventually persuaded of the need to design pro- gramming notations so as to max- imize the number of errors which can- not be made, or if made, can be re- liably detected at compile time. Perhaps this would make the text of programs longer. Never mindl Wouldn't you be delighted if your Fairy Godmother offered to wave her wand over your program to remove all its errors and only made the condi- tion that you should write out and key in your whole program three times? The way to shorten programs is to use procedures, not to omit vital declarative information. Among the other proposals for the development of a new ALGOL was that the Switch declaration of ALGOL 60 should be replaced by a more general feature, namely an ar- BOOKKEEPING MADE SIMPLE r GENERAL LEDGER FUNCTIONS 1 ACCOUNTS PAYABLE 1 Set- Up & Review Accounts 40 Payables Ledger 2 Post to General Ledger 41 Write Payable Checks 3 Close Month/Year 42 Accounts Payable Labels 4 Daily Journal 5 Monthly Journal ACCOUNTS RECEIVABLE 6 Monthly Detail Report 50 Receivable Ledger 7 Trial Balance 51 Customer Billing 8 Income Statement 52 Receivable Aging 9 Balance Sheet 63 Interest Add-On 10 Chan of Accounts 54 Receivable Labels PAYROLL FUNCTIONS SPECIAL FUNCTIONS 20 Adjust Tan Tables 60 Initialization 21 Payroll Ledger 61 Index Update 22 Write Payroll Checks 62 Update 6 Post to Files 23 Print W-2 63 Special Directories 24 Initialize New Pay Period 64 General Directory 65 Adiust Budget 66 Comparative Budget Reoon 30 CALL OPTIONAL TASKS MENU 67 Call End ol Session .a The Menu THE BOOKKEEPER SYSTEM™ Dealer Inquiries Welcome "A Combined General Ledger, Accounts Payable, Accounts Receivable, and Payroll -Expandable to Include Inventory, Order Entry, Certified Payroll, or Mail List -Complete Easy-To-Follow Manual and Instructions - For Microcomputers using CP/M, OASIS or TRSDOS Operating System -64 K Minimum, Hard Disk Compatible -Demonstration Disk Available CP/A4. OASIS and TRSDOS are TMs of Digital Research, Phase One Systems and Tandy Corp.. respectlve/y. (6 1 5) 452- 1 027 1 79 West Smith Street, Gallatin , TN 37066 We're Writing Programs For People ray of label-valued variables, and that a program should be able to change the values of these variables by assignment. I was very much op- posed to this idea, similar to the assigned Go To of FORTRAN, because I had found a surprising number of tricky problems in the im- plementation of even the simple labels and switches of ALGOL 60. I could see even more problems in the new feature, including that of jump- ing back into a block after it had been exited. I was also beginning to suspect that programs that used a lot of labels were more difficult to understand and get correct, and that programs that assigned new values to label variables would be even more difficult still. It occurred to me that the appro- priate notation to replace the ALGOL 60 switch should be based on that of the conditional expression of ALGOL 60, which selects between two alter- native actions according to the value of a Boolean expression. So I sug- gested the notation for a "case ex- pression" which selects between any number of alternatives according to the value of an integer expression. That was my second language design proposal. I am still most proud of it, because it raises essentially no prob- lems either for the implementer, the programmer, or the reader of a pro- gram. Now, after more than fifteen years, there is the prospect of interna- tional standardization of a language incorporating this notation — a re- markably short interval compared with other branches of engineering. Back again to my work at Elliott. After the unexpected success of our ALGOL Compiler, our thoughts turned to a more ambitious project: to provide a range of operating system software for larger configura- tions of the 503 computer, with card readers, line printers, magnetic tapes, and even a core backing store which was twice as cheap and twice as large as the main store, but fifteen times slower. This was to be known as the Elliott 503 Mark II software system. It comprised: 1. An assembler for a symbolic assembly language in which all the rest of the software was to be written. 2. A scheme for automatic ad- 418 September 1981 © BYTE Publications Inc Circle 371 on inquiry card. ministration of code and data overlays, either from magnetic tape or from core backing store. This was to be used by the rest of the software. 3. A scheme for automatic buffer- ing of all input and output on any available peripheral device, again to be used by all the other software. 4. A filing system on magnetic tape with facilities for editing and job control. 5. A completely new implementa- tion of ALGOL 60, which removed all the nonstandard restrictions which we had imposed on our first im- plementation. 6. A compiler for FORTRAN as it was then. Deadline Pressures I wrote documents which described the relevant concepts and facilities, and we sent them to existing and pro- spective customers. Work started with a team of fifteen programmers, and the deadline for delivery was set some eighteen months ahead, in March 1965. After initiating the design of the Mark II software, I was suddenly promoted to the dizzying rank of Assistant Chief Engineer, responsible for advanced develop- ment and design of the company's products, both hardware and soft- ware. Although I was still managerially responsible for the 503 Mark II soft- ware, I gave it less attention than the company's new products and almost failed to notice when the deadline for its delivery passed without event. The programmers revised their implemen- tation schedules, and a new delivery date was set some three months ahead, in June 1965. Needless to say, that day also passed without event. By this time, our customers were get- ting angry and my managers in- structed me to take personal charge of the project. I asked the senior pro- grammers once again to draw up revised schedules, which again showed that the software could be delivered within another three months. I desperately wanted to believe it, but I just could not. I disregarded the schedules and began to dig more deeply into the project. It turned out that we had failed to make any overall plans for the alloca- tion of our most limited resource — main storage. Each programmer ex- pected this to be done automatically, either by the symbolic assembler or by the automatic overlay scheme. Even worse, we had failed to simply count the space used by our own soft- ware which was already filling the main store of the computer, leaving no space for our customers to run their programs. Hardware address length limitations prohibited adding more main storage. Clearly, the original specifications of the software could not be met and had to be drastically curtailed. Ex- perienced programmers and even managers were called back from other projects. We decided to concen- trate first on delivery of the new com- piler for ALGOL 60, which careful calculation showed would take another four months. I impressed upon all the programmers involved that this was no longer just a predic- tion; it was a promise. If they found they were not meeting their promise, it was their personal responsibility to find ways and means of making good. The programmers responded magnificently to the challenge. They worked nights and days to ensure completion of all those items of soft- ware which were needed by the ALGOL compiler. To our delight, they met the scheduled delivery date; it was the first major item of working software produced by the company over a period of two years. Our delight was short-lived; the compiler could not be delivered. Its speed of compilation was only two characters per second, which com- pared unfavorably with the existing version of the compiler operating at about a thousand characters per sec- ond. We soon identified the cause of the problem: it was thrashing be- tween the main store and the exten- sion core backing store which was fif- teen times slower. It was easy to make some simple improvements, and within a week we had doubled the speed of compilation to four char- acters per second. In the next two weeks of investigation and repro- gramming, the speed was doubled again to eight characters per second. We could see ways in which within a month this could be still further im- proved, but the amount of repro- gramming required was increasing and its effectiveness was decreasing; there was an awful long way to go. The alternative of increasing the size of the main store so frequently adopted in later failures of this kind was prohibited by hardware address- ing limitations. There was no escape: the entire Elliott 503 Mark II software project had to be abandoned, and with it, over thirty man-years of program- ming effort, equivalent to nearly one man's active working life. And I was responsible, both as designer and as manager, for wasting it. A meeting of all our 503 customers was called and Roger Cook, who was then manager of the computing divi- sion, explained to them that not a single word of the long-promised software would ever be delivered to them. He adopted a very quiet tone of delivery, which ensured that none of the customers could interrupt, mur- mur in the background, or even shuf- fle in their seats. I admired but could not share his calm. Over lunch our customers were kind to try to comfort me. They had realized long ago that software to the original specifications could never have been delivered, and even if it had been, they would not have known how to use its sophisti- cated features, and anyway many such large projects get cancelled before delivery. In retrospect, I believe our customers were fortunate that hardware limitations had pro- tected them from the arbitrary ex- cesses of our software designs. In the present day, users of microprocessors benefit from a similar protection — but not for much longer. At that time I was reading the early documents describing the concepts and features of the newly announced OS 360, and of a new time-sharing project called Multics. These were far more comprehensive, elaborate, and sophisticated than anything I had imagined, even in the first version of the 503 Mark II software. Clearly IBM and MIT must be possessed of some secret of successful software de- September 1981 © BYTE Publications Ire 419 sign and implementation whose nature I could not even begin to guess at. It was only later that they realized they could not either. So I still could not see how I had brought such a great misfortune upon my company. At the time I was con- vinced that my managers were plan- ning to dismiss me. But no, they were intending a far more severe punish- ment. "OK, Tony," they said. "You got us into this mess, and now you're going to get us out." "I don't know how," I protested, but their reply was simple. "Well then, you'll have to find out." They even expressed confidence that I could do so. I did not share their con- fidence. I was tempted to resign. It was the luckiest of all my lucky escapes that I did not. Of course, the company did every- thing they could to help me. They took away my responsibility for hardware design and reduced the size of my programming teams. Each of my managers explained carefully his own theory of what had gone wrong, and all the theories were different. At last, there breezed into my office the most senior manager of all, a general manager of our parent company, An- drew St. Johnston. I was surprised that he had even heard of me. "You know what went wrong?" he shouted (he always shouted). "You let your programmers do things which you yourself do not understand." I stared in astonishment. He was obviously out of touch with present-day realities. How could one person ever understand the whole of a modern software product like the Elliott 503 Mark II software system? I realized later that he was ab- solutely right; he had diagnosed the true cause of the problem and he had planted the seed of its later solution. Defining the Problems I still had a team of some forty pro- grammers. We needed to retain the goodwill of customers of our new machine and even regain the con- fidence of the customers for our old one. But what should we actually plan to do when we knew only one thing — that all our previous plans had failed? I therefore called an all- day meeting of our senior program- mers on October 22, 1965, to thrash out the question among us. I still have the notes of that meeting. We first listed the recent major grievances of our customers: cancellation of prod- ucts, failure to meet deadlines, ex- cessive size of software "not justified by the usefulness of the facilities pro- vided," excessively slow programs, failure to take account of customer feedback. "Earlier attention paid to quite minor requests of our customers might have paid as great dividends of goodwill as the success of our most ambitious plans," we concluded. We then listed our own grievances: lack of machine time for program testing, unpredictability of machine time, lack of suitable peripheral equipment, unreliability of the hard- ware even when available, dispersion of programming staff, lack of equip- ment for keypunching of programs, lack of firm hardware delivery dates, lack of technical writing effort for documentation, lack of software knowledge outside the programming group, interference from higher managers who imposed decisions without a full realization of the more intricate implications of the matter, and overoptimism in the face of pressure from customers and the sales department. But we did not seek to excuse our failure by these grievances. For exam- ple, we admitted that it was the duty of programmers to educate their managers and other departments of the company by presenting the neces- sary information in a simple palatable form. The hope "that deficiencies in original program specifications could be made up by the skill of a technical writing department... was misguided. The design of a program and the design of its specification must be undertaken in parallel by the same person, and they must interact with each other. A lack of clarity in speci- fication is one of the surest signs of a deficiency in the program it describes, and the two faults must be removed simultaneously before the project is embarked upon." I wish I had fol- lowed this advice in 1963; I wish we all would follow it today. My notes of the proceedings of that day in October 1965 include a com- plete section devoted to failings within the software group; this sec- tion rivals the most abject self- abasement of a revisionist official in the Chinese cultural revolution. Our main failure was overambition. "The goals which we have attempted have obviously proved to be far beyond our grasp." There was also failure in prediction, in estimation of program size and speed, of effort required, in planning the coordination and in- teraction of programs, in providing an early warning that things were go- ing wrong. There were faults in our control of program changes, docu- mentation, liaison with other depart- ments, with our management, and with our customers. We failed in giv- ing clear and stable definitions of the responsibilities of individual pro- grammers and project leaders. Oh, need I go on? What was amazing was that a large team of highly intelligent programmers could labor so hard and so long on such an unpromising proj- ect. You know, you shouldn't trust us intelligent programmers. We can think up such good arguments for convincing ourselves and each other of the utterly absurd. Especially don't believe us when we promise to repeat an earlier success, only bigger and better next time. The last section of our inquiry into the failure dealt with the criteria of quality of software. "In the recent struggle to deliver any software at all, the first casualty has been considera- tion of the quality of the software delivered. The quality of software is measured by a number of totally in- compatible criteria, which must be carefully balanced in the design and implementation of every program." We then made a list of no less than seventeen criteria which has been published in a guest editorial in Volume 2 of the journal Software Practice and Experience. Recovery Period How did we recover from the catastrophe? First, we classified our 503 customers into groups, according to the nature and the size of the hard- 420 September 1981 © BYTE Publications Inc ware configurations which they had bought. For example, those with magnetic tapes were all in one group. We assigned to each group of custom- ers a small team of programmers and told the team leader to visit the customers to find out what they wanted, to select the easiest request to fulfill, and to make plans (but not promises) to implement it. In no case would we consider a request for a feature that would take more than three months to implement and de- liver. The project leader would then have to convince me that the customer's request was reasonable, that the design of the new feature was appropriate, and that the plans and schedules for implementation were realistic. Above all, I did not allow anything to be done which I did not myself understand. It worked I The software requested began to be delivered on the promised dates. With an increase in our confidence and that of our customers, we were able to undertake fulfilling slightly more ambitious requests. Within a year, we had recovered from the disaster. Within two years, we even had some moderately satisfied customers. Thus we muddled through by com- mon sense and compromise to some- thing aproaching success. But I was not satisfied. I did not see why the design and implementation of an op- erating system should be so much more difficult than that of a compiler. This is the reason why I have devoted my later research to problems of parallel programming and language constructs which would assist in clear structuring of operating systems — constructs such as monitors and com- municating processes. While I was working at Elliott, I became very interested in techniques for formal definition of programming languages. At that time, Peter Landin and Christopher Strachey proposed to define a programming language in a simple functional notation that specified the effect of each command on a mathematically defined abstract machine. I was not happy with this proposal because I felt that such a definition must incorporate a number of fairly arbitrary representation decisions and would not be much simpler in principle than an imple- mentation of the language for a real machine. As an alternative, I pro- posed that a programming language definition should be formalized as a set of axioms, describing the desired properties of programs written in the language. I felt that carefully formu- lated axioms would leave an imple- mentation the necessary freedom to implement the language efficiently on different machines and enable the programmer to prove the correctness of his programs. But I did not see how to actually do it. I thought that it would need lengthy research to develop and apply the necessary techniques, and that a university would be a better place to conduct such research than industry. So I applied for a chair in Computer Science at the Queen's University of Belfast, where I was to spend nine happy and productive years. In October 1968, as I unpacked my papers in my new home in Bel- fast, I came across an obscure reprint of an article by Bob Floyd entitled, "Assigning Meanings to Programs." What a stroke of luck! At last I could see a way to achieve my hopes for my research. Thus I wrote my first paper on the axiomatic approach to com- puter programming, published in the Communications of the ACM in October 1969. Just recently, I have discovered that an early advocate of the asser- tional method of program proving was none other than Alan Turing himself. On June 24, 1950, at a con- ference in Cambridge, he gave a short talk entitled, "Checking a Large Rou- tine," which explains the idea with great clarity. "How can one check a large routine in the sense of making sure that it's right?" Turing asked. "In order that the man who checks may not have too difficult a task, the pro- grammer should make a number of definite assertions which can be checked individually, and from which the correctness 'of the whole program easily follows." Consider the analogy of checking tipple computer Authorized Dealer FINDING SOLUTIONS summer AND BEING COMPETITIVE sale? 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. 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This principle can be applied to the checking of a large routine, but we will illustrate the method by means of a small routine: one to obtain n fac- torial without the use of a multiplier. Unfortunately, there is no coding system sufficiently generally known to justify giving this routine in full, but a flow diagram will be sufficient for illustration. That brings me back to the main theme of my talk, the design of programming languages. During the period August 1962 to October 1966, I attended every meeting of the IFIP ALGOL working group. After completing our labors on the IFIP ALGOL subset, we started on the design of ALGOL X, the intended successor to ALGOL 60. More suggestions for new features were made and in May 1965, Niklaus Wirth was commissioned to collate them into a single language design. I was delighted by his draft design, which avoided all the known defects of ALGOL 60 and included several new features, all of which could be simply and efficiently implemented, and safely and conveniently used. The description of the language was not yet complete. I worked hard on making suggestions for its im- provement, and so did many other members of our group. By the time of the next meeting in St. Pierre de Chartreuse, France, in October 1965, we had a draft of an excellent and realistic language design which was published in June 1966 as "A Con- tribution to the Development of ALGOL" in Communications of the ACM. It was implemented on the IBM 360 and given the title ALGOL W by its many happy users. It was not only a worthy successor of ALGOL 60, it was even a worthy predecessor of Pascal. At the same meeting, the ALGOL committee had placed before it a short, incomplete and rather incom- prehensible document describing a different, more ambitious and, to me, a far less attractive language. I was astonished when the working group, consisting of all the best known inter- national experts of programming lan- guages, resolved to lay aside the com- missioned draft on which we had all been working and swallow a line with such an unattractive bait. Two Design Paths This happened just one week after our inquest on the 503 Mark II soft- ware project. I gave desperate warn- ings against the obscurity, the com- plexity, and overambition of the new design, but my warnings went un- heeded. I conclude that there are two ways of constructing a software de- sign: One way is to make it so simple that there are obviously no deficien- cies, and the other way is to make it so complicated that there are no ob- vious deficiencies. The first method is far more dif- ficult. It demands the same skill, devotion, insight, and even inspira- tion as the discovery of the simple physical laws which underlie the complex phenomena of nature. It also requires a willingness to accept objec- tives which are limited by physical, logical, and technological con- straints, and to accept a compromise when conflicting objectives cannot be met. No committee will ever do this until it is too late. So it was with the ALGOL commit- tee. Clearly the draft which it pre- ferred was not yet perfect. So a new and final draft of the new ALGOL language design was promised in three months' time; it was to be sub- mitted to the scrutiny of a subgroup of four members including myself. Three months came and went, with- out a word of the new draft. After six months, the subgroup met in the Netherlands. We had before us a longer and thicker document, full of errors corrected at the last minute, describing yet another but to me, equally unattractive language. Niklaus Wirth and I spent some time trying to get removed some of the deficiencies in the design and in the description, but in vain. The com- pleted final draft of the language was promised for the next meeting of the full ALGOL committee in three months' time. Three months came and went — not a word of the new draft appeared. 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The experts in the group could not see the defects of the design and they firmly resolved to adopt the draft, believing it would be completed in three months. In vain, I told them it would not. In vain, I urged them to remove some of the technical mistakes of the language, the predominance of references, the default type conversions. Far from wishing to simplify the language, the working group actually asked the authors to include even more com- plex features like overloading of operators and concurrency. When any new language design project is nearing completion, there is always a mad rush to get new features added before standardization. The rush is mad indeed, because it leads into a trap from which there is no escape. A feature which is omitted can always be added later, when its design and its implications are well understood. A feature which is in- cluded before it is fully understood can never be removed later. At last, in December 1968, in a mood of black depression, I attended the meeting in Munich at which our long-gestated monster was to come to birth and receive the name ALGOL 68. By this time, a number of other members of the group had become disillusioned, but too late: the com- mittee was now packed with sup- porters of the language, which was sent up for promulgation by the higher committees of IFIP. The best we could do was to send with it a minority report, stating our con- sidered view that "...as a tool for the reliable creation of sophisticated pro- grams, the language is a failure." This report was later suppressed by IFIP, an act which reminds me of the lines of Hilaire Belloc: But scientists, who ought to know Assure us that it must be so. Oh, let us never, never doubt What nobody is sure about. I did not attend any further meetings of that working group. I am pleased to report that the group soon came to realize that there was some- thing wrong with their language and with its description; they labored hard for six more years to produce a revised description of the language. It is a great improvement but I'm afraid that, in my view, it does not remove the basic technical flaws in the design, nor does it begin to address the prob- lem of its overwhelming complexity. Programmers are always surround- ed by complexity; we cannot avoid it. Our applications are complex because we are ambitious to use our com- puters in ever more sophisticated ways. Programming is complex because of the large number of con- flicting objectives for each of our pro- gramming projects. If our basic tool, the language in which we design and code our programs, is also com- plicated, the language itself becomes part of the problem rather than part of its solution. Another Project Now let me tell you about yet another overambitious language project. Between 1965 and 1970 I was a member and even chairman of the Technical Committee No. 10 of the European Computer Manufacturers Association. We were charged first with a watching brief and then with the standardization of a language to end all languages, designed to meet the needs of all computer applica- tions, both commercial and scientific, by the greatest computer manufac- turer of all time. I had studied with interest and amazement, even a touch of amusement, the four initial docu- ments describing a language called NPL, which appeared between March 1 and November 30, 1964. Each was more ambitious and absurd than the last in its wishful speculations. Then the language began to be imple- mented and a new series of docu- ments began to appear at six -monthly intervals, each describing the final frozen version of the language, under its final frozen name PL/I. 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In the parts that had been im- plemented, the flowers had withered; they were choked by an undergrowth of explanatory footnotes, placing ar- bitrary and unpleasant restrictions on the use of each feature and loading upon a programmer the responsibility for controlling the complex and unex- pected side-effects and interaction ef- fects with all the other features of the language. At last, March 11, 1968, the lan- guage description was nobly pre- sented to the waiting world as a worthy candidate for standardiza- tion. But it was not. It had already undergone some seven thousand cor- rections and modifications at the hand of its original designers. Another twelve editions were needed before it was finally published as a standard in 1976. I fear that this was not because everybody concerned was satisfied with its design, but because they were thoroughly bored and disillusioned. For as long as I was involved in this project, I urged that the language be simplified, if necessary by subsetting, so that the professional programmer would be able to understand it and be able to take responsibility for the cor- rectness and cost-effectiveness of his programs. I urged that the dangerous features such as defaults and on con- ditions be removed. I knew that it would be impossible to write a wholly reliable compiler for a lan- guage of this complexity, and impos- sible to write a wholly reliable pro- gram when the correctness of each part of the program depends on checking that every other part of the program has avoided all the traps and pitfalls of the language. At first I hoped that such a tech- nically unsound project would col- lapse, but I soon realized it was doomed to success. Almost anything in software can be implemented, sold, and even used given enough determi- nation. There is nothing a mere scien- tist can say that will stand against the flood of a hundred million dollars. But there is one quality that cannot be purchased in this way — and that is reliability. The price of reliability is the pursuit of the utmost simplicity. It is a price which the very rich find most hard to pay. All this happened a long time ago. Can it be regarded as relevant in a conference dedicated to a preview of the Computer Age that lies ahead? It is my gravest fear that it can. The There is nothing a mere scientist can say that will stand against the flood of a hundred million dollars. mistakes which have made in the last twenty years are being repeated to- day on an even grander scale. I refer to a language design project which has generated documents entitled strawman, woodenman, tinman, ironman, steelman, green and finally now Ada. This project has been ini- tiated and sponsored by one of the world's most powerful organizations, the United States Department of De- fense. Thus it is ensured of an in- fluence and attention quite indepen- dent of its technical merits, and its faults and deficiencies threaten us with far greater dangers. For none of the evidence we have so far can in- spire confidence that this language has avoided any of the problems that have afflicted other complex language projects of the past. I have been giving the best of my advice to this project since 1975. At first I was extremely hopeful. The original objectives of the language in- cluded reliability, readability of pro- grams, formality of language defini- tion, and even simplicity. Gradually these objectives have been sacrificed in favor of power, supposedly achieved by a plethora of features and notational conventions, many of them unnecessary and some of them, like exceptions handling, even dangerous. We relive the history of the design of the motor car. Gadgets and glitter prevail over fundamental concerns of safety and economy. It is not too latel I believe that by careful pruning of the Ada language, it is still possible to select a very powerful subset that would be reliable and efficient in implementa- tion and safe and economic in use. The sponsors of the language have declared unequivocally, however, that there shall be no subsets. This is the strangest paradox of the whole strange project. If you want a lan- guage with no subsets, you must make it small. You include only those features which you know to be needed for every single application of the lan- guage and which you know to be ap- propriate for every single hardware configuration on which the language is implemented. Then extensions can be specially designed where necessary for particular hardware devices and for particular applications. That is the great strength of Pascal, that there are so few unnecessary features and almost no need for subsets. That is why the language is strong enough to support specialized extensions — con- current Pascal for real-time work, Pascal Plus for discrete event simula- tion, UCSD Pascal for micropro- cessor work stations. If only we could learn the right lessons from the suc- cesses of the past, we would not need to learn from our failures. And so, the best of my advice to the originators and designers of Ada has been ignored. In this last resort, I appeal to you, representatives of the programming profession in the United States, and citizens concerned with the welfare and safety of your own country and of mankind: do not allow this language in its present state to be used in applications where reliability is critical, ie, nuclear power stations, cruise missiles, early warn- ing systems, anti-ballistic missile defense systems. The next rocket to go astray as a result of a program- ming language error may not be an exploratory space rocket on a harmless trip to Venus. It may be a nuclear warhead exploding over one of our own cities. An unreliable programming language generating unreliable programs constitutes a far greater risk to our environment and to our society than unsafe cars, toxic 424 September 1981 © BYTE Publicalions Inc pesticides, or accidents at nuclear power stations. Be vigilant to reduce that risk, not to increase it. Let me not end on this somber note. To have our best advice ignored is the common fate of all who take on the role of consultant, ever since Cassandra pointed out the dangers of bringing a wooden horse within the walls of Troy. That reminds me of a story I used to hear in my childhood. The Emperor's Old Clothes Many years ago, there was an Emperor who was so excessively fond of clothes that he spent all his money on dress. He did not trouble himself with soldiers, attend banquets, or give judgment in court. Of any other king or emperor one might say, "He is sitting in council," but it was always said of him, "The emperor is sitting in his wardrobe." And so he was. On one unfortunate occasion, he had been tricked into going forth naked to his chagrin and the glee of his sub- jects. He resolved never to leave his throne, and to avoid nakedness, he ordered that each of his many new suits of clothes should be simply draped on top of the old. Time passed away merrily in the large town that was his capital. Ministers and courtiers, weavers and tailors, visitors and subjects, seamstresses and embroiderers, went in and out of the throne room about their various tasks, and they all ex- claimed, "How magnificent is the at- tire of our Emperor." One day the Emperor's oldest and most faithful minister heard tell of a most distinguished tailor who taught at an ancient institute of higher stitch- craft, and who had developed a new art of abstract embroidery using stitches so refined that no one could tell whether they were actually there at all. "These must indeed be splendid stitches," thought the minister. "If we can but engage this tailor to advise us, we will bring the adornment of our Emperor to such heights of osten- tation that all the world will acknowledge him as the greatest Emperor there has ever been." So the honest old minister engaged the master tailor at vast expense. The tailor was brought to the throne room, where he made obeisance to the heap of fine clothes which now completely covered the throne. All the courtiers waited eagerly for his advice. Imagine their astonishment when his advice was not to add sophistication and more intricate em- broidery to that which already ex- isted, but rather to remove layers of the finery, and strive for simplicity and elegance in place of extravagant elaboration. "This tailor is not the expert that he claims," they muttered. "His wits have been addled by long contempla- tion in his ivory tower, and he no longer understands the sartorial needs of a modern Emperor." The tailor argued loud and long for the good sense of his advice but could not make himself heard. Finally, he ac- cepted his fee and returned to his ivory tower. Never to this day has the full truth of this story been told: that one fine morning, when the Emperor felt hot and bored, he extricated himself care- fully from under his mountain of clothes and is now living happily as a swineherd in another story. The tailor is canonized as the patron saint of all consultants, because in spite of the enormous fees that he extracted, he was never able to convince his clients of his dawning realization that their clothes have no Emperor. ■ BYTE's Bits Transplanted Apple Shoppe Joesph L Rollinson is the new publisher of The Apple Shoppe Magazine. Apple Shoppe, which describes itself as the "journal of Apple applications," is a periodical for users of Apple II and III computers. The magazine was previously published by David Smith of Placentia, California. Mr Rollinson is a native of San Diego, California. Apple Shoppe is published eight times a year, for a subscriber's cost of $12 in the United States. Contact The Apple Shoppe Magazine, POB 22026, San Diego CA 92122. ■ Circle 172 on inquiry card. 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Wilmington Avenue, Suite 306 Carson, CA 90745 • Call (213) 518-4245 September 1981 © BYTE Publications Inc 425 Technical Forum Microcomputers and the IRS James C Kingman, Chief, Examination Section Helena International Revenue Service District Helena MT 59601 Although the author is an employee of the Internal Revenue Service, the content of this article is his opinion and does not necessarily reflect the position of the United States Internal Revenue Service. ...SM The 1980s will see unprecedented growth in the use of microcomputers by small independent businesses and professional persons. With great potential for fast, ac- curate processing of accounting data and other types of business records at a minimal cost, microcomputers, like photocopying machines, will soon be standard equip- ment in most offices. Microcomputers offer a means of simplifying record- keeping systems while producing more timely, accurate, and detailed reports than were ever possible using a manual accounting system. The greatest benefit to a small business or professional person, however, is the cost. For a cost comparable to the annual salary of a bookkeeper, the individual can purchase a hardware and software system capable of many times the work output of a single person. If the system is well planned and prop- erly implemented, it can result in an overall cost savings and a significant increase in the usefulness and efficiency of the record-keeping system. Traditionally, a person entering a new business works with his accountant to set up a record-keeping system that meets generally accepted accounting principles and practices. These systems provide a logical method of trac- ing detailed records such as invoices and vouchers through the accounting process to the final financial reports. The systems usually produce a general ledger which is supported by subsidiary ledgers or such journals as Accounts Receivable and Accounts Payable. These, in turn, provide a complete listing of the detailed records. Thus, with the traditional method it is possible to trace an individual detailed record through the entire system. This system of tracking records is known as the 'Audit Trail." As more and more business and professional people ac- quire and learn to program their microcomputer systems, there may be a temptation to simplify record-keeping sys- tems to the point where the Audit Trail is lost. For exam- ple, an individual might be tempted to write a program that would simply require the input of detailed records and would produce completed financial statements as output. While such a program would be very simple to write and even simpler to operate, it would completely eliminate any form of Audit Trail. The lack of an Audit Trail creates two major problems: First, any error or discrepancy on the original detailed record would be impossible to locate without a complete reconstruction of all detailed records. Suppose you had such a simplified program for your Accounts Receivable. Each day, week, or month you would key in new charges and payments on account. At the end of the period your simple system would produce a statement for each cus- tomer, without any reference to the original detailed records. Such a program might work well as long as no errors were made in entering the detailed records. What would happen, however, if one of your customers paid $50 on his account and you recorded $5? Without a refer- ence to any records, you would need to manually recon- struct the customer's entire account to verify whether or not he had, in fact, paid $50. Not only would the process be time-consuming — it would create a relation problem with the customer because of the original error. The second problem with such a program is that it is unacceptable to the Internal Revenue Service. Section 6001 of the Internal Revenue Code of 1954 requires, in part, that "every person liable for any tax imposed by this title, or for the collection thereof, shall keep such records, render such statements, make such returns and comply with such rules and regulations as the Secretary may from time to time prescribe." Under the authority of this code section, the Internal Revenue Service has issued Revenue Procedure 64-12 (Cumulative Bulletin 1964-1, Part 1, page 672), which defines "guidelines for record re- quirements to be followed in cases where part or all of the account records are maintained within automatic data processing systems." The Internal Revenue Service has also issued Revenue Ruling 71-20 (Cumulative Bulletin 1971-1, page 392), which holds that "punched cards, magnetic tapes, disks, and other machine-sensible data media used in the automatic data processing of account- ing transactions constitute records within the meaning of section 1.6001-1 of the regulations." Let us see how this Revenue Procedure and Revenue Ruling affect the busi- 426 September 1981 © BYTE Publications Inc ness or professional person using a microcomputer in his business. Revenue Procedure 64-12 deals directly with the need for an Audit Trail in an accounting system. Section 1.01 of the Revenue Procedure states its purpose: Section 1. Purpose .01 The purpose of this Revenue Procedure is to set forth guidelines specifying the basic record re- quirements which the Internal Revenue Service considers to be essential in cases where a taxpayer's records are maintained within an auto- matic data processing (ADP) system. References here to ADP systems include all accounting sys- tems which process all or part of a taxpayer's transactions, records, or data by other than manual methods. Section 3 states the objectives of the Revenue Pro- cedures: Section 3. Objectives .... The ability to provide in legible form the data necessary to determine at a later date whether or not the correct tax liability has been reported must be carefully considered in designing and program- ming a machine system. This factor may add to the complexity of the system and require addi- t ional cost, but this cost may be negligible in com- parison to the expense that may be incurred at a l ater date if the system cannot practically and readily provide the information needed to suppor t and substantiate the accuracy of the previously reported tax liability . (Emphasis supplied.) Section 4 gives the specific record requirements that the Internal Revenue Service considers essential in any ADP accounting system: Section 4. ADP Record Guidelines .01 ...A computer's accounting program must include a method of producing from the punched cards or tapes visible and legible records which will pro- vide the necessary information for the verification of the taxpayer's tax liability. .02 General and Subsidiary Books of Account. — A (1) general ledger, with source references, should be written out to coincide with financial reports for tax reporting periods. In cases where subsidiary ledgers are used to support the general ledger ac- counts, the subsidiary ledgers should also be writ- ten out periodically. (2) Supporting Documents and Audit Trail. — The audit trail should be designed so that the details underlying the summary accounting data, such as invoices and vouchers, may be identified and made available to the Internal Revenue Service upon request. (3) Recorded or Reconstructible Data. — The records must provide the opportunity to trace any trans- action back to the original source or forward to a final total. If printouts are not made of transac- tions at the time they are processed, then the system must have the ability to reconstruct these transactions. Revenue Ruling 71-20 clarifies the term "records" as used in Code Section 6001: ...At is held that punched cards, magnetic tapes, disks, and other machine-sensible data media used for recording, consolidating, and summarizing ac- counting transactions and records within a tax- payer's automatic data processing system are records within the meaning of section 6001 of the Code and section 1.6001-1 of the regulations and are required to be retained so long as the contents may become material in the administration of any internal revenue law... Both the Revenue Procedure and the Revenue Ruling are well known to most large companies using computer systems in their accounting process, but they may not be as well known to the small business using mini- and microcomputer systems. These businesses should check the following items in order to be sure their systems meet the requirements of the Internal Revenue Service: • Any system or program should preserve the in- tegrity of the Audit Trail so that any summary total may be traced back to the original detailed records, and any detailed record may be traced forward to the summary total. • If the system or program does not produce print- outs of the detailed transactions as they are pro- cessed, then the system or program must have the ability to reconstruct these transactions at the re- quest of the Internal Revenue Service. • If the system or program maintains accounting records on machine-sensible data media, such media are considered records and must be main- tained for the same period of time as a hard-copy printout. • Finally, if the system or program does maintain such machine-sensible data media, the system or program must include a method of producing visi- ble and legible printouts of the media. This article may raise more questions than it has answered. What should you do if you have questions about your system? A final quote from Revenue Ruling 71-20: ...taxpayers who are in doubt as to which records are to be retained or who desire further informa- tion should contact their District Director for assistance. ■ September 1981 © BYTE Publications Inc 427 Technical Forum Add Dual Trace and Delayed Sweep to Your Oscilloscope Robert J Stetson, BASF Systems Crosby Dr, Bedford MA 01730 Occasionally the need arises to make timing com- parisons between two signals with an interval delay. However, with a conventional oscilloscope you cannot scan a looped serial-data exchange with the clock in registration and still look at the data that occurs 40 bytes later. In this situation, you may want to build an add-on unit that converts your present single-channel scope to a digital dual-trace scope with delayed sweep for about $15. Theory of Operation — Data Multiplexer Figures 1 and 2 show the complete logic diagram of the unit. Figure 2 is a simple, stable, clock circuit. A chop- ping frequency of 1 F CLK was selected, since it is com- mon among dual-trace scopes. The 555 integrated circuit is used as a free-running timer that generates 2 F CLK. Since the output of the 555 is highly asymmetrical, it runs at twice the desired rate, and 2 F CLK is fed to the input of a 74LS74-type D edge flip-flop. The 74LS74 is wired as a divider and neatly converts the pulse train from the 555 timer into a perfectly symmetrical square wave of half the frequency of 2 F CLK. It is important that 1 F CLK be symmetrical to insure that the two traces have the same relative brightness. This brightness is a direct function of the sample time (controlled by 1 F CLK) for each channel. In figure 1, 1 F CLK enables the channel 1 NAND gate (74LS00) when high, and enables the channel 2 NAND gate (74LS00) through a 74LS04 inverter when low. The two channels are multiplexed into a single signal on pin 11 of the 74LS00, an active low NOR gate. Vertical separation of the traces can best be understood by walking through the circuit with 0V input to both channels. If both inputs stay at a low level, the output on pin 11 of the 74LS00 NOR gate stays low. Even though there is no signal, the output signal, SCOPE, will switch at 1 F CLK speed. The diagrams in figure 4 show the relationship between the 100 k-ohm 1 F CLK leg of the summing network and the 150 k-ohm DATA leg. With 1 F CLK in a low logic state, the DATA input selects one of the two possible zones in the channel 2 area of the screen. With 1 F CLK high, the DATA input selects one of the two channel 1 areas of the screen: Where DATA is low, DATA = V Where 1 F CLK is low, 1 F CLK = V Where DATA is high, DATA - 2 V Where 1 F CLK is high, 1 F CLK « 3 V The output from the summing network is one of the four possible combinations: low + low = channel 2 low + = V low + high = channel 2 high + 1 = 2 V high + low = channel 1 low 1 + = 3 V high + high = channel 1 high 1 + 1 = 5 V Even though half of the oscilloscope display time is spent on the upper area of the screen and half on the lower, the traces appear as two solid lines, because the 1 F CLK is synchronized with the two channel inputs, but not with the scope. The chopping frequency free-runs with relationship to the horizontal-sweep frequency of the scope, which is synchronized only with the signal at the input to channel 1. Any attempt to synchronize on the signal at the multi- plexer's SCOPE output will fail. The multiplexing action only allows you to synchronize on 1 F CLK; otherwise, as the two channels of data race across the screen they will be out of synchronization with the horizontal oscillator in the scope. A sample of the signal on which you want to synchronize is taken from the channel 1 input before it gets chopped by the multiplexer. This signal is then coupled by the trigger-control circuit to the scope's SYNC or TRIGGER input. Trigger Control Circuit Theory When INT (internal trigger) is used, the channel 1 probe should always be on the signal from which you want to synchronize. The 74LS04 inverter at the channel 1 input buffers the input signal so that the circuit being sampled does not see the added load of the extra cir- cuitry. The second 74LS04 reinverts the signal to its true polarity. Inverters are placed in the channel 2 signal path to balance the gate delays between the two channels. This ensures accurate results, regardless of the quality of the scope. Another 74LS04 inverter gates the signal over to a switch where either NORMAL trigger mode or DELAYED SWEEP is selected. With the MODE switch in the NORM position, the 428 September 1981 © BYTE Publications Inc sv A f RANGE X ,0.01/iF ^-TNO.l/iF ;i/tF VERNIER 10K POT I ,_ I EXT I ^"^ i & _ l SLOPE 10 ■IK ;o.l^F C R/C B 74LS121 Al Q Jm 390pF 10 £ ITI lOOO^F 11 B Q 74LS121 Al MODE -*T -Ogo EXT VINT, 1 " ^ i SOURCE I I 1 NORM o^ CHANNEL 1 (Or [>. DELAY I I LS7404 - a ^O ■ 1 \ 8 13 ' . 12 y^ a c > I^n LS7404 I I ^ KT CHANNEL 2 (07 11 LS7404 LS7400 LS7404 H \_ 6 9 8 13 d J 3 — 1 5 b p d >° — H / ! -* • l^ LS7400 <, JfZ^ . LS7404 DATALEg4 1. v " © - N 3 IF CLOCK LEG-* T L _°y |iook 50K DATA LEG*! SC0PE LS7400 -o IF CLOCK Figure 1: Multiplex interface schematic for adding dual trace and delayed sweep to an oscilloscope. See text for details on how the circuit works. trigger signal is switched straight through to the 74LS04 inverter, which drives the 2N2222 transistor output- driver. The TRIGG output is monitored by the coupling capacitor, which sets off the trigger timer and lights the trigger LED (light-emitting diode). The 74LS74 driving the trigger LED acts as an inverter: with its_preset and clear inputs both low, the output on Q and Q are high. But, when the clear input goes high, the output Q goes low. In this way, the Q output will always be the inverse of the clear input, while the Q output remains high at all times. As long as the trigger LED remains lit, the scope is being triggered. With the MODE in the DELAY position, the trigger pulses are routed through the SLOPE switch. The SLOPE switch directs the pulse to either the A or B input of a 74L121 monostable multivibrator. I chose a 74L121 over other multivibrators because it is not retriggerable. While a 74LS123 would reduce the parts count, recurring triggers would extend the delay time indefinitely. By using the RANGE and VERNIER controls, you can adjust the delay time. These controls increase or decrease the time from the selected edge of the triggering pulse to the timeout of the first stage of the timer chain. The sec- ond 74L121 fires when the first one times out. The second emits a short spike from which to trigger the scope. An additional feature, the SOURCE switch, allows you to trigger from an independent source. This may be an in- dex pulse, sector pulses or other reference signals from equipment you are working on. Mastering the use of this unit requires patience. For in- stance, the channel 1 trigger source can be used only in certain applications. Other applications are best served by the external trigger option. Under certain conditions during the delayed-sweep mode, a vertical line appears on the left edge of the screen, caused by the deflection of the beam in the absence of a horizontal trace. Since this add-on unit can only be used on logic-level signals, the unit under test can supply power. No internal power supply is shown, but you may prefer to add one. The true amplitude of the signals on the SCOPE output will be less than the 2 V, 3 V, and 5 V levels in the description given here, because the output of the TTL devices during their source mode are less than the supply voltage. Also, the resulting voltage will be further reduced by the input impedance of the scope. Caution: If you're tempted to cut up the front panel of September 1981 © BYTE Publications Inc 429 Technical Forum, + 5V A GO O- 1K -WV- 2N2222 12K -VW- 8 ,005/iF C TSD 555 CV OCG GND Q O.Ol^F /77 50K ^47/tF /77 IN914 2N2222 TRIG :i5on TRIGGER LED • 10K -wv TRIMMER O.Ol^iF 8 TRIMMER 10K -Wv V cc DCG C TSG 555 CV T GND Q 1 3 . 0.05>iF m D Q LS7474b T Q -O IF CLK I |« »| 10/xS /77 Figure 2: Clock and trigger circuit. ■(I) A - SCOPE (5 VOLTS) CHANNEL 2 IN HIGH ZONE CHANNEL 1 IN HIGH ZONE Figure 4: Operation of the circuit shown in figures 1 and 2. Each of the four input conditions decodes to four different zones on the oscilloscope screen. COMPSTfiT TH6 MOST COMPRC-HC-NSIV6 STATISTICS PACKAG6 AVAILABLE FOR MICROCOM- PUT6RS. NORTH STAR BASIC AND 8" BAZIC* V6RSIONS AVAILABLE. OVC-R 420 PROGRAMS COV6RING ANALVSIS OF VARIANCE, BASIC STATS, CONTINGCNCY TABIC- T6CHNIOUC-S, €STIMATION, CXPLORA- TORY DATA ANALVSIS, FOURI€R ANALVSIS, NONPARAM6TRIC STATISTICS, MULTIVARIAT6 STATISTICS, PROBABILITY PLOTTING, QUALITY CONTROL, RANDOM VARIATC G6N6RATION, RC-GRC-SSION, ROBUST TCCHNIQUCS, SAM- PLING, STATISTICAL DISTRIBUTIONS, SURVIVAL TCCHNIQU6S AND TIMC SCRICS. COMPLCTC- PACKAGC MANUAL ONLY $1500 $100 TOPICS SOLD SCPARRT6LY AT $200 A TOPIC. COMPSTfiT P.O. BOX 268 GLOUC€ST€R POINT, Vfl. 23062 •SRZIC IS R R6GISTeR6D TRflDgMflRK OF MICRO MIKE'S. V * — "^ tAno\ a r?»§is*^ (4Uo) 4^0-04 1 1 - — ^~-^/ QUME DT 8 s 545 Includes 1 year factory warranty TELETEK FDC 1 • 4 MHZ CPU • NEC 765 FDC s 605 1 YEAR WARRANTY QUME DT 5 s 315 QUME SPRINT 9/45 s 2295 LIGHT PEN WITH CORD & SOCKET $75 INTERLINK MODEM • 300-600 BAUD • ASYN/SYN • AUTO DIAL • AUTO ANSWER • SERIAL AND MODULAR JACK INTERFACE • 2 YEAR WARRANTY s 119 FLOPPY DISK ADD-ONS • DUAL-DOUBLE DENSITY DRIVES • ENCLOSURE • POWER SUPPLY • FAN • ALL CABLES • 1 YEAR WARRANTY 8" SYSTEM s 1375 5 1 /4" SYSTEM s 949 Circle 66 on inquiry card. Circle 285 on inquiry card. September 19B1 © BYTE Publications Inc 431 System Notes An Almost Optimum Z80 Memory Test Program Ira J Rampil, 60 Haven Ave Apt 15D, New York NY 10032 One of the great joys of building a computer is testing to see whether or not it works. The most interesting sub- system to check is the memory. Even average-sized memory systems contain several hundred thousand bits, each of which must be checked to insure that it can store and output the desired data. The memory must also be tested to confirm both the uniqueness of the address and the absence of bit-to-bit interference. Problems such as printed-circuit-board shorts and decoder-circuit bugs can cause data access at one address to disturb data at an en- tirely different address. Decoder-circuit bugs are usually encountered when a new memory is first brought up, but printed-circuit-short problems can and do occur at any time. Most memory component failures also occur early. It is not feasible to detect and localize any but the most severe problems through the use of manual hardware debugging techniques. Memory bugs are best found by using software techniques, provided that plugging the questionable boards into the system bus doesn't cause the whole system to crash. As long as the processor, some peripherals, and at least some memory are up, programs can be loaded and run to test the remaining memory. The most obvious test is to store all possible combina- tions of bits. Unfortunately there are 2 262144 possible com- binations in a 32 K- by 8-bit memory. To test each possi- ble combination separately would take a length of time significantly greater than the projected duration of the universe. A great deal of research has been done in order to find tricks that will shorten the time required to test memory, but many manufacturers and suppliers of microcomputer kits seem unaware of the results. For example, I recently built a system kit that was supplied with a memory test program that counted from to hexadecimal FF, check- ing each increment in every byte in memory. It took more than five minutes per pass in my 34 K memory, and the program failed to detect four address-line foil bridges, one solder splash, and the bad decoder chip that mapped two 8 K boards into the same memory location. It did locate a data-to-address foil short and a few bad memory chips, but the program crashed after every bug it caught. By contrast, the program I'm about to describe can detect all of these problems and most others, except certain bit- to-bit interference problems, within a single byte. It runs on the same system in less than 3 seconds per pass. Memory problems usually occur as input (address) or output (data) lines that are stuck at either a or a 1, or a line having the value of a different line. Such problems are the result of open circuits or shorts to power lines. Blown memory devices usually have bits that are inter- nally shorted or open. It should be understood that memory test programs will detect these problems and usually supply the offending addresses, but will almost never diagnose the problem. Diagnosis remains a human function that uses clues provided by memory test and dump routines. After localizing a bug, successive dumps of the offending area of memory while changing data at that address will reveal patterns characteristic of the par- ticular bug. The program described here is based on an algorithm described by John Knaizuk and C R P Hartmann (IEEE Transactions on Computers, April 1977). This algorithm is called optimal because it uses the minimal number of memory accesses to test the memory for all single-bit er- rors. It also catches many multiple-bit errors. The memory under test is divided into three partitions based upon the byte addresses modulo 3. When a parti- tion is accessed, all memory addresses within it are ac- cessed. Each partition is then independently accessed. The address lines and the decoding circuits are ex- haustively tested. Data lines and memory chips are also tested, to the extent that each bit must be able to write and read back both a and a 1. The algorithm uses a total of four accesses per address. This corresponds to the number of accesses required to read and write a and a 1 in each location. The program shown in listing 1 was written for a Digital Group Z80 system, but it can be easily trans- ported to other Z80 and 8080 systems. The major changes will be in the character output linkages and system utilities. I do not claim that this code is optimally short or fast. It was written to be legible, and it is fast enough and reasonably short. If an error is encountered, the offend- ing address is printed, along with the erroneous data byte read and the correct byte. Errors do not terminate the test and an "A" is printed at the completion of the test se- quence. ■ 432 September 1981 © BYTE Publications lnc Listing 1: A memory test program for the Z80 microprocessor. Although written for a Digital Group Z80 system, it can easily be modified for 8080 and other Z80 systems. Note the use of octal notation. ASSM 006000 100000 006000 0100 006000 0110 006000 0120 006000 0130 006000 0140 006000 0150 006000 0160 006000 315 346 0000 0170 006003 0175 006003 0180 006003 0185 006003 315 251 006 0190 006006 0200 006006 0210 006006 0220 006006 021 001 000 0230 006011 315 117 006 0240 006014 021 002 000 0250 006017 315 117 006 0260 006022 021 000 377 0270 006025 315 117 006 0280 006030 021 001 000 0290 006033 315 147 006 0300 006036 021 001 377 0310 006041 315 117 006 0320 006044 021 002 000 0330 006047 315 147 006 0340 006052 021 000 377 0350 006055 315 147 006 0360 006060 021 001 377 0370 006063 315 147 006 0380 006066 021 000 000 0390 006071 315 117 006 0400 006074 315 147 006 0410 006077 021 002 377 0420 006102 315 117 006 0430 006105 315 147 006 0440 006110 076 201 0450 006112 315 372 000 0460 006115 030 264 0470 006117 0480 006117 0490 006117 0500 006117 052 255 006 0510 006122 173 0520 006123 205 0530 006124 157 0540 006125 174 0550 006126 316 000 0560 006130 147 0570 006131 162 0580 006132 043 0590 006133 043 0600 006134 043 0610 006135 170 0620 006136 274 0630 006137 330 0640 006140 040 367 0650 006142 171 0660 006143 275 0670 006144 330 0680 006145 030 362 0690 006147 0700 006147 0710 006147 0720 006147 052 255 006 0730 006152 173 0740 006153 205 0750 006154 157 0760 006155 174 0770 006156 316 000 0780 * AN ALMOST PERFECT MEMORY * TESTER BASED ON THE K-H * ALGORITHM. WRITTEN BY " IRA IAY RAMPIL FOR * THE Z-80 ********************************** BEGIN CALL ERASE * FIND TOP OF MEMORY MAIN CALL TOP " TEST SEQUENCE ;CLEAR SCREEN WR WLP RD LD DE, 000001 CALL WR LD DE, 000002 CALL WR LD DE, 377000 CALL WR LD DE, 000001 CALL RD LD DE, 377001 CALL WR LD DE, 000002 CALL RD LD DE, 377000 CALL RD LD DE, 377001 CALL RD LD DE, 000000 CALL WR CALL RD LD DE, 377002 CALL WR CALL RD LD A, 301 CALL TV IR MAIN CUTIN 2 TO WRITE 1 LD HL,(START) LD A,E ADD L LD L,A LD A,H ADC LD H,A LD (HL),D INC HL INC HL INC HL LD A,B CP H RET C JR NZ.WLP LD A,C CP L RET C JR WLP DUTIN E TO READ A LD HL.(START) LD A,E ADD L LD L,A LD A,H ADC SIGNAL END OF TEST TO SCREEN START OVER SETUP STARTING ADDR OF PARTITION WRITE LOOP TO FILL PARTITION Listing 1 continued on page 434 September 1981 © BYTE Publications Ire 433 System Notes. Listing 1 continued: 006160 147 0790 006161 176 0800 006162 272 0810 006163 304 203 006 0820 006166 043 0830 006167 043 0840 006170 043 0850 006171 170 0860 006172 274 0870 006173 330 0880 006174 040 363 0890 006176 171 0900 006177 275 0910 006200 330 0920 006201 030 356 0930 006203 0940 006203 0950 006203 0960 006203 325 0970 006204 134 0980 006205 315 267 001 0990 006210 135 1000 00621 1 315 267 001 1010 006214 076 275 1020 006216 315 372 000 1030 006221 136 1040 006222 315 267 001 1050 006225 076 233 1060 006227 315 372 000 1070 006232 132 1080 006233 315 267 001 1090 006236 305 1100 006237 006 022 1110 006241 315 370 000 1120 006244 020 373 1130 006246 301 1140 006247 321 1150 006250 311 1160 006251 001 377 207 1170 006254 311 1180 006255 1190 006255 1200 006255 1210 006255 1220 006255 1230 006255 1240 006255 1250 006255 1260 006255 1270 006255 1280 006255 1290 006255 1300 006255 1310 006255 1320 006255 1330 006255 1340 006255 270 006 1350 RLP ERR SPACE TOP LD H,A LD A,(HL) CP D CALL NZ.ERR INC HL INC HL INC HL LD A,B CP H RET C JR NZ.RLP LD A,C CP L RET C JR RLP DUTIN1 I TO PRINT PUSH DE LD E,H CALL OCT LD E,L CALL OCT LD A, 275 CALL TV LD E,(HL) CALL OCT LD A, 233 CALL TV LD E,D CALL OCT PUSH BC LD B,22 CALL TV-2 DJNZ SPACE POP BC POP DE RET LD BC, 207377 RET ;FOUND A BUG ;PUT OFFENDING ADDRESS ON TV .-OUTPUT " = " ;OUTPUT OFFENDING CONTENTS ON TV ;OUTPUT DESIRED CONTENTS ;OUTPUT SPACES TO GET NEXT ;LINE OF TV SCREEN ;MY SYSTEM'S TOP OF MEMORY * TV IS A ROUTINE THAT OUTPUTS * THE CONTENTS(CHARACTER) OF A TV EQU 372 * OCT IS A ROUTINE THAT CONVERTS THE * CONTENTS OF E FROM BINARY TO OCTAL * AND THEN PRINTS IT ON TV OCT EQU 001267 * ERASE IS A ROUTINE THAT ERASES * THE SCREEN ERASE EQU 346 START DW 006270 434 September 1981 © BYTE Publications Inc Technical Forum How to Build an Inexpensive Cassette Level Indicator Dr Milan D Chepko 119 Belleville Ct Thief River Falls MN 56701 Looking for an inexpensive way to adjust the level of your recorder when loading programs into your microcomputer? The circuit diagram in figure 1 shows two LEDs (light-emitting diodes) and a 270- to 330-ohm resistor wired across the line from the recorder's ear- phone jack. The earphone or speaker is optional, but it allows you to hear the data transfer in operation. A photograph of the completed circuit is shown in photo 1. Most microcomputers require about two volts of audio signal for reliable operation. Since LEDs "turn on" at about 1.7 V, adjust the recorder's volume control until one of the LEDs begins to flicker steadily, and you should be in business. The LEDs also seem to absorb some of the extra signal if you turn the volume up too high.B 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. Photo 1: The cassette level indicator built inside a small plastic box. output to [|v- COMPUTER tl MINIATURE PHONE JACK ' 330il % I x- SMALL SPEAKER OR EARPHONE f TIL-209A TYPICAL FOR 2 -B TO EARPHONE JACK J^ ON RECORDER MINIATURE PHONE PLUG Figure 1: Schematic diagram of the cassette level indicator. September 1981 © BYTE Publications Ire 435 Software Review Interactive Fiction: Six Micro Stories Bob Liddil, The Programmer's Guild, POB 66, Peterborough NH 03458 Adventure International has a new concept in com- puter simulation called Interactive Fiction. The product I'm reviewing is a sampler of six Interactive Fiction stories. The sampler is, of course, designed to whet your curiosity about the full-length titles offered by the com- pany. Defined in its simplest terms, an Interactive Fiction epi- sode is a story that needs your responses to achieve its outcome. It goes far beyond Adventure's two-word re- sponses by encouraging you to input complete sentences. I must confess that, at first, I was uncomfortable with the new format. Gradually, though, I became accustomed to bantering with the computer. The first story places you in wartime Nazi Germany. You're an Allied spy, and you must uncover as many se- crets as possible. You have been invited to a banquet, where you find yourself chatting with a high-ranking Gestapo officer. The conversation between you and the computer determines whether you live or die. In another scenario, you are a near-bankrupt shipping tycoon entertaining a Greek billionaire. He has just made a $30 million offer for your company, but you know that in a day or so your company will be worth only $10 mil- lion. I took great delight in fleecing that fellow for $70 million. Interactive Fiction seems to be a stylized Eliza or Dr Chips, both of which are programs that cause the com- puter to act as if it understands your input. While giving the illusion of intelligence, these scenarios actually have a smaller vocabulary than the most basic Adventures. For example, there's a story about a chance encounter in San Francisco. You're in a park and you stumble upon a pret- ty girl who has dropped her books. Her monosyllabic replies not only break the mood of the story, but sadly at- test to the lack of intelligence in the program. Don't mis- understand me; these stories do have some redeeming qualities. As in Eliza, the computer "psychiatrist," it is obvious that the program zeros in on individual words, ignoring most of the input. The rest of the stories in the sampler are similarly disappointing in their lack of versatility; there are only a couple of ways each story can be played. I suspect that Six Micro Stories is not an adequate showcase of the Interactive Fiction concept. The stories fall far short of what the computer community expects from Scott Adams. As a party mixer or novelty, this of- fering will fill the bill, but don't buy this package expect- ing the high-quality entertainment you've received from Adventure International in the past. Six Micro Stories should be approached as a sampler. If you expect more, you are inviting disappointment. If you want to get into the heart of this new format, you had better get Local Call for Death or Two Heads of the Coin, two full-length titles in the Interactive Fiction prod- uct line.B Af a nianrp Name Language Interactive Fiction: Six Mixture of BASIC and Micro Stories machine code Type Computer Adventure-type user- Radio Shack TRS-80 Model interactive game I with one disk drive and 32 K bytes of memory Manufacturer Adventure Documentation International Several screens of informa- POB 3435 tion within the program Longwood FL 32750 (305) 862-6917 Audience Adventure enthusiasts and Price people who like role-playing $15 games Format 5-inch floppy disk 436 September 1981 © BYTE Publications Inc SURE THIIUG HR5TER. 50 I FIND YOU NOT GUILTY UNDER THE CONDITION YOU \DE-BUG. THE ROBOT "~~y~s- — ^YOU GOT IT JUDG-EY VJUD&EYl READ ME THAT NEW LISTING III BURN IT INTO THE NEW, iEPROM. ~ oooo D8 CLD 000/ Af 01 B/P LD/»*oi OOOJ SDOZ 19 STASI902 0006 20 SI FE JMPi F£|l OO09 DO P4 BNE SIP 0O08 29 AND NOW THE TEST...WHAT5 2+2? HERE CHILD5 PLRV. JT5 H.DDDnOl . September 1981 © BYTE Publications Inc 437 INDIVIDUAL/NET WORD PROCESSOR S-100, 7 Slot, 360K Double Density DUAL/NET SMALL BUSINESS APPLICATIONS Up To 4 Terminals Can Be Slaved Off Master LOCAL/NET TELEPHONE/NET Configurability SKTEM/NET LARGE SYSTEM NUCLEUS Hard Disc and 8" Floppy Any Combination of Master or Slave MASTER/NET "BUY" WORD FOR THE 1980's NETWORKING is the newest 'buzzword' in microprocessors. Delta Products has produced a superior hardware system that cannot be matched in .either cost or performance. Don't buy a system that has "designed-in" limitations; check the following: PERFORMANCE This is where DP/NET® beats them all. Delta does multiuser and multitasking operations by using distributed processors. DIGITAL RESEARCH has provided a new operating system (CP/NET®) which combines MP/M® and CP/M 2.2® into the world's most powerful microcomputer system. The system cannot be bogged down by adding more users. High-speed DMA transfers from Host to Slave, allow many processors to share workloads. (There can be 3 processors at EACH user terminal; a ZSOfor screen function, and a pair of 8085/8088 for main processing.) FLEXIBILITY One of the most important advantages of DP/NET® is that you never have to purchase more system than you currently need. Your system can start with a 5" minifloppy 32K terminal for under $3000.00. Adding a Second terminal and additional mass storage is as simple as the original purchase. Networking up to 16 OR MORE intelligent and semi-intelligent work stations can follow in perfect step with the growth of your Company and requirements. COST Since you never buy more computer power than you need, the system cost is matched to the demand to be placed upon it. DELTA PRODUCTS has a lot of experience in building micros, with over 2000 DELTA systems now in the field. DELTA component cost has always been extremely competitive. DELTA'S new "networking system" is a natural and simple combination of the competitive "good deals" we have been offering for some time. SOFTWARE A computer system to the end user IS THE SOFTWARE. All CP/M® compatible programs run perfectly on the DP /NET®. DELTA PRODUCTS is currently writing its' own high-performance custom data base, screen editor, order entry/inventory, and accounting packages in PL/1®. Target release date for the complete package is November, 1981. SOLD ONLY THROUGH DEALERSHIPS CALL FOR YOUR NEAREST REPRESENTATIVE DELTA PRODUCTS 15392 Assembly Lane Huntington Beach, CA 92649 TELEPHONE: (714) 898-1492 PRODUCTS TELEX: 681-367 DELTMAR HTBH MP/M, CP/M2.2, PL/1 & CP/NET ARE REG. TM OF DIGITAL RESEARCH INC. Circle 395 on inquiry card. AMAZING VALUES. FROM (m)etatronics ^ ' CORPORATION VISA RETAIL STORE 22297EUCLID AVENUE EUCLID, OHIO 44117 (EAST 222nd & EUCLID AVE.) MOST ORDERS SHIPPED WITHIN ONE BUSINESS DAY TRS-80 is a trademark of the Radio Shack Division of Tandy Corporation. PLAIN JANE is a Trademark of Meta Technologies Corporation. PRICES IN EFFECT Sept. 1, 1981 THRU September 30, 1981, Prices, Specifications, and Offerings subject to change without notice. • Add $3.00 for shipping & handling. •$3.00 EXTRA for C.O.D. • Ohio residents add 5 1 /2% sales tax. TO ORDER CALL TOLL FREE 1-800-321-9390 IN OHIO, call (216) 289-1210 (COLLECT) OFFICES 26111 BRUSH AVENUE EUCLID, OHIO 44132 (SEND MAIL ORDERS HERE) 1981 by Metatronics Corp. 440 BYTE September 1981 Circle 213 on inquiry card. What's New? SYSTEMS The Stratos The Stratos is a 4 MHz, Z80-based computer with 80 K bytes of progammable memory and 1 .2 megabytes of floppy-disk storage (expandable to 5 mega- bytes). Stratos features a ROM (read-only memory) monitor, CP/M 2.2, the Spellbinder word- processing program, a CBASIC or a Pascal compiler, business and personal-reminder software, printer driver routines for most printers, and two RS-232C ports. Additional features of the Stratos include a memory- mapped video controller, utilities that allow many combinations of disk drives and formats to be con- nected, a light pen, and an AC- controller port. The Stratos micro- computer is housed in a teak- wood case. Contact Symbiotic Systems Inc, 118 Naglee Ave, Santa Cruz CA 95060, (408) 425-5533. Circle 501 on inquiry card. A Ralr Thing Indeed Inside Rair Microcomputer Cor- poration's Black Box 3/30 is a 5-megabyte Winchester hard disk and a dual-sided, double-density floppy-disk drive for backup. The Black Box 3/30 features either the CP/M or MP/M operating systems and an IEEE-488 bus with 64 K bytes of programmable memory and 16 programmable I/O (in- put/output) ports. For applications and develop- ment, Rair offers BASIC, PL/1, FORTRAN, COBOL, and Pascal. The Black Box 3/30 costs S7500. Contact Rair Microcomputer Cor- poration, 4101 Burton Dr, Santa Clara CA 95050, (408) 988-1 790. Circle 502 on inquiry card. Tiny BASIC Computer Board The K-8073 single-board com- puter features National's INS8073 Tiny BASIC Microinterpreter microprocessor. Features include serial communication data rates from 1 1 to 4800 bps (bits per second), a cassette-tape I/O (in- put/output), 8 K bytes of EPROM (erasable programmable read- only memory), 1 K of program- mable memory with expansion to 8 K externally, STD bus structure, remote controller for single-wire data control from remote stations, and 24 bidirectional I/O lines. The board is supplied with a 2 K ROM (read-only memory) of develop- ment utilities and a real-time calendar/clock. The K-8073 requires + 5 V and costs $388. Contact Transwave Corporation, RD 1 Box 489, Van- derbilt PA 15486, (412) 628-6303. Circle 503 on inquiry card. The LNW80 Microcomputer The LNW80 microcomputer is software-compatible with the TRS-80. It includes a 4 MHz, Z80A microprocessor, high-reso- lution black-and-white and color graphics, 12 K bytes of ROM (read-only memory), 1 6 K bytes of programmable memory, upper- and lowercase display, reverse video, an RF (radio frequency) modulator, expansion bus, cas- sette interface, and power supply. The LNW80 costs $ 1 664 with a black-and-white monitor and a single 5-inch floppy-disk drive, but it can be purchased without peri- pherals for S 1 200. For details, contact LNW Research Corpora- tion, 14661 C Myford Rd, Tustin CA 92680, (714) 544-5744. Circle 504 on inquiry card. Xerox 820 Microcomputer The Xerox 820 microcomputer can be used as a word-processing system, a business computer, or both. The basic 820 system in- cludes two RS-232C and two par- allel ports, dual 5-inch floppy-disk drives each with a 92 K-byte un- formatted capacity, a standard keyboard, and a 12-inch black- and-white video-display monitor with 24 lines by 80 characters. The 820 features a -Z80 micro- processor with 64 K bytes of pro- grammable memory and 4 K bytes of ROM (read-only mem- ory). The CP/M operating system and applications software, in- cluding CBASIC-2, COBOL 80, MBASIC, and word-processing programs, are available. A word- processing system utilizing Word- Star and the SuperCalc electronic spreadsheet are available as op- tions. It can be connected to the Ethernet communications net- work. The Xerox 820 costs S2995 and is available from Xerox and authorized dealers. For further de- tails, contact the Office Products Division, Xerox Corporation, 1341 W Mockingbird Ln, Dallas TX 75247. Circle 505 on inquiry card. Sierra 4000 The Sierra 4000 computer is an S-I00, Z80-based computer that features dual floppy-disk drives and a hard disk. Together, these devices provide a total of up to 96 megabytes of storage. A two- drive hard-disk system is optional. For more information, contact Sierra National Corporation, 5037 Ruffner St, San Diego CA 9211 1, (714) 277-4810. Circle 506 on inquiry card. September 1981 © BYTE Publications Inc 441 What's New? SOFTWARE MP/M-86 Operating System Digital Research's MP/M-86 is a multiuser operating system for 8086-based microcomputers. It is compatible with the CP/M-86 operating system and programs. MP/M-86 will support networking capabilities through CP/NET. It allows multiple users to execute programs with only one copy of the object code in main memory. Other features of the MP/M-86 operating system are file and record lockout, standard in- put/output, and internal gueue mechanisms that support mutual exclusion, pipes, synchronization and communication between multiple tasks. Customized operating environments can be defined within the MP/M-86 structure. For more information, contact Digital Research Inc, POB 579, 801 Lighthouse Ave, Pacific Grove 93950, (405) 649-3896. Circle 507 on inquiry card. New Personal Software Products Personal Software has five new items in its product line: a new version of the VisiCalc business and planning program and four new VisiCalc-compatible pro- grams. The new VisiCalc pro- gram includes a full implementa- tion of a program-independent data-storage format called Data Interchange Format. It allows transfers of files between VisiCalc and other text and data programs regardless of format structure. An Edit command lets users edit for- mulas without retyping them. Al- so Boolean functions and the abil- ity to choose specific elements in a list based on the results of another calculation are featured. The new VisiCalc costs S 199.95. VisiPlot is a new VisiCalc-com- patible program with high-resolu- tion color plotting and graphics. It costs 5179.95. VisiDex is a per- sonal-information system that can handle mailing lists and per- sonal calendars. It costs S 199.95. VisiTrend/VisiPlot is a combina- tion of VisiPlot graphics and a program for time-series manipula- tion, trend forecasting, and des- criptive statistics. Its suggested price is S259.95. Then, there is VisiTerm, which can send and re- ceive files from the other Visi- programs over telephone lines to any other computer. VisiTerm is $149.95. For details, contact Personal Software Inc, 1330 Bordeaux Dr, Sunnyvale CA 94086, (408) 745-7841. Circle 508 on inquiry card. Music Reader Music Reader I shows you the notes while it plays the melody through the Apple IJ's speaker. You can learn to read treble and bass clefs, note values, time and key signatures, sharps and flats, and complex rhythms because the program plays what you write. Music Reader I comes on a floppy disk and costs S30. Con- tact Shafer Software, 749 W Fre- mont Ave, Sunnyvale CA 94087. Circle 509 on inquiry card. Applesoft Compiler The Hayden Book Company's Applesoft compiler can increase a BASIC program's speed as much as ten times and occupies only 3.2 K bytes of memory. The 17-pass compiler generates true machine code. High-resolution graphics and shape tables are supported, and multiple programs can reside in memory at the same time. Hayden's Applesoft compiler requires a 48 K-byte Apple II Plus or Apple II with Applesoft in ROM (read-only memory), the Auto- start ROM, and at least one floppy-disk drive. The compiler can be used with multiple- and hard-disk drives, and it can work on systems using the Apple Lan- guage Card or Microsoft RAM- Card. The compiler costs $200. Contact Hayden Book Company Inc, 50 Essex St, Rochelle Park NJ 07662, (201) 843-0550. Circle 510 on inquiry card. Air Combat Game The Computer Air Combat game recreates World War II aerial combat. The player(s) choose from thirty-six fighters or bombers. Each plane is rated in historical accuracy and detail for firepower, speed, maneuverabili- ty, damage-tolerance, and climb- ing and diving ability. Five scenar- ios are provided to refight actual combat engagements. Computer Air Combat includes a rule book, two map-board charts, and three player-aid charts. The game is available for 48 K-byte Apple lis with Ap- plesoft in read-only memory and a floppy-disk drive. It costs $59.95. Contact Strategic Simula- tions Inc, 465 Fairchild Dr, Suite 1 08, Mountain View CA 94043, (415) 964-1353. Circle 511 on inquiry card. 442 September 1981 © BYTE Publications Inc What's New? SOFTWARE Language for Education— Tl Logo Tl Logo was designed for the TI-99/4 microcomputer. It is the end result of collaboration be- tween Texas Instruments and the Massachusetts Institute of Tech- nology. Tl Logo has been tested in schools in New York City and Dallas, Texas, with students rang- ing from nursery school through the twelfth grade. Tl Logo is structured so that children can successfully use the computer with little formal in- struction. Students can draw geo- metric figures and designs and program the movement of special graphics figures. To work with the language, students must teach the computer what to do, which makes learning with Tl Logo an interactive process rather than a feedback situation. Using Tl Logo, students make on-the- spot judgments as to whether their approach to a problem is ef- fective. A Tl Logo set-up requires the software and a TI-99/4 computer with a video display, floppy-disk drive and controller, and a mem- ory-expansion unit. Tl Logo soft- ware costs S299.95. For more in- formation, contact the Customer Relations Department, Texas In- struments Inc, POB 53, Lubbock TX 79408. Circle 512 on inquiry card. The MDBS-QRS The MDBS-QRS add-on lets nonprogrammers interrogate any Micro Data Base Systems data base using English-like com- mands. Utilities defining macroin- structions are included. Titles and synonyms for the various data- base entities can be defined. A report generated in response to a query can be displayed in a stan- dard or customized format using the Report Writer feature. String comparisons are allowed, and an optional conditional clause can be included for highly selective data retrieval. Existing data values can be modified. It is available for S300 from Micro Data Base Sys- tems Inc, POB 248, Lafayette IN 47902, (317) 448-1616. Circle 513 on inquiry card. CP/M Cross-Assemblers Avocet Systems's XASM family of cross-assemblers can now run on 8080 and Z80-based micro- computers under CP/M and simi- lar operating systems. Pseudo- operation codes support nested conditional assembly, listing-for- mat control, definition of mne- monic synonyms, and the inclu- sion of external source files. The assemblers generate object files in the Intel HEX format. Other members of the XASM family of cross-assemblers are de- signed for 6805, 680 1, 1 802, 6502, 6800, COP400, and other microprocessors. Each XASM cross-assembler costs S200; man- uals cost S25. Contact Avocet Systems Inc, 804 S State St, Dover DE 19901, (302) 734-01 51. Circle 514 on inquiry card. Music and Animation Program Rainbow Writer is a graphics, text, music, and animation pro- gram that runs on the Apple \\ and the Apple II Plus computers. It can create special effects that feature color, animation, letters, shapes, and sounds. The pro- gram lets users define character fonts and choose between nine sizes and nineteen different colors of upper- and lowercase English and Greek letters. Musically, the program offers six chromatic oc- taves and note sustain. Music data can be stored on disk. The suggested retail price is S39.95. For details, contact Per- sonal Software Inc, 1 330 Bordeaux Dr, Sunnyvale CA 94086, (408) 745-784 1 . Circle 515 on inquiry card. September 1981 © BYTE Publications Inc 443 What's New? PUBLICATIONS Evaluation of Educational Programs School MicroWare Reviews contains user evaluations of in- structional programs and pack- ages for the Apple, PET, and TRS-80 microcomputers. Each edition includes an index to evaluations in other publications. The reviews are organized by school department and within that by subject. Each review con- tains comments about the quality of the documentation, the in- structions to users given by the programs, the student-computer dialogue, and other concerns. The evaluation includes the pro- ducer, price, hardware configura- tion, storage medium, program type, grade level, and functional description. School MicroWare Reviews costs $30 per edition. Also available is the School MicroWare Directory. A sub- scription to it costs $20 per year. It contains descriptions of over 900 programs. If you are a directory subscriber and provide a course- ware evaluation that follows a form provided by the publishers, you can receive Reviews free if your evaluation is published. Nondirectory subscribers whose material is published receive Reviews at half price. Contact Dresden Associates, POB 246, Department BY-1, Dresden ME 04342, (207) 737-4466. Circle 516 on inquiry card. Literature on Computer Science and Technology The United States Government Printing Office has books and manuals on computer-related subjects for sale. For information on titles and ordering, contact the Superintendent of Documents, US Government Printing Office, Washington DC 20402. Circle 517 on inquiry card. Microsoft Catalog Microsoft Consumer Products has a new catalog that describes all of the software products it pro- duces and sells. The free catalog is available at Microsoft dealers or by contacting the company at 400 1 08th Ave, NE, Suite 200, Bellevue WA 98004, (206) 454- 1315. Circle 518 on inquiry card. Structured Requirements Definition Structured Requirements Definition, by Ken Orr, covers re- cent advances in systems theory, tools, and methodology. The book is written for analysts, pro- grammers, managers, and users. It is available for $25 from Ken Orr and Associates Inc, 715 E 8th, Topeka KS 66607, (800) 255-2459; in Kansas (913) 233-2349. Circle 519 on inquiry card. Courseware Evaluation Guidelines Guidelines for Evaluating Computerized Instructional Ma- terials is a guide for buying and selling instructional software. Previous programming exper- ience is not assumed in this book for users and creators of edu- cational computer software. Divi- sions within the guide explain ways to determine what sort of software is needed, how to look for it, and minor modifications that can be made. Guidelines for Evaluating Computerized Instructional Ma- terials costs $3.75. Contact the National Council of Teachers of Mathematics, 1 906 Association Dr, Reston VA 2209 1, (703) 620-9840. Circle 520 on inquiry card. FORTH Beginner's Book Starting FORTH is for novice FORTH programmers. It em- braces such topics as defining words, compiling words, vec- tored execution, virtual memory, and number-scaling techniques. Many programming examples and illustrations are featured. The book is published by Prentice-Hall Inc. For more information, con- tact FORTH Inc, 2309 Pacific Coast Hwy, Hermosa Beach CA 90254, (2 1 3) 372-8493. Circle 521 on inquiry card. DEC LSI/PDP-1 1 Systems Catalog A catalog featuring DEC (Digital Equipment Corporation) LSI/PDP-11 computer systems, peripheral equipment, and soft- ware is available from Compu- mart Corporation. Compumart distributes equipment and sys- tems from DEC and peripherals from other major manufacturers. For your copy, contact Compu- mart Corporation, 65 Bent St, POB 568, Cambridge MA 02 1 39, (617) 491-2700. Circle 522 on inquiry card. Software Protection The legal protection of com- puter software is examined in Computers, Copyright and the Law. This report was developed to help software authors make decisions about protecting their product's proprietary rights. The report encompasses the theories behind software protection, but it emphasizes protection methods and their relationship to software sales, leasing, and licensing. Con- tact Educational Programming Systems, 1328 Baur Blvd, St Louis MO 63132, (314) 991-0300. Circle 523 on inquiry card. 444 September 1981 © BYTE Publications Inc What's New? PUBLICATIONS International Software Directory The International Microcom- puter Software Directory is a reference source of new and established software for all ap- plications and systems. The direc- tory is divided into sections listing programs for specific computers, describing categories of pro- grams, and a section for users wishing to buy from a particular software house. Programs are cross-referenced throughout the sections. Details as to date of release, warranties, distributors, medium, source code, compatible systems, special configurations needed, limitations, and prices are all provided. The directory is availalble for S29; updates are available every six months. System-specific direc- tories that are extracted and cross-referenced from the main data base are available for SI 2. These directories list programs written for the Apple, TRS-80, and PET computers, and the CP/M operating system. The directory is available from Imprint Software, 420 S Howes, Fort Col- lins CO 80521, (303) 482-5574. In England, contact Imprint Soft- ware, 16 Milton Ave, Highgate, London, N6. Circle 524 on inquiry card. 600 Microprocessors Cross-Referenced The Microprocessor IC D.A.T.A. Book lists characteristics of over 5000 integrated circuits, including over 600 microprocessors and associated programmable and read-only memory devices, interface-support circuits, pro- cessor architecture, and manufac- turer software support. Pro- cessors are cross-referenced by generic numbers, technical characteristics, logic, block draw- ings, instruction sets, outline drawings, and manufacturers. The book is published twice a year. The subscription rate is S55 per year. Contact D.A.T.A. Inc. POB 26875-PR, San Diego CA 92126, (800) 854-7030; in California (714) 578-7600. Circle 525 on inquiry card. Computer Music Journal A special two-part issue of Computer Music Journal, a quarterly from MIT Press, surveys the applications of artificial in- telligence to music. Articles deal with devices that will be capable of listening to, understanding and playing music, and reports on research underway that hopes to explain human musical cognition. Other topics include the use of the computer as an assistant for musical-score analysis and com- position, automatic music transcription from sound to score, multilevel graphic representation of scores and sound in natural languages, intelligent music in- struments, new theories of music, and an introduction to LISP. A subscription to the Com- puter Music Journal costs S25 per year. Contact the MIT Press, 28 Carleton St, Cambridge MA 02142, (617) 253-2889. Circle 526 on inquiry card. Software- Vendor Directory The fourth edition of the Soft- ware Vendor Directory contains 1001 software vendors, 4195 products, and 80 hardware and 200 software categories. The directory costs $57.95. Optional- ly, the directory can be purchased for S 1 00, which includes two up- dates at six-month intervals. A single update costs $25. Also, a CP/M disk version is available for $78. Contact Micro-Serve Inc, 250 Cedar Hill Ave, Nyack NY 10960, (914) 358-1340. Circle 527 on inquiry card. Guide to Published Material on Computers Bookguide 1 : Microprocessors and Microcomputers covers pub- lications that describe the con- cepts, applications, and potential of microprocessor devices. It lists authors, abstracts, publishers, and prices for nearly 500 titles from 39 publishers. Books on more than 50 topics ranging from histories to dictionaries, microcomputer architecture, pro- gramming techniques, personal computers, and artificial in- telligence, are listed. Bookguide 1 is available for $11.50 from Leatherleaf Book Services Inc, POB 28, Pembina ND 5827 1 . Circle 528 on inquiry card. Books for the Apple MICRO/Apple 1 is the first volume of a series of books that will contain articles from Micro, The 6502 Journal. The articles contain Apple program listings, which are on a floppy disk that accompanies the book. MICRO/Apple 1 costs $24.95, in- cluding the disk. Contact Micro Ink Inc, POB 6502, Chelmsford MA 01824. Circle 529 on inquiry card. September 1981 © BYTE Publications Inc 445 What's New? PERIPHERALS Connect an Olympla ESIOOtoa Microcomputer Using the Ren Tec RS-232C in- terface, the Olympia ES 1 00 type- writer can provide letter-quality printing and still function as a standard typewriter. The Ren Tec RS-232C uses CMOS (comple- mentary metal-oxide semiconduc- tor) logic. It accepts an RS-232C serial or a parallel interface; ac- commodates odd, even, or no parity; features handshake logic; and also provides any character- translation format. The Ren Tec ES costs S295. For additional details, contact Ren- aissance Technology Corpora- tion, 3347 Vincent Rd, Pleasant Hill CA 94532, (415) 930-7707. Circle 530 on inquiry card. Color Printer for the Apple The OmniColor II is a color-ink jet printer with a 16 K- or 32 K- byte buffer. Intended for the Ap- ple II, software for 3.3 DOS is in- cluded. The OmniColor II uses eight colors, prints at 40 cps (characters per second), and can print paper up to 13 inches wide, as well as print overlay pages and screens. It features normal or ex- panded print and the ability to dot-plot any section of memory. Contact Omnico Computer Cor- poration, 3300 Buckeye Rd, At- lanta GA 30341, (404) 455-8460. Circle 532 on inquiry card. Double Your Graphics Capability The Double Hi-Res card pro- vides two levels of grey scale and can display 80 columns by 24 lines. It is designed for the Apple II or III and is compatible with the Apple Ill's super-high-resolution graphics. Character sets can be defined with the Define Font pro- gram supplied. The Double Hi-Res features italics, underline, multi- ple-character sets as well as graphics on the same screen, pro- portional spacing, mathematics symbols, and APL- and Japanese- character sets. Multiple-character sets can reside in memory simultaneously. The price for the Double Hi-Res card and support software on a floppy disk is $295. Contact Spies Laboratories, POB 336, Lawn- dale CA 90260, (213) 644-0056. Circle 533 on inquiry card. The Rhythm Box The Rhythm Box synthesizes bass and snare drums, wood blocks, short and long cymbals, hand claps, and tom-toms. It is programmable in Level II BASIC or assembly language. The unit has a phono jack for connection to an audio system, a power supply, a manual including BASIC and as- sembly-language software ex- amples, and a selection of rhythm charts. The Model RBX-T for the TRS-80 Model I Level II is available for SI 49. The Model RBX-S is for S- 1 00, Apple II, PET, and other systems. It connects to 9600 bps (bit per second) serial interfaces using either RS232C or 20 mA current- loop levels. It costs $179. For more information, contact New- tech Computer Systems Inc, 230 Clinton St, Brooklyn NY 11201, (212) 625-6220. Circle 531 on inquiry card. Thin Floppy-Disk Drives The Thinline 8-inch floppy-disk drives are 5.9 cm (2 3 /, inches) high and weigh 7 pounds. These double-sided head drives can be turned on and off by control sig- nals from the interface. Head positioning is accomplished by a band-driven carriage. The door arrangement has been simplified by using a lever that closes and positions the disk in the drive. The Thinline drives record at 48 and 96 tracks per inch. There are two models avail- able. The TM 848- 1 stores 600 K bytes on one side of a disk and TM 848-2 stores 1. 2 megabytes on both sides. The drives can be used in single- and double-density applications. For more informa- tion, contact Tandon Corpora- tion, 20320 Prairie St, Chatsworth CA 9l3ll, (2 1 3) 993-6644. Circle 543 on inquiry card. 1 1 by 1 1 Digitizer The Demi-Pad is an 11- by 1 1-inch digitizer tablet featuring a 200-sample-per-second rate. It in- cludes a Z80-based interface, which provides RS-232C ASCII (American Standard Code for In- formation Interchange) or binary- coded data, and 0.001 -inch resolution. The Demi-Pad comes with a pen or stylus cursor. Options include a power sup- ply, 1 6-button stylus or crosswire cursor, X Y display, and an ASCII keyboard. Priced at $990, the Demi-Pad is available from GTCO Corporation, 1055 First St, Rock- ville MD 20850, (301) 279-9550. Circle 534 on inquiry card. 446 September 1981 © BYTE Publications Inc What's New? MISCELLANEOUS 5-Inch Drives for the TRS-80 Model III Percom Data Company has 5-inch floppy-disk drives for the TRS-80 Model III. Systems can be ordered with either 40- or 80- track drives rated for double- and single-density operation. The first two drives mount inside the com- puter; the others mount exter- nally. The first internal drive comes with a four-drive con- troller, a two-drive power supply, cables, a double-density disk op- erating system, and mounting hardware. The four-drive controller fea- tures data-separation and write- precompensation circuitry. It is capable of handling two-headed drives and single-density 8-inch drives. The computer can use the Model Ill's disk operating system or Percom's OS-80/III. The first in- ternal drive sells for S 749.95 in the 40-track version and $914.95 in the 80-track version. The second internal drive in- cludes the drive mechanism, elec- tronics, and installation hard- ware. It costs S3 1 5 in the 40-track version and $474.95 in the 80- track version. Single external 40-track drives are $439, and the dual 40-track drives are $878. Cables for the ex- ternal drives are $29.95. For de- tails, contact Percom Data Com- pany Inc, 2 1 1 N Kirby, Garland TX 75042, (800) 527-1592; in Texas, (214) 272-3421. Circle 535 on inquiry card. ^5 ^ »! Speech Processor The Mimic speech processor converts speech to digital data and reconstructs the digital repre- sentation to analog form for re- production through a speaker. The system can be used for digital speech-communications applica- tions without a computer. The speech data rate is user-selec- table, with speech reproduced at rates from 9600 to 20,000 bps (bits per second). There are four versions of the Mimic speech processor: a S20 bare board, an assembled and tested module for $79, a $149 system configured for parallel- port interfacing, and a TRS-80- compatible plug-in version for $169. Documentation, including program examples and schemat- ics for an S-l 00 bus interface, is also available. Contact Mimic Electronics Company, POB 921, Acton MA 01720. Circle 536 on inquiry card. Small-Systems Software and Services Sourcebook Small Systems Software and Services Sourcebook lists and cross-indexes software and ser- vices available to users of mini- and microcomputers in business, professions, and government. En- tries include software and service listings related to system soft- ware, application software, and consulting and services in medi- cal, business, investment, model- ing, and other applications. The book has some marketplace list- ings and display advertising. For more information, contact Infor- mation Sources Inc, 1807 Glen- view Rd, Glenview IL 60025, (312) 724-9285. Circle 537 on inquiry card. September 1981 © BYTE Publications Inc 447 What's New? MISCELLANEOUS Buy and Sell Horsetrader is a publication for buyers and sellers of computer equipment. It features used, new, and rebuilt computers, terminals, printers, and other items. For in- formation on ad or subscription rates, contact Horsetrader, POB II 71 2, Santa Ana CA 92711, (714) 832-0628. Circle 538 on inquiry card. Book Catalog Telecom Library's 1981 catalog contains more than 300 titles of books, periodicals, training manuals, and audio cassettes for information professionals. The catalog features books on telecommunications manage- ment, data communications, data processing, computer program- ming, office automation, word processing, teleconferencing, satellites, and cable television. The catalog is free from Telecom Library Inc, 205 W 1 9th St, New York NY 1001 1, (212) 691-8215. Circle 539 on inquiry card. CBASIC Program Directory Compiler Systems Inc has published a directory listing 157 business-application programs as well as vertical-market packages written in CBASIC available from 30 software vendors. The CBASIC Software Directory pro- vides a description of each pro- gram, its memory requirements, and the vendor's name, address, and telephone number. Unless noted, all products support CP/M and MP/M and require at least one floppy-disk drive. The direc- tory is available for S 14.95 from Compiler Systems Inc, 37 N Au- burn Ave, POB 145, Sierra Madre CA 91024, (213) 355-1063. Circle 540 on inquiry card. sMtsawpn*- f- 1 MX It: #M« ■ .« ~*Kmi * ■ "• 1 i] • ' ,3mk s*V — — —1 ' " ~ : r ~ 1 %- . flFf»-3Sfc ■"■ v, 1 fef B '""' 1 B MHMI^BfeSsF^^M Br' ■■L—H wt Hill Hmm !»W E • raT 5 J^a.T>-tiX... '.-... ' "j '-■*-' 5r*STT , ■•'' 4* - 1 _^ — C £ y V ■i-T1i»- w. w .£, _„r ' y A .- ■ ■■ ■ .* L Kb . . j Single-Board Computer A single-board computer with analog, serial, and power-control I/O (input/output) has been an- nounced by Wintek. The board features a 6801 or 68701 micro- processor with 2 K bytes of ROM (read-only memory), 128 bytes of programmable memory, and an internal and an external timer. The 1 2-bit A/D (analog-to-digital) converter can be configured for eight single-ended or four dif- ferential inputs. The eight digital I/O lines can be configured for any mix of AC or DC inputs or outputs. The serial I/O allows half-duplex 20 mA current-loop communication to a host com- puter at software-selectable rates. The prices range from S88 to S295, depending on options and quantity. Applications include re- mote data acquisition, machinery control, and energy manage- ment. Contact Wintek Corpora- tion, 1801 South St, Lafayette IN 47904, (317) 742-8428. Circle 541 on inquiry card. Software for the Atari Personal Software has intro- duced MicroChess and Checker King for the Atari 400 and 800 microcomputers. Both games fea- ture an on-screen, real-time clock for game timing. The games re- quire 8 K bytes of memory and are priced at S 1 9.95 each, on cas- sette. The MicroChess program turns a color-display screen into a chessboard. It has eight selectable levels of play, plays by tourna- ment rules, and allows no illegal moves. Checker King allows single, double, and triple jumps, forces jumps, and performs according to the tournament rules of checkers. For details, contact Personal Soft- ware Inc, 1 330 Bordeaux Dr, Sun- nyvale CA 94086, (408) 745- 784 1. Circle 542 on inquiry card. 448 September 1981 © BYTE Publications Inc AD & DA CONVERTER Z80 MICROCOMPUTER 6522 APPLE II INTERFACE JBE one channel A-D & D-A Converter can be used with any system having parallel ports • Interfaces with JBE Parallel I/O Card • D-A conversion time — 5 /js • A-D conversion time — 20 >js • Uses JBE 5V power supply • Parallel inputs & outputs include 8 data bits, strobe lines & latches • Analog inputs & outputs are medium impedance to 5 volt range. ^ 79-287 Bare Board $39.95 ASSM, $78.95 Kit $59.95 6502 MICROCOMPUTER JBE's 4 1 /2x3 1 /< dedicated controller features: • 1024 bytes RAM (two 21 14s) • 2048 bytes EPROM (2716) • Uses one 6522 VIA (comp. doc. incl.) • Interfaces with JBE Solid State Switches & A-D & D-A Converter • Uses JBE 5V power supply •2716 EPROM available separately (2716 can be programmed with an Apple II & JBE EPROM Pro- grammer & Parallel Interface) • 50 pin connector included In kit & assm. 80-153 ASSM. $110.95 Bare Board $49.95 Kit$ 89.95 SOLID STATE SWITCH 'Jfc — ^•♦flfl- «srsll Hr^fl '^^ffl *srsf?' Your computer can control power to your printer, lights, stereo & any 120 VAC appliances up to 720 watts (6 amps at 120VAC). Input 3 to 15VDC • 2-14MA TTL compatible • Isolation — 1500V • Non zero crossing • Comes in 1 or 4 channel version. 79-282-1 Bare Board $6.95 79-282-4 Bare Board $24.95 ASSM. $13.95 Kit $10.95 ASSM. $49.95 Kit $39.95 APPLE II DISPLAY BOARD JBE's 4-1/8"x3-1/4" single board dedicated computer is designed for control functions. It features: • A Z80 Microprocessor software compatible with the 280, 8060 & 8085 Microprocessors • Uses a Z80 PIO chip for I/O which has 2 independent 8 bit bidirectional peripheral interface ports with handshake & data transfer control • Uses one 2716 EPROM (2K) & two 21 14 RAM memories (1K) • Single 5V power Supply at 300MA req. • Clock frequency is 2MHz, RC controlled • Board comes with complete doc. • 50 pin connector is included *2716 EPROM available separately. 80-280 ASSM. $129.95 Bare Board $49.95 Kit $1 1 9.95 PRINTER INTERFACE JBE Parallel Printer Interface interfaces your Apple II® to Centronics" compatible printers. This 3" x 4" board features: on board ROM compatible with Integer Basic, Applesoft* and Pascal* • Has one 8 bit parallel latched output port with selectable positive or negative strob e an d one bit input selectable for Ready or Reedy • Cable and Connectors available separately. 80-297 ASSM. $79.95 Kit $69.95 4 ft. Std. Dip Jumpers 16 pin $4.25 Champ Connector $ 9.95 POWER SUPPLIES • Use wall transformers for safety • Protected against short circuit and thermal breakdown. 5 VOLT POWER SUPPLY Rated at 5V 500MA • Operates JBE A-D & D-A Converter, Z80 & 6502 Microcom- puters, 8085 & 8088 Microcomputers. 80-160 ASSM. $20.95 Bare Board $8.95 Kit $16.95 ± 12 VOLT POWER SUPPLY Rated at ± 12V 120MA • Can be used as a single 24V power supply • Ideally suited to OP-AMP experiments. 80-161 ASSM. $22.95 Bare Board $8.95 Kit $1 8.95 80-144 Bare Board $25.95 ASSM. $49.95 Kit $42.95 • Has run-stop, single step switch • Has 16 address LEDs, 8 data LEDs & 1 RDY LED • All lines are buf- fered. ICS 6502 $9.95 6522 $9.95 Z80CPU $9.95 Z80 PIO $9.95 2716 $14.95 2716 Programmed • Interfaces printers, synthesizers, keyboards, JBE A-D & D-A Converter & Solid State Switches • Has handshak- ing logic, two 6522 VIAs & a 74LS05 for timing • Inputs & outputs are TTL compatible. 79-295 ASSM. $69.95 Bare Board $39.95 Kit $59.95 2716 EPROM PROGRAMMER JBE 2716 EPROM Pro- grammer was designed to program 5V 2716 EPROMS • It can also read 2716s. It interfaces to the Apple II using JBE Parallel I/O Card & four ribbon cable con- nectors • An LED indicates when power is being applied to the EPROM • A textool zero insertion force socket is used for the EPROM • Comes with complete doc. for writing and reading in the Apple II or Apple II + • Cables available separately. 80-244 ASSM. $49.95 Bare Board $24.95 Kit $39.95 2 Ft. Ribbon Cable $ 4.25 BARE BOARDS APPLE II EXTENDER BOARD SW'xZVt". Price Includes 50 pin Con- nector. 80-143 $12.95 8085 3 CHIP SYSTEM State-of-the-art system using an 8085, 8156 & either an 8355 or 8755 • Instruction set 100% upward com- patible with 8080A. Bare Board $24.95 8088 5 CHIP SYSTEM An 8086 family microcomputer system using an 8088 CPU, 8284, 8155, 8755A & an 8185. Bare Board $29.95 CRT CONTROLLER This intelligent CRT Controller uses an 8085A CPU & an 8275 Integrated CRT Controller. It features: • 25 lines (80 Char./line) • 5x7 dot matrix • Upper & lower case • two 2716s (controller & char, generator) • serial interface RS232 & TTL • baud rates of 110, 150, 300, 600, 1200, 2400, 4800 & 9600 • keyboard scanning system • unen- coded keyboard is req'd • uses + 5V & ± 12V power supplies • Doc. includes program listing & composite video cir- cuit. $39.95 $19.95 Bare Board only (Doc. incl.) Programmed 2716s each $19.95 all products are available from john bell engineering • p.o. box 338 redwood city, ca 94064 • add sales tax in california • add 5% shipping & handling (415)367-1137 10% outside u.s.a. VISA Circle 38 on inquiry card. BYTE September 1981 449 What's New? MISCELLANEOUS Compact Fluorescent Display Panel The itron square-format DM128X128C 128 by 128 dot matrix display panel is slightly over 76.6 by 76.55 mm square (3 inches) and only 20 mm (0.8 inch) thick. It is capable of display- ing special symbols, geometric patterns, graphics, block and cur- sive alphanumerics, continuously scrolling images, and lighted areas. Each dot is individually ad- dressable, and ascenders and de- scenders, script lettering, linear graphics, and charts can be pro- duced. For more information, contact Noritake Electronics Inc. 224 1 Hawthorne Blvd, Torrance CA 90505, (213) 373-6704. Circle 544 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. Piggybacked Prototyping Boards Circbords are perforated proto- typing boards that can add 24 square inches of working area and 20 to 60 DIP (dual-inline package) positions when mounted on spacers, piggyback- style, on edge connector boards. Circbords can also be installed us- ing card guides or in aluminum extrusions. The Model 8001 is designed for solder connections. It holds up to twenty 16-pin integrated circuits. The Model 8002, for wrapped wire, can hold up to thirty-five 1 6-pin DIPs. On the 8003 model, up to sixty 16-pin DIPs, or any combination of devices, can be attached using solder or wire- wrap. Each Circbord costs S9.95. Contact Vector Electronic Com- pany, 1 2460 Gladstone Ave, Syl- mar CA 9 1 342, (2 1 3) 365-966 1 . Circle 545 on inquiry card. 16 K-Byte ROM from OKI OKI Semiconductor Inc has in- troduced an NMOS (n-type metal- oxide semiconductor), 128 K-bit ROM (read-only memory). The MSM-38 1 28 is organized as 1 6 K bytes by 8 bits. It has a 450 ns maximum access time, operates off a single + 5 V supply, and features a 120 mA supply cur- rent in the operating mode and 20 mA current in standby. Com- patible with the 128 K-bit 2364 ROM from Intel, the MSM 38 1 28 features power-down state and is nonclocked. All inputs and out- puts are TTL (transistor-transistor logic) compatible. For information, contact the the company at 1 333 Lawrence Expy, Suite 401, Santa Clara CA 95051, (408) 984-4842. Circle 546 on inquiry card. 450 September 1981 © BYTE Publications Inc THE STAR MODEM From Livermore Data Systems RS232 MODEM IEEE 488 MODEM RS232 CCITT IEEE 488 CCITT SALE $128 SALE $199 $170 $280 STAR Modem is the price performance leader with a t 2 YEAR FACTORY WARRANTY. We carry Apple 11+ from Bell & Howell PROGRAM YOUR OWN EPHOMS Bunding Iron for PET/CBM $79 EPROM Projnmnur with software for all ROM ver- sions. Includes ill necessary hardwire and software to program or copy 2716 and 2532 EPROMS. Paper-Mate Word Processor $39.95 PET/CBM full featured 60 command system by Michael Riley. Uses either tape or disk and any printer. Includes in- text commands, tloating cursor, scrolling, etc. FlexhfTlTiMi Base for CBM/PET $60 Random file handling system with Report Writer and Mail Label Handler. By Michael Riley. REVERSAL (Spracklen) 32K Apple 28.00 Super FORTH 48K Apple 40.00 Energy Miser for PET, Apple, or Zenith 24.50 Data Manager (Lutus) 24 K Apple 40.00 Histo-Graph (Boyd) 48K Apple 24.50 Data-Graph (Boyd) 48K Apple 40.00 Apple II User's Guide (Osborne) 12.00 Introduction to Pascal (Sybex) 10.30 Pascal Handbook (Sybex) 12.00 Graphics Cookbook for Apple 9.90 Musical Applications of Micros (Chamberlin) 20.00 Basic FORTRAN (Coan) 7.25 KM MM Pascal for PET $75 Subset ol standard Pascal with true machine language translator for faster execution. 16K with tape or disk. EARL for PET (disk file based) $65 Editor, Assembler, Relocator, Linker to generate relocat- able object code. FORTH for PET/CBM or Apple $65 A full-featured FORTH with extensions conforming to Forth Interest Group standards. Includes assembler, string pro- cessing capabilities, disk virtual memory multiple dimen- sioned arrays, floating point and integer processing. MIPLOT Intelligent Plotter by Watanabe Instruments (Digiplot) SPECIAL $1195 Has all intelligent functions for producing graphs and drawings including i vector and 4 character commands Solid and broken lines can be specified. Character gen- erator for alpha, numeric, and symbols. Characters 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 EPSON MX-80 Printer 475 EPSON MX-80 F/T Printer 575 EPSON MX-70 Printer 380 EPSON MX-100 Printer 770 Centronics 739 Printer 750 STARWRITER Daisy Wheel Printer 1445 Leedex Video 100 12" Monitor 129 ZENITH DATA SYSTEMS Z19 Video Terminal 729 Z89 with 48K 2150 Extra 16K RAM 115 Z-47 Dual 8" Drive 2775 SYM-1 209 SYM BAS-1 BASIC or RAE-1/2 Assembler 85 KTM-2/80 Synertek Video Board 349 6502 6502A 6520 PIA 6522 VIA 6532 7.45 8.40 5.15 6.45 7.90 2114-L200 ns RAM 2114-L300 ns RAM 2716 EPROM 2532 EPROM 4116 200ns S-100 Wire Wrap Zero Insertion Force 24 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 25/3.50 100/3.25 3.15 25/2.90 100/2.65 7.75 5/7.45 10/6.90 17.00 8 lor $20 2.65 pin Socket $2.00 «« CASSETTES - AGFA PE-61 1 PREMIUM High output, low noise, 5 screw housing, labels. C-10 10/5.65 50/25.00 100/48.00 C-30 10/7.30 50/34.00 100/66.00 All other lengths available. Write for price list. commodore CBM-PET SPECIALS o Up to $375 tree merchandise I £V *lth purchase of one ol following CBM-PET Items: 8032 32K - 80 Column CRT 8050 Dual Disk Drive 4016 Full Size Graphics Keyboard 4032 Full Size Graphics Keyboard 8096 96K - 80 Column CRT 2040/4040 Dual Disk Drive - 340K 4022 Tractor Feed Printer CBM Voice Synthesizer C2N External Cassette Deck Used CBM/PET Computers VIC Personal Computer WRITE FOR SYSTEM PRICES DISK SPECIALS SCOTCH (3M) 5W 10/2.85 50/2.75 100/2.65 SCOTCH (3M) 8" 10/2.90 50/2.80 100/2.70 Verbatim 5V 10/2.45 50/2.40 100/2.35 (add 1 .00 for 5W' Verbatim plastic storage box) Verbatim8"Dbl.Dens. 10/3.45 50/3.35 100/3.25 BASF 5'A" 10/2.40 20/2.35 100/2.30 WRITE for prices on WABASH Disks WE STOCK MAXELL DISKS 1295 260 795 140 395 50 95 12 CALL 300 25 Diskette Storage Pages Disk Library Cases 8" - 2.85 10 for 3.95 5" -2.15 A ATARI 800 $745 All Atari Modules 20% OFF *** EDUCATIONAL DISCOUNTS *** Buy 2 PET/CBM Computers, receive 1 FREE WordPro 3+ - 32K CBM, disk, printer 250 WordPro 4+ - 8032, disk, printer 335 OZZ Data Base System for CBM 8032 335 VISICALC for PET or ATARI 170 SM-KIT - Super PET ROM Utllltites 40 ATARI EDUCATIONAL PLAN — r A P Products 15% OFF A P Hobby-Blox 15% OFF Write fer details. 4 PART HARMONY MUSIC SYSTEM for PET The Visible Music Monitor, by Frank Levinson, allows you to easily enter, display, edit and play 4 part harmony music. Includes whole notes thru 64ths(with dotted and triplets), tempo change, key signature, transpose, etc. The KL-4M unit includes D to A converter and amplifier (add your own speaker). KL-4M Music Beard with VMM Pniorsm S 59.90 Programmers Toolkit - PET ROM Utilities 34.90 PET Spacemaker II ROM Switch 36.00 2 Meter PET to IEEE or IEEE to IEEE Cable 40.00 Dust Cover for PET 6.90 IEEE-Parallel Printer Interface for PET 1 10.00 IEEE-RS232 Printer Interface for PET 120.00 The PET Revealed 17.00 Library of PET Subroutines 1 7.00 Source Hookup over 1 000 programs/services The 8086 Book (Osborne) Z8000 Assembly Language Programming PET Personal Computer Guide (Osborne) PET and the IEEE-488 Bus (Osborne) 6502 Assembly Language (Osborne) Programming the 6502 (Zaks) 6502 Applications Book (Zaks) 6502 Software Cookbook (Scelbi) CP/M Handbook (w/ MP/M) Zaks Practical BASIC Programs (Osborne) Some Common BASIC Programs (Osborne) 252 Bethlehem Pike Colmar, PA 18915 215-822-7727 A B Computers 88 WRITE FOR CATALOG. AddSt 25 per order for shipping We pay balance of UPS surface charges on all prepaid orders Prices listed are on cash discount basis Regular prices slightly higher Circle 4 on inquiry card. BYTE September 1981 451 ™'™Heath Users Double Your 5V," disk storage capacity without adding a drive. Get twice as much from your H88 or H89 microcomputer. Our FDC-880H floppy disk controller, in conjunction with your 5V," drives, for example, expands memory capacity from 256 bytes to 512 bytes per sector. And it handles single and double- sided, single and double-density, 8" and 5 1 /," drives — simultaneously. Call 714/275-1272 today or write for details. m C.D.R. Systems Inc. Controlled Data Recording Systems. Inc. 7667 Vickers St., San Diego, CA 92111 ONE BOARD CP/M SYSTEM! only $750 Assm., Tested & Burned-In for one week Features: • 8'/s by 12 inches • 10 MHZ 8085 CPU • 64K RAM ■ 3 RS-232 channels • 8272 Floppy Disk Controller • Handles Single/Double Density • One to Four Drives. 801 R or 850R. Documentation S15. CP/M Floppy Disk Operating System S150 Check or Money Order (autocontroll ^*\ 11744 Westline Industrial Drive 1 St. Louis. MO 63141 1 (314)432-1313 ^J AC-85CP/M® SYSTEM Assm., Tested & Burned In for one week $2450 Features: • One board 8085 Computer • 2 - SA800R* (1.2 megabytes) • CBIOS Diskette • Installed and wired in a cabinet with P/S and Fan ready to plug-in • Manual • 17'/i" Wx 17" Dl 10" H » SYSTEM with 2 SA850R (2.4 mbytes) $2750.00 CP/M Floppy Disk Operating System $150 Check or Money Order autocontroll 11744 Westline Industrial Drive St. Louis, MO 63141 (314) 432-1313 ® CP/M is a registered trademark of Digital Research, Inc. Circle 55 on inquiry card. Circle 32 on inquiry card. Circle 33 on inquiry card. Scotch* DISKETTES SAVE 40% XS&SSZ 5%"Sgl. Dens. 26.70/10 Specify soft, 1 or 1 6 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 ATARI OWNERS Parallel Printer Interface for the ATARI 800 connects 1o controller jacks 3 and 4 works with BASIC/DOS/ASSEMBLER FOUR printer connectors available: TRENDOCM 100/200 A8P-1 ATARI 825/CENTRONICS 730/737 . . A8P-2 EPSON MX-80/MX-70 6 other 36 pin- A8P-3 'Fits all other parallel Centronics plus Okidata, Anadex, Base 2 Microtek, etc. I.D.S. PAPER TIGER 440/445 ... A8P-4 $69.95 CA sales tax order by pari number M.C./VISA accepted GRAPHICS PRINTING SOFT WARE & ATARI 400 printer interlaces also available © To order toll free 1 800-344-7493 In CA call 12091 667-2888 /VL4CROTRONICS, inc. . {Qfi WANTED: APPLE, PET, TRS-80, CP/M SOFTWARE Westico is a publisher and distributor of professional software for microcomputers. If you have a new program ready for distribution or want your existing programs to reach a larger market, contact Phillip Woellhof, V.P. Mktg. Westico, Inc. 25 Van Zant Street Norwalk, CT 06855 (203) 853-6880 To increase your profits, take advantage of Westico's worldwide promotion and distribution. WESTICO The Software Express Service Circle 196 on Inquiry card. Circle 197 on inquiry card. CONTROLS SINGLE BOARD Z-80A* COMPUTER FOR CONTROL USES ai Test Equipment Intelligent Ponpno.ai Comr Solar Healing & Power Sy: Appliance Control FEATURES: J MHZ Z-80A- ion DoatO ctystal,. Ik HAM, sockois tot 2 2N6's (4K PROM I. 3-B O.I parallel TTL output pons. 2-fl tut parallel TTL input potts. 8 analog input pom (100 (isec conversion lime), 6 nigh cutienl output linos (open collector). 4 opto- isolated input f.nes. e*»a sing.'o nil TTL oulput lot senal IfO, 2-80 coniiol lines Dioughl to odgo connector, eitra port decodes brought to edge connector. I input port doubles as buslorporlo0 9 95 MM5330 5 94 PQ4HD-3 4 00 PD411D-4 5 00 P5I01. 8 95 42Q0A 9 95 82S2S 2 90 91L02A 1 SO HD0ia-5 G95 MM57100 4 50 GIAY3850D 1 9 95 MCMG6751A 9 95 9368 KEYBOARDS SG hey ASCII leyDoam Ml Fully assimDiea 53 ney ASCII keyBoaiO hit Fully Bstmr ■■■■ : t Plastic IC SOCKETS Solder Tin Low Prollli PIN 1 UP PIN 1UP WIRE WRAP LEVEL 3 Mela! Enclosun 29 95 S10D 1000 16 67 2B 1 00 CLOCKS MM53H 5 5i MM5312 3 9 MM5314 3 9i MM5359 2 H MM5841 14 4 MM5855 7 9 CT7010 8 9 CT7015 8 9 MM5375AA-N 3 9 MM5375AGN 4 9 720S 16 5: 7207 7 5. 720B 15 9 7209 4 9 DS0026CN 3 7 DS0056CN 3 7 MM53104 2 5' Z 45 MICROPROCESSOR 2 35 6502 10 95 1 10 6504 9 95 3 00 6522 9 95 35 6530 9 SO 2 MHj 4 50 4 MH* 4 25 5 MHz A 25 10 MHz 4 25 18 MHz 3 90 20 MHz 3 90 32 MHz 3 90 32766 Hz 4 00 1 5.132 MHz 4 50 3 5795 MHz 1 20 2 0100 MHz 1 95 .- [)97lb2MH: 4 3Q ? 4b76 MHz 4 50 ■; 2768 MHf 4 50 :, imv :w! 4 50 <> 16!: MHz 4 50 5 7143 MHz 4 50 "i'il 6S536M!lz 4 50 tit 14 31B18MIIZ 4 25 IS, 18 432 MHz 4 SO Hi 22 1184 MHz 4 50 11 95 KEYBOARD ENCODERS -"95 AY5-2376 S12 50 5 95 AV5-3600 17 95 3 95 AV5-9100 10 50 12 95 AY5-9200 16.50 9 95 74C922 5.50 11 95 74C923 5.50 2 90 HD0165-5 6 95 LEDS Red T018 15 Green. Yellow T01B 20 JumrjQ Rn1 20 Green. Orange Yellow Jumoo 25 CliplMe LED MounllnD Clips 8 51 25 ISDeofyred. jttito green, yellow clean CONTINENTAL SPECIALTIES in suck Corn [,lete Mis u' Mf jilDoj-Cles! i-SjiU MAX-100 8 dign Fieq. Ctr. 1149 ■)■■ Complete line olAP Products in stock. Swllches Minn Pushbutton 3 pos slide Eniodei iirjf)i65-5 Piralionict Model >0 Trigger {■pjrider Kil S2; MCCEI 150 Bui deck Cilcnflar Kit S: 1.1 MHz Frequency Counler Kll t 30 MHz Frequency Counter Kll & TRANSFORMERS 6V 300 m.i 12 Voir 2 a'tip -*j.ll plus 12 6 CT 2 amp 12 OCT 4 amp 12 6 CT 8 amp 12 BVCT 600 ma 12V 250 ma wall plug 12'/ CT 250 ma wall plug 24V Ct 100 ma 10/ 1 2 amp wan plug 1?/ 6 amp 12'/ 500 mav.au plug /vl'ilCN ;vm;-xn 75444CN 450 22 00 8700CJ 8701CN B750CJ 13 9b LD130 9 95 9J00CJWF 7 43 ICL7103 9 53 ICL7107 14 25 CMOS C04000 CO40O1 C04002 CD400S CO4O07 i n.i.ioa i.n.'.fm CD40TC C 1)4011 CD4012 CD4Q13 CD4014 CD4QI5 CD40I6 CD40W CD4Qt8 CD401O CO4020 CO4021 C04Q22 CD4023 CO4024 B228 4 95 8251 6 95 8253 15 00 8255 5 75 8257 10 95 8259 14 95 1802CP plas 13 95 i802CPpias 17 95 1B61P 9 50 CDP1B02CD 28 95 CDP1802D 35 00 CDP1816P 7 95 UART/FIFO AY5-1313 AY510H Connectors RS232 DB25P I DB25S I □E9S DAisp ; DA15S Complete Set 12V 1 I pwfl 9 SO 10 IS VAC B 16 VA wan plug 9 75 DISPLAY LEDS MANI CA 270 2 90 MAN3 CC 125 39 Man;? 74 CA CA 300 I 00 DL704 CC 300 l 25 DL7Q7 0L707R CA 300 1 GO HickokS'iDioitLEDmul' limeler 89.95 Slopwalch Kil Auto Clock Kll Digital Clock Kll 26.95 17.95 19.75 DL727 72B D1747 750 FN0359 JND5U0 507 FND503 510 FNDB00 8"" 3di iSubb ST09 8H0 8T13 3120 BT23 3T24 8T25 8T26 8T2B 2101 I PROM 1702A 4 50 2532 19 75 2708 4 70 2716T1 8 50 2716 5VOII 6 50 8/2716 5 Volt 48.00 2732 210M 2102AL-4 2IQ2AN-2L 2104A.J 21Q7B-4 2758 874 1 A 8748 8748-B 8755A N82S23 NB25123 f;£2Si36 NB2SI29 N82S131 •JS-313^ •JS2S'j7 Df/.B577 ' B223 55 00 HK-ifiK Eprom Kit (less PROMSl 5B9.00 Motherboard S3 9 00 Eilender Board $15 DO RESISTORS ■. wall 5'. 10 per type 03 25 per lypc 025 UJO per [ype 015 U"'00 ;n- type 0'2 350 piece pack 5 pei type 6 75 ': watt 5'.. per type 05 DIP Switches 4 'positions 95 7-posihon 1 S-position 1 00 8-pOSilrcn 1 6-position 1 00 CA CC 500 t 90 CA CC 600 1 95 CC 357 70 CC CA 500 l 35 CC CA 500 90 CC CA BOO 2 20 80 1 25 MAN354fl CC 30 1 10 MAN4&I0 CA 4Q j 20 MAH4540 CC 40 I 20 MAN4710 CA 40 95 MAtj474Q CC 40 I 20 MAM840 CC 56 2 95 MAN6710 CA 60 1 35 MAN6740 CC 60 1 35 MA1002A. C. E 8.95 MAIOUA i 95 102P3 liintlormer 2-25 MA1012A Transloimer 2.25 4116 200ns Dynamic RAM 8/S18.40 PROM Eraser assembled. 25 PROM capacity $37.50 (with timer 569.50). 6 PROM capacity OSHA/ UL version $78.50 (with timer $108.50). Z80 Microcomputer 16 bit I/O, 2 MHz clock, 2K RAM, ROM Bread- board space. Excellent for control. Bare Board $28.50. Full Kit $99.00. Monitor $20.00. Power Supply Kit $35.00. Tiny Basic $30.00 S-100 Computer Boards 8K Static Godbout Econo HA 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 $161.00 Color Video Kit 129.95 81 IC Update Master ManualS79. 95 Comp. IC data selector, 2 vol. master reference guide. Over 51 .000 cross references. Free update service through 1981. Domestic postage $4.75. 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 $17.00. Article in June Radio Electronics. Gremlin Color Video Kit $69.95 32 x 16 alpha/numerics and graphics; up to 8 colors with 6847 chip; 1K RAM at EOOO. Plugs into Super Elf 44 pin bus. No high res. graphics. On board RF Modulator Kit $4.95 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. $9.95 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 frequency 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 instruc. Multi-volt Computer Power Supply 8v 5 amp. r18v .5 amp. 5v 1.5 amp. -5v .5 amp, 12v .5 amp, -12v option. =5v. +12v are regulated. Basic Kit $35.95. Kit with chassis and all hardware $51.95. Add $5, 00 shipping. Kit of hardware $16.00. 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 Elf for so little money. The Super Elf 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 mode and 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. A 24 key HEX keyboard includes 16 HEX keys 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 1 27 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 R&D. Remember, other computers only offer Super Elf features at additional cost or not at all. Compare before you buy. Super Elf 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. Free 14 page brochure. of complete Super Elf system. Moews Video Graphics $3.50. Games and Music $3.00, Chip 8 Interpreter $5.50. 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 of low power RAM fully address- able anywhere in 64K with built-in memory pro- tect and a cassette interlace. 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 ±.17E 3a ), 32 bit integer ±2 billion; multi dim arrays, string arrays; string manipulation; cas- sette I/O; save and load, basic, data and ma- chine language programs; and over 75 state- ments, functions and operations. 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 full 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-100 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 interface board. Parallel I/O Ports $9.65, 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). 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. Type-N-Talk by Votrax Text to speech synthesizer with unlim- ited vocabulary, built-in text to speech algorithm, 70 to 100 bits per second speech synthesizer, RS232C interface $345.00. 1802 16K Dynamic RAM Kit $149.00 Expandable to 64K . Hidden refresh w/clocks up to 4 MHz w,no wait states. Addl. 16K RAM $25.00 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 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, Z80 etc. Dealers: Send' for excellent pricing/margin program. Editor Assembler $25.00 (Requires minimum of 4K for 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. Calif residents add 6% tax. 110.00 mln. BankAmerlcard and Master Charge accepted. $1.00 insurance optional. Postage: Add 5%. CO.O. $10.00 min. order. FREE: Send lor your copy of our NEW 1981 QUEST CATALOG. Include 48c stamp. Circle 308 on inquiry card. BYTE September 1981 455 NEW 16K-RAM PERSONAL COMPUTER $00000 FACTORY SALE C.C.<3 PRICE For $229™ you get the new Interact Model "R" Computer, 16K-RAM, 2K-R0M, 8080A Microprocessor, color, sound, full 53 keyboard, high speed cassette, AC adapter, R.F. Modulator, Black Console Case, 90 days parts and labor warranty, owners' guide, FCC approved. 15 DAY FREE TRIAL Return within 15 days complete and undamaged for refund of purchase price. PROTECTO ENTERPRIZES BOX 550, BARRINGTON, IL 60010 PHONE 312/382-5244 TO ORDER MULTIBUS for SALE: SBC86/12A $1200 SBC 80/30 $ 450 SBC 064 $ 900 SBC 604 $ 85 SBC 614 $ 85 BLC556 $ 175 Much more in stock. We buy/swap/ sell any/all computer systems. Add 2% for shipping/handling. Oracle Electronics & Trading Co., Inc. 467 Hamilton Ave., Suite 22 Palo Alto, CA 94301 (415) 321-7650 RS-232 PROBLEMS? LET THE RS-232 TESTER HELP YOU SOLVE YOUR COMPUTER INTERFACE PROBLEMS. DESIGNED TO CONNECT IN SERIES WITH ANY RS-232 INTER- FACE, IT DISPLAYS THE STATUS OF SEVEN OF THE MOST IMPORTANT LINES: TRANSMIT DATA, RECEIVE DATA, REQUEST TO SEND, CLEAR TO SEND, DATA SET READY, CARRIER DETECT, AND DATA TERMINAL READY. THE RS-232 TESTER RE- QUIRES NO POWER AND MAY BE LEFT IN THE LINE PERMANENTLY. $39.95 POST PAID B & B ELECTRONICS BOX 475/MENDOTA, IL 61342 Circle 301 on Inquiry card. Circle 133 on Inquiry card. Circle 35 on Inquiry card. Sr n rem auRijTy camPonErvrs l_U Q & R 48 HOUR BOARD EXCHANGE WARRANTY ON GODBOUT 6 SYSTEMS GROUP COMPUTERS A tested duplicate beard will be sent via UPS BLUE LABEL Service for one year. GODBOUT Systems include DMA CPU,64K-10MHz Ram (expandable to 512K) DMA Disk 1 Con- troller, 2 serial ports, IEEE S-100 Single Unit 12 Slot Mainframe & Dual 8" Drive Cab with (2) Shugart SOlR's (One Megabyte) CPU Z 6MHz Z80 System w/CPM*2.2 3995. CPU 6MHz 8088/8085 System w/CPM*2.2 4095. CBASIC 86 275. PASCAL M 86 225. SYSTEMS GROUP 2B00 Series COMPUTERS with 4MHz Z80,64K Ram, 2 serial & 2 par. ports CPM* System (2) Shugart 801R's 1MB 3995. CPM* System (2) NEC 1160's 2MB 4695. CPM* System 1 NEC 1 Hard Disk 10MB 7095. MPM* System 2 NEC 1160's 128K 2MB 5584. CPC2811 4MHz Z80 365. FDC2801 Disk 343. Word Star 300. DBASEII A.T. 585. Godbout 6MHz Z80 308. Disk 1 DMA AST 386. Epson MX80 par 473. Shipping Extra WE BEAT ANY BONAFIDE PRICE ON TELEVTDEO SYSTEM I, II, OR III . Call for price Q,T. SYSTEM+I 64K, (2)801R's Z80A 2995. TELEVTDEO 910,912,920, & 950 Best Prices ALL PRICES & SPECS, SUBJECT TO CHANGE CPM* is Registered r.M. of Digital Research *pd aax. qsi ^Mut 'l^ESTrhinSTEF? CR q5b"feJi2 • "714 ^D^S |-|Hfc3 ISIS <— > CP/M® Full bi-directional file transfer capabilities are provided in the ISIS-CP/M utilities package. Written in machine language and running under CP/M, these utilities permit the CP/M user to read or write files direct to/from an ISIS Diskette. They will run under any version of CP/M without re- gard to diskette density. The complete package is $250.00 including user's man- ual. Write for free brochure on other CP/M software. SOUTHERN COMPUTER SYSTEMS, INC. P.O. Box 3373A Birmingham, AL 35255 (205)933-1659 Serial Printer Interface (RS232C) lor L APPLE II" only "179 i assembled' tesled burned in/ docum • Powerful ON BOARD SOFTWARE provides -TOP OF FORM & AUTO PAGING -LIST formal lor program listings (inserts I or 2 blank lines after any user specified program line) -"HARD COPY" reproduces screen text on printer -INPUT from printers with keyboards • 32 DIP SWITCH levers select ALL printer interface parameters (columns/line lines'page vertical margins and more) •BAUD rates between 70 and 1500 • Output functions selected via ATTRACTIVE color coded CONTROL PANEL Hits under keyboard) •Control panel and 7 ft printer cable included ORDER NOW or send for MORE INFORMATION RADIX, Inc. JCO residents add 3°° sales lax P O Box 3465 Foreign orders add 10% Littleton CO 80161 MC VISA COD MO 1303) 985-4152 Personal Check ladd 3 wks) ■ registeied trademark of Apple Computer Inc Circle 329 on Inquiry card. Circle 333 on inquiry card. Circle 315 on inquiry card. 68KFORTH New SYSTEMS LANGUAGE for ERG 68-696 CPU and Motorola's KDM boarc. 0/S, Compiler, Monitor, Assembler, Interpreter, Virtual Memory, Screen Editor, DBL Precision Arithmetic and more. FORTH-79 Standard Vocabu- lary. $795 Empirical Research Group, Inc. POBox 1176 Milton, WA 98354 206-631-4855 IC-IRS will Find It ICIRS $37.50 1980CMDB $29.95 IC-IRS by siand Cybernetics Is THE Information Retrieval Syatam for Indexing and retrieving entries with large amounts ol FREE FORM TEXT, such as ABSTRACTS; CORRESPONDENCE FILES (with complete letters); At- torney's CASE NOTES, CONTRACTS, WILLS; MD'S and Scientist's JOURNAL ARTICLES; or any other similar type of Information. EASY TO USE. COMPUTERIZE your CARD FILES or MAIL LISTS. IC-IRS runs as a ".com" lile on CP/M* compatible systems with 2 disk drives and 32K memory. IC-IRS Is written In CONVERS for fast execution. It searches the 984 entry 1980 COMPUTER MAGAZINE ARTICLE DATA BASE In 25 seconds using combinations ol KEY WORDS with up to 65 "and"s and 32 "or"s. Get IC-IRS and the 1980 COMPUTER MAGAZINE ARTI- CLE DATA BASE (1980 CMDB) on standard 8"SD disks or 5 1/4" disks In several popular formats. IC-IRS 2.07 with manual = $37.50 + $2.50 postage. 1980 CMDB = $29.95 (no postage with IC-IRS) Call (512) 2S8-S310 and use your MASTERCARD or VISA, use the bingo card or write to: FYI, INC. P. O. Box 10998 #615 Austin, Texas 78766 CP/M is a registered irademark ol Digital Research LOWEST POSSIBLE PRICES BEST POSSIBLE WARRANTY model III 16K fisaasa^agCT 5 color computer 4K $310 call TOLL FREE 1-BOO-343-8 124 rmnnuter 245A Great Road ***l"'»*V^a Littleton. MA 01460 plus* Write for yout IJ1UO 617 -486 -3193 free catalog. Circle 139 on inquiry card. Circle 146 on Inquiry card. Circle 77 on Inquiry card. Ml CROPROCESSOi R SUPPORT /.( :/s WE GUARANTEE FACTORY PRIME PARTS 2716 EPROM 1-9 10& IID 2708 EPROM 3 SUPPLY 2732 EPROM 1-9 10& HITACHI INTEL MOTOROLA +5 7.00 6.00 +5 9.50 8.00 +5 7.00 6.00 AMERICAN MICRO DEVICES AM2708DC 1-24 25-99 100&UP INTEL MITSUBISHI NEC UP 17.00 16.00 | 16.00 15.00 16.00 15.00 NATIONAL +5 7.00 6.00 3.50 3.20 2.90 Tl 3 Supply 7.50 6.00 16K x 1 DYNAMIC RAM 21 14L STATIC RAM 74LS SPECIAL NEC UPD 1-31 2.50 32-99 2.30 416C-2 200NS 100-499 2.10 500 & UP 1.90 31- 100 1Kx4 1-31 99 &UP HITACHI 200NS 2.85 2.60 2.35 INTEL 200NS 3.00 2.85 2.70 NEC 250NS 3.00 2.85 2.70 LS175 LS240 LS241 LS244 LS245 LS373 .75 1.15 1.15 1.00 1.95 1.15 Z80-P10 6.00 8755 49.95 4050 .69 4531 .99 74C925 6.95 74LS107 .45 74LS244 1.00 Z80A-P10 7.10 4000 .35 4051 1.10 4532 1.25 74LS0O .35 74LS109 .45 74LS245 1.95 Z80-CTC 6.00 4001 .35 4052 1.10 4539 .99 74LS01 .28 74LS112 .49 74LS247 1.10 Z80ACTC 7.10 4002 .35 4053 1.10 4543 1.99 74LS02 .28 74LS122 .55 74LS248 1.10 Z80-DMA 18.50 4006 1 .39 4055 3.95 4553 3.50 74LS03 .28 74LS123 1.19 74LS249 1.69 Z80A-DMA 22.50 4007 .29 4056 2.95 4555 .75 74LS04 .39 74LS125 1.35 74LS251 1.79 Z80-S10/0 18.50 4008 1 .39 4059 9.95 4556 .75 74LS05 .28 74LS126 .89 74LS253 .98 Z80A-S10/0 22.50 4009 .49 4060 1.39 4581 1.99 74LS08 .39 74LS132 .79 74LS257 .98 Z80-S10/1 18.50 4010 .49 4066 .75 4582 1.01 74LS09 .39 74LS136 .59 74LS258 .98 Z80A-S10/1 22.50 4011 .35 4068 .35 4584 .55 74LS10 .28 74LS138 .89 74LS259 2.95 Z80-S10/2 18.50 4012 .29 4069 .35 4585 .99 74LS11 .39 74LS139 .89 74LS260 .69 Z80A-S1 0/2 22.50 4013 .49 4070 .49 4702 9.95 74LS12 .39 74LS145 1.25 74LS261 2.49 3205 3.95 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 .3B 74LS156 .99 74LS283 1.10 8202 45.00 4019 .49 4078 .35 74C14 1.65 74LS22 .38 74LS157 .99 74LS290 1.29 8205 3.95 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 I 8216 1.85 4023 .38 4086 .79 74C42 1.85 74LS30 .26 74LS162 .98 74LS324 1.75 I 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 I 8251A 5.55 4029 1.29 4503 .69 74C90 1.85 74LS48 .79 74LS173 .89 74LS365 .99 I 8253 9.85 4030 .45 4505 8.95 74C93 1.85 74LS51 .26 74LS174 .99 74LS366 .99 I 8255A 5.40 4031 3.25 4506 .75 74C95 1.85 74LS54 .35 74LS175 .75 74LS367 .73 I 8255A-5 5.40 4032 2.15 4507 .95 74C107 1.19 74LS55 .35 74LS181 2.20 74LS368 .73 I 8257 9.25 4033 2.15 4508 3.95 74C151 2.49 74LS73 .45 74LS190 1.15 74LS373 115 I 8257 5 9.25 4034 3.25 4510 1.39 74C154 3.50 74LS74 .59 74LS191 1.15 74LS374 2.75 I 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 I 8279 10.80 4041 1.25 4515 3.95 74C163 2.39 74LS83 .99 74LS195 .95 74LS386 .65 I 8279-5 10.80 4042 .95 4516 1.69 74C164 2.39 74LS85 1.19 74LS196 .89 74LS390 1.95 1 8282 6.70 4043 .85 4519 .99 74C173 2.59 74LS86 .45 74LS197 .89 74LS393 1.95 1 8283 6.70 4044 .85 4520 1.39 74C174 2.75 74LS90 .75 74LS221 1.49 74LS395 1.70 1 8284 5.85 4046 1.75 4522 .99 74C175 2.75 74LS92 .75 74LS240 .1.15 74LS399 2.95 I 8286 6.70 4047 1.25 4526 1.15 74C192 2.39 74LS93 .75 74LS241 1.15 74LS424 2.95 1 8287 6.70 4048 .99 4527 1.75 74C193 2.39 74LS95 .88 74LS242 1.95 74LS668 1.75 1 8288 25.40 4049 .69 4528 .99 74C195 2.39 74LS96 .98 74LS243 1.95 74LS670 2.29 1 8289 49.95 INCH MINIMUM ORDER $10.00 JDE $3.00 FOR U.P.S. GROUND HANLEY ENGINEERING I (206) 643-0792 I 1 3400 NORTH UP WAY #22 BELLEVUE, WASHINGTON 98005 $4.00 1 Wash r OR UPS BLUE or 1 st CLASS MAIL ington State Add 5.4% Sales Tax FOR T HE FINEST IN MICROPROCESSOR SUPPOR1 r i.e. 1 s Circle 156 on inquiry card. BYTE September 1981 457 6809 Small C Compiler ■ Generates assembly language source output ■ Requires only 16K memory ■ Library functions in source code ■ Generates position independent code ■ Supports most C functions ■ Generates ROMmable code INTRODUCTORY PRICE $75 specify 5 or 8 inch diskette SSB or FLEX TERMS: Check or Money Order. California residents add 6%. C.O.D. orders add S3. 50 shipping & handling. DOGGER'S GnOWinGBlSVSTEffV POST OFFICE BOX 305 SOLANA BEACH.CA 92075 714-755-4373 Available soon: Basic to C Converter LABELS 15/16"x3*4" 1 up - pin feed white pressure sensitive PRICE INCLUDES SHIPPING Packed 5M per box - Min. order 1 box -S14.75 Check with order - Mass Residents add 5% Sales Tax CHECK-MATE P.O. Box 103, Randolph, MA 02368 Telephone: 617-963-7694 PROFESSIONAL MICROCOMPUTER THE BEST VALUE ON THE MARKET • Z80 4MHZ • 54K RAM • DUAL 8" DRIVES • 1.2 MB STORAGE • 2 SERIAL I/O • 2 PARALLEL I/O • OPERATING SYSTEM AND UTILITIES MICRO BUSINESS ASSOCIATES. INC. 500 SECOND STREET SAN FRANCISCO. CA 94107 415-957-1343 Circle 126 on inquiry card. Circle 58 on Inquiry card. Circle 217 on Inquiry card. DATAP0INT 1134 Diskette Sy items 1 6k Processor with Four Diskettes (1 Megabyte). 80 CPS Matrix Printer. Nationwide maintenance available. $2,645 SOFTWARE AVAILABLE DISK OPERATING SYSTEM SORT UTILITY ISAM UTILITY ALSO AVAILABLE FOR 5250 EACH. A/P. A/R, GENERAL LEDGER, PAYROLL, TIME ACCOUNTING, AND INVENTORY AMERICAN COMPUTER EXCHANGE 100 N. MAIN ST. BOX 52 CHAGRIN FALLS, OH 44022 216-247-2100 DIGITAL PROPORTIONAL CONTROLLER 7 BIT TTL/CMOS INPUT OPTICAL ISOLATION INTERFACE COMPUTERS TO MOTORS, HEATERS, LAMPS 120 VAC 240 VAC 15 AMP Q§ 3715 WHITSELL AVE. PALO ALTO, CA 94306 (415) 493-0779 BIBLIOTEK The Bibliographic Management System • Includes journals, books and symposia (patents, technical reports, government documents available soon!) • A minimum of 500 references per bibliography • Rapid citation entry through multi-page video forms • Search by authors, titles, editors, dates and/or keywords • User defined output formats • Requires 48K Apple II, ROM Applesoft & two drives • $300.00 Scientific Software Products 3171 Donald A Indianapolis, lis. ... (317) 286-0467 IN residents add 4% tax p •Apple II and Appiesoli are l Dealer inquiries welcome ol Apple Computer Co.. Inc Qc Accepted Circle 19 on inquiry card. Circle 98 on inquiry card. Circle 320 on Inquiry card. FULL PERFORMANCE CP/M* computer $1995 list SI dealer-distributor discounts \ Afspa Computer, Inc. 5215 Scotts Valley Drive Scotts Valley, CA 95066 (408) 438-3326 "trademarks of Digital Research, Inc. FREE! 1981 DISCOUNT ELECTRONICS CATALOG JOIN THE PAK! Send for our Free catalog and become a exciting catalog seven times a year. We offer Penny Sales, Free Premiums and Lo 53 Low Prices on a wide variety of Electronic Products such as Computer Periph- erals, integrated Circuits, Speakers, Audio Equipment, Rechargeabf - " ucls, Semiconductors, and much, much more! Take advantage ol our 25 years as America's foremost Supplier of discount electronics. POLY PAKS, INC. P.O. BOX 942, BT9 VSAYNNFIELD, MA. 01940 i PEX MEW! interface Converts Your Typewriter into Printer • Finest print quality *Lowcost ■ Easy Installation • Quick delivery • FIE IBM SELECTRIC* typewriter with no modification. • For TRS-80*, Apple*, or any parallel or RS232 port. • write or phone for more Information, todayl — U.S. and worldwide sales — INTERNATIONAL INC. 16140 valerlo St. Van Nuys, CA 91406 USA TEL 213/781-0020 TLX/TWX: 910-495-1767 iPEX Circle 15 on Inquiry card. Circle 294 on Inquiry card. Circle 176 on inquiry card. WE WILL NOT BE UNDERSOLD DISK DRIVES FOR TRS-80* Model I CCI-100 5 1 /.", 40 Track (102K) $299 ADDON DRIVES FOR ZENITH Z-89 CCI-189 5 VI", 40 Track (102K) $394 Z-87 Dual 5 1 /i" system $995 External card edge and power supply included. 90 day warranty/one year on power supply. RAW DRIVES 5V4"TEACorTANDON $CALL POWER SUPPLIES $CALL DISKETTES - box of 10 5'/." Maxell $40 8" Maxell $45 PLASTIC FILE BOX-Holds 50 5V«" diskettes PLASTIC LIBRARY CASE 5 1 /i" $3.00 HEAD CLEANING DISKETTE FLOPPY SAVER $11.95 16K RAM KITS 200ns for TRS-80,*Apple II, (specify): SYSTEM SPECIAL Apple II Plus 48K w/drive and controller. Epson MX-80 printer and interface. SUP-R Mod RF Modulator: List $2965 You Pay $2299 BASF/Verbatim BASF/ Verbatim RINGS 2 for $37 Jumpers $26.95 $36.00 $19.00 $ 4.00 $25.00 $ 6.95 $19 $2.50 COMPUTERS/TERMINALS ARCHIVES 64K, 2-Drives, 77 Track ALTOS ACS8000 Series ZENITH 48K, all-in-one computer ZENITH Z-19 TELEVIDEO 910 $559 920C $ 729 IBM 3101 Display Terminal ATARI 400 $ 429 MATTEL INTELLIVISION APPLE PERIPHERALS 950 800 $CALL $CALL $2200 $ 725 $1039 $1189 $ 795 $ 259 $CALL S-100 CALIFORNIA COMPUTER SYSTEMS MAINFRAME Model 2200A Z80 CPU Model 2810 MOTHERBOARD Model 2501 16K STATIC RAM, 200ns Model 2116C 32K STATIC RAM, 200ns Model 2032C 64K DYNAMIC RAM Model 2065C FLOPPY DISC CONTROLLER Model 2422A EXTENDER BOARD Model 2520K 2P + 2SI/0 Model 2718A $349 $259 $106 $309 $619 $580 $345 $ 52 $309 PRINTERS NEC SPINWRITER Letter Quality High Speed Printer R.O. R.O. with tractor feed KSR with tractor feed NEC SPINWRITER 3500 Series, 5 new models EPSON MX-70 MX-80 MX-80FT PAPER TIGER Graphics &2K buffer Graphics & 2k buffer Graphics MX100 IDS 445 IDS 460 IDS 560 ANADEX OKIDATA Microline 80 Microline 80 Microline 82 Microline 83 CENTRONICS C. ITOH Starwriter I Starwriter I Starwriter II Starwriter II DP-8000 $849 Friction & pin feed Friction, and pin & tractor feed Friction & pin feed feed 120 cps, uses up to 15" paper 739, new model with graphics 25 cps, parallel interface 25 cps, serial interface 45 cps, parallel interface 45 cps, serial interface DP-9500/01 PRINTER SPECIAL SEIKOSHA GP-80M MONITORS BELL& HOWELL LEEDEX List $399 $2395 $2555 $2795 $CALL $CALL $ 695 $ 799 $ 999 $1295 $ 415 $ 500 $ 615 $ 849 $ 749 $1449 $1529 $1829 $1949 You Pay $319 9' 12' 13" 9' 12' 13" B&W BHD911 B&W $129 Color B&W B&W Color $329 $149 $219 $349 SANYO ZENITH TELECOMMUNICATIONS LIVERMORE STAR MODEM 2-year guarantee UNIVERSAL DATA SYSTEMS UDS-103 D-CAT HARD WIRED DIRECT MODEM AUTO-CAT Auto Answer, Direct Connect Modem APPLE-CAT II D.C. HAYES MICRO-MODEM D.C. HAYES SMART-MODEM CCI Telnet Communications Package $195 12" Green Screen $159 12" Green Screen $238 13" Color $406 12" Green Screen $129 $125 $179 $189 $249 $349 $295 $235 $135 APPLE ACCESSORIES AND SOFTWARE VISICALC $155.00 DB MASTER $159.00 Z-80SOFTCARD VIDEX BOARD KEYBOARD ENHANCER 16KCARD APPLE JOYSTICK SUP-R MOD CCS CARDS GALAXIAN SPACE ALBUM ASTEROIDS FLIGHT SIMULATOR WIZARDS PRINCESS SARGON2 MYSTERY HOUSE $ 24.00 HIRES FOOTBALL $259.00 $259.00 $110.00 $169.00 $ 49.00 $ 25.00 $CALL $ 22.95 35.00 17.95 29.00 28.00 $ 29.00 $ 35.00 For fast delivery, send certified checks, money orders or call to arrange direct bank wire transfers. Personal or company checks require two to three weeks to clear. All prices are mail order only and are subject to change without notice. Call for shipping charges. dealer (national/international) inquiries invited Send for FREE Catalogue TO ORDER CALL TOLL FREE 1-800 -343 -6522 TWX: 710-348-1796 Massachusetts Residents call 617/242-3361 The CPU SHOP 5 Dexter Row, Dept. B09M Charlestown, Massachusetts 02129 Hours 10AM-6PM (EST) Mon.-Fri. (Sat. till 5) Technical Information call 617/242-3361 Massachusetts Residents add 5% Sales Tax Tandy Corporation Trademark/" Digital Research Circle 96 on inquiry card. database manager forms 80 Model I • CREATE random access disk files 15 fields or 255 bytes/record Files can span 4 disk drives Password protected file access • Database DIRECTORY displays all user files and their attributes • Powerful TRAI\ISACTIONS-add, edit, read, delete & list records Efficient binary tree sorts • Sophisticated QUERY with multi- key relational & logical operations • REPORT formatter requires only for user to select desired fields Automatic sub & grand totals May be used with lower case • Entirely MEIMU DRIVEN operation • Extensive error trapping routines • User oriented instruction manual • Requires 32k — 2 disk drives Introductory price $59.95 Visa and MasterCard accepted mentor software 816 McLane Aue-Morgantown, VW 26505 Tandy Corp. Trademark Circle 212 on inquiry card. EAGLES ? COWBOYS ? RAIDERS RAMS II you'd like lo know NOW. before the big game Wilh PHOCAP and your TflS-80*. you can use slatislics and probability theory io predict the results ol this week's big games And more. PROCAP • Gives offensive and defensive ratings for every National Football League team ■ Predicts range ol results and probable score (or each game • Allows computer matchup ol any iwo teams (Great lor playoffs 1 ) • Gives up-lo-lhe-minute standings, statistics, and ratings lor each NFL Division PHOCAP is easy lo use and comes with extensive documentation fliy S49 95 number NOW Money bat Dial (800) 543-3000. operator 400 In Ohio dial (800) 582-1364. operator 400 The Trinity Computer Group • Software Agent /Publisher PRIAM Disk Subsystems and Accessories, (SMD interface available) lowest cost and greatest established relia- bility for H.P., DEC, Apple, Z-80, 8085 ... and so on. We can show you how to overcome "foreign disk" warranty worries. Special Opportunity: 14A. S-100 Power Supply Kit Input: 95-220VAC, 50/60 Hz * ~ A Outputs: 14A@±8VDC $£u 2A@±18VDC Includes: UL Spec. Transformer, Rectifiers, Computer Grade Capacitors. RFI line filter, and Schematics. ADVANCED TECHNOLOGY 735 Loma Verde, Palo Alto, CA 94303 415-493-5930 Send 36 ct SASE for our 16 page flyer. Circle 10 on inquiry card. CP/M® Compatible $GOLD DISKS Z-80 Software Z-80 Disassembler Jk | 7S ppd c r eates assembly language source files E-ZText $75. ppd unique text file word processor Bower-Stewart Si Associates POST OFFICE BOX 1389 HAWTHORNE, CALIFORNIA 90250 213/676-5055 Trademark Digital Research *********************** "COMPUTER SURPLUS** *********************** Brand new Perkin-Elmer No. 550 terminals —priced ridiculously low. Call us for a quote. CALL VICTOR CLOUGH (216)473-0866 Also buy scrap computer systems, printed circuit boards, connectors etc. ... LARGE VOLUME ACCEPTABLE DATA HARDWARE 701 Beta Dr. #4 Cleveland Ohio 44143 DEALERS WELCOME Circle 101 on inquiry card. ARE WE CRAZY? K0!, WE ARE KL0F0X, the people that bring to you a system with so many features, it could sell for twice as much (like some of our competitors do). We believe high qual- ity need not have a high price, and our systems prove iti For just 1695.00, you'll get a Z-80 system with 6Uk of RAM, and up to 8k of bank-selected PROM, The two bidirectional parallel ports let you interface to almost anything. The basic system is equipped with one SD 8" disk drive, but can easily be expanded to four giving one megabyte of on-line storage. You will have a choice between an 80x2*4 terminal simulating video interface, or two serial ports, or even both (at an extra charge). Our systems will run GP/M and MP/M, and we include our custom BIOS and XI0S, plus many other useful system utilities. KJ.OFOX PO BOX 93 SAN LUIS OBISPO, CA 93406 USA (805) 52S-7440 Note: CP/M and MP/M are both trademarks of Digital Research of Pacific Grove, CA Circle 366 on inquiry card. Circle 43 on inquiry card. Circle 185 on Inquiry card. FACTORY PRIME STATIC RAM CHIPS 2114 Super Low Power 200ns. 1Kx4 $ 2.90 6514 CMOS 300ns. 1Kx4 $ 6.90 6116 CMOS 200ns. 2Kx8 $22.50 Add $5.00 Handling on Orders Under $200.00 FfiPTflRY PRIMP From ,fie same shipments usecl m rMl/IUni rnimt GIMIX Professional quality boards. 32KB STATIC RAM CARDS for the SS50 and SS50C BUS (16KB - $298.12), (24KB - 348.14) (32KB — $398.15) .jeW- 64KB BATTERY BACK UP N CMOS RAM CARDS Two independently addressable 32KB blocks, each with extended addressing. (56KB ■ $994.56), (64KB - $1088.64) 2MHZ 6BD9 56KB SS50 SYSTEMS $2498.29 DISK SYSTEMS AVAILABLE Gimix (5i 1337 W. 37th Place • Chicago, IL 60609 (312)927-5510 • TWX 910-221-4055 The Company that delivers. Quality Electronic products since 1975. GIMIX* and GHOST* ate Registered Trademarks el GIMIX INC. 1802 fig- FORTH high-level compiler language 10- 20X faster than BASIC ELF II /Super ELF /Other w/assembler-editor $60 w/macro assemb. screen-editor $80 extras on cassette/requires 12k+RAM P.O. Box flu.-ttn. T. 78712 -312-477-22B7 EVERY BUY, SELL OR TRADE ALL TYPES OF COMPUTER EQUIPMENT AND SOFT- WARE (pre-owned and new) among 20,000 readers nationwide in BIG (11x14") pages. Classified ads are only 10* per word and are indexed for easy and fast location. Subscription: $10 a year / 12 issues. Money back guarantee. Sample copy, $1.50. CamPUTSR SHOPPSR P.O. Box F-14 Titusville, FL 32780 (305) 269-3211 MasterCard or VISA subscription orders only, call TOLL FREE 1-800-327-9920 Circle 149 on inquiry card. Circle 145 on inquiry card. Circle 78 on inquiry card. sC SONAL OMPUTER 3000 Family 14 display, hi-res color sr and lower case t popular in Japan ures compare with Apple III '01A CPU V 32K RAM osoft Basic Doard: Numeric pad, er programmable keys parallel, one serial port 12A I/O RAM, expandable to 128K it bus expansion 31A Mini-Disks ves, 143K per drive \fl C-8001A $1295 PC-8012A $795 3031A . . . $1295 n Discount $3200 Authorized Dealer QT STEM H+ r* SYSTEM H + and SYSTEM* Byte hard disk lz Z-80A, 4 serial, 2 parallel Ram useable per user A multi-user DOS up: 1 MByte floppy : Optional tape cartridge $12,750 Call 13,250 lor 13,750 quotes 14.250 QT SYSTEM+ HZ Z-80A, 2 serial, 2 parallel tloppies, double density Ram. EPROM monitor for RS-232 vl 2.2 onal 6. 8, or 12 slot motherboard anal single or double-sided floppie: led in— just add video terminal ;S(6) .. iS(8) .. )S(12) . , $3595 SYS+DS(6) $4495 . . 3695 SYS+DS(8) 4595 ..3795 SYS*DS(12) 4695 QT MINI- YSTEM+ f5fc ve with BJ4" floppies MINI-SYSTEM* (5'/,") +SS(6) $2495 MSYS*DS(6j . . . $2795 *SS(8) 2595 MSYS+DS(8) .... 2895 ♦SS(12) 2695 MSYS+DS(12) . . . 2995 QT RAM+16 16K Static, S-100 < switchable RAM jsands of happy customers $35 4MHzKit...$180 4MHz A&T . . $165 - V DISK Y. CKAGES 88-2 2-801 R. cab., ps, fan $1250 88-22 2-Qume DT-8. cab., ps. fan 1675 88-3 Cabinet, ps. fan, cables 325 88-4 Cabinet only 58 irt801R $390 DT-8 585 i-51 250 i-52 350 QT SBC+2/4 00 Single Board Computer iA. 2 or 4 MHz. switch Ham. 1 parallel, 1 serial tOM monitor (specify) A, programmable timers . $195 A&T . . . $300 STARWRITER • Daisywheel printer. Diablo compatible • Nationwide service • Centronics parallel or RS-232 serial • 25 cps or 45 cps. specify 25-P $1400 25-S $1500 45-P 1750 45-S 1850 Tractor . . $200 EPSON MX-100 • Wide carriage • Friction, tractor, graphics • "Correspondence" quality print Unbeatable price $795 SEALS IS BACK Seals 64K Static S-100 • Uses Fujitsu MB8167. 16K + 1 static in 20 pin • 70ns: DMA to 14MHz • Complete 16 bit or 8 bit flexibility • IEEE S-100 and Cromix compatible List $1195 Now S1050 STATIC MEMORY SYSTEMS 64K Static S-100 • See ad, this issue • Intermix RAM and EPROM • 200ns, very low power SMS-64K A&T $550 QT Z+80 CPU • 2 or 4 MHz. switch • Monitor with jump • Serial port to 9600 baud Kit . . . $165 A&T . . . $225 QT EXPANDABLE + REV II S-100 64K Dynamic RAM • 2 or 4 MHz. switch • Bank switch, IEEE Standard • On board refresh, 4 layer PC • Burned in, tested. EXP +16 $270 EXP • 48 S310 EXP + 32 290 EXP + 64 330 (Less $40— kit) QT I/O+ S-100 4 Parallel, 2 Serial • On board crystal • Prog, baud • 16 prog, timers • 8 level prog, interrupt Brd . . . $70 Kit . . . $235 A&T . . . $375 QT SILENCE+ S-100 Motherboards • Full ground shield network • Specify board, kit. or assembled 6-B . 6-K 6-A . 18-B $50 22-B 18-K 100 22-K . 18-A 140 22-A . $25 8-B $27 12-B. ..40 S-K 55 12-K. . .50 8-A 70 12-A. $30 . 70 . 90 $75 140 190 QT MAINFRAMES • 18A power supply, S-100 • Drive power supply • Specify motherboard slots • Specify 8", 5V." or no floppy 2-8" Floppy w/motherboard MF8-6 $625 MF8-8 650 MF8-12 e75 2-5%" Floppy— w/Motherboard MF5-6 $450 MF5-12 500 No Floppy— w/Motherboard MF*12 $450 MF+18 500 MF*22 600 8 QT SINGLE ' CABINET m • Accepts one 8" floppy • Power supply, tan. AC filter • 117v AC/220V AC • Data cable, power cables DDC+8 $1 75 SD SYSTEMS 20%+ Discount on ^3 A&T All SD items available. 38007 Z-80 Starter Board $424 38013 VDB-8024 (60 Hz) 444 38020 Expandoram II-16K 310 38023 Expandoram II-64K 370 38025 PROM 100 248 38059 Versafloppy II (RS-232) 400 38060 Versafloppy II (VDB-8024) 400 38061 SBC-200 (VDB-8024) 376 38062 SBC-200 (RS-232) 376 Call tor kit, software, and cable prices. CALIFORNIA tmm COMPUTER SYSTEMS \fm m 15% Discount fc— J All CCS items available. ^^^^ S-100 2032A 32K Static -2 MHz $561 2032B 32K Static - 4 MHz 641 2116A 16K Static - 2 MHz 297 21 16B 16K Static - 4 MHz 331 2200A Mainframe 368 2210A System 1600 2422A Floppy Controller 360 2710A 4-Port Serial 289 APPLE 71 14A 12K ROM/PROM Board $68 7440A Programmable Timer 97 7470A A/D Converter 102 7490A QPIB IEEE-488 255 7500A Wire Wrap Board 20 7510A Solder Tail Board 21 7520A Extender Board 25 7710A Serial Asynch Board 136 7728A Centronics Parallel Bd 105 781 1 B Arith Processor - disk 355 781 1 C Arith Processor - ROM 355 NEC SPINWRITER 55CPS • Receive only, serial interface Only $2500 IDS PAPER TIGERS #445 $710 K460G 1050 «560G 1300 TELETEK FDC-1 Single Board Computer $685 FDC-2 Double Density Controller 325 QT S-100 EXTENDER • With connector Kit S30 A&T S35 CABLES RS-232- male/male - 9 ft $24.00 RS-232 - male/male - 1 8 ft 29.00 RS-232 - male/female - 9 ft 29.00 ^ ADDS VIEWPOINT <& Smart CRT Terminal • 80 x 24 • Detachable keyboard The Best for Less $625 QT S-100 CARD CAGES • 6. 8 or 12 slot • Accepts Silence * mothei • With card guides • Accepts 4" fan • Specify with mother, with fan 6 Slot (5V.wx 10»d x 6"h) CC+6 $24 CC+6M 90 CC+6M/F 115 8 Slot (7'/.w x 10V4d x 6"h) CC»8 $39 CC+8M 99 CC+8M/F 134 12 Slot (11VSW x 10%d x 6"h) CC+12 $61 CC+12M 114 CC+12M/F 149 \M ADES S-100 HARD DISK • PRIAM 3350 8" Winchester • 31 MByte with CP/M 2.2 • With S-100 controller • Cables, cabinet, power supply • Full line available »S33 List $5195 Now 2 MBYTE ~~-- FLOPPY FOR HJ|_ APPLE - - B^-=i ISiiil, • 2 double density, double sided 8" drives • Cabinet, power supply, cable, controller • DOS 3.3 compatible (Pascal and CP/M optional) • This package is best, spec (or spec; price tor price. Suggested List . . . $2550 Now Only $2050 SAVE $500 CP/M Patch $75 Pascal Patch $75 ADD-ON DRIVE FOR APPLE • Works with Apple disk controller • Functionally identical to Apple • Expandable to 40 track Prairie Fire Price $375 BULK DISKETTES • Single side, double density • Specify hard, soft, U of sectors • Sold in hundreds 5W $215/100 8" Library cases: 5%" $25/10 8" .... .$275/100 $32/10 ANTI-STATIC CHAIR MAT • 4'x5' black, hard • With ground strap • New religion— thousands of believers List $185 Special $160 QT CLOCK/CALENDAR+ Apple, S-100, TRS-80 (Specify) • Date, month, year • Day of week, leap year • 24 hour or AM-PM • 4 interrupt intervals • With software • Now with on-bowd battery S-100/Apple/TRS $150 Floppy- Data: Card Edge r r .1 I _**_« Type SD • Jade DSC-34-1 DSC-34-2 DSC-34-4 DSC-50-1 DSC-50-2 DSC-50-4 Single, mini $24.00 Dual. Mini 29.00 Quad. Mini 34.00 Single, 8" 24.00 Dual, 8" 32.00 Quad. 8" 40.00 Floppy-Data: Pin Type CCS • Tarbell • Teletek DSP-34-1 Single, Mini $24.00 DSP-34-2 Dual. Mini 29.00 DSP-34-4 Quad, Mini 34.00 DSP-50-1 Single, 8" 24.00 DSP-50-2 Dual, 8" 29.00 DSP-50-4 Quad. 8" 34.00 8" Floppy-DC Power PDC-8 24" long $7.00 INTEGRATED CIRCUITS 4116 (200ns) .... $2.00 2114 (450ns| 2.00 2708 3.50 2716 (5V) ..' 6.50 2716 (5-12V) 8.00 2732 13.00 4164 (200ns) .... 25.00 Z-80A 12.95 8080A 3.50 8085A 20.00 8086-4 60.00 TMS9900 29.95 8212 3.50 8214 4.50 8228 6.00 8238 6.00 8251 7.00 8257 17.95 8295 16.50 MC14411 11.00 14411Xtal 4.95 1771B01 24.95 1791 A01 37.95 S2350 7.95 N8T26 2.50 1488 1.25 1489 1.25 D3242 10.15 TMS5501 19.00 TR1602B 4.50 6845P 22.00 4118 18.95 DP8304BN 4.00 is a trademark of Apple Computer. Inc CP/M and MP/M are trademarks of Digital Research TRS-80 is a trademark of Radio Shack. PRODUCTS MAIL ORDER: PO Box Q, Sherman Oaks, CA 91423 Circle 39 on inquiry card. RETAIL: 15620 S. Inglewood Ave., Lawndale, California 90260 (213) 970-1476 (800) 421-5150 % Block South of San Deigo Fwy. TERMS OF SALE: Cash, checks, credit cards, C.O.D. Calif, residents add 6% sales tax. FULL ELIZA FOR YOUR MICRO! AT LAST! A FULL IMPLEMENTATION orlhe original ELIZA program is now available to fun on your microcomputer' Created al MIT in 1966, ELIZA has Become Ihe a noiKJfreolfvI psychottW3p!a4 IKhC analyses each staleiienl as you type il in and then responds with ner own comment or question. Response time is virtually inslanlaneousand her remarks are ollen startlmgly appropriate. Designed lorun on 3 large maintrame. ELIZA has hiihcrlo been unavailable to small computer users c $1250.00 - / Plus— Sales Tan S Plus — Shipping I nventory Mailing Address- This sale terminates when this ad closes. Act Now. * PACIFIC DISCOUNT SOFTWARE 3204-A Production Avenue Oceanside, California 92054 Telephone (714)439-6201 Circle 28 on Inquiry card. Circle 252 on inquiry card. Circle 276 on inquiry card. CROMEMCO USERS PMSI INTRODUCES ICIAL nif'OHTlNG SY5UM BANKKEEPING * REPORTER FOR - Offers Current Cash Flow Analysis and Complei SMALL Profit/Loss Picture for Each Month and BUSINESS Year-To-Date Adaptable to All Types of Business, Farms. Property Management and Investments FDR Provides a Unique Budget tor F3m.ly INDIVIDUALS Expenditures for Current Month and Year To [ Supp'ies a Monthly Recap of Tax Deductible Items as Well as Complete Listing of All Tax Deductible Items for the Entire Y Perfect Package for CPA's. Bookkeeping Seruic Service Bureaus. Banks and Savings/Loans PMSi PROVIDES S ■ ftGI i PRACTICAL MANAGEMENT SYSTEMS. INC P O BOX 1301. 2900 KING STREET JONESBORO. AR 72401 501 932 8206 -DEALER DISCOUNTS AVAILABLE- A ATARI' Atari 80016K 810.00 16K RAM 85.00 Atari 800 48K 950.00 Atari 850 Interlace 176.00 Atari 810 Disk 460.00 Atari 830 Modem 1 56.00 Atari 400 16K 379.00 Microsoft Basic 72.00 TELECOMMUNICATIONS PACKAGES Base Unit, A850, A830, TeleLink I with 800: $1 1 50.00 with 400: $71 0.00 PLUS FREE NOVATION SUPERMIKE! The Bit Bucket is a company made up of com- puter professionals. We are able to provide low prices as well as technical support. Give us a call and find out why we consider the Atari the best home computer on the market today. You won't be disappointed. The Bit Bucket Specializing in Atari Home Computers P.O. Box 365 Newton Highlands. MA 02161 (617)783-3144 FORTH FOR/MAT™ SCREEN EDITOR A MUST FOR THE SERIOUS FORTH PROGRAMMER • All code is Forth-79 standard. Each line of code is fully explained and flow-charted (Forth style) for easy modification. • This editor works just like the popular word processors on the market except it is written in high level forth and is confined to the 1024 byte boundary of a forth screen. • There are over 20 different commands for cursor positioning, text modification, tabs, relocating lines, spreading lines, and moving lines to other screens. • Insert mode is toggled on and off for midstream insertions and deletions. Text ahead of C Pis moved right during insertion and left during deletion if insert mode is on. ■ Column position is displayed at ali times. • Bomb proof — all unused control codes are trapped • Must be used with a CRT that has cursor addressing or with a memory mapped video. • Send check or money order in the amount of $50.00 and receive complete source code, flowcharts, documentation, and instructions for bringing up on your system. KV33 CORPORATION P.O. BOX 27246 TUCSON, AZ 85726 (602) 889-5722 W Circle 298 on Inquiry card. Circle 40 on Inquiry card. Circle 186 on Inquiry card. EPSON DOT MATRIX PRINTERS SUPER DISCOUNTS ON MX-80F/T L0 ^f Rl NOW IN LOWER! LOWER! O I UUK MX-80 MX- 100 We also stock direct connect cables for TRS-80, Apple, Atari, Pet or RS 232 CALL TOLL FREE 1 -800-344-7493 In CA and for service (209) 667-2888 © AMCROTRONICS. inc. . il ll?b N Golden Stole Bvd ItillaCli CoMorrwa 95380 Heath/Zenith 89 Users I6K MEMORY EXPANSION CARD a to make a H/Z89 a 64K machine. Assembled and Tested $100.00 COMPUTER TABLES 60x28x28 $186.40 48 x 28 x 28 $162.40 Shelves Available PRINTER STAND $75.00 MS ■amp*** 'Mint I data systems AUTHORIZED SERVICE CENTER SECURED COMPUTER SYSTEMS 1201 I Aclare St. • Cerritos, CA 90701 (2 1 3) 924-674 1 Shipping not included ANALOG** DIGITAL DIGITAL** ANALOG CONVERSION MODULES SOFTWARE CAIN CONTROL BTliTaftlAnWl'" amplifier - custom board test S-100 - y to lb hhz able high and low inputs gain 1 1 to 1024 IS bii ■■■ imple and hold amplifiei annel diff efentiol 16-channcl - onalog to digital high accuracy programmable gain instrumentation amplifier custom boorrj i.-,i - S 100 - 2 to 15 khz conversion time - maoblB htgh and loui inputs - gain frum 1 ■ I05M 12-bit sample and hold amplifier 8-channel differential - 16-chcvinel - onalog to digital high accuracy programmable n.am mstrumsntotioi nmnlihrr ciatofn board tcsl S-100 - " io IS kh. For additional derails about trie AD-100-4 and other fine California Data Corporation 100% individually tested, high reliability products, circle the reader service card number below or for faster response write or call us. CALIFORNIA DATA CORPORATION 3475 Old Conejo Road, Suite C-10 Newbury Park, CA 91320 (805) 498-3651 Circle 198 on Inquiry card. Circle 326 on Inquiry card. Circle 50 on inquiry card. DEALS □ DEALS U DEALS 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! • • • • D C TO w s? MICRO I VI. HP. SALES 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 I+24V @ 7A | US-384 89.00 SHUGART-SIEMANS-MPI 5%" +5V@.5A + 12V@.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 +24V@3A US-206 69.00 +5V@3A -5V@.6A +24V @ 5A US-162 89.00 +5V@ 1.7A -5V@l.5A +24V 9 2A US-272 69.00 +5V@2A + 12V@.4A -12V(9>.4A US-HTAA 37.50 TELEVIDEO 950 Televideo 950 -$950.00 Talevideo 912C- 665.00 Televideo 920C- 720.00 ADDS R-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" 5%" 5%" 8" 8" 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. w 11 EDISON DRIVE • NEW LENOX * ILLINOIS 60451 CALL TOLL FREE: 1-800-435-9357 * MONDAY thru SATURDAY (ILLINOIS RESIDENTS CALL: 815-485-4002) * 8:00 a.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) $189.00 m^^i 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, inch, less fans) DUAL DRIVE SUBSYSTEM $995.00 $195.00 w/no Drives ' 1V&, ; . .:_][ If this looks like a Lobo Drive System, don't be fooled. Just because it 2 SHUGART 801 R 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 tool $145.00 Kit (Less Cable) 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. mm iti 1 1 ii it '|Bi $375.00 Very Special Price on -»-»»wbww these BRAND NEW current production units Add $10.00 for Extended 1 Year Warrantee! Circle 369 on inquiry card. OAE's PP-Series EPROM Programmers plug directly into any vacant EPROM socket and allow you to transfer data directly from RAM to EPROMs. No additional power supplies are required. All timing & control sequences are handled by the programmer. Each unit in- cludes internal DC to DC switching regulator, ZIF socket and 4 ft. ribbon cable terminated with a 24 pin plug. Programmers are available for all EPROMs from 2708's thru 2532's. Oliver Advanced Engineering, Inc. 676 W. Wilson Ave.. Glendale, CA 91203 (213) 240-0080 or Telex 194773. PP SERIES PROGRAMMERS See us at NCC, booth 770 68000 ERG68-696 68000 CPU available and in produc- tion. Meets or exceeds all aspects of IEEE696 S-100 standard. $1995 Z-80 emulation teg rated 68000 also available. and in- systems Empirical Research Group, Inc. P0 Box 1176 Milton, WA 98354 206-631-4855 WRITE YOUR OWN COMPILERS IN PL/C PL/C (Programming Language/Compilers) is the implementation of a BNF superset as a high-level programming language. Our Z80 version runs on a 32K CP/M™system and generates TDL-format assembler code. The PL/C Compiler, Runtime Library, and Compiler Source Code are shipped on an IBM-3740 format, CP/M compatible diskette. A license agreement must be completed. Lifetime single-CPU license fees are as follows: $1000 — PL/C Compiler, Runtime Library, Compiler PL/C Source, and PL/C Source Code for a PL/C Compiler Version which pro- duces PROCESSOR-INDEPEN- DENT macro source. $5000 — As above, plus commented Assem- bler Source Code for the Compiler and Runtime Library. A PL/C information package is available for $25 MRD Systems, Inc. Box 147, Spring Valley, MN 55975 CP/M is a registered trademark of Digital Research Circle 262 on inquiry card. Circle 140 on Inquiry card. Convert your TRS-80 into a DEVELOPMENT SYSTEM Z-80 In-Circuit emulation and EPROM/EEPROM programming in a single compact unit. Debug stand-alone systems with program in TRS-80 RAM, then copy working program into PROM. Only $329 including personality module for2716, 2516, 2758, 2508, 2532, 2816, 2808,48016. ORION INSTRUMENTS 172 Otis Ave, Woodside, CA 94062 (415)851-1172 Circle 271 on inquiry card. RUN BIG CPM* PROGRAMS ON YOUR MODEL 1 TRS-80* WITH 39orS4Kof usespace.Can use Mixed Drivers 5'A or 8" (Variable Tracks) Compatable with all TRS*80 Operating Systems and all TRS*80 Programs.(usable on 48K disk systems only) Boards fit into keyboard inclosure. FREEDOM OPTION $245 MEMORY EXPANSION OPTION. . . . $295 Send Check or Money Order to: (MASS RESIDENTS. PLEASE INCLUDE SX TAX) F-E.C. ltd. P.O.Box 2388 • Woburn, MA. 01888 (017)944-5329 ;i!:^ : ^::: wabash When it comes to Flexible Disks, nobody does it better than Wabash. MasterCard, Visa Accepted. Call Free: (800)235-4137 PACIFIC EXCHANGES 100 Foothill Blvd San Luis Obispo. CA 93401 (In Cal call (805)543-1037) Circle 279 on Inquiry card. r~ QUARTZ CRYSTALS **$ 1 , .32188 52428 8 99336-8 20 000-B 3628B6-B 428518-B 4681288 , \ 1 53904 5610 8 9.984088 20.4988-I 363636-8 428768-8 473768-8 ' l , ' 1 000 A 5.7143 B 9.989608 22.1184-1 375628-8 4282588 4788388 1 , 1.8432 A 59SSB I0O0OB 22825&E 3837688 4256288 48800 B , * 1 1 84378 59828 102458 -B 263556-E 3S.4448B 4300084 4830068 | 1 ' 2 000 A LUBM 1049688 26.5006 f 3882588 430378-8 486668 8 < . 1 2JN71 A 61448 10.77558 268706-E 3882588 430748-8 48.7006-8 { 1 . 7 4576 » 6.15030 a 108255-3 278008 39.3128 B 431858 8 48.87688 . 1 1 2.500 A 6.297808 1 083868 27JW06E 39 5038 a 43.25988 49 7006-B ' , 1 ' 266578 MOM II 1360 B 276506 E 39.66688 433338-8 49.73388 1 » 299508 6.55368 11.1558 2B.4006E 39.7538B 43.3708-B 4981288 . ' 1 , 3 000-A 6.72630 B 11.2186-8 2B8276-E 398768-B 43.4078-B 5025058 | | 3.067B 6.75840-8 11.28908 2B.7536E 39.BB28B 43.43788 5185568 ' , . 1 3,200-8 690038 II4776-B 298758-E 40.4448-B 43.44488 51.31288 ( ' | 32768 A 7.0063 8 II 6566 6 298378 E 403928-8 43.555B-B 51.777B-B . 1 * . 3.5008 7.03366 11.68168 30H64BG 40.81211 tl 43.62988 5185068 ' , , ' 3.5798 7.09168 12.440-8 30 3606 -t 408336-B 43.6668-B 52.8I2B8 < . 1 4-00Q 4.6103 8 B 1416 B I5S066-B 318008-1 41.1666 8 43.888BB 70.4006-B , ' 1 465038 B IBIS 8 16 000-B 320008 41.3768-8 43.92588 75D0058 | i 1 4B303B 833038 16 3648 B 33.2006! 4I537BB 44.00088 9083388 ' I 49152 B 8.49988 17.22488 33.6258-E 42OOOB0 4403788 99S66B-8 ( 1 . 5.000 B 857668 172422 8 34.5558 8 4258368 44.37688 1006668 8 . * 5 0688 8 B.60568 18.0008 34.7538! 42.62688 44.7778 B 101.46688 ' , ' 5 1203 B 8.9608-8 18.4320-8 34.9776-E 42.70068 451256 8 1030668-8 < | 5.1850 8 B99068 19.4690-B 355256-1 42.7538 B 46.3X68 103.4668 8 i 1 . 5 1856 8 9.472088 19 75088 36.000-8 42.81488 46.70068 104 9918 8 , 1 All * - seas All 8 - 1159 OOHMflriF OF-HUCT 5" ' ADD SI. OO SHIPPING CAL. RES. ADD 6% SALES TAX FREE OSCILLATOR SCHEMATICS WITH ANY ORDER 1 ' QUALITY COMPUTER PARTS ! I 1 P.O. BOX 743 / CHATSWORTH , CA 91311 | Agfa? Loaded and Cassette Boxes for Software Producers & Duplicators Ask lor our Catalog POly 312/298-5300 1233 Rand Road • Des Plaines IL 60016 UPS ANYWHERE IN CONTINENTAL U.S. © UHF VABACTOB-TUNER. Channels 14-83, tunable. 1/0 = 75 ohms. Power Gain = 10-20 dB$23 max. Complete with schematic and tech data. Brand new - surplus. ® NICAD 5 AA BATTERY PACK in shrink tube SCgs with solder tabs. Brand new - surplus O © CABLE TV CONVERTER. For conversion to mid- Conor; band and superband cable stations. Brand new*04 ! ' 3 and its LEGAL! © BBAND NAME POWER SUPPLIES ±5V/6A. «mmHB Voltage adjustable and IC regulated. Ideal for'23 CMOS, computer-based instruments, etc. use. Brand new - surplus © MODULATOR. Video and sound input with 75 S-i egs ohms output. Switchable to channels 3 or 4. ID Shielded case. Brand new - surplus. SCR ELECTRONICS INC. [7141 527-2554 9533 VALLEY VIEW, CYPRESS, CA 90630 Pay by CHECK, M.O., VISA, MIC, C.O.D. Circle 304 on Inquiry card. Circle 295 on Inquiry card. Circle 324 on Inquiry card. COMPUTER STOP 2545 W. 237 St. Torrance, CA. 90505 ORDER BY PHONE MON.— SAT. 10-6 (213) 539-7670 PST TELEX: 678401 TAB IRIN LOWEST PRICES IN THE WEST.NORTH. SOUTH & EAST McippUz computer 1-800-421-1947 A ^=^Kw Sales and Service ^ ^m APPLE /// OPTION A: 3850 .^flH^k. ^ ^^^^ APPLE /// 96K Information Analyst Package 12" B/W Monitor APPLE /// OPTION B: 4350 SAME AS OPTION A PLUS: DISK II for APPLE/// APPLE/// OPTION C: 4800 SAME AS OPTION A PLUS: DISK II FOR APPLE/// SILENTYPE Thermal Printer APPLE HARDWARE Parallel Printer Interface Card 160 Communications Card 195 High Speed Serial Interface 160 Pascal Language System 425 Centronics Printer Interface 185 Applesoft Firmware Card 160 Integer Firmware Card 160 Disk ][ with Controller DOS 3.3 529 Disk ][ only 475 Graphics Tablet 625 OTHER HARDWARE Alf Music Synthesizer (3 Voice) 245 9 voice 175 ABT Numeric Keypad 119 Micromodem ][ 295 Apple Clock 245 Rom Plus with Keyboard Filter 175 lntrol/X-10 System 250 Romwriter 150 DoubleVlslon 80 x 24 Video Interface 245 CCS Arithmetic Processor 399 CCS Parallel Interface 119 16K Ram Card 145 Microworks DS-65 Digisector 339 SVA8inch Disk Controller 335 Sup-R-Mod 30 CCS Synchronous Serial Interface 119 CCS Asynchronous Serial Interface 99 Corvus 10 Meg. Hard Disk 4395 Corvus Constellation 595 MISCELLANEOUS/SUPPLIES 16K RAM (200-250 NS) 29 Verbatium Datalife Diskette (Box of 10) 30 Dysan Diskettes (Box of 5) 22 Apple Diskettes (Box of 10) 45 Verbatim Diskette Boxes (Holds 50 Disks) 18 Silentype Paper (Box of 10 rolls) 40 APPLE ][ Plus 16K $1075 48K $1193 Disk][Drive . . $529 with Controller & Dos. 3.3 PASCAL SYSTEM $425 Z-80 Softcard $299 MONITORS/DISPLAYS Leedex Video 100 12" 140 Sanyo 9" Monitor 195 KG-12C Green Phos. Monitor 275 Sanyo 12" Green Phosphor. Monitor 275 NEC 12" Green Phosphor. Monitor 275 Sanyo 12" B/W Monitor 250 PRINTERS Apple Silentype with Interface 525 IDS 445 (Paper Tiger) with Graphics 650 IDS 460 with Graphics 1049 IDS 560 with Graphics 10) 1199 Centronics 737 795 NEC Spinwriter (RO, Serial) 2650 SOFTWARE The Controller 525 Apple Post (Mailing List Program) 40 Easywriter Professional System 195 Apple Pie 2.0 95 DB Master Data Management 175 The Cashier 210 Apple Writer 65 Vlslcalc 170 CCA Data Management System 90 Full Screen Mapping for CCA DMS 59 Pascal Interactive Terminal Software (PITS) 29 Basic Interactive Terminal Software (BITS) 29 Data Capture 29 Data Factory DMS 110 Apple Plot 55 Apple Pilot 120 Magic Wand Word Processor (Needs Z-80 Softcard) 345 Dow Jones Portfolio Evaluator 45 Fortran 140 ORDERING INFORMATION: Phone orders invited using VISA, MASTERCARD or bank wire transfers. VISA & MC credit card service charge ot 2%. Mail order may send charge card number (include expiration date), cashier's check, money order or personal check (allow 10 business days to clear.) Please include a telephone number with all orders. Foreign orders (excluding Military PO's) add 10% for shipping. All funds must be In U.S. dollars (letters of credit permitted). Shipping, Handling and in- surance in U.S. add 3% (minimum $4.00). California residents add 6% sales tax. Our low margins prohibit us to send COD or on purchase orders or open account (please send for written quotation). All equipment Is subject to price change and availability. Equipment is new and complete with the manufacturer warranty. We do not guarantee merchantibility of products sold. All returned equipment is subject to a 15% restocking fee. We ship most orders within 2 days. WE ARE A MEMBER OF THE CHAMBER OF COMMERCE. RETAIL STORE PRICES MAY DIFFER FROM MAIL ORDER PRICES. PLEASE SEND ORDERS TO: COMPUTER STOP, 2545 W. 237 St., TORRANCE, CA 90505 Circle 80 on inquiry card. BYTE September 1981 465 Circle 238 on inquiry card. >!„,,,,_ SI 00 2032 32K STATIC RAM A&T 450 NSEC...S579 00. 300 NSEC S585.00. 200 NSEC...S629.00 2116 16K STATIC RAM A & T. 450 NSEC...S285.00. 300 NSEC .5289.00. 200 NSEC...S329.00 2065 64K DYNAMIC RAM A & T $548.95 2200 S-100 MAIN FRAM A&T S379.95 2<22 FLOPPY DISC WITH CP/M 2.2'" S329.95 2802 6502 PROCESSOR A&T S282.95 2610/1 Z80 CPU A& T $249.95 2710A4 SERIAL 1/0 A&T $291.95 2718* 2 SERIAL. 2 PARALLEL A&T $305.95 2720*4 PARALLEL A & T S214.95 PHOTO BOARDS WW . S39 95. SOLDERTAIL ..$29.95 APPLE PRODUCTS 7114A 12K ROM/PROM S68 50 7424A CALENDAR/CLOCK S106.95 7440A PROGRAMMABLE TIMER $98.50 7470A A TO CONVERTER S105.95 7490A GPIB (IE 488) INTERFACE S265.95 7710AASYNC SERIAL S1 25.95 7712ASYNC SERIAL S153.95 7720A PARALLEL STANDARD S98.95 7720B PARALLEL CENTRONICS $98.95 781 1 B ARITHMETIC PROCESSOR W/DISC S342.95 7811C ARITHMETIC PROCESSOR W/ROM S342.95 7500A WW BOARD $22.95 7510A SOLDERTAIt BOARD $23 95 SOFTWARE 2610 CP/NT MACRO ASSEMBLER ON DISK S76.95 2620 CP/M'" SYMBOLIC INSTRUCTION DEBUGGER . . . S64.25 2630 CP/M'"TEXT FORMATER S64.25 2640 CP/M'" BACKGROUND PRINT UTILITY $42.95 OTHER CCS PRODUCTS ARE AVAILABLE. CALL FOR PRICE. SStD MICROCOMPUTER PRODUCTS SI 00 PRODUCTS CBIA 8080 PROCESSOR PCBD.... KIT S155.95, A&T CB-2 280 PROCESSOR BOARD KIT $198.95, A& T . $32.95 $215.95 S269.95 VDIC 64 x 16 VIDEO. PCBD $32.95 KIT $153.95, A&T $199.95 VB2 64 x 16 VIDEO. PCBD $32.95 KIT $175.95, A&T $234.95 VB3 80 CHARACTER VIDEO 4MHZ KIT $345.95, A&T $425.95 UPGRADE RAMS FOR VB-3 S42.00 104 2 PARALLEL. 2 SERIAL, PCBD $32.95 KIT S155.95. A&T $194.95 PB-1 2708, 2716 PROGRAMMER BOARD. KIT S135.95. A&T $185.95 MB-10 16K STATIC RAM KIT S299.95. A&T S339.95 APPLE PRODUCTS A48B IEEE 488 INTERFACE $399.95 AID SERIAL/PARALLEL INTERFACE KIT S125.95, A&T S155.95 ASIO SERIAL I/O KIT S87.95. A&T $97.95 APIO PARALLEL 10 KIT(W/0 CABLES) $67 95, A&T(W/0 CABLES) S87.95 OTHER SSM PRODUCTS ARE AVAILABLE. CALL FOR PRICES. MONDAY-FRIDAY, 8:00 TO 12:00, 1:00 TO 5:30 THURSDAYS. 6:00 TO 9:00 P.M (415) 728-9121 P.O. BOX 955 • EL GRANADA, CA 9401 8 PLEASE SEND FOR IC, XISTOR AND COMPUTER PARTS LIST SEPT. SPECIAL SALE ON PREPAID ORDERS ICHARGE CARDS AND COD ORPO NOT AVAILABLE ON THESE OFFERS] WAMECO BOARDS WITH MIKOS PARTS 10% OFF ADVERTISED PRICE W777C inc. WAMECO INC. BOARDS WITH MIKOS PARTS MEM-3 32K STATIC RAM. PCBD $36.95 KIT LESS RAM $95 95, A&T $135.95 CPU-2 Z80 PROCESSOR, PCBD $32.95 KIT LESS ROM $109.95, A&T $149,95 EPM-2 16K/32K EPROM. PCBD $32.95 KIT LESS ROM $65.95, A&T $99.95 FPB-1 FRONT PANEL. PCBD $48.50 KIT $144.95, A&T $184 95 CPU-1 8080 PROCESSOR, PCBD $29,95 KIT $89.95, AS T $129.95 QMB-12 13 SLOT MOTHER BOARD. PCBD $39.95 KIT S95.95, A&T $135.95 OTHER WAMECO PRODUCTS ARE AVAILABLE. CALL FOR PRICES. MIKOS PARIS ASSORTMENTS ARE ALL FACTORY MARKED PARTS KITS INCLUDE ALL PARTS LISTED AS REQUIRED FOR THE COMPLETE KIT LESS PARTS LISTED ALL SOCKETS INCLUDED LARGE SELECTION OF LS TTL AVAILABLE. PURCHASE $50.00 WORTH OF LS TTL AND GET 1 0% CREDIT TOWARD ADDITIONAL PURCHASES. PREPAID ORDERS ONLY. VISA or MASTERCHARGE Send account number, interbank number, expiration dale and sign your order Approx postage will be added Check or money order will be sent posl paid in u S II yon are not a regular customer, please use charge, cashier's check or postal money order Otherwise there will be a two-week delay lor checks to clear Calif residents add 6" b tax Money back 30-day guarantee We cannot accept returned IC's that have been soldered to Prices subject tc change without notice S 1 mliiiruim order. SI. 50 service charge on order! leu thin s 1 0.00. STOP LOOK LISTEN DON'T TURN THIS PAGE. . . AT THESE POPULAR. . . .if you are tired of dealing with mail order houses that never have in stock what you need, when you need it. We are not a mail order house. Micro Source of Texas is a stocking wholesale distributor of microcomputer printers, video display terminals, and supplies. What makes us different? We don't just take orders! Whether you're a dealer, systems integrator or first-time micro user, you expect help from your supplier in determining the best product to fit a particular application. We give that help, and more. Since complete doc- umentation is essential, we provide it with every order we ship. And if you're located in Texas, stop by and we'll demonstrate our products without obligation. Try to do that mail order! Don't waste valuable time. Talk to Micro Source. We can help. . . .low cost, high quality products: • EPSON MX-80 matrix printer • C.ITOH "Starwriter" WP printer • TELEVIDEO Model 910 CRT terminal and many more! What about supplies? No hassle. We stock ribbons and accessories for EPSON, C.ITOH, DIABLO, QUME, NEC, DEC, and CENTRONICS printers. All products and supplies are in stock, available for immediate delivery. Micro Source of Texas is a specialty distributor handling only peripheral hardware. We don't sell microcom- puters or software. So if you're a systems dealer, consider us a depend- able supplier, not a competitor. Micro Source wants to be your source. Micro Source of Texas, Inc. 834 N Glenville Drive Richardson. Texas 75081 214-690-5111 TO WHAT WE OFFER. . . LOW PRICES The best in the industry! Because of our volume purchases, we offer at- tractive discounts to independent deal- ers and micro systems builders. Call or circle our reader inquiry number and receive a current dealer price list and catalog. IMMEDIATE DELIVERY We stock a variety of popular micro printers and display terminals includ- ing EPSON, C.ITOH. and TELEVIDEO. If your needs are immediate, we'll ship within 24 hours of receiving your order. And if you're nearby, just drop in and pick up your order the same day. TECHNICAL ASSISTANCE Micro Source offers in-depth appli- cation assistance to Apple, Commodore, and TRS-80 dealers, among others. We want you to buy the right product with the right interface at the right price. Product support and courteous service are "standard features'' with Micro Source. Call today and make us prove it! WE'RE IN TEXAS Ask about our NO FREIGHT CHARGE special offer to Texas customers 466 BYTE September 1981 Circle 226 on inquiry card. DOWN-TO-EARTH PRICES ON OUT-OF-THIS-WORLD PERSONAL COMPUTERS AND COMPONENTS. Look at these easy hardware prices: Look at this! Ohio Scientific Superboard II $329 • 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 8K • Full 53-key keyboard, with upper and lower case. Plus user expandability. • Video interface and audio cassette interface. The Ohio Scientific Superboard II at $329 — 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." —BYTE, MAY 1 979 610 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 PS-003 1 2V power supply for mini-floppies. 45 RF Modulator Battery powered UHF Unit. 35 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. ■ Hours: Call Monday thru Friday. B:OD AM to 5:00 PM E.D.T. TOLL FREE: 1-800-321-5805 Guaranteed Shipment Cleveland Consumer Computers & 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. i l I I I I : I 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 call: [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 I ■■ Ml ■■■■■■■■^H ■■■■§■■ Mi HUM ■■■■■■ l flnrlan Cnn rwi ■ CLEVELAND CONSUMER P.O. Box 46827 UlUCr rUI III. COMPUTERS & COMPONENTS Cleveland, Ohio 44146 D Superboard II £329. □ RF Modulator £35. □ 61 Board $298. □ AC-3P 1 2 " BAA/ Monitor £1 59. □ Mini-Floppy Disk Drive $299. □ C1 P Sams Manual $8. [Attach separate sheet for other items.] NAME ADDRESS: CITY: PHONE: STATE: ZIP: Payment by: VISA MASTER CHARGE MONEY ORDER Credit Card Account # Expires . . Interbank #[Master Charge] TOTAL CHARGED OR ENCLOSED £_ . [Ohio Residents add 6.5% Sales Tax] Orders of less than SI 00, please add $4.00 to cover shipping costs. Orders will be accepted from U.S. and Canada only. All prices quoted are U.S., date of publication, standard UPS shipping FOB the factory. PRICES SUBJECT TO CHANGE WITHOUT NOTICE Circle 62 on inquiry card. BYTE September 1981 467 COMPUTERS ATARI" 800™ COMPUTER SYSTEM 16k-*750.00 48k-*898.00 APPLE II Plus" 4S*-*119 64/c-*13S kgs 74S00 74SOO 74S02 74S03 74S04 74S05 74S10 74S15 74S20 74S22 74 530 74S37 74S50 74S51 74S64 74S74 74S86 74S112 74S132 74S138 74S140 74S158 74S174 7451 75 74S182 74S189 74S201 74S240 745244 74S251 74S287 745288 74S299 74S470 74S471 74S473 74S474 COMPONENTS CONT'D {video too MONITORS video mo 112 1. |12mhi I BLACKS WHITE IVIDEO MONITOR |AMMK i LEEDEXj Corp. 12MHz AMDEK' GREEN Phos VIOEO MONITOR *365°° 1971 SO. STATE COLLEGE ANAHEIM, CALIF. 92806 *10.MIN ORDER/ CA. RES. ADD 6°/< FRT . . . 5N740ON 5N7402N SN7404N SN7408N SN7410N SN741 2N SN7413N SN7414N SN7416N SN7417N SN7420N SN7425N SN7430N SN7437N 5N7438N SN7440N 5N7442N SN7443N SN744SN SN7451N SN7454N SN7474N SN7475N SM7482N SN74»2N SN7493N SN7405N SN7490N SN74122N SN74136N SN74141N SN74151N SN74153N SN741S4N SN74155N SN74157N SN74160N SN74161N SN74163N SN74164N SN74165N SN74174N SN74175N SN741BON SN7410IN SN74393N 74LS00 74LSOO 74LS02 74LS03 74LS04 74LS05 74LS06 74LSOS 74LS10 74LS14 74LS20 MLS21 74LS20 74LS27 74L528 74LS30 74LS32 74LS38 74 L 542 74LS48 74LS74 74LS75 74LSB6 74LS00 74L593 MLsee 74LS107 74LS113 74 LSI 22 74 LSI 23 74LS125 74LS126 . 74 LSI 38 74 LSI 39 74LS151 74 LSI 53 74LS157 74 LSI 50 74LSW1 74L5162 74LS163 74LST64 74 LS165 74 LSWS 74 LSI 70 74 LSI 74 74LS175 74LS10O 74LS191 74LS196 74 LS1Q7 74 LS221 74LS240 74 LS241 74 LS243 74 LS244 74 LS245 74 LS251 74LS253 74LS257 MLS259 74L5260 74 LS273 74LS279 74LS200 74 LS203 74LS365 74 LS3*7 74LS373 74LS3W 74LS377 74LSM0 74LS670 EPROMS 2716 6.95 ea 5V 450MS TMS2716 2708 8 25ea 450NS 4.10 m 8 lot 6.2503 8 tor 7 50ea 8 (Of 3.95ea 2732 I9.96ea 4 tor 16.95*a 4116 300MS 2 00ea 8 (or 14 00 200NS 235«a 8 (or 16.00 2114L 3O0NS 29Sea4tor 2.75*a 200NS 3.50ea 4fOf 3.00ea 2111 450NS 250ea»for 2 OOea CPUs 2 80 Z 6GA CTC Z BOA CPU Z 80 002 16-64K 2901 A MC6800 MISC. 2102 450NS 8038 NE555 AYS 101 3 A 1488 1489 8T26 BT28 8212 8216 IS410SCR IT410TT11AC 7905 7906 7915 791 B 7805 7806 7BOB 7812 MC1330A1P MC1350P MC1358P LM380 LMS65N LM741 MC1458P LM720 LM386 1981 I.C. MASTER * 59.95 7.95 10.50 10 50 129.00 13.50 7.50 9.50 1103A UPD765 (loppy disk control lot ULN20O1 TMS4400 MC4008P MH0026 D3624 D3O01 D3002 85 IC SOCKETS .85 8 PIN 10/1.20 14 10/ 1.40 16 10/1.60 18 10/1.90 20 10/2.80 22 10/2.80 24 10/2.80 28 10/3.80 55 40 10/4 75 TERMINALS *68ft00 Synertek "KTM-3" LOW COST TERMINAL WITH KEYBOARD AND VIOEO 100 „ * <499.00 * ** SPECIALS** 3it*« MUFFIN FAN »/i,n. <»«! •9 96 UPD 765C Floppy Olak Controls •17.96 »;w«'. 2732A: »0nsec. EPRO* •24.50 AY5-1013A:3WbM UAST •!» REAL-TIME CLOCK CALENDAR (MSM5832) DtttflftM. Mono Matal Cut. CMOS I C faUltl Tana, Month. Data,\»jar. 1 'Oavotwaak ■BlMOrlontod ■t Bit Data Sua -4 Bit Addr.is ■"/WHoMSflK. ■Intar. Signal XTAL ■32 768Ktw xtal Control *3-85 ' 5v Row Sup 'Low Powat Dlaatpation *7.45 l/SKd GLOBAL Logic Probes LP_1: *40.oo Pui«« width io ratMtOlOrn'ru LP-3: *6a00 Pulse width to 6TMC R*D to ov.l 6OMH1 OR SHELF/ DESK MOUNTED*5722 $155°° DESC- II W CHMtllli IIEI11I HUt III HiKKWill tint* Mill Kiwiii muam/ nmm :< fin in wicid m i iiHi POWER, (SUPPLY MODEL *CP198 input — I107l25v output — 5vdc u 6amps '.29.95 Apple Expansion Kit 16K Memory Add-On Includes Instructions $25 95 TRS8O 16K Add -On Instructions* Dip Switches $25.95 LPK-1: LoflK Probe Kit-comptote nothing oitra to buy Mm. pulse width UOnaK- *ia95_ CARDS MICROSOFT Z80. $ 295°° 16K RAM $16000 VIDCX VIDEOTERM BO column *295°o KEYBOARD ENHANCER *120°° CALIF COMPSVS APPLE CLOCK *12400 PROTO BOARD *25°° PRINTERS EPSON MX- 80 *5600o CENTRONICS 737-1 *950°° 753-1 *2.995P° BASE II. inc 8006 *649°° I 850 *749°° FLOPPY DISK DRIVES Qume Datatrak-8 $540 Virtually the industry standard. High quality/reliabil- ity. Full featured, double-sided, double density. SA851 $540 Full featured drive, double sided, double density SA801R $395 Single sided, double density, very consistent FDD100-8 $395 Qume Datatrak 5 5%" $345 SA-400 5%" $299 Tandon TM-100-2 S%" $350 We are expecting a large shipment of mini's, many types. Call for details. CONTROLLERS Tarbell single density kit $195 -'A 8 * Tarbell single density A&T $310 S^S^SS' Tarbell double density A & T $425 3* *J||«s CCS 2422 w/CPM 2.2 $350 ||§i| ^m~ Godbout Disk 1 $450 MDA MXV-21 LSI-1 1 controller $1050 (RX-01, RX-02 compatible) MISCELLANEOUS CCS Mainframe $395 2 Disk drive enclosure $ 95 (fits Siemens, Shugart, Qume) CP-206 power supply $110 (powers two floppies) Cable Kits 2 drives $ 35 3 drives $ 40 4 drives $ 45 Diskettes ss $39/10 - ds $59/10 CPU CCS 2810 $ 275 Godbout Z-80A $ 275 Godbout 8085A $ 295 MEMORY CCS 2065 64K dynamic $ 625 CCS 2116 32K static $ 675 Godbout RAM 17 64K $1250 I/O CCS 2710 4 SIO $ 325 Godbout Interfacer 1 $ 225 Godbout Interfacer 2 $ 225 Qume S/5 — Daisy Wheel Printer Sprint 5/45 RO $2699 Sprint 5/55 RO 2829 Sprint 5/45 KSR 3029 Sprint 5/55 KSR 3159 Forms Tractor 210 Pinfeed platen 1 55 Paper Guide 30 Paper Basket 50 many print wheels, ribbons, & more available. Terms of sale: cash or checks, purchase orders from qualified firms and institutions. Minimum order $25. CA residents add 6% tax. Prices subject to change without notice. All goods subject to prior sale. Minumum shipping/handling charge $4.00. Electrolabs POB 4436, Stanford, CA 94305 (415) 321-5601 Circle 132 on inquiry card. INCREDIBLE? believe Qantex 6000 PRINTERS 150 cps bidirectional-9x9 dot matrix, quietized case, 136 col, vertical form control and many other functions SHQR We feel this printer offers * I 1 33 the best price/performance ratio available. RS-232 serial to 1 9,200 baud x-on, x-off add $40 rjT^ Teletype 40, 300 LPM-typewriter quality, RS- from Only 232 interlace. This quality printer is available in many $2928 configurations including forms access, quietized case, etc. Teletype 43 from $995 Teletype AP-200, 340 cps dot matrix (similar to Data Prod. M-200) S2799 NEC Spinwriter-55 cps, bidirectional, letter quality R.O. S2660 KSR $2942 DIABLO 630-40 cps, bidirectional, daisy wheel, plot/graph $2449 C. ITOH Starwriter, 25 cps, daisy wheel $1 575 C. ITOH Starwriter. 45 cps, daisy wheel $1849 EPSON MX-80, 80 cps, 9x9 dot matrix SCALL ANADEX 9500/9501 , up to 200 cps, high resolution dot $1349 OKIDATA Microline 80, 80 cps, 9x7 dot matrix $490 Microline 82, bidirectional, friction/pin feed $599 Microline 83, bidirectional, 120 cps, uses 15" paper $875 TI-810, 150 cps, Basic $1695 Package-Compressed print, vertical form control $1830 CENTRONICS 704-9,1 80 cps, 9x9 dot matrix, 132 col, RS-232 $1595 704-11,180 cps, 9x9 dot matrix, 132 col, parallel $1695 730,100 cps, 7x7 dot matrix, same as RS. LPII $660 737.80 cps, nx9 dot matrix, same as R.S. LPIV $849 739 Graphics SCALL DECLA-34 $1085 IDS460G $1199 S-100 SPEC IALTIES DP1Z-80A, CPU, 64K ram, floppy cont., RS-232 port, SI00 IEEE, 8 slot in adds terminal, inc. CP1M2.2 SCALL Delta has Winchester based networks of up to 1 6 users available. ES2S3 Crou p Ca " us ,or best pnces on these hign Q ua||, y generation boards and systems. |P California These high quality, reliable products have made CCS |^" Computer defacto industry standard for S-100 products ■I Systems Assembled and tested: list only 2200 H.D. Mainframe, 20 a. P. S., 12 slot MB $434 $359 2065C 64K dynamic RAM/Bank Select $720 $580 2810A Z-80 CPU, serial port, ROM monitor $310 $259 2422A Floppy Cont, CP/M 2.2, ROM monitor $425 $345 , 8000 DT — w/1 64k. 1 .2 MB 8" floppies, 2 serial, 3 par. CPM 2.2 $CALL FULL 2 YEAR WARRANTY! Z-80 CPU $310 D2 Disk controller $354 64K Dynamic Ram $648 /HICROBYTE FULL SYSTEMS AVAILABLE SUPERBRAIN Scall Similar savings on the full lines of CCS, SSM, NNC, MORROW, DELTA, NORTHSTAR, ITHACA INTERSYSTEMS, GODBOUT, NEC. TELEVIDEO, IMS ZENITH, ADDS, DEC, DATA GEN., ATARI, DYNABYTE. ®.® $450 $625 2 fo r$1199 $299 $445 $963 $1259 List only $5350 Scall $6450 Scall $750 Scall $790 Scall $4995 $3995 $1500 $1275 $6995 $5995 $5995 $5099 8" DISK DRIVE SALE 8"SHUGARTSA801R QUME DATATRACK 8 Enclosure, power supply for 2 8" drives A&T NNC industrial grade enclosure for 2 drives with PS. MORROW Discus 2D + CP/M® Discus 2 + 2 + CP/M® HARD DISK SPECIALS C0RVUS 10MB and controller 20MB and controller Constellation Network Multiplexer Mirror Video Tape Disk Backup MORROW 26MB + controller + CP/M 2.2® CAMEO cartridge drive controller , controller, CDC Hawk Drive (5 fix, 5 rem) controller, Western Dynex (5 fix, 5 rem) d^ Winchester 5Vi drives complete with case, cable £llv software, S-100 controller. Adapter avail, for use with ^p XCOMP any Z -80 system . Cartridge drive controllers avail Ljst 5MB $2898 10MB $3398 Quantity discounts available! | r.v-r-i | S " 100 CONTROLLER FOR PRIAM $693 I 1 * ' 1 PRIAM 8" and 1 4" Winchester/tape subsystems avail. We carry the full line of ADES disk and tape controllers and subsystems. FULLY CONFIGURED BUSINESS SYSTEMS The following are some examples of the fully assembled and tested business and scientific computer systems which we offer. All include CP/M 2.2, 64K bytes dynamic RAM, Z-80A 4mh CPU. We offer a full line of quality, tested software. Delta TVD w/1 .2 Mb floppy drives, 2 serial, 3 parallel ports $CALL Delta 1 004 w/1 MB hand disk, 1MB floppy, 6 serial, 3 parallel ports SCALL CCS 2210A w/floppy controller, 1 serial port $1849 CCS 300-1 A w/1 .2MB floppy drives, 2 serial, 2 parallel ports $4849 CCS 400-1 A w/1 0MB hard disc, 2 serial, 2 parallel ports $6999 Optional CP/M for CCS 300, 400 (OASIS available) $150 NNC 80 w/1 MB floppy drives, 2 serial, 3 parallel ports $3799 NNC 80W W/.5MB floppy, 8.4MB hard disc, (OASIS optional) $6693 ALTOS single and multi-user systems Scall MORROW Decision 1 , MICROSOFT basic, UNIX Scall TERMINALS AMPEX DIALOGUE 30, 80 TELEVIDEO 912 C $950 920 C $1030 950C SOROC 10120 IQ 140 INTERTUBE III or EMULATOR (multi-terminal) DECVT-100 Similar savings for our HAZELTINE and LEAR SIEGLER lines LOOK HERE! aivipex Call us for ALL your softwear needs Dialogue 80 SYSTEMS HOUSES & EDUCATIONAL INSTITUTIONS GIVEN SPECIAL CONSIDERATION. $1195 $995 $1395 S895 $2050 SCALL $725 $789 S989 $729 $1149 $799 $1575 ALL OF OUR PERIPHERALS CAN BE CONFIGURED FOR RADIO SHACK" MODEL I DEALER and INTERNATIONAL INQUIRIES WELCOME WASHINGTON COMPUTER SERVICES anaffiliateof (((WASHINGTON))) est. 1912 w E6ECTRtC COflftPdNY '" CUSTOM COMPUTER ROOM WIRING SINCE 1960 97 Spring Street New York, N.Y. 1001 2 Hours: 8AM-5:30PM (EST) Mori. -Fri. Circle 381 on inquiry card. TO ORDER: CALL OUR TOLL-FREE NUMBER: • (800) 221-5416* In N.Y. State and for technical information call 1(212) 226-2121 For fast delivery, send certified checks, money order or call to arrange direct bank wire transfers. Personal or company checks require two to three weeks to clear. All prices are mail order only. Prices subject to change without notice; call for latest prices. Prices include 2% cash discount. N.Y. residents add sales tax. Quantex is a trademark of North Atlantic Industries, Inc. Radio Shack* is a trademark of the Tandy Corp. CP/M® is a trademark of Digital Research BYTE September 1981 469 Circle 283 on inquiry card. SAVEUP TO $600.00 NOW on TRS-80 Computers & Accessories With This Coupon Now you can own a great little computer at a great big dicount off the manufacturer's list price. For home or office use the Radio Shack line of computers is first in quality, performance and price. • FREE SHIPPING in the 48 continental contigious states. Model • NO SALES TAX collected on out-of-state orders. • CONVENIENT ORDERING Call us TOLL FREE. • FREE COMPLETE PRICE LIST available upon request. Catalog Charge Number Description List Price By Phone Radio Shack® TRS-80 Model II 26-4002 64K 1-Disk Model II 3,899.00 3,579.30 Radio Shack® TRS-80 Model III 26-1062 Model III 16K 999.00 865.00 26-1066 Model III 48K 2,495.00 2,243.50 Radio Shack® TRS-80 Color Computer 26-3001 4K Color Computer 399.00 359.10 26-3002 16K Color Computer 599.00 539.10 Atari® CX-2600 Video Computer System 180.00 164.95 Pioneer® VP-1000 LaserDisc Player CALL FOR PRICES Mattel Electronics® Intellivision" Home Video System CALL FOR PRICES Magnavox® Odyssey 2 Home Video System CALL FOR PRICES Magnavox® Magnavision® Videodisc Player CALL FOR PRICES J Cashier's Check Or Money Order *3,299.00 865.00 *2,149.00 359.10 539.10 164.95 Cash Price You Save 600.00 134.00 346.00 39.90 59.00 15.05 Pan American Electronics CALL TOLL FREE 800-531-7466' Dept. 19 (Operator 19) • Texas & Principal Number 512/581-2766 1117 Conway Avenue • Mission, Texas 78572 NEW BRANCH 2912 N. Main. Fort Worth. Texas 76106 » Phone Number 817-625-6333 » Telex 794836 Telex 767339 TRS-80 is a Trademark of Tandy Corp. 'With this coupon only! Prices subject to change without notice. SUNNY LOW LOW COST POWER.SUPPLIES FOR S-100, FLOPPY DISKS. KIT 1, 2 & 3 For S-100 R3 For Three 8" or 5W Disk Drives S-100 POWER SUPPLY KITS (open frame with base plate, 3 hrs. assy, time) ITFM USED FOR @ - 9 Vdc @ + 16 Vdc @ + 28 Vdc SIZE W x D x H S3 2 in 1 Unit for S-100 and two 8" or 5Vi" Disk Drives. It fits most Disk System Mainframes. PRICE KIT 1 15 CARDS SOURCE 15A KIT 2 SYSTEM SOURCE 25A KIT 3 DISK SYSTEM 15A 1A 2.5A 3A 2A 25A 3A 2A 4A 12" 12" 14" 4V 4'/a" 4'/s" 52.95 59.95 67.95 DISK DRIVE POWER SUPPLY "R3" regulated, open frame, assy. & tested 67.95 SPECS + 5V @ 5A OVP. -5V @ 1 A + 24V@ 5A. SHORTS PROTECT 2 SIZES AVAIL ,1)9" (W) x 6V„" (D) x AH" (H). 2) 9" (W) x Ah" (D) x 5Vt" (H) OPTION 1 ) REPLACE + 24V BY + 12V. 2 ) FOR SIZE 1 ONLY. ADD + 12V @ 1A. AT AN ADDITIONAL $12 00 IDEAL FOR THREE 8" or 5'A FLOPPY DISK DRIVES. SUCH AS SHUGART 801/851. SIEMANS FDD 100-8/200-8 OR 100-5 ETC DISK SYSTEM PWR SUPPLY "S3" open frame, assy. & tested, compact size: io"(w) * 6- p) >. 5" I S-100 bus compatible • Reads and writes single or double density • Density is software selectable • Controls up to four 5-1/4" or 8", single or double- sided drives "Single or double-sided drives may be mixed in the same system • On-board Z-80A to assure reliable operation • EIA level serial printer interface on board, baud rates to 9600 (perfect for despooling operations) • Uses IBM standard formats • Designed to meet IEEE signal disciplines • Works with 8080, 8085, and Z-80 CPU's. IOD-1200B Bare Board $59.95 IOD-1200K Kit $299.95 IOD-1200A A&T $375.00 SFC-58001200E DD boot PROM .... $20.00 S FC-59002001F CP/M2.2forDD . $149.9 5 JADE Memory Bank ™ 8 or 16 Bit Dynamic Memory A 64K S-100 dynamic memory that looks toward the future. • S-100 standard pinout and signal discipline • 8 or 16 bit words, automatically, depending on the type of CPU on the bus • 4-layer PC board designed for extremely low-noise operation. With its on-board refresh controller, this board allows DMA operations without regard to time factors. It will'run reliably at any system clock rate up to 4 MHz-because it is clocked with the system clock itself (no one-shots are used for timing operations). Its unique design enables it to switch from a 64K by 8-bit board to a 32K by 16-bit board automatically (responds to IEEE's 16 Rqst line and, if enabled, replies with 16 Grant). MEM-99730B Bare Board $49.95 MEM-99730K Kit, no RAM $i99.95 MEM-16730K 16K kit $219.95 MEM-32731K 32K kit $239.95 MEM-48732K 48K kit $259.95 MEM-64733K 64K kit $279.95 Assembled & Tested add $50.00 4 MHz Z-80 CPU, 80 x 25 display with graphics and 8 colors, 32K RAM, 24K ROM, parallel /serial/ cassette interfaces, upper/lower case, numeric keypad, 10 special function keys, uses CP/M 2.2. NEC-8001A 32K CPU/keyboard .. $1095.00 NEC-8012A I/O with 32K RAM . . . $695.00 NEC-8031A Dual disk unit $1095.00 VDM-651200 12" green CRT $269.95 NEC-1202D Hi-res RGB color CRT $1045.00 NEC-90005 Gen. accting softwr . . . $375.00 JADE The Big Z Z-80A Based CPU TM S-100 bus compatible • Switch selectable 2 or 4 MHz operation • Serial I/O port • Accomodates a 2708, 2716, or 2732 EPROM in shadow mode allowing full use of 64 K RAM • MWRITE signal is generated automatically if used without front panel • On-board 8251 USART controls serial port at baud rates from 75 to 9600 baud • Switch selectable IK, 2K, or 4K boundary fully buffered • Power-on jump to EPROM CPU-30201K Kit $139.95 CPU-30201A A&T $189.95 CPU-30200B Bare board $35.00 Memory Chips on Sale 21111 . 1 MHz 3.35 2.99 2.75 2.49 2708 2 MHz 4.90 3.90 3.45 2.90 2532 2 MHz 24.90 19.90 15.90 12.90 2716 2 MHz 8.90 7.45 6.45 5.75 2716 ■1 MHz 19.90 15.45 13.45 11.75 2732 2 MHz 24.90 19.90 15.90 12.90 2732 ■1 MHz 39.90 29.90 24.90 19.90 2758 2 MHz 6.90 6.25 5.50 4.50 4116 201) MS 3.25 2.99 2.49 1.99 1164 200 ns 28.90 24.90 22.90 19.90 JADE Disk Sub-Systems Shugart, Siemens, Qume Handsome metal cabinet with proportionally balanced air flow system • Rugged dual drive power supply • Power cable kit • Power switch, line cord, fuse holder, cooling fan • Never-Mar rubber feet • All necessary hardware to mount 2- 8" disk drives, power supply, and fan • Does not include signal cable Dual 8" Subassembly Cabinet END-000420 Bare cabinet $59.95 END-000421 Cabinet kit $225.00 END-000431 A&T $359.95 8" Disk Drive Subsystems Single Sided, Double Density END-000423 Kit w/2 FDlOOSDs .. $975.00 END-000424 A & T w 2 FDlOO-HDs $1175.00 END-000433 Kit w/2 SA-SOIRs . . . $999.95 END-000434 A & T w/2 SA-801Rs $1195.00 8" Disk Drive Subsystems Double Sided, Double Density END-000426 Kit w 2 DT-Hs $1475.00 END-000427 A & T w/2 DT-tis ... $1675.00 END-000436 Kit w/2 SA-851Rs .. $1495.00 END-000437 A&T w/2 SA-851Rs $1695.00 Circle 178 on Inquiry card. JADE S.P.I.C. Our "SPICy" New I/O Board .„..'. ;_,. '■■'■ -. Ti-wWt ''■■■ ■ ;'t?~'7,7 w i; ■ I 1 -' ■K-^;-#-JB^^r=rrL-^-~-..~.rv.v---^; Sk! 1 7)i ",. ~ jj ■""■ jmnrnmnnmi IHIMIHJUH New, from JADE, one of the most advanced, technologically sophisticated Serial/Parallel Interrupt Controller systems in the world. On a single IEEE S-100 standard board, JADE has packed two bi-directional parallel ports with full handshaking, four serial channels (asynchronous, IBM-compatible bi-synch, synchronous, HDLC/SDLC) with full and complete modem control lines, and 16 counter-timer channels. Utilizing the highly advanced Zilog peripheral chips, (Z-80 SIO, PIO & CTCs), the SPIC board is fully programmable to serve as the foundation for a multi-user multi-tasking system. Each of the seven Z-80 peripheral chips can generate its own interrupt vector, with daisy-chain priority levels. Each counter-timer channel can be programmed to monitor an interrupt vector line on the S-100 bus. Each SIO channel can be driven independently with separate Tx/Rx clocks so your peripherals can have varied baud rates from 110 to 76,800 baud. IOI-1045B Bare Board $49.95 IOI-1045K 2 CTCs, 1 SIO, 1 PIO ... $179.95 IOI-1045A A&T $239.95 IOI-1046K 4 CTCs, 2 SIO's, 1 PIO .. $219.95 IOI-1046A A&T $299.95 Build It Yourself and Save $1850 Complete S-100 Micro-Computer Kit 4 Mhz Big Z CPU, 64K Memory Bank, Double-D disk controller, 12 slot mainframe, dual disk sub- assembly with 2 double density 8" disk drives & power supply, ADDS Viewpoint terminal, CP/M 2.2, boot PROM, system monitor, & all necessary cables and manuals - PLUS FREE Business Software Package. Save over $1850.00 $2795.00 Jade Business Software Now, for the first time, at an amazingly low price, CP/M and SDOS users can get an affordable business software package. Just look at these programs! All come complete with basic code (written to run under CBASIC T), for easy customizing and modification. All software is self-documenting. The package price includes a word-processing system. When printed on the system's printer, all files with the extension xxxTOT. constitute a complete manual. No manuals are supplied with the package other than as they appear on the disks. All software is supplied on 8" premium quality JADE Diskettes. Software sold as is. (Sorry, but at these low prices we can not offer our usual friendly support and handholding.) Includes; General Ledger, Payroll, Invoicing, Inventory Control , Accounts Recievable, Cash Disbursements, Fixed Assets, Cash Receipts, & Mailing List Management. Special Package Price $249.95 Printers Accessories for Apple Single Board Computers BEST BUY in PRINTERS - Epson MX-70 132 column, 80 CPS, 5x7 dot matrix, adjustable tractor feed, & graphics PRM-27070 List $459 $399.95 MX-80 132 column, 80 CPS, bi-directional/logic seeking printing. 9 x 9 dot matrix, adjustable tractor feed, & 64 graphics characters PRM-27080 List $645 $474.95 MX-80FT same as MX-80 with friction feed and full graphics added PRM-27082 List $745 $574.95 MX-100 233 column, correspondence q uality . ultra-high resolution graphics, up to 15" paper, friction feed & removable/ adjustable tractor feed, 18 xl8 dot matrix, 80 CPS, programmable forms handling PRM-27100 List $945 $795.00 PRA-27084 Serial interface $69.95 PRA-27088 Serial intf&2K buffer .. $144.95 PRA-27081 Apple card $74.95 PRA-27082 Apple cable $22.95 PRA-27086 IEEE 488 card $52.95 PRA-27087 TRS-80 cable $32.95 PRA-27085 Graftrax II $95.00 PRA-27083 Extra ribbon $14.95 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 Accessories for TRS-80 DISK DRIVES for TRS-80 2396 more storage, 8 times faster, 40 track with free patch, 120 day warranty. MSM-12410C Save $125.00 !!! $325.00 8" DISK DRIVES for MODEL II 2 double density drives with cabinet, power supply, & cables END-000433 Kit $1050.00 END-000434 Assembled $1250.00 WCA-5036A Cable (required) $29.95 16K Atari . . . $359.95 ATARI 800 - Atari Complete personal computer with high resolution color graphics, built-in RF modulator, 4 controller ports, internal speaker, I6K RAM & 8K ROM SYO-2080A 16K Atari 800 $759.95 Atari 800 with 32K of RAM $799.95 Atari 800 with 48K of RAM $849.95 SYO-2040A WK Atari 400 $359.95 MSM-330810 Disk drive $595.00 MSM-330815 Dual drive $1395.00 IOX-5050A 850 interface $199.95 MEX-16853K WK RAM module $69.95 SFI-241011005 Visicalc $184.95 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 fas specified by the manufacturer), all necessary jumper blocks, fool-proof instructions, and our 1 year guarantee. MEX-16100K TRS-80 kit $25.00 MEX-16101K Apple kit $25.00 MEX-16102K Exidy kit $25.00 16K RAM Card - Microsoft (There is life after 48K) MEX-16300A A & T $174.95 Z-80* CARD for APPLE Two computers in one, Z-80 & 6502, more than doubles the power & potential of your Apple, includes Z-80* CPU card, CP/M 2.2, & BASIC-80 CPX-30800A A&T $299.95 APPLE CLOCK - Cal Comp Sys Real time clock w/battery back-up IOK-2030A A&T $109.95 DISK DRIVE for APPLE o'/i" disk drive with controller for your Apple MSM-12310C with controller $475.00 MSM-123101 w/ out controller $375.00 8" DRIVES for APPLE Controller, DOS, two 8" double densisty drives, cabinet, power supply, & cables Special Package Price Kit $1399.95 PRINTER INTERFACE - CCS. Centronics type I/O card w/ firmware IOI-2041 A A&T $99.95 AIO, ASIO, APIO - S.S.M. Parallel & serial interface for your Apple (see Byte pg 11) IOI-2050K Par&Serkit $139.95 IOI-2050A Par & Ser A & T $169.95 IOI-2052K Serial kit $89.95 IOI-2052A Serial A&T $99.95 IOI-2054K Parallel kit $69.95 IOI-2054A Parallel A&T $89.95 A488 - S.S.M. IEEE 488 controller, uses simple basic commands, includes firmware and cable, I year guarantee, (see April Bytepg 11) IOX-7488A A&T $399.95 CPS MULTICARD - Mtn. Computer Three cards in one! Real time clock calendar, serial interface, & parallel interface - all on one card, IOX-2300A A & T $199.95 Apple-CAT - Novation Software selectable 1200 or 300 baud, direct connect, auto- answer/auto-dial, auxiliary 3-wire RS232C serial port for printer. IOM-5232A Save $50.00!!! $339.95 AIM-65 - Rockwell 6502 computer with alphanumeric display, printer. & keyboard, and complete instructional manuals CPK-50165 IK AIM $424.95 CPK-50465 4K AIM $499.95 SFK-74600008E 8K BASIC ROM . . . $99.95 SFK-64600004E 4K assembler ROM $84.95 PSX-030A Power supply $64.95 ENX-000002 Enclosure $54.95 -IK AIM. 8K BASIC, power supply. & enclosure Special package price $675.00 Z-80* STARTER KIT - SD Systems Complete Z-80* computer with RAM. ROM. l'O, display, keyboard, manual, and kluge area, CPS-30010K Kit $369.95 CPS-30010A A&T $459.95 SYM-1 - Synertek Systems /-pad. Single board computer with 1 K of RAM. I K of ROM. ke LED display. 20ma & cassette interface on board. CPK-50020A A&T $249.95 Video Terminals VIEWPIONT - ADDS Detachable keyboard, serial RS232C interface, baud rates from 1 10 to 19,200, auxiliary serial output port. 24 X 80 display. tillable screen, international character set VDT-501210 Sale Priced $639.95 TELEVIDEO 950 Detachable keyboard, split screen with line lock, etched CRT. programmable function keys, on-screen status line, buffered auxiliary port, 14 x 10 dot matrix, self test, serviced nation- wide by General Electric VDT-901250 List $1195.00 $995.00 Video Monitors Leedex / Amdek Reasonably priced video monitors VDM-801210 Video 100 12" B&W . . $139.95 VDM-801230 Video 100-80 12" B& W $179.95 VDM-801250 12" Green Phospor .... $169.95 VDC-801310 13" Color I $379.95 13" COLOR MONITOR - Zenith The hi res color you've been promising yourself VDC-201301 $449.00 12" GREEN SCREEN - NEC 20 MHz, P31 phosphor video monitor with audio, exceptionally high resolution - A fantastic monitor at a very reasonable price VDM-651200 12" monitor $269.95 EPROM Erasers EPROM ERASERS L.S. Engineering UV eraser for up to 48 EPROMs XME-3200 A&T $39.99 Faster Service. S-100 PROM Boards S-100 Memory S-100 CPU PB-l - S.S.M. 2708. 2716 EPROM board with built-in programmer MEM-99510K Kit $154.95 MEM-99510A A&T $219.95 PROM- 100 - SD Systems 2708. 2716. 2732. 2758. & 2516 EPROM programmer MEM-99520K Kit $219.95 MEM-99520A Jade A&T $269.95 EPROM BOARD - Jade 16K or 32K uses 2708's or 2716's, IK boundary MEM-16230K Kit $79.95 MEM-16230A A&T $119.95 S-100 Video VB-3 - S.S.M. 80 characters x 24 lines expandable to 80x48 for a full page of text, upper & lowercase, 256 user defined symbols, I60x 192 graphics matrix, memory mapped, has key board input. 1OV-1095K 4 MHz kit $349.95 IOV-1095A 4 MHz A&T $439.95 IOV-1096K 80 x 48 upgrade $39.95 VDB-8024 - SD Systems 80 x 24 I/O mapped uideo board with keyboard I/O. and on-bnard Z-80 A*. IOV-1020K Kit $399.95 IOV-1020A Jade A&T $459.95 VIDEO BOARD - S.S.M. 6-4 characters x 16 lines, 128 x 48 matrix for graphics, full upper/lower case ASCII character set, numbers, symbols, and greek letters, normal/reverse/blinking video, S-100. IOV-1051K Kit $149.95 IOV-1051A A&T $219.95 IOV-1051B Bare board $34.95 Motherboards ISO-BUS - Jade Silent, simple, and on sale - a better motherboard 6 Slot (5'A" x8'A") MBS-061B Bare board $19.95 MBS-061K Kit $39.95 MBS-061A A&T $49.95 12 Slot (9 3 A" x 8%") MBS-121B Bare board $29.95 MBS-121K Kit $69.95 V1BS-121A A&T $89.95 18Slot(14'/j"x8%") WBS-181B Bare board $49.95 WBS-181K Kit $99.95 WBS-181A A&T $139.95 Mainframes MAINFRAME - Cal Comp Sys 12 slot S-100 mainframe with 20 amp power supply ENC-1 12105 Kit $379.95 ENC-112106 A&T $409.95 DISK MAINFRAME - N.P.C. Htilds 2 8" drives and a 12 slot S-100 system. Attractive metal cabinet with 12 slot motherboard & card cage, power supply, dual fails, lighted switch, and other professional I'calurvs ENS-112325 with 25 amp p.s $699.95 ■cle 179 on inquiry card. EXPANDORAM II - S D Systems 4 MHz RAM board expandable from 16K to 64K MEM-16630K 16K kit $275.95 MEM-32631K 32K kit $295.95 MEM-48632K 48K kit $315.95 MEM-64633K 64K kit $335.95 Assembled & tested add $50.00 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 $575.00 32K STATIC RAM - Jade 2 or 4 MHz expandable static RAM board uses 2114L's MEM-16151K 16K4MHzkit $169.95 MEM-32151K 32K 4 MHz kit $299.95 Assembled & tested add $50.00 16K STATIC RAM - Mem Merchant 4 MHz 16K static RAM board. IEEE S-100. bank selectable. Phantom capability, addressable in 4K blocks, "disable-able" in IK segments, extended addressing, low power MEM-16171A A&T $174.95 S-100 Disk Controller DOUBLE DENSITY - Cal Comp Sys 5'/i" and 8" disk controller, single or double density, with onboard boot loader ROM. and free CP-'M 2.2* and manual set. IOD-1300A A&T $369.95 VERSAFLOPPY II - SD Systems New double density controller for both 8" & 5'A" IOD-1160K Kit $339.95 IOD-1160A A&T $379.95 Disk Drives 8" DISK DRIVES Highly reliable double density floppy disk drives Shugart 801 R single sided, double density MSF-10801R SA-801R $425.00 Special Sale Price 2 for $790.00 Shugart 85 1R double sided, double density MSF-10851R SA-851R $595.00 Special Sale Price 2 for $1150.00 Siemens FDD100-8D2 single sided, double density MSF-201120 $385.00 Special sale price 2 for $750.00 Qume Datatrak 8 double sided, double density MSF- 750080 SA-851R compatible . . $599.95 Special sale price 2 for $1160.00 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 Kit $1395.00 5'A" Diskettes Box of 10 . . $22.00 8" Diskettes Box of 10 .... $24.00 » : ,hi CB-2 Z-80 CPU - S.S.M. 2 or 4 MHz Z-80 CPU board with prouision for up to 8Kof ROM or 4 K of RAM on board, extended addressing, IEEE S-100, front panel compatible. CPU-30300K Kit $239.95 CPU-30300A A&T $299.95 2810 Z-80* CPU - Cal Comp Sys 2/4 MHz Z-80A* CPU with RS-232C serial I/O port andon- board MOSS 2.2 monitor PROM, front panel compatible. CPU-30400A A&T $269.95 SBC-200 - SD Systems 4 MHz Z-80* CPU with serial & parallel I/O ports, up to 8K of on-board PROM, software programmable baud rate generator. IK of onboard RAM, Z-80 CTC. CPC-30200K Kit $339.95 CPC-30200A Jade A&T $399.95 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 Novation Cat Modem -Limited Quantity IOM-5200A List price $189.95 $125.00 D-CAT 300 baud, direct connect modem IOM-5201A Special sale price $169.95 AUTO-CAT Auto answer/origiate. direct connect IOM-5230A Special sale price $239.95 Place Orders Toll Free Continental U.S. Inside California 800-421-5500 800-262-1710 For Technical Inquires or Customer Service call: 213-973-7707 Computer Products 4901 W. Rosecrans, Hawthorne, Ca 90250 TKRMS of SALE: Cash, checks, credit cards, or Purchase Orders from qualified llrma and institutions. Minimum Order $15.00. California residents add 6% tax. Minimum shipping & handling charge $3.00. Pricing & avail ibil it y subject to change 16K Memory 8/$16.95 4116 300ns *" ALL MERCHANDISE 100% GUARANTEED CALL US FOR VOLUME QUOTES LS SERIES 74LS00 25 74LS163 .95 74LS01 .25 74LS164 .95 74LS02 .25 74LS165 .95 74LS03 .25 74LS166 2.40 74LS04 .25 74LS168 1.75 74LS05 .25 74LS169 1.75 74LS08 .35 74LS170 1.75 74LS09 .25 74LS173 .80 74LS10 .25 74LS174 .95 74LS11 .35 74LS175 .95 74LS12 .35 74LS181 2.15 74LS13 .45 74LS189 9.95 74LS14 1.00 74LS190 1.00 74LS15 .35 74LS191 1.00 74LS20 .25 74LS192 .85 74LS21 .35 74LS193 .95 74LS22 .25 74LS194 1.00 74LS26 .35 74LS195 .95 74LS27 .35 74LS196 .85 74LS28 .35 74LS197 .85 74LS30 .25 74LS221 1.20 74LS32 .35 74LS240 1.85 74LS33 .55 74LS241 1.85 74LS37 .55 74LS242 1.85 74LS38 .35 74LS243 1.85 74LS40 .25 74LS244 1.75 74LS42 .55 74LS245 2.85 74LS47 .75 74LS247 .76 74LS48 .75 74LS248 1.25 74LS49 .75 74LS249 .99 74LS51 .25 74LS251 1.30 74LS54 .35 74LS253 .85 74LS55 .35 74LS257 .85 74LS63 1.25 74LS258 .85 74LS73 .40 74LS259 2.85 74LS74 .45 74LS260 .65 74LS75 .50 74LS266 .55 74LS76 .40 74LS273 1.65 74LS78 .50 74LS275 3.35 74LS83 .75 74LS279 .55 74LS85 1.15 74LS280 1.98 74LS86 .40 74LS283 1.00 74LS90 .65 74LS290 1.25 74LS91 .89 74LS293 1.85 74LS92 .70 74LS295 1.05 74LS93 .65 74LS298 1.20 74LS95 .85 74LS352 1.55 74LS96 .95 74LS353 1.55 74LS107 .40 74LS363 1.35 74LS109 .40 74LS365 .95 74LS112 .45 74LS366 .95 74LS113 .45 74LS367 .70 74LS114 .50 74LS368 .70 74LS122 .45 74LS373 1.85 74LS123 .95 74LS374 1.80 74LS124 2.99 74LS377 1.45 74LS125 .95 74LS378 1.18 74LS126 .85 74LS379 1.35 74LS132 .75 74LS385 1.90 74LS136 .55 74LS386 .65 74LS137 .99 74LS390 1.90 74LS138 .75 74LS393 1.90 74LS139 .75 74LS395 1.65 74LS145 1.20 74LS399 1.70 74LS147 2.49 74LS447 .37 74LS148 1.35 74LS490 1.95 74LS151 .75 74LS668 1.69 74LS153 75 74LS669 1.89 74LS154 2.35 74LS670 2.20 74LS155 1.15 74LS674 9.65 74LS156 .95 74LS682 3.20 74LS157 .75 74LS683 2.30 74LS158 .75 74LS684 2.40 74LS160 .90 74LS685 2.40 74LS161 .95 74LS688 2.40 74LS162 .95 74LS689 2.40 7400 SERIES 7400 .19 74128 .55 7401 .19 74132 .45 7402 .19 74136 .50 7403 .19 74141 .65 7404 .19 74142 2.95 7405 .22 74143 2.95 7406 .22 74144 2.95 7407 .22 74145 .60 7408 .24 74147 1.75 7409 .19 74148 1.20 7410 .19 74150 1.35 7411 .25 74151 .65 7412 .30 74152 .65 7413 .35 74153 .55 7414 .55 74154 1.40 7416 .25 74155 .75 7417 .25 74156 .65 7420 .19 74157 .55 7421 .35 74159 1.65 7422 .29 74160 .85 7423 .29 74161 .70 7425 .29 74162 .85 7426 .29 74163 .85 7427 .29 74164 .85 742B .45 74165 .85 7430 .19 74166 1.00 7432 .29 74167 1.95 7433 .45 74170 1.65 7437 .29 74172 5.95 7438 .29 74173 .75 7440 .19 74174 .89 7442 .49 74175 .89 7443 .65 74176 .89 7444 .69 74177 .75 7445 .69 74178 1.15 7446 .59 74179 1.75 7447 .69 74180 .75 7448 .69 74181 2.25 7450 .19 74182 .75 7451 .23 74184 2.00 7453 .23 74185 2.00 7454 .23 74186 18.50 7460 .23 74190 1.15 7464 .39 74191 1.15 7465 .39 74192 .79 7470 .35 74193 .79 7472 .29 74194 .85 7473 .34 74195 .85 7474 .35 74196 .79 7475 .49 74197 .75 7476 .35 74198 1.35 7480 .59 74199 1.35 7481 1.10 74221 1.35 7482 .95 74246 1.35 7483 .50 74247 1.25 74B4 .50 74248 1.85 7485 .65 74249 1.95 7486 .35 74251 .75 7489 4.95 74259 2.25 7490 .35 74265 1.35 7491 .40 74273 1.95 7492 .50 74276 1.25 7493 .49 74279 .75 7494 .65 74283 2.00 7495 .55 74284 3.75 7496 .70 74285 3.75 7497 2.75 74290 .95 74100 1.00 74293 .75 74107 .30 74298 .85 74109 .45 74351 2.25 74110 .45 74365 .65 74111 .55 74366 .65 74116 1.55 74367 .65 74120 1.20 74368 .65 74121 .29 74376 2.20 74122 .45 74390 1.75 74123 .55 74393 1.35 74125 .45 74425 3.15 74126 .45 74426 .85 74490 2.55 74S00 SERIES 74S00 74S02 74S03 74S04 74S05 74S08 74S09 74S10 74S11 74S15 74S20 74S22 74S30 74S32 74S37 74S38 74S40 74S51 74S64 74S65 74S74 74S85 74S86 74S112 74S113 74S114 74S124 74S132 74S133 74S134 74S135 74S138 74S139 74S140 74S151 74S153 74S157 74S158 74S161 74S162 .69 2.39 1.44 1.59 1.98 1.50 2.77 1.24 .98 .69 1.48 1.08 1.25 1.45 1.19 1.19 1.19 1.45 2.85 3.70 74S163 74S168 74S169 74S174 74S175 74S181 74S182 74S188 74S189 74S194 74S195 74S196 74S197 74S201 74S225 74S240 74S241 74S251 74S253 74S257 3.75 4.65 5.44 1.09 1.09 4.47 2.95 3.95 14.95 2.95 1.89 4.90 4.25 14.95 8.95 3.98 3.75 1.90 7.45 1.39 74S258 74S260 74S274 74S275 74S280 74S287 74S288 74S289 74S301 74S373 74S374 74S381 74S387 74S412 74S471 74S472 74S474 74S482 74S570 74S571 1.49 1.83 19.95 19.95 2.90 4.75 4.45 6.98 6.95 3.45 3.45 7.95 5.75 2.98 9.95 16.85 17.85 15.60 7.80 7.80 T.V. CIRCUITS MC1330 1.89 MC1350 1.29 MC1358 1.79 LM380 1.29 LM386 1.50 LM565 .99 LM741 .29 LM1310 2.90 LM1800 2.99 LM1889 2.49 MISC. 8T26 1.69 3242 9.95 8T28 2.49 AY5-1013 3.95 8T95 .99 TR1602 4.95 8T96 .99 IM6402 7.95 8T97 .99 1771 24.95 8T98 .99 1791 36.95 1488 .99 UPD765 39.95 1489 .99 8272 39.95 DM8131 2.95 1793 49.95 CMOS 74C00 .35 74C373 2.75 4018 74C02 .35 74C374 2.75 4019 74C04 .35 74C901 .80 4020 74C08 .35 74C902 .85 4021 74C10 .35 74C903 .85 4022 74C14 1.50 74C905 10.95 4023 74C20 .35 74C906 .95 4024 74C30 .35 74C907 1.00 4025 74C32 .50 74C908 2.00 4026 74C42 1.75 74C909 2.75 4027 74C48 2.10 74C910 9.95 4028 74C73 .65 74C911 10.00 4029 74C74 .85 74C912 10.00 4030 74C76 .80 74C914 1.95 4034 74C83 1.95 74C915 2.00 4035 74C85 1.95 74C918 2.75 4040 74C86 .95 74C920 17.95 4041 74C89 4.50 74C921 15.95 4042 74C90 1.75 74C922 5.95 4043 74C93 1.75 74C923 5.95 4044 74C95 1.75 74C925 6.75 4046 74C107 1.00 74C926 7.95 4047 74C150 5.75 74C927 7.95 4049 74C151 2.25 74C928 7.95 4050 74C154 3.25 74C929 19.95 4051 74C157 1.75 74C930 19.95 4053 74C160 2.00 4000 .35 4060 74C161 2.00 4001 .35 4066 74C162 2.00 4002 .25 4068 74C163 2.00 4006 .95 4069 74C164 2.00 4007 .29 4070 74C165 2.00 4008 .95 4071 74C173 2.00 4009 .45 4072 74C174 2.25 4010 .45 4073 74C175 2.25 4011 .35 4075 74C192 2.25 4012 .25 4076 74C193 2.25 4013 .45 4078 74C195 2.25 4014 .95 4081 74C200 5.75 4015 .95 4082 74C221 2.25 4016 .45 4085 4017 1.15 4086 .95 4093 .45 4099 .95 14409 .95 14410 1.15 14411 .35 14412 .75 14419 .35 4502 1.65 4503 .65 4508 .80 4510 .95 4511 .45 4512 2.95 4514 .85 4515 .95 4516 1.25 4518 .75 4519 .85 4520 .85 4522 .95 4526 .95 4527 .55 4528 .55 4531 .95 4532 .95 4538 1.45 4539 .75 4543 .40 4555 .35 4556 .35 4581 .30 4582 .30 4584 .30 4585 .30 4702 .95 4724 .30 80C07 .30 80C95 .30 80C96 .95 80C97 .95 80C98 .95 1.95 8.95 8.95 9.95 12.95 2.95 .95 .65 1.95 .95 .95 .95 1.25 2.25 1.55 1.25 1.25 1.25 1.25 1.25 1.95 1.25 .95 1.95 1.95 1.95 2.70 .95 .95 1.95 1.95 .95 .95 12.95 1.50 .95 .85 .95 .95 1.20 DIP SWITCHES 4 position .85 5 position .90 6 position .90 7 position .95 8 position .95 CONNECTORS TRANSISTORS PN2222 2N3904 2 N 3906 2N3055 IN4148 IN 4004 10/1.00 10/1.00 10/1.00 .79 100/8.99 100/8.99 100/8.99 10/6.99 25/1.00 10/1.00 RS232MALE RS232 FEMALE RS232 HOOD S-100ST S-100WW 3.25 3.75 1.25 3.95 4.95 LINEAR VOLTAGE REG'S 7805T 7808T 7812T 7615T 7824T .89 .99 .89 .99 .99 7905T 791 2T 7915T 7924T .99 .99 1.19 1.19 7805K 7812K 7815K 1.39 1.39 1.39 7905K 7912K 1.49 1.49 78L05 78L12 78L15 .69 .69 .69 79L05 79L12 79L15 .79 .79 .79 LM309K LM317T LM317K 1.49 1.95 3.95 LM323K LM337K 4.95 3.95 T = TO-220 K = TO-3 L = TO-92 LM301V .34 LM741V .29 LM308V .98 LM747 .79 LM309K 1.49 LM748V .59 LM311 .64 LM1310 2.90 LM317T 1.95 MC1330 1.89 LM317K 3.95 MC1350 1.29 LM318 1.49 MC1358 1.79 LM323K 4.95 LM1414 1.59 LM324 .59 LM 1458V .69 LM337K 3.95 LM1488 1.39 LM339 .99 LM1489 1.39 LM377 2.29 LM1B00 2.99 LM380 1.29 LM1889 2.49 LM386V 1.50 LM3900 59 LM555V .39 LM3909V .98 LM556 .69 LM3914 3.95 LM565 .99 LM3915 3.95 LM566V 1.49 LM3916 3.95 LM567V 1.29 75451V .39 LM723 .49 75452V .39 LM733 .98 75453V .39 mm VISA" ll master charge ■ * — -^— ~^^r.^fj JDR MICRODE VICES, INC. 1101 South Winchester Blvd. San Jose, California 95128 800-538-5000 800-662-6263 (Calif.) 408-247-4852 T=TO-220 V=8PIN K=TO-3. TERMS: For shipping Include $2.00 lor UPS Ground; $3.00 for UPS Blue Label Aln $10.00 minimum order. Bay Area Residents add 6Vi% sales tax Calif. Residents add 6% sales tax. We reserve the right to limit quantities and Circle 181 on inquiry card. 4K STATIC RAMS 8/18.95 2114 LOW POWER 450ns ALL MERCHANDISE 100% GUARANTEED CALL US FOR VOLUME QUOTES 8200 6800 Z80 8202 8205 8212 8214 8216 8224 8226 8228 8237 8238 8243 8250 8251 8253 8253-5 8255 8255-5 8257 8259 8272 8275 8279 8279-5 8282 8283 8284 8286 8287 8288 8289 45.00 3.50 1.95 3.90 1.85 2.50 1.85 4.95 19.95 4.95 4.50 14.95 5.50 9.85 9.85 5.25 5.25 9.00 7.00 39.95 29.95 10.50 10.50 6.65 6.65 5.80 6.65 6.65 25.00 49.95j IC SOCKETS 1-100 100pcs 8 pin ST 1 14 pin ST 1 16 pin ST lis pin ST 1 20 pin ST .22 pin ST |24 pin ST |28pinST 1 40 pin ST .13 .15 .17 .20 .29 .30 .30 .40 .49 .11 .12 .13 | .18 .27 I 27 .27 .32 .39 ST = SOLDERTAIL 1 pin WW 1 14 pin WW 16 pin WW 1 18 pin WW 1 20 pin WW 1 22 pin WW 124 pin WW 1 28 pin WW 1 40 pin WW .59 .69 .69 .99 1.09 1.39 1.49 1.69 1.99 .49 .52 .58 .90 .98 1.28 1.35 1.49 1.80 6800 6.95 6802 11.95 6809 37.95 6810 4.60 6820 4.95 6821 4.95 6828 9.95 6834 16.95 6840 14.95 6843 42.95 6844 44.95 6845 29.95 6847 15.95 6850 4.75 6852 5.75 6860 10.95 6862 11.95 6871 25.95 6875 6.95 6880 2.95 6502 6502 6502A 6504 6505 6520 6522 6532 6551 6.95 12.95 6.95 8.95 4.95 9.95 14.95 14.95 Z80 Z80A Z80B Z80-PIO Z80A-PIO Z80-CTC Z80A-CTC ZB0-DART Z80A-DART Z80-DMA Z80A-DMA Z80-SIO/0 Z80A-SIO/0 Z80-SIO/1 Z80A-SIO/1 Z80-SIO/2 Z80A-SIO/2 Z80-SIO/9 Z80A-SIO/9 8.95 9.95 19.95 6.50 8.60 6.50 8.65 15.25 18.75 17.50 27.50 23.95 28.95 23.95 28.95 23.95 28.95 17.95 22.95. MPU'S 8035 8039 8080A 8085 8086 8088 8155 8156 8185 8185-2 8741 8748 8755 16.95 19.95 3.95 12.95 99.95 39.95 11.95 11.95 29.95 39.95 39.95 69.95 49.95 BEFORE YOU BUY CALL JDR FOR THE BEST PRICE. 800-662-6233 (CALIFORNIA RESIDENTS) SEPTEMBER SPECIALS 4116 4116 150ns 200ns 2708 2716 Intel and NEC 2732 Intel 2532 Ti and Hitachi NEC 2.99 5.95 16.50 Z80A Z80A Z80A 8251 A UPD765 LM323K LS240 LS241 LS244 PIO SIO/1 Intel (8272) 3.50ea 8 for 19.95 8 for 17.50 8 for 2.75ea 8 for 5.50ea 8for15.95ea 19.95ea 6.00ea 6.00ea 15.00ea 4.75ea 35.00ea 10 for3.00ea LS SPECIALS 99 LS245 1.90 99 LS373 .99 99 SL374 1.75 WW = WIREWRAP (Sale Ends September 30, 1981) LEDS Jumbo Red 10/1.00 Jumbo Green 6/1.00 Jumbo Yellow 6/1.00 5082-7760 .43'CC .79 MAN74.3'CC .99 MAN72.3'CA .99 DYNAMIC RAMS 4027 (250ns) 2.50 4116-150 (150ns) 8/21.95 4116-200 (200ns) 8/19.95 4116-300 (300ns) 8/16.95 k 4164 (200ns) CALL 100pcs 2.00 2.65 2.35 2.00 CALL, STATIC RAMS 100pcs 2101 (450ns) 1.95 1.85 2102-1 (450ns) .89 .85 21L02-1 (LP) (450ns) 1.29 1.15 2111 (450ns) 2.99 2.49 2112 (450ns) 2.99 2.79 2114 (450ns) 8/18.95 2.25 2114L-2 (LP) (200ns) 8/22.95 2.45 2114L-3 (300ns) 8/21.95 2.45 2114L-4 (LP) (450ns) 8/18.95 2.25 4044-4 (450ns) 3.49 3.25 4044-3 (300ns) 3.99 3.75 TMM2016 (200ns) CALL CALL MB6116 (200ns) CALL CALL LP = LOW POWER EPROMS Bpcs 1702 256x8 ( 1us) 4.95 4.50 2708 1024x8 (450ns) 3.95 3.50 2716 (5v) 2048 x 8 (450ns) 6.95 5.95 2758 (5v) 1024x8 (450ns) 9.95 8.95 2716-1 (5v) 2048 x 8 (350ns) 12.95 11.95 TMS2716 2048 x 8 (450ns) 9.95 8.95 TMS2532 (5v) 4096 x 8 (450ns) 21.95 19.95 2732 (5v) 4096 x 8 (450ns) 17.95 16.95 PROMS 74S188 74S287 74S288 74S387 74S471 74S472 74S474 74S570 74S571 (82S23) (82S129) (82S123) (82S126) (82S147) (82S141) (82S130) (82S131) OC TS TS OC TS TS TS OC TS 32x8 256x4 32x8 256x4 256x8 512x8 512x8 512x4 512x4 3.95 4.75 4.45 5.75 9.95 16.85 17.85 7.80 7.80 JDR MICRODEVICES, INC. 1101 South Winchester Blvd. San Jose, California 95128 800-538-5000 800-662-6263 (Calif.) 408-247-4852 TERMS: For shipping Include $2.00 (or UPS Ground; $3.00 lor UPS Blue Label Air, $10.00 minimum order. Bay Area Residents add 6'/i% sales tax Calif. Residents add 6% sales tax. We reserve the right to limit quantities and substitute manufacturer. Prices subject to change without notice. Circle 181 on inquiry card. WHAT'S NEW FROM CONSUMER COMPUTERS Consumer Computers announces it's lowest prices ever. Apple Cards and Hardware 16K Ram Card by CCI 130 Language System w/Pascal 379 Silentype Printer w/lnterface card 349 Hayes Micromodem II 299 Novation Apple-Cat II 339 Videx uideoterm 80 column w/graphics 269 Z-80 Softcard by Microsoft 299 16K RamCard by Microsoft 159 ABT Numeric Keypad (old or new kybrd) 110 ALF 3 voice Music Card 239 ALF 9 voice Music Card 169 Heuristics Speechlink 2000 259 Alpha Syntauri Keyboard System 1399 Corvus 10MB Winchester Disk system CALL Lazer Lower Case Plus+ 55 Micro-Sci Disk Drives (A-40 & A- 70) CALL SSM AIO Serial/Parallel card A&T 189 Sup-R- Terminal 80 Column Card 329 SVA 2VX4 Megabyter 8" disk controller 589 SVA 2+2 Single Den. 8" disk controller 345 Versawriter Digitizer Pad 229 Digisector Camera interface 299 ThunderCtack Plus 119 Symtec Hi-Res Light Pen 210 Integer or Applesoft Firmwave card 145 Graphics Tablet 619 Parallel Printer interface card 135 Hi-Speed Serial interface card 135 Smarterm 80 column card 299 Joystick by Keyboard Co 45 Music System (16 Voices) 479 A/D + D/A interface 289 Expansion Chassis 599 lntrol/X-10 controller card 169 Clock/Calendar card 225 CPS Multi-function card 189 Supertalker SD-200 239 Romplus+ Card 135 Romwriter Card 149 Clock/Calendar Module 99 GP1B IEEE-488 Card 249 Asynchronous Serial Interface Card 129 Centronics Parallel Interface Card 99 Arithmetic Processor Card 299 We carry all CCS cards, please call for best prices. Apple II Entertainment Software (Top Ten) Raster Blaster 29 Alien Rain 23 Hungry Boy 24 Adventure by Microsoft 27 Sargon II Chess 32 Pulsar II 29 Space Eggs 29 Flight Simulator 34 Cosmos Mission (Space Invaders) 24 Worlds Greatest Black Jack game 40 WE OFFER HUNDREDS OF SOFT- WARE GAMES. PLEASE CALL OR WRITE FOR A LIST. VIDEO TAPES WE SELL HUNDREDS OF FEATURE FILMS ON VHS AND BETA VIDEO TAPE. CALL OR WRITE FOR A PRICE LIST. The versatile Apple Computer NOW ONLY 16K $1025 48K NOW ONLY $1129 64K & NOW ONLY $1249 *16K Ram Card installed on 64K. TOLL FREE ORDER LINE 800-854-6654 California & outside continental U.S. (714) 698-8088 International Telex 695-000 Beta CCMO APPLE /// These systems come complete with the information analyst software package and a video monitor of your choice. 96K FOR ONLY $3495 128K FOR ONLY $3995 DISK/// 450 SILENTYPE/// 329 AVAILABLE NOW! ■ ■ ■ L^g^B | 1 il NEC MICROCOMPUTER PC-8001A 32K RAM COMPUTER CALL PC-8012A I/O UNIT W/32K RAM CALL PC -8031A DUAL MINI-DISK DRIVE UNIT CALL Please write for more information about the NEC computer. \ With Controller Without Controller Apple Disk Drives $519 $439 Solution Software the Apple U Visicalc 3.3 169 CCA Data Management 85 DB Master 169 WordStar (Apple 80 co. version) 299 Super Text n 139 Desktop Plan II 169 Applewriter 65 Infotory 225 Landlord Apt. Mngmt 649 Stock Tracker by H&H 175 Easywriter 225 ASCII Express 59 Peachtree Business Software CALL Applesoft Compiler 185 Visiterm 129 Visitrend/Visiplot 219 Real Estate Analyzer 89 Tax Preparer 99 DOS Toolkit 65 Tax Planner 99 Dow Jones Portfolio Evaluator 45 Dow Jones News & Quotes Reporter 85 Apple Fortran 165 Apple Pilot 129 Controller Gen. Bus. System 499 The Analyzer Dakin 5 : . • 519 Music Theory 45 Circle 94 on Inquiry card. WHAT'S NEW FROM CONSUMER COMPUTERS Buying Mail Order saves time, money and energy! Atari Personal Computer ATARI 800 16K $749 ATARI 400 16K $349 410 Program Recorder 65 810 Disk Drive 449 815 Dual Disk Drive (Dbl. Den.) 1295 820 40 Col. Impact Printer 349 822 Thermal Printer 349 825 80 Col Impact Printer (Cent. 737) 699 830 Acoustic Modem 159 850 Interface Module 159 Atari Light Pen 65 16K Ram Memory Module 149 16K RAM Memory Module (by ConComp) 89 Ohio Scientific Challenger Computer 4P IP MOD II $549 $399 Exidy Sorcerer II --"■*■» We have the Sorcerer II in stock at unbeatable prices. Available in 16K, 32K & 48K models. Please Call for Price. S-100 Expansion Unit 429 Word Processing Pac 179 Development Pac 89 PMC-80 Micro Computer $599 16K Compatible with TRS-80 Model and software! hardware S-100 Quality S-100 cards available now at incredibly low prices. Assm & Kit Tested CALIFORNIA COMPUTER SYSTEMS Z-80 CPU 2810 n/a 229 64K Dynamic Ram board n/a 499 16K Static Ram 2 MHz n/a 249 16K Static Ram 4 MHz n/a 299 Dbl. Density Floppy Disk Controller n/a 299 12 Slot S-100 Mainframe n/a 349 SSM Z-80 CPU CB-2 219 104 2 par. & 2 ser. 1/0 board 189 VB-3 80 * 24 Video board 329 VB-3 80 « 48 Video board 369 VB-2 I/O Mapped video board 64 » 16 .... 159 PB1 PROM Prgmmr & EPROM board .... 139 SD SYSTEMS EXPANDORAM I (2MHz Uses 4116 16K dynamic RAM and is expandable 32K to 64K 48K 64K 16K 32K 48K 64K EXPANDORAM II (4MHz Uses 4116 or 4164 dynamic RAM, is expandable to 64K or 256K respectively. VERSAFLOPPY I Disk controller VERSAFLOPPY II Disk controller SBC100 2.5 MHz Z-80 w/I/O SBC-200 4 MHz Z-80 w/l/O PROM 100 EPROM programmer We will beat any currently advertised price on S-100 boards . 240 . 255 .275 . 295 . 250 . 269 . 289 . 305 250 299 299 299 210 279 249 379 429 219 199 310 325 345 365 319 339 359 375 319 369 369 369 279 TOLL FREE ORDER LINE 800-854-6654 California & outside continental U.S. (714) 698-8088 International Telex 695-000 Beta CCMO Use your Mastercard, Visa, American Express, Carte Blanche, Diners Club to charge your order phone. Open 7 days. Video Monitors Amdek/Leedex Video 100 12" B&W 139 Amdek (Hitachi) 13" Cobr 359 NEC 12" Green Phospher Screen CALL NEC 12" RGB Hi-Res Color CALL Panasonic 13' Color 449 Sanyo 9" B&W 185 Sanyo 9" Green Phospher Screen CALL Sanyo 12" B&W 269 Sanyo 12" Green Phospher Screen 285 Sanyo 13" Color w/excellent resolution 449 PRINTERS Epson /~* \ 1 MX-80 \ ,>/"%■ ■ t Paper Tiger IDS-460 $949 Anadex 9500/9501 w/ 2K Buffer 1299 C. Itoh Starumter 25 CPS 1499 C. Itoh Starwriter 45 CPS 1899 Espon MX-70 CALL Epson MX-80 F/T CALL Paper Tiger 1DS-445 699 Paper Tiger IDS-460 949 Paper Tiger 1DS-560 1249 Silentype w/ Apple II interface card 349 Qume Sprint 5/45 2495 Silentype w/apple II Interface $349 How to Order: Ordering Information: Phone orders using VISA, MASTERCARD, AMERICAN EXPRESS, DINERS CLUB, CARTE BLANCHE, bank wire transfer, cashiers or certified check, money order, or personal check {allow ten days to clear.) Unless prepaid with cash, please add 5% for shipping, handling and insurance minimum $5.00). California residents add 6% sales tax. We accept COD's. PO's accepted from Educational Institutions. All equipment is subject to price change and availability without notice. All equipment is new and complete with manufacturer's warranty. Showroom prices may differ from mail order advertisement. Send Orders to: GOmgQaDODQD 3 G®ncDpaO®[ Mail Order 8314 Parkway Drive La Mesa, California 92041 Circle 94 on inquiry card. CALL US TODAY FOR SPECIAL SYSTEM PACKAGE PRICES . . . Now is the time to buy a complete system of your choice. . . • CROMEMCO SYSTEM 2 • DYNABYTE • NORTHSTAR • SUPERBRAIN Complete with printer and software. READY TO USE!!! Participate in our expansion sale. MiniMicroMart is moving to larger quarters to serve you with a larger staff and with the largest inventory of systems and peripherals. MiniMicroMart, Inc. 943 W. Genesee St. Syracuse, New York 13204 (315)422-4467 478 BYTE September 1981 Circle 241 on inquiry card. WE ARE MOVING TO LARGER QUARTERS! Thank you . . . ... for making our expansion possible and for helping make us the leading distributor of microprocessor systems, terminals and printers. We are showing our appreciation by producing a special catalog with thousands of items at greatly reduced prices. Call or write today. Help us move our inventory before we have to move it. MiniMicroMart, Inc. 943 W. Genesee St. Syracuse, New York 13204 (315)422-4467 Circle 242 on Inquiry card. Bra September i 981 479 1858 EVERGREEN • DUARTE, CALIFORNIA 91010 • TELEPHONE (213) 357-50C V* JUST WRAP KIT Just Wrap tool for 1* daisy chain wiring. Tool strips as it wraps and cuts. o Includes one 50 foot spool of wire. '# Part No. Description Price jw-r Just Wrap Tool $14.95 JWK-6 Tool w/4 Spools and JUW1 24.95 R-JW* 50 Ft. Replacement Wire 3.49 JUW-1 Unwrapping Tool 3.49 •Specify Color: Red, Blue, White or Yellow. Part No. WSU30 WSU30M Regular Modified Wrap Wrap HAND WRAP TOOL Description Price Regular $6.95 Modified 7.95 TERMINALS VWM • .025 (0,63mm) Square Post • 3 Level Wire- Wrapping • Gold Plated 25 PER PKG. WWT-1 WWT-2 WWT-3 WWT-4 INS 1 Description Slotted Terminal Single Sided Terminal IC Socket Term. Double Sided Terminal Insertion Tool for above Price $4.98 2.98 4.98 1.98 2.49 SOCKET WRAP ID •••••••••••• n )< I5 I6 I7 18 19 20 21 22 23 2< Wrap-ID 12 It 10 ? « 7 i 5 < ' 2 I Slipped onto socket before wrapping to identify pins. Bulk Bulk Part # Price Price Part i Price Price 1410 1.49/10 5.50/100 22ID 1.49/5 5.95/50 16ID 1.49/10 5.95/100 24ID 1.49/5 5.95/50 18ID 1.49/10 5.00/50 28ID 1.49/5 6.50/50 20ID 1.49/5 5.00/50 40ID 1.49/5 5.00/25 $K> PRODUCTS _ «j§P.C.B. ttttte ftSft$SJ&! TERMINAL iaiar^ strips T^H flftk' The TS strips provide positive screw activated clamping action, accom- modate wire sizes 14-30 AWG (1,8-0, 25mm . Pins are solder plated copper, .042 in ch (1mm) diameter, on .200 inch (5mm) centers. Part No. Description Price TS- 4 4-Pole $1.69 TS- 8 8-Pole 2.59 TS-12 12-Pole 3.49 TS6MD 2-Pole Interlocking 3/1.79 DESOLDERING PUMP Easy one hand operation. Rugged all metal construction. Replaceable TEFLON® Tip. Self cleaning on each stroke. Suction precisely regulated for reliable desoldering without damage to delicate circuitry. DSPI Desoldering Pump LOGIC PROBE Compatible with all logic families us- ing a 4 to 15V power supply. Thresholds automatically programm- ed. Visual indication of logic levels to show high, low, bad level or open cir- cuit logic pulses. • 10 N sec. pulse responses • 120 K input impedence. • Automatic resetting memory. • Includes tip with protective cap & coiled cord. PRB-1 $36.95 LOGIC PULSER Superimposes a pulse train (20 pps) or a single pulse onto the circuit node under test without un-soldering IC's. • Automatic polarity sensing • 2 us pulse width • Finger tip push button actuated • Includes tip with protective cap & coiled cord. PSL-1 $48.95 VACUUM VISE Unique vacuum-based light duty vise for precision handling of small components and assemblies. Rugged ABS construction. 1 V2" (32mm)' travel for maximum versatility, features screw lugs for perm installation. VV1 Vacuum Vice $3.49 HOBBY- WRAP TOOL BW263 Auto-Indexing Anti-Overwrap Modified Wrap Part No. Description BW2630 Tool BT30 #30 Bit (not incl.) BT2628 #28 Bit (not incl.) BC1 Batteries & Charger $19.85 3.95 7.95 14.95 INSERTION/EXTRACTION TOOLS Part No. INS1416 MOS1416 MOS2428 MOS40 EX1 EX2 Price $3.49 Description 14-16 pin Inserter 14-16 pin MOS Safe Inserter 24-28 pin MOS Safe Inserter 40 pin MOS Safe Inserter 14-16 pin IC Extractor 24-40 pin IC Extractor WK-7 IC f -INSERTION K lftj|?5.l— Complete IC In- serter/ Extractor K Individual Corn- el h ponents (listed H. ~ above) $22.95 7.95 7.95 7.95 1.49 7.95 IC DISPENSER Allows IC's to be dis- pensed from their tube 1 at a time and picked up by insertion tools above. • Dispenses 8-42 pin IC's • Compatable with all IC carrying tubes • Use with WK7 for MOS - safe insertion. • Part No. Description MDD1 1 Chan. Dispenser MDD5 5 Chan. Dispenser MDD10 10 Chan. Dispenser * * *No Discount. Circle 281 on inquiry card. LL FREE ORDERING NUMBER 1(800) 423-7144 IDC CONNECTORS RIGHT ANGLE HEADERS SOLDER TAIL WIRE WRAP Size Part No. Price IDH10SRB $1.20 IDH20SRB 1.90 IDH26SRB 2.75 IDH34SRB 3.75 IDH40SRB 3.75 IDH50SRB 4.75 Part No. IDH10WRB IDH20WRB IDH26WRB IDH34WRB IDH40WRB IDH50WRB Price S2.60 4.15 5.35 6.25 7.35 9.20 .1" Spacing. Mounts on PC Board & Mates with IDS Socket below. Ejector Bars ■ 4/1.00. * f N t 25 PIN 'D" CONNECTORS Solder Style Male Female Cover Part No. DB25P DB25S DB25C Price $2.95 3.95 1.50 IDC Style Male IDB25P 6.25 Female IDB25S 6.60 Cover IDB25C 1.60 Solder Style solders onto cable, IDC Style crimps onto cable with vise. 9, 15, 37 and 50 pin available also. WIRE WRAP WIRE #30 Wire Wrap Wire Length 100/Bag 500/Bag 1K/Bag 2.5" $1.38 $3.94 $6.81 3.0" 1.43 4.25 7.46 3.5" 1.51 4.57 8.11 4.0" 1.56 4.88 8.73 4.5" 1.63 5.21 9.39 5.0" 1.69 5.54 10.04 5.5" 1.74 5.92 10.69 5.0" 1.82 6.23 11.34 3.5" 2.11 7.08 12.99 7.0" 2.19 7.44 13.68 7.5" 2.29 7.78 14.40 3.0" 2.35 8.12 15.10 3.5" 2.40 8.46 15.80 9.0" 2.46 8.92 16.51 3.5" 2.53 9.15 17.22 10.0" 2.63 9.58 17.91 Ml lengths are overall, including 1" strip on each end. Choose from colors; Red, 3lue, Black, Yellow, White, Green, Drange, and Violet. EDGE CARD CONNECTORS Size Part No. Price 10 IDE10B $3.95 20 IDE20B 4.35 26 IDE26B 5.00 34 IDE34B 6.05 40 IDE40B 6.90 50 IDE50B 7.50 .1" Spacing. Crimps onto cable with ordinary vise & mates with standard .062" Card Edge. I w CABLE PLUGS Size 14 16 24 40 Part No. IDP14B IDP16B IDP24B IDP40B Price $1.45 1.65 2.50 4.15 .1" Spacing. Crimps onto cable with ordinary vise & plugs into standard IC Socket. WIRE WRAP SUPPLIES Size Part No. ICN083WBSG Each .44 Tube 08 52x .39 = = $20.28 14 ICN143WBSG .53 30x .46 = = $13.80 16 ICN163WBSG .58 26x .50 = = $13.00 18 ICN183WBSG .78 23x .68 = = $15.64 20 ICN203WBSG 1.00 21 X .85 = = $17.85 22 ICN224WBSG 1.07 19x .92 = = $17.48 24 ICN246WBSG 1.09 17x1.09 = = $15.98 28 ICN286WBSG 1.43 15x1.23 = = $18.45 40 ICN406WBSG 1.85 10x1.60 = = $16.00 Selective Plating provides gold in contact where it counts. 3-level wrap. Save by buy- ing sockets by the tube. All gold available at VaC/pin extra charge. ' * " No Discount _ ^ W Solid Color Color Coded ^{^l Size 10 ft. 100 ft. 10 ft. 100 ft. \j 10 2.90 17.00 4.00 30.00 14 3.40 23.80 5.00 42.00 16 3.70 27.20 5.60 48.00 20 4.40 34.00 7.00 60.00 24 5.00 40.80 8.00 72.00 26 5.40 44.20 8.60 78.00 34 6.80 57.80 11.00 102.00 40 7.80 68.00 13.00 120.00 50 9.50 85.00 16.00 150.00 SOCKETS 1 Size Part No. Price 10 IDS10B $1.88 20 IDS20B 2.75 26 IDS26B 3.50 34 IDS34B 4.50 40 IDS40B 5.40 50 IDS50B 6.50 .1" Spacing. Crimps onto cable with ordinary vise & mounts to header sold above. WIRE KITS Kit No. 1 - $9.95 250 3" 100 4%" 200 3%" 100 5" 100 4" 100 Kit No. 2 - $24.95 6" 250 2%" 250 5" 500 3" 100 5 1 / 2 " 500 3'/ 2 " 100 6" 500 4" 100 6%" 250 4Va" 100 Kit No. 3 - $34.95 7" 250 2%" 500 4Va" 500 3" 500 5" 500 3'/2" 500 5 1 / 2 " 500 4" 500 Kit No. 4 - $59.95 6" ■ 500 2%" 1000 AVz" 1000 3" 1000 5" ' 1000 3%" 1000 5V2" 1000 4" 1000 6" ORDERING INFORMATION 'repaid orders over $50 shipped prepaid via JPS. All others add $3.00 for handling. VISA, vIC, COD's and open account orders will be ;harged freight. $15 minimum order. $100 ninimum open account order. DISCOUNT SCHEDULE Order Amount Discount and the name of $15 - 99 Net this magazine must be men- 100- 199 less 10% tioned at time of order to get 200 - 499 less 15% discount. Discount applies 500 - 999 less 20% on all items except as noted, 1000 up less 25% "No Discount." Circle 281 on inquiry card. 7400 TTFSo? SN7400N SN7401N SN7402N SN7403N SN7404N SN7405N SN7406N SN7407N SN7408N SN7409N SN7410N SN7411N SN7412N SN7413N SN7414N SN7416N SN7417N SN7420N SN7421N SN7422N SN7423N SN7425N SN7426N SN7427N SN7429N SN7430N SN7432N SN7437N 5N7438N SN7439N SN7440N SN7441N SN7442N SN7443N SN7444N SN7445N SN7446N SN7447N SN7448N SN7450N SN7451N SN7453N SN7454N SN7459N SN7460N SN7470N SN7472N SN7473N SN7474N SN7475N SN7476N SN747dN SN7480N SN7482N SN7483N SN7485N SN7486N SN7489N SN7490N SN7491N SN7492N SN7493N SN7494N SN7495N SN7496N SN7497N SN74100N SN74107N SN74109N SN74116N SN74121N SN74122N 4.60 .49 1.75 .39 1.95 .29 SN74123N SN74125N SN74126N SN7412BU SN74132N SN74136N SN74139N SN74141N SN74142N SN74143N SN74144N SN74145N SN74147N SN74148N SN74150N SN74151N SN74152N SN74153N SN74154N SN74155N SN74156N SN74157N SN74158N SN74160N SN74161N SN74162N SN74163N SN74164N SN74165N SN74166N SN74167N SN74170N SN74172N SN74173N SN74174N SN74175N SN74176N SN74177N SN74179N SN74180N SN74181N SN74182N SN74184N SN74185N SN74186N SN74188N SN74190N SN74191N SN74192N SN74193N SN74194N SN74195N SN74196N SN74197N SN74198N SN74199N SN74221N SN74251N SN74273N SN74279N SN74283N SN74284N SN74285N SN74290N SN74298N SN74365N SN 74366 N SN74367N SN74368N SN74390N SN74393N SN74490N 2.95 2.95 2.95 .62 1.95 1.20 1.09 .67 1.19 .78 .78 .87 1.20 1.95 1.69 4.75 1.75 .75 2.25 2.25 9.95 3.90 1.39 1.39 1.19 .95 1.05 3.90 3.90 1.25 CMOS CD4000 CD4001 CD4002 CD4006 CD4007 CD4008 CD4009 CD4010 CD4011 CD4012 CD4013 CD4014 CD4015 CD4016 CD4017 CD4018 CD4019 CD4020 CD4021 CD4022 CD4023 CD4024 CD4025 CD4027 CD4028 CD4029 CD4030 CD4031 CD4032 CD4034 CD4035 CD4037 CD4040 CD4041 CD4042 CD4043 CD4044 CD4046 CD4047 CD4048 CD4049 CD4050 CD4051 CD4052 CO4053 CD4055 CD4056 CD4059 CD4060 CD4066 CD4069 CD4070 CD4071 CD4072 CD4073 CD4075 CD4076 CD4077 CD4078 CD4081 CD4082 CD4085 .CD40S9 CU4093 CD4094 1.39 1.15 .59 1.19 1.10 1.19 1.15 3.25 2.15 3.25 .95 1.95 1.29 1.25 1.10 1.10 1.10 3.95 2.95 9.25 1.39 1.95 2.95 CD4098 CD4099 MC14408 MCI 4409 MC144t0 MC14412 MC14415 MC14419 CD4501 CD4502 CD4503 CO4505 CD4506 CD4507 CD4508 CD4510 CD4511 CD4512 CD4515 CD4516 CD4518 CD4520 CD4555 CD4556 CD4566 74C0O 74C02 74C04 74C08 74C10 74C14 74C20 74C30 74C32 74C42 74C48 74C73 74C74 74C85 74C89 74C90 74C93 74C95 74C107 74C151 74C154 74C157 74C160 74C161 74C163 74C164 74C173 74C174 74C175 74C192 74C193 74C195 74C240 74C244 74C373 74C374 74 C922 74C923 MM80C95 MMH0C97 2.29 2.25 12.95 12.95 12.95 12.95 8.95* 4.95 .39 1.65 1.19 1.39 2.75 .99 1.35 1.79 5.95 1.19 1.19 1.49 1.19 2.49 3.50 2.10 1.65 1.55 1.65 1.55 1.35 1.35 2.19 2.19 2.39 2.39 5.39 5.65 1.50 1.25 74LS00N 74LS01N 74LS02N 74LS03N 74LS04N 74LS05N 74LS08N 74LS09N 74LS10N 74LS11N 74LS12N 74LS13N 74LS14N 74LS15N 74LS20N 74LS21N 74LS22N 74LS26N 74LS27N 74LS28N 74LS30N 74LS32N 74LS33N 74LS37N 74LS38N 74LS40N 74LS42N 74LS47N 74LS48N 74LS51N 74LS54N 74LS55N 74|_S73N 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 74LS158N 74LS160N 74LS161N 74LS162N 74LS163N 1.05 74LS164N 74LS165N 74LS166N 74LS168N 74LS169N 74LS170N 74LS173N 74LS174N 74LS175N 74LS181N 74LS190N 74LS191N 74LS192N 74LS193N 74LS194N 74LS195N 74LS196N 74LS197N 74LS221N 74LS240N 74LS241N 74LS242N 74LS243N 74LS244N 74LS245N 74LS247N 74LS248N 74LS249N 74LS251N 74LS253N 74LS257N 74LS258N 74LS259N 74LS260N 74LS261N 74LS266N 74LS273N 74LS275N 74LS279N 74LS283N 74LS290N 74LS293N 74LS295N 74LS298N 74LS324N 74LS347N 74LS348N 74LS352N 74LS353N 74LS363N 74LS365N 74LS366N 74LS367N 74LS36SN 74LS373N 74LS374N 74LS375N 74LS377N 74LS385N 74LS386N 74LS390N 74LS393N 74LS395N 74LS399N 74LS424N 74LS668N 74LS670N 81LS95N 81LS96N 1.69 81LS97N 1.69 81LS98N 1.69 1.15 1.15 2.20 1.15 . 1.15 .95 1.15 1.69 1.69 1.69 1.69 1.49 2.20 1.10 1.75 4.40 1.9S 1.19 1.89 1.89 1.70 2.35 2.95 1.75 2.29 LINEAR 5.95 1.49 .99 2.95 78H05 78M06 78M.G. LM105H LM108AH LM300H .79 LM301CN/H .35 LM304H .98 LM305H .89 LM306H 3.25 LM307CN/H .29 LM308CN/H .98 LM309K 1.49 LM310CN 1.25 LM311DOI/H .89 LM312H 1.75 LM317T 1.70 LM318CN/H 1.49 LM319N/H 1.25 LM320K-XX' 1.35 LM320T-XX* 1.39 LM320H-XX' 1.25 LM323K 4.95 LM324N LM337K LM338K LM339N LM340K-XX* 1.75 LM340T-XX* 1.25 LM340H-XX' 1.25 LM344H 1.95 LM348N 1.20 LM350K 5.60 LM358CN .98 LM360N LM372N LM376N LM377N LM380CN/N 1.25 5.95 6.95 1.49 LM381N LM383T LM386N LM387N LM390N NE531V/T NE555V NE556N NE561T 1.79 19.95 NE565N/H 1.25 1.75 1.50 2.75 .99 .29 .75 .39 1.95 NE566HW NE567WH NE592N LM702H LM709N/H LM710N/H LM711N/H LM715N LM723N/K LM733N/H .98 LM739N 1.15 LM741CN/H .33 LM741CN-14 .19 LM747N/H .75 LM748N/H .39 LM760CN 2.95 LM1310N 1.90 MC1330 195 MC1350 1.95 MC1358 1.75 LM1414N 1.90 LM1458CN/N .49 MC1488N MC1489N LM1496N LM1556N LM1820N LM1850N LM1889N LM2111N LM2900N LM2901N LM2917N CA3013T CA3018T CA3021T CA3023T CA3035T CA3039T CA3046N LM3053N CA3059N CA3060N CA3062N LM3065N CA3080T CA3081 N CA3082N CA3083N CA3086N CA3089N CA3096N CA3097N CA3130T CA3140T CA3146N CA3160T CA3190N CA3410N MC3423N MC3460N SG3524N CA3600N LM3900N LM3905N LM3909N LM3914N LM3915N LM3916N RC4131N RC4136N RC4151N F1C4194TK RC4195TK ULN2001 ULN2003 SN75450N SN75451N SN75452N SN75453N SN75454N SN75491N SN75492N SN75493N SN75494N TL494CN TL496CP .99 .89 1.50 2.50 2.95 2.19 1.99 3.49 2.99 2.75 1.29 1.29 1.49 3.19 3.19 4.95 1.49 1.29 1.55 3.49 1.99 1.30 1,19 2.49 1.19 1.95 3.95 3.95 3.39 .89 4.20 ADVANCED COMPUTER PRODUCTS 3 7225 Graphics Plotter 1795 00 3 16K Memory Module 265 00 1 5 1/4 1 ' Dual Master Fie* Disk Drive. 210000 3 5 1/4" Single Masler Flex Disc Dnve1295 00 3 Personality Module 700 00 » ROM Drawer 40 00 1 Plotter/Printer ROM 130 00 D Input/Output ROM 260 00 3 Matrix ROM 130 00 3 Serial Inlerlace (RS-232C) HP-83 $1895. Hp-.11: Powerful, Yel Eaty to Use • TheHP-41 communicates with HP 41-CV you in words as well as numbers ■ • You can customize Ihe HP-41 lo your own design • Programming is last and easy • Continuous Memory saves everything • Optional Peripherals allow you to expand capabilities HP-41 System I 398 00 u ..,.„ HP-41 System II 675 00 HP-41CV HP-Card Reader 178.00 275.00 HP-Optical Wand 105 00 HP-41 C HP- Plolter'Pr inter 315.00 19B.0Q HP-OuarJ RAM 85 00 icippkz computer v Sales and Service Apple II® 64K • Z-80Softcard Maxi-SvstPm • 16K Ram Card mdAI Oy&lBIII • Disk II w/controller • Apple II w/48K Call for more pricing! Total Value $2719 00 your price $2229 00 save'- For Pascal System add $425'"' mmpppki H hardware clearance up to 25% off 559 95 45995 42595 159 95 189 00 159 95 169 95 49.95 29 95 3699 00 „ MINIMOVER-5 j^cr 6 "^ 1 ROBOTIC ARM Completely ^^m^^L nation or ^m Assembly ^^H ^B ^B lIC PnciDlfiS .A ■ Automation or Robolic Assembly j • Education In f Robotic Priciples • Artillcial Inteligence Experiments • Computer Art and Games $1695 00 Armbasic Software lor TRS-8 w'Applications Manual Apphcations^RalcrencH Manu $39" $16" California Computer Systems 2200 SUPER S-100 BUY! • 12 Slot Mainframe • 64 Dynamic RAM • CP/M™ 2.2 • Z-60CPU 4 MHz w/Serlal 10 • Double Density Disk Controller • Interface to Vista V-1000 Chassis SPECIAL PACKAGE PRICE FOR COMPLETE SYSTEM with (2) Shugart Double Density Floppys mounted. add 1495. °° 1899.°° Proto Clips 14-P.nClip PC-) 4 16-PmCltp PC-16 . LM-Pin Clip PC-24 .10-Pin Clm PC-40 Proto Boards 1695 PB-104. .. 54.00 1B0O PB-203 . 97 00 2100 PB-203A 14900 25 00 PB-203A-Ki1 129 00 43 00 LV«W--U!»!ife AUTO-CAT Automatic Answer Direct Connect 0-300 Band List 279 95 ACP 245 95 PAT™ List 198 °° Answer Originate ACP 1 69° D-CAT™ direct Connect \ 0-300 Band. List 249"- ACP189 00 Rockwell Sin 9 le Board Computers AIM65w/1K 435.00 AIM65w/4K 475.00 8K BASIC ROM 99.00 . 4K ASSEMBLER ROM 84.00 ■ POWER SUPPLY 64.95 ENCLOSURE 49,95 TOTAL SYSTEM w/4K 669.00 SYNERTEKSYM-1 239.00 SD Z-B0 STARTER KIT 367.00 SD Z-80 STARTER KIT AST 450.00 SD SBC 100 Z-80 A&T 367.00 SD SBC 200 Z-80 A&T 399.00 RCACOSMACVIP 199.00 CROMEMCO Z-80 SBC 449.00 OalssBvar'-UninmrruplaOle PS CCS Pirill.1 Card TT Vac«lyiBi'"Voii;eCari] . .. Vis>on B0'-80»J4 Card Apple MiSpeaflSer Vision 4O'"40 col onhancnmoni A 600 Quad Dnni5ly6' Conlrolloi 595 00 MicroaollZBOSollcard . . Apple Grjph.es Tab SSU AlOSerialJParaliellO Apple Prototype Cai CCS Asynchronous 7710 A Sanal Apple Joyslick "GESU" pppte/ff T P r j^ New #appta software Visicalc— Now Belter Than Ever 169.00 Visiplot— Graph your Visicalc Worksheets 149.00 Visitrend/Visiplot— Visiplot w/Trend Analysis 239.00 Visidex— The Ultimate DBMS Visicalc Compatible 219.00 Visi term— Communicate w/olher Systems 209.00 BPI General Ledger 299.00 BPI Accounts Receivable 299.00 BPI Inventory 299.00 Stockfile Inventory System 349.00 Infotory Inventory System 289.00 Microcom Microcourter 229.00 Microcom Microlelegraph 229.00 Accounting Plus II Biz Pkg. 1250.00 Stoneware DB Master 189.00 Stoneware Utility Pkg (For above) 89.00 ACS BASIC ACCOUNT accounting syslem inc Buy System and Save We only offer Apple CPM software which has been evaluated by our software stalf WORDSTARThe Benchmark of Wordprocessing software requires Z-B0 & 80x24 349.00 VTS-80 CP/M-Wordprocessor has no screen menus uses new keycaps (supplied) to display Key functions 319.00 New MAILMERGE-A Wordslar Enhance- ment Pkg. allows lorm-letter genera- tion & chained printing 169.00 SPELLGUARD-Wilt proofread Wordstar & VTS-80 Text files against an expandable 20,000 word dictionary 169.00 SUPER SORT-Will sort, merge. & perlorm record selection on your CP/M Data Files 169.00 FORTRA 80-By Microsoft 195.00 COBOL 80 By Microsoft 749.00 NG SYSTEM, Total udes G/L, A/R, A/P. 699.00 New Breakthru in Apple II* Mass Storage! Vista A800 Quad Density DMA 8" Disk Controller i * S.8BB ly$595° I Special Complete Subsystem Offer • V1000 w/two Qume Datatrack 8 • Cable, ready to run • A800 Apple II 8" Disk Controller Total Value $2939 00 your price$2495 00 AATARI 800 & 400 r-\ Personal Computer System ATARI 800 $799°° ATARI 400 $375 00 ATARI 80O Includes: Computer Console, BASIC Lang. Cartridge, BASIC Language Programming Manual. 800 Operator's Manual w/Notebook, 1 6K RAM Module, Power Supply. TV Switch Box. BiOuisc Drive Program Recorder Silftn - HDD C.mlrj,.. EaucawyiSysitm Masler C Atari BASIC Assemble r Deoug Baskets ■■ Ctynjujie' Cness .499.00 Home f, ranee 295 00 [taulrM 1,11m Cruuni rnfrwi 795.00 uS h.sw> J9 95 US Govtrnmrjnl 5-1 % SustrwsiVV Sfcii'i 189.95 weuiUxi* Bull to mKtanMyind etetncaiy accomodate tnf sried 4«w- reJutria, f* "wl P**** 8- rtfl MnfUMI iW Sricart top* 4» aim art B- ndi WMmmg lapn hys • Strap opacity trumO) lo40magatycs * irdusfl^ o*«y catxrW a-£ TECH 300 Digital Multimeter S110 ™ TECH 310 Digital Multimeter * S TECH 330 Digiial Multimeter $189 VC-201 Vinyl Carrying Case S10 DC-202 Deluxe Carrying Case S24 HV-211 High Voltage Probe $35 RP-221 RP Probe $35 Ct-231 AC Current Clamp 5W2 DL-241 DelxueTest Lead Kit S10 TL-242 Square Test Leads So INTERSYSTEMS The Preferred S-100 Box The new Series II CPU Board features a 4 MHz Z-80A CPU and lull-feature front panel. 20-slot actively terminated mother- board, with 25 amp power supply (50/60 Hz operation, incl. 68 cfm fan). DPS-1, List $1795 ACP Price $1499 SYSTEM 2A with Z-80A CPU 4 MHz, 64K RAM, I/O Board, 20 slots, front panel, double density disk controller board. Full 1-year warranty. List $3795 ACP Price $2995 16 Slot Mother Board Card Cage 8 Slol Mother Board Power Supply DC Input Power Supply Utility Prolo Board Antn Proc/Memory Module 96 1 2 Buttered Utility Proto Board 9616 32K EPP.OM/P.AM Module 9617 EPROM Programming Head 9620 16 Channel Parallel t/O Module 9622 Senai-Parailei I/O Module 9627 16K Static RAM Module 470ns 9629 32K Static RAM 450ns 9629A 32K Static RAM 200n S 9630 Card Extender 9640 Multiple Programmable Timer 9650 S Channel Duplex Serai I/O Mod 9665 intelligent Tape Controller 96103 32/32 I/O Module 96702 Contact Closure Module UNPOPULATED BOARDS (Also Available) MICROPROCESSORS ZOOOi i6bi!toBMb $18900 Z8002 16 bi! IOG4K . 14900 Z80 9.95 280A 13.95 F-8 (38501 1695 2650 16.95 CD 1802 9.75 8080A 4.75 8080A4MH1 1995 SALE 8085 14.95 8008-1 14 95 2901 9 90 2901A 1495 2903 4-o.t Supe'siice 29 95 TMS99O0JL 49.95 CP'GOO 39.95 6502 995 6502A 1695 IM6I00 29.95 6SOO 11.75 680OB20MHI 1995 6802P 1795 6035 14.9 5 8039 19.95 INS6073N 24.95 8755 49 95 8748 6995 6809 37.95 8086 69.95 ADVANCED SUPPORT AM95H Anth, Processor . 175.00 9512 Anim Processor. 175 00 9513 Un,v Timing 79.95 AM95' 7 DMA Controller 18.95 AM95 ' 9 Universal Iniemjpl 18 95 Z-80 SUPPORT CHIPS Z80-PIO 2 5 MHz 3.75 Z80A-PIO 40 MHz 12.95 Z80-CTC 2.5 MHj B.75 ZSOA-CTC 4 MHz 12.95 ZBO-DMA 2.5 MHz . 29.95 Z80A-DMA 4 MHz . .36.95 Z80-5IO.'0 2.5 MHz 35.95 Z80A-SIO/0 4.0 MHZ 39.40 Z80-SIO/1 2.5 MHz 35.95 Z80A-SIO/1 4.0 MHi ,39.40 ZBO-SIO/2 25MHz 35.95 Z80-SIO/2 4 MHz 39.40 8080/8088 SUPPORT 8155/8156 1/0 24.95 6755 I/O wiin Eprom 64.98 B202 Dyn Rem Com... 34.96 8205/74S 138 Docodar 3 95 82i260.li/o 275 82 14 Priority Int. 5.25 8218 Bus Driver 2.75 622-1 Clock Go.-. 2.95 8224-4(4MHz) 9.78 8226 Bus Dnvsr 2.96 ST2G BusO/iver 2.95 8228 Sys ContfOI 4.50 823BSyS Conl 6.50 8243 HO Exp 9.50 8250Asyn.Comm 15.98 8251 Prog I/O 8.95 8253 Int Timer 12.95 8255 Prog. I/O 6.50 8257 Prog DMA ... . 16.95. 8259 Prog, irtl 15.95 8275 CRT Controller. . 45.95 8279 Prog Keyboard. 15 95 8800 SUPPORT CHIPS 6810 128- 6 Ram 4 75 5820 .6.50 6621 -6.50 6828 Priority Irtl 10.75 6834-1 512 « 8 Eprom ... .16.95 6845(HD46505CRTCont. .29.95 6847 Color CRT 29.95 6850 ACIA 5.95 6852 Serial /■.:.,.■>:.- 5.95 6860 Modem 10 95 6662 Modulator . 11.95 6671A 1 OMHtOSC . 25.96 6875 8.95 6880 Bus Or-ver . ... 2.19 MC6848B 19.95 88047 24.95 6502 SUPPORT CHIPS 6520 PIA 7.50 6522 Mult 11.96 6530-002 003.004.005.. . .21.95 6532 19.95 6551 . 19.95 BIPOLAR PROMS We do Custom Programming B2S23S330A6O0r74S18S 4.25 82S1l5(5l2x8)TS 12.95 82Sl23.'5810/74S2aB<32x8)TS. .4.25 82S126/5803r74S3B7<258".4)OC 4.25 82Si29.'5623/74S287(256x4)TS . 4,25 82Si3Gv5604/74S570(512x4)OC 650 82S131/74S571 {S12x4)TS 6.95 82S137/74S573 [1024x4)TS . . . 12.95 82S141I3824/74S474 |512x8)TS 12.95 82S147/74S472(512x8)TS .... 12.95 74S471/6309(256x8)TS 7.95 MOS PROMS 27&4(8KxB)TS 69.95 2732(4KxB|TS 16.95 2716f2516.5V(2KxB)TS , - TMS2716.i5V. 12V 17.95 2758.5V, fdMNU 7.50 2708 (45DNSI . 5.75 2706 i650Nb> .5.25 1702A MM5203AQ .14.50 CHARACTER GEN. 2513-001 15V) Upper 9 50 10 95 2513-AOM3(5V1 Lower ... 14 95 MCM66710 Ascli Shifted 12.95 MCM6674Q Math Symbol MCM66750 Alpha Conlrol 13,45 UARTS/BAUD RATE TRi602Bi5V 12V) 3 95 AV51013I5V irvi 4 95 AY51014A,A61?l514Vi 6 95 AVSI015A/1863I5VI 6 95 IM6402 IM6403 895 2360 USR1 9 95 I671B Asiros 24 95 ...9.93 STATIC RAMS 2IL02 4S0nf. /efc\-£ 2IL02 250ns (^ A i DP IC SPECIAL PURCHASE K2S09 64x9 Ram OP8304 Octal Oriver DAC66EXD/AConv. MC1650 Hi Speed A/D MC6852SSDA MC10145 16x4 ECL Ram MK3850fF8CPU MK3853Stat .46 78MQ6 .89 79M06 79 74157 .29 74161 .29 74C74 an SlopWaich SN75136 MC10210 LM339 LM710CN LM711CN ICM 7045Preci; ICM 7207 Oscill; . _ Seven Decade Counler 7208 MC 1 4433P 3' j 0>g<1 A/D Convener ICL 821 1 Voltage Reference LM 1850N Ground Faull IC LM 2900N Quad AmpMier LM 29 1 7 N Freg lo Volt Conv AV-3-3ii50 4'. digit DMM AY- 5-3 507 40MHi DVM MEM 4963 Mosiet Smoke Deiector 27S08 32 x 8 Prom (IM 5600) LLN 2003A 7 channel Driver . . MCM 14505 64 bit Static Ram MOC 1003 (4N2B)OptO Coupler SPX3.1 Opto Coupler IH 5045 CMOS Swilch DBST UA 3045 Trans Array TR 1402AUART MK 1007 Dyn. Mem Shirt Reg.. 5316TVCh Disp Circuit 6380A 8 Bit CPU 8700 CJ 8 Bil A/D MM5280/VPD41WC2 107/7MS 4060/ 4Kxl Dynamic 22 Pin RAM 6604/VPD 4 1 4/402 7/2660/MK 4096/ 4Kx1 Dynamic 16P.n 7520/25 1488/1489 (M323K 1 95 3/100 2/1 OC 2/1 99 24 95 9 95 795 2 95 69S 3/100 3/1.00 ,4.50 C1372 1M5298-4A B . M 377 M380 9 95 2 95 1 25 1 25 LM 387 LM 4558 HC4136 RC4131 COM 502/ COM 5037 TYPE VERBATIM DISKETTES 100% CERTIFIED ERROR-FREE! 3S riltCKS DOUBLE DENSITY SIKf.LE-SiOEO V. PRICE BOX $2995 J29 95 S2995 WD1941 995 COM 5016 16.95 INS 8250 15.95 KEYBOARD ENCODERS AVS-2376 --- 1375 AY5-3600 - - 13 75 I US Ah*; etc 525-16 <6 Mac Ham Metopous a 10 I U TMCR ODUIIE 0ENSIT1 - SINGLE SIDtD y, W'riUI HEINrOICEHENl DING 5'7D1 SOU Setlo'M tRS 80 dr. S32?S 57/-K- lOnmcHjiaNS Aou* el: 32 25 ■577-lf iBHnlc Ham Uctcws 3225 a 40 MACKS OOOILE SIDED OOUIIE OINSITT 5'. 550-0' SCI SeclrjrerJ SA J50 MPt 52 J3995 550-10 10HoleH*d BAS' WANGCD J39.95 55016 l&HMEHarfl MciO* 13995 a I ion*.. CENllflED DISKETTES FOfflXMJI Soil Single Density 3740 S3350 F0800-.1? 3? Harfl Smqie Oi'nsity Slmg 33 50 FD802-UI Sol! OaiDie Oensny 3740 MIB 'DB50'Ot Soil Dwo«rSG08 Ingh litors by appointmen S-100 MAINFRAME Mainframe includes 117/230 volt power supply and your choice of a six or twelve slot motherboard. Six slot enclosure is supplied with mounting provisions for one 5 1j floppy disk or Winchester drive. AC receptacle is provided for terminal or other ;ieeossory. Chass has been punched to accept six assorted computer connectors. Shipping weight 37 lbs. ENM-CD1 S265.00 =3. Shugart Associates 801/ R Disk Drive 15 lbs Shu sari 801/H with CP206 power supply, muf: plete in dual enclosure with all the H«BMIrJ Document at Urn Included. 36 pounds. MSD- 18 Same as above but with two Shugart 801R disk drives. 50 pounds. MSD-2B01 Disk drive cable. 6 reel 50 conductor with edge card c< at both ends. WCA-650S $25.00 Exporl Disk drives. 220V, 50MHz add $50,00 per disk haust fan, wm- !9 slng cable* */95 ♦1195 SHUGART 801R $ Qume Double SiHed B 1i«l< Drive '575 ■W' NEW from Shugart Technology m 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 IDC voltage. Dual California Digital 5 1/4" enclosure. fc* C AA STI30G drive and power supply. f *9vll Shugart Associates SA400 removable media disk drive for above package, add: S-100 & Apple controller scheduled for spring release. »300 DATA INPUT TERMINAL ind flbci-Kliiaa i-ncloiurc t keyhuaril. Thirty dinplay l.ur.p» ur Inch Unil npej.krr jchm,»U-Ji;ts endlnK problems, with a Utile Imagination, BM he MgEnMf □ S-100 computer imrf tUtO dlsplav o Rockwell Al-M-GS intcro/compulcr. liable for I condilion. Original acquisition over J700. 22 lbn. Regulated Power Supply 5 VOLT 5 AMP $U?5 ■■..-I- supplv Circle 51 on inquiry card. TOLL FREE ORDER LINE 800)421-5041 TECHNICAL & CALIFORNIA 213679-9001 TWX 910 325-6212 CaHFornia DiqiTAl Post Office Box 3097 B • Torrance. California 90503 I Enclosure for Two 8' ' Disk Drives and 12 Slot Motherboard $ . designed for c e fleet i\ Modular in concept. system integration. Buy as much as vou require. The basic enclosure is engineered from welded W structural steel, RF line filter insures thai the enclosure conforms to the Federal Communication Commis- sion RFI requirements. Two exhaust Tans provide maximun airflow across print- ed circuit cards. The enclosure has mounting provisions for two 8" Qume for Shugart disk drives .ind a 10 megabyte Winchester drive. The basic package is supplied with two AC accessory receptacles and all AC and DC power cables. Rear panel has been machined to accept nine assorted computer connectors. Shippinc weight 30 lbs. ENM-2D $375.00 supports two 0" disk drives and 12 slot motherboard. POWi:R SUPPLY nioun Shipping watght IS lbs. MOnil-JUBOAHD with noise canceling basket-weave ground plnnu. Complete with twelve gold S-100 edge connectors and curd cage. Shipping weight 3 lbs. BDB-MTIU2C JD9.00 World's Beat Selling Printer EPSO MX 80 Immediate Delivery Only $ 475 Paper Tiger 560G s 1350 rYECSpinwriter 551DP/S I'ti- word proccsmnR (polity Spinwrit.?r prims at speeds upio iclcri pet second. Ph« Model ."."iifii'/s is supplied witli boil. [<««•«< ind us-:::':: aortal Interfticinj. Uso included is ilte tracior feud much inlitu, alonj; Willi print tlitnMlle ,.id riyi.on. PRN-5ol0FS 71) U.S. ^•vhoartUKSH) M.,rl.-1 o20l'/S available S2U05. PRN-iiWe PS 7 fi His. PRINTRONIX P-300 $ 4500 P-600 *6150 PRINTERS Epsoi Epaoi An ad Anadi An act IDS F IDS '1 MX80 PREMX80 MX80FT PBEMXS0F NLX100 PREMX100 x D500 PSA9500 x 9501 PRAS501 m ISO PRA150 PBO480G PRG560G PRD63G PRU1G50 PRD 10-10 PRD180 PBP300 PRPGOO ■ Tgr. j u:io i 1BS0 3 lfi-10 NEC/Sellum 1 PRHSSlOpa 2fi'J5 NEC/Sin 1GK PRN55IGps 2795 TEC/Slarwril. PRV300 1395 Okidata 80 probo 419 Okidata 82 PROB2 819 Okidata S3 PROfKt 895 Teletype 4UK PTT4320K 1095 Texas Ins. MO PRT810B 1450 Tex. Ins 810C PRT810C 1795 Centronics 730 PRC730P 529 Centronics 737 PRC737P 695 Centronics 739 PRC739P 795 Centrnx 704-9 PRC70-1-9 1495 Cenirnx.704-11 PRC704-11 15G9 SYSTEMS A m\?M 48K MEMORY 1170 2650 WKp% HEWLETT Wf/iM PACKARD HP85 ll...w/P.ick 85 SYSIIPS5 2650 Hew/Pack 03 SYSHP83 1895 Altos AC58000 SV5ACS8000 4795 Osborne 1 SYSOBI 1795 Commodore SYSC8032 1495 Commodore SYSC8096 1795 3upt»rbraia84QSYSSB64Q $3350 Superbrain64USYS.SB64D 2850 Northstard4Q SYSNG4Q 3295 Northstar G4D SYSNG4D 2895 NEC/PCBOOO SYSPC8000 call Apple II Plus SYSAP 1170 VISA === = 3101 : ==== Display ' =T= Terminal IBM Direct Price '129. California Digital $ 1195 discount price AMPEX DIALOGUE 80 CRT TERMINAL J 995 : Ampex Corporation. The DUlojUO III) natural removable keyboard ihle two pages (four optional! du;tl program keys, half intensity protected ileitis and status line. Transmits rlat.i either block, line or character mode. Excellent value. VDT-DB0 shipping 47 lbs. VIDEO TERMINALS ADDS Regent 25 numeric cluster VDT-R25 $850 ADDS Regent 30 25th status line VDT-R30 950 ADDS Regent 40 limited graphics VDT-R40 1195 ADDS Regent 60 Block mode VDT-R60 1495 Ampex Dialouge 80 two page.detatch VDT-D80 995 Digital Equipment VT-100 VDT-V100 1595 Digital Equipment VT-132 VDT-V132 1895 Direct VP-800A emulator VDT-P800 call Hazeltine 1410 VDT- Hazeltine 1420 VDT- Hazeltine 1500 VDT- Hazeltine 1510 VDT- Hazeltine 1520 VDT- Hewlett Packard 2621A VDT- Hewlett Packard 2621P VDT- IBM 3101-10 character mode green VDT- IB.M 3101-20 block mode VDT- Lear Seigler 3A upper case only VDT- Lear Seigler AD.M5 VDT-L5 945 Lear Seigler ADIU31 VDT-L31 1385 Lear Seigler ADM42 VDT-L42 1995 Soroc IQ 120 VDT-Q120 675 Soroc IQ 135 NEW VDT-Q135 850 Soroc IQ 140 detatchable keyboard VDT-Q140 1150 Televideo 912C VDT-T912 665 Televideo 920C VDT-T920 745 Televideo 950C detatchable keybd. VDT-T950 985 Zenith Z-19 VDT-Z-19 735 H1410 750 H1420 795 HI 500 850 H1510 1025 H1520 1225 HP21A HP21P 3101 1195 31012 1395 L3A 850 VIDEO MONITORS BMC ECQ12C 18MHz P-31 grn phosphor $259 Leedex/Arndek 12"100 129 Leedex 100 green 169 Leedex 100-80 197 Hitachi color 13" 389 Zenith color 13" 379 NEC green phosphor 219 Panasonic color 10" Sanyo 9" BW 149 Sanyo 12" green phos. 235 Sanyo 15" BW 259 Sanyo 13" color 419 Shipping: First five pounds $2.00; each additional add $,4t orders 10% shipping. Excess will be refunded. iiu residents add 6% sales tax. COIJ's discourage tended to state supported educational ins mmmm. Wa (itors by appointment. Correspondence quality printing. A lot ol printers costing a lot more can't touch the MX-fSTs performance. It gives you a choice of 40, 81). 66 or 132 col- umns of printing in js many as four distinct printing density modes, a total of twelve different combinations which can accommodate nearly any printing requirement. Bidirectional printing. Logical seeking I of shortest linos. HO CPS. 64 graphics characters. Forms handling. The list of standard features goes on and on. The file I is thai there are few printers that can compete with the MX-80.il ANY price. And none— ZERO — in its extraordi- narily affordable price range. ABCDEFGHIJKLI1NDPDRSTUVWXYZABCDEFGH1J Ti I iT.v.Wh* .". :WW? n fWrH I ACCESSORIES FOR THE COMPUTER CALIFORNIA COMPUTER SYSTEMS Arithmetic Procea.ior 781 1 B/C $319 Asynchronous aerial Interface 7710 123 Centronics Interface card 7728 B5 12K PROM Module 7114 6B Calender/ CI ock, Hal. back-up 7424 99 Parallel Interface 7720A 98 Procramable Timer 7740A 99 Analog/Digital converter 7470A 09 MICROSOFT PRODUCTS Apple to Z-80 CPU card 373 D.C. HAYES PRODUCTS Micromodem for Apple 31S COMPUTER STOP PRODUCTS Double Vision /B0 Column Video 25C INTERACTIVE STRUCTURES 16 Channel A/DcardAlO/2 275 MOUNTAIN COMPUTER PRODI' C Intro X-10 system for BSR { Intro X-10 card onlv 16 channel AD/DA 8 bit Apple Clock hatterv back-up Supertalker SD200 ROM Plus with filter ROM Writer/ Programmer 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 B" floppy controller (Pascal) S-100 BOARDS Assembled • Tested • Burned-in CPU BOARDS Calif. Computer 2 J10A /.-no dma. vm* lilJC c:;iiio s: UdJIioui Z-80 24 t l, 4.\illz BUG GZ ao L Godtxxtt uoii.yijoHii dual 1 BDC (J88 : Measurement Syst emu Z -no 4 eerial 2 parallel r al Ultra clock, H vector BDC MX HO L SI) Svsu-n>s sue-: JO 7. HO with serial 4 p Mill.' I/O pons BDC SBC2 Teletelt l-UC-I a nste CPU A Floppy disk ct it roller plus I/O BDC FDCl G MAINFRAMES Cal«. Computur 2 200A 12 slot K ENM -C2200 ; TEI 12 yli.t l.ilil.: ENAI -T12 TBI 22 slot table ENM -T22 1 Godbout ni.iiufrii'. ENM -UM1- UEft ORY HOARDS Calif. dya. Clif. mputer 206.'iA G IK i n tmorv BDM-CSOSif mpUtBT 2010 18K men.orv HDM-C201IS mputer 2032 32K memory BUM-C3032 law 17 S4K static ■v IS bit uiiM-an 1- LOPPY DISK CONTROLLER Calif. Computer 2422A with 2.2 CP.M BDF-C2422 (jodbout "Disk (Ate" features th NEC 765 controller. DMA arbitration BDl -GDI Meas I Syst 765 recovery BD1--MF SD Svstems Veraafloppy II douhle densitv BDl- -VI- '.'. Turbell IJ/D BOF-TF! Morrow Deaigri Disk Jockey 1 sififile density HDl'-DJl ■ ai.lv.- >!..-. sum i < Jocke' BDl'-DJa II INTERFACE BOARDS Calif. Con^puter 2718 I/O 2 serial/2 par 1 BDT-C2TIH Morrow Designs Switchboard 2 serial/4 pari BUT- MSB Morruw Designs Uultiboard J B*triaI/3P. — - BDT-MMB liodhoul Enterf.tcer Che 2 serial/2 pari UD5-Gtl Godboul Interfacer Two 1 serial/3par! BDS-CB3 SPECIALlnf BOARDS CJT Computet ilock/ BUS-QCK wrap proio- BDS-AWW rtL-c Elec. Ceneral Purpose proto board BDS-AOP odhout Spectrum color board BDS-USC . C. Hayes S-1CIU Micro- modem HDS-H.\I1 lulleo Products extender boan *. lopic prolji- kt HDS-Ml'ltl Art HDS- .H ■ Rotron Muffin Fan | *1 4 77 $12.00 fe 100 10.50 6 1000 115 VAC. 7 Watts WR2A1 Factory fresh Muffin fans NOT pull-outs. EMF-4M Circle 51 on inquiry card. TOLL FREE ORDER LINE 800)421-5041 TECHNICAL & CALIFORNIA (213)679-9001 TWX 910325-62121 7400 SN74O0N 5N7401N SN7402N SN7403N SN7404N SN7405N SN7406N SN7407N SN740BN SN7409N SN7410N SN7411N SN7412N SN7413N SN7414N SN7416N SN7417N SN7420N SN7421N 5N7422N SN7423N SN7425N SN7426N SN7427N SN742BN SN7430N 5N7432N SN7437N SN7438N SN7439N SN7440N SN7441N SN7442N SN7443N SN7444N SN744SN SN7446N SN7447N SN7448N SN7450N SN7451N SN7453N SN7454N SN7459A SN7460N SN7470N 74LS0O 74LS01 74LS02 74 L 503 74LS04 74LS05 74L.S06 74LS09 74LS10 74LS11 74LS12 74LS13 74LS14 74LS15 74LS20 74LS2I 74LS22 74L.S26 74LS27 74LS28 74LS30 74LS32 74LS33 74LS37 74LS38 74LS40 74LS42 74LS47 74LS48 74LS49 74LS5J 74LS54 74LS55 74LS73 74L574 74LS75 74LS76 74LS78 74LS83 74LSS5 74LS86 74LS90 74500 74502 74S03 74504 74 SOS 74S08 74 S09 74S10 74SU 74 SIS 74520 74S22 74S30 74532 74S38 74540 74S51 74S64 74S65 74S74 74S86 745 112 74SJI3 74S114 SN7472N SN7473N SN7474N SN747SN SN7476N SN7479N SN7480N SN7482N SN74B3N SN74B5N SN7466N SN7469N SN7490N SN7491N SN7492N SN7493N SN7494N SN7495N SN7496N SN7497N 5N741QQN SN74104N 5N74105N 5N74107N SN 74109 N SN74116N SN74121N SN74122N SN74123N SN7412SN SN74126N SN74132N SN74136N SN74141N SN74142N SN74143N SN74144N SN7414SN SN74147N SN74I48N SN74150N SN741S1N SIM74152N SN74153N SN74154N SN74155N 3.25 3.49 3.49 W$ SN74156N SN74157N SN74160N SN74161N SN74162N SN74163N SN74164N SN 74165 N SN74166N SN74167N 5N74170N SN74172N SN74173N SN74174N 5N74175N SN74176N 5N74177N SN74179N SN741S0N 5N741B1N SN74182N SN741S4N SN741SSN SN74190N SN 74191 N SN 74192 N SN74193N 5N74194N SN74195N SN74196N SN74197N SN74198N SN74199N 5 N 74221 N SN742S1N SN74276N SN74279N SN74283N SN74284N SN74285N SN74365N SN74366N SN74367N SN74368N SN74390N SN74393N 74LS 74LS92 74LS93 74LS95 74LS96 74LS107 74LS109 74LS112 74 LSI 13 74LS114 74LS122 74LSI23 74L512S 74LS126 74LS132 74LS133 74LS136 74LS138 74LS139 74LS151 74LS153 74LS154 74L5155 74LS1S6 74LS157 74LS1S8 74LS160 74LS161 74LS162 74LS163 74LS164 74LS16S 74LS168 74 LS169 74LS170 74LS173 74 LSI 74 74LS17S 74LS181 74LS190 74LS191 1.15 1.15 1.15 1.19 1.19 1.95 74LS192 74LS193 74LS194 74LS195 74LS197 74 L 5221 74LS240 74LS241 74LS242 74LS243 74LS244 74LS245 74LS247 74 LS248 74LS249 74LS251 74LS2S3 74LS2S7 74LS258 74LS260 74LS266 74LS273 74LS279 74LS283 74LS290 74 LS293 74LS298 74LS352 74LS353 74LS36S 74LS3G6 74 L 5367 74LS368 74L5373 74LS374 74LS37S 74LS386 74LS393 74LS399 74 L 5670 81 L 595 81LS97 74S 74 S 124 74 S 133 74 S 134 74S13S 74S136 74S138 74S139 74S140 74S151 74S153 74S157 745158 745160 745 174 7451 75 745188 74S194 745195 74S196 74S240 74S241 74S242 1.95 1.95 2.95 2.95 74S243 74S244 74S2S1 74S253 74S257 745258 745260 74S2B0 74S2B7 J4S2BB 74S373 74S374 74S387 74S47] 74S472 74S473 745474 74S47S 745570 74SS71 745572 74S573 74S940 74S941 1.15 1.15 1.15 1.15 1.19 1.19 2.49 2.49 2.49 2.75 3.49 3.49 2.95 19.95 10.95 10.95 12.95 12.95 5.95 5.95 9.95 9.95 4-Digit 16 Segment Alphanumeric Intelligent Display with Memory, Recorder, Driver End-siackoble, 4-choracier package. High con- trast, IGOinii high, magnified monolithic character*. W Chnnictor ASCII formal. Built-in memory, decoder, multiplexer and drivers. Direct access to each digit independently and asyn- chronously. Five volt logic, TTL compatible. Fiva volt power supply only. Independent cursor func- tion. Site: 1"L x 1-3H6-H x .225 'D. DL-1418 Alphanumeric Display $19.95 M, ZJ 10-Segment Bargraph Displays (with On-Board Driver IC-Chip) Size: 2"L X 7/8"H x 3/lG"D tsat or dot display mode externally selectable by user. Packages era end-stackablo for expended displays. Can be cascaded to 10 arrays 1100 bargraph elements!. LEO current programmable from 2mA lo 30mA. Stable internal voltage reference for full scale analog inputs from 1.2 to 12V. Each LED output of driver IC with external access. Size: 2"x7/8"x3/1S". NSM3914 Linear Function [10 barm red) *6.96 NSM39146 Linear Function [Bbara graen/4 red) 8.86 NSM3916 Logarithmic Function (10 bars red) 5.96 NSM3916B Logarithmic Func. (8 grn./2 yell./ 2 rd.l 8.86 NSM3918 VUMeter Function M0 ben red) 5.96 NSM391B8 VU-MeierFunc. (8grn./2 yelf./2rd.l 6.96 DISCRETE LEDS XC556R .200" red XC556G .200" green XC556Y .200" yellow 4/S1 XCS56C .200" clear XC22R .200" red XC22G .200" green XC22Y .200" yellov MV10FJ .170" red 4/ii 5/H 4/J1 4/J1 4/S1 MV50 .085" red XC209R .125" red XC209G .125" green XC209V .125" yellow XC526R .IBS" red XC526G .185" green XCS26Y .185" yellow XCS26C ,185" clear C.A. — Common Anode D.D. — Double Digit ■ ; 200(TI^)Rea7Gr c c i Diffused Bi-Calor LED Part No. 1-99 100+ ^, ^ MmL RL-2 . . $.39e-;i.or 3/S1.00 Type MAN 1 MAN 2 MAN 3 MAN 52 MAN 54 MAN 71 MAN 72 MAN 74 MAN B2 MAN 84 MAN 3520 MAN 3630 MAN 3640 MAN 4610 MAN 6610 MAN 6630 MAN 6640 MAN 6650 MAN 6660 MAN 6710 MAN 6740 MAN 6750 DLO304 DLO307 DLG500 Polarity C.A.— red 5x7 D.M.— red C.C.-red C. A.— green C.C.— green C.A.— red C.A.— red C.C.— red C. A.— yellow C.C.— yellow C.A.— orange C.A. —orange ± 1 C.C.— orange C. A.— orange C.A.— orange— DD . C.A. —orange ± 1 C.C.— orange— DD . C.C.— orange * 1 C.A. —orange C.A.— red— DD C.C.-red— DD C.C.-red ± 1 C.C.— orange C.A. —orange C.C.— green DISPLAY LEDS t Price '0 2.95 Type DLG507 DL704 DL707 DL728 DL741 DL747 DL7S0 DLOS47 DLO8S0 OL33S FND358 FND357 FND500 FND507 HOSP-3401 HOSP34Q3 C.C, HDSP-3406 C.C. red 5082-7751 C.C. - RHD Polarity C. A.— green C.C.-red C.A. -red C.C.-red C.A.— red C.A.— red C.C.-red C.A,— orange C.C— orange C.C.-red C.C. ± 1 C.C. C.C. (FND503) C.A. {FNDS10) C.A.— red ;ommon Cathode Right Hand Decimal Ht Price : 1 5082-7760 5082-7300 5082-7302 5082-7340 4N28 LtT-1 MOC3010 .430 C.A..R.H.D.— red C.C.R.H.D.— red .430 4x7 Numeric (RHD). 600 4x7 Numeric (LHD). 600 4x7Hxdcl.(Q-9/A-F) .600 Photo XslstorOpto-lsol. Photo Xsistor Opto-lsol. Optically Isol.TriacDrlvt 1.2S 1.25 22.00 22.00 22.50 SOCKETS ^^^■fc. RECEPTACLES Test if*^ Sockets ZERO INSERTION FORCE Part No. Pins Price 214-3339 14 pin 5.95 216-3340 16 pin 6.49 218-3341 18 pin 7.95 220-3342 20 pin 8.95 * Nickel Boron Plating * G.F.PSF Plastic Body * For testing IC'i PartNo. Pins Price 222-3343 22 pin 9.95 224-3344 24 pin 9.75 228-3345 28 pin 11.95 240-3346 40 pin 12.95 LOW PROFILE (TIN) SOCKETS 8 pin LP 14 pin LP !6 pin LP 18 pin LP 20 pin LP 22 pin LP 24 pin LP 28 pin LP 36 Pin LP 40 pin LP SOLDERTAIL 19 82 „^ tcAf&SS* lameco ELECTRONICS Spec Sheets - 254 Send 86ff Postage for your FREE 1982 JAMECO CATALOG PHONE ORDERS WELCOME (415)592 8097 MAIL ORDER ELECTRONICS - WORLDWIDE 1355 SHOREWAY ROAD, BELMONT, CA 94002 PRICES SUBJECT TO CHANGE .1/35V . 15/35 V . 22/35 V . 33/35 V .47/3SV .68/35 V 1.0/3SV Axial .47/50V 1.0/SOV 3.3/S0V 4. 7/25 V 10/25V 10/50V 22/2SV 22/50V 47/25V 47/SOV 100/25 V 100/50V 220/25 V 220/50V 470/25V 1000/16V 2200/ 16 V .39 M .29 1.5/3SV 34 .29 2.2/35V M .29 3.3/25V M .29 4.7/25V 34 .29 6.8/25V 34 .29 15/25V 34 JM .29 ELEC 22/6V rROLYT M* 3 500+ Radial 14 .10 -47/25V lfi .12 -47/50V If. .11 1.0/16V IK .11 1.0/25V 15 .11 1.0/50V 16 .12 4. 7/ 16 V Ih .12 4.7/25V ?0 .18 4. 7/50 V ?1 .19 10/ 16 V 2ft .23 10/25V 24 .22 10/50V V .34 47/SOV 14 .33 100/16V 4S .41 100/2SV 4 • Holds 4 ea. C cells • Plastic case • 9" leads $.49 ea 10/S4.25 EPROM Erasing Lamp • Erases 2708, 2716, 1702A, 5203Q, 5204Q, etc. • Erases up to 4 chips within 20 minutes. • Maintains constant exposure distance of one 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 hording tray for 4 chips. UVS-11EL Replacement Bulb $16.95 UVS-11E $79.95 JOYS ICKS ; y JS-5K 5K Linear Taper Pots $5.25 JS100K 100K Linear Taper Pots $4.95 JVC-40 40K (2) Video Controller in case . . . $4.95 6-Digit Clock Kit • Bright .300 hfc comm. i ode display • Uses MM5314 clock chir. • Switches for hours, mir and hold modes easily viewable to 7 lated walnut case •115 VAC operation • 12 or 24 hr. operation JE701 $19.95 JE215 Adjustable 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 provides the 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 nag. 1.2VDC to 15VDC. ■ • Power Output (each supply): 5VDC $ 500mA, 1 OVDC @ 750mA, 12VDC@ 500mA, and 15VDC@ 175mA. Two, 3-torminal adj. IC regulators ■ Heats i LED ■ ogule JE215 Adj. Dual Power Supply Kit (as shown) . . $24.95 (Pic JE20Q Reg. Power Supply K ■ in construction to above) . 5VDC, lamp) . . $14.95 JE205 Adapter 3rd. (to JE200) i 5, ■ 9 & ±12V. $12.95 JE210Var.Pwr. Sply. Kit, 5-15VDC,to1.5amp. $19.95 MICROPROCESSOR COMPONENTS 8080A/8080A SUPPORT DEVICES DP821! 8-Blt Input/Output DPB2H Priority Interrupt Control OPB216 BIDIretlloml Bui Drivar DP8224 Clock Ganeratoi/Drluor □ P8226 But Diluar DP8Z28 Syitam Controllar/Bui Orlvsr DPB233 INS82U I/O Expander tor 48 Serial iNsawi Aiynchronoui Comm. Element OP8251 Prog. Comm. I/O (USART) DP«51 DPB2S5 Pros. Peripheral I/O (PPI) DPS257 Plat. DMA Control DP8259 OPS275 Prog. CRT Controller DPB2I9 Prog. KeyEaard/Dlsplay Intarrice Syitam Timing Elemanl DPSX4 8-Hlt Bl-Dlrectlonil Receiver OP8307 DP831C Octal Latcnecl Peripheral Driver DP8J11 Octal LatcheJ Peripheral Driver 6800/6800 SUPPORT DEVICES - MC6800 MPU MCGS0ZCP MPU with Clock ana RAM 128x8 Static RAM (MC02OJ MC6810API MCGB21 MC6S28 Priority Interrupt Cont 1D24*B-Blt ROM (MCS8A30-S) Synchronous Serial Data Adapter WOOddi Digital MODEM 2W0OPI Mooulator Quad J-State Bui. Trans. (MCBT26) -MICROPROCESSOR CHIPS Z80 (7800 CPU (MKJ880N) (2MH;] Z80A (780-]) CPU (MKMMN-J] |1MH:| CDP1802 CPU 2650 MPU IDM2901ADC CPU— 4-Bil Slice (Com. Temp MCS6502 MPU w/Clock (6SK Bytes Mi INSS03SN-6 MPU-8-Blt [5MHz) INSB0J9N-6 CPU-Sgl.CnipB-BIt [128oyte INSSWON-8 CPU (X6 Bytei RAM) INSS070N CPU-64 Bytes RAM INS8073N CPU w/BasIc Micro Interprc PB0BS CPU -SHIFT REGISTERS- MM510H MM1402N MMM13N MM50MM MMWMN MM50MN 25MV(M04A) 2S1BN Dual 64-Bit Accu 254-Bit Dynamic 1024-Bll Dynamic S00/S]2-Blt Dynar K 33-Bit ■I 132-B Stat SlI-BIt Dynen 1024-Bit Dynamic Dual »0-Blt Static Dual 240-Bit Static Quao 80-Bit Static Fllo (Dual 8QJ -DATA ACQUISITION- Touch Tone LM30SAH LM334Z LM335Z LFJ66N ADC08O4LCN B-BIt DACOeOSLCNS-SIt -DATA ACQUISITION (CONTINUED)- ADCONSCCN ADCD81ICCN OAC1000LCN DAC1008LCN DAC1020LCN DAC1Q22LCN OAC1222LCN C DM141 N B-BIt A/D Converter (B-Ch. H B-BIt A/D Converter (16-Ch. Fv 10-Blt D/A Conv. Micro. Com; 10-Bit D/A Conv. M Icro. Comi 10-Blt D/A Converter (0.05% L 10-Slt D/A Converter (0.20% L 12-BltD/A Converter (0.20% L 256x4 5tatlc Z£x' Static MOS 1024x4 Static 450ns 1024x4 Static 450ns Low Power 1024x4 Static 700ns 1024x4 Static 200ns Low Power 256x1 Static < Dynar c 250ns (MM5290N-4) 4164 64K Dynar MM2I47J 4096x1 Fait JOns 5101 256x4 Static MM5261 1024x1 Dynamic Fully Decoaed MM5762 ?n.l Dynamic MM5280/110J 4096x1 Dynamic MM5290N-? (4!16| I6K Dynamic 150ns (UPD416C-3I MM5298J-3A 8K Dyn. 200ni (lower 'a of MMS290J) B2S2S 64 Bit RAM (16x4) UPD414/MK4027 4K Dynamic 16-pln TM54044-4JNL 4K Static TMS4045 1024x4 Static -PROMS/EPROMS- 2764 Q 5203 82S23 (745188) B2S1JS B2S123(74S28S) 82S1B5 - Over JO M BK EPROM 16K EPROM (-5V, »5V, *12V) 16K EPROM (Single + 5V) 32K EPROM BK EPROM (4S0ns) (Single 45V) 64K EPROM 2048 PROM 32KB PROM (Open Collector) 4096 Bipolar PROM 32xB Trl-State Bipolar PROM BK PROM ire PROMS Listed In Our Catalog - ROM'S Ctlar NMOS READ ONLY MEMORIES" MCM66710P 128x9x7 ASCII Shittea w/Greek MCM66740P 128x9x7 Math SymPol L Pictures DS0025CN OS0026CN INS1771N-1 INS2G51N MM5B167M MM5B174N COP402N COP402MN ■ SPECIAL FUNCTION Dual MOS Clock Driver (SMZ) Dual MOS Clock Driver (5MZ) Floppy Disc Controller Communication Chip Microprocessor Real Time Clock Microprocessor Compatible Clock Microcontroller with 64-Dlglt RAM and Direct LED Drive Microcontroller with 64-Dlglt RAM t. Direct LED Drive w/N Buss Int. 32-Sag.VAC Fluor. Driver (ZO-pIn pkg.) -TELEPHONE/KEYBOARD CHIPS" AY- 5-2376 HD0165-5 74C922 T4C923 MM53190N CMOS Clock Generator Kayooard Encoder (8S keyi) Keyboard Encoder (16 keys) Keyboard Encoaer (16 keyt) Keyboard Encoder (20 keys) Puih Button Pulse Dialer 96/144-Key Serial Keyboard E ELECTRONIC TOY MOTORS T,pc.l TOnouE ftSST — 15 60 30 9.30Q 20 6.7BO 90 0.260 1.30 570 0.97 , 9 , 3 „ 7 ,? D ■ x . MABUCHI RE280 $.99 each 1.201 Length .10/57.50. . .100/S50.00 GLOBAL SPECIALTIES EXPERIIHEDITOR SOCKETS Model Langth Width Chann. Terminal. Strip) P„» EXP4B 6.0" 1.0" n/a n/a 4(160) $ 4.75 EXP300 6.0" 2.1" .3" 84(470) 2(80) SI 2.08 EXP325 1.8" 3.6" 2.1" 2.1" .3" 22(110) 2(20) $ 3.S0 EXP350 .3" 46(230) 2(40) $ E.75 EXP600 6.0" 2.4" .6" 94(470) 2(80) $14.78 EXP65Q 3.6" 2.4" .6" 46(230) 2(40) S 8.75 Quick Test Sockets & Bus Strips .35 1-9 .30 362-812 10-99 .25 100 .39 1-9 .35 473-862 10-99 .30 100 .45 1-9 .39 468-828 10-99 .35 100 .49 1-9 .45 435-802 10-99 .39 100 POWER CORD SALE >* AC and DC Wall Transformers QT-HI 6.5" 6.!" MS $12.50 QTHB B.S" 8.2" 20 S 2.00 QI-47S B.I" 5.0 M S4 SI 0.24 0T-47B QT-1B QTOIf 8J" 5.0" 3.1" 3l" IE S 2.69 To' S B.EO 12 $ 2.25 QT-llS 14" 2.I" 38 9 4.50 or us QT-li QI-JS $10.00 Min. Order - U.S. Funds Only Calif. Residents Add 6% Sales Tax Postage- Add 5%p1us$1 Insurance ELECTRONICS Spec Sheets - 254 Send 86tt Postage for your FREE 1982 JAMECO CATALOG PHONE ORDERS WELCOME (415) 592-8097 MAIL ORDER ELECTRONICS - WORLDWIDE 1355 SHOREWAY ROAD, BELMONT, CA 94002 9/8i PRICES SUBJECT TO CHANGE Part No. Input Output u« wilh clocks. Owtr uipplici or r type ul AC or Price AC 250 117V/60H; 12 VAC 250mA $3.95 AC 500 117V/60Hz 12 VAC 500mA $4.95 AC1000 117V/60Hz 12 VAC 1 amp $5.95 AC1700 117V/60HZ 9 VAC 1.7 amp $3.95 DV 9200 117V/60Hz 9 VDC 200mA $3.25 DC 900 120V/6QHZ 9 VDC 500mA $3.95 CONNECTORS OB25P D-Subminiature Plug S2.9S DB25S D-Subminiature Socket $3.50 D20418-2 Screw Lock Hdwr. (2) DB25S/P » .49 DB51226 Cover for DB2GP/S $1.75 22/44SE P.C. Edge (22/44 Pin) $2.95 UG88/U BNC Plug $1.79 UG89/U BNC Jack $3.79 UG175/U UHF Adapter $ .49 S0239 UHF Panel Recp $1.29 PL258 UHF Adapter $1.60 PL259 UHF Plug $1.60 UG260/U BNC Plug $1.79 UG1094/U BNC Bulkhead Recp $1.29 TRS-80 16K Conversion Kit Expand your 4K TRS-80 System to 16K. Kit comes complete with: * 8 ea. MM5290 (UPD416/4116) 16K Dyn. Rams (" NS) * Documentation for Conversion TRS-16K2 -150NS $29.95 TRS-16K4 -250NS $24.95 JE610 ASCII Encoded Keyboard Kit The JE610 ASCII Keyboard Kit can be interfaced into most any computer system. The kit comes complete with en Industrial grade keyboard switch assembly (62-keys), IC's, sockets, connector, electronic compo- nents and a double-sided printed wiring board. The keyboard assembly requires +5V @ 150mA end —12V 0? 10 mA for operation. Features: 60 keys generate the 126 characters, upper and lower case ASCII set. Fully buffered. Two user-define keys provided for custom applications. Caps lock for upper-case-only alpha charac- ters. Utilizes a 2376 (40-pin) encoder read-only memory chip. Outputs directly compatible with TTL/DTL or MOS logic arrays. Easy interfacing with a 16-pin dip or 18-pin edge connector. Size: 3'A"H x 14W"W x 8%"D JE6107DTE-AK &!&',%??!£, ...$124.95 ir C1 n [/■.+ 62-Key Keyboard, PC Board, * -w n nt - JtO IU Kit & Components (no case) $ /y.y5 K62 62-Key Keyboard (Keyboard only) . . .$ 34.95 DTE-AK (case only — 3V*"Hxir'Wx8*."D)$ 49.95 JE212 - Negative 12VDC Adapter Board Kit NEW!? for JE610 ASCII KEYBOARD KIT Provides-12VDC from incomingSVDC . .$9.95 JE600 Hexadecimal Encoder Kit FULL 8-BIT ^k\ LATCHED OUTPUT M V^K \ 19-KEY KEYBOARD W * ^M^ \ 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 readouts. Also included isa key entry strobe. Features: Full B-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-pin IC connector. Only +5VDC required for operation. Size: 3«"H x 8V."W x 8K"0 JE600/DTE-HK ^j&'^TSSS) .... $99.95 icenn i/.* 19-Key Hexadec. Keyboard. tf-CQ QC JbOUU IXII PC Board LCmpnts. (no case}. ,QKKf.9D K19 19-Key Keyboard (Keyboard only) .... $14.95 DTE-HK (case only —3Vi M Hx8W."Wx8V«"D) $44. 95V Circle 180 on inquiry card. BYTE September 1981 487 *v £*> v "THE BIG BOARD" OEM - INDUSTRIAL - BUSINESS - SCIENTIFIC SINGLE BOARD COMPUTER KIT! Z-80 CPU! 64K RAM! *%, THE FERGUSON PROJECT: Three years in the works, and maybe too good to be true. A tribute to hard headed, no compromise, high performance, American engineering! The Big Board gives you all the most needed computing features on one board at a very reasonable cost. The Big Board was designed from scratch to run the latest version of CP/M*. Just imagine all the off-the-shelf software that can be run on the Big Board without any modifications needed! Take a Big Board, add a couple of 8 inch disc drives, power supply, an enclosure, CRT., and you have a total Business System for about 1/3 the cost you might expect to pay. FEATURES: (Remember, all this on one board!) $ 649 00 < 64K K|T BASIC I/O) FULLY SOCKETED! SIZE:8'Ax 13% IN. SAME AS AN 6 IN. DRIVE. REQUIRES: »5V @ 3 AMPS + - 12V @ .5 AMPS. 64K RAM 24 x 80 CHARACTER VIDEO Uses Industry standard 4116 RAM'S. All 64K Is available to the user, our VIDEO and EPROM sections do not make holes in system RAM. Also, very special care was taken in the RAM array PC layout to eliminate potential noise and glitches. Z-80 CPU With a crisp, flicker-free display that looks extremely sharp even on small monitors. Hardware scroll and full cursor control. Composite video or split video and sync. Character set Is supplied on a 2716 style ROM, making customized fonts easy. Sync pulses can be any desired length or polarity. Video may be inverted or true. 5x7 Matrix - Upper & Lower Case Running at 2.5 MHZ. Handles all 4116 RAM refresh and supports Mode 2 INTERUPTS. Fully buffered and runs 8080 software. FLOPPY DISC CONTROLLER SERIAL I/O (OPTIONAL) Full 2 channels using the Z80 SIO and the SMC 8116 Baud Rate Generator. FULL RS232! For synchronous or asynchronous communication. In synchronous mode, the clocks can be transmitted or received by a modem. Both channels can be set up for either data-communication or data-terminals. Supports mode 2 Int. Price for all parts and connectors: $85. Uses WD1771 controller chip with a TTL Data Separator for enhanced reliability. IBM 3740 compatible. Supports up to (our 8 inch disc drives. Directly compatible with standard Shugart drives such as the SA800 or SA801. Drives can be configured for remote AC off-on. Runs CP/M* 2.2. TWO PORT PARALLEL I/O (OPTIONAL) , Uses Z-80 PIO. Full 16 bits, fully buffered, bi-directional. User selectable hand shake polarity. Set of all parts and connectors for parallel I/O: $29.95 BASIC I/O Consists of a separate parallel port (Z80 PIO) for use with an ASCII encoded keyboard lor input. Output would be on the 80 x 24 Video Display. REAL TIME CLOCK (OPTIONAL) Uses Z-80 CTC. Can be configured as a Counter on Real Time Clock. Set of s parts: $14.95 64K RAM KIT SYSTEM C DMPARISON Talk about bangs per buck! The prices shown for S100 kits were taken from the July 1980 BYTE. This will give some basis for comparison between the Big Board and a similar system implementa- tion on the S100 Buss. B0 X 24 Video Kit 365.00 235.00 Z-80 CPU Kit . . 185.95 SER & PAR. I/O 129.95 45.00 SUB TOTAL $1330.90 CP/M* 2.2 FOR BIG BOARD The popular CP/M" D.O.S. modified by MICRONIX SYSTEMS to run on Big Board is available for $150.00. PC BOARD Blank PC Board wilh Rom Set and Full Documentation. $199.00 PFM 3.0 2K SYSTEM MONITOR The real power of the Big Board lies in its PFM 3.0 on board monitor. PFM commands include: Dump Memory, Boot CP/M*, Copy, Examine, Fill Memory, Test Memory, Go To. Read and Write I/O Ports, Disc Read (Drive, Track, Sector), and Search. PFM occupies one of the four 2716 EPROM locations provided. Z-80 is a Trademark of Zilog. Digital Research Computers ** (OF TEXAS) ' P.O. BOX 401565 • GARLAND, TEXAS 75040 • (214) 271-3538 TERMS: Shipments will be made approximately 3 to 6 weeks after we receive your order. VISA, MC, cash accepted. We will accept COD's (for the Big Board only) with a $75 deposit. Balance UPS COD. Add $3.00shipping. USA AND CANADA ONLY •TRADEMARK OF DIGITAL RESEARCH. NOT ASSOCIATED WITH DIGITAL RESEARCH OF CALIFORNIA, THE ORIGINATORS OF CPM SOFTWARE "1 TO 4 PIECE DOMESTIC USA PRICE. cjrc|e 1 1(J on inquiry card . DIGITAL RESEARCH COMPUTERS (214)271-3538 32K S-100EPROM CARD NEW! $79,95 KIT USES 2716s Blank PC Board - $34 ASSEMBLED & TESTED ADD $30 SPECIAL: 2716 EPROM's (450 NS) Are $9.95 Ea. With Above Kit. 7. Any or all EPROM locations can be disabled. 8. Double sided PC board, solder-masked, silk-screened 9. Gold plated contact fingers. 10. Unselected EPROM's automatically powered down for low power. 11. Fully buffered and bypassed. KIT FEATURES; 1 Uses +5V only 2716 (2Kx8) EPROM's 2 Allows up to 32K of software on line 1 3 IEEE S-100 Compatible. 4. Addressable as two independent 16K blocks. 5. Cromemco extended or Northstar bank select. 6 On board wait state circuitry if needed. 12. Easy and quick to assemble. 32K SS-50 RAM $ 299 00 k,t For 2MHZ Add $10 „.'.. .JBiiHlti ■■■HBIIB fc . v . -IBBBBBC) RMHUttHBM jLL'iftMilHB »■«■■■■■ E-' HI1HHBH BMUHtiHHi Blank PC Board $50 For SWTPC 6800 - 6809 Buss Support IC's and Caps $19.95 Complete Socket Set $21.00 Fully Assembled, Tested, Burned In Add $30 At Last! An affordable 32K Static RAM with full 6809 Capability. FEATURES: 1. Uses proven low power 2114 Static RAMS. 2. Supports SS50C - EXTENDED ADDRESSING. 3. All parts and sockets Included. 4. Dip Switch address select as a 32K block. 5. Extended addressing can be disabled. 6. Works with all existing 6800 SS50 systems. 7. Fully bypassed. PC Board is double sided, plated thru, with silk screen. 16K STATIC RAM KIT-S 100 BUSS PRICE CUT! $ 169 9 ?, T JIIIIIIIIIEIIIIII IllllllIIIIIIIIII 16K STATIC RAM SS-50 BUSS PRICE CUT! I II *159 KIT liilllllilllllll i iiiiiiiiiiiiiii FULLY STATIC! BLANK PC BOARD W/DATA-$33 LOW PROFILE SOCKET SET-$12 SUPPORT IC'S & CAPS-$19.95 KIT FEATURES: - 1. Addressable as four separate 4K Blocks. 2 ON BOARD BANK SELECT circuitry. (Cro- memco Standard 1 ). Allows up to 512K on line! 3 Uses 21 14 (450NS) 4K Static Rams 4. ON BOARD SELECTABLE WAIT STATES 5. Double sided PC Board, with solder mask and silk screened layout. Gold plated contact fingers 6. All address and data lines fully buffered ASSEMBLED & TESTED-ADD $35 7. Kil includes ALL parts and sockets 8. PHANTOM is jumpered to PIN 67. 9 LOW POWER: under 1.5 amps TYPICAL from the *8 Volt Buss 10. Blank PC Board can be populated as any multiple of 4K. FOR 2MHZ ADD $10 ■ - ■ . . .. FOR SWTPC 6800 BUSS! OUR #1 SELLING RAM BOARD! ASSEMBLED AND TESTED - $35 KIT FEATURES 1 Addressable on 16K Boundaries 2 Uses 2114 Static Ram 3. Fully Bypassed 4 Double sided PC Board Solder mask and silk screened layout 5 /^'l Parts and Sockets included 6 Low Powei ' Under 1 5 Amps Typical BLANK PC BOARD— $35 COMPLETE SOCKET SET— $12 SUPPORT IC'S AND CAPS— $19.95 «#» STEREO! %n„ S-100 SOUND COMPUTER BOARD COMPLETE KIT! $3495 (WITH DATA MANUAL) At last, an S-100 Board that unleashes the full power of two unbelievable General lnstrumentsAY3-8910NMOS computer sound IC's. Allows you under total computer control to generate an infinite number of special sound effects for games or any other program. Sounds can be called in BASIC, ASSEMBLY LANGUAGE, etc. KIT FEATURES: * TWO Gl SOUND COMPUTER IC'S. * FOUR PARALLEL I/O PORTS ON BOARD. * USES ON BOARD AUDIO AMPS OR YOUR STEREO. * ON BOARD PROTO TYPING AREA. * ALL SOCKETS. PARTS AND HARDWARE ARE INCLUDED. » PC BOARD IS SOLDERMASKED, SILK SCREENED, WITH GOLD CONTACTS. * EASY. OUICK. AND FUN TO BUILD. WITH FULL INSTRUCTIONS. * USES PROGRAMMED I/O FOR MAXIMUM SYSTEM FLEXIBILITY. Both Basic and Assembly Language Programming examples are included SOFTWARE: SCL™ is now available! Our Sound Command Language makes writing Sound Effects programs a SNAP! SCL™ also includes routines for Register-Examine-Modify, Memory-Examine- Modify, and Play-Memory. SCL™ is available on CP/M' compatible diskette or 2708 or 2716, Diskette - $24.95 2708 - $19.95 2716 - $29.95. Diskette includes the source. EPROM'S are ORG at E000H (Diskette Is 8 Inch Soft Sectored) BLANK PC BOARD W/DATA $31 SPECIAL PURCHASE! UART SALE! TR1 602B - SAME AS TMS601 1 , AY5-1 01 3, ETC. 40 PIN DIP TR1602B $ 2 95 EACH 4 For $10 00 CRT CONTROLLER CHIP SMC #CRT 5037. PROGRAMMABLE FOR 80 x 24, ETC. VERY RARE SURPLUS FIND. WITH PIN OUT. $12.95 EACH. 4K STATIC RAM National Semi. MM5257. Arranged 4K x 1. +5V, 18 PIN DIP. A Lower Power, Plug in Replacement for TMS 4044. 450 NS. Several Boards on the Market Will Accept These Rams. SUPER SURPLUS PURCHASE! PRIME NEW UNITS! 8 FOR $16 32 for $59.95 I Digital Research Computers 9 (OF TEXAS) ' P.O. BOX 401565 • GARLAND, TEXAS 75040 • (214) 271-3538 NEW! G.I. COMPUTER SOUND CHIP AY3-8910. As featured in July. 1979 BYTE 1 A fantastically powerful Sound & Music Generator. Perfect for use with any 8 Bit Microprocessor. Contains 3 Tone Channels. Noise Generator. 3 Channels of Amplitude Control. 16 bit Envelope Period Control, 2-8 Bit Parallel I/O. 3 D to A Converters, plus much more' All in one 40 Pin DIP. Super easy interface to the S-100 or other busses. $11.95 PRICE CUT! SPECIAL OFFER: $44^5 each Add $3 for 60 page Data Manual. TERMS: Add $2.00 postage. We pay balance. Orders under $15 add 75-.^» — ••• ■■....■....■•■..•■ ....... S149.0p Micromouth iof use ol.TJjS-^ Model 1 eairrpifite with cable,- AC Adapter, less^enoipsure A81T. MM-94VOTRS! UL.i. ........,....:„;:..„:...........„. $169.00' Expansion Interface tor TRS-80 Model 1 with DATA SEPARATOR," 32K-. b( : RAM, and Cenfrortcs Ertater port. AStT. Fegturediri MARCH BYTE. M&H-DISK80 $429.60 I/O Interface fpr TRS-80, Features" 50-19200 baud KS-232G Serial port and Centronics printer port. Connect up to 16 '.COtiJMWs to either Keyboard 6r''Exr^.nslbn"Jnt€irfaC.e. Fearuiea'in.Juhe BO BYTE Mlllk;dl«-*b~.y..:.™,.^,........., .....,„.....;. SW9O0 A !' Extender Board . S30.00 LE PRODUCTS MORROW HARD DISK MDSM26S 26 MB S-lOO Subsystem LISTPRICE $4495.00 SALE PRICE $3495.00 B & K OSCILLOSCOPE ccs 22 ° OA BKPI405 5 MHZ S. T. LISTPRICE $315.00 SALE PRICE $280.00 BKP1420 15 MHZ D.T. Portable.. UST PRICE $825.00 ,. SALE PRICE S750.OO BKP1530 30 MHZ D.T. _-.—,« VarL Delayed LIST PRICE $136500 TEMC5U3 SALE PRICE CALL BXPUOO lOOMHZQT. T Vart. Delay LIST PRICE $2575.00 SALEPPJCE CAM. jg^^ B & K TEST EQUIPMENT ^^ BKP3010 Function Generator LIST PRICE $220.00 ___,_„, OUR PRICE S198.00 ™ n ™° BKP3020 Sweep/Funct.Generator LIST PRICE $379.00 OUR PRICE $349.00 teirfdo KP3300 5 MHZ Pulse Generator.... LIST PRICE $350.00 SALE PRICE $320.00 VISTA APPLE PRODUCTS smJSOIK VIS150 Type Ahead Butter LIST PRICE $49.95 SALE PRICE $44.95 VTSA800 8" Floppy Controller LIST PRICE $595.00 CA, AX, HI ORDER (213) 709-5464 CCS MAINFRAMES S-10012slot UST PRICE $43400 OUR PRICE $410.00 TEI MAINFRAMES 12 slot desk UST PRICE $68500 OUR PRICE $615.00 22 slot desk UST PRICE $845.00 OUR PRICE $760.00 12 slot rack mount LIST PRICE $80000 OUR PRICE $720.00 22 slot rack mount LIST PRICE $94500 OUR PRICE $850.00 801R desk LISTPRICE $53500 OUR PRICE S485.00 SOlRdesk UST PRICE $725.00 OUR PRICE $670.00 8" DISK DRIVES D/Dens s/Slded REG PRICE $495.00 SALE PRICE $425.00 2/S39S.OO — D/Dens D/Slded Each $625.00 IEEE-488 Interface IS, 2P Interface 3" ....:. Assembled 8c Tested . ...UST PRICE $475.00 SALE PRICE S415.00 .... UST PRICE $175.00 SALE PRICE $165.00 ...LIST PRICE $225100 SALE PRICE $185.0© SALE PRICE S550.00 2 or more $600.00 «a. PRIORITY ONE ELECTRONICS t» ^ 9161-B DEERING AVE. • CHATSWORTH, CA 91311 lU Iw ORDER TOLL FREE (BOO) 423-5922 CA, AK, HI CALL (213) 709-5464 ~ rn * terms, US., VISA. MC. BAG. (Shock Money 1 . Order. US Funds Only. CA residents add 6% Sales Tax. MINIMUM PKEPAID ORDER S15.CO. include MINIMUM SHtPPING.St HANDLING ot $2.50 lot the first 3 lbs., plus 25e lor each additional pound. Orders over 50 lbs. sent freight, collect. Just in case, please Include your phone no. Prices subject to change without notice. We will do our best to main- ■ tain prices thru-September 195L SOCKET and CONNECTOR prices based on GOLD, not exceeding $700.00 per or Sales Prices Valid only if *OU mention publication and month. Credit Card orders will be charged appropriate freight. Circle 299 on Inquiry card. '////AT^S, S-lOO ROM FBI PHOM PROGRAMMER - SSM 'programs 2708 or 2716's, operates as a 4KI8K EPROM board as well. SSMPB1K Kit $154.95 SSM-PB1A A&T $219.00 ECONOROM 2708 ■ QODBOUT 16K x 8 EPROM Board using 2708, Power on jump to any 256 byte GBT 125U GBT 125A GBT 125C UnKit . A&T. . CSC. . $85.00 $120.00 $175.00 GBT 171A GBT 171C GBT CPM80 GBT CPM86 S-lOO CPU CPU-Z - QODBOUT 214 MHZ Z80 CPU 24 Bit Addressin, GBT 160U UnKit $225.00 GBT160A A&T $199.01 GBT160C CSC 3-6 MHZ $375.00 S-lOO DISK CONTROLLERS DISK 1 ■ QODBOUT DMA, Soft Sector, Controls 8" or S'A", single or double density AST $450.00 CSC $556.00 CP/M 2.2 lor Z80/8085 with Manuals & BIOS 8" S.D. disk $175.00 CP/M tor 8086 with manuals & BIOS 8" SID disk $300.00 2422A ■ CA. COMP. SYST. I/O Mapped, controls 8" or 5'/.", single or double density CCS-2422 A&T with CPM 2.2 8" S.D... . DISK JOCKEY 1 - MORROW . M Single density disk controller with \\ serial I/O, controls 8" I..DSDJ1108 A&T DISK JOCKEY 2D - MORROW I/O Mapped, controls 8", single or double density, serial t/0 DSDJ2208 A&T r $365.00 $219.00 $375.00 DUAL PROCESSOR 8085-8088 ■ QODBOUT 5 MHZ Provides true 16 Bit Power with a standard 8 bit S-100 GBT 1612U GBT 1612A GBT 1612C GBT161U GBT161A GBT161C bus UnKit $295.00 A&T $399.00 CSC $498.00 BOARD WITH 8085 ONLY UnKit $235.00 A&T $305.00 CSC $399.00 2610 Z80 CPU-CA. COMP. SYST. 2/4 MHZ Z80A CPU with RS-232C Serial I/O Port complete with Monitor PROM for 2422 Disk Controller CCS 2810 A&T..- $280.00 CBS ZSO CPU - S.S.M. 2/4 MHZ will accept 2716, or 2732, or RAM RUN/STOP and single step switches SSMCB2K Kit $260.00 SSMCB2A A&T $310.00 SSMZ80M SSM Z80 Monitor $89.00 CBIA SOSO CPU - S.S.M. 8080CPU, 1K RAM, Holds 1 2708, 1 8 Bit parallel input port. SSMCB1A Kit $183.00 SSMCB1A A&T $225.00 SSM8080M SM 8080 Monitor $59.00 S-IOORAM 64K STATIC RAM - QODBOUT RAM 17, 10 MHZ, 2 Watt, DMA Compatable GBT-175A48 A&T48K $950.00 GBT-175C48 CSC 48K $1050.00 GBT-175A64 A&T 64K $900.00 GBT-175C64 CSC 64K $1395.00 64K DYNAMIC RAM ■ CCS 4 MHZ, on board refresh, DMA compatable, 24 bit address. CCS-2065A A&T $599.00 32K STATIC RAM • QODBOUT RAM 20 10 MHZ, 4K byte block disable, available 16, 24, or 32K GBT-164A16 A&T 16K $319.00 GBT-164C16 CSC 16K $418.00 GBT-164A24 A&T 24K $449.00 GBT-164C24 CSC 24K $539.00 GBT-164A32 A&T 32K $499.00 GBT-164C32 CSC 32K $720.00 32K STATIC RAM - CCS 4 MHZ, Bank select, 8/16 bit data CCS-2032 A&T 32K $599.00 16K STATIC RAM - GODBOUT RAM 14, 10 MHZ, 24 bit addressing GBT-143A A&T 16K $169.00 GBT-143C CSC 16K $399.00 16K STATIC RAM - CCS 4 MHZ, 8/16 bit data, bank select CCS-2116A A&T 16K $299.00 BK STATIC RAM - QODBOUT Econoram II 2MHZ, 8K, No doubt, the most popular S-100 RAM ever built. GBT-114U UnKit 8K $99.95 DISK DRIVES SOIR - SHUQART Single sided double density most popular 8" drive SHU80IR $425.00 ea. or 2 or more $395.00 SHUSA80IRM Manual for 80IR drives $10.00 DT-8-QJUME Data track 8 double sided, double density QMEDT8 $625.00 ea. or 2 or more $600.00 DISK CABINETS V-lOO ■ VISTA Dual 8" drive cabinet with power supply. Rack or Desk Mount VIS-V100 $395.00 SINGLE 8" Q.T. Single 8'* cabinet with power supply QTCDDC8 $195.00 VIS-9801 VIS-9802 5" CABINETS • VISTA Single 5" with P.S Dual 5" with P.S $75.00 $95.00 S-lOO DISK SUBSYSTEMS DISCUS SINGLE SIDES MORROW 8" DBL Density drives with cabinet, power supply controller, with CP/M 2.2 and Microsoft Basic MDSF1218 Single Drive System $950.00 MDSF1228 Dual Drive System $1598.00 DISCUS DOUBLE SIDED - MORROW 8" DBL Density/sided drives with cabinet Power supply controller, with CP/M 2.2 and Microsoft .Basic MDSF2218 Single Drive System $1250.00 MDSF2228 Dual Drive System $2195.00 26MB HARD DISK - MORROW Special purchase, limited stock - 26MB formatted hard disk complete with cabinet, P.S., Controller, CPM 2.2 and Microsoft Basic MDS-M26S 26 MB Subsystem List $4495.00 SALE • $3495.00 • SAVE $1,000.00 MICROPOLIS Priority 1 Electronics is the worlds largest distributors of MICROPOLIS disk sub Systems CALL FOR PRICES htfgSfr* PRIORITY S-lOO I/O BOARDS SYSTEM SUPPORT 1 - QODBOUT Serial port /software prog baud), 4K EPROM or RAM provision, 15 levels of interrupt, real time clock, optional math processor GBT-162U UnKit $295.00 GBT-162A A&T $360.00 GBT-162C CSC $460.00 GBT-9512 Math Chip $195.00 MPX CHANNEL BOARD - QODBOUT I/O Multiplexer, using 8085A-2 cpu on board GBT-166A GBT-166C GBT- 133 A GBT-133C $450.00 $550.00 A&T. CSC INTERFACES I - QODBOUT Two Serial I/O A&T $219.00 CSC $298.00 INTERFACES U - QODBOUT Three parallel, one serial I/O board GBT-150A A&T $219.00 GBT-150C CSC $298.00 MULTI I/O - MORROW DESIGNS Three Serial, Two parallel MDSMB3200 A&T $309.00 SWITCHBOARD-MORROW DESIGNS Two serial I/O, four parallel I/O, one status port, one strobe port MDSSB2411 A&T $239.00 1/02 - SSM One parallel input, one parallel output, proto work area Kit $69.00 A&T $89.00 I/04 - SSM Two serial I/O, two parallel I/O Kit $210.00 A&T $260.00 SBI-SSM Music synthesizer board Kit $249.00 AST $310.00 Software $ 25.00 S-lOO VIDEO BOARDS SPECTRUM ■ QODBOUT Color Graphics board with Parallel I/O. GBT-144U UnKit $299.00 GBT-144A A&T $349.00 GBT-2D Sublogtc Software $ 35.00 VB ■ 3 S.S.M. 80 x 24 or 48 character video display Memory Mapped, Parallel Keyboard port SSMVB3K24 Kit 80x24 $349.00 SSMVB3A24 A&T 80x24 $429.00 SSMVB3UP Upgrade Kit $30.00 VB2-SSM I/O Mapped Video Board, with Parallel Keyboard port. 64x16 SSMVB2K Kit $169.00 SSMVB2A A&T $229.00 VBIC - SSM Memory Mapped Video Board 64x16 character display or 64x16 graphics dlslplay SSMVBICK Kit $169.00 SSMVBICA A&T $220.00 S-lOO MOTHERBOARDS MOTHERBOARD • QODBOUT Active termination, 6-12-20 slot SSMI02K SSMI02A SSMI04K SSMI04A SSMSBIK SSMSBIA SSMSBIS GBT-153U GBT-153A GBT-154U GBT-154A GBT-155U GBT-155A Unkit 6 slot $ 89.00 A&T 6 slot $119.00 Unkit 12 slot. A&T 12 slot. . Unkit 20 slot. A&T 20 slot.. $129.00 $149.00 $174.00 $189.00 SSMOB1K SSMOB1A ELECTRONICS WUNDERBUSS - MORROW DESIGNS Active termination, 8-12-20 slot, peripheral power outputs (5V@1A, 12V @ 500ma, - 12V SOOrnal MDS0800A A&T 8 slot $129.00 MDS1200A A&T 12 slot $149.00 MDS2000A A&T 20 slot $199.00 S-lOO MISC. CK017 ACTIVE TERMINATOR-GODBOUT GBT-106U Kit $ 34 :< 2520 - CCS Extender/terminator, Active and/or passive CCS2520AK Kit $ EXTENDER/LOGIC PROBE-MULLEN MUL-CK004 Kit $ 59.00 OBI VECTOR JUMP - SSM with prototyping area Kit $ A&T $ 65.00 90 00 9161-B DEERING AVE. • CHATSWORTH, CA 91311 *fc*8W Terms. U.S., VISA. MC. BAC, Check Money Order, U.S. Funds Only. CA residents add 6% Sales Tax. MINIMUM PREPAID ORDER $15.00. Include MINIMUM SHIPPING & HANDLING ol S2.50 lor the first 3 lbs., plus 25C lor each additional pound. Orders over 50 lbs. sent freight, collect. Just In case...please include your phone no. Prices subject to change without notice. We will do our best to maintain prices thru September 1981. SOCKET and CONNECTOR prices based on GOLD, not exceeding S700.00 per oz. Sales Prices Valid only if YOU mention publication and month. Credit Card orders will be charged appropriate freight. wftmm _ " Ctrcf, e 300 on inquiry card. STAR MODEM FROM LIVERMORE LIST PRICE lo 300 baud data rate. Compatible IW""«UU with Bell 103 and 113. Answer/ SALE PRICE Originate. Full/Half Duplex. Special £l^}f\ f\^\ sell test features. »J> L&7.\J\*/ RS232 and "D" SUB-MINIATURE CONNECTORS 5B i|l|l|i|iiMii|i|i "T MALE T uuuuuiiffrrntTn' 1 1 [EliAIC r ' P= Plug, Male Type • S- Socket. FemaleType-C= Cover, Hood PART NO. CND-DE9P CND-DE9S CND-DE9C CND-DA15P CND-DA15S CND.DA15C CND-DB25P CND-DB2SS CND-DB51212 CND-P25H CND-DB51226 CND-DC37P CND-DC37S CND-DC37C CND-DD50P CND-DD50S CND-DD50C CND-D2D41B CND-RS2328F CND-5730360 DESCRIPTION 9 pin male 9 pin lemale 9 pin cover 15 pin male 15 pin female 15 pin cover 25 pin male 25 pin lemale 1 pc. grey hood 2 pc. grey hood 2 pc. block hood 37 pin male 37 pin lemale 37 pin cover 50 pin male 50 pin female 50 pin cover Hardware set 2 pr. RS232, DB25P, EIA Glass 1 cable 8 con. 8 II Cent. 700 Series Printer connector 1-9 S 2.1D S 2.70 $ 1.50 S 2.75 S 3.95 S 1.50 S 3.50 S 4.60 S 1.60 S 1.50 $ 1.90 S 5.80 S 8.70 S 1.80 S 8.75 SI 1.65 S 2.00 S 1.00 PRICE 10-24 S 1.90 S 2.40 S 1.25 S 2.45 S 3.80 $ 1.30 S 3.25 S 4.35 $ 1.45 S 1.25 S 1.65 J 5.10 S 7.70 S 1.55 S 7.75 S10.25 S 1.80 S .80 25-99 $ 1.70 S 2.10 $ 1.10 $ 2.15 S 3.20 S 1.10 S 3.00 S 4.20 S 1.30 S 1.10 $ 1.45 S 4.45 S 6.70 S 1.30 S 6.70 S 8.90 S 1.60 S .70 S19.95 S17.95 S15.95 $ 9.00 S 7.50 S 6.00 MICROCOMPUTER PRODUCTS PART NO. 2016P3 2114N3L 5257N3L 2732 2716 2708 PRICE 8/SI00.00 8/S28.00 8/$50.00 8/S120.00 8/S50.00 8/S32.00 8080 SERIES PART NO. PRICE 6502 SERIES PART NO. PRICE INS Btldil A INS 8085A DP8212N DP8214N DP8216N DP8224N DP8224-4N DP8226N DP8228N DP8238N INS8250N INS8251N INS8253N INS8255N INS8257N INS8259N INS827SN INS8279N S5.50 S19.95 S2.95 $5.25 S2.95 $3.25 S3. 95 S3.50 $5.55 $5.55 $15.00 $7.50 $17.95 $6.80 $16.45 $18.00 $59.95 $49.95 6S02 6502A 6520 6522 6530-002 6530-003 6530-004 6530-005 6532M 655 1M $12.95 $18.95 $8.95 $10.95 $21.95 $21.95 $21.95 $21.95 $21.95 $21.95 6800 SERIES PART NO. PRICE Z80 SERIES Z80A S14.95 280AP10 $14.95 Z80ACTC S13.95 Z80ADMA S45.00 Z8OAS1DO $59.95 Z80ASIU1 S59.95 Z80AS102 $59.95 FLOPPY DISC CONTROLLER MC6800P MC6802P MC6808P MC6809P MC6821P MC6828P MC6840P MC6845P MC6847P MC6850P MC6852P MC6854P MC6860P MC6862P MC6875L MC66710P MC66750P UARTS PART NO AY51013A TR1602B TR1863 IM6402 $11.95 $17.95 $9.95 $34.95 $5.95 $14.95 $14.95 $31.00 $14.95 $5.41 S5.79 $24.95 $10.89 $12.00 $7.40 $12.50 $12.50 PRICE $5.95 $5.95 $6.95 $7.95 FD1771B-01 FD1791B-01 $24.95 $44.95 CompuPro" GBT-143A List $349.00 - VBSR 10 MHZ 16K A&T STATICS- 100 RAM $169.00 Ea J3/$450.00 • Operates up to 10 MHZ (90 ns RAM Chips) • Assembled & Tested • Meets or exceeds all IEEE 696/S-100 specifications (including timing). • Fully static design eliminates the timing problems associated with dynamic memories. • Switch selectable choice of 24 address lines conforming to the IEEE 696/S-100 extended addressing specifications, or 16 address lines as used in older S-100 systems. • Ideal for multi-user installations. • Board is addressable as one 16K x 8 block on any 4K boundary. • Switch selectable PHANTOM disable and write protect. • + 5 Volt operation (requires no other supply voltages). • Low power operation (900 mA typical, 1200 mA maximum).' 1 year Factory Warranty. Plugboards sfmMiiwniw S-100 "ANY DIP" has lull power and ground planes back to back. Boards accommodates .3. .4. .6. .9" D: 1-4 5-9 10-24 $24.67 $22.34 $20.02 APPLE PLUGBOARD Vector 4609 Peripheral Interlace Plugboard for construction of custom circuits. Plug compatible with Apple II. Commodore PET and Super Kim microcomputers. VCT-4609 1-4 5-9 10-24 $20.74 $18.79 $16.84 Universal Microcomputer/ processor plugboard use with S-100 bus. Complete with heal sink & hardware. 53" x 10" x 1/16". 1-4 5-9 10-24 S22.48 S20.37 $18.26 VCT-8801-1 Same as 8800V except plain, less power buses & heat sink. 1-4 5-9 10-24 S15.67 S14.24 S12.82 <4.5" (4.5" VCT-3682 9.6" ■ S13.63 VCT-3862-2 6.5' 511.04 Hi-Density Dual-In-Line Plug- board lor Wire Wrap with Power & Grd. Bus Epoxy Glass 1/16" 44 pin con. spaced 156 VCT3677 9.6"x4.5" VCT-3667 96" x 4.5" S13.33 VCT-3677-2B.5"x4.5" S10.68 Gen. Purpose D.I. P. Boards with Bus Pattern for Solder or Wire Wrap Epoxy Glass 1/16" 44 pin con. spaced .156 WiAMflJWJUUUAtMflU VCT-3662 6.5"x4.5" $8.69 VCT-3662-2 9.6" x 4.5" S10.B5 VCT-3690-12 $26.64 CARD EXTENDER Card Extender has 100 contacts 50 per side on .125 centers Attached connector-is CDmpati P pattern plugboards lor IC's Ex- ble with S-100 Bus Systems, poxy Glass 1/16" 44 pin con VCT-3690 6.5" 22/44 pin spaced. 156 .156 ctrs. Extenders ...515.66 1/16 jfes* BOARD .042 diaholes on 0. 1 spacing for IC's Phenolic PART NO. VCT-64P44-X VCT-169P44-X Epoxy Glass VCT-64P44 VCT-84P44 VCT-I69P44 VCT-I69P48 SIZE 4.5" x 6.5" 4.7" x 17" PRICE 1-9 10-19 x6.5" x8.5" x 17" x 17" S1.56 $3.69 $1.83 $2.25 $4.61 $9.00 $1.40 $3.32 $1.65 $2.03 S4.15 SB. 10 ZERO INSERTION FORCE TEST SOCKETS 2 TRS-80/APPLE MEMORY EXPANSION KITS 4116'sRAMS from Leading Manufacturers (16Kxl 200) 8 for $20. 00 Add $3.00 for programming Jumpers for TRS-80 Keybaord 7 r:5^ POWERLINE INSOLATOR GOF-IBARW3 SH.WT. 3 lbs. List Price $59' 5 Sale Price $29.00 A MUST FOR EVERY OFFICE WITH DATA PROCESSING EQUIPMENT 1-9 S 5.50 S 7.50 S10.25 TTTTTTr 10-24 $5.35 $7.25 $9.85 •I iff 25-99 $4.95 $6.95 $9.50 I ■*«>>'. 6 OUTLET MULTI USE CORD REEL SEND $l ao for 60 Page CATALOG HSfc SH. WT. 5 LBS. G0F-CR1 22 It. Cord $24.95 GOF-CR50 50 It. Cord $39.95 SPECIAL PURCHASE GOLD Q^lBFINLOW PROFILE LC. C-35 BOOKETS TIG-16LP P kg.ofioo TIG-16LP P kg.oiiooo SI20.0C OEMS Stock up at this LOW PRICE 1M-10A List $104.95 SPECIAL $69.95 with tube Perfectly balanced fluores- cent lighting with precision magnifier lens. Tough thermoplastic shade. Easy lens removal. New wire clip design permits easy instal- lation and removal of flourescent tube. Comes LEDU with plastic shield to pro- tect tube from soiling and damage. Colors: Gray. Black, and Chocolate Brown. Comes with one 22 watt T-9 Circline iluorescent tube, 3 diopter lens. 10 lbs. PRIORITY I ONE I ELECTRONICS 9161-B DEERING AVE. • CHATSWORTH, CA 91311 ORDER TOLL FREE (800) 423-5922 CA, AK, HI CALL (213) 709-5464 Terms, U.S.. VISA, MC, BAG Check Money Order, U.S. Funds Only. CA residents add 6% Sales Tax. MINIMUM PREPAID ORDER SJ5.0O. Include MINIMUM SHIPPING 8c HANDLING ol S2.50 lor the Hist 3 lbs, plus 25C lor each additional pound. Orders over 60 lbs. sent freight, collect. Just In case.please Include your phone no. Prices subject to change without notice. We will do our best to main- tain prices thru September 1981. SOCKET and CONNECTOR prices based on GOLD, not exceeding S700.00 per oz. Sales Prices Valid only If YOU mention publication and month. Credit Card orders will be charged appropriate lreighl. Circle 300 on inquiry card. Unclassified Ads FOR SALE: TRS-80 Mode! I Level II with 16 K memory, lowercase installed, in mint condition. Including S200 system desk, manual and computer books, and complete library of games and software (including Scnpsit package) worth S300. Complete system worth over SI 400 for only SI000. Mike Clary. 3008 E Meadow Grove Rd, Orange CA 92667. [7I4J 998-0155. FOR SALE: Netronics ELF II microcomputer with 8 K pro- grammable memory. RS-232 interface, cassette-tape interface, Netronics video terminal. Motorola video monitor, Tiny BASIC on cassetre. and full documentation. S400 (price negotiable). Mike Heitmann. 11 4 S Overbrook. St Charles MO 6330 1, (3 14] 723-3950 weekends or after 4:30 weekdays. FOR SALE: DEC/Heath H-l 1 16-bit computer. DEC LSI- 1 1 16-bit processor with floating-point processor option, 56 K [28 KW, 16-bit) MOS memory, serial port (20 mA or RS-232), dual 8-inch disk drive, disk operating system, FORTRAN compiler, and BASIC Spare parts include LSI- 1 I processor card, Memorex 8-inch disk drive, disk controller, memory, and disk controller parts. Cables, service manuals, and operation manuals. New cost over S 10,500. Sell for S6000. Mike, (61 2) 920-2440. FOR SALE: IBM/Escon Selectnc typewriter (correcting, with legal keyboard). Eighi months old. Factory-installed RS-232C in- terface with backspace and tab. In new condition, too slow for my purpose. S 1600. Also, four Axiom printers, Model EX80IP (parallel). Trouble-free printers in ortginal boxes. My project canceled. S425 each or all four for S 1 600. J Turner, 309 Mac- Corkle Ave, St Albans WV 25177, (304) 776-3675. FOR SALE: Decitek paper-tape reader. Easily runs at 600 cps. 7-inch rack mount. Complete power supply, parallel inter- face, and documentation. S200 or best offer. Tom Lock, 375 Front St, Box B- 1 2. Berea OH 440 1 7, (2 1 6) 234-2798. FOR SALE: Godbout Interfacerl 2S; S200, CSI Qume Sprint 3 interfacer with 16 K buffer; S450, Jade Big Z Z80 processor card; SI 50, Pnntrol Qume Sprint 3 interface card; S75, Spell- binder word-processing program; S300. All items in excellent condition with manuals. Kirby Nickell. 2844 Angelique. St Joseph MO 64501. FOR SALE: BYTE from January 1 977 thru August 1 977 and March 1981. S21. best offer, or trade for the following BYTEs: September 1975 thru October 1976, February 1980. September 1980, October 1980. or January 1981. Mark D Ybarra, 2604 Bobolink Dr, San Jose CA 95125. (408) 264-7789, WANTED: Cartridges for Video Brain computer. Also need instructions for Finance cartridge. Particularly interested in Wordwise 2 cartridge and any schematic information. James Kasperski, 23-01 30 Dr, Long Island City NY I 1 102. FOR SALE: Zenith/Heath H-l I system. 64 K programmable memory, two 8-inch floppy-disk drives, HT-1 I, and Pascal soft- ware. Fully DEC PDP-1 1/03 compatible. S4200. K W Scholz. 8216 Pickering St. Philadelphia PA 19150. (215) 248-0439 evenings. FOR SALE: Heath H-8 computer. Assembled and tested, with manual. Will sell for best offer. David Wong, 1916 Grand Cone. New York NY 10457, (212) 294-8087. FOR SALE: TI-810 printer with full ASCII uppercase and lowercase, floor stand, paper catch, and ribbons. SI 100. HP- 232IP interactive video terminal with built-in printer. S2100. Both items purchased for a remote station, but never used and are in brand-new condition. James Leonard. 58 Beverly Dr, Columbiana OH 44408, (2 1 6) 482-229 1 . FOR SALE: IMSAI PCS 80/30 with 48 K, dual smgle/double- density diskette drives (J megabyte total), InteHigent keyboard [IKB-1J, Leedex VT-100 monitor, and /MDOS. S4000 or best offer. Bill Levering, 26 Maple Rd, Westford MA 01886. (617) 692-3847. FOR SALE: Apple II plus 64 K Pascal-language system, Zenith 13-inch color monitor, IDS-440 printer with graphics op- tion, Hayes modem, dual disk drives. Mountain Clock. Con- troller, Cashier, Apple Writer, Apple Post. VisiCalc 1.37. Dow Jones Stock Evaluator, personal programs, and other ac- cessories. S5900 complete. Fritz E Hockman, 45 Grampian Blvd, Williamsport PA 17701, |7I7J 326-4954 or 368-863 I. FOR SALE: Rockwell AIM-65 with 4 K programmable mem- ory, ROM-based text editor/assembler, 8 K BASIC m ROM, power supply, and manuals. S475. Greg Vatt, 7170 S Lewis Way, Littleton CO 80127. [303) 979-1998. FOR SALE: Terak 8510/a graphics computer system in perfect working condition. Includes DEC LSI- 1 1 processor, 56 K programmable memory, 8-inch floppy drive. 240 by 320 black- and-white graphics on 12-mch video display, full ASCII key- board, and UCSD Pascal software, including volumes 3 thru 5 of the USUS library. Excellent for schools, industry, or fanatic hobbyists. (Similar systems originally spawned UCSD Pascal.) Cost S8285 new; make offer. Jerome Wood, 6105 Harris, Raytown MO 64133, (816) 356-8290 after 5 PM weekdays. WANTED: 16 K or 32 K Exidy Sorcerer/Sorcerer II computer. I am primarily interested in the computer itself, but will consider systems with peripherals (cassette or disk, printer, video moni- tor, etc). Please state asking price in first letter— will pay any reasonable price, depending on condition and age. Christopher Lett, 145 Meadow Ln. New Rochelle NY 10805. FOR SALE: Set of 8 K Microsoft BASIC ROMs for Netronics Explorer-85 computer, All documentation included; S60. Wameco MEM-1A 8 K S-100 bus static memory with 300 ns low-power programmable memories; S75. Pat Taylor, 1200 S Market St, Bloomsburg PA 17815, (717) 784-6173. FOR SALE: PET/CBM 2001 with 16 K programmable mem- ory plus Skyles Toolkit read-only memory to debug BASIC pro- grams. About one year old. S650 FOB. Many PET programs in- cluded. Also, Divert-A-Matic phone-call diverter. SASE for description. S 1 50. Consider exchange for tape answerer. P Young, 1496 Cherrywood Dr, San Mateo CA 94403, (415) 574-4212 or 349-4325. FOR SALE: SIM-1 microcomputer with 1 K programmable memory, expandable to 4 K and 51 I/O lines. SI35. Mike Underwood, Rte 3 Box A-594, Troutville VA 24175, (703| 977-4337. FOR SALE: 32 K Exidy Sorcerer. BASIC and Assembler ROMPACs plus Extended Cassette BASIC. RS-232, parallel, dual- cassette control. All documentation plus internal hardware and software manuals. Over S450 worth of software (graphics, games, word processing, data base, utilities, etc\. All in excellent condition for SI 250 or best offer. With Comprint printer, add S500. With 1 2-inch monitor, add S75. R L Henne, 5870 Wood Flower, Burke VA 22015. (703) 250-5323. FOR SALE: IMSAI 8080 microcomputer with 48 K memory. Processor Technology boards included are: 3P + S I/O, CUTS cassette, GPM. VDM-I. and ALS-8 chip set (4 chips). Cromem- co boards included are: TV Dazzler. ZPU processor, and 8 K Bytesaver. Miscellaneous boards are: TB- 1 Extender, IMSAI MIO interface, and others. Comes with Infoton Vistar GTX video dis- play. Software includes: 15 K Extended BASIC, Music System, games, etc. All manuals included. Over S5200 invested, first offer over S3300 takes everything. Steve Dover, 821 Laramie, Wilmette IL 60091. [312) 251-4683 evenings. FOR SALE: Pro-Log Z80 single-board computer. Model 7803. for the standard bus. This board is brand new— never been out of its protective package. S 150 or trade for sailboat. Wayne Miller, 83 Brookwood Ct, Elgin IL 60120. FOR SALE: Pascal Microengme computer manufactured by Western Digital Corp. The system is fully boxed and factory tested. This is not just a board; it is virtually unused. You get 64 K programmable memory and a processor that is optimized for the use of Pascal. Asking S3000. but will take the best offer Robert Powers. 75 W Green St. Pasadena CA 91 105, (213) 792-0893. FOR SALE: Two complete SwTPC computers. Each has 24 K, MPS, MPC, MPL. JPC fast cassette, two tape decks, CT-64. 9-inch Sanyo, Fast BASIC with files, much software, and all cables. Ready to use. S800 each or S I 500 for both, including PR-40 printer. Will trade for two CT-82 terminals. Howard Johnson, [207) 244-7444. FOR SALE: Litton 1241-1251 with Multiplexer General Ledger, Payroll, Amortization, Depreciation Software, supplies, etc. Best offer. Alan Phelps, 1664 McDade Est, Conroe TX 77304, (713) 756-8889. WANTED: The United States Yacht Racing Union is developing a Race Management Manual for use by race commit- tees. A section will be devoted to computer and calculator pro- grams. We are seeking programs related to sailing, race scoring, handicapping, measurement rules, etc. A library of these pro- grams is being maintained. A listing of the programs available will be included in the manual. United States Yacht Racing Union. POB 209. Newport Rl 02840. FOR SALE: Heath/Zenith disk software for H-l 7 disk sys- tem. I changed toCP/M, and have the latest HDOS 2,0 with Ex- tended BASIC, editor, assembler, debugger, etc. With all manuals and binder, never run. Also, Microsoft BASIC for Heath H-8 or H-89 under HDOS. Latest version supports assem- bly-language subroutines. Never used. Either or both for half current catalog price. G Hammond, (603) 366-4012 evenings. FOR SALE: Tano Outpost II 6800 computer. 48 K, two RS-232 I/O ports, two 5-mch Shugart disk drives, Tano BASIC, COPS II [utility programs), Hemingway editor, compiler, and link editor. Also, Flex II ROM, Flex li, editor, compiler, and debugger. Several disks and all manuals. S2000 or best offer. Arthur Shore, (415) 364-5006. UNCLASSIFIED POLICY: Readers who are soliciting or giving advice, or who have equipment 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: 16 K Commodore PET computer, including ex- ternal cassette drive. Programmer's Toolkit ROM, Soundware's Soundbox, and assorted programs. Game programs include Microchess 2.0, Super Startrek. Tanks, Othello, Backgammon, Breakout, and Bowling. Math programs include Infinite Long Division, Synthetic Division of Polynomials, and a polar-graph plotting routine. S900. Mike Soma, 1 18 Georgetown PI, McKeesport PA 15135, [412) 751-8075. FOR SALE: SD Systems boards: SBC-200 Z80 processor; S280, VDB-8024 video controller; S300. Expandoram II 64 K; S250. All assembled and tested at factory, never used. 6 months old. Also, California Computer Systems mainframe. 12-slot motherboard, and power supply; S290. Xerox word- processing keyboard; S30. 10% off purchase of entire group. John A Maurer. (3 1 3) 884-047 1 . FOR SALE: Recently purchased HP-4IC system, including HP-4IC calculator, two memory modules, printer with six rolls of paper, card reader with two packs of cards, rechargeable battery pack, and all manuals, S600. Paul Demes. POB 279, Marshalltown IA 50158. (515) 754-2177 work, 753-3661 home. FOR SALE: Anderson Jacobson 242A acoustfc coupler. Used, but in good condition. Best offer. Greg McDonald. 1434 Fenwick Ln, Silver Spring MD 20910, (301 J 587-8536. 494 September 1981 © BYTE Publications Inc Reader Service Inquiry No. Page No. 1 47th STREET PHOTO 123 2 A B DIGITAL DESIGN 103 4 AB COMPUTERS 451 5 ABM PRODUCTS 190 6 ACKERMAN DIGITAL SYS 389 • ACTION COMPUTER 85 7 ADAPTIVE DATA & ENERGY 183 B ADV.COMP.PROD. 482, 483 9 ADV.MICRO SYS. 126 10 ADVANCED TECH 460 398 ADVENTURE INT'L 125 11 AFTERTHOUGHT ENG. 382 12 ALLENBACH IND. 158 13 ALPHA BYTE STORAGE 31 14 ALPHA BYTE STORAGE 120, 121 15 ALSPA COMP.SYS. 458 16 ALTOS COMP.SYS. 152, 153 18 AMER.COMP.&TELECOMM.265 19 AMER.COMP.EXCH. 458 17 AMER.SMALL BUSN.COMP 453 20 AMER.SQUARE COMP. 261 21 ANADEX 145 22 ANCRONA 228 23 ANDERSON JACOBSON 377 24 APPARAT INC 77 25 APPLE COMPUTER INC 12, 13 3 APPLE COMPUTER INC 12, 13 • APPLE COMPUTER INC 346 26 APPLIED SYSTEMS 422 27 ARTEC ELECTRONICS 88 28 ARTIFICIAL INT'L.RESRCH 462 29 ASAP COMP.PROD.INC. 335 30 ASAP COMP.PROD.INC. 236, 237 31 ASHTON-TATE 282, 283 32 AUTOCONTROLINC452 33 AUTOCONTROL INC 452 34 AUTOMATED EQPTMNT. 357 • AVOCET14 35 B & B ELECTR. 456 36 BASF SYSTEMS 279 37 SEAMAN PORTER 269 38 BELL.JOHN ENGR. 449 • BETA COM P.DEVICES 275 39 BISON PRODUCTS 461 40 BIT BUCKET, THE 462 41 BIZCOMP253 43 BOWER-STEWART 460 44 BUSINESS OPERTING SYS 167 45 BUSINESS WEEK 341 ' BYTE BOOKS 249 46 BYTE BOOKS 250 47 BYTE BOOKS 251 48 BYTE BOOKS 252 • BYTE BACK ISSUES 379 ' BYTE WATS 377 50 CALIF DATA CORP 462 51 CALIF. DIGITAL 484, 485 52 CALIF.COMP.SYS. 21 53 CALIF.COMP.SYS. 20 54 CAMEO ELECTR.INC 233 55 CDR SYS.INC 452 137 CHATSWORTH DATA CORP 125 58 CHECK-MATE 458 59 CHECKS-TO-GO 10 60 CHIPS & DALE 454 61 CHRISLIN INDUSTRIES 323 401 CINEMATRONICS 496 62 CLEV.CONS.COMP.& COMP- NTS. 467 63 CMC,INT'L220 65 COMPONENTS EXPRESS 369 66 COMPSTAT CO. 431 67 COMPUMART184, 185 151 COMPUPRO/GODBOUT 243 152 COMPUPRO/GODBOUT 244, 245 68 COMPUSERVE 291 70 COMPUTER AGE 322 71 COMPUTER AID 452 72 COMPUTER AID 452 73 COMPUTER DISC.OF AM. 270 74 COMPUTER EXCHANGE 321 75 COMPUTER FURN.& ACCSS. 30 76 COMPUTER MAIL ORDER 247 77 COMPUTER PLUS 456 78 COMPUTER SHOPPER 460 79 COMP. SPCLTIES. 100, 101 80 COMPUTER STOP, THE 465 81 COMPUTER STORE, THE 410 • COMPUTER WRHSE. 117 83 COMPUTERS ETC. 368 84 COMPUTERS ETC. 370 Inquiry No. Page No. 85 COMPUTERS ETC. 380 56 COMP.PERIPH.UNLTD379 86 COMPUTERS WHOLESALE 390 87 COMPUTEX CORP 294 88 COMPUTIQUE 285 89 COMPUVIEW PROD. INC. 69 90 CONCOMP IND. 308 91 CONCOMP IND. 357 92 CONCORD COMP.PROD. 468 93 CONSUMER COMP. 139 94 CONSUMER COMP. 476, 477 95 CPI 298 96 CPU SHOP, THE 459 97 CROMEMCO 1. 2 98 CS 458 * CYBERNETICS INC 359 99 D & W DIGITAL 26 * DATA DISCOUNT CTR 130 * DATA GENERAL 70, 71 101 DATA HARDWARE 460 102 DATA-ED 161 103 DATALEX COMPANY, THE 318 104 DATASOUTH COMP CORP 67 105 DATASOUTH COMP.CORP. 278 106 DATATRONIC 287 395 DELTA PRODUCTS 438, 439 107 DENVER SFTW.CO., THE 151 108 DESIGNER SOFTWARE 81 109 DIGIAC CORP 351 110 DIGIBYTE SYS CORP 205 111 DIGICOMP RESRCH CORP 160 112 DIGITAL ELECT.SYS 407 113 DIGITAL GRAPHIC SYS 371 114 DIGITAL MARKETING 355 115 DIGITAL MARKETING 6 116 DIGITAL PRESS 157 117 DIGITAL RESEARCH 127 118 DIGITAL RESEARCH COMP 488, 489 119 DIP INC. 353 120 DISCOUNT SFTW GRP, THE 374 ' DISK SUPPLY 363 121 DMA 166 122 DMA 415 123 DUAL SYS.CONTROL CORP 76 124 DUAL SYS.CONTROL CORP 78 125 DUAL SYS.CONTROL CORP 80 126 DUGGER'S GROWING SYS 458 127 DYMARC IND. 365 128 DYNABYTE BUSN.COMP. Clll 129 DYNACOMP 324, 325 130 DYSAN CORP 136, 137 131 ECOSOFT 349 132 ELECTROLABS 468 134 ELECTRONIC CONTROL 316 135 ELECTRONIC SPCLISTS 347 136 ELECTRONIC SYS.FURN 102 57 ELECTRONICS CENTER 125 138 ELLIS COMPUTING 349 139 EMPIRICAL RESRCH GRP. 456 140 EMPIRICAL RESRCH GRP. 464 141 EPSON AMERICA 299 * ESCON 373 142 EXPOTEK 393 * F.E.C.LTD. 464 * FAIRCOM417 143 FORETHOUGHT PRODUCTS 349 144 FREDERICK COMP.PROD. 367 145 FSS 460 146 FYI INC. 456 147 GIDDINGS & LEWIS 191 148 GIMIXINC362 149 GIMIXINC460 150 GNT AUTOMATIC INC 242 154 H & E COMPUTRONICS 227 155 H & E COMPUTRONICS 229 156 HANLEY ENGNRING 457 157 HAYES MICROCOMP.PROD. 63 158 HAYES MICROCOMP.PROD. 215 * HEATH COMPANY 16, 17, 207 * HEATH POSTCARD 400 A&B 159 HEMENWAY ASSOC. 319 160 HEWLETT-PACKARD 51 161 HOBBY ROBOTICS 454 162 HOUSTON INSTRUMENTS 224 163 HOUSTON INSTRUMENTS 224 164 IMS INTERNATIONAL 159 * INDEPENDENT BUS.SYS. 119 166 INFOSOFT SYSTEMS INC 286 167 INNOVATIVE PROD. 364 168 INNOVATIVE SFTW APPL 176 169 INT'LMICROSYS311 Inquiry No. Page No. 171 INTEGRAND 345 172 INTEGRATED BUSN.COMP. 425 173 INTERACTIVE MICROWRE 210 * INTERACTIVE STRUCT. 328 174 INTERACTIVE STRUCT. 338 193 INTERTEC DATA 25 175 INTERTEC DATA SYS. 177 176 IPEX INT'L 458 177 ITHACA INTERSYSTEMS 8, 9 178 JADE COMP.PROD 471 179 JADE COMP.PROD. 472, 473 180 JAMECO ELECTR. 486, 487 181 JDR MICRODEVICES 474, 475 182 JMCA SOFTWARE 454 183 KADAK PRODUCTS 300 * KENGORE CORP. 454 184 KERN PUBLISHING 351 185 KLO-FOX 460 186 KV 33 462 1B7 LABORATORY MICROSYS. 377 188 LADCO DEVELMNT CO INC 380 189 LIFEBOAT ASSOC 263 190 LIFEBOAT ASSOC 309 191 LIFEBOAT ASSOC 213 192 LNW RESEARCH 331 194 LOGO COMP.SYS. 343 195 LOMAS DATA PRODUCTS 367 196 LYBEN COMP.SYS. 452 197 MACROTRONICS 452 198 MACROTRONICS 462 199 MAGNOLIA MICROSYS 454 200 MALIBU ELECTR CORP 143 201 MANNESMANN TALLY 413 202 MAROTSFTW.SYS.INC203 203 MARTEC 369 204 MARYMAC INDUSTRIES 373 205 MASTER ELECTR.INC 96 206 MAURO ENGINEERING 268 207 MAXTEK 32 400 MCCLINTOCK CORP 158 * MCGRAW-HILL BOOK CO 256, 257 208 MCGRAW-HILL BOOK CO 350 * MCMILLAN BOOK CLUBS 305 209 MEADE'S DATA SYS 454 210 MEAS.SYS. & CONTROLS 28, 29 211 MEMORY MERCHANT 53 212 MENTOR SOFTWARE 460 213 META TECHNOLOGIES 440 214 MICRO AGE COMP.STORE 174, 175 216 MICRO BUSINESS WORLD 179 217 MICRO BUSN. ASSOC 458 399 MICRO BUSN. SYS 125 218 MICRO COM 147 220 MICRO DECISIONWARE 140 221 MICRO FOCUS 79 222 MICRO HOUSE 280, 281 ' MICRO 310 223 MICRO MANAGEMENT SYS 347 348 MICRO MINT 383 224 MICRO PRO INT'L 231 225 MICRO SCI 93 226 MICRO SOURCE OF TX 466 227 MICRO WORKS, THE 365 228 MICROACE 369 229 MICROCOMP.TECH.INC173 230 MICROCOMPUTER APP. 387 231 MICROCRAFT SYS 214 232 MICRODASYS 201 234 MICROMAIL376 235 MICROMATE ELECTR.INC 345 236 MICROSOFT (CPD) 111 237 MICROTECH EXPORTS 212 238 MIKOS 466 239 MILLER MICROCOMP.SERV 288 240 MINI COMP.SUPPLIERS 357 241 MINI MICRO MART 478 242 MINI MICRO MART 479 243 MINI MICRO MART 18 244 MIRO COMPUTERS INC 375 245 MORROW DESIGNS 57 246 MOUNTAIN COMPUTER 19 247 MOUNTAIN VIEW PRESS 195 248 MPI 181 ' MRD SYS INC 464 249 MSD 156 250 MTI188 251 NASHUA CORP 162 252 NAT'L DATA SUPPLIES 462 ' NATIONAL COMP. SHOW 339 253 NEBS 208 254 NEEC0 295 To get further information on the products advertising 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 an 1 8-cent stamp to the card, then drop it in the mail. Not only do you gain information, but our advertisers are encouraged to use the marketplace provided by BYTE. This helps us bring you a big- ger BYTE. The index is provided as an additional service by the publisher, who assumes no liability for errors or omissions. "Correspond directly with company. Inquiry No. Page No. • NETRONICS104, 106, 348 255 NORSEA DATA CORP 165 256 NORTH AMER TECH 178 257 NORTH AMER TECH 82 258 NORTHWEST COMPUTER 361 259 NOVATION 290 • NRI SCHOOLS ELECTR DIV 289 • OASIS SYSTEMS 258 260 OHIO SCIENTIFIC INSTR C IV 261 OKIDATA CORP 219 389 OKIDATA CORP 221 262 OLIVER ADVANCED ENGIN 464 263 OLYMPIC SALES 363 264 OMEGA MICRO COMPUTER 421 265 OMEGA SALES 302, 303 266 OMIKRON 49 267 OMNI RESOURCES 115 133 ORACLE ELECTR 456 268 ORANGE MICRO 148, 149 269 ORANGE MICRO 141 271 ORION INSTRUMENTS 464 272 OSBORNE COMPUTERS 33 273 OSBORNE WILSON LABS 332 274 OSBORNE/MCGRAW-HILL 107 ' OWENS ASSOC 254, 255 275 PACIFIC COMP BRK 226 276 PACIFIC DISC SFTW 462 277 PACIFIC EXCHANGES 382 278 PACIFIC EXCHANGES 454 279 PACIFIC EXCHANGES 464 280 PACIFIC EXCHANGES 416 396 PACIFIC MEDIA PRODUCTS 194 281 PAGE DIGITAL 480, 481 282 PALOMAR COMP EQUIP 333 283 PAN AMERICAN ELEC INC 470 284 PAPER TRACTOR 379 285 PASSWORD DISTR 431 286 PC NEWSLETTER 382 287 PEACHTREE SOFTWARE 73 ' PERCOM DATA 7, 15 288 PERCOM DATA 454 291 PERSONAL COMPUTERS 272 • PETRO-LEWIS CORP 234 292 PHASE ONE SYS INC 267 293 PICKLES & TROUT 366 294 POLY PAKS 458 295 POLYLINE CORP 464 • POPULAR COMPUTING 225 296 POTOMAC MICRO-MAGIC 411 297 POWER ONE INC 163 298 PRACTICAL MGMNT SYS 462 299 PRIORITY ONE 490, 491 300 PRIORITY ONE 492, 493 301 PROTECTO ENTERPR 456 302 PURCHASING AGENT, THE 186 303 QANTEX DIV 327 304 QUALITY COMP PARTS 464 305 QUALITY COMP PARTS 84 306 QUALITY SOFTWARE 91 307 QUASAR DATA PROD INC 313 308 QUEST ELECTR 455 309 R KS ENTERPRISES INC 312 310 R.R.SOFTWARE 371 311 RACET COMPUTES 361 312 RADIO SHACK 35 313 RADIO SHACK ASSOC STR 124 314 RADIO SHACK-GLNW SPR 347 315 RADIX INC 456 316 ROBOTICS AGE 361 317 S C DIGITAL 373 318 S-100 INC 365 319 SCIENTIFIC ENGRG LABS 206 320 SCIENTIFIC SFTW PROD 458 321 SCION CORP 5 322 SCITRONICS 412 • SCOTTSDALE SYSTEMS 154 324 SCR ELECTR 464 325 SEATTLE COMP PRODS 113 326 SECURED COMP SYS 462 327 SELECT INFO SYS 293 328 SIERRA DATA SCIENCES 370 329 SLUDER 456 330 SOFTECH MICROSYS 317 • SOFTWARE ARTS 273 233 SOFTWAREHOWS 65 • SOLID STATE SALES 172 332 SORRENTO VALLEY ASSOC 340 333 SOUTHERN COMP SYS 456 334 SOUTHWEST TECH PROD C II 335 SPECIALIZED BUSN SYS 375 336 SPECTRUM SOFTWARE 197 337 SSM MICRO COMP PROD 1 1 • STATCOM CORP 89 338 STATIC MEMORY SYS 235 339 SUBLOGIC 315 340 SUNNY INT'L 470 341 SUPER STAR INT'L 222 • SUPERSOFT 54, 99, 155, 358, 378, 381 342 SURVEYOR SUPPLY CO 367 343 SYBEX 93 • SYNCHRO SOUND 334 344 SYNCTRONICS 170 397 SYNEMED, INC 109 345 SYS INTERFACE CONSUL 92 September 1981 © BYTE Publications Inc 495 Inquiry No. Page No. Inquiry No. Page No. Inquiry No. Page No. Inq jiry No. Page No. 346 SYSTEMS PLUS 189 357 THREE M COMPANY 223 368 U.S. MICRO SALES 307 • VR DATA 363 • TAB BOOKS 337 358 THREE M COMPANY 94 369 U.S. MICRO SALES 463 381 WASHINGTON COMP SERV 469 347 TARBELL ELECTR 351 359 THREE M COMPANY 95 370 U.S. ROBOTICS 271 382 WEIGH SYSTEMS TECH 292 * THUNDERWARE 187 371 UNIVERSAL SFTW.STUDIOS 418 • WESTICO INC 171, 452 349 TEAM ELECTR 371 ■ TINNEY.RBT.GRAPHICS 408 372 UVEON COMP SYS 27 383 WESTWARE 129 • TECHNICAL SYS CONS 199 360 TKS CORP 329 373 VAN HORN OFFICE SUPP 375 * WHITESMITHS LTD 131 350 TECMAR INC 301 361 TNW CORP 367 374 VAN DATA 409 384 WICAT SYSTEMS 55 351 TEI, INC 61 362 TOSHIBA AMERICA INC 23 375 VECTOR ELECTR 86 385 WICAT SYSTEMS 217 352 TEI, INC 239 363 TRANSFORMATION TECH 454 376 VECTOR GRAPHICS 75 49 WILLIAMS LABS 368 353 TELERAM COMMUNC 306 364 TRANSNET CORP 345 377 VERBATIM CORP 87 386 WINTEK CORP 452 354 TELEVIDEO INC 209 365 TRANSWAVE CORP 193 378 VERTICAL DATA SYS INC 150 387 WINTERHALTER & ASSOC 326 355 TERCER MEDIO 211 366 TRINITY GRP, THE 460 390 VI D EX 277 388 X COMP 297 356 TEXAS COMP SYS 204 379 VISTA COMPUTER CO 105 " ZOBEX 83 ' TEXAS INSTRUMENTS 135 367 TSE/HARDSIDE 366 380 VOTRAX 168, 169 BOMB )naoina Monitor Box BYTE' sC Article # Page Article Author(s) 1 38 Build an Unlimited-Vocabulary Speech Synthesizer Ciarcia 2 52 The Big Board: A Z80 System in Kit Form Thompson 3 58 The Xerox Alto Computer Wadlow 4 72 Tree Searching, Part 1 : Basic Tech- niques Williams 5 112 One Step Forward— Three Steps Backup Stakem 6 146 Misosys Software's DISKMOD: Put Radio Shack's Editor/Assembler on Disk Hughes 7 150 MINCE, A Text Editor Kern 8 164 Artificial Intelligence Roberts 9 180 A High-Level Language Benchmark Gilbreath 10 200 , Science Fiction's Intelligent Computers Byrd 11 216 Symbolic Differentiation a la LISP Nicol 12 238 Knowledge-Based Expert Systems Come of Age Duda, Gaschnig 13 284 The Atari Tutorial, Part 1 : The Display List Crawford 14 304 Natural-Language Processing, The Field in Perspective Hendrix, Sacerdoti 15 384 BYTE's Arcade: Big Five Software; The Prisoner Williams, Liddil 16 368 Three Microcomputer LISPs Levitan, Bonar 17 414 The Emperor's Old Clothes Hoare 18 436 Interactive Fiction: Six Micro Stories Liddil June BOMB Speaks Out Steve Ciarcia's "Build a Low- Cost Speech-Synthesizer Interface" has talked its way into first place this month. Steve gets the SI 00 purse for his description of National Semiconductor's Digitalker speech- synthesis system. The article, ob- viously, left our readers speechless. The $50 second-place award goes to Gary Kildall for his article, "CP/M: A Family of 8- and 16-Bit Operating Systems," which describes the de facto standard "software bus." Robert Greenberg and James Larson tied for third place. Greenberg's "The UNIX Operating System and the XENIX Standard Operating Environment" provided an inside look at a large- computer operating system for microprocessors. Larson's article, "The Ins and Outs of CP/M," clarified and expanded on in- put/output and disk interfacing within the CP/M environment. GAME DESIGNERS CINEMATRONICS, a leader in the coin-operated video game industry, is expanding its game design staff. We are seeking individuals with the special talent for game design, exceptional creativity, and superior Assembly language programming skills. CINEMATRONICS offers competitive salaries, paid sick and vacation time, medical coverage, pension and profit sharing. If you're looking for an excellent opportunity with a rapidly growing, employee conscious company, please forward your resume to Sandra Baca, Director of Personnel: CINEMATRONICS, INC. 1841 Friendship Drive, El Cajon, CA 92020 An Equal Opportunity Employer 496 September 1981 © BYTE Publications Inc Circle 401 on inquiry card. The Dynabyte Difference: Unequalled price/performance with total expandability. Buy ing the powerful Dynabyte 5615 isn't only smart, it's cost efficient. The 5615 is the sure way to get the system you need. With more power for the price. You can select memory to 400 KB on our S-100 bus architecture. Choose from 3 sizes of Winchesters to 45 MB and have diskette back- up to your system also. If it's tape back-up you need, then choose our 5700. If you need less storage, our 5 l A" floppy 5200, our 8" floppy 5300 or our 5400 system using both floppies, with up to 3.6 MB capacity, can be yours. The 5615 system is available with either single user CP/M or our enhanced MP/M for multi-user applications. Our MP/M operating system supports up to eight terminals, with a separate or shared spooler, and up to sixteen printers with no required partition space. Add to this multi-tasking, bank switching, record lockout, type-ahead and DMA and you have an MP/M operating system that supports a host of existing languages and meets minicomputer standards. No multi-user applications library is so responsive to your needs. The 5615 features Business Manager,™ the fully integrated, menu-driven, well documented, easy to install accounting system that gives you file/record protection, HELP commands, multi-level security, keyed data access, internal disk management, available source code and more. System expandability, power and price/performance are further enhanced by on-hand avail- ability, quantity discounts, 180-day warranty and a national WATS line for support. Whether you use or sell computer systems, you should ask about the microcomputer that puts minicomputer capability in your hands. That's the 5615. That's the Dynabyte Difference. Call Mike Seashols,V P Marketing (800) 227-8300. In California (415) 329-8021. Dynabyte, 115 Independence Drive, Menlo Park, I BuSineSS Computers California 94025. Business Manager is a registered trademark of Dynabyte. CP/M and MP/M are registered trademarks of Digital Research Corp. Circle 128 on inquiry card. "Over 15,000 items in inventory could be a nightmare. But it's not 'cause my Challenger g*%± computer works like a I^J dreamt "My fastener business is growing rapidly. I have over 800 customers utilizing my 15,000 inventory items daily. Keeping track of inventory, orders, and receivables at this volume level could be a nightmare. But it's not 'cause my Challenger com puter works like a dream. Terrific, Ohio Scientific!" Richard Nolan, President, Aerospace Nylok Corp., Hawthorne, New Jersey Ohio Scientific was first to add Winchester hard disk drives to microcomputers. This advanced technology allows low cost microcomputers to store over 100 times as much information on line as they could before. "With our Challenger computer we've developed sophisticated real estate programs and information files that give our customers and our sales associates that extra edge in fast, accurate real estate market information analysis and forecasting. We now have a strong managerial accounting and market information system as well as word process- ing at an affordable cost. Terrific, Ohio Scientific!" Charles Smith, Jr., President, Montague, Miller & Co., Realtor Charlottesville, Virginia OHIO SCIENTIFIC HARD DISK BASED MICROCOMPUTERS START AT LESS THAN $10,000 AND ARE SOLD BY MORE THAN 400 DEALERS NATIONWIDE. FOR THE ONE NEAREST YOU, CALL 1-800-321-6850 TOLL FREE. i x. I "I'm a fuel oil jobber, and I can't believe how reliable my Challenger has been, with all it has to keep track of. But, it's been doing it for two years now, and that's terrific, Ohio Scientific!" Wade Carlson, Vice President, Wally Carlson & Sons, Lindstrom, Minnesota [//" \J 1333 SOI a vljJI&eDtl Company 333 SOUTH CHILLICOTHE ROAD AURORA, OH 44202 • [21 6] 831 -5600 Circle 260 on inquiry card.