SEPTEMBER 1980 Volume! $2.50 in USA/$2.95 in Canada ttie small systems journal -A MCGRAW-HILL PUBU;CATIO#- i^: HONEBREWING OFTEN FIRST - ALWAYS THE BEST When we introduced the "S" system last year we knew that we were ahead of the industry. We didn't realize just how far. WE KNEW THE NEEDS- When we began designing the S/09 computer, we knew that the normal eight-bit microprocessor sys- tem was not adequate for any but the smallest, single user business applications. What was worse there was little that could be done to expand the capabilities of the system if the customer needed it. There is nothing much worse to a business customer than a "dead end" system. MEMORY ISTHE KEY- Obviously a business system should be able to operate with multiple terminals if needed. It should also be able to do a variety of jobs; not just data processing, but also word processing and com- puter aided instruction. With a system limited to 64K bytes of memory addresses such a system is just not practical. The amount of user memory available to each terminal is too small for useful work. HOW DO YOU GET IT- The common solution to this problem is called bank switching. This process is similar to a selector switch that turns on the bank of memory that you want to work with. This, however, has a few pro- blems. It is inefficient, therefore expensive, plus being slow. It is also extremely clumsy when data must be exchanged between two different pro- grams. Besides with all this you still cannot use more than 64K of memory for any one program. So what is the alternative? DO IT RIGHT- The alternative is an address bus with more than the normal 16 bits found on eight-bit microproces- sors. By using 20 address bits you can, for instance, address up to a million memory locations directly. This way you have access to any part of memory at any time without any intermediate processes. Pro- gram interaction is now no problem at all. SOFTWARE MUST MATCH- So far we have a computer system with a large memory capacity and the ability to operate with many terminals, but this is not enough. You need an operating system just as sophisticated as the hardware to complete the job. It must be a multi- tasking (therefore multiuser) operating system and it must be fast if it is to be useful with multiter- minal systems. UniFLEX® fills these requirements and more. It also has multiple directories, log-in and password features. UniFLEX® was patterned after UNIX"'"'^,which is one of the most highly re- garded operating systems around. PERIPHERALS TOO- To complete the system we offer our smart ter- minals, and a variety of disk systems. We have everthing from a 390K byte floppy to a 40 Meg/ byte Winchester drive. All peripherals are compa- tible and so you can start with a small single terminal system and upgrade if necessary to a fully expanded system— 1 6 terminals, 768 bytes of RAM memory and 96 Meg/bytes of disk storage. GET THE WHOLE STORY- If you are planning to install, or sell business systems you should get our information package on the most versatile and cost effective system on the market, the S/09. You can get a 128K system (less printer) for a little over $5,000.00. *UNIX is a Trademark of Bell Laboratories. SYSTEM SOFTWARE Languages Operating Systems Assembler FLEX* BASIC UniFLEX FORTRAN Pascal PILOT Word Processing Data Processing General Ledger Word Processing Editor Text Processor Accounts Receivable Accounts Payable Payroll Utilities Job cost Debug Package Inventory Sort-Merge Mail List Diagnostics *Supplied with over 40 ulilities SOUTHWEST TECHNICAL PRODUCTS CORPORATION 21 9 W. RHAPSODY SAN ANTONIO, TEXAS 78216 (512) 344-0241 Circle 353 on inquiry card. 1' +J 1 im irti ■ iw Hii n» 14 .'1 . m * »' ftccountt Payable Management Information Display Ultrasonic heart sector scan High-resolution display with alphanumerics Get the professional color display that has BASIC/FORTRAN simplicity LOW-PRICED, TOO Here's a color display that has everything: professional-level resolution, enormous color range, easy software, NTSC conformance, and low price. Basically, this new Cromemco Model SDI* is a two-board interface that plugs into any Cromemco computer. The SDI then maps computer display memory content onto a convenient color monitor to give high-quality, high- resolution displays (756 H x 482 V pixels). When we say the SDI results in a high- quality professional display, we mean you can't get higher resolution than this system offers in an NTSC-conforming display. The resolution surpasses that ola 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-megabyte 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 SD! 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. Circle 1 on inquiry card. Q Cromemco Incorporated 280 BERNARDO AVE., MOUNTAIN VIEW, CA 94040 • (415)964-7400 Tomorrow's computers today byte September i98o Here's the state of the art in low-cost hard-disk computers 11 MEGABYTES OF FAST HARD-DISK STORAGE Yes, the Cromemco Model Z-2H is in a class by itself in the computer field. These Z-2H features tell you why: • 11 megabytes of hard-disk storage • 64 kilobytes of fast RAM • Two dual-sided floppy disk drives • Z-80A type processor • Fast 4 MHz operation — 150 nanosecond access time • Fast hard-disk transfer rate of 5.6 megabits/second Low cost that's not all you get. Not And nearly. BROAD SOFTWARE SUPPORT You also get Cromemco software support — the broadest software sup- port in the microcomputer field. Soft- ware that Cromemco is known for. Like this: • Structured BASIC • FORTRAN IV • RATFOR (RATional FORtran) • COBOL • Z-80 Macro Assembler • Word Processing System • Data Base Management And more all the time. FIELD PROVEN The Z-2H is clearly in a class by it- self. We introduced it last summer. It's field proven. It's reliable. And it's rugged. Housed in a sturdy, all-metal cabinet. EASILY EXPANDABLE As always with Cromemco, you get expandability. The fast 64K RAM in this Model Z-2H can be expanded to 512 kilobytes. That amount of RAM combined with 1 1 megabytes of hard- disk storage gives you enormous Circle 1 on inquiry card. Q computer power — the equal or even beyond what much larger computers sometimes offer. What's more, this computer gives you a 12-sIot card cage. That's to plug in your special circuits as well as additional RAM and interface cards. This expandability is supported by still more Cromemco value — the Z-2H's heavy-duty power supply that gives you 30A at 8V and 1 5A at ± 1 8V to support plug-ins. LOW COST — SEE IT NOW The Z-2H is real. It's been in the field for many months. It's proven itself. You should see the Z-2H now. Con- tact a Cromemco representative and arrange for a demo. Learn that Cro- memco is a survey-winner for reli- ability. And learn that the Z-2H is under $10K. In the long run it always pays to get the best. Cromemco incorporated 280 BERNARDO AVE., MOUNTAIN VIEW, CA 94040 Tomorrow's computers today (415)964-7400 In The Oueue BlITI September 1980^ Volume 5, Number 9 ^ Page 26 Page 46 Page 76 Page 126 Foreground 1^26 BUILD A LOW-COST, REMOTE DATA-ENTRY TERMINAL by Steve Ciarcia This terminal increases the flexibility of computer home-control systems. 46 AN 8088 PROCESSOR FOR THE S-100 BUS, Part 1 by Tom Cantrell Part 1 covers the basic design considerations of an S-100 processor board based on Intel's 8088 microprocessor. 86 PENNY PINCHER'S JOYSTICK INTERFACE by Steven Wexler For about $6 and one night's work, you can add this interface to your system. 116 APL CHARACTER GENERATOR by John W hanger Jhis is a simple modification for any video display employing the MCM6571 character generator. ^"^126 CONSTRUCTION OF A FOURTH-GENERATION VIDEO TERMINAL, Part 2 by Theron Wierenga Part 2 helps you to complete the construction of the terminal and learn to use the built-in debugging features. 242 KHACHIYAN'S ALGORITHM, Part 2: Problems with the Algorithm by G C Berresford, A M Rockett, and J C Stevenson A practical BASIC program can be used to explore the power and limitations of this new algorithm. 270 EXPLORING BALLISTICS WITH YOUR COMPUTER by Robert W Jenks This BASIC program helps the target shooter to calculate the complex path of bullets. 282 AN INTERRUPT-DRIVEN REAL-TIME CLOCK FOR THE TMS 9900 by Thomas G Morris Jr Three selectable interrupt rates make the Texas Instruments 16-bit processor count time. \^328 A BASIC FLOPPY-DISK ACCOUNTING SYSTEM by Joseph J Roehrig Here's a complete six-program package to keep your budget records in order. Ba 1^76 Packground 76 DISSECTING THE TI SPEAK & SPELL by Michael A Rigsby With these notes you can move toward the eventual goal of getting this toy to talk under personal- computer control. 102 MACHINE PROBLEM SOLVING, Part 1: Trial-and Error Search, A Mechanical Plan to Save the Missionaries by Peter W Frey Simple games help to express this method of solving problems with computers. 180 FCC REGULATION OF PERSONAL- AND HOME-COMPUTING DEVICES by Terry G Mahn New rulings by the FCC will affect the use and manufacture of personal computers. 206 VARIETIES OF THREADED CODE FOR LANGUAGE IMPLEMENTATION by Terry Ritter and Gregory Walker Some kinds of threaded code are position and system independent. 230 EDUCATION FORUM: NEW CULTURES FROM NEW TECHNOLOGIES by Seymour Papert Children should learn to compute in the same way they learn to talk. Nucleus 6 Editorial: Intellectual Ethics and Software 14 Letters 66, 322, 324 Programming Quickies 304, 308, 310 Book Reviews 94 Languages Forum 96, 194, 314, 318, 321, 326 Technical Forum 114, 312 BYTE's Bits 164 BYTELINES 172 Ask BYTE 256 Clubs and Newsletters 260 Event Queue 268, 313 BYTE's Bugs 336 What's New 398 Unclassified Ads 399 BOMB, BOMB Results 400 Reader Service September 1980 © BYTE Publications Inc 3 Publishers Virginia Londoner, Gordon R Williamson Associate Publisher John E Hayes Assistant Cheryl A Hurd Founding Editor Carl T Helmers Jr Editor-in-Chief Christopher P Morgan Editors Richard S Shuford, Gregg Williams, Curtis P Feigel, Harold Nelson Stan Miastkowski Consulting Editor Mark Dahmke Book Editor Bruce A Roberts Chief Copy Editor David William Hayward Copy Editors Faith Hanson, Warren Williamson, Robin M Moss, Anthony J Lockwood Assistant to the Editors Faith Ferry Assistants Debe Wheeler, Karen A Cilley New Products Editor Clubs, Newsletters Charles Freiberg Drafting Jon Swanson Production Director Nancy Estle Assistant Production Director Christine Dixon Production/Advertising Coordinator Wai Chiu Li Production Art Holly Carmen LaBossiere, Deborah Porter Chief Typographer Sherry McCarthy Typographers Debi Fredericks, Donna Sweeney Advertising Director Thomas Harvey Assistants Ruth M Walsh, Ms. Marion Gagnon Barbara J Greene, Janet Ames Special Projects Coordinator Jill ECallihan Marketing Coordinator Laura A Hanson Circulation Manager Gregory Spitzfaden Assistants Agnes E Perry, Melanle Bertoni, Barbara Varnum, Louise Menegus, Andrew Jackson Dealer Sales Thomas Yanni Controller Daniel Rodrigues Assistant Mary E Fluhr Accounts Receivable Specialist Karen Burgess Accounts Receivable Assistant Jeanne Cilley Receptionist Jacqueline Earnshaw Traffic Department Mark Sandagata, Rob Hannings About This Issue BYTE is Hve years old this month, and we're taking the opportunity to discuss one of our favorite subjects: homebrewing. Much of the personal computer hardware sold to- day is already assembled; even so, many of our readers like to build or modify their own equipment, and even "homebrew" it from scratch. The cover photograph by Raoul Hackel, Stock Boston, shows some colorful wiring harnesses inside a computer chassis, a familiar sight to the intrepid do-it-yourselfer. Theme articles in this issue include a build-it-yourself, low-cost, remote data-entry terminal (from Steve Ciarcia); exploring the TI Speak & Spell; a pennypincher's joystick interface; and the beginning of a multipart article on building an 8088 processor for the S-100 bus. Along with these are features on threaded code; FCC regulations and your personal computer; machine problem-solving; some tax hints for personal computer owners; and much more. You've probably noticed that this issue of BYTE is on the large side. In fact, it's the biggest issue we've ever printed. The extra space allows us to bring you even more articles and features in this issue and in the coming months. . . . CM Officers of McGraw-Hill Publications Company: Paul F. McPherson, President; Executive Vice Presidents: James E. Boddorf, Gene W. Simpson; GroupVice President: Daniel A. McMillan; Senior Vice President-Editorial: Ralph R. Schuiz; Vice Presidents: Kemp Anderson, Business Systems Development; Stephen C. Croft, Manufacturing; Robert B. Doll, Circulation; James E. Hackett, Controller; William H. Hammond, Communications; Eric B. Herr, Planning and Development; John W. Patten, Sales; Edward E. Schirmer, International. 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. BYTE is published monthly by BYTE Publications Inc, 70 Main St, Peterborough NH 03458, a wholly-owned subsidiary of McGraw-Hill, inc. Address all mall except subscriptions to above address: phone (603) 924-9281. Address subscriptions, change of address, USPS Form 3579, and fulfillment questions to BYTE Subscriptions, PC Box 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 $18 for one year, $32 for two years, and $46 for three years in the USA and its possessions. In Canada and Mexico, $20 for one year, $36 for two years, $52 for three years. $32 for one year air delivery to Europe. $32 surface delivery elsewhere. Air delivery to selected areas at additional rates upon request. Single copy price is $2.50 in the USA and its possessions, $2.95 in Canada and Mexico, $4.00 in Europe, and $4.50 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 the above address. 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 © 1980 by BYTE Publications Inc. All rights reserved. BYTE® 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 WC1R 4EJ ENGLAND. Member Subscription WATS Line: (800) 258-5485 Office hours: Mon-Thur 8:30 AM - 4:30 PM, Friday 8:30 AM - Noon, Eastern Time Audit Bureiu of Circnlitions NATIONAL ADVERTISING SALES REPRESENTATIVES: NORTHEAST (617) 444-3946 Hajar Associates 280 Hillside Ave. Needham Heights MA 02194 MIDWEST (312) 864-3467 Hajar Associates 2405 Law nd ale Evanston IL 60201 EAST & SOUTH (212) 682-5844 Hajar Associates 521 Fifth Ave. New York NY 10017 SOUTHWEST (714) 540-3554 NORTHWEST (415) 964-0706 Hajar Associates 1000 Elwell Ct, Suite 227 Palo Alto CA 94303 September 1980 © BYTE Publications Inc Circle 2 on inquiry card. MICROANGELO HIGH RESOLUTION GRAPHICS SINGLE BOARD COMPUTER by SCION CORPORATION RS-170 com- posite or direct drive output Local or external sync generation 4 or 5 Mhz Z80 micro- processor 60 hertz real- time clock 8 level interrupt tie-in IEEE SlOO bus ^ compatible Screenware^^ Pak I A 4K byte operating system resident in PROM on MicroAngelo!^ Pak I emulates an 85 char- acter 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. SCION Corporation 8455-D Tyco Road Vienna, Va. 22180 (703) 827-0888 Light pen interface Time multi- plexed refresh 4K resident Screenware™ Pak I operating system 32KRAM isolated from host address space High speed communica- tions over parallel bus ports Host Resident Terminal Software An interface software package that coordi- nates input/output from the MicroAngelo^^ graphics board, the MicroAngelo™ keyboard, and your computer. The result is a flexible, yet sophisticated graphics terminal. European Distributor: Micro Diversions UK Ltd. 17/19 Mesnes Street Wigan, England WN1 1QP 09-423 4311 Now-Break Through The 64K Micro-Memory Limit! SIXTEEN Bank Selectable 16K Static RAM SAVE $50.09 LIMITED TIME OFFER Don't buy any more antique RAMs (RAM without bank select) — now there's Netronic's new SWEET SIXTEEN board featuring a universal soft- ware bank select system. SWEET SIXTEEN is capable of addressing 2,048 different banks. With SWEET SIXTEEN boards you can add mem- ory beyond the 64K limit, or expand to a multi- terminal system. LOOK AT THESE FEATURES: • 300 MS, low power 21 14's. • Software Bank Selector — Universal decoder works with Cromenco, Alpha Micro. Neironics. most other sysiems. or your design. Onboard dip switches: Bank Select Enable; Reset Enable.- Reset Disable; Port Address; Port Data. • All Inputs And Outputs meet the proposed IEEE standards for the S-100 bus. • 4.0 MHz Operation. • Schmitt Trigger Buffer on all signals for maximum noise immunity. • Addressable On 16k Boundaries, Q-64k, dip switch selectable. • Phantom Option, dip switch selectable. • PWR/MWRITE Option, dip switch selectable. • LED Indicator to display status. • Glass Epoxy PC Board with gold-plated contacts and double-sided solder mask. • Fully Socketed. • Four Separate Regulators for maximum stability. 10-Day Money-Back Policy For Wired & Tested Unit: Try a fully wired board — then either keep it. return it for kit, or simply return it in working condi- tion. Continental U.S.A. Credit Card Buyers Outside Connecticut: CALL TOLL FREE: 800-243-7428 From Connecitcui Or For AssisiancB: (203)354-9375 Please send the items checked below: D SWEET SIXTEEN kit; No. S-16 . . . (reg. price $249.95) now $199.95* D SWEET SIXTEEN, fully assembled, tested, burned in; No. S-16W . . . (reg. price $289.95) now $239.95* *Plus $2 postage & insurance. Connecticut residents add sales tax. Total Enclosed: S D Personal Check D Money Order/Cashier's Check n VISA D Master Charge (Bank No. ) Acct. No. '. Exp. Date Signature Print Namp Address City State Zip ISiiNETRONICS RESEARCH & DEVELOPMENT. LTD. 333 Litchfield Rd , New Milford, CT 06776 Ef3itf^^8i Intellectual Ethics and Software An Inquiry Into the Nature of Ideas^ Academia, and Commerce Carl Helmers Recently, I encountered an old problem again. A problem in this sense is a body of questions and my tentative answers. An old problem is like an old jacket. You get familiar with the intricacies of its individual creases, wrinkles, and holes. It may not be currently stylish, or even in the best of conditions. Yet it is hardly worth throwing out because of a shared body of experience. So, I had long ago packed this problem away in my mental baggage. The problem I refer to is ethical in nature; it has epistemological attributes as well. It is the problem of interfacing the world of ideas with the world of com- merce. In its simplest form it is a two-part question: "who originated an idea?" and "what is the value of that idea?" The problem, which has great practical implications in our technological civilization, is that of encouraging innova- tion by means of rewards in the worlds of ideas and commerce. The ethical position implicit in my viewpoint is simple honesty. Its intellectual expression is that credit should be given where credit is due in a freely operating world of ideas. In a laissez-faire world of commerce, its expression is that value in the marketplace should be given where value is due, in a framework of freely chosen relationships. We humans have two worlds of activity: the intellectual world and the world of commerce. Each has its own characteristics. One deals with ideas and thoughts freely expressed. The other deals with material goods freely traded in the marketplace. We can engage in both of these very natural human pursuits to the extent that we are politically free of arbitrary laws and interference. What, you might ask, brings about a discussion of ethics in the marketplace at this time? The particular impetus to this discussion is an incident that came to my knowledge at a recent trade show. Inasmuch as the incident is far from closed, I will not disclose the names of the parties involved. But the situation in its abstract form is worth using to explore some of the ethical problems of commerce in ideas, particularly software for small computers. Several years ago, a small group of academics began pursuing a particular line of inquiry that related to the nature of computer design for human interac- tion. The charter of this group of researchers might have been expressed as: "Find the problems of human interaction with computers, and experiment with any solutions you may find." As in any academic pursuit, the inquiry generated many published papers over more than a decade. The fact that these papers also generated some exciting hardware and systems software entered the picture along the way. Both the software and hardware developments of this group's research have been and are generously underwritten by the sponsoring organization where the activity takes place. In fact, the sponsoring organization did not expect the research to have any immediate practical expression in the marketplace, because it was basic research. 6 September 1980 © BYTE Publications Inc Jfflcrocompv msn iTOUCH ^ 'Tor reliable data storage, I recommend systems with Shugart disk drives^ !9w Tom Knight, President— Nycom, Los Altos, California "The last thing you need when you put yourpersonal computer or small business system to work is a disk drive that you can't rely on. If the drive quits, your system is out of business!' That^ why more and more manu- facturers and dealers depend on Shugart disk drives for reliable data storage. These professionals don't want disk drive prob- lems any more than you do. Shugart has a large family of drives, too— in all sizes and capacities to suit your system storage needs. For the smaller system, the original 5y4-inch Minifloppy '" stores 250 to 500 kilobytes (single or double-sided)— that's about 50 to 100 pages of printed material. Our single and double-sided 8-inch floppys store 800 to 1600 kilobytes. And for systems that need a larger data base, our 8-inch or 14-inch fixed disk drives store from 5 to 58 megabytes. No other manufacturer offers such a wide variety of disk storage for personal computer and small business systems. Word processing, general business, accounting— big system or small, you can rely on Shugart drives. We're known as the Headstrong company for good reason. We're Headstrong about reliability, quality, and value. Ask your dealer He knows us. TM-Minifloppy is a trademark of Shugart Associates. Retyonthe Headstrong Company. ^.Shugart 475 Oakmead Parkway, Sunnyvale, California 94086 OUR PRICES ARE TOO LOW TO ADVERTISE! CHECK THEM— CALL TOLL FREE! 800-243-7428 LOOK WHAT WE OFFER! • HAZELTINE Terminals • CENTRONICS Printers • LEAR-SIEGLER Terminals/ Printers • DATAPRODUCTS Printers • ANADEX Printers BE SMART- DONT BUY UNTIL YOU CHECK OUR PRICES! MASTERCHARGE VISA COD PERSONAL CHECK MONEY ORDER ISiiNETRONICS RESEARCH & DEVELOPMENT. LTD. 333 Litchfield Rd., New Milford, CT 06776 Naturally, the members of the group communicated with others at similar academic and industrial research laboratories of the land, by means of conversations at con- ferences and meetings, as well as writ- ten communications of academic pro- fessional organizations. This type of communications between peers is an essential part of any productive research field. In short, word of their ideas got out. Enter the publicist. Now, intellectually and ethically we cannot argue with the following thought: when an opportunity is available to pursue some perceived value, we should go ahead and pur- sue it. There is no way one could complain about this kind of action since it is the essence of human ac- tivities. This attitude is a prelude to all research and innovation. The publicist had all the right words. He was fluent in the jargon of computers. He perceived the enthus- iasm with which the researchers described their activities personally and in print. He thought it would be good to tell the world about what was going on. And that is what he pro- ceeded to do by means of a self- published work which was indeed ahead of the technology of practical general-purpose microcomputers. Up to this point, our publicist had done nothing to which we could ob- ject. He was taking published works, analyzing them and pointing out the implications that these works have. But having caught the enthusiasm, he was beginning to grow impatient. After all, our researcher friends are involved in research, not in en- trepreneurial activities. What our publicist had done, however, was create among people stimulated by small computers an intellectual and commercial demand for an excellent concept. Enter the entrepreneurial program- mer. He is the archetypal program- mer who, given a challenge, immedi- ately proceeds to code. Probably as a result of the ballyhoo created by the publicist, the entrepreneurial pro- grammer proceeded to dig up the published works of our thinker friends. These works were indeed complete, and can be found in the technical journals published during the 1970s. They even include all the information necessary for the entrepreneurial pro- grammer to implement a version of one of the crude, early approaches our researcher friends investigated in their pursuit of the problem. Now, as a published work, these documents were intended for use by other researchers and anyone else with a programming problem. The problem arises when we ex- amine the manner in the which the publicist was going to use the pub- lished works of our researchers. It is one thing to implement a version of a program and sell the particular exam- ple as a toy. But it is quite another thing to name it the same as our researchers' ongoing project, imply in advertising that it is the same (when it is not), and generally imply that its use is sanctioned by its original authors at the research establishment. This is not the same as simply crediting the source in a published work and proceeding to implement a version under a different name and with particular variations. Here, we find the complicity of the publicist and the entrepreneurial pro- grammer as a pair. The publicist now had an opportunity to reach for the brass ring of the software that our research friends had not yet made available to him. He found the ring in the entrepreneurial programmer's product. So, the publicist has recently been pushing the entrepreneurial pro- grammer's product at whatever forum he can find. This situation had been fermenting for some time when all parties showed up at a recent con- vention. The situation came to a head at the convention when our researcher friends arrived on the scene. I became involved to the extent of providing a sympathetic ear in conversation with one of my friends from the laboratory in question. By all reports, the en- trepreneurial programmer later be- came involved in some heated dis- cussion of these points with the pub- licist, my research friends, and several individuals well aware of the issues involved (not including myself). As of this writing, the matter re- mains unresolved. The entrepreneur still has not decided whether to change the name of his program or not, but I hope that, through the mediation of several individuals who know the facts of the matter, he will recognize the error of his ways and, in so doing, learn a bit about the in- 8 Seplember 1980 © BYTE Publications Inc At Intersystems, "dump'' is an instruction. Not a way of life. [Or, when you're ready for IEEE S-100, will your computer JDe ready for you?] We're about to be gadflies again. While everyone's been busy trying to convince you that large buses housed in strong metal boxes will guarantee versatility and ward off obsolescence, we've been busy with something better. Solving the real problem with the first line of computer products built from the ground up to con- form to the new IEEE S-WO Bus Standard. Offering you extra ver- satility in 8-bit applications today. And a full 1 6 bits tomorrow. We call our new line Series 11!'^ And even if you don't need the full 24-bit address for up to 1 6 megabytes (!) of memory right now, they're something to think about. Because of all the perform- ance, flexibility and economy they offer. Whether you're looking at a new mainframe, expanding your present one or upgrading your system with an eye to the future. (Series II boards are com- patible with most existing S-100 systems and all IEEE S-100 Stan- dard cards as other manufacturers get around to building them.) Consider some of the fea- tures: Reliable operation to 4MHz and beyond. Full compatibility with 8- and 16-bit CPUs, pe- ripherals and other devices. Eight levels of prioritized interrupts. Up to 16 individually-addressable DMA devices, with IEEE Standard overlapped operation. User-selec- table functions addressed by DIP- switch or jumpers, eliminating sol- dering. And that's just for openers. The best part is that all this heady stuff is available now\ In our advanced processor— a full IEEE Bus Master featuring Memory Map™ addressing to a full mega- byte. Our fast, flexible 16K Static RAM and 64K Dynamic RAM boards. An incredibly versatile and economical 2-serial, 4-parallel Multiple I/O board. 8-bit A/D-D/A converter. Our Double-Density High-Speed Disk Controller. And what is undoubtedly the most flex- ible front panel in the business. Everything you need for a com- plete IEEE S-100 system. Available separately, or all together in our new DPS-1 Mainframe! Whatever your needs, why dump your money into obsolete products labelled ''IEEE timing compatible" or other words peo- ple use to make up for a lack of product. See the future now, at your Intersystems dealer or call/ write for our new catalog. We'll tell you all about Series II and the new IEEE S-100 Bus we helped pioneer. Because it doesn't make sense to buy yesterday's products when tomorrow's are already here. DoDteo%'steDDDs' Ithaca Intersystems Inc., 1650 Hanshaw Road/RO. Box 91, Ithaca, NY 14850 607-257-0190/TWX: 510 255 4346 The days of complicated, unreUeble, dynamic RAM ara gona: $199. the ultrabyte memory board QC Icomp/etekit I WW y with 16K memory | Netronics consistently offers innovative products at un- beatable prices. And here we go again — with JAWS, the ultrabyte 64K SlOO memory board. ONE CHIP DOES IT ALL JAWS solves the problems of dynamic RAM with a state-of-the-art chip from Intel that does it all. Intel's single chip 64K dynamic RAM controller eliminates high-current logic parts . . . delay lines . . . massive heat sinks . . . unreliable trick circuits. REMARKABLE FEATURES OF JAWS Look what JAWS offers you: Hidden refresh . . . fast performance ... low power consumption . . . latched data outputs ... 200 NS 4116 RAMs . . . on-board crystal . . . 8K bank selectable . . . fully socketed . . . solder mask on both sides of board . . . designed for 8080, 8085, and Z80 bus signals . . . works in Explorer, Sol, Horizon, as well as ail other well-designed S100 computers. I GIVE YOUR COMPUTER A BIG BYTB OF MEMORY | POWER WITH JAWS— SAVE UP 70 S900IV I INTRODUCTORY LIMITED OFFER SPECIAL PRICES/ 1 UNDECIDED? niVA WIW JBK JAWS IN YOUR COMPUTER ON OUR W-OAY MONEY' BACK OFFER (SPECIFY YOUR COMPUTER). CONTINENTAL U.S.A. CREDIT CARD BUYEHS OUTSIDE CONNECTICUT CALL ^^^ From Connscticut Or For Asiistanc IS^NETRDNICSE CALL TOLL FREE 800-243-7428 From Connscticut Or For Asiistancs. (203) 3M-8375 DeOt ^RESEARCH & b9 Idevelopmentltdj 333 Litchfield Road. New Milford,CT 06776 Please send the items checked below: n JAWS 16K RAM kit. No. 6416. $199.95.* n JAWS 16K RAM fully assembled, tested, burned in. No. 6416W. $229.95.* G JAWS 32K RAM kit. No. 6432, (reg. price $329.95), SPECIAL PRICE $299.95.* D JAWS 32K RAM fully assembled, tested, burned in. No. 6432W, (reg. price $369.95), SPECIAL PRICE $339.95.* a JAWS48K RAM kit. No. 6448. (reg. price $459.95), SPECIAL PRICE $399.95.* U JAWS48K fully assembled, tested, burned in. No. 6448W. (reg. price $509.95), SPECIAL PRICE $449.95.* n JAWS 64K RAM kit. No. 6464, (reg. price $589.95), SPECIAL PRICE $499.95.* n JAWS 64K RAM fully assembled, tested, burned in. No. &464W, (reg. price $6^9.95), SPECIAL PRICE $559.95.* n Expansion kit. JAWS 1 6K RAM module, (o expand any of the above in 16K blocks up lo 64K. No. 16EXP. $129.95.* *AII prices plus 82 postage and handling. Connecticut residents add sales (ax. Total enclosed: S - n Personal Check n Money order or Cashiers Check n VISA n MASTER CHARGE (Bank No ) Accl.No. Exp. Dale Signature Print Name Address — . _^ City State n Send me more information _Zip_ tellectual versus commercial realms of endeavor. I have learned that some sort of decision will probably have been made by the time you read this. As for the publicist, he continues in his inimitable style to spin wheels of fancy. In the intellectual marketplace of ideas, the coin of the realm is thought. He or she who owns a reputation as a result of careful thought has a purse full of golden coins ready for the bazaar of ideas. A marketplace of ideas or commerce is a human activity where all parties benefit as a part of trade. One cannot expect willing and bountiful trading when one party plays by a set of rules different and incompatible from the other's set. The productive results of innova- tion and thought carry a requirement for the respect of the rules of the game. One of these rules in the in- tellectual world could be stated "thou shalt not take thy neighbor's reputa- tion as thine own." When you use an idea, credit its source where appro- priate, but do not pretend to imply that your version of the thought is the same. It is perfectly fine to use an inspira- tion from someone's published thought in a commercial product of your own. But be sure that you make clear that the product is your own! Credit the inspiration to be sure. However, if you do not have an en- dorsement from the source of the in- spiration, do not attempt to advertise that thought in any way as a product endorsed by the source of the inspira- tion. Naturally, the ideal state is that in which the researcher is also able to capitalize directly on the results of his or her innovation. By being the first to it and the best able to understand the problem, an inestimable advan- tage is gained over the nonoriginal machinations of those who merely implement the published designs. The main rewards of research must be understood for what they are: an appreciation of difficult problems and the satisfaction of seeing them through to a better understanding. Occasionally in research a com- mercial gold mine is found that ex- udes some of its wealth on the in- novator. But this is a small part of motivation for a life of ideas. The in- novator's reputation is based on a mutual trust and fascination with ideas. Entrepreneurs with a long-term point of view respect this trust by avoiding any semblance of potential violation of that trust. End of com- mentary. A Note The lives of individuals are marked by a series of changes through growth. Enterprises evolve in much the same way. BYTE has gone through many such changes. It began as an idea in the minds of my associates and me five years ago. After much hard work it matured to the point where it now has a circula- tion in excess of 160,000 and an assured future as a member of the family of magazines published by McGraw-Hill. This issue marks the fifth anniversary of BYTE's first issue, published in September 1975. Since BYTE has matured to the point where a founder's day-to-day input is no longer a requisite to the continued health of the venture, I am now in the fortunate position of being able to indulge in my other interests and goals. While continuing with many of the functions at BYTE that have occupied me over the last five years, I will be able to engage in con- sulting activities related to the technology of, and markets for, small computer systems. Such activities have always been of great interest to me. Only with the evident maturity of BYTE and the cooperation of McGraw-Hill am I now able to spend about half of my time on such ven- tures. The day-to-day operations of the magazine will be in the very capable hands of my successors, Chris Morgan and the technical editors of BYTE's staff. My new relationship with BYTE is reflected in a new title on the masthead: "Founding Editor." With my continued intimate involve- ment with BYTE, I shall truly have the best of both worlds. . . .CHB The American Economic System. We should all learn more oboul W. . ^^pn /'v'\ ^ public ieivice message of vA^I . T^' ; This MogojineS. the Adveflising Council CSoKll '-'^y StheUSD. i DepQttmenl ol Commerce 10 September 1980 © BYTE Publications Inc Circlis 3 on inquiry card. Why^^ m TfyouTaaveaii^^^^gl devices, itwitla that Lcorapat- to a V--- .„"„ modem to use ^ ^^^ ^^^Serfacelsoftw^^^^l^es, and senalinter Viandslaatang routine BO yo^lS^the interface software touting ce. para lUei »»_,,„ count c. iunectyof Tbe enough ^^! .ua^ prograininaD«= ^^^g sirnu- . ^°^f ?S coutto^-?^^^.„^'Sntrolltog V,andsba\^i^S^are\istmg tor CO ^^_ ^XfA^^S^^^^^CI^SSgi^ aterfac* to both se«^, Tind oi ir^"°^^Thebeginning °^f 'Sal and parallel Hme.That's^*ri!?nductssincetbeta^ej^^pROM>se^^^^^^^ time :^-^^'^'::^^v^^^ e-tbserialVK-^;^,onw-e— ^ cables, an See *e ^MO atJ/.^^^^^,,,on. 2190 Paragong^, 95131 or cor Maybe we can save you a calL Many people have called with the same questions about the AIO. We'll answer those and a few more here. GU Does the AIO have hardware handshaking? A: Yes. The serial port accommodates 3 types— RTS, CTS, and PCD. The parallel port handles ACK, ACK, BSY, STB, and STB. Qi What equipment can be used with the AIO? A: A partial list of devices that have actually been tested with the AIO includes: IDS 440 Paper Tiger, Centronics 779, Oume Sprint 5, NEC Spinwriter, Comprint, Heathkit H14, IDS 125, IDS 225, Hazeltine 1500, Lear Siegler ADM-3,DTC300,AJ84L Gt: Does the AIO work with Pascal? A: Yes. The current AIO serial firmware works great with Pascal. If you want to run the parallel port, or both the serial and parallel ports with Pascal, order our "Pascal Patcher Diskl' GU What kind of firmware option is available for the parallel interface? A: Two PROM's that the user installs on the AIO card in place of the Serial Firmware PROM's provide: Variable margins, Variable page length, Variable indentations, and Auto-line-feed on carriage return. Gt: How do I interface my new printer to my Apple using my AIO card? A: Interconnection diagrams for many popular printers and other devices are contained in the AIO Manual. If your printer is not mentioned, please contact SSM s Technical Support Dept. and they will help you with the proper connections. Qx I want to use my Apple as a dumb terminal with a modem on a timesharing service like The Source. Can I do that with the AIO? A: Yes. A "Dumb Terminal Routine" is listed in the AIO Manual. It provides for full and half duplex, and also checks for presence of a carrier. GL What length cables are provided? A: For the serial port, a 12 inch ribbon cable with a DB-25 socket on the user end is supplied. For the parallel port, a 72 inch ribbon cable with an unterminated user end is provided. Other cables are available on special volume orders. ^pple Computei^' inc. The AIO is just one of several boards for the Apple that SSM will be introducing over the next year. We are also receptive to developing products to meet special OEM requirements. So please contact us if you have a need and there is nothing available to meet it. SSM Microcomputer Products 2190 Paragon Drive San Jose, California 95131 (408) 946-7400 Them '4 rz iii ip. i^.A- SF^I^^^^V'' ^ ^^.> '- -^] J^-. ht and the Afffie. - I, If you could talk to Thomas Edison, he'd tell you what it was like to turn the lights on in 1879- You could tell him about some bright ideas of the 20th century. . . particularly a technological phenomenon that can handle everything from solar heat control to lighting your home via voice command. The Apple personal computer. Expand your own inventiveness with the alwayS'^expandable Apple. Take a look inside your local computer store. There's a range of Apple systems for you . . .whether you want expansion capabilities of four or eight accessory slots. . .or memory expandable to 64K bytes or 128K bytes. With this kind of flexi- bility, the possibilities for creating your own computer system are endless. Want to add an A to D conversion board? Apple makes it happen. Want to plug into time sharing, news and elec- high speed and low cost. No wonder this drive is the most popular on the market. But now Apple goes one better with the DOS Tool Kit. A series of utility programs, it gives you the freedom to easily design 280hxl92v graphic displays in a palette of living color . . . depending on your choice of Apple system. Edison was first with the movie camera and projector. Now, with Apple's DOS Tool Kit, you can be first to work wonders with colorful creative animation. Imagine the broadest line of software programs ever. Apple's broad line of peripherals is equalled only by the most extensive line of software you'll find in the personal computing world. Since more than 170 companies offer software for the Apple family, you can have one of the most impressive program libraries ever. When you write your own programs, your Apple speaks creatively in BASIC, With Apple, Edison could've written a program to determine why some filaments burned longer than others. tronic mail services? Apple does it all. Because Apple is the most popular per- sonal computer with the least complicated interface, over 100 companies supply peripherals for the Apple family. . . includ- ing an IEEE 488 bus for instant control. Disk drives, a tool kit and creativity in color. Apple was one of the first to use disk drives for increased performance and application versatility Today, our 51" disk drive ofiers high density (143K bytes^ Circle 4 on inquiry card. •mm- r I _ J- Edison had the first movie camera. . . and Apple has the DOS Tool Kit that takes you into the colorful world of animation. Pascal, FORTRAN, PILOT and 6502 assembly language. Use these languages to score a sonata. Apple will play back your musical master- piece on its built-in speaker. Edison listened to his voice on a revolutionary phonograph in the 1800s . . . now you can listen to the - , sounds of today with Apple's i inventive family of personal computers. i, Where to find even more illuminating Apple experiences. There's always something new being invented at Apple to set your imagination soaring. And there's always an expert to tell you all about it in _ detail. Your Apple dealer. If you already own an Apple, there's a whole future ahead to challenge man, mind and machine. If you're considering a personal com- puter, stop by the computer store and compare. Apple's reliability, proven perfor- mance and recognized technological leader- ,^ ship will help you see the light. Don't let history pass you by Visit your nearest Apple dealer, or call 800-538-9696. r In California, 800-662-9238. ill ZI _ 1 :applG Gomputcr Liifeps Cromemco Lauded After reading of the many horror stories of poor documentation and ser- vice within the microcomputer industry, I want to point out the excellent treat- ment I have received from Cromemco Inc. In July, 1979, I purchased a System III with four disk drives and most of Cromemco's available software. Lately, I have added the 3102 Terminal and the 3355A Printer. I have found the documentation very complete. The manuals for the above products form a pile 10 inches high. When I first received the System III, I had some difficulty using the third and fourth disk drives. Because I was not too familiar with the system, and the drives worked in certain situations, I concluded that the drives were probably OK, and NEW OPEN FRAMES AND SWITCHERS... at our same old tow prices! "S^^- iiriiiiilillliiilllll More new open frames to choose from - plus new special-purpose models for specific applications such as Microprocessor and Floppy- Disk systems. Also, Power-One now offers a growing line of switching D.C. Power supplies with the same high quality and reliability as our open frame models. Newl980-81 Product Catalog, plus our new Tour Guide. Phone or write for your copies today! > PRODUCT lii^^ .ooc^ .««^^ ""i^ipffijier-i muuer-ane a.c poiuer suppues Power-One, Inc. • Power One Drive • Camarillo, California 93010 Phone: (805) 484-2806 • (805) 987-3891 • TWX: 910-336-1297 that I did not understand some detail of the system's operation. Several weeks ago I was forced to conclude that the drives were defective, and I called Cromemco. Even though the warranty on the drives had expired six months earlier, they accepted the responsibility for the defect and had the repaired drive back to me within two weeks. In addition, I have begun receiving updated software on disks. The software has been considerably enhanced. There is no charge for the additional features. I don't even have to pay for the disks. Finally, though I had done a lot of programming on large systems and am quite knowledgeable about electronics, I had never worked with FORTRAN or COBOL, and initially I was not up to speed on the system aspects of microcomputers, especially the use of the disk drives. My questions were always answered courteously, even when they were naive, and my tele- phone calls were always returned. The equipment is conservatively designed and well constructed. The soft- ware and operating system are capable and straightforward to use. I have never been more pleased with all aspects of a purchase than I am with my Cromemco system. Wil Schuemann Sage Instruments 501 Maple St Parkersburg WV 26101 Making Music Hal Chamberlin's article on "Advanced Real-Time Music Synthesis Techniques" (April 1980 BYTE, page 70) was timely and informative. Since I have been experimenting with similar tech- niques for several years, I can vouch for the viability of his procedures, but I would also like to comment on several points raised in the article. I agree that most digital synthesizers on the market do not have sufficient control for either education or serious musical work. A recent informal poll of musicians showed that the majority desired at least four voices, and com- plete control over envelope, timbre, loudness, and pitch for these purposes. While Mr Chamberlin's technique pro- vides for the important change of timbre with time that is so often neglected, his sequence table is stepped through at a rate determined by the tempo setting, so a voice will behave differently at slow Circle 6 on inquiry card. ^^^ TRS-80* Model i Computer Owners Store More Data on a 5"-Disk Than on an 8"-Disk % The Doubler^': Percom's new proprietary double-density adapter for the TRS-80* com- puter. ^< Plug the DOUBLER™ into the disk controller chip socket of your Expansion Interface and . . , Store up to 354 Kbytes of formatted data on five-inch disks. • Increase formatted storage capacity of your minidiskettes from Wi to almost 4 times. • Use with standard 5-inch drives rated for double-density operation. • The DOUBLER"' reads, writes and formats either single- or double- density disks. • Proprietary design allows you to continue to run TRSDOS*, NEW- DOS ^ Percom OS-80'^' or other single-density software without making any changes to software or hardware. Mini-Disk Systems More storage ca- pacity, higher re- liability — from Per- com, the industry leader. One-, two- and three-drive configurations in either 40- or 77-track format, start- ing at only $399. PRICES AND SPECIFICATIONS SUBJECT TO CHANGE WITHOUT NOTICE. • Includes DBLDOSr' a TRSDOS* compatible double- density disk operating system. • CONVERT utility, on DBLDOS"' minidiskette, converts files and pro- grams from single- to double-density or double- to single-density • Plug-in installation: No strap- ping. No trace cutting. Restore your Expansion Interface disk controller to original configuration by simply removing the DOUBLER'" and re- installing the original disk controller chip. I 1 I PERCOM DISCOUNT COUPON i worth $20 toward The Purchase of a DOUBLER^' Coupon No. BlOlOl Expires December 30, 1980 Void where prohibited by law, I I I I I J • The DOUBLER™ circuit card includes high-performance data separator, write precompensation cir- cuits for reliable disk read operations — even on 77-track drives. Introductory price, including DBLDOS"^" and format conversion utility on minidiskette, only $219.95. Use the coupon for even greater savings. Call toll-free, 1-800-527-1592, for the address of your nearest dealer, or to order direct from Per- com. tPercom TFD-200" drive, OS-SOD" operating system PERCOM DATA COMPANY. INC. 211 N. KIRBY GARLAND. TEXAS 75042 [214)272-3421 fw trademark of Percom Data Company, Inc. * trademark of Tandy Radio Shack Corporation which has no relationship to Perccm Data Company. 4; trademark of Apparat Company, [foe. and fast tempi. Most musical instru- ments, however, vary their amplitude (tremolo), pitch (vibrato), and timbre (we need a word for this — tambolo?!) at a rate almost independent of the score tempo, but in a manner suited to the in- strument and type of music played. This could be accomplished by adding one more counter for vibrato-tremolo- tambolo update independent of the tempo counter. The computation of signal/noise (S/N) ratios for synthesizers can be misleading. If the intent is to reproduce a musical sound, then a resolution of 60 to 80 dB is a necessity. However, if the intent is to produce music from scores, a much lower S/N ratio can be tolerated if the distortion partials are harmonic. After all, the "noise" content of flutes or harpsichords can be very high, but is considered part of the natural sound of the instrument. Eight-bit D/A (digital-to- analog) converters and 256-byte wave tables do seem adequate for music- synthesis experimentation, at least until computer memory and power become somewhat cheaper. Mr Chamberlin's method of generating up to 8 K bytes of waveform tables is well suited to single D/A output but re- quires extensive dedicated storage, plus time spent in creating the wave tables. This can be markedly reduced by noting that the ratios of the harmonic amplitudes remain nearly constant for a considerable fraction of the note dura- tion for many instruments. This suggests that if the envelope amplitude were pro- vided by a separate D/A converter and its output were multiplied by a waveform multiplying D/A converter, that many fewer waveform tables would be necessary since they would contain only waveshape information, not envelope information, and they could better be reused for other voices. The additional $10 for a multiplying D/A converter would be more than offset by the savings in memory. Incidentally the envelope "volume control" must precede the waveform D/A converter, not follow it as implied in the text, so that the required envelope filter does not cut off the harmonics of the waveform. Finally, there is a very serious prob- lem with the low sampling rates (6.9 kHz to 8 kHz) mentioned in the ar- ticle. Suppose that the highest fun- damental desired is Cb ( — 2100 Hz) and that at least four harmonics are necessary to produce the desired timbre (both of these figures are very conser- vative). Then the highest frequency pre- sent in the sampled waveshape is = 8400 Hz, and since a "headroom" of at least 10% is needed for the anti-aliasing low- pass filters, the filter stop-band edge can A CREATION OF COMPUTER HEADWARE TM (Wm! Hm^ All That Stuff get InThml) /\ sophisticated, self-indexing filing system- flexible, Infinitely useful and easy to use, that adapts to your needs, WHATSIT comes ready to run on your Apple, NorthStar, or CP/M computer. See your dealer. . . or write or call: All l"" c pl"' ILUUmAT P,0, Box 14815 • San Francisco, CA 94114 • Tel: (415)621-2106 be no lower than « 9300 Hz. So for these requirements, the sampling fre- quency must be at least 18,600 Hz by the Nyquist criterion. A lower sampling frequency will: 1) produce aliasing distortion, or 2) limit the highest fundamental to a smaller value, or 3) force you to accept fewer harmonics in the waveform (at least at higher pitches) if aliasing is to be prevented. A solution might be to use different waveform tables with fewer harmonics for the higher pitches, but this further complicates the algorithm, requires more waveform storage, and introduces pitch breaks into a voice's timbre like that of an organ mixture stop. The length of my comments reflects favorably on the thought-provoking nature of this article. Mr Chamberlin's work should be of great help to new ex- perimenters in the field of music syn- thesis, and will, I hope, stimulate discus- sion on this topic. Donald L Shirer Director, Computer-Based Instruction Laboratory University of Arizona Tucson AZ 85721 Suspected Brain Malfunction Disables Op Code Equivalence My article in the June 1980 BYTE "Z80 Op Codes for an 8080 Assembler" (page 64) contains a monumental goof, which I can only explain in terms of brain malfunctions and the like. To define a symbol such as XAF as being equivalent to hexadecimal 08, one doesn't write "XAF DB 08H"; obviously one writes "XAF EQU 08H". Table 2 on page 70 makes sense only if you put EQU statements between the columns, not DBs and DWs as I said. Judging from letters I have received, BYTE readers aren't dumb enough to believe everything they read, thank goodness. My intelligence seems to have gone down about 10 DB or if you like, 10 DW. Sorry, people. Bill Powers 1138 Whitfield Rd Northbrook IL 60062 Z80 Op Codes... The Continuing Saga There is an error in the article "Z80 Op Codes for an 8080 Assembler" which appeared in the June issue of BYTE. On page 64 the statement "XAF DB 08H" should read "XAF EQU 08H". As writ- Seplember 1980 © BYTE Publications Inc Circle 7 on inquiry card. LOW COST RELIABILITY SPEED FINALLY AN ALTERNATIVE TO DISKS THEEXATRON STRINGY FLOPPY (MASS STORAGE SUBSYSTEM) $299.50 INFORMATION PACKAGES AVAILABLE NOW FOR: APPLE OSI RS-232 PET KIM/SYM/AIM STD-BUS TRS-80 S-100 OEM exatron CALL OUR HOT LINE TODAY 800-538-8559 TO REQUEST AN INFORMATION PACKAGE EXATRON, INC. ■ 181 COMMERCIAL STREET SUNNYVALE, CA 94086 Circle 8 on inquiry card. BYTE September 1980 17 Circle 9 on inquiry card. Haw some Sfeat memories. 16K PROM boards. ■ PROM card has 2708-tYpe mcmorY ■ Quality board construction ■ 0-4 wait states ■ Address any 4K group to any 4K boundary ■ Control up to 8 banks of memory ■ Fully assembled and tested ■ PRICE— $300 (California residents add 6% sales lax) Expandable 5 MHz RAM boards. 8— 32K expandable RAM board uses TI 4044 memory ■ Runs at 5MHz ■ Fast 250ns access time ■ Bank select ■ Address any 4K block to any 4K boundary ■ Quality board construction PRICE— 8K— $210; 16K— $378; 24K— $570; 32K— $744; 8K add-on kits— $162 (California residents add 6% sales tax) Call or write Artec for details /1RTGC GLGCTROMIC9JMC. 605 0l(j County R(j., San Carlos, CA 94070 Telephone (415) 592-2740 ten, XAF is assigned the address to which a byte of value 8 is assembled. The actual intent is to assign XAF the value 8. The pseudo-operation EQU serves the function of an "equivalence statement." Using mnemonic conventions such as those developed in this article, it is simpler to use Z80 code on an 8080 assembler. However, the readability of the resultant programs will be poor. I would suggest the use of macroinstruc- tions in lieu of the DW...DB sequences. If a macroassembler is not available, then a preprocessor could be created to expand the Z80 instructions into se- quences understandable to an 8080 assembler. Either way, the source code will retain readability and will probably be less error-prone. I believe that the basic software tools make a tremendous difference to the quality of software produced. Every Z80 computer should have at least one good Z80 assembler. Lest I seem too critical, I did enjoy this article very much. Anthony Skjellum 1695 Shenandoah Rd San Marino CA 91108 Information Please Are any of my fellow BYTE readers willing to share information with me on interfacing microcomputer systems to the IBM Models 50 or 60 electronic typewriters? I would like to use my Model 60 as an output printer, and I would appreciate some advice, if any is to be had. Thanks very much. Michael Pinneo 3757 Vienna Dr Aptos CA 95003 SelectrJc Infornnation Sought Do any readers of BYTE know of any commercial devices that can interface a Radio Shack TRS-80 to an old model of an IBM Selectric typewriter (a Model 71)? I would also like to hear from anyone who has bought an already- interfaced Selectric from McClain and Associates or from Worldwide Elec- tronics. Thank you. N Vijayan 1332 Notre Dame Dr Davis CA 95616 Performance Improvements I have studied the article 'TRS-80 Performance Evaluation by Program Timing," by James Lewis (March 1980 BYTE, page 84) with interest. I am only concerned here with the Level II BASIC program. The largest number a figure is divisible by without becoming redundant is its square root. If we include the statement: 20C = INT(SQR(A)) + 1 and change the second FOR-NEXT loop to: 30 FOR B = 3 TO C STEP 2 we will find the program runs much faster. For example, in the original pro- gram 9901 goes through the inner loop roughly 4500 times. Using the modified program, the second loop is only used 50 times which is ninety times faster. I find this version will run in about 25 minutes. Here is a listing of the modified pro- gram: 1 CLS:PRINT"1 2 3"; 10 FOR A = 5 TO 10000 STEP 2 20 C = INT(SQR(A))-h1 30 FOR B = 3TOCSTEP2 40 D = A/B 50 IF INT(D)=DTHEN NEXT A 60 NEXT B 70 PRINT A; 80 NEXT A Brian Glover POB 2102 Inuvik, Northwest Territories XOE OTO, Canada More Improvements Mr Lewis, in his article in the March 1980 BYTE, seems to compare two dis- similar computers. It was unclear to me what could be gained by this kind of comparison. The run time of a program is not only sensitive to the computer be- ing used, as well as the programming language, but also to many other seem- ingly trivial factors. For instance, Mr Lewis wanted to find all the prime numbers less than 10,000. His method was to divide by successive odd numbers. If division occurred without a remainder, then the number being divided is not a prime. The prob- lem was that he kept dividing until the divisor was half of the dividend. For ex- ample, to check a number that was almost 10,000 he would keep dividing by numbers until he has used up all those less than 5000. It is easy to show that the time to stop is at the square root of the number, not half the number. He could have stopped after checking numbers up to 100 instead of 5000. This is true because, if some number greater than 100 is divided without a re- mainder, the quotient would be some number less than 100 and this would have been revealed before ever reaching 100. 18 Seplember 1980 © BYTE Publications Inc Circle 10 on inquiry card. x-io- IL fe=5?=i^- Mountain Hardware makes more peripherals for the Apple Computer than Anybody. INTROLX-10 tights and edules and energy conservation. Compfete applications pacliciii through firmware. Six sockets if ROM equivalents. Six or any com- „., .„..^. . „«. . «w »«.-« aionce. Scratch-pad RAM and two TTL connectors. Special 2K ROMs available for powerful system enhancement: Keyboard Filter ROM— COPYROM— Others coming soon. icsystem le only on ;nframe com- iiai instrumental iMMsj.i^ oyiiun.ioitci ayoi^m. 16 voices in stereo. Instrument definitions simulate the sound of real instruments— and more. Fully programmable waveforms. Envelope Con- trol. Composition system— sheet music input using standard music notation. Chords and multi-part scoring up to 16 voices. A true instrument that anyone with an Apple can^ ,to analog output. Ion. Super-fast 8^ sec. conversion time. Monitor and output to the real world. All on one card. EXPANSION CHASSIS auiy power supply, tasy lo use. Aoaress cards in Expansion Chassis the same way as in your Apple. Only one additional command to specify in Apple or in Expansion Chassis. Compatible with all Apple peripherals. MOUNTAIN HARDWARE has the most compre- hensive line of Apple peripherals available. Anywere. From anybody. We know the Apple inside and out and are committed to providing the most innovative and unique products to expand and enhance its capabilities and use. After all. we were the first company to make an Apple peripheral— except Apple Computer. The message is simple. If you have an Apple, you need to know MOUNTAIN HARDWARE. Available at Apple Dealers worldwide. Mountain Hordwore Leadership in Computer Peri plierals 1^^ A Division of Mountain Computer, Inc. 300 Harvey West Blvd. Santa Cruz, CA 95060 (408) 429-8600 MORE PERIPHERALS? Send me information. NAME ^«*^, 1 wrote the following short program, PRIME, and ran it on my North Star computer in about 24 minutes: 10 REM PRIME 20 FOR K = 5 TO 1 0000 STEP 2 30 1 = 3 40 IF INT(K/I) = K/l THEN 80 50 1 = 1 + 2 60 IF I t 2<=KTHEN 40 70 !K 80 NEXT 90 END Division for a conventional microcom- puter for which double precision is necessary is slow, and the fewer occur- rences in a program the quicker the pro- gram will run. When I eliminated one division in my program to produce PRIME 2, the running time was reduced to 17 minutes: 10 REM PRIME 2 20 FOR K = 5 TO 10000 STEP 2 30 1 = 3 40 X=KJ\ 50 IF INT(X): = X THEN 90 60 1=1 + 2 70 IF 1 t 2< = K THEN 40 80 IK 90 NEXT 100 END But the most important consideration is how the translator works; an inter- preter is devilishly slow. A computer will run considerably faster because machine code is actually executed. I wrote a short Pascal program for my North Star, primes, and was surprised to find that it executed in 1 minute and 46 seconds. (See listing 1.) Mr Lewis' results for the large IBM computer was 1 minute and 19 seconds using a PL/I compiler. Does this mean that my microcomputer is almost equiv- alent to this huge IBM machine? I think not. Comparisons of this sort do not prove much; they just show how many vari- ables are involved in determining the time it takes to run a program! Ivan Flores Flores Associates Computer Consultants 108 8th Ave Brooklyn NY 11215 Comparisons of this sort may not prove much, but you (and many other readers) found the idea interesting enough to experiment with. Evaluation of performance encourages programmers and designers to work their crafts with efficiency, and to search for the elegant- ly simple solutions that improve .... CPF Listing 1 program primes; {writes out a number of primes} var i,j,k, n : integer; begin k := 2; while k < = 5000 do begin n := 2*k + 1; j: = 1; i:= 3; while (i * i < = n) and (j = 1) do begin if n mod i = then j: = else i: = i + 2; end; if j = 1 then write(n, ' '); k := k + 1; end; end. Pascal Precision The letter from Martin Berman con- cerning numerical precision in UCSD Pascal (BYTE, June 1980, page 17) struck one of my current concerns. The actual precision available in UCSD Pascal is 7.2 decimal digits; ie: the data type real will accommodate integer values as large as 16,777,216 (2^'*) exact- ly. However, the output routine is limited to six significant digits. To print the remaining available 1.2 digits will re- quire either a revision to the system- output routine or an output routine custom-made for the application. I am not privy to the design process at UCSD, but suspect that this is an at- tempt to "protect" the user from round- off error. I, for one, deplore such at- tempts at protection since the user who actually knows what he is doing is forced to "program around" the system. A reasonable precaution is to give no more precision than the system has (eight digits in the case of UCSD Pascal), although even this is open to question — a fellow programmer was once caught by this type of "protection" even though he was using only powers of two which are exactly represented throughout the range of the system. Incidentally, there is a routine available for determining the actual preci- sion of floating-point routines. It may be found in Pascal News, number 13 (December 1978). I enclose a copy of the code as I ran it on my UCSD Pascal system, along with the output it generated. Industrial quality components for S-100 system builders, from California Computer Systems. NskCoairoHer. Single aihJ douDk^ density controller for up iu four 5^ " or S'"' single-sided drives, or two double-sided drives.' Shipped with CP/M 2.0, the controller reads and writes IBM-standard single density. Automatically determines disk density- single or double. Supports PerSci auto eject, plus fast-seek for voice coil systems. 2810 Z80 CPU Board.Capable CPU for SlOO Systems operates at 2 or 4MHz, is fully Altair/ Imsai compatible. Z-80 monitor is available separately. Includes auto addressing to 4K boundaries, plus a serial port for serial devices, including terminals and printers. Supports both front-panel operation and power-on memory jump, plus wait-state gen- eration for slower memories. Compatible with proposed IEEE S-100 standards. 2032A32K Static RAM. Fast static memory operates without wait states at a full 4MHz. Supports full and partial bank select, for expansion beyond 64K. Addressable in 8K blocks at 8K boundaries. Address and data lines are fully buffered, and there are no DMA restrictions. 201616K Static RAM. Fully buffered board features 2114 static RAMs for +5v operation. Bank select available by bank port or bank byte, for system expansion beyond 64K. Addressable in 4K blocks at 4K boundaries. LED indicators for board selection and bank selection. Available in 200, 300, or 450 nsec versions. All versions support 4MHz operation with no wait states. 22(K)AMainframe. Rock solid, heavy gauge cabinet includes 12-slot, actively terminated S-100 motherboard, fan, and power supply. Power supply features 105, 115, or 125 volt AC input power; provides +8vDC at 20 amps, ± 16v DC at 4 amps. Available in five colors. Includes convenient, front mounted, lighted reset switch. 2501AMottier Board. 12 slots, actively terminated, with all S-100 connectors included. Distributed power line bypass, low induc- tance interconnect— extremely low bus noise. Prototype Boards. Four high quality prototype boards: Solder Tail, Extender/Terminatoi; Wire Wrap, and Etch. P2802AA 6502 CPU. Stand-alone CPU generates fully S-100 compatible I/O signals; executes 6502 machine language. Operates at 2MHz; capable of DMA operation. Available nationally. California Computer Systems industrial quality S-100 products are available at over 250 computer retailers. Volume customers should contact the marketing department at CCS. CCS. Industrial standards. Circle 11 on inquiry card. E the S-3^ We mass-produce S-100 products to deliver industrial quality, at industrial prices. You systems builders who need top quality, full featured, ivorkhorse S-100 building blocks at the most competitive prices now have a source. California Computer Systems. Industrial quality means top grade materials, com- ponents, and assembly, plus complete testing for absolute reliability. Industrial quality means solid designs, a full complement of the important features you require, and a product line that delivers performance. Industrial pricing comes from mass production. We buy at the right prices, and build in quantity, using state-of-the-art facilities and techniques. Including complete bum-in, for full performance right off the shelf. Our industrial point of view means you get higher performance, greater reliability, and lower prices. If these are features you would like to see in your S400 system, see things our way. Because for serious users with serious uses for the S-100, these are the industrial standards. ^ i California Computer Systems 250 Caribbean Sunnyvale, CA 94086 [408} 734-5811 ' .i^i' ^ -'■■■■■•* Circle 12 on inquiry card. SUPERBRAIN 32K or 64K (Double or Quad Density units available). Uses two Z-80 CPU's. Commercial- type terminal with 12" monitor. Dual double density minifloppies. Over 350 kilobytes of storage (twice that with quad density drives). Two serial RS232 ports, I/O ports standard. Expandable with optional S-100 S-100 inter- face. Comes with CiP/M"'''^ 2.2 operating sys- tem. MiniMicroMart includes BASIC inter- preter and can supply a wide range of CP/M Development and Application software. W/32K Double Density, List $2995 . $2685 W/64K Double Density, List $3345 $2883 W/64K Quad Density, List $3995 $3595 64K Special Quad Version $3395 INTERSYSTEMS formerly ITHACA AUDIO DPS-1, List $1795 LIMITED TIME $1299* The new Series II CPU Board features a 4 MHz Z-80A CPU and a full-feature front panel. 20- slot actively terminated motherboard, with 25 amp power supply (50/60 Hz operation, incl. 68cfmfan). COMPLETE SYSTEM with InterSystem 64K RAM, I/O Board w/priority interrupt and double density disk controller board. Full 1-year warranty, List $3595 0NLY$2895* Above less disk controller, $3195 $2539* * Limited Time offer expires Sept. 15, 1980. HEWLETT-PACKARD HP-85A Desk-Top Computer Call for Price! .' ,' 1 11 M 1 M n 1 ; ( ( r n r It 1 1 11 1 HH f I I I ! 1 i 1 . ' M""""i \\\W\x 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 1618 James Street Syracuse, NY 13203 (315) 422-4467 22 September 1980 © BYTE Publications Inc Listing 1 program representation; var base, numberof digits, i rounding epsilon : integer; : boolean; : real; procedure enquiry (var radix, digits : integer; var rounds : boolean); var number, increment : real; begin (*find large integral value just beyond integer limits*) number : =2; while (((number+ l)-number) = 1) do number ; = number * 2; (*end while*) (*manufacture the next largest real value*) increment : = 2; while ((number + increment) = number) do increment : = increment * 2; (*end while*) (* subtract these to give radix of representation*) radix := trunc((number + increment) -number); (*see if it rounds or truncates by adding (radix - 1)*) rounds : = ((number + (radix - 1)) NEQ number); (*work out how many digits in mantissa*) digits : = 0; number : = 1 ; while (((number + 1)- number) = 1) do begin digits : = digits + 1 ; number : = number * radix; end; (* while*) end; (*enquiry*) begin (*find out basic properties*) enquiry(base,numberofdigits, rounding); writelnC Base = ',base); writeln(* Number of digits = ',numberofdigits); if rounding then writelnC Rounded') else writelnC Truncated'); (*endif*) (*compare the precision bounds*) epsilon : = 1 ; for i : = 1 to numberofdigits do epsilon : = epsilon/base; (*end for*) if rounding then epsilon : = epsilon/base; (* print the best and worst precision*) writelnC Best and worst precisions are ', epsilon, (epsilon *base)); end. My hard-copy terminal does not have greater-than or less-than symbols. Thus 'TMEQ" is inserted for the Pascal "not equal" symbol. Base = 2 Number of digits = 24 Rounded Best and worst precisions are 2.98023E-8 5.96046E-8 Fred Crary 7750 31st Ave NE Seattle WA 98115 May We Suggest a Gasp Mask? Philip K Hooper is not alone. I too noticed the foul odor of the magazine. (See Letters, April 1980 BYTE, page 16.) Not only do I love computer science, but I love my body, and my health is paramount. I therefore abstain from the inhalation of foul vapors and fumes. A Healthy Minority Jon Dattorro 1379 Kingstown Rd Apt lA Kingston RI 02881 / am told that our printer used an im- proper glue to hind the pages together, causing the unusual smell. The printer has promised to henceforth use a dif- ferent glue, and we expect that the odor problem will not recur.... RSS ■ Circle 13 on inquiry card. When It Comes To Add-on Memory... LOBO Has It All. LOBO DRIVES manufactures a full line of S-100 computer compatible disk drives. All drives are software compatible with most S-1 00 disk operating systems and applications software programs. Only LOBO DRIVES offers you the variety and choice of floppy and fixed disk drives. Choose from 5Va and 8-inch floppies, 5/4 and 8-inch Winchester technology fixed disk drives, and several Floppy/Fixed disk combinations. Each LOBO DRIVES system is thoroughly tested and burned-in and has the famous LOBO DRIVES One Year, 100% Parts/Labor Warranty. MODEL 400 SVa-INCH FLOPPY DISK MEMORY SYSTEM A high-speed (298) Msec Access), high- reliability (8000 hrs MTBF), low-cost floppy disk memory system. It is available in both soft and hard sector formats, and a choice of single or double density configurations. • Up to 220 KBytes Capacity • Single/Double Density • Soft Sector Format • Complete Software Compatibility MODEL 800/850 DUAL FLOPPY DISK DRIVE MEMORY SYSTEM LOBO DRIVES offers you a choice of single-sided, single or double density (Model 800) or double-sided, single or double density (Model 850) dual 8-inch memory subsystems. Each system comes complete with chassis and power supply, cables, controller and interface. • Compatible with Most S-1 00 DOS Systems • Up to 3.2 MByte Capacity MODEL 1850 DUAL FLOPPY/FIXED DISK MEMORY SYSTEM No more worries about back-up. LOBO DRIVES has combined the latest state-of- the-art Winchester technology with the pro- ven reliability and dependability of its Model 850 8-inch floppy disk drive to bring you the ultimate in memory expansion for your S-100 computer. The Model 1850 is the ideal memory system for small business and word processing applications. • 5 or 10 MByte Fixed Disk Capacity • 1 .6 MByte Floppy Disk Capacity • Software Compatibility • Sealed Environment • Winchester Reliability • 70 Msec Average Access Time MODEL 950 DUAL FLOPPY/FIXED DISK MEMORY SYSTEM All the advantages of Winchester technology fixed disk memory: large capacity (6.38 MBytes), high speed (170 Msec avg. access time), and extended reliability, combined with the convenience of a built-in floppy disk back-up in one cabinet. Only LOBO can bring you the storage capacity of 16 mini-floppies at a fraction of the price. • The Storage Capacity of 16 Mini- Floppies • Built-in Back-up • 1 70 Msec Access (Avg) • Software Compatibility See your nearest dealer, call, or write for the complete LOBO DRIVES story., find out just how competitively priced a quality drive can be. I INTERNATIONAL 935 Camino Del Bur Goleta, California 93017 (805) 685-4546 Telex: 658 482 nil nizsijRD <::>»S3 'I fM m m ■"■^■"'"^ HJAJARI OMPUTING ATARI: PERSONAL COMPUTER START WITH A BETTER COMPUTER. Atari personal computers have built-in capabilities you can't even add on to many other personal computers. Three programming formats (slip-in ROM cartridges, disk and cassette). A 57-key upper/lower case ASCII keyboard with 29 keystroke graphics . 128 colors and hues. Four separate sound channels and a built-in speaker. Four game and graphics controller ports. A built-in RF modulator. FCC approval for connection to any TV Plus, nationwide Atari Authorized Service Centers. And more. ADD MEMORY The ATARI 800™ comes with 16K of memory. Expand up to a full 48K of memory with 8K or 16K RAM Memory Modules™ you install yourself. In less than a minute. The ATARI 400™ is supplied with 8K of RAM which can be expanded to 16K at Authorized Service Centers. Both models may be expanded to 26K of ROM with slip-in ROM cartridge programs. ADD PERIPHERALS. Atari peripherals are specifically ©1980, Atari. Inc. O A Warner Communications Company Alan reserves the righi to make changes to products or programs without notice designed to complement your system. Add the ATARI 410"' Audio-digital Program Recorder. Add disk drives (single or dual double-density*). The ATARI 800 individually accesses up to four drives. Add the ATARI 850™ RS232 Interface Module. Add high-speed 40 or 80-column dot-matrix printers, or, a 40-column thermal printer. Add an acoustic modem for remote data access. Add a light penf And there are more Atari peripherals on the way. ADD PROGRAMS. Atari's rapidly expanding software library includes some of the most useful, enlightening and entertaining programs available. (Some programs may require more than 16K RAM.) • Personal Finance and Record Keeping. Sophisticated investment analysis programs, including bond analysis, stock analysis, stock chart- ing and mortgage and loan analysis. ♦Available Fall, 1980 Circle 14 on inquiry card. 0e>i<-F^>^gi SYSTEMS THAT GROW WITH YOU • Personal Interest and Development. Conversational lan- guages* Music composition. Touch typing. Biorhythm. And more. » Professional Applications. Graphics, statistics and programmable calculator programs. Plus VisiCalc,t the "what if" problem solving program. • Education. ATARI Talk & Teach"' programs offer instruction from primary through college level. Plus, instructive games for all ages. ► Information & Communication. Turn your Atari into an interactive terminal. Access stock quotations, newsservices and other useful data banks. Transmit and receive data over regular phone lines. And more. ' Entertainment. Colorful, exciting programs include Star RaidersJ" Chess, Blackjack... and many more. ■Trademark: Personal Software, Inc. • Programming Languages. An ATARI BASIC cartridge is included. An Assembler/ Editor Cartridge is available for the advanced programmer. PILOT, extended BASIC and Pascal will be available in 1981. • Small Business Accounting General Ledger. Accounts Receivable. Accounts Payable. Inventory Control. Order Entry. ADD IT UP FOR YOURSELF Compare the Atari to any personal computer in its price range. Compare built-in features. Compare expand ability. Compare peripherals and accessories. Compare program- ming and formats (ROM pare i A business, ask your Atari retailer about the Atari Accountant,™ the complete, computerized account- ing system for small businesses. At Atari we're building computer AyA j^l"" systems you won't outgrow. PERSONAL COMPUTERS 1265 Borregas Avenue, Sunnyvale, CA 94086 Call toll-free (800)538-8547 (Except Alaska and Hawaii) (In California: (800)672-1404) for the name of your nearest Atari retailer. Copyright © ;i960 by Steven A Clarcla. All rights reserved. Build a Low-Cost, Remote Data-Entry Terminal Steve Ciarda POB 582 Glastonbury CT 06033 Remote data-entry terminals are not something new. They are devices which provide a means of direct, specialized communication with a computer. In July's Circuit Cellar I said that a pushbutton switch on the end of a long cable is probably the least expensive and most secure form of remote data entry. This is still true, but now it is time to look at more sophisticated forms of remote data entry. There is no formal definition of what constitutes a remote data-entry terminal. The application defines the classification. While a regular video- display terminal can be used for data entry, remote data-entry terminals are usually specially fabricated to fit the application and environment. Remote data-entry terminals almost always communicate in duplex mode, and are capable of displaying com- puter directives to the operator as well as sending operator input to the computer. A further refinement is that the buttons on the panel frequently have function/numeric nomenclature rather than the character set we nor- mally associate with keyboards. A key bearing the label "START" may in fact transmit an ASCII (American Standard Code for Information Inter- change) "A!' when pressed. Applica- tion software running on the control computer is used to recognize that a letter "A" means "initiate the process." The transmission length and protocol should be preset to reduce operator error and entry-panel complexity. Remote data-entry terminals are usually specially fabricated to fit the application and the environment. For example, an entry terminal as- sociated with a dip-plating line in a factory would probably have a panel with a numeric keypad and function buttons labeled "Bath 1", "Bath 2", "Anode Current", "Voltage", 'Time", and 'Temperature". If the operator has to set the anode current in the plating tank, he presses the "Anode Current" button and then enters a four-digit value on the numeric key- pad. When the control computer de- tects the anode-current function but- ton being pressed, it reads the next four characters as numeric informa- tion pertaining to the anode-current function. Other function keys could have entirely different entry sequences. To minimize error, most industrial data-entry terminals rely on con- siderable handshaking. At the very least, they include an accept/reject in- dicator for the operator. If the numeric portion of the anode-current entry did not fit within the limits prescribed for the process, a reject signal must be given to the operator so the data can be reentered. In the more sophisticated units, the data-entry panel often incorporates an alphanumeric display. Usually, it is unnecessary to display textual material to the operator, and these 26 September 1980 © BYTE Publications Inc THE UNBEATABLE S-100 MEMORY i^.jP5lL P^, That's the MEASUREMENT systems & con- trols DMB Series of S-100 bus memory modules, fully compatible with ALPHA MICRO, CROMEMCO, NORTH STAR, MP/M, and most other S-100 systems. Definitely a winner, the DMB Series is avail- able with Bank Select (DMB6400) or without (DM6400) and utilizes industrial quality con- struction, provides outstanding reliability, and is backed by dedicated customer service and a one year guarantee. The DMB6400 uses I/O port addressing for the bank select feature. A switch provides the ability to select any one of the 256 I/O ports for addressing the memory banks. The mem- ory is configured as four totally independent 16K software selectable banks, with each bank addressable on any 16K boundary. Systems Group A Division of MEASUREMENT systems &^ controls incorporated Outstanding features such as those listed below make the DMB series the UNBEATABLE S-100 Memory. • Four independent 16K software select- able banks. • Each bank is independently addressable on any 16K boundary. • Switch selectable bank sizes — from 16K to 64K in 16K increments. • Eight banks (512K) per I/O port for each of the 256 ports. • Z-80 4MHz operation with no wait states using transparent refresh. • On-board diagnostic LED's. • Low power — 8 watts maximum. • Reliable, tested and burned-in memory. • IEEE S-100 compatible timing. • One year guarantee. • Attractive Dealer & OEM Prices. See your nearest computer dealer, or contact us for the complete story on the UNBEAT- ABLE S-100 Memory. 867 North Main St. / Orange, Calif. 92668 / (714) 633-4460 TWX/TELEX: 678 401 TAB IRIN ^ 1 Photo 1: Deluxe remote data-entry terminals, intended for industrial use, often contain specialized equipment to read card-badges, or control unusual functions. Many are con- structed with a hazardous environment in mind, and are waterproof or blast-proof. This particular unit is a function/ numeric panel (FNP) manufactured by General Digital Corporation in East Hartford CT. displays are generally limited to a single line of sixteen to eighty characters. Gas-plasma displays or alphanumeric LED (light-emitting diode) matrices work well and are cost-effective in these applications. Since the panel can communicate in both directions, it is possible for the operator to interrogate the process data base in the computer for specific information. Pressing the "Bath 1" and 'Temperature" buttons could result in the appearance of "#1 TEMP = 192 C" on the sixteen-character display for example. The entire remote data- entry terminal can be constructed with only two integrated circuits. Entry Panels for Personal Computers Deluxe industrial data-entry ter- minals include numeric keypads, function buttons, badge readers for operator identification, Hollerith- card readers for part identification, alphanumeric displays, and elaborate self-test features. A typical unit is 28 September 1980 © BYTE-Publications Inc shown in photo 1. They can be made waterproof, blast-proof, and idiot- proof as required by the application. These are hardly attributes that sug- gest their use in the home. However, the concept of remote data-entry panels connected to a personal com- puter is not as alien as it once seemed. In the past few months I have been presenting articles on various aspects of home control. If you have attached any control devices to your computer and have it controlling the lights and appliances around your home, you undoubtedly are using a program which manipulates logic outputs based on time, status of input sen- sors, and operator commands. What you have is in fact a practical, even if rudimentary, process-control system. It has fundamental similarities to the dip-plating system previously discussed. There seems to be considerable in- terest in home control these days. Many new systems and peripheral devices have been introduced to meet the demand. In my opinion, how- ever, they address only half the prob- lem. They all seem to be limited to central-system use with no facility for remote data entry or effective human engineering. The handheld remote-control devices I detailed in my July article Circle 15 on inquiry card. NEW FROM QT Disk Cabinet for Single 8'' Drive STOCK mi + 110V to 125V or 200V to 250V + 50 or 60 HZ + Data Cable + Fan + Accepts PerscI, Shugart, Siemans, Remex DDC-8+ $250.00 APPLE CLOCK CALENDAR+ lAVAIL, SEPTJ + Day month year + Day of week + 2400 hour time or 12 hour AM PM (selectable) + Leap year + Interrupt timer 4 interval: 1024 Hz (approx 1 millisec), 1 sec, 1 min, 1 hour + On board backup battery + Simple setting of time and date + Simple software interface + Time advance protection while reading Bare Board (with manual) $45.00 Kit $100.00 Assembled & Tested $150.00 I RAM 16+ [STOCKl + Addressable in 4K steps by easily accessible DIP switch. + Memory protection in IK increments defined by an easily accessible DIP switch. Protection may be from the bottom board address up or from the top down. + May deactivate up to six IK segments of the board to create \'holes" for other devices. J Accomplished with jumpers. + Wait states I selected by DIP switch. + 8 bank select lines provided for expansion into Vz million byte systems. + All data, address, and control lines Input buffered. + Ignores I/O commands at board address, + Assembled, tested, and bumed-in at factory. + 1 .3 A typical current consumption. Bare Board $ 20.00 4 MHZ Kit $180.00 2 MHZ Kit $160.00 4MHZA&T $210.00 2 MHZ A&T $190.00 S-100 (SMART) PROTO BOARD+ [STOCK] \ + Wire Wrap or Solder Sockets + Accepts All Standard Sockets (.30" & .60" CTR) + Allows Grid Distributed Power + 3 Voltage Regulators + Kluge Area tor Discretes, Extemal Dnves + 2 Bus Bars for ± Voftapes (Intemal & External) + Accepte Standfard Edge Connector on .1" CTR + Kit Includes 3 Reg/3 Heat Sinks/ Filter Caps/2 Bus Bars/Manual Bare Board $30.00 Kit $50.00 LOOK TO FOR THE EXPANDABLE + DYNAMIC MEMORY (16K to 64K) STOCK + Works with the following Z-80 CPU Boards: Cromemco Systems. S.D, Systems, SSM (CB2A), Jade (Big Z), Q.T. (Z+80) and many others + Uses 3242 Refresh Chip with delay line + Four layer PC Board insures a quiet board + Supports 16K. 32K. 48K or 64K of memory + 24 Address lines per IEEE specifications + Optional M1 Wait state allows error-free operation with faster processors + Optional PHANTOM disable + Uses Z-80 Refresh signal + Bank on/off signal selected by I/O port 40 (Hex) per industry standard. + Bank in use determined by convenient DIP switch selection of data bus bits. + Low power consumption - 5 watts. + Convenient LED indication of bank in use Typical access time of board - (1) using (41t6-200ns) f4Mhz) 240ns - (2) usinQ {4116-150ns) (6Mhz) 200ns Bare Board $ 50.00 16K Kit $280.00 16K A&T $325.00 32K Kit $360.00 32K A&T $420.00 48K Kit $440.00 48K A&T $500.00 64K Kit $510.00 64K A&T $570.00 Bare Board $ 45.00 Kit $190.00 A&T $280.00 1K Memory Kit $ 12.00 Z+80 CPU REV E AVAILABLE SEPTEMBER + IK Ram On Board + 2 Programmable Timers + Power On Jump to On-Board 1K.2K or 4K EPROM (2708-2716-2732) Can be Addressed on any IK or 2K boundary + Parallel I/O Port -i- Programmable Baud Rate Selection (110 to 9600) + On-Board EPROM May be Used in Shadow Mode, Allowing Full 64K RAM to be Used + On-Board USART for Synchronous or Asynchronous RS-232 Operation (Serial I/O Port) CLOCK CALENDAR + -I- Time of Day in Hours. Minutes and Seconds -i- 24 Hour Time Format Bare Board $ 45.00 + Month and Day Date Function + Simple Read Instructions Allow Simple Kit $100.00 Interface to Basic. CPM. Etc. + Will Run With 4MHZ Processors a&T $150 00 + Can be Located at any Group of 4 I/O Port Addressed -t On Board Battery Back-up STOCK 1/0 + 1^ I + Two Independent SYNC/ASYNC Serial Ports + One Strobed Eight Bit Bare Board Parallel Input Port With Handshaking + Three Eight Bit Parallel Ports Kit (Undedicated, User Configured) -i- Three Independent Sixteen Bit Timers f^^r + Eight Level Priority Interrupt Controller + Large Prototyping area has regulated -I-5VDC, -I-12VDC.-12VDC -i- Two software programmable baud rate generators with crystal controlled frequencies (±.01%) $ 69.00 $275.00 $375.00 SILENCE + MOTHER BOARDS -I- No Need for Termination + Very High Crosstalk Rejection -i- LED Power Indicator -(- Fits in Most Mainframes -i- 6, 12 and 18 Slots Available + Has Operated to 14 MHZ Quietly Bare Board Kit A&T 6-SLOT $24.95 $39.95 $49.95 Bare Board Kit A&T 12-SLOT $29.95 $69.95 $89.95 Bare Board Kit A&T 18-SLOT $ 49.95 $ 99.95 $139.95 I QT MAINFRAME + MF + Includes cabinet, 30 amp power supply, and the IEEE S-100 motherboard(12 or 18-sIot). The QT MF-h is fan-cooled, has AC line filter to eliminate EMI, and is fully-assembled and factory- tested. Power and reset switches are located on front panel. MF-h12 $450.00 MF-h18 $500.00 MF-h Without Mother Board $350.00 ISTOCKI MF+MD Includes cabinet, 18 amp power supply, IEEE S-100 Motherboard (6-12-slot) and dual-mini- disk jprovision with disk drive power supply. The (JT MF-i- MD is fan-cooled, has AC line filter to eliminate EMI, and is fuliy-assembled and factory-tested. Power and reset switches are located on the front panel. MF-hMD12 $500.00 MF-hMD6 $450.00 MF-hMD Without Mother Board $450.00 (Accepts 2 each 574" Disk Drives) STOCK QT SYSTEM + -I- Main frame W/P.S. and fan -i- Televideo #920B Terminal + CPU - Z80 - 4MHZ -h 2-8" Disk Drives (801R Shugart) + Floppy Disk Controller (Double Density) + Dynamic Memory M8K - Expandable to ^K) + 2K Monitor Program and Disk Bios on 2716 EPROM + RAM/ROM/PROfUI. uptoSKinany combination on CPU + Hard Disk Compatible + 2 Serial/2 Parallel Ports + Real Time Clock + EPROM Programmer + CPM, 2.2 or 1.4 Operating System -i- MPM Compatible -i- Full line of business software available SYSTEM +SS $4500.00 (DBL DEN SINGLE SIDED) SYSTEM-hDS $5500.00 (DBL DEN DUAL SIDED) STOCK QT TECHNICAL HOTLINE r^^ (213) 973-2619 ^ I WARRANTY - 1 YEAR AGAINST DEFECTS IN MATERIAL AND I J WORKMANSHIP FROM DATE OF SHIPMENT ON ALL QT PRODUCTS quick & TWELr' COMPCTER SYSTEMS INC. 15335 South Hawthome Boulevard Lawndale, California 90260 (213) 970-0952. 800/421-5150 (Continental U.S. Only) (Except Calif.) Dealer Inquiries Invited =1 ^ * ■■^^'^mh. Circle 16 on inquiry card. GET IT OFF THE FLOOR Now that you have a shiny new connputer terminal, what are you going to put it on? Computer Furni- ture and Accessories makes a variety of furniture for a wide range of com- puter applications. In combinations of six widths, three depths, and three heights. With ''L" shaped returns, Micro shelves, data shelves, RETMA mounting, and printer stands. With optional drawers, doors, CRT turn- tables, and casters. Sizes, shapes and colors designed to fit your office or computer room environment. Rea- sonably priced and shipped from stock. Call CF&A. We'll get your system up where you can really put it to use. CP'A Computer Furniture and Accessories, inc. 1441 West 132nd Street Gardena, CA 90249 (213)327-7710 Photo 2: The remote data-entry terminal. Using a new serial keyboard-interface in- tegrated circuit, construction is simple and inexpensive. were only one part of the solution. They facilitate operator feedback, to a limited degree, but like any transmit-only wireless device, they cannot be relied upon in critical ap- plications. Consistent success in con- trol can be obtained only with closed- loop communications hard-wired directly between the operator and the control computer. If you press a but- ton on the entry panel, the computer signifies acceptance of the command by flashing an LED or displaying "HEY, GOOD BUDDY." The easiest way to satisfy the re- quirements of direct communication is to use a standard video-display ter- minal at each remote location. The environment in the average home is not as hazardous as a factory plating line. With video terminals at $700 each, it is at least worth thinking about. Limitations of Video Terminals However, one problem is that most video-display terminals have an RS- 232C serial output which is not sup- posed to be used for communication line lengths over 50 feet. Before you throw out the terminal you were saving to put in the bedroom at the end of the hall (51 feet from the com- puter), I should point out that this specified limitation becomes signifi- cant only at a data rate of 19,200 bps (bits per second). At 300 bps, the problem is of less concern. I have personally driven 1000 feet of transmission line at 300 bps through an RS-232C port. This is a little un- orthodox so don't tell anyone I told you. There are many computer owners like me who don't particularly care to put a $700 terminal in the garage. If your garage is anything like mine, you'd either have to keep it wrapped in plastic or periodically wipe the oil off, and dump the leaves and the dirt out of it. The average open-chassis video terminal would last about a week. Terminals specifically designed for these extremes would be very expensive and probably come in NEM A 4 or NEM A 10 (National Elec- trical Manufacturers Association specifications) oil- and water-tight enclosures. Build a Lov^-Cost Data-Entry Terminal The personal computer applica- tions which would warrant using a $5000 submersible data-entry panel are limited in number. I prefer instead to build something that is less expen- sive. A remote-entry panel, in the garage for instance, might only re- quire functions such as lights on and off, alarm on and off, and maybe a few heating-system functions. A unit installed in the bedroom might have a couple additional functions. For my own use, I felt I could be satisfied with a combination of ten numeric digit codes (0 thru 9) and ten function inputs. Control-system response could be handled adequately with an 8-bit display. Proper choice of components used in construction (with regard to temperature and voltage ranges, etc) would allow use of the panel in a slightly heated garage as well as the bedroom, and make it inexpensive enough to almost be considered disposable. Thanks to a new serial keyboard- interface integrated circuit from Na- tional Semiconductor, the entire remote data-entry terminal, shown in photo 2, can be constructed with only two integrated circuits. The entry panel, which communicates with the host computer in standard 1200 bps serial format, can be placed as far away as 2 miles from the control computer with the addition of a line driver and receiver. With the excep- tion of the hexadecimal display shown on the prototype, the entire 30 Seplember 1980 © BYTE Publications Inc Circle 17 on inquiry card. 26MEGABYTES $4995. I. Suddenly, S-100 microcomputer systems can easily handle 100 million bytes. Because Morrow Designs™ now offers the first 26 megabyte hard disk memory for S-100 systems-the DISCUS M26™ Hard Disk System, It has 26 megabytes of useable memory (29 megabytes unformatted). And ifs expandable to 104 megabytes. The DISCUS M26™ system is delivered complete- a 26 megabyte hard disk drive, controller, cables and operating system-for just $4995. Up to three additional drives can be added, $4495 apiece. The DISCUS M26™ system features the Shugart SA4008 Winchester-type sealed media hard disk drive, in a handsome metal cabinet with fan and power supply. The single-board S-100 controller incorporates intelli- gence to supervise all data transfers, communicating with the CPU via ^ three I/O ports (command, status, and data). The controller has the ability to generate interrupts at the completion of each command to increase system throughput. There is a 512 byte sector buffer on-board. And each sector can be individually write-protected for data base security The operating system furnished with DISCUS M26™ systems is the widely accepted CP/M* 2.0. See the biggest, most cost-efficient memory ever intro- duced for S-100 systems, now at your local computer shop. If unavailable ; locally, write Morrow Designs,™ 5221 Central Avenue, Richmond, CA94804i Or call (415) 524-2101, weekdays 10-5 Pacific Time. *CP/M is a trademark of Digital Researcti. i Q /VIORROIV DESIGNS™ Thinker Toys J terminal can be built for under $50. The heart of my entry panel is the MM57499 serial keyboard-encoder circuit. This device bears some similarity to other scanning keyboard-encoder read-only memories sold by many manufac- turers. It scans a 12 by 8 key matrix and produces the ASCII code for each key. However, using an inexpensive color-burst (3.579 MHz) crystal and an internal data-rate generator, it transmits the characters serially at 1200 bps. In addition, it has the capability to receive serial data (1200 bps) as well. This information can be displayed 1 byte at a time using a single 8-bit shift register. The com- munications protocol in either case is fixed at 1 start bit, 8 data bits, 1 stop Photo 3: It is amazing what can be done with so few parts. Most of the components shown here are quite common and easily available. The use of such materials as a color- burst crystal and a standard hexadecimal keypad make this project reliable and nearly bulletproof. ' V*»«il Photo 4: This twenty-eight-pin integrated circuit keeps things simple by performing the keyboard encoding and transmitting resulting data serially. It also takes care of display functions, with the addition, in figure 2a, of a single shift register. bit, and no parity bit. The data rate can be changed by selecting a dif- ferent crystal or injecting a TTL (transistor-transistor logic )-level clock signal into pin 2 of the MM57499. A block diagram of the interface is shown in figure 1, and the schematic diagram is illustrated in figure 2. The keyboard I used is a standard twenty- key hexadecimal pad. The keys are individually connected across the X and Y matrix inputs as shown. When the A key is pressed, it will short Ys and Xi together sending out the ASCII code for lowercase "a". Press- ing the shift key and the A key together will send an uppercase "A". The ten letters A thru E and a thru e constitute our primary function keys. The numeric-digit keys thru 9 are wired into the matrix in a similar manner. Pressing the shift key and a digit can provide ten more ASCII symbols as function indicators if needed. The key codes corresponding to the cross points of the matrix are outlined in figure 3. To change a par- ticular key, simply determine which scan and strobe lines produce the desired code and wire the key be- tween those points. Three keys, F, H, and L in my unit, are given operations that are different from what their nomenclature might indicate. The F key is wired as a semicolon ";", the L key is wired as a Control "CTL" key and, the H key is now an Escape "ESC". These three keys facilitate using the program- mable phrase feature of the MM57499. During normal use, pressing the A key will send an "a". This could be interpreted by the host computer as the set-alarm signal to the home security system. To reduce potential problems, a numeric code or pass- word could be required with all en- tries. Fortunately, frequent transmis- sion of a lengthy password is not a problem. The MM57499 contains a fourteen- character programmable memory. Pressing a Control-Escape enables this function and automatically transmits a hexadecimal FA to tell the control computer that the panel is in the program mode. The next one to fourteen keystrokes (character or control) will be stored in memory. To halt the entry process, for instance after entering a password of "abAB", we just type a Control-semicolon. This will transmit the stored message 32 September 1980 © BYTE Publications Inc Circle 18 on inquiry card. OOMPUSIAR INTERTEC'S NEW $2500 MULTI-USER SMALL BUSINESS COMPUTER At last, there's a multi-user micro- computer system designed and built the way it should be. The CompuStar^. Our new, low-cost "shared-disk" multi-user system with mainframe performance. Unlike any other system, our new CompuStar of fers what we bel ieve to be the most practical approach to almost any multi-user application. Data entry. Distrib- uted processing. Small business. Scientific. Whatever! And never before has such powerful performance been available at such modest cost. Here's how we did it . . . The system architecture of the CompuStar is based on four types of video display terminals, each of which can be connected into an auxiliary hard disk stor- age system. Up to 255 terminals can be connected into a single network! Each ter- minal (called a Video Processing Unit) con- tains its own microprocessor and 64K of dynamic RAM. The result? Lightning fast program execution! Even when all users are on-line performing different tasks! A special "multiplexor" in the CompuStar Disk Storage System ties all exter- nal users together to "share" the system's disk resources; So, no single user ever need wait on an- other. An exciting concept .. . with some awesome application possibilities! CompuStar^^ user stations can be configured in almost as many ways as you can imagine. The wide variety of terminals offered gives you the flexibility and versatility you've always wanted (but never had) in a multi-user system. The CompuStar Model 10 is a program- mable, intelligent terminal with 64K of RAM. It's a real workhorse if your re- quirement is a data entry or inquiry/response application. And if your terminal needs are more sophisticated, select either the CompuStar Model 20, 30 or 40. Each can be used as either a stand- alone workstation or tied into a multi-user network. The Model 20 incorporates all of the features of the Model 10 with the addition of two, double-density mini-flop- pies built right in. And it boasts over 350,000 bytes of local, off-line user stor- age. The Model 30 also features a dual drive system but offers over 700,000 bytes of disk storage. And, the Model 40 boasts nearly Vk million bytes of dual disk stor- age. But no matter which model you select, you'll enjoy unparalleled versatility in configuring your multi-user network. Add as many terminals as you like - at prices starting at less than $2500. Now that's truly incredible! No matter what your application, the CompuStar can handle it! Three disk storage options are available. A tabletop 1 megabyte 8" winchester-type drive complete with power supply and our spe- cial controller and multiplexor costs just $3995. Or, if your disk storage needs are more demanding, select either a 32 or 96 megabyte Control Data CMD drive with a 16 megabyte removable, top loading car- tridge. Plus, there's no fuss in getting a CompuStar system up and running, dust plug in a Video Processing Unit and you're ready to go . . . with up to 254 more ter- minals in the network by simply connect- ing them together in a "daisy-chain" fashion. CompuStar's special parallel interface allows for system cable lengths of up to one mile . . . with data transfer rates of 1.6 million BPS! Software costs are low, too. CompuStar's disk operating system is the industry standard CP/M* With an impressive array of application soft- ware already available and several communication packages offered, the CompuStar can tackle even your most difficult programming tasks. Compare for yourself. Of all the microcomputer-based multi- user systems available today, we know of only one which offers exactly what you need and should expect. Excep- tional value and upward growth capability. The CompuStar^^. A true price and performance leader! il ilNTE^TEC ,DATA :SYSrEMS^ 2300 Broad River Rd ColumOia. X 29210 (803) 798-9100 TWX; 810-666-2115 Eiiir\ •flegisteied uadematk ol D(giiat Reseaicti Ire A RESPONSE AND STATUS LED DISPLAY n SHIFT REGISTER POWER ON RESET OPERATOR DATA CL OCK ENTRY MM57499 SERIAL KEYBOARD INTERFACE KEYBOARD 20-KEY KEYBOARD SERIAL OUT LlllE DRIVER Xo -X7 A ^ SERIAL m LINE RECEIVER Y5- Yll \ > MHz AL i 3.578 -- CRYST 1200 BPS ) UP TO 2 MILES OF TRANSMISSION LINE Figure 1: Block diagram of a minimal-component remote-entry panel, capable of serial communication with most host computers. to the computer. The first time it is transmitted, a hexadecimal F9 is af- fixed to the beginning of the message to tell the computer that the terminal is no longer in the programming mode. At any time after this point, whenever a Control-semicolon is pressed, the stored password will be transmitted. Reprogramming this phrase is accomplished by simply pressing Control-Escape again and repeating the sequence. Receiving data from the control computer in response to an operator input is where the real power of this interface becomes apparent. The computer can signify the acceptance or rejection of a command input, or the completion of a task by turning on one of the LEDs connected to IC2. Text continued on page 42 A significant development in tiand tool design. Engineered witti traditional VISE-GRIP quality. Introducing the new VISE-GRIP long nose lockin g pliers. (Model 6LN. with wire-cutter, pictured actual size.) VISEGRII? © 1980 Petersen Mfg. Co., Inc. 34 Seplember 1980 © BYTE Publications Inc Circle 19 on inquiry card. Circle 20 on inquiry card. Multi-User UniFLEX is the first full capability multi-user operatirig system available for microprocessors. Designed for the 6809 and 68000, it offers its users a very friendly computing environment. After a user 'logs-in' with his user name and password, any of the system programs may be run at will. One user may run the text editor while another runs BASIC and still another runs the C compiler. Each user operates in his own system environment, unaware of other user activity. The total number of users is only restricted by the resources and efficiency of the hardware in use. The design of UnlFLEX, with its hierarchical file system and device independent I/O, allows the creation of a variety of complex support programs. There is currently a wide variety of software available and under development. Included in this list is a Text Processing System for word processing functions, BASIC interpreter and precompiler for general programming and educational use, native C and Pascal compilers for more advanced programming, sort/merge for business applications, and a variety ofdebug packages. The standard system includes a text editor, assembler, and about forty utility programs. UniFLEX for 6809 is sold with a single CPU license and one years maintenance for $450.00. Additional yearly maintenance is available for $100.00. OEM licenses are also available. FLEX TM Multi-Tasking UniFLEX is a true multi-tasking operating system. Not only may several users run different programs, but one user may run several programs at a time. For example, a compilation of one file could be initiated while simultaneously making changes to another file using the text editor. New tasks are generated in the system by the 'fork' operation. Tasks may be run in the background or 'locked' in main memory to assist critical response times. Inter- task communication is also supported through the 'pipe' mechanism. UniFLEX is offered for the advanced microprocessor systems. FLEX, the industry standard for 6800 and 6809 systems, is offered for smaller, single user systems. A full line of FLEX support software and OEM licenses ore also available. Box 2570, West Lafayette, IN 47906 (317)463-2502 Telex 276143 '"^UniFLEX and FLEX ore trademarks of Technical Systems Consultants, Inc. b P c^ ■■■■■ b if ./ #/ / ,? s ENTERPRISES INCORPORATED 2951 W. Fairmount Avenue • Phoenix, AZ 85017 • (602)265-7564 Please note new address 36 September 1980 © BYTE Publications Inc Circle 21 on inquiry card. Circle 22 on inquiry card. ALTOS COMPUTER SYSTEMS PROUDLY ANNOUNCES AO8000-6 • ■ COMPUTER SYSTEMS ^^^H ^ ^mmmmm THE VERY FIRST Double Density Z80 Micro-Computer plus Twin 8" Floppies plus !4.5Mb Winchester Disk for under $9,500! And more! 4 user CP/M® for .under $12,000! SCP/M JS a registered trademark of Digital Research, Inc, ALTOS COMPUTER SYSTEMS, LEADER IN SINGLEBOARD TECHNOLOGY DOES IT AGAIN WITH ITS SINGLEBOARD ACS8000-6- TOTAL BUSINESS COMPUTER' HIGH TECHNOLOGY AGAIN WINCHESTER MASS STORAGE The new ACS8000-6 single board computer is packed with ultra-high technology: Z80 double-density computer, up to 208Kb of high speed RAM, Floppy-disk and Win- chester Hard Disk controllers, DMA, up to 6 serial/2 Parallel I/O, optional 32 bit floating point processor . . . AH on One Board, ftjlly socketed, fully doc umented reliable and maintainable. We're staying with Shugart for both floppies and Winchester hard disk. Why? Simple, low price, solid reliability and they're our next door neiglibor. Our single board computer supports up to 4 Mbytes of floppies and 58 Mbytes of Winchester mnning under AMEX. ADVANCED MULTI-USER SOFTWARE Our new ALTOS Multi-User Executive (/WIEX) supports four independent CP/M compatible programs in any of six languages: Basic, Fortran, Cobol, Pascal, APL, C, and a wealth of complete business application packages. COMPUTER SYSTEMS 2360 Bering Drive San Jose, CA 95131 MINI PERFORMANCE FOR 1/2 COST Prices you will love. Entry levei ACS8000-6 Hard Disk System $9,450 2 users $10,670. 4 users $11,960, AMEX separate at $250. AVAILABLE NOW! Call for your nearest Altos dealer. (408) 946-6700. Telex 171562 ALTOS SNTA. 8 BIT STATUS DISPLAY MSB __\^^_^ 6 |lO |ll 47ft TYPICAL FOR 8 TIL-209A LED TYPICAL FOR 8 Number Type + 5V GND IC1 MM57499 11 1 IC2 74164 14 7 IC3 75114 16 8 IC4 75115 16 8 IC5 75115 16 8 IC6 75114 16 8 I-5V Qa Qb Qc Qd Qe Qf Qg Qh CLEAR CLOCK IC2 74164 8 BIT SHIFT REGISTER DATA 8 CLOCK 18 1N914 >39K . ■ 10;iF ' lOV + 5V .lOK 24 r-^ SERIAL ""•— ^OUT ^.^-^ SERIAL "^■— J IN TO FIGURE 2B ICl MM57499 RESET X2 Xi TRANSMIT RECEIVE Yn Yo Y7 Y, CRYSTAL 11 ^8 ^7 ^6 ^5 CRYSTAL >^SHIFT •^^( 10 K lOK !i CTL •V S.V 22 1 21 iL il Al A "X xx 25 NV 'V X 26 X 5S.V^\V^ V •V X 28 1N914 TYPICAL FOR 10 20 •Y ►\^3 ^^\^2 s,^i ^^y -V 10 K ESC >1M IK ; 3.578MH2 ■ CRYSTAL : 27pF m Figure 2a: Schematic of the remote data-entry terminal Use of the MM57499 serial keyboard-interface circuit allows for simple con- struction. Data is entered via a standard keypad, and encoded by the interface circuit. Data may then be sent serially at 1200 bps to the computer over any of a number of types of transmission line. In this circuit, all diodes are lN914s, and not all Yn lines are used since a hexadecimal keypad does not require them. Holding any key down causes a 15-cps automatic repeat. UCSD* System for TRS-80 Model 11+ The most portable operating system now supports FORTRAN. Pascal and/or FORTRAN modules are compiled in universal P-code, so they can run on most microprocessors, of ten without recompiling. Programs execute up to 10 times f asterthan comparable BASIC programs, and use much less memory. Ready to run on TRS-80 Model II {64K). FEATURES PLUS, from PCD Systems I Interactive operating system-dynamic overlays, disk file handling, run-time sup- port and block I/O routines. ' Fast, one pass compilers. I Two Editors— one screen oriented for pro- gramming and text editing, one character oriented for hard copy terminals. ■ File handler to manipulate disk files. ■ Macro-assembler that produces code for linking with Pascal or Fortran programs. ■ Linker for link-editing of object and as- sembly code modules. ■ Library of program modules and utilities. I Disk formatting program to initialize dis- kettes in single or double density formats. ■ Configuration program for serial I/O. ■ Disk-set program to permit separate as- signment of density and format charac- teristics for each disk drive. DOCUMENTATION ■ UCSD System Manual (400 pages). ■ Beginner's Guide To UCSD Pascal. ■ Pascal User Manual & Report. ■ Fortran User's Manual with systems. Fortran PCD Systems, Inc. P O Box 1 43 Penn Yan, NY 1 4527 31 5-536-3734 PRICES ■ UCSD System with Pascal Compiler $350 with Pascal and Fortran Compilers $500 ■ Fortran Compiler alone (requires Version II.O) $200 ■ P-Code Interpreter alone (either LSI-11 orZ-80) $ 85 Optional Utility Programs ■ CP/M* to Pascal file conversion $ 50 ■ TRSDOS+ to Pascal file conversion $ 50 ■ Z-80 Disassembler/Dump program $ 50 ALSO AVAILABLE ■ UCSD System for M1NC« or PDT^. ■ Z-80 Adaptable System (you write BIOS). ■ UCSD System for CP/M environments. PCD Systems is a licensed distributor of the UCSD System for Pascal and Fortran. Dealer inquiries are invited. *Trademark of the Regents of the University of California ^Trademark of Tandy Corporation *Trademark of Digital Research ^Trademark ot Digital E«|uipment Corporation 38 September 1980 © BYTE Publications Inc Circle 23 on inquiry card. V ^ Solve your personal energy crisis. Let VisiCalc " Software do the work. With a calculator, pencil and paper you can spend hours plan- ning, projecting, writing, estimating, calculating, revising, erasing and recalculating as you work toward a decision. Or with the Personal Software"* VisiCalc program and your Apple* II you can explore many more options with a fraction of the time and effort youVe spent before. VisiCalc is a new breed of problem-solving software. Unlike prepackaged software that forces you into a computerized straight jacket, VisiCalc adapts itself to any numerical problem you have. You enter numbers, alphabetic titles and formulas on your keyboard. VisiCalc organizes and displays this infor- mation on the screen. You don't have to spend your time programming. Your energy is better spent using the results than get- ting them. Say you're a business manager and want to project your annual sales. Using the calculator, pencil and paper method, you'd lay out 12 months across a sheet and fill in lines and columns of figures on products, outlets, salespeople, etc. You'd ca culate by hand the subtotals and summary figures. Then you'd start revising, erasing and recalculating. With VisiCalc, you simply fill in the same figures on an electronic "sheet of paper" and let the computer do the work, Once your first projection is complete, you're ready to use VisiCalc's unique, powerful recalculation feature. It lets you ask "What if?',' examining new options and planning for contingencies. "What if" sales drop 20 percent in March? Just type in the sales figure. VisiCalc instantly updates all other figures affected by March sales. Circle 24 on inquiry card. Or say you're an engineer working on a design problem and are wondering "What if that oscillation were damped by another 10 percent?" Or you're working on your family's expenses and wonder "What will happen to our entertainment budget if the heating bill goes up 15 percent this winter?" VisiCalc responds instantly to show you all the consequences of any change. Once you see VisiCalc in action, you'll think of many more uses for its power. Ask your dealer for a demonstration and dis- cover how VisiCalc can help you in your professional work and personal life. You might find that VisiCalc alone is reason enough to own a personal computer. VisiCalc is available now for Apple II computers with versions for other personal computers coming soon. The Apple II version requires a 32k disk system. For the name and address of your nearest VisiCalc dealer, call (408) 745-7841 or write to Personal Software, Inc., 592 Weddell Dr., Sunnyvale, CA 94086. If your favorite dealer doesn't already carry Personal «^^^ Software products, ask him to give us a call. VisiCalc was developed exclusively for Personal Software by Software Arts, Inc., Cambridge, Mass. TM— VisiCalc is a trademark of Personal Software, Inc. * Apple is a registered trademark of Apple Computer, Inc. REMOTE ENTRY PANEL COMPUTER IC 1 P I N 9 SERIAL DATA INPUT TO FIGURE 2A -' SERIAL DATA OUTPUT FROM FIGURE 2A Figure 2b: Transmission-line drivers for the terminal are capable of transmitting over 10,000 feet of 100-ohm line. The capacitors at pin 4 of IC4 and IC5 help to reduce noise pick-up by decreasing the frequency response of the receiver. .TEtlPERt^TLiRE AND SmLES x,y Genesis Applesoft subroutines add graphics to your programs. From FUTUREWORLD 2514 University Drive Durham, NC 27707 Dept (919) 489-7486 40 September 1980 © BYTE Publications Inc x,y Genesis now has: • ability to dump graphics screen to printers, • standard format graphs (pie chart, bar chart, scatter plot, line plot). Interfaces to popular file management systems under development. B9 $74.95 Circle 25 on Inquiry card. New additions to our select software list: VISICALC™ $150.00 A product of Software Arts Inc. * VISICALC Models * Save hours of setup time! Visible Bookkeeper $59.95 Nine basic bookkeeping models with explanations for adapting to your own small business. Business Projector $39.95 Basic one year general business projection model with cash flow, ratio analysis and supporting schedules. Circle 26 on inquiry card. ^^ Aflter you've broken the pole vault recordfSee if you can outsmart the kiUer dwarves. TWO incredible games from Microsoft. There are plenty of com- puter games around. But most of them probably won't hold your interest for more than a few hours. That's what makes these two releases from Micro- soft so remarkable. They'll keep challenging you in new ways every time you play. Olympic Decathlon— a real workout! There's never been a program that tests your reflexes and coordination like Olympic Decathlon. Just like the real one, Microsoft's has 10 events, including shot put, pole vault, long jump, javelin throw, and six more. Win-^^^^ ning takes a combination of strategy, j^ timing, coordination, and physical / endurance (really!). / ; When you jump or throw, the pro- / gram calculates the actual trajec- / tory, and shows you what's happen- 7 ing with exciting animated / graphics. After each event, the ' scores of all competitors (up to 8) are displayed. It's the ulti- mate party game to show off j your computer! Disk-based Decathlon ^ runs on a 32k TRS-80. The cassette version requires a 16k Level I or Level II system. ^ TRS-80 is a trademark of Radio Sliack Corp. — ^ Apple 1 1 is a trademark of Apple Computer. Inc. Versions for the Apple II available soon. Adventure— the classic mind game. If you've ever been lucky enough to play Adventure on a big computer, you know how addictive it is. Fantasy, deduction, and magic all come into play as you explore the chambers of Colossal Cave, collect- ing treasure while avoiding pitfalls and hostile crea- tures. There are surprises around every corner, and even veteran players keep discovering new things and improving their scores. Microsoft has the complete microcomputer version of the original FORTRAN Adventure that runs on large timesharing systems. It runs on TRS-80 and Apple II ^^systems with at least 32k memory and one disk. ^ iWicrosof t— a name wortii trusting. m As the world's most experienced producer f of microcomputer software, Microsoft's pol- 1 icy is to offer only the best, most rewarding /programs in existence. After playing Adventure and Olympic Decathlon, we think you'll agree. Visit your computer retailer soon for a real I challenge. Or ten. >tiCRp60fT ^ CONSUMER^ PRODUCTSP 400 108th Ave. N.E.; Suite 200 Believue, WA 98004 (206) 454-1315 , MM57499 1 GND xo 28 2 CRYSTAL CRYSTAL Xl X2 27 3 26 4 RESET X3 25 5 Y4 TRANSMIT OUT 24 6 Y5 X6 23 7 V6 X5 22 8 Y? X4 21 9 DCpCIV/C INPUT Y8 Yll 20 10 Y9 19 11 vcc CLOCK OUT 18 12 Yo DATA OUT (Xy) 17 13 Yl YlO 16 14 Y2 Y3 15 Figure 2c: The MM57499 serial keyboard- encoder integrated circuit, which scans a 12 by 8 matrix and produces the ap- propriate ASCII code for each key. Text continued from page 34: This is accomplished by sending an ASCII character to the entry receiver that has a key code corresponding to the bits we wish to light. These codes are listed in table 1. For example, to light the LSB (least- significant bit) of the display, a hexa- decimal 01 is sent. This corresponds to a "Control-shift-A". The Break key code FF would turn on all the indi- cators. To successfully use these LEDs, a lookup table and bit map should be included in any software driver for the terminal. My prototype included both an 8-bit LED display and a two-digit hexadecimal display. They are wired in parallel and display the same information. Long Distance Transmission No one bothers to construct a remote-entry terminal for placement next to the control computer. In most cases you will not have to resort to extraordinary means to communicate a couple hundred feet. Should you need to communicate long distances, such as 3000 feet to the barn, the line- driver circuitry of figure 2 should be used. It is capable of driving 10,000 feet of 100-ohm transmission line. For short distances it isn't absolutely necessary to use this wire or circuit. A SHIFT KEY CONTROL REPEAT CAP LOCK SHIFT LOCK Z z Y y X X W w V V U u T t S s R r Q q P P N n M m L 1 K K J J 1 i H h G g F f E e D d C c B b A a D p / > = < + * ) 9 ( 8 7 a 6 % 5 4 # 3 2 ! 1 BREAK RTN SP ESC LF 9 8 7 6 5 4 3 2 1 DEL A )■ 1 {' BS ' TAB - - i t FMT IL DC DL FS EOL EOS CLEAR SC B TAB DE ADM IC LS FN7 FN6 FN5 FN4 FN3 FN2 FNl Yll ^10 Y8 Y6 ) SCAN LINES STROBE LINES Figure 3: Key function chart. Although not all scan lines are used for the hexadecimal keypad, the MM57499 circuit is capable of encoding the full ASCII character set. In the unit described, shorting X3 and Y5 produces an ESC (Escape) code, while shorting X5 and Ys gives the code for 5. pair of MC1488 and MC1489 RS- 232C drivers can be substituted for short runs and twisted-pair wiring used instead of 100-ohm cable. The degree of leeway allowed depends upon the electrical noise between the terminal and the computer. If in doubt, use the heavy-duty driver I've outlined. Whether you build this interface or not is immaterial so long as you recognize the advantages it presents for those readers interested in control applications. I've only scratched the surface concerning the capabilities of the MM57499. We could also have used it as a single-chip remote-status transmitter, or we could have ex- panded the receiver section for full message displays. Trying to cover all potential applications is impossible in a single article. I assure you that I am not through with this device, and Til think up a few more gadgets that use it. If in the meantime you have any brainstorms concerning home con- trol, Fd appreciate hearing about them. For information on the MM57499 write to: Mike Van Slack Product Marketing Engineer National Semiconductor 2900 Semiconductor Dr Santa Clara CA 95051 Next Month: We will explore some ways to use LCDs (liquid-crystal displays) . M 42 September 1980 © BYTE Publicalions Inc Circle 27 on inquiry card. If you can type,you can handle your accounting, word processing and much more on ISC's Small Business Computer! The Intecolor^ 8963 is just one of a complete line of ISC desk- top computers designed for businessmen who don't know how- or don't have time- to write programs. It's CP/M® com- patible, so you can choose from hundreds of CP/M business programs- programs that have been proven in hundreds of actual applications. Programs like General Ledger, Accounts Receivable and Payable, Payroll, Mailing List and Inventory Control are now available in color. You'll comprehend data faster, thanks to the proven readability of ISC's eight-color display. To compose letters and other documents quickly and easily, you'll want ISC's unique co/or-coded Word Processing pro- gram. With an optional printer, you can print out as many mistake-free originals as you want! The Iritecolor 8963 gives you all the benefits of color graphics computing at a price that's competitive with black- and-white. It's complete with 19" color graphics display, typewriter-like keyboard, dual disk drive for data storage - even a color version of Microsoft* Business BASIC for those of you who do want to program. Don't let your business get behind the times. Call your ISC sales representative or visit your nearest Factory Authorized ISC dealer and get a "hands on" demonstration today. Color Communicates Better^*^ =<• us domestic price. Unrelouched phoro of screen. CP/M is a registered trademark of Digital Research Corp. OEM Quantity Discounts are available to Qualified Dealers and Volume Users of 25 Systems (or greater) per year. Call your nearest ISC Representative listed below. ISC SALES REPRESENTATIVES: AL: 205/883-8660. AZ: 602/994-5400. AR: (TX) 214/661-9633. CA: Alhambra 213/281-2280, Goleta 805/964-8751. Irvine 714/557-4460. Los Angeles 213/476-1241, Los Altos 415/948-4563, San Diego 714/292-8525, CO: 303/355-2363, CT: 203/624-7800, DE: (PA) 215/542-9876. DC: (VA) 703/569-1502. FL: Ft.Lauderdale305/776-4800, Melbourne 305/723-0766, Orlando 305/425-5505. Tallahassee 904/878-6642, GA: Atlanta 404/455-1035, HI: 808/524-8633. ID: (UT) 801/292-8145, IL: (No.) 312/564-5440. (So. MO) 816/765-3337 IN: (IL) 312/564-5440. lA: (Scott County Only) 312/564-5440. (MO) 816/765-3337 KS: (MO) 816/765-3337. KY: 606/273-3771. LA: 504/626-9701. ME: (MA) 617/729-5770. MD: (VA) 703/569-1502, MA: 617/729-5770. Ml: Brighton 313/227-7067. Grand Rapids 616 393-9839. MN: 612/645-5816, MS: (AL) 205/883-8660. MO: 816/765-3337, MT: (CO) 303'355-2363. NB: (MO) 816 765-3337, NH: (MA) 617/729-5770, NJ:(No.) 201/224-6911. (So.) 215/542-9876. NV: (AZ) 602 994-5400. NM: 505/292-1212. NY: Metro/LI(NJ) 201/224-6911. N. Syracuse 315 699-2651. Fairport 716 223-4490. Ulica 315/732-1801, NC: 919 682-2383. ND: (MN) 612/645-5816. OH: Cleveland 216/398-0506. Dayton 513 435-7684, OK: (TX) 214y661-9633. OR: 503 644-5900. PA: (E) 215 542-9876. (W) 412 922-5110. Rl: (MA) 617 729-5770. SC: 803'798-8070, SD: (MN) 612; 645-5816. TN: 615 482-5761. TX: Austin 512/454-3579. Dallas 214/661-9633. El Paso Area (Las Cruces. NM) 505 524-9693. Houston Only 713 681-0200. UT: 801/292-8145, VT: (MA) 617/729-5770. VA: 703/569-1502. WA: 206/455-9180. WV: (PA) 412/922-51 10. Wl: (IL) 312/564-5440. WY: (CO) 303/355-2363, EUROPEAN EXPORT SALES: EUROPE: (MA) 617/661-9424. BELGIUM: Brussels 02-242-36-04, DENMARK: 02-913255, FRANCE: Rueil Malmaison 749-47-65. Paris 33-1-306-4606, GREECE: Athens 642-1368. ITALY: Milano 02600733, THE NETHERLANDS: Poeldijk 01749-47640, Amsterdam 020-360904, SPAIN: Barcelona 204-17-43. SWEDEN: Vallingby 08-380-370. SWITZERLAND: Mutschellen 057-546-55. UNITED KINGDOM: Bournemouth 0201671181. WEST GERMANY: Koblenz 01 149-31025/6, AUSTRALIA & NEW ZEALAND: Auckland 876-570. Canberra 58-1811, Chermside 59-6436. Christchufch 796-210. Melbourne 03-543-2077. Sydney 02-808-1444, Wellington 644-585, CANADA: Dorval 514/636-9774, Ottawa 613/224-1391. Toronto 416 787-1208, Vancouver 604/684-8625. CENTRAL AND SOUTH AMERICA & CARIBBEAN: (GA) 404 394-9603. MEXICO: Monterrey 564-876, FAR EAST: (CA) 213 382-1107. HONG KONG: 5-742211. JAPAN: (Tokyo) (03) 463-9921. TAIWAN: (Taipei) 02-7026284, MIDDLE EAST: (GA) 404/581-0243, EGYPT: 809933, ISRAEL: Ramat Gan 03725749, KUWAIT: Kuwait 438-180/1/2, LEBANON: Beirut 221731/2601 10, SAUDI ARABIA: Jeddah 27790, Riyadh 25083-39732. For sales and service in other counlries contact ISC headquarters in Norcross, GA , U.S. A intelligent Systems Corp: Intecolor Drive D 225 Technology Park/Atlanta D Norcross, G A 30092 D Telephone 404/449-5961 D TWX 81 0-766-1 581 Your vehicle for com The Challenger 8P DR The general purpose microcomputer was first introduced as a computer for hobbyists and experimenters. However, as the industry has grown, microcomputers have become specialized for personal use or for small business use. There is virtually no computer for the serious experi- menter with one important exception, the Ohio Scientific Challenger 8R The C8P is unique in that it incor- porates the features of state-of-the- art personal computers, with the memory and disk storage capacity of business computers, along with the "mainframe" bus architecture and open ended expansion capability of industrial control computers. Personal Computer Features The CSPDF's specs beat all personal computers hands down. It executes instructions two to three times faster, and displays more alphabetic characters on its screen than other models. It has upper and lower case and graphics in 16 colors. The C8P's standard I/O capabilities are far more extensive than any other com- puter, with joystick and keypad inter- faces, sound output, an 8-bit D/A converter, 16 parallel I/O lines, modem and printer interfaces, AC remote control and security monitor interfaces and a universal acces- sory port that accepts a prom blaster, 12-bit analog I/O module, solderless prototyping board and more. Ohio Scientific offers a large library of personal applications programs, including exciting action games such as Invaders and Star Trek, sports simulations, games of logic and educational games, personal applications such as biorhythms, calorie counter, home programs such as checking and savings account balancers and a home budgeter just to name a few. A new Plot BASIC makes elaborate anima- tions easy, and music composition program allows you to play complex multi-part music through the com- puters DAC. At the systems level the machine comes standard with OS-65D, an ad- vanced disk operating system with Microsoft BASIC and an interactive Assembler Editor. Optional software includes UCSD PASCAL and FORTRAN and an Information Management System (OS-MDMS). Dozens of independent software suppliers now also offer personal programs for the C8P. BSSXSff n IL-I /^ W puter explorations. Business Computer Features The C8P DF utilizes dual 8" floppy disk drives which store up to eight times as much information as per- sonal computer mini-floppies, and an available double-sided option expands capacity to 1.2 megabytes of on-line storage. The C8P DF is compatible with Ohio Scientific's business computer software, in- cluding OS-65U an advanced oper- ating system, and an Information Management System (OS-DMS) with supplementary inventory, account- ing, A/R-A/P, payroll, purchasing, estimation, educational grading and financial modeling packages. The system also supports word process- ing (WP-3) and a fully integrated small business accounting system (OS-AMCAP V1 .6). The C8P D F's standard modem and printer ports accept high-speed matrix printers and word-processing printers directly. Home Control and Industrial Control The C8P DF has the most advanced home monitoring and control capa- bilities ever offered In a computer system. It incorporates a real time clock and a unique FOREGROUND/ BACKGROUND operating system which allows the computer to function with normal BASIC pro- grams, at the same time it is monitoring external devices. The C8P DF comes standard with an AC remote control interface, which allows it to control a wide range of AC appliances and lights remotely, without wiring, and an interface for home security systems which moni- tors fire, intrusion, car theft, water levels and freezer temperature, all without messy wiring. In addition, the C8P DF can accept Ohio Scien- tific's Votrax voice I/O board and/or Ohio Scientific's new universal telephone interface (UTI). The tele- phone interface connects the com- puter to any telephone line. The computer system is able to answer calls, initiate calls and communicate via touch-tone signals, voice outpu t or 300 baud modem signals. It can accept and decode touch-tone signals, 300 baud modem signals and record incoming voice messages. These features collec- tively give the C8P DF capabilities to monitor and control home functions with almost human-like capabilities. For process control applications, a battery back up calendar clock with automatic computer restart capabili- ties Is available. Ohio Scientific's unique accessory ports allow the connection of a nearly unlimited number of 48 line parallel I/O cards and 12-bit high speed instrumenta- tion quality analog I/O modules to the computer by inexpensive 16-pin ribbon cables. Exploring New Frontiers Ohio Scientific's vocalizer software processes normal BASIC print state- ments with conventional spellings and speaks them clearly in real-time on computers equipped with the UTI (CA-15B or CA-14A). This voice out- put capability, combined with the C8P's remote control, remote sens- ing, telephone interface capabilities and reasonable cost open up new frontiers for computer applications. Documentation The C8P DF is not a beginner's com- puter and doesn't come with begin- ner's documentation. However, Ohio Scientific does offer detailed documentation on the computer which is meaningful for experts, including a Howard Sams produced hardware service manual that in- cludes detailed block diagrams, schematics, parts placement dia- grams and parts lists. Ohio Scientific is now also offering fully documented Source Code in machine readable form for OS-65D, the Challenger 8P's operating system allowing experimenters and industrial users to customize the system to their specific applications. What's Next? Ohio Scientific is working on a speech recognizer to complement the UTI system, with a several hun- dred word vocabulary. The company is also developing an 8 megabyte low-cost, add-on hard disk for use in conjunction with natural language parsing to further advance the state- of-the-art in small computers. The modular bus architecture of the C8P assures system owners of being able to make use of these new developments as they become available just as the owner of a 1976 vintage Challenger can directly plug in voice output, the UTI and other current state-of-the-art OSI products. The C8P DF with dual 8" floppies, BASIC and two operating systems costs about $3000, only slightly more than you would pay for a dual mini-floppy equipped personal com- puter with only a fraction of the capabilities of the C8P For more information and the name of the dealer nearest you, call 1-800-321-6850 toll free. 1333 SOUTH CHILLICOTHE ROAD AURORA. OH 44202 • [21 6] 831 -5600 Circle 28 on inquiry card. An 8088 Processor for the S-100 Bus Parti Thomas Woodward Cantrell 2475 Borax Dr Santa Clara CA 95051 The 16-bit microprocessor has definitely arrived. No one doubts that this new wave of high-performance processors will soon be operating on the familiar S-100 bus. In fact, Seattle Computer Products is already ship- ping its Intel 8086-based processor card, along with a support card that includes vectored-interrupt control, hardware mathematical operations, and miscellaneous timer/counters. Godbout Electronics has designed a card containing two microprocessors and the logic allowing transfer of control between them by software. One of the processors on this board is an Intel 8085A-2, which allows the board to be placed in 8080A/8085A/Z80A-based S-100 systems with a minimum amount of hassles. Using various existing or soon-to- be-developed cross-software pro- ducts, programs can be developed for the other processor on the board, the Intel 8088. When the new software is developed and loaded, control can be transferred from one microprocessor circuit to the other for checkout and debugging. This is a novel solution to the problem of bootstrapping a system consisting of both new hard- ware and new software. Microsoft and Digital Research, Photo 1: A wolf in sheep's clothing. The panel may say "8080, " but the processor card in this system is based on Intel's high-performance 8088. both highly renowned producers of quality software, are making their contributions to the processor revolu- tion. Microsoft is already shipping an 8086/8088 version of its popular BASIC interpreter as well as an 8086/8088 cross-macroassembler which runs under Digital Research's CP/M. A disk operating system and other system software are to follow. Digital Research has an 8086/8088 based version of CP/M in the works. Expect this to be followed with new versions of MP/M and PL/I. The multitude of vendors who supply software to run under CP/M should already be converting their software for use with the new CP/M. Problems Remain Be that as it may, the S-lOO/16-bit processor picture is not as bright as it may seem. The fundamental problem is that the S-100 bus was originally designed by MITS (of Altair fame) for the Intel 8080, an 8-bit micro- processor. To "upgrade" the S-100 bus to the higher levels of perfor- mance offered by the new machines, certain problems must be addressed. The IEEE (Institute of Electrical and Electronics Engineers) Standards Committee, through its S-100 bus standard definition, has assured a future for the S-100 bus in two ways. First, the problem of incompatibil- ity between different "S-100" modules will be laid to rest. Woe be unto today's computerist who at- tempts to use a Brand X DMA color video-display board with a Brand Y 46 September 1980 © BYTE Publications Inc Circle 29 on inquiry card. '^ QUALITY THAT'S WHAT SEPARATES THIS PRINTER FROM 1 THETat5 MICROTEK MT-80 SOLID VALUE FOR YOUR DOLLAR The market is flooded with low-cost printers that look and last more like toys. The Microtek MT-80, our versatile alpha- numeric line printer, has a high quality print mechanism that gives you solid value for your dollar. It has been de- signed with a superior brain resulting in more advanced features and more de- pendable performance. Our printer is so reliable that we offer you an incredible 365 days warranty. We stand behind every printer we make because we build quality into each one. So stop tinkering with toys and get serious. Demand 100% value by specifying the MT-80. OUR UNIT PRICE $795 Parallel $895 Serial (RS.232C) LOADED WITH INNOVATIONS • 40, 80 or 120 columns (software selectable) • Non-thermal paper, pin feed • 125 CPS, 70 lines per minute • 9 X 7 dot matrix • Vertical format unit • 96-character ASCII (upper and lower case) • Adjustable forms width to 9V2" • Parallel and serial (RS-232C) inter- faces available MICROTEKxa For more information contact: MICROTEK, Inc., 9514 Chesapeake Drive, San Diego, CA 92123 Tel.(7 14)278-0633 TWX 910-335-1269 Circle 9 5 for microTax CPA/Tax Professionals... Here's how you can solve your professional practice development problems Are you satisfied with the growth of your tax practice? Our field tested professional tax preparation software can help! One tax practitioner reported his tax season income jumped from $12,000to $30,000 using a micro computer |t can happen to you too!! Call or write for details. micreloK Complete System, including: •Federal Individual • State Individual • Corporate Income Tax Software Specialists CQCTIA/AQP dealer inquiries invited 3600 WILSHIRE BOULEVARD. #1510, LOS ANGELES, CALIFORNIA 90010 • (213) 738-9972 ) SOFTWARE Ad #5 RS— We want to i^e your software source. Give u sthe opportunity to beat any nationally advertised price! CP/M® DISK / Wi-#iti y^,^^ /MANUAL OSBORNE fl MANUAL/ ONLY ^General Ledger % 59/$20 #Acct Rec/Acct Pay. . $ 59/$20 #Payroll w/Cost $ 59/$20 Buy2 get 1 free $118/$57 A113andCBASIC2. . .$199/$71 DIGITAL RESEARCH CP/M' 2.2 Northstar. $149/$25 CP/M ^ 2.2 Cromemco . $ 1 89/$25 MICROSOFT Basic-80 $284/$25 Basic Compiler $324/$25 Fortran-80 $384/$25 MICROPRO Word-Star (Ver 2.0). . $349/$40 Word-Star /Mail-Merge $489/$65 DataStar $279/$35 Word-Master $1 19/$25 SuperSortI $199/$25 SuperSortll $169/$25 SuperSort Ml $119/$25 Tiny'C" % 69/$40 CBASIC (Ver 2.06)...$ 89/$15 Pascal/Z (Ver 3) $369/$35 Pascai/MT (Ver 3). . . $229/$30 Magic Wand $299/$45 CBS $279/$45 $11. M $369/$45 Electric Pencil II. . . . less 15% COMPUTER PATHWAYS #Pearl (level 1) $ 99/$25 ttPearl (level 2) $299/$25 #Pearl (level 3) $549/$25 PEACHTREE* ^ ^General Ledger $449/$35 tAccts Receivable $449/$35 tAccts Payable $449/$35 tPayroIl $449/$35 X Inventory $499/$35 tProperlyMgt $899/$35 tC.RA. Client Write-up. $899/$35 JMailing Address $399/$35 STRUCTURED SYSTEMS ^General Ledger $747/$25 #Accts Receivable. . .$747/$25 #Accts Payable $747/$25 # Payroll $747/$25 ttlnventor^ Control. . . . $447/$25 #Analyst $197/$15 #Letteright $167/$25 #NAD $ 87/$20 QSORT % 87/$20 GRAHAM-DORIANS ttGeneral Ledger $793/$35 #AcctsReceivable $793/$35 #Accts Payable $793/$35 ttPayroll $493/$35 # Inventory $493/$35 #Cash Register $493/$35 #Apartment Mgt $493/$35 #Job Costing . . $793/$35 MICRO-AP ttSelector III-C2 $269/$20 #SelectorlV $469/$35 ttGlector $299/$25 S-BasicCompiler $229/$25 WHITESMITHS *"C" Compiler $600/$30 *Pascal(incl"C") $750/$45 S.0.F.T.W.A.R.E.11 tMicrotax"^- Prof, tax preparation Federal individual, . . Federal corporate. . . State individual ^Business Plus* General Ledger AccountsReceivable. Accounts Payable. . . Payroll All 4 $749/$50 $249/$25 $249/$25 $ 79/$25 $ 79/$25 $ 79/$25 $ 79/$25 $269/$99 SUPERSOFT llForth $129/$25 Diagnostic I $ 49/$20 Other disk software . . less 10% APPLE II® MICROSOFT Softcard (CP/M) $292 PERSONAL SOFTWARE Visicalc^ $122 CCA Data Mgr $ 84 Desktop/Plan $ 84 MUSE Super-Text $ 84 Other disk software, less 10% TRS-80® MODEL II CP/M 2.2 $149 Electric Pencil II less 15% TRS-80® MODEL I CP/M 1,4 $129 CCA Data Mgr $ 68 Othersoftware requirements— Call CP/M users: specify disk systems and formats. Most formats available. -Requires microsoft BASIC Tl— Supplied in source code -Mfgs, Trademark * —Special Bonus with order tf -Requires CBASIC-2 VISA • MASTERCHARGE ORDERS ONLY-CALL TOLL FREE 1-800-854-2003 ext 823 Calif. 1-800-522-1500 ext. 823 Add$2. 50 postage and handling per each item. California residentsadd6% sales tax. Allow 2 weeks on checks. C.O.D. ok. Prices subject to change without notice. All items subject to availability For information write or call THE DISCOUNT SOFTWARE GROUP 1610 Argyle Ave.. BIdg. 102 • Los Angeles, CA 90028 • (213)665-8280 Z80 processor card and a Brand Z dynamic memory board. If they all work together it's a miracle! By more clearly defining things like DMA (direct-memory access) protocols and timing, as well as eliminating some of the archaic or abused S-100 signals, board compatibility can more likely be assured. Second, provisions have been made to ease the adaptation of new, higher-performance processors to the bus. This expandability has been achieved in three distinct ways: • 16-Bit Data Transfers — MITS chose to split the 8080's bidirec- tional 8-bit data bus into separate input and output data buses. While the wisdom of this was often questioned, it has proven to be a saving grace. The IEEE S-100 standard adds two signals (SXTRQ*, Sixteen Request, and SIXTN*, Sixteen Acknowledge) to allow 16-bit data transfers by ganging the input and output data bus. (Note that throughout this article I will use the "*" notation to designate active low signals; this is the accepted usage in the IEEE standard.) • Extended Memory Addressing — Eight of the unused S-100 bus lines have been designated as address lines A16 thru A23. With 24 address bits (AO thru A23), 16 megabytes of memory can be addressed directly. • Extended I/O (input/output) Addressing — The 8080 was capable of addressing 256 I/O ports. The 8-bit I/O port ad- dress was placed on both the low byte (AO thru A7) and high byte (A8 thru A15) of the 16-bit address bus. The IEEE standard allows this echoing of the port address on both halves of the address bus, but recommends that AO thru A15 be used for I/O addressing. The 16-bit I/O address gives S-100 systems the ability to directly utilize up to 64 K I/O ports. These standardization efforts will allow a controlled evolution of the S-100 bus. However, I realize that of the dozens of S-100 boards I have (in- cluding some of very recent vintage), probably none meets the IEEE stan- dard. I cannot afford to replace them 48 September 1980 © BYTE Publications Inc Circle 30 for THE DISCOUNT SOFTWARE GROUP Buy now and get FREE Solid State Software Libraries. TI Programmable 59 — $300* TI Programmable 58C — $130* Choose from these. TI Programmables lead the field in performance, quality and value. When you're choosing a program- mable calculator consider: Power. Ibtal software support. Flexibility. And price/performance. You'll dis- cover a clear-cut answer. A TI Pro- grammable 58C or 59. The TI-59 has up to 960 program steps or up to 100 memories. Mag- netic card read/write capability lets you record your own custom pro- grams or those received from PPX (Professional Program Exchange). The TI-58C features up to 480 program steps or 60 memories. And it has TFs Constant Memory'" fea- ture that retains data and program information even when the calcula- tor is turned off. And now free modules give you that added productivity you need. From August 15 to October 31, 1980 is your special opportunity to pur- chase one of the world's most ad- vanced programmable calculators. And get a minimum of $40 worth of free software modules with a TI- 58C. Or, when you buy a TI-59, get a minimum of $80 worth of software modules and an $18 one-year mem- bership in PPX. This will allow you to select up to 3 programs (from over 2,500) written by professionals in your field. Visit your TI retailer for more in- formation, and let him help you se- lect the TI Programmable and free software that's right for you. I D I've bought a TI-58C, send me my free module. Here is I my first choice and an alternate, n I've bought a TI-59, send me my two free modules and my membership (which entitles me to select three pro- grams from the source catalog at no charge). Here are my module choices and an alternate. 1 2 3 Send to: TI Library Offer, P.O. Box 1384. Lubbock, TX 79408. Return this coupon: (1) with customer information card (packed in box), (2) a dated copy of proof of purchase , between Aug 15 and Oct 31. 1980— items must be post- markedbyNovZ, 1980. Name Address City State Zip Calculator Serial Number (from back of unit) Please allow 30 days for delivery. Offer void L where prohibited. Offer good in U.S. only. TI resefves the right to subslriute modules. ^_ ^_ 4:U.S. suggested retail for all Li- braries is $40, except Farming, $55, and Pool Water Analysis, $45. **For use with TI-59 only BY Fifty Years . of Innovation Texas Instruments technology — bringing affordable electronics to your fingertips. *US suggested retail price. © 1980 Texas Instruments Incorporated Texas Instruments INCORPORATED Circle 31 on inquiry card. BYTE Seplember 1980 49 C-BUS 11 EXECUTION r UNIT ^ INSTRUCTION STREAM BYTE QUEUE CONTROL SYSTEM A-BUS n AH AL BH BL CH CL DH DL SP BP SI Dl ^^ ARITHMETIC/ LOGIC UNIT OPERANDS FLAGS Figure 1: The internal architecture of the 8088. By combining a 16-bit execution unit with an 8-bit bus-interface unit, the 8088 can use a powerful instruction set and still re- main compatible with most existing hardware. The functional division of processing allows the 8088 a speed advantage by periorming fetch and execute concurrently. all. In fact, my IMSAI computer's front panel does not meet the stan- dard either. A Solution Intel's 8088 microprocessor is a remarkable machine. By combining a 16-bit execution unit with an 8-bit bus interface, the 8088 can represent the best of both worlds for many users. (See figure 1.) In particular, the 8088 allows you to reap the benefits of a powerful new architecture while preserving your investment in 8-bit hardware. In addition, many data- handling-oriented applications (such as intelligent terminals, data concen- trators, and small business com- puters) are more naturally im- plemented with a machine that com- municates using 8-bit characters. New Architectures The microprocessor revolution is fascinating because it represents a microcosm of the computer revolu- tion. In the last 5 years we have seen computers on silicon follow the footsteps of 30 years of computing history. The effort of the computing pioneers has not been in vain, for it has served to chart our course. Consider current VLSI (very large scale integration) processing tech- nologies. Semiconductor manu- facturers have the capability of plac- ing 30,000 transistors on a chip of silicon today, with as many as 100,000 in the near future. Now ima- gine a second-generation mainframe computer of the 1960s. It fills an air- conditioned room and consists of large metal boxes and massive power supplies. Inside some of the metal boxes are large racks filled with cir- cuit cards. These circuit cards are covered with transistors, resistors, and capacitors. Today, the com- puting equivalent of these metal boxes is a small group of integrated circuits. The user may be initially impressed by the complexity of the computer being used, but he will ultimately judge the machine on the basis of its power and ease of use; therefore, the challenge for the manufacturers is not as simple as maximizing the number of devices. The problem is designing microprocessors that respond to the needs of the user. The high-performance solution is to implement mainframe architec- tures that contain tried and proven virtues. Concepts like attached co- processors, concurrent I/O process- ing, pipelining, memory segmenta- tion and hardware mathematical operations are being adopted and put on silicon. When I say the architec- ture of the 8088 is "new and revolu- tionary," I am really saying that the day of the "mainf rame-on-a-chip" has arrived. The Best of Both Worlds The 8088 contains two processors in its 40-pin package. One is called the EU (execution unit) and the other is the BIU (bus-interface unit). The BIU is optimized for communicating with the rest of the computer system, while the EU is optimized for exe- cuting programs. The EU most closely resembles what is conventionally considered the processor; it contains the working registers, the status flags, and the ALU (arithmetic/logic unit). As its name implies, this is where programs are executed. The EU of the 8088 is the same as the one in the 16-bit 8086 processor. All the registers (twelve of them) are 16 bits wide, though some of them can be treated as two separate 8-bit registers by the programmer. In addi- tion, all math operations (addition, subtraction, multiplication and divi- sion) can utilize 16-bit operands. The 8-bit BIU manages much of the work associated with the address, data, status, and control bus inter- faces. The BIU of the 8088 uses an 8-bit data bus for receiving and transmitting data, as opposed to the BIU of the 8086, which uses a 16-bit data bus. An example of the bus- handling optimization of the BIU is that the speed requirements placed on the rest of the system (ie: memory and I/O devices) are very easy to deal with. An 8088 running at 5 MHz can use relatively slow memories (ie: 450 ns access time) with no wait states. Save those old, slow memory boards. The connection between the BIU (which fetches and stores data) and the EU (which processes the data) is the queue or pipeline. The BIU keeps the pipeline filled with instructions fetched from memory, while the EU draws instructions from the queue as it needs them. In less sophisticated computers, the rest of the system (especially memory) might sit idle, waiting for the processor to finish a long instruc- tion. To eliminate this waste of 50 September 1980 © BYTE Publications Inc Circle 32 on Inquiry card. .U I O Lh SCHOLL HUWtH 7^^^5^S=S5?^3^ 4i^:f if Diablo printers spend more time in this position. A printer isn't much good if it can't do the ^ job when it's needed. That's why, at Diablo, we don't just design ■^ printers that work. We design printers that keep ^-^ on working. In fact, we mate them so reliable, you can just open the carton, plug in and play. Diablo offers the widest range of reliable printers and options to give the flexibility you need. Which stands to reason. After all, we pioneered the daisy wheel technology and we're still the leader in it. So if your printers spend too much time in the "off' position, you know what to do. ., Switch. U.;-|^^P Diablo Systems •'i'i XEROX Diablo® and XEROX® arc trademarks of XEKOX COKPOKATION. ■'^i' :-A-^ system resources, the BIU of the 8088 will fetch more information and put it in the queue for later use by the EU. Similarly, when the BIU tries to read some extra-slow memory and en- counters a wait state, the EU can con- tinue reading instructions from the queue and executing them. All the EU ever "sees" is the queue, regardless of differences in the BIU that feeds it. This powerful internal architec- ture, combined with the simple 8-bit I/O, makes the 8088 a natural for the S-100 and other 8-bit buses. Design and Interfacing My S-100/8088 board is designed as a simple, yet powerful, base com- puter with the support logic necessary to interface to the S-100 bus. I will ex- plain the design accordingly by first discussing the design of the minimal system, and then the techniques for interfacing to the S-100 bus. Several years ago it would not have been uncommon to overhear: "My computer's got a microprocessor, 2 K bytes of EPROM, 1 K bytes of pro- grammable memory, and a couple of I/O ports." Today, the same machine can be created using four integrated circuits. In fact, such a system is shown in figure 2. This system uses a 5 MHz 8088 pro- cessor, driven by an 8284 clock generator, with an 8185-2 l-K-by-8- bit static memory circuit and an 8755A-2 2-K-by-8-bit EPROM (erasable programmable read-only memory). The 8755A-2 also includes two 8-bit parallel ports. Notice how simple the basic system is. Each part was designed with com- patibility in mind, so the interfacing task is essentially "connect the dots." The 8088 Microprocessor In the following section, detailed hardware aspects of these key com- ponents will be discussed. My reference is Intel's 8086 Family User's Manual, which contains a wealth of information on the 8088, 8086, and other high-performance members of o a- U- ' \^ ^^■ r>- -3 SYNC r/c 1 p>o L 1 H-2 SYNC . ^ 3 r^ CK RDY 1 ^ 1 .^ l- AENl ^^^ — ' "N^ AEN2 ' ^ H ^ J y V -RESET OSC READY RDY2 Figure 6: The 8284 clock generator. This device provides an optimum clock signal and serves to buffer and condition some of the basic processor signals. Figure 6a shows the pin labeling for the device, while figure 6b shows a block diagram of its internal struc- ture. 62 Seplember 1980 © BYTE Publications Inc Digital IC Probe 6* Logic Pulser PRB-1 DIGITAL LOGIC PROBE Compatible with DTL, TTL CMOS, MOS and Microprocessors using a 4 to 15V power supply. Thresholds automatically programmed. Automatic resetting memory. No adjustment required. Visual indication of logic levels, using LED's to show high, low, bad level or open circuit logic and pulses. Higbly sophisticated, shirt pocket portable (protective tip cap and removable coil cord). Automatic threshold resetting • DE to > BO MHZ Compatible with all logic families 4-lB VDC • lONsec. pulse re^onse Supply O.V.P. to ± 70 VDC • 120 K H impedance No switches/no calibration • Automatic pulse stretching to 50 Msec. Open circmt detection • Automatic resetting memory Range extended to 15-25 VDC with optional PA-1 adapter PLS-1 LOGIC PULSER The PLS-1 logic pulser will superimpose a dynamic pulse train ( 20 pps) or a single pulse onto the circuit node -under test. There is no need to unsolderplnsprcutprmted-cipcult traces evenwben these nodes are bemg clamped by digital outputs. PLS-1 is a multi-mode, high current pulse generator packaged inahand-held shirt pocket portable instrument. It can source or sink sufficient current to force saturated output transistors in digital circuits into the opposite logic state. Signal Injection is by means of a pushbutton switch near the probe tip. When the button is depressed, a single high-going or low-going pulse of 2fi sec wide is delivered to the circuit node under test. Pulse polarity is automatic: high nodes are pulsed low and low nodes are pulsedhlgh. Holding the button down delivers a series of pulses of 20 pps to the circuit under test. High input impedance (off state) 1 meg ohm • Multi mode-single pulses or pulse trains Low output impedance (active state) 2 ohms • Automatic polarity sensing Output pulse width 2 fxsec nominal • Automatic current limiting; 7 amps nominal Input over voltage protection + 50 volts • Automatically programmed output level Finger tip push button act\iated • Circuit powered Power lead reversal protection • No acy ustments required Multi-femily RTL, DTL, TTL. CMOS, MOS and Microprocessors. PRBl DIGITAL LOGIC PROBE $36.98 PA 1 HIGH VOLTAGE ADAPTER $8.80 PCI POWER CORD. Alligator Clips $4.98 PT2 REPLACEMENT PROBE TIP(2) $1.80 PC 2 POWER CORD, Micro Hooks $9.98 PLS 1 LOGIC PULSER $48.98 OK Macliine & Tool Corporation 3455 Conner St., Bronx,N.Y. 10475 U.S.A. Tel. (212) 994-6600 Telex 125091 ^ *Minlmum billings $26.00, add shipping charge $2.00 New York State residents add applicable tax Circle 41 on inquiry card. BYTE September 1980 63 PIN CONFIGURATION 8755 A BLOCK DIAGRAM PROG AND CEi [ 8755A/ CLK [ 3 8755A-2 38 7a RESET [ 4 Vdd [ 5 READY [ 6 lO/M [ 7 Tor [ 8 RO [ 9 low [ 10 ALE [ 11 ADo [ 12 ADi [ 13 AD2 [ U AD3 [ 15 AD4 [ 16 AD5 [ 17 ADg C 18 AD7 [ 19 \J^ 40 ] Vcc ]PB7 ^SS 20 ADf ADiL^ AD2|~3 AD3[T AD4Q; AD5[T ADeCT AD7|~8" vssEE 8185 ADq- AD7 C 7d 37 36 35 34 33 3 2 31 30 29 28 27 26 25 24 23 22 21 ]PB6 ]PB5 ]PB4 ]PB3 ]PB2 ]PBi ]PBo ]PA7 ]PA6 ]PA5 ]PA4 ]PA3 ]PA2 ]PAi ]PAo ]aio ] Ag ]A8 lejvcc T7]rd 16~|WR Tr]ALE TTlcs TTJAg To~|a8 AD0.7O '^s-io CE2 - lO/M - ALE - RD ■ low ■ RESET • iOR ■ PROG/CE~i • 2KX8 EPROM PORT A ^DD PAo-7 PORT B :}pBo-7 -Vss(OV) 7h 7c cs- CEi- CE2- RD - WR - ALE - R/W LOGIC ^ DATA BUS BUFFER IK X 8 MEMORY ARRAY X-Y DECODE :> As • Ag - ALE - ADDRESS LATCH Figure 7: Pinouts and block diagrams of the 8755A-2 EPROM (figures 7a and 7b) and the 8185-2 user programmable memory (figures 7c and 7d). These circuits were designed specifically to work with the 8088 multiplexed bus lines; they provide two 8-bit parallel I/O ports without any additional hardware. bus; and finally stops the processor once the jump is completed. Similarly, for Examine-Next and Deposit-Next functions, the front panel jams and executes a NOP (no- operation, hexadecimal 00) instruc- tion to move on to the next location. The JMP and NOP instructions for these switch functions are hard- wired into the front-panel circuitry; circuit traces must be cut to change them. Since the operation codes for the 8088 are completely different, every attempt at front-panel opera- tion would produce bizarre results. Other difficulties include the two's-complement representation of 8088 JMP addresses and the IMSAI's use of S-100 control signals that have been outlawed by the IEEE standard. Because of these difficulties, I decided to base my 8088 project on a different S-100 system. Fortunately, I was able to scrounge a vintage BYT-8 S-100 box at the local electronic flea market for a good price. The box did not contain any circuit boards, but the metal panel on the front did have cutouts for various LEDs (light- emitting diodes) and switches, which I used to implement a minimal front panel (see photo 1). While I agree with the principle of turnkey systems, which have only power and reset switches, a front panel is a useful tool for debugging any new hardware design. The front panel is a "window" into the machine, one that is needed in case the system does not work perfectly the first time. Next Month Next month's installment will cover some of the more interesting aspects of interfacing to the S-100 bus, in- cluding the amount of TTL "glue" necessary to emulate the control and status signals of the S-100 standard and the construction of the actual processor board. ■ References Both the 8086 and 8088 microprocessors have been discussed by Steve Ciarcia in "Ciarcia's Circuit Cellar" articles in BYTE, as follows: 1. "The Intel 8086". November 1979 BYTE, page 14. 2. "Ease Into 16-Bit Computing: Get 16-Bit Performance from an 8-Bit Computer", March 1980 BYTE, page 17. 3. "Ease Into 16-Bit Computing, Part 2: Examining a Small Multi-User System", April 1980 BYTE, page 40. 64 September 1980 © BYTE Publications Inc ook what's happened to HIPL0T TM DMP-4 $1,385- DMP-3 $1,250' DMP-6 $1,850* DMP-7 1,985' It's grown into a complete family of quality low cost digital plotters Circle 42 for literature In just two short years, The HIPL0T has become the most popular digital plotter among small systems users. With a record like that, what can we do for an encore? WE'VE IN- TRODUCED A COMPLETE LINE OF HIPL0TS...with a model suited for just about every plot- ting application. The HIPL0T DMP Series is a new family of digital plotters with both "standard" and "in- telligent" models available with surface areas of 8y2" x 11" (DIN A4) and 11" x 17" (DIN A3). For the user needing a basic reliable plotter, we have the "old stan- dard" DM P-2 (8y2 " X 1 1 ") and the "new standard" DMP-5 (11" x 17''). For those needing a lit- tle more capability, there are the DMP-3 (8y2" x 11") and the DMP-6 (11" X 17")-both TM HIPLOT and DM/PL are Trademarks of Houston Instrument Yes, they are UL listed! * * microprocessor controlled and providing easy remote position- ing of the X and Y axes (perfect for the OEM). For those who want this intelligence plus the convenience of front panel elec- tronic controls, we've provided the DMP-4 (8y2'' x 11") and the DMP-7 (11" X 17"). The "standard" plotters come complete with an RS-232-C and a parallel interface. The "intel- ligent" DMP plotters accept data from either an RS-232-C or Centronics data source. For the "standard" plot- ters, software is available from our ever expanding ''Micrographic Users Group." The "intelligent" HIPL0TS use our exclusive DM/PLtm language which min- inimizes plot software to a fraction of that normally as- houston instrument GRAPHICS DIVISION OF BAUSCH&LOMB Circle 375 to have representative call sociated wth digital plotting. With the new DMP Series, high quality digital plotting can now be a part of your system. It just doesn't make sense to be without this valuable tool when there is a DMP plotter with the plot size, speed and capabilities that are exactly tailored to your specific needs. ..and your budget. Prices for the DMP series range from $1,085* to $1,985*. For complete information and descriptive literature, contact Houston Instrument, One Houston Square, Austin, Texas 78753. (512) 837-2820. In Europe contact Houston Instrument, Rochesterlaan 6 8240 Gistel, Belgium 059/277445. For rush literature requests and sales of- fice information, persons outside Texas call toll free 1-800-531-5205. 'U.S. suggested retail prices only. "DMP 2, 3 and 4 UL listed DMP 5, 6 and 7 UL listing pending M7 Communicator A complete A/D and D/A Control System - Interface your computer to the analog world of process monitoring trans- ducers and controlling actuators. «S The M7 multiplexes analog and digital signals from your process sensors-temperature, pressure, level, flow, mass, strain, etc. -and continuously down-loads this data in digital form to your computer for display and processing. Simulta- neously, command signals are transmitted to the control devices in your process. Order a complete basic M7 System ready for round-the- clock process control- including a 16/32-Channel A/D Input Module (expandable to 256 channels), a Computer Interface Module, and a 4-Channel (expandable) D/A Output Module. Supplied com- plete with cabinet, power supply, and all necessary hardware and software for basic control. Bus accommodates eight additional modules. Specify computer make and model when >^, ordering . . . each $2,990 Or, order individual .__^ IEEES-100 '"'*"^^^1 building block modulesi Supplied complete with fundamental control software: A/D Module, AIM<12 • 1 6/32 channel • 1 2-bit precision/accuracy • 30 kHz data rates • 1 - 1 000 gain amplifier optional from $575 Thermocouple Compensation Module, THM-8 • 16 Inputs $350 Signal Conditioners, SIG-1 • Long-line drive $325 Additional Support Programs, PROG A,B,C... • Signal averaging • control functions • special display • etc from $1 00 D/A Module, AOM-12 • 4-channel (expandable) • 1 2-bit precision/ accuracy • Output: selectable voltage ranges and oscilloscope from $495 Control Output-Current Module, VIC 4-20 • 4-20 mA standard industrial control output • 12-bit pre- cision/accuracy • 4-channel • Use with AOM-12 $395 Programmable Clock/Calendar Module, CLK-24 • Minimum 1 year back-up $250 Parallel Output Module, REL-8 • 8-channel on-off (bang-bang) control $325 Add-On Nonvolatile Memory Modules • 4K and 8K bytes from $320 DUAL SYSTEMS CONTROL CORP. 1 825 Eastshore Hwy. Berkeley, CA 94710 (415)549-3854 system reliability/system integrity ^WBPammi OoicMes Time Your Tape John OTIaherty, St Louis Veterans Administration Medical Center, St Louis MO 63125 Recently I was involved in a research program that required long-term recording (eight hours) of physio- logical data on an analog instrumentation recorder. We needed a quick method of searching the tape for informa- tion occurring at certain times. Although a time marker was recorded on one channel, it could not be played back during fast-forward operation. Unfortunately, although the take-up-reel turns counter indexed unique locations on the tape, the readings obtained did not correlate sim- ply with time. Obviously, one turn on a fully wound reel contains at least twice as much tape as one turn on a bare hub. I developed a computer solution to the problem. Given the diameter of the take-up-reel hub, the length of the tape, and the turns-counter reading at the end of the tape, the program of listing 1 prints a table relating turns- counter reading, elapsed time, remaining time, footage used, and footage remaining. The method used is simple (now I): the single datum needed is an accurate value for tape thickness as wound, and it is found by considering the side of the tape first as a very long, very thin rectangle, and then as a circle. The area of the side of the tape (ie: what is seen as you face the reel on its axis) can be approximated by a linear function of tape thickness: Area = Tape Thickness X Tape Length or by a nonlinear function of tape thickness: Radius = Tape Thickness X Turns Count + Hub Radius Area = tt X (Radius)^ — Hub Area TAPE THICKNESS - Figure 1: Area occupied by the side of a given length of tape as tape thickness is changed. The X-axis value at the nonzero in- tersection of area calculated by two different methods must be the actual tape thickness. 66 September 1980 © BYTE Publications Inc Circle 43 on Inquiry card. Please send your free software catalog. (Check which software is of particular interest) D C COMPILER. Optimized native code for VAX 11/780, PDP-11, LSM1, Z80, 8085, 8080. Full C language as defined in Kernighan and Ritchie, with conn- prehensive portable library. Cross compilers available. Runs under VMS, IAS, RSX-11D, RSX-11M, RSTS/E, RT-11, UNIX, Idris, CDOS, CP/M. From $600 D IDRIS OPERATING SYSTEM. System calls and file system identical to UNIX V6, including pipelines. Utilities include shell, editor, assembler, loader, archiver, compare, copy, grep, etc., plus system utilities for file system maintenance. Runs on LSI-11, PDP-11. From $1000. D PASCAL COMPILER. Optimized native code for VAX 11/780, PDP-11, LSM1, Z80, 8085, 8080. Full Pascal language as defined in Jensen and Wirth, with standard library. Includes C compiler and portable library, permitting intermixed C and Pascal. Cross compilers available. Runs under VMS, IAS, RSX-11D, RSX-11M, RSTS/E, RT-11, UNIX, Idris, CDOS, CP/M. From $750. Name. Connpany_ Street City _State_ .Ztp_ Idfis is a trademark of Whitesmiths Ltd. UNIX is a trademark o1 Bell Laboratories. CP/M is a trademark ot Digital Research Co. VMS. RSX-11. RT-11. RSTS/E. VAX, PDP-11. LSI-11 are trademarks of Digital Equipment Corporation. Whitesmiths, Ltd Software for Ptownups. (212)799-1200 ^ RO.B. 1132 Ansonia Station. New York, N.Y. 10023 NOW youKE TALKING! THE SOURCE MICRONET CBBS: COMPUTER BULLETIN BOARD SYSTEM YOUR COMPUTER WITH BSTMS THE ASYNCHRONOUS DIAL-UP ABBS: APPLE BULLETIN BOARD SYSTEM YOUR CHOICE l< BSTAAS n Byrom Software Terminal Monitor System The missing link between your CP/M system and remote computers everywhere! ■ talks to most dial-up remote computers. ■ stores data from remote computers in CP/M files. ■ copies data to CP/M list device if desired. ■ transmits files to the remote computer. ■ it will even "talk" to another CP/M console. ■ features EXPAND and COMPRESS programs to translate binary files into character files and vice versa. ■ uses the same simple Installation procedure as BSTAM. This system is great for recording data from remote time-sharing systems! It makes it possible to do local processing of data on a micro and then transmit it to the mainframe. $200 per computer. $15 for manual alone. Prices reflect distribution on 8" single density dIaVettea. II a format is requested which requires additional diskettes, a surcharge of $8. per additional diskette will be added. Apple is a trademark of Apple Computer. MicroNET is a trademark of CompuServ. CP/M is a trademark of Digital Research. Lifeboat Associates 1651 Third Avenue, New York, N.Y. 10028 (212)860-0300 Telex: 220501 which actually runs 32 the tape length was pre- Lines 30 thru 80 of listing 1 find the intersection of these two functions by iteration for a fully wound reel of tape. (See figure 1.) Then lines 95 thru 230 generate a table by finding area through radius, and length and time from area for turns-counter increments of ten. It has not been possible to test the routine on the in- strumentation recorder yet, but I have applied the method to my own cassette recorder with very good results. For a C-60 cassette, minutes, 23 seconds per side, calculated to be (1943 s X 1% ips/12) = 303.6 feet.' By carefully disassembling the cassette, the hub diameter was found to be 0.8525 inches (five cassettes from dif- ferent manufacturers were found to be identical in this respect). The ratio of indicated to actual turns of the take- up reel was found by turning the reel one hundred turns by hand (an index mark helps), and noting the turns- counter reading. Then the program was run and table 1 (see page 74) was printed, and its accuracy was tested by actually running the tape and noting the times for turns-counter increments of ten. The test results are printed as the last two columns in the table. As can be seen, the worst case error is 5 seconds, or 0.3% of the total time, which is surprisingly good, in view of tape counters' reputed inaccuracy, and the fact that no empirical trimming was done — the algorithms simply try to represent the physical realities of the situation. One might also use the formulas above to program a portable calculator to find time for turns count or vice versa, without consulting a table. Listing 1: An Applesoft BASIC program for correlating turns- counter readings with time. All documentation statement line numbers end in 5, and they may be ignored when keying in the program. 5 REM SET CDNSTRNTS t MENTIDN VR RIRELES FDR EFFICIENCY in PI = 3. 14159c:654:Tl..l = £ : M = 1: T 'v' = 1 £: : D ij = . ij ij ij ij ij 1 : H S = iJ : TT = nrlTC = i:i:HH = SbCiUiMM = t firHF = U.5:TC = U £U HOME : GDTD iLMJU £.'5 REM FIND RCTURL TRPE THICKNE 3i:i PRINT "CRLCULRTING TRPE THICK MESS RS WDUHD- . - " 35 REM RRER BY P I '::R-^-c:> MUST EQUR L 411 Rl = PI ♦ oiMTC ♦ TT + HS::- •-• T I..J - HS •"•• TW;' 45 REM RRER BY L^M 511 R£ = ML ♦ TT ♦ TV bU CR = Rl .-■• R£':TT = TT .•■" CR 65 REM SD TRY NEW TT TILL IT DD 7 III IF RBs ■::i..i - cr: nn THEN 4 811 PRINT : RETURN 95 REM GENERRTE TRBLE liJU FDR ITC = n TD MIT STEP 1 U Listing 1 continued on page 70 68 September 1980 © BYTE Publications Inc Circle 44 on inquiry card. A Few Extraordinary Products for Your 6800/6809 Computer From Percom . . . Low Cost Mini-Disk Storage in the Size You Want Percom mini-disk systems start as low as $599.95, ready to plug in and run. You can't get better quality or a broader selection of disk software from any other microcomputer disk system manufacturer — at any price I Features: 1 -, 2- and 3-drive systems in 40- and 77-track versions store 1 02K- to 591 K-bytes of random ac- cess data on-line • controllers in- clude explicit clock/data separation circuit, motor inactivity time-out cir- cuit, buffered control lines and other mature design concepts • ROM DOS included with SS-50 bus ver- sion — optional DOSs for EXOR- ciser* bus • extra PROM sockets on-board • EXORciser* bus version has 1 K-byte RAM • supported by ex- tended disk operating systems; as- semblers and other program de- velopment/debugging aids; BASIC, FORTRAN, Pascal and SPL/M lan- guages; and, business application programs. EXORciser* Bus LFD-AOOEX'^'^ -SOOEX^"^ Systems Versatile Mother Board, Full-Feature Prototyping Boards Printed wiring is easily soldered tin-lead plating. Substrates are glass-epoxy. Pro- totyping cards provide for power regula- tors and distributed capacitor bypassing, accommodate 14-, 16-, 24- and 40-pin DIP sockets. Prototyping boards include bus connectors, other connectors and sockets are optional. MOTHERBOARD — accommodates five SS-50 bus cards, and may itself be The SBC/9^, A "10" By Any Measure. The Percom SBC/9^ is an SS-50 bus compatible, stand- alone Single-Board Computer. Configured for the 6809 microprocessor, the SBC/9^ also accommodates a 6802 without any modification. You can have state-of-the-art capability of the '09. Or put to work the enormous selection of 6800-coded programs that run on the '02. The SBC/9™ includes PSYMON™, an easily extended 1- Kbyte ROM OS. Other features include; • Total compatibility with the SS-50 bus. Requires no changes to the motherboard, memory or I/O. • Serial port Includes bit-rate generator. RS-232-C compatible with optional subminiature 'D' connector installed. 10-pin Molex connec- tor provided. • Eight-bit, non-latched, bidirectional parallel port is multi-address extension of system bus. Spans a 30-address field; accommodates an exceptional variety of peripheral devices. Connector is optional. • Includes 1-Kbyte of static RAM. • Costs only $199,95 with PSYMON™ and comprehensive users manual that includes source listing of PSYMON^'^. ''" trademark of Percom Data Company, Inc. • trademark of the Motorola Corporation. Prices and specifications subject to change without notice. plugged Into an SS-50 bus. Features wide-trace conductors. Price; $21.95 SS-50 BUS CARD — accommodates 34- and 50-pln ribbon connectors on top edge, 10-pin Molex connector on side edge. Price; $24.95. 88-30 BUS CARD — 1 y4-inch higher than SWTP I/O card, accommodates 34- pin ribbon connector and 12-pin Molex connector on top edge. Price; $14.95. The Electric Window'^'^: Instant, Real-Time Video Display Control Memory residency and outstanding software control of display format and characters make this SS-50 bus VDC card an exceptional value at only $249.95. Other features; • Generates 128 charac- ters including all ASCII dis- playable characters plus selected Greek letters and other special symbols. • Well-formed, easy-to- read 7x12-dot characters. True baseline descenders. • Character-store (display) memory Included on card. • Provision for optional character generator EPROM for user defined symbols. • Comprehensive users manual Includes source listing of Driver software. Driver — called WINDEX^ — is also available on mini- diskette through the Per- com Users Group. PEFQOM PERCOM DATA COMPANY. INC. 211 N. KrRBY GARLAND. TEXAS 75042 (214] 272-3421 Products are available at Percom dealers nationwide. Call toll-free. 1-800-527-1592, for the address of your nearest dealer, or to order direct. Listing 1 continued: llfi TC = ITC ♦ IF: l£i:i R = TC ♦ TT + HS 13111 R = PI ♦ (R ••■• TI...I - HS ••■• TI...1::' 1411 L = R .••• TT 15 III Tl = L .-■ SPIi 1611 12 = m;kt - Tl 170 Fl = INT '::L .-- TV + HF!:' ISO F£ = INT a-1L - Fl + HF!:' 190 PRINT ITC; TRE':: S!:' J : TM = Tl: bDSUB 300 £00 PRINT TREC 18>;:TM = T2: GDSUE '3 £10 print trec £:9::'f1 tre':! 35::' fe 220 if cl = i...i then £6 £3 ne:kt £35 REN ££0r.£40r.£50 TD i::LD:i:E Tfl ELE NERTLY IF INT ailT .•■■• 10:5 = MIT .•■• 1 THEN £6 i::LD:i:E = irlTC = MIT: GDTD 110 END REM CONVERT :i:EC TD HR!.NIN!.:S EC RND PRINT TM = INT (TN + HF::' H = INT CTM .■••• HH::':TM = TM - '::H ♦ HH::' M = irHT an .'- mm::- ^s = tn - •:: N ♦ Mr-i> MO ib £95 3 310 3£ the electric pencil II for the TRS-80 Model IV Computer The Electric Pencil is a Chorocter Oriented Word Processing System. This means that text is entered as o continuous string of dxrocters end is monipuloted as such. This allows the user enormous freedom 3id eose in the movement and hondling of text. Since lines are not delineated, any number of char- octers, words, lines of paragraphs moy be inserted or deleted onywhere in the text. The entirety of the text sh'ifts end opens up oi- closes as needed in full view of the user. Cor- rioge returns as well as word hyphenation ore not required since eoch line of text is forrnotted automaticotly. As text is typed and the end of o screen line is reached, o partially completed word is shifted to the beginning of the following line. Whenever text is inserted or deleted, existing text is pushed 6own or ptjlled up in a wrap around foshion. Everything appears 00 the video display screen os rt occurs thereby eliminating cny guesswork. Text may be reviewed at wil I by vorioble speed or poge-ot-a-fime scrolling both in the forward end reverse directions. By using the seorch or the seorch and replace function, any string of characters moy be locoted end/or reploced with cny other string of chorocters os desired. Specific sets of characters within encoded strings moy also be located. When text is printed, The Electric Pencil outomaticolly inserts corriage returns where they are needed. Numerous ccmbinotioos of Line Length, Page Length, Chorocter Spacing, Line Spacing end Poqe Spacing allow for any form to be handled. Right juslification gives right-hand margins that are even. Pages may be numbered os well os titled. the electric pencil d Proven Word Processing Svsteii The TRSDOS versions of The Electric Pencil II ore our best evw! Yoo con now type as fast os you like without losing ony chorocters. New TRSDOS features include word left, ward right, word delete, bottom of poge numbering as well as extended cursor controls for greater tiser flexibility. BASIC files may olso be written end simply edited without additional softwore. Our CP/M versions ore the saive os we hove been distributing for several years end oUow the CP/M user to edit CP/M files \vith the oddition of cor CONVERT utility for on odditionol $35.00. CONVERT is not required if only quick end eosy word processing is re(;uired. A keyboard buffer permits fast typing without chorocter loss. CP/M TRSDOS Seriol Diablo, NEC, Oume $ 300.00 $ 350.00 All other printers $ 275.00 $ 325.00 The Electric Pencil I is still ovoiloble for TRS-80 Model I users. Although riot as sophisticated os Electric Pencil II, it is still on extremely eosy to use end powerful word processirig system. The software hos been designed to Ix: used with both Level I (I6K system) ond Level II models of the TRS-80. Two vcrsiens, one for use with cossette, and exie for use with disk, ore ovoiloble on cassette. The TRS-80 disk versio is easily tronsferred to disk end is fully interactive with tlie READ, WRITE, DIR, and KILL routines of TRSDOS. TRC Cassette $ 100.00 TRD Disk $ 150.00 70 September 1980 © BYTE Publications Inc Features TRSDOS or CP/M Compotible • Supports Four Disk Drives • Dynamic Print Formotting • Diablo, NEC & Oume Print Pockages » Multi-Column Printing • Print Value Choining • Pagf-Qt-o-t ime Scrolling • Bidirectionol Multispccd Scrolling * Subsystutn with Print Vahje Scoreboard • Automatic Word & Record Ni/nber Tolly • Clobol Search & Replace • Full Morgin Control • End of Poge Control • Non Printing Text Commenting • Line & PorOgrcph Indenfofion ♦ Centering • Underlining » Boldface ss MICHAEL SHRAYERSOFTWARE. INC. l198LosRoblesDr. Palm Springs, CA. 92262 (714)323 1400 so: PRINT SO: PRINT S 3£5 REM PRETTVPRINTING 33 Q = H: Gn:i:UE 341:1 Q = r-l: Gn:i:UE 35 U Q = Si Gn:SUE 36 RETURN :380 IF Q < 10 THEN PRINT " " ; 390 PRINT Q; : RETURN 995 REM INPUT NECE:i::i:RRY INFDRMR T I Dh 100 INPUT "HUE IHRMETEPaNCH::'? '•;H:i::H:i: = H:i: .••- £ 1010 INPUT "TRPE LENGTH LE:i:S LER HER CFEET:- ? " ; ML 10£0 INPUT "TURN::: CDUMT RT END F TRPE? "JMIT 10 30 PRINT "TURN:i: CDUNT RERIUNG FDR" 1035 REM MTC WILL EE RCTURL TURN:i: COUNT 1 04 1 05 1 06 107 1 USO I 09 I I 1110 1115 1 1 £ 11£5 1 1 3 1135 114 1145 115 1 1 6 117 1175 1 1 S £0 05 £015 £0£5 £035 £045 £055 £065 £075 £0:E:5 £095 :3 05 3 015 3 £5 INPUT URN:£? = MIT PR I NT PRINT PRINT PRINT PR I NT PRINT INPUT :i:PIi REM FROM :i:PIi = REM MXT = REM RND IR: ♦ IR 1. . 100 RCTURL TRKE-UP T IR = 100 . 15.-16 . I-7.-S . 3 -3. •■••4 .7-l.--£ ■5. . . 15 ■ 6 . . .3 •MHICH TRPE :: IR:MTC •4, IP:i: I PS IP:i: IP:i: I PS I PS ;:PEEIi SPEED KLUGE TD FIND TRELE ENTRY .9375 ♦ £ ••■• CSPIi - FIND NRX. TIME '::ML ♦ 1£::' .-■• SPIi SET STRRT VRL FDR FIND RCTURL VRLUE 1::' TT TT = . 01 : bDSUE 3 REM PRINT COLUMN HERDS PRINT "TURNS" TRE C S::' "ELRPS ED " TRE ■:: 1 3::- " REMR I N I NG " TRE < £9::' "FEET" TRE C 35> "FEET" PRINT "COUNT" TRE':: 3::'"TIME" TRB ■:: 1 3::- " T I ME " TRE •:; £9> " USE D" TRE':: 35::' "LEFT" PRINT REM GENERRTE TRELE GDSUE 100 rem tt=trpe thickness hs=hue size ml=tdtrl trpe length mit=mr;k indic. turns MTC=MR;K RCTURL TURNS ITC=IND. CURRENT T.C. TC=RCT. CURRENT T.C. IR=RCT..-IND. RRTID RjRjL.RRDjRRERjLENGTH NXT=TDTRL TIME REM REM REM REM REM REM REM REM REM REM C:DN'v REM REM END TMjQ..TENP VRR FDR TIME Tl Fl T£ F£ TIME FEET U:i ll:" ED -.LEFT ED -.LEFT Circle 45 on inquiry card. Circle 46on inquiry card. There are two sides to our story. Side One The DISCUS7+2 Quad-Density Hardware Now you can use your S-100 system to tackle big jobs. Because the DISCUS'^ 2+2 Quad-Density Disk System puts 1.2 megabytes of fast-access memory on your side for just $1545.00 complete. With the DISCUS^" 2+2 Systerfi, complete means complete. You get a full-size (IBM- compatible 8") double-sided/ double-density disk drive, factory mounted in a cabinet with power supply, fully-buffered S-100 single-board controller, and inter- connecting cables. All fully assembled, system-tested and fully warranteed. You get the speed and efficiency of 1.2 megabyte- per-diskette memory. . . and you get itforO.ISC per byte. Side Two The DISCUS7+2 Quad -Density Software 1.2 megabyte quad-density hard- ware is only one side of the story. The DISCUS'" 2+2 System price includes all the fully-interfaced, high-performance software you need to take full advantage of your quad capacity. The system includes our exclusive BASIC-V^ virtual disk BASIC, which allows you to address your quad- density diskettes as easily as main memory The operating system you get is the widely accepted CP/M* 2.1 . And you get our powerful DISK-ATE text editor/assembler; The most advanced software development tool available. Micro-Soft BASIC 5.1 and Micro- Soft FORTRAN are available as options. Both run under CP/M* 2.1 . Check out the full system price of DISCUS^ 2+2 Quad against any other floppy disk system at your local computer store. At $1545.00, we think you'll take sides with DISCUS^ 2+2. If your dealer doesn't carry THINKER TOYS products, write MORROW DESIGNS Inc., 5221 Central, Richmond, CA 94804. Or call (415)524-2101 9-5 weekdays (Pacific Time). 9 MORROW DESIGNS/ Thinker Toys *CP/M Is a trademark of Digital Research. JoAsy one dollar bu^ about Va of a gallon of gas. Today one dollar buys 6% readers who actually your sales message. As your selling dollar buys less and less, it pays more and more to advertise in McGraw-Hill magazines. As prices keep going up and up, McGraw-HiJl magazines help 10.8 million decision-makers keep costs down. For example, Fleet Owner readers learned how they could use re-manufac- tured air cleaners to save money without sacrificing quality. And Chemical Week constantly warns manufacturers about even more government regulations. By helping 10.8 million readers solve their inflation problems, we help you solve yours. Today, the price of reaching one potential customer in McGraw-Hill magazines is only 16^.^ This compares to a cost of $6.07 for sending a business let- ter,2 over $3.50 for a business phone call,^ and an in-person sales call which, believe it or not, now costs over $100.^ In times like these, when everything costs more, you may be tempted to spend less on your advertising budget. But our Laboratory of Advertising Per- formance (LAP) Report #5262, demon- strates that "Industrial companies which maintained or increased their advertising expenditure during the 1974-75 recession enjoyed higher sales growth than those which cut advertising." Write for LAP Report #5262 today at 1221 Ave. of the Americas, N.Y., N.Y. 10020. And let us help you make your advertising more effi- cient, as the price of all other selling tools becomes more expensive. 'One reader-noted impressiin in the average McGraw-Hill publication. ^'Tlie Dartnell Institute of Business Research. ^"Telephone Marketing" by Murray Roman, P. 87, McGraw-Hill 1976. ■^Laboratory of Advertising Perfirmance Report #8013.4, McGraw-Hill Research. McGraw-Hill Magazines. m With inflation, we're an even better buy. ] Table 1: A tape counter/time table (produced by the pro- ]RUh J gram in listing 1) for a cassette recorder usi ng C-60 tape. HUB DIAMETER(INCH)? .8525 The last two columns were not pri nted by the program, but TAPE LENGTH LESS LEADER(FEET)? 303.6 are a check value from an actual test of the program's ac- TURNS COUNT AT END OF TAPE? 641 curacy. TURNS COUNT READING FOR 100 ACTUAL TAKE-UP TURNS? 77.3 1 . . . 15/16 IPS 2... 1-7/8 IPS 3... 3-3/4 IPS 4. . . 7-1/2 IPS 5... 15 IPS 6... 30 IPS WHICH TAPE SPEED? 2 CALCULATING TAPE THICKNESS AS WOUND . . . TURNS ELAPSED REMAINING FEET FEET TIME BY ERROR COUNT TIME TIME USED LEFT TEST (SEC) 00:00:00 00:32:23 304 0:00 10 00:00:19 00:32:04 3 301 0:19 20 00:00:38 00:31:45 6 298 0:39 -1 30 00:00:57 00:31:26 9 295 0:58 -2 40 00:01:17 00:31:06 12 292 1:18 -1 50 00:01:37 00:30:46 15 289 1:38 -1 60 00:01:58 00:30:26 18 286 1:59 -1 70 00:02:18 00:30:05 22 282 2:20 -2 80 00:02:40 00:29:43 25 279 2:42 -2 90 00:03:01 00:29:22 28 276 3:04 -3 100 00:03:23 00:29:00 32 272 3:26 -3 110 00:03:46 00:28:37 35 269 3:48 -2 120 00:04:08 00:28:15 39 265 4:11 -3 130 00:04:31 00:27:52 42 262 4:34 -3 140 00:04:55 00:27:28 46 258 4:58 -3 150 00:05:19 00:27:04 50 254 5:22 -3 160 00:05:43 00:26:40 54 250 5:46 -3 170 00:06:07 00:26:16 57 247 6:11 -4 180 00:06:32 00:25:51 61 243 6:36 -4 190 00:06:58 00:25:25 65 239 7:01 -3 200 00:07:23 00:25:00 69 235 7:27 -4 210 00:07:49 00:24:34 73 231 7:53 -4 220 00:08:16 00:24:07 77 227 8:20 -4 230 00:08:43 00:23:40 82 222 8:47 -4 240 00:09:10 00:23:13 86 218 9:14 -4 250 00:09:37 00:22:46 90 214 9:41 -4 260 00:10:05 00:22:18 95 209 10:09 -4 270 00:10:34 00:21:50 99 205 10:37 -4 280 00:11:02 00:21:21 103 201 11:06 -4 290 00:11:31 00:20:52 108 196 11:35 -4 300 00:12:01 00:20:23 113 191 12:04 -3 310 00:12:30 00:19:53 117 187 12:34 -4 320 00:13:00 00:19:23 122 182 13:05 -5 330 00:13:31 00:18:52 127 177 13:34 -3 340 00:14:02 00:18:21 132 172 14:05 -3 350 00:14:33 00:17:50 136 168 14:37 -4 360 00:15:04 00:17:19 141 163 15:08 -4 370 00:15:36 00:16:47 146 158 15:40 -4 380 00:16:09 00:16:14 151 153 16:12 -3 390 00:16:41 00:15:42 156 148 16:45 -4 400 00:17:15 00:15:09 162 142 17:18 -3 410 00:17:48 00:14:35 167 137 17:51 -3 420 00:18:22 00:14:01 172 132 18:25 -3 430 00:18:56 00:13:27 177 127 18:59 -3 440 00:19:30 00:12:53 183 121 19:33 -3 450 00:20:05 00:12:18 188 116 20:08 -3 460 00:20:41 00:11:42 194 110 20:44 -3 470 00:21:16 00:11:07 199 105 21:19 -3 480 00:21:52 00:10:31 205 99 21:54 -2 490 00:22:29 00:09:54 211 93 22:31 -2 500 00:23:05 00:09:18 216 88 23:07 -2 510 00:23:43 00:08:40 222 82 23:44 — 1 520 00:24:20 00:08:03 228 76 24:21 — 1 530 00:24:58 00:07:25 234 70 24:59 — 1 540 00:25:36 00:06:47 240 64 25:37 — 1 550 00:26:15 00:06:08 246 58 26:16 — 1 560 00:26:54 00:05:29 252 52 26:54 570 00:27:33 00:04:50 258 46 27:33 580 00:28:13 00:04:10 265 39 28:13 590 00:28:53 00:03:30 271 33 28:53 600 00:29:33 00:02:50 277 27 29:33 610 00:30:14 00:02:09 283 21 30:13 + 1 620 00:30:55 00:01:28 290 14 30:54 + 1 630 00:31:37 00:00:46 296 8 31:35 + 2 640 00:32:19 00:00:04 303 1 32:17 + 2 641 00:32:23 00:00:00 304 32:28 ■ 74 September 1980 © BYTE Publications Inc ■^,.,^ aneuj Is bom! #• ^^Hl^^lk. ^B^^^^^^^Hpm ^I^^^^^^^^^^^^^^^^^^^^^^^^hI »^i a better computer system any way you look at it. The facts speak for themselves. The QUAY 500 SERIES offers more for the money than North Star Horizon computers. MORE TECHNICAL FEATURES. A single board computer in- stead of a backplane with multiple boards, means fewer parts, fewer interconnections and fewer problems n additional disk capacity for more program storage D DMA controlled disk transfers for increased system performance D on-board expan- sion capabilities for additional parallel and serial ports, and EPROM D AC convenience outlets D a more compact design. IMMEDIATE DELIVERY. The 500 SERIES is available off the shelf for virtually immediate delivery. No waiting for far off de- livery dates for this one. LOWER PRICE. The advanced technology engineered into Quay computers actually lowers our cost to manufacture. The price of the 500 SERIES is about 20% lower than the Horizon-2-32K-D — and our 520 SERIES also offers significant savings over the Horizon-2-32K-Q. The bottom line is simple. There is a new star in the computer field. The 500 SERIES by Quay. It out- shines all of the competi- tion. COMPARE FOR YOURSELF: Advanced single board modular design. SPECIFICATION QUAY 500 H0RIZ0N-2-32K-D Architecture Single Board S100 bus CPU Z80A, 4MHz. Same Dynamic RAM (std/max) 32/64 Kb. Same Disk drive type Doubledensity Same No. of drives (std/max) 2/4 Same Capacity per drive (on-line) 200 Kb. 180 Kb. Direct Memory Access (DMA) Yes No CP/M® disk operating system Standard Optional Unit Price $2,500. $3,095. SPECIFICATIONS QUAY 520 H0RIZ0N-2-32K-Q Disk drive type Quad density Same Capacity per drive (on-line) 400 Kb. 360 Kb. Unit Price $3,200. $3,595. Hie QUAY 500 Offers technical superiority— availability— a $2,500 price! CP/M" is a registered trademarkof Digital Research QUA» (XDRPORATION P.O. Box 386, Freehold, New Jersey 07728 ■ (201) 681-8700 Factory: Route 34, Wall Township, New Jersey 07719 DISTRIBUTOR AND REPRESENTATIVE INQUIRIES WELCOME Circle 47 on inquiry card. BYTE September 1980 75 Circle 48 on inquiry card. SAVE MORE THAN 20% NORTH STAR — INTERTUBE — MICROTEK ZENITH — RCA-COSMAC — ITHACA THINKER TOYS — GODBOUT — SUPERBRAIN The smartest computers at the smartest price FACTORY ASSEMBLED & TESTED LIST ONLY H0RIZ0N-1-32KD0UBLE OEN 12695 11994 HORIZON-2-32KOOUBLE DEN 3095 2299 H0RIZ0N-2-32KQUAD DENSITY 3595 2699 H0RIZ0N-2-64KQUA0+HARD DISK 9329 7199 HORIZON MEMORY ASSM 16K 389 32K 579 HORIZON MEMORY KIT 16K 359 32K 535 NORTH STAR HARD DISK IB Mb 4999 3939 PASCAL FOR NORTH STAR ON DISK 199 190 Powerful NORTH STARBASICThe Best FREE 2 NORTH STAR SOFTWARE DISKS wlHORIZON FREE NSSE 1-22 &P01 TERRIFIC PROGRAMS ONLY 10 NORTHWORD 299 MAILMAN 239 INFOMAN 369 RCA-COSMAC VP-1 11 99 RCA-COSMAC VP-7 11 189 COLOR] RAINBOW 385 CAT-100 1369 SPECTRUM 2B9 ITHACA FRONT PANEL COMPUTER 64K Z-8001 CPU CARD 16 fait ITHACA S-100 8Mb ITHACA MEMORY B/1 6-bit 64K SEATTLE 80B6 CPU 16 bit 10 x fetter SEATTLE MEMORY 8/16 BIT 16K 4Mhz SSM KITS Z-BO CPU 221 VIDEO BRD VB3 4Mhz MEASUREMENT MEMORY 64K A & T 4niHz MEASUREMENT MEMORY 64K BANK SELECT ECONORAMXIVUNKIT 16K CENTRAL DATA 64K RAM DISCUS/2D A & T -^ CPfM THINKER TOYS HARD DISK 26 Mb DISCUSI2+2 1.2 Mbytes A &T TARBELL DISK CONTROLLER 00 TARBELL CASETTE INTERFACE KIT SUPERBRAIN SUPERBRAIN QUAD DENSITY 3195 2695 1179 995 845 556 356 hz 412 599 789 299 254 665 599 1199 975 4995 3995 1549 12B5 495 445 120 109 2995 2395 3995 2995 ZENITH-HEATH Z-89 48K 2B95 2495 INTERTUBE II SMART TERMINAL 995 725 ZENITH-HEATH SMART TERMINAL 995 739 ZENITH-HEATH WH 11 16bit COMPUTER 2995 CAT NOVATION MODEM 179 169 MICROTEK PRINTER 795 675 ANADEX PRINTER DP-8000 995 865 ANADEX PRINTER DP-9500-1 1650 13B9 NEC PRINTER Fast Typewriter Quality 2915 2799 SECRETARY WORD PROCESSOR The Bestl 85 77 TEXTWRITER III Book Writing Program 125 112 GOFAST NORTH STAR BASIC Speeder Uppar 79 71 PDS SUPER Z BO ASSEMBLER & Mora 99 89 SUPER BASIC DEBUGGER IB9 COMPILER 135 HOS 40 EZ-80 MACHINE LANGUAGE TUTOR 25 STATISTICS 190 EZ CODER Translates English to BASIC 79 71 ECOSOFT FULL ACCOUNTING PKG 350 315 BOX OF DISKETTES 29 IN PLASTIC CASE 30 Which Computers are BEST? BROCHURE ..FREE Noith Star Documentation refundable wfHRZ 20 ORDER 2 or more COMPUTERS . . . .BIGGER DISCOUNTS YES WE WILL BEAT OUR COMPETITION'S PRICE! FACTORY ASSEMBLED & FACTORY WARRANTY AMERICAN SQUARE COMPUTERS KIVETT DR » JAMESTOWN NC 27282 (919)-889-4577 Dissecting the TI Speak & Spell Michael A Rigsby 5164 Sunburst Dr Norcross GA 30092 There is now an economical way to provide limited voice output for computer-controlled devices. TI (Texas Instruments) provides most of the hardware in its familiar toy called the "Speak & Spell." Because I am fascinated by toys (my system is a hand-wired 1802 pro- cessor used in a self-contained, maze- solving mouse), it was only natural that I should procure my own birth- day present — a toy — and immediate- ly tear it apart. Speak & Spell is an educational aid designed for children aged seven or older. It contains a vocabulary of greater than 230 words in addition to the letters of the alphabet. Asking questions and playing games with electronic speech, it expects answers to be entered on its 40-switch key- board. Each entry evokes an audible response, and the machine even keeps score. Plug-in modules are available to expand the vocabulary. Suggested retail price for the toy is $65, though I bought mine for less than $40 at a major Atlanta department store. Operation of the electronic portion of the Speak & Spell involves many unknowns. I am sure that the manu- facturer would probably prefer to keep these unknowns secret, but I can provide some insight into the opera- tion of the Speak & Spell. The first great obstacle encountered when opening the machine is the back cover. Removing the two Phillips-head screws is a good step, but not good enough. There are still four slots, each containing a plastic hook over a plastic ledge. Take a thin-bladed screwdriver and push the hook toward the outside edge of the case, at the same time pull the front and back of the case apart with substantial force. Continue until all four hook slots are free. Take care not to allow any backsliding. I have done this three times, each time expecting to destroy it, but everything is still intact. After reaching the inside, there is not much to see except the back of a double-sided printed-circuit board. To turn the board over, the matrix switch cards (figure 1) must be re- leased from the front of the case. This involves springing delicate plastic hooks. If one of these hooks should break, the toy is lost. Somehow I slipped the cards out and turned the main board over. (See photo 1 and figure 2 on page 82.) On the opposite side of the main board are a circuit board (with a little black round thing on it) on top of the main circuit board, an 8-character alphanumeric display, and four integrated circuits, each with a distinctive proprietary number. The small circuit board appears to be a power supply. The toy operates from a 6 V sup- ply (four C cells), but +6 V, -6 V, and —20 V may be found throughout the board. The processor has five input lines from the switches; five lines seem to interconnect most of the circuits. The five input lines from the switches are activated upon contact closure by —20 V pulses generated within the processor. At this point I will refer to figure 1. Eight bits from any processor may be used to control each of thirty-two lines by means of the 74154 binary- to-hexadecimal decoder. Each output line must go to a PNP transistor capable of switching a —20 V signal. The drawing in figure 1 indicates which wires go with which letters. Text continued on page 84 76 September 1980 © BYTE Publications Inc Circle 49 on inquiry card. MCfoyyonn CALL TOLL-FREE 1-800-528-1418 SPECIALS ATARI 800 SYSTEM MicroWorld now offers complefe sysfems based around fhe Afari 800 Personal Compufer ... all peri- pherals available! The Afari 850 1 nf erf ace Module, wifh four RS232 serial porfs, an 8-bif parallel porl, and an I/O port for connecfion fo fhe Afari 800 allows for exfensive upgrading of fhe basic sysfem. Choose befween fwo prinfers: fhe Afari 820 40-column prinfer, or fhe 825 80-column prinfer, bofh packed wifh sfand- ard feafures. Afari's new 810 floppy disk drives provide up fo 92K of sforage each . . . up fo four of fhese drives may be accommodafed wifhin a sysfem! The Afari 410 program recorder wifh bofh digifal and audio frocks is used by fhe Afari Talk and Teach educafional casseffes, and by fhe Invifcfion fo Programming Ser- ies. A Bell 103/113 compafible modem is also avail- able for use wifh fhe Afari 800 or 400, allowing com- municafions wifh ofher fypes of compufers, including fime share services. The complefe line of Afari pro- ducfs,plusAfari'svasf library of applicafions software. . . all from MicroWorld! Call for Special Price! OKIDATA MICROLINE80 Compact, low-cost 80 cps printer; 9x7 matrix, friction or pin feed! 132 col. w/compressed print, graphiics, and more! Tractor feed optional. CALL FOR PRICE! CENTRONICS 737 Low-cost 50-90 cps RO printer. Pro- porlional spacing, generates full ASCII, prints sub- and superscripts, undeflinei CALL FOR PRICE! Tl 99/4 HOME COMPUTER Packed witti features! Superior sound, 16-color graptiics, power- ful Tl BASIC, optional speecti! Up to 72K total memory capacity. CALL FOR PRICE! LIVERMORE STAR Exclusive triple seal allows for superior acoustic isolation! to 300 baud, locks into standard tieadset. Full duplex/test/tialf duplex modes. CALL FOR PRICE! LEARSIEGLERADM-3A The orfgjnal "Dumb Terminal" . . . 12" non-glare screen, 24x80 dis- play. Feature direct cursor address- ing, RS232 extension port, baud rates to 19,200! CALL FOR PRICE! Tl 810 FULLY LOADED! RO printer; low price includes full ASCII, vertical forms control, com- pressed print, 150 cps, RS232, trac- tors, 3" to 15" form widtti, bidirec- tional printing] CALL FOR PRICE! ZENITH-HEATH Z-89 ALL-INONE COMPUTER Built-in minifloppy drives, smart terminal witti 25x80 display. Low price includes HDOS and 48K memory! CALL FOR PRICE! TELEVIDEO 920C Low-cost terminal loaded witti fea- tures; full-function keyboard, 24x80 display, blink, reverse, self-test! CALL FOR PRICE! B J: L X V JL3> B C D {lT> -E> vbJ ^ rCI 1rT> F {Ri> -E> ^ -E> -E> ^cn ^ I {R?> -[ir> g IC2 3 74154 BINARY-TO- 2 HEXADECIMAL DECODER 1 lis |19 Figure Ic: Using standard 74154 four-to-sixteen line decoders, the Speak & Spell can he tricked into thinking that a button has been pressed on the keyboard. The PNP transistors shown take the place of the key contacts, to short the controlling lines. Thus, the letter A can be spoken by pressing the A button, or by sending a binary 1001 on the four high-order lines to the decoder circuits; both actions short the Ll and L4 lines. 2N3906 (TYPICAL OF 16) cn CI ^i rCl Ld ^i CI CI CI VbJ rcr>" M N {L6> {LL> -Ei> -E> -E> -[R3> -[r?> -\E!> -[R6> s -{Ri> -(r?> ci:^" u lL3> -4Li> 4k!> -EE> Vb>^ — (U8> cn E> X {L9> Y {lT> {Rr> -[R8> 80 September 1980 © BYTE Publications Inc Circle 52 on inquiry card. Now! North Star Application Software! North Star now offers application software for use on the HORIZON! Now you have one reliable source for both hardware and software needs! The first packages avail- able are: NorthWord— NorthWord is a simple-to-operate word processing system designed for use with the popular North Star HORIZON. NorthWord enables you to increase office efficiency and cut document typing time and cost. NorthWord incorporates the most sought-after word processing fea- tures: easy editing, on-screen text formatting, simultaneous document printing, and much more. NorthWord can be integrated with other North Star software packages to produce customized letters, labels and reports quickly and efficiently. MailManager — MailManager enables you to com- pile and maintain complete organ- ized mailing lists. Lists are easily accessible and can be compiled with a great deal of flexibility. Entries, corrections and deletions are easily made. The North Star MailManager can printyour list on individual enve- lopes, on mailing labels, or in com- pact summary form, InfoManager — InfoManager is a powerful list- oriented, data management system. It will accept up to 50 categories of information for each record and has the ability to select and sort before printing. The North Star InfoManager has power and flexibility for many applications: product inquiry, in- ventory, customer/client records, calendar reminders, and as an easy way to fill in often-used forms. GeneralLedger — General Ledger and Financial .^ : Reporting, two programs in one. maintains general ledger accounts based on such input as checks, bank deposits and journal entries, and uses the information in the general ledger to produce custom- ized financial statements and financial reports. NorthWord is the central building block for all the North Star applica- tion software to follow. Packages now being tested include other accounting and professional appli- cation packages. For more informa- tion or a demonstration, contact your local North Star dealer. NorthStar^ North Star Computers. Inc. 1440 Fourth Street ^'^' Berkeley, CA 94710 (415) 527-6950 TWX/Telex 910-366-7001 Circle 53 on inquiry card. WHEN rr COMES FROM US, IT WORKS. 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POWER SUPPLY BOARD OUTPUT TO SPEAKER TRANSFORMER 8 CHARACTER DISPLAY PROCESSOR TMC0271NL CONNECTIONS TO LEFT HALF OF KEYBOARD LI a2 iL3 II L4 i> L5 f L6 L7 4 L8 <' 9 (-), SOUND GENERATOR TMC0281NL UNKNOWN #1 (HIGH-DENSITY READ-ONLY MEMORY) TMC0351NL KEYBOARD ATTACHMENT UNKNOWN #2 (HIGH-DENSITY READ-ONLY MEMORY) TMC0352NL CONNECTIONS TO RIGHT HALF OF KEYBOARD Rl tR2 R3 R4 4 R5 R6 KEYBOARD ATTACHMENT- SOCKET FOR PLUG-IN MODULE O i(+) SPEED POTENTIOMETER (CLOCK CONTROL) R7 Figure 2: Layout of the Speak & Spell main circuit board, viewed from the front of the toy. The new microcomputer FORTRAN you'll be proud to take anywhere. Microcomputer users like you want the best of all worlds. A single development and run-time system that can support FORTRAN on hundreds of thousands of systems ... a standard FORTRAN that is available immediately for whatever micro you have. . . plus the power, portability and completeness of the UCSD™ System. Impossible? It was until now. 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Call or write for more information; Master Charge or Visa orders accepted. n suBsitDif^nv or softech 9494 Black Mountain Road, San Diego, CA92126. (714] 578-6105. You've got your choice with UCSD™ System Software. Use it on microcom- puters with CP/M, or on any system using a Z-80. 8080/8085. LSI-11 J^ 6502. 6800, 6809. or 9900 microprocessor. D Send me the Complete set of UCSD System documentation including the FORTRAN and Pascal languages. My check or money order for $50 is enclosed. $50 D Send me more information about the UCSD System with FORTRAN D Send me more information about the UCSD System with Pascal D Send me more information about the UCSD System with both FORTRAN and Pascal D Send me Distributor information Name Company.. Address City/State/Zip ^_ Telephone Massachusetts and California residents add applicable sales tax. CM-17E-(5/80) CP/M "•' is a registered trademark of Digital Research Corporation. LSI-11 is a registered trade- mark of Digital Equipment. UCSD Pascal and UCSD are registered trademarks of The Regents of the University of California. Circle 54 on inquiry card. BYTE September 1980 83 COMPLEX SOUND GENERATOR ENVELOPE SELECT 1 (INPUT) GROUND EXTERNAL NOISE CLOCK (INP.) NOISE CLOCK RESISTOR (INP.) • NOISE FILTER CONTROL RESISTOR (INR) ■ NOISE FILTER CONTROL CAPACITOR (INP.) DECAY CONTROL RESISTOR (INR.) ATTACK/DECAY TIMING CAPACITOR (INP.) ■ SYSTEM ENABLE (INP.) ■ ATTACK CONTROL RESISTOR (INP.) - AMPLITUDE CONTROL RESISTOR (INP.) ■ FEEDBACK RESISTOR (INP) • AUDIO OUTPUT - VCC - SN76477N 1* *28 2 *27 3 *26 4 *25 5 24 6 23 7 *22 8 21 9* 20 10 19 11 18 12 17 13 16 14 15 -ENVELOPE SELECT 2 (INPUT) -MIXER SELECT C (INP.) -MIXER SELECT A (INP.) -MIXER SELECT B (INP.) -ONE-SHOT CONTROL RESISTOR (INP.) -ONE-SHOT CONTROL CAPACITOR (INP.) -VCO SELECT (INP.) -SUPER LOW FREQUENCY OSC. CONTROL CAP. (INP.) -SUPER LOW FREQUENCY OSC. CONTROL RES. (INP.) -PITCH CONTROL (INP.) ■VCO CONTROL RESISTOR (INP.) -VCO CONTROL CAPACITOR (INP.) -EXTERNAL VCO CONTROL (INP.) -V REG. Figure 3: Pin assignments for the SN76477N complex-sound generator. It is suspected that this well-known device is marked TMC0271NL in the Speak & Spell. The pins marked with asterisks are in a logical low state unless they are pulled up by an external voltage. Behavior Pin # of TMC0271NL Connected To Pin Device # Informal Name steady pattern when letters are pronounced, variable pattern for all words 22 25 27 4 11 14 TMC0351NL TMC0271NL TMC0271NL Unknown # Processor Processor variable pattern for all speech 26 28 6 36 TMC0351NL TMC0271NL Unknown #1 Processor Table 1: Experimental behavior of selected logic lines coming from the TMC0271NL device on Speak & Spell circuit board. Text continued from page 76: while figure 2 shows the location of these wires in the toy. Each line must be released before the processor will accept another input command. Returning to the operation of the device, the 40-pin circuit is undoubt- edly a processor. There are two inte- grated circuits which I have labeled as high-density read-only memory (however, this is only a guess). They contain the information for the 230 spoken words; the processor (TMC0271NL) appears to contain the spoken letters and a few brief words. Of the forty pins on the processor, five are input lines from the switches, seven are pulsed output lines to the switches, fifteen or more are output lines to the display, and three are out- put lines to the sound generator. Three of the lines that go to the display are part of the five lines that connect the processor to unknown circuit #1 (mentioned above as possibly being a high-density read- only memory). If the unknown cir- cuits are memory devices, the in- dividual byte locations are not ad- dressed by the processor (there is an insufficient number of interconnect- ing lines for that purpose), but are possibly left to be sequenced by a clock and stopped by processor con- trol. I am reasonably certain that the sound is generated by a complex sound generator, SN76477N. This circuit is controlled by numerous resistor-capacitor combinations and seven digital-control lines. (See figure 3 and table 1.) If this device is the chip marked TMC0271NL in the Speak & Spell, then it is two of the seven con- trol lines (pins 1 and 9) that are tied to ground all of the time. Five of the lines have varying signals, though three of these maintain a constant pattern when letters are being pro- nounced. The narrowest spike in a pulse train that is connected to a con- trol line is 0.1 ms long. With a 230-word vocabulary, there is a con- trolled speech time of well over 100 seconds. Five lines multiplied by 100 seconds multiplied by 10,000 pulses per second yields 5,000,000 bits of in- formation stored somewhere in the Speak & Spell — providing one assumes that each word is composed of individually stored pulses. There are probably subroutines that cause the production of phonetic elements. I can see no way to access these phonetic elements, because they seem to be internal and not directly ad- dressable by normal address lines. Someone with more memory than I have (1 K bytes of user memory) could monitor the control lines on the sound generator (see figure 3) and perhaps determine the phonetic makeup of individual sounds. If you don't mind listening to your computer spell everything, give it a voice and let it speak. ■ 84 September 1980 © BYTE Publications Inc MAKES CP/M EASY AS ABC CP/M-the industry standard in operating systems: now Sybex makes it easy as ABC with a new step-by-step guide: THE CP/M® HANDBOOK (with MP/Mtm). Gain a clear understanding of CP/M's basicoperation, learn how to use the editor and assembler, then explore all versions of CP/M, including CDOS and multi-user MP/M. Numerous sample programs, practical operating hints and handy reference tables make the CP/M HANDBOOK a must for anyone-from beginner to experienced programmer. For sophisticated editing or simple copying, the new CP/M HANDBOOK gives you a hand-and makes CP/M easy as ABC. By Rodnay Zaks, 250 pp., Ref. C3CX>, $13.95 CP/M* and MP/M ^^ are trademarks of Digital Research Circle 55 on inquiry card. Dept. B9 2344 Sixth St. Berkeley, CA. 94710 AVAILABLE AT BOOKSTORES AND COMPUTER SHOPS EVERYWHERE TO ORDER: By Phone: (415) 848-8233, Visa. MC. Am Ex By Mall: Indicate quantity. Prepayment required Stilpping: S1.50 per book (UPS) or 75c (4th Class) Tax: In California please add tax MAIL TO: SYBEX 2344 Sixth St., Berkeley, CA 9471 Send me copy(s) of The CP/M Handbook @ SI 3.95 Name Company. Address City _Zip_ Amount enclosed _ Charge my D Visa Card number Expiration date . Signature D UPS D 4th class D Master Charge n Am. Ex. n Send me your free catalog C300B9 Penny Pincher's Joystick Interface Steven Wexler 1634 Buck Hill Dr Huntingdon Valley PA 19006 One of the more entertaining input devices that can be operated by a human hand is the joystick. Physi- cally, the device consists of a lever that moves in two dimensions. The lever operates two potentiometers, which translate the position of the lever into two analog resistance values. A joystick hardware inter- face, in conjunction with the ap- propriate software, can convert the resistance values into corresponding binary integer values. These integers can be used to move a cursor, alter music, or control a robot, along with a myriad of other applications. There are several ways to interface a joystick to your computer. Each scheme has its advantages and disad- vantages. The particular method I have chosen has the advantages of be- ing inexpensive, easy to build, easy to understand, and of requiring a minimum of input/ output (I/O) pro- gramming. The disadvantages? This method is slower than some other interfaces I have seen, uses more software than do the expensive hardware-intensive schemes, and is less precise than some of the more elaborate circuit concoc- tions. Operating Theory The key to my "penny pincher's" joystick interface is the 556 dual timer configured as two monostable multi- vibrators or one-shots, as shown in figure 1. In English, this means that if you trigger the one-shot, its output will go high for a predetermined in- terval, after which the output will return to its normal low state. By using a joystick potentiometer as a timing resistor, the duration of one output pulse will be proportional to the position, in one dimension, of the joystick lever. Software is used to convert the pulse duration into a binary value. Duplicating the circuit for the second timer, the other joy- stick potentiometer will yield a dif- ferent output-pulse duration and binary value for the other dimension. Remember, joysticks operate in two or more dimensions. Joystick Interface Circuit Careful study of figure 1 will reveal a most curious aspect of the interface. The trigger and reset lines for each circuit are all tied to a common pro- cessor output line. This certainly saves output lines, but how can you trigger and reset simultaneously? An explanation of the trigger re- quirements for the timer circuits should help to clear up this anomaly. Normally, the timer will start to output a pulse on the high-to-low transition (ie: negative-going edge) of the input trigger signal. For the device to work properly, it is necessary to return the trigger input to its normal high state before the timed-output pulse returns low. In other words, before the device times out, the trig- ger input must go high. If the timer receives a trigger signal in the middle of an output pulse, the signal is ignored. The obvious conclu- sion is that we must either trigger each of the 556 timers independently, or we must reset the second timer before it is triggered. Otherwise, how are we to avoid attempting to trigger the second timer before it has timed out from the initial signal? Tying the resets and triggers to a common computer-output line avoids the tim- ing pitfall, while simplifying both hardware and software. When the computer-output line goes low, the timing function is reset and the device returns to its initial state. As the processor-output line returns high (ie: positive-going edge), the circuit is reset before it is trig- gered; this allows the timing pulse to begin normally. The I/O line used to reset and trigger the 556 can also be used to reset and trigger additional joysticks. How's that for efficiency! I have not included the values of the timing capacitors and potentiometers 86 September 1980 © BYTE Publications Inc For years many small business system buyers thought that in order to get "real" performance and enough storage to be a "real" business system they would have to sacrifice the family jewels. But with the introduction of the Smoke Signal Chieftain series office computers a lot of people's minds have been changed. Because we designed the highly reliable Chieftain small business system with the most innovative combination of performance and effi- ciency around. At your fingertips there are 64,000 characters of random access memory and you can address anywhere from 740,000 characters to 2 million characters with Smoke Signals's new double den- sity controller. For larger concerns, there's a 20M byte hard disk available. At a time when other small computer manu- facturers tell you "you're on your own". Smoke Signal offers an abundance of easy-to-use software programs such as order entry, inventory control. accounts receivable, invoice entry, payroll, word processing and much, much more. There's BASIC, COBOL and FORTRAN — even a multi-user BOS (Business Operating System) that allows for numerous users simultaneously. Chieftain systems starting at under $200.00 per month display per- formance on par with sys- tems costing twice to three times as much. So call (213) 889-9340 for your nearest autho- rized Smoke Signal dealer demonstrate the Chieftain*s high reliability and ease of operation. For dealers only, circle 57 All other inquiries, circle 56 he'll be glad to SHOEESIOHIL BKOSKBSTINB 31336 Via Colinas. Westlake Village. California 91361, (213) 889-9340 TRIGGER FROM PROCESSOR OUTPUT STROBE 5V 4 >1K >1K TO PROCESSOR^ — ,_ INPUT LINE "A"*^— ^ TO PROCESSOR ^--t_ INPUT LINE "B" "^-—^ 10 TIMING CAPACITOR 8 RESET TRIGGER RESET TRIGGER DISCHARGE THRESHOLD OUTPUT ICl 556 DISCHARGE THRESHOLD CONTROL VOLTAGE CONTROL VOLTAGE Number Type +5 V GND 1C1 556 14 7 :o.oi/iF ■9h 1 r JOYSTICK POTENTIOMETER A I-5V <^JOYSTICK /f POTENTIOMET B 12 /77 ER /77 :o.oi^F •TIMING ' CAPACITOR B ;o.oi^F Figure 1: The key to the penny pinchers joystick interface is the 556 dual timer, configured as two monostahle multivibrators. The in- terval of each output pulse is determined by the joystick resistance, in conjunction with a user-selected timing capacitor. FINALLY! ONE ASSEMBLER -^'C'T" BY SORCIM - LETS YOU ASSEMBLE CODE FOR 6502, 6800, 8080, 8085, AND Z80 In use for two years by Sorclm to facilitate program development, the A.C.T. (Assembly Code Translator) "universal" cross-assembler supports all 5 major processors and is now available to the public. Get out of writing hex and toggling switches; A.C.T. gives you efficient programming as well as the capability to develop code for one processor on a machine using a different Drocessor. Running under CP/M* 1.4X or 2.X, A.C.T. features; • Assembly speed greater than 1000 lines/min © Complete cross reference • Support for data type hex, octal, or binary (Intel or Motorola format) • Supports macros • Comprehensive set of pseudo-ops • Absolute assemblies, system text file support, local proc definition (8080/5 & ZBO only), code file format (standard Intel hex), and many more special features. A.C.T. fits in 24K of RAM (including CP/M), comes complete with manual and sample programs, and is shipped on a single-sided, single density, soft-sectored CP/M compatible 8" diskette. Want to know more about A.C.T.'s many talents? The manual is available separately for $15. SORCI/M PO Box 32505 SAN JOSE, CA 95152 How to order: We accept UPS COD, Mastercard® , VISA" , personal checks, and certified checks. Califor- nians add sales tax. Add 510 outside USA. ALSO AVAILABLE FROM SORCIM FOR $175: PASCAL/M'^ THE LOW-COST/- HIGH PERFORMANCE LANGUAGE FOR ALL Z80/8080/8085 COMPUTERS. 'CP/M is a trademark of Digtlal Research A.C.T. and PASCALM are trademarks of Sorcim. in figure 1; these values depend on software, processor speed, and per- sonal preference. Software The software needed for the penny pincher's interface is very straight- forward. The 556 timers are triggered by setting the proper computer- output line first low, then high. After this, the processor should enter a tight, time-efficient counting loop until one circuit times out. The soft- ware should immediately store the count and then start the process over for the next timer. It is recommended that you disable interrupts during the counting process; otherwise an inac- curate count may occur. Listing 1 presents the joystick- driving software for my KIM-1 com- puter (6502 processor). The program assumes that the reset/trigger line is tied to the KIM-1 I/O line Bl. The timer's outputs are tied to B2 and 33; a second joystick may be tied to lines B4 and B5. Utilizing consecutive I/O lines in this manner allows for efficient I/O line polling by merely shifting an I/O mask. Figure 2 is a flowchart of the 88 September 1980 © BYTE Publications Inc Circle 58 on inquiry card. i^isi INHKHMNINb VIDEOPraifr: Hie picture perfect peripheral. Videoprint is the convenient economical means of obtaining distortion-free line or continuous tone hardcopy from raster line computer graphics displays in full, brilliant color The entire system is self contained in the convenient desk-top unit shown above. Videoprints eliminate such off-the-screen photography problems as barrel distortion, color de-saturation and loss of color fidelity. Videoprints also minimize the effects of raster lines and video noise. Videoprints are instantly produced with Polaroid® SX-70orPolacolorf' x5" films, as well as with conven- tional color negative or 35 mm slide transparency films, offer- ing you a range of handy sizes. The pictures can be made by untrained personnel at the push of a button. If you Ve ever wanted to distribute copies of computer graphics or TV video stills or file them in your permanent records, or send them through the mail or project them as slides, you need Videoprint. If you Ve ever wanted to document alternatives in an interactive graphics process, or monitor periodic events without 24-hour observation, you need Videoprint. In fact, if you use computer graphics in any form, you really need Videoprint. Find out all about this exciting new tool. Write or call us today. Circle 59 on inquiry card. The Videoprint People. Image Resource Corporation 2260 Tnwnsgate Road, Westlake Village, CA 91361 (805)496-3317 "Polaroid',' "Polacolor"ancl "SX-70" are registered trademarks of the Polaroid Corporation. (JzD f JOY 2 j INITIALIZE FOR 1 JOYSTICK INITIALIZE I/O PORTS, TIMER POINTER SAVE INTERRUPT DISABLE STATUS DISABLE INTERRUPT INITIALIZE COUNTER TO ZERO RESET AND TRIGGER TIMERS UPDATE TIMER POINTER RESTORE INTERRUPT DISABLE STATUS f RETURN j INITIALIZE FOR 2 JOYSTICKS Figure 2: The joystick-driving software consists mainly .of a counting loop; this determines the stick position by timing the output pulse interval. High resolution can be attained by using a fast counting loop. Listing 1: The software used on the auth jr's KIM-1 system resets the interface timers with a low logic state on I/O line Bl. When the same line goes high, the timers are || retriggered. This technique, using only one output line, contributes to the simplicity \ of the hardware. POT = $17E3 POT 1, Y AXIS POT + ] = $17E4 POT 1,X AXIS POT+: ?=$17E5 POT 2, Y AXIS POT + : J=$17E6 POT 2, X AXIS PBD2 = $1702 PORT B DATA REGISTER PBDD2 = $1703 PORT B DIRECTION REGISTER 8510 A2 01 JOY LDX jf\ ENTRY FOR ONE JOYSTICK. 8512 DO 01 BNE HOP FORCED JUMP. 8514 A2 03 JOY2 LDX jif3 ENTRY FOR TWO JOYSTICKS. 8516 A9 02 HOP LDA jif2 INITIALIZE TIMER POINTER. 8518 8D 03 17 STA PBDD2 SET LINE Bl FOR OUTPUT, REST INPUT. 851B 08 PHP SAVE INTERRUPT STATUS. 851C 78 SEI DISABLE INTERRUPT. 851D OA LP ASL UPDATE TIMER POINTER. 851E AO 00 LDYj^fO TRIGGER TIMER VIA 8520 8C 02 17 STY PBD2 LOW TO 8523 AO 02 LDYji(2 HIGH TRANSITION 8525 8C 02 17 STY PBD2 OF LINE Bl. 8528 AO FF LDY ilFF INITIALIZE COUNTER. 852A CA LPl INY UPDATE COUNT. 852B 2C 02 17 BIT PBD2 TEST TIMING PULSE. 852E DO FA BNE LPl IF HIGH, CONTINUE COUNT. 8530 48 PHA 8531 98 TYA 8532 9D E3 17 STA POT,X SAVE COUNT. 8535 68 PLA 8536 CA DEX 8537 10 E4 BPLLP MORE TIMERS? 8539 28 PLP NO, RESTORE INTERRUPT STATUS. 853A 60 RTS program. Remember to keep the counting loop as efficient as possible. Calibration The count we obtain from the in- terface is equivalent to the duration of the timing pulse divided by the processing time required by the com- puter to execute one counting loop. My 6502 system, running at a clock frequency of 1 MHz, will execute the counting loop in listing 1 (hexa- decimal 852A thru 852E) in 9 fis. It stands to reason that if you want a joystick to read from to 100 on this machine, you would choose a poten- tiometer and capacitor that would set the maximum duration of the timing pulse to 909 /IS (101 X 9 /is). The following formula is used to derive the value of the timing capacitor: C = pulse duration l.lXi^ where C is in farads, duration is in seconds, and R is in ohms. Assuming a joystick with 100 k-ohm poten- tiometers, a 0.0083 /iF capacitor is needed to produce a 909 /is timing pulse. Since the actual value of most capacitors is not precisely known, it may be desirable to trim the maxi- mum timer intervals. This can be done by placing extremely small- value capacitors in parallel with the main timing capacitor of the circuit that has the smaller maximum pulse of the two. Silver mica capacitors should work well here. Construction The circuit is quite simple and compact. With point-to-point wir- ing, several joystick interfaces can be constructed on a small circuit card. Placement of components is not critical. Each interface should draw less than 40 mA from a + 5 V supply. Surplus joysticks can be purchased for about $4, while the 556 timer costs less than $1; so, for about $6 and one night's work, you can add this joystick interface to your system. ■ 90 September 1980 © BYTE Publications Inc Apple vs IBM IBM/370 users have VSAM (Virtual Storage Access Method) to provide fast, flexible keyed-access to their data. Now KRAM (Keyed Random Access Method), from United Software of America, gives APPLE users the same flexibility, substantially increasing the processing power of the APPLE. Until KRAM, the only "random access" capability in the APPLE consisted of a crude form of "relative record" processing. While this is usable for very simple applications, it falls far short of the needs of today's business & analytical applications. Using KRAM, records may be processed by a "key" value, which may consist of any kind of data: numbers, letters, special characters, etc. Even APPLE'S long-awaited DOS 3.3 doesn't have anything like this!! Just compare; Consider an employee file in a Payroll application: APPLE'S DOS 3.3 FUNCTION RANDOM ACCESS KRAM FEATURES Retrieve by Social Sec. # NO YES Relative record is limited to 7 digit #'s; KRAM keys up to 48 bytes! Retrieve by Last Name NO YES Relative record cannot file alphabetically Erase a record NO YES Relative record cannot erase records Dynamic record allocation NO YES KRAM files grow as needed Dynamic compression NO YES KRAM recaptures space when records are deleted Mutliple files open NO YES KRAM can keep 5 files open simultaneously BEST WAY NO YES It's obvious As you can see, KRAM nowattains levelsof sophistication ontheAPPLE that rival those of IBM mainframes. . . So why let the IBM users have all the power? Power up your APPLE with KRAM! KRAM RELEASE 2.0 FUNCTIONS: • Create/Open a dataset • Put record by key • Add & Delete records by key • Get any record by Full or • Partial key in .4 sec. • (.2 sec. with Corvus Disk) Supports multiple disks Read next or previous record Dynamic space allocation Dynamic space reclamation Dynamic index compression Never needs reorganization An 80 page manual fully documents KRAM 2.0 functions and illustrates with programmingsamples. KRAM architecture isfully explained and asample mailing list application program is included. APPLE 8f PET Requirements: KRAM is designed to work with both APPLE'S Disk 1 1 and Corvus Systems 10 Megabyte Winchester Disk, and Commodore's 2040, 3040, and 8050 Disk units. KRAM 2.0 requires 32K/48K APPLE with Integer Basic in ROM (compatible with APPLESOFT) and at least one disk drive. KRAM works on any 40/80 column 16K/32K PET. 3?®(SLm©1^®iPf' ^p(S©isiIL $99*95 750 3RD Avenue, New York NY 10017 (212) 682-0347 UNITED SOFTWARE OF AMERICA Telex 640055 Look for the RED-WHITE-BLUE United Software Display at your local computer dealer, or send check or moneyorder, plus $3.00 shipping to: DEALER INQUIRIES INVITED Biologically based paradigms provide insights into artificial intelligence. As researchers begin to unravel the mysteries of the brain's chemical, elec- trical and synaptic cir- cuitry their findings are becoming immediately ap- plicable to advances in robotic behavior and com- puter design. Ernest W Kent, a computerist and professor of both physio- logical psychology and psychopharmacology, dissects the brain to create biologically based paradigms providing new insights into computer design and artificial intelligence. Professor Kent has written one of those rare and important works that transcends previously perceived disciplinary boundaries. The ever- increasing relationship between man and machines is freshly ex- amined; a relationship, Professor Kent concludes. that more and more is be- ing modeled after man's own neurological self ""^^9®- B|iTE This and other B>TE/McGraw-Hill books are available from BYTE BOOKS or your local computer store. The, ^ Brains of M , and Machine by Ernest Kent 70 Main St. Peterborough. NH 03458 ISBN #0-07-034123-0 Price $15.95 Please remit in U.S. funds or draw on a U.S. Bank Please send u . copies of The Brain $ of Men and Machines Name Title Company Street City State/Province Code Check enclosed in the amount of $ Bill Visa D Bill Master Charge Card No Exp. Date »^^_ Add 75(E per book to cover postage and handling. BY 9 Available at the end of October 1980. The best in data base management for your micro-computer Get the most out of your micro-computer. Use our advanced and progressive data management system. HDBS is an extended hierarchal data base system ottenng • fixed length records • file-level read/write protection • one-to-many set relationships MDBS is a full network data base system offered as an upgrade from HDBS. . .or it may be ideal as your initial system. Unique and versatile, it adds these features: • full network CODASYL-oriented data structures • variable length records • multiple levels of read/write protection • one-to-one, many-to-one, and many-to-many sets • non-redundancy of data, easy updating • occurrences of a record type may own other occurrences of the same type • a single set may have multiple owner and member record types MDBS-DRS. As an add-on to MDBS, the DRS system offers extraordinary flexibility in data base restructuring to meet new needs. • Item, record, and set types can be added, deleted, or renamed in an existing data base as well as other data base characteristics. You can redesign the data base after it is already on-line! MDBS-RTL. As an add-on to MDBS, the RTL (Recovery Transaction Logging) logs all data base transactions, so that in the event of a system failure, the data base can be recovered with minimal loss of information. • The recovery proeessor permits selective reloading of the data base from the transaction file. Users can log messages, indicate complex transaction sequences, and effect selective control over the recovery process. MDBS-QRS. An interactive Report- Writer/Query-System for HDBS/MDBS data bases. Features.. . • may be customized for non-technical users • complex retrieval conditions may be specified • detailed reports can be quickly generated • wildcard and "matoft-one" string specifications included MDBS and MDBS Packages Include: • DDL data definition language analyzer/editor • 260-page users manual • DMS data management routines callable from host language • Sample application program and DDL files • Relocatorto re-org all routines • System specific m'anual for bringing up our soYtwar^e Coming soon: Multi-User Versions of MDBS, and a Z8000 Version. : A PRiMER ON DATA BASE MANAGEMENT SYSTEMS -i-Sr- ! o "(3 p «.„»-.«-,. .-. ... 54-page "primer" on data base systems for micro-computers — only $10.00 per copy. Both HDBS and MDBS Systems. • Run under. . . CP/M with Microsoft BASICS. FORTRAN or COBOL; InterSystem PASCAL/Z; Sorcim PASCAL/M; Micro Focus CIS COBOL; Digital Research PL/I MVT/FAMOS with BASIC OASIS with BASIC TRSDOS and NEWDOS (Models I and II) with Disk BASIC North Star DOS with North Star BASIC Apple DOS and Applesoft BASIC Machine Language Interface available on all above systems. • Up to 254 record-types definable in the data base; each record-type may contain up to 255 item- types; each item-type may be up to 9,999 bytes in length. • Names of data items, records, sets, and files are wholly user definable. • Commands to add, delete, update, search, and traverse the data base. • Straightforward use of ISAM-like structures. • Records can be maintained in several sorted orders. • Written in machine language for maximum execution efficiency and minimal memory usage. • Independent of types and sizes of disk drives. Support data base spread over several disk drives (max. 8); disks may be mini- or full-sized floppies or hard disks. • Available versions: Z80 (requires approx. 18K), 6502 (approx. 26K), 8080 (approx. 22K) Total memory requirement must allow for buffer areas. • 8086 version available. (Call or write for details and prices.) Ordering and pricing information: (applicable to Z80, 8080 and 6502 versions): HDBS $ 300.00 When ordering, specify intended MDBS 900.00 use with... DRS 300.00 1. North Star DOS and BASIC RTL 300.00 2. CP/M - Microsoft BASIC 4.XX QRS 300.00 3 CP/M -. Microsoft BASIC 5.XX HDBS upgrade to MDBS 650.00 4. CP/M- Microsoft BASIC MDBS with DRS. Compiler or FORTRAN- RTL. and QRS 1500.00 80 HBDS/MDBS Manual 35.00 5. CP/M - Microsoft COBOL-80 DRS Manual 5.00 6. CP/M - InterSystem PASCAL/Z RTL Manual 5.00 7. CP/M - Sorcim PASCAL/M QRS Manual 5.00 8. CP/M - Digital Res^earch PL/I System Specific 9. CP/M - Micro Focus CIS Manuals (each) 5.00 COBOL 10. TRSDOS/NEWDOS and TRS Within a given operating system. Disk BASIC (Models 1 and II) add $125.00 for each additional 11. Apple DOS and Applesoft BASIC language selected. 12. MVT/FAMOS and BASIC * 13. OASIS and .OASIS BASIC For prices outside the U.S. and Canada, please ask for price lists. 14. Machine Language Programs (Specify operating system.) Add $2.50 handl ing fee for non-cash Indiana residents add 4%. order (S5.00 outside U.S.). We accept Visa and Master Charge. Finally, our software mdy cost a litjile more. . . but it's worth a lot more in quality and versatility. iWlicrc Dutu Base Systems, Inc. Box 248, Lafayette, Indiana 47902 317-742-7388 or 317-448-1616 Circle 60 on inquiry card. BYTE September 1980 93 lat^usges FoMNfi Pascal and the Great Race David A Mundie, 104 Oakhurst Cir, Charlottesville VA 22903 I have some comments on the record maintenance techniques described in "The Great Race and Micro Disk Files," by J J Roehrig (April 1980 BYTE, page 142). Mr Roehrig's initial method took almost a minute just to write 120 real variables, so it is little wonder that he began looking for a better way. His decision to minimize disk transfers by not sorting the records on the disk seems eminently sensible. However, his other decision, to read and write individual elements of the array instead of using a FOR... NEXT loop is lamentable. Surely there is something wrong with a language so inefficient that loops are prohibitively slow. One wonders what he would have done had there been 1000 elements in the array rather than twelve. Mr Roehrig might consider changing programming languages as a solution to his problem. The root of his difficulty is that BASIC does not allow for files of arrays (or any other structured data type, for that matter). In Pascal, it would be possible to define SCRATCH as a file 779 UPPER CASE/lower case "Conversion Kit I" Expand the capabilities of your 779 line printer to include word processing!! Available to all Centronics 779/TRS 80 Printer I owners is the option of lower case and changing slash zero to standard 0. No etch cuts or soldering needed. Installs in minutes with a screwdriver. No program modification or additional interface is required. Price $125.00 Motor control 'XON VERSION kit ir FOR ALL CENTRONICS 779/TRS 80 PRINTER I UNE PRINTERS!! Our "Conversion Kit ll" Motor Controller gives your 779 the ability to turn the motor on and off automatically. Removes the annoying noise of constant run, increasing the life span of your 779 / TRS 80 line printer motor! No soldering, software or hardware changes needed. Installs easily. Price $95.00 SAVE! Buy Sen/ice Technologies "Conversion Kit I" and "Conversion Kit ll" together for the single price of $199.00 To order, please send check or money order in the proper amount to: r , 7^ / / . d iJervice Jecnnoloqtes, Jjnc. 32 Nightingale Rd. Nashua, N.H. 03062 (603) 883-5369 Visa and Master Charge accepted (please include signature, expiration date and phone number) Sen/ice Technologies will pay all shipping and handling. of arrays of reals, with twelve reals in each array. Writing an array is then accomplished by the simple statement PUT(SCRATCH), while reading is done by GET(SCRATCH) — no loops, and especially no referenc- ing of each element of the array. Listing 1 PROGRAM RACETEST; CONST DUMMYVALUE = 1.23456; TYPE REALARRAY = ARRAY[1..12] OF REAL; VAR IJ: INTEGER; DUMMY: REALARRAY; SCRATCH: FILE OF REALARRAY; PROCEDURE CLOCK; BEGIN WRITELN (^CLOCK: '); READLN END; BEGIN (*RACETEST— MAIN PROGRAM*) FOR I := 1 TO 12 DO DUMMY[I1 := DUMMYVALUE; CLOCK; REWRITE (SCRATCH, ^SCRATCH'); FOR I := 1 TO 10 DO BEGIN SCRATCH! := DUMMY; PUT (SCRATCH) END; CLOCK; FOR I : = 1 TO 5 DO BEGIN RESET (SCRATCH); FOR I := 1 TO 10 DO BEGIN DUMMY := SCRATCH 1; GET (SCRATCH) END; END; CLOCK; CLOSE (SCRATCH) END. A Pascal program equivalent to his program is given in listing 1. Because ten arrays of twelve reals do not fill up the minimum UCSD Pascal buffer of 512 bytes, for benchmarking purposes I actually used an array size of 120 real variables, then divided the execution times by 10. This yields a time of about 0.4 seconds to write ten records, compared to Mr Roehrig's minimum of 3 seconds, or the estimated 20 seconds using loops. Reading ten records five times took about 1 second, com- pared to his minimum of 6 seconds. Part of the difference may be attributable to hardware (I used a Pascal Microengine with double-density 8-inch disks), but I am convinced that the difference is largely due to Pascal's more rational handling of files. In this case, at least, higher-level constructs seem to be not only easier to use, but also more efficient than those at a low level. ■ 94 September 1980 © BYTE Publications Inc Circle 61 on inquiry card. Circle 62 on inquiry card. Hard and Fast... ...Bulk Storage from Industrial Micro Systems THE NEW MODEL 16 The new Industrial Micro Systems Model 16 Hard Disk Subsystem is a "fixed-removable'' high speed, bulk storage device providing from 32 megabytes (32 million characters) to 96 megabytes of on-line storage for the Industrial Micro Systems 8000 or Series 5000 microcomputer systems. The Model 16 includes a credenza enclosure that provides a quiet, strong and attractive package for office or industrial applications where large memory is required. The Model 16 also includes a fully buffered DMA S-100 bus controller for fast and easy interfacing. WINCHESTER TECHNOLOGY WITH BUILT-IN BACKUP The Model 16 includes a 16 megabyte removable cartridge and a 16, 48, or 80 megabyte fixed media that employs Winchester 3340 technology. Files and programs may be copied between the fixed media and the removable cartridge for fast, easy backup and archival storage. FAST ACCESS The interface between the Model 16 hard disk and the Industrial Micro Systems computer is provided by the Hard Disk Controller. The Hard Disk Controller utilizes Direct Memory Access (DMA) for fast data transfer with minimum processor interven- tion. The maximum data transfer rate is 1.2 megabytes per second and the controller fully buffers the data, a sector at a time, to and from the disk. Available in 220 V, 50 HZ Versions Now you don't have to look hard for fast computing power. Contact your Industrial Micro Systems Dealer today. INDUSTRIAL MICRO SYSTEMS Marketing 628 N. Eckhoff, Orange, CA 92668 (714) 978-6966 Manufacturing 2800 Lockheed Way, Carson City, NV 89701 (702) 883-7611 I^nical Umm The article "A Power-Line Protectio}i Circuit" by Neil ScJuicider aiui Br or Ericksoii (March 1980 BYTE, page 126) geyierated a great deal of corresf-uvhience. Tiiis iiichnicii the foUowing criticistii In/ Mr Newswa}iger a}ui the circuit offered by Mr Scliafcr. Protection Circuits Donald W Newswanger, Dept of Building and Safety, City Hall, Rm 485, Los Angeles CA 90012 I was disappointed to see the article "A Power-Line Protection Circuit" (March 1980 BYTE, page 126). No direct internal connection should ever be made to a hot- chassis transformerless television set. The antenna ter- minals may be safely used with a suitable RF (radio- frequency) modulator, but no attempt should be made to connect directly into the video circuit. Transformer- isolated television sets and monitors are readily available for this purpose. The circuits in both figure 1 and figure 2 of that article introduce problems into the building wiring system. The use of either circuit will trip a ground-fault circuit breaker. Circuit 2 is particularly bad since it directly in- terconnects the ground wire and the neutral during nor- mal operation. The neutral conductor of a two-wire cir- TRS-80 MOD II WORD PROCESSING QiUipDaisv WORD PROCESSOR The best is now even better. . New Features New Commands New Capabilities New Manual SPECIAL PACKAGE INCLUDES: • Wp Daisy^"" word processor • Mail Merge'" mailing list package • I/OS operating system full CP/M'" & CDOS compatability Includes — Diablo, Spinwriter and Qume support — Printer spooling — 30 programs CP/M'" TM of Digital Research cuit carries the same current as the hot wire of the circuit. The interconnection of the neutral and ground wire will cause part of the normal neutral current from aJJ ap- plicances connected to the circuit to flow through the ground wire. The ground wire is intended to provide a ground path for appliances and should never be used as a current-carrying conductor. These circuits violate the provisions of the National Electrical Code and the UL/ANSI Standards. I have a low-cost personal computer and feel that my 120 VAC/12 VDC portable television set was a good in- vestment. BYTE should encourage the use of line-isoJated television sets and monitors and discourage the use of makeshift substitutes. ■ Steven A Schafer, 202 West Dr, Princeton N] 08540 The purpose of the ground wire in the standard power delivery system is to provide a stable reference and to bleed away any small charges caused by leakage currents or static. It should never be used to supply power to any device. A current of more than a few milliamperes in the ground line is enough to trigger a ground-fault inter- rupter, if such a device is installed. For the same reason, the neutral wire should never be connected to the ground wire; even though they are sup- posedly at the same potential, the neutral wire is not guaranteed to be at earth-ground, and connecting it to the ground wire will often cause a small current to flow. For obvious safety reasons, neither the hot nor the neutral side of the power line should be connected to any exposed conductor. The circuit shown in figure 1 is a nearly foolproof way to protect against wiring errors. If a polarity error exists between the protected equipment and any other devices connected to it, relay 2 and the neon indicator will turn on, disabling relay 1 and preventing power from being applied to the protected equipment. If there is no error, relay 2 remains off, and depressing the push-button switch -^ ' FAULT" RELAY #2 J, H A Q PROTECTED EQUIPMENT N ^ O t RELAY #1 t OTHER DEVICES Figure 1: Steven Schafer's power -line protection circuit. The Une marked H is the hot side of the power Une; the Une marked N is the neutral side of the power line. The resistor in series with the neon lamp should have a value of 100 k ohms. 96 September 1980 © BYTE Publications Inc Circle 63 on inquiry card. Circle 64 on inquiry card. HVCiRRULICS TUTOR VIDEO DATA PROCESSOR Called the VDP, comes complete with 1 6K memory, its own color text and graphics generator and is designed to superimpose its graphics and text over incoming video signals from video tape, video disk, TV camera, Apple Video or Broadcast • Color text and graphics on an independent screen • Video titling or video interactive training uses. It's like your own TV station, works with OUR Light Pen too! Available directly from Symtec at $1500.00. SPECIAL PROBLEMS We can help. Symtec does custom engineering, fabrication, hardware and software design for microprocessor. Beginning at $1500, these services can solve your custom application needs for industrial, scientific, medical, engineering or personal uses. SUPER SOUND GENERATOR Apple Music Power with a plus • 3 voices, 6 in stereo version • Noise generator • Independent control of volume, envelope and shape by channel • Full power, easy to use software to compose, edit, play in hi-res graphics, PLUS, input and output ports allow extra uses: • Printer interface • Remote ASCII or music keyboard interface • and, optional BSR X-10 Adapter is available. Suggested retail $159.95 mono, $259;95 stereo. SYMTEC X-10 CONTROL Now for the Apple II, a low cost control to link your computer to the BSR X-10 Home Control System. Control your home or office lighting and appliances • Energy management • Display lighting Security and more. Suggested retail $49.95. LIGHT PEN A professional quality, full feature light pen for the Apple II Computer • Hi-resolution — draw on the screen • X, Y and sensitivity adjustments — fits any standard TV • Sync adjustment for remote video source • Touch switch sets interface flag • Rugged metal case • Recommended by Apple. Complete, ready to go, the Symtec Light Pen is provided with software and documentation in Basic, Applesoft and machine code. Muse's Pilot II Language using the Symtec Light Pen is also available. The Light Pen is useable for graphics, games, education, exhibits, freedom from the keyboard. Suggested retail $249.95. I See your Apple DeaJer for a demonstration of the Sym- tec Ught Pen, Supersound Generator or Symtec Apple X-tO Control. Other products and services are availabte directly from Symtec. Apple is a trade mark of Apple Computer Inc. BSR System X- 1 is a trade marlt of BSR Ltd. Muse .Is the trade marit of Micro Users Software Exchange, Inc. 22223 Telegraph Rd.; Southfield, Mich. 48034 P.O. Box 462, Farmington, Mich. 48024 313-352-1790 More Printing Temrinals Froili MICROMftIL . . . PIABLO 1650 • Prints at 40 cps, using 88, 92, or 96 char, metalized printwiieels. • Vertical resolution 1/48"; Horizontal 1/120". Capable of proportional spacing, bidirectional printing, and graphics under software control. • Bidirectional normal and direct tabs. Left, right, top and bottom margins. R.O. $2890.00 KSR $3285.00 DIABLO Uses plastic printwheel and prints at 45 cps. Otherwise, shares identical features with 1650 including: — Friction or tractor feed, up to 1 5" wide. — Cartridge ribbon, fabric or carbon. LA 34 {Shown with optional fomns tractor and numeric keypad). • Prints 10. 12, 13.2, or 16.5 characters per inch, upper/lower case. • 2, 3, 4, 6, 8, or 12 lines per inch. • Friction feed, paper width to 1 5 $969.00 Options: — Numeric keypad — $80.00 — Adjustable forms tractor — $130.00 r^SiiS!:'"'' R.O. $2745.00 KSR $3140.00 • Includes upper/lower case option. • Bidirectional printing at 1 50 cps. • Tractor-feed forms, 3" to 1 5" wide. $1599.00 Options: — Forms length control —$100.00 — Vertical Format Control with Compressed Print — $1 25.00 ANADEX DP-9500/9501 • High Density Graphics • Parallel, RS-232C, and Current Loop interfaces standard. • Double width printing • 1 32/1 75 or 1 32/220 columns. 50 to 200+ n., 150/200 ■ tor 120/200 [ 9 font. 9-wire print head, 650 million character life. Bi-Directional printing with shortest distance sensing logic. Adjustable width tractor paper feed. Complete forms control. Call for Low Price We Also Represent the Following Manufacturers: TELETYPE GTC l^leVideo TEC SOROC Write or Call In for Our Free Cataloguel eiUJCHDirifUJ..! MtCROMAtL • BOX 3297 • SANTA ANA, CA 92703 (714) 731-4338 " TO ORDER: Send check or money order to: MICROIVIAIL, P.O. Box 3297, Santa Ana, CA 92703. Personal or company checks require two weeks to clear. Terminals in stock are shipped the business day after receipt of certified funds. All equipment includes factory warranty. I SHIPPING: We ship freight collect by UPS when possible. Larger terminals are shipped by motor freight. Air and express delivery is available on all products. HANDLING: All orders are subject to MICROMAIUs handling charges. Less than $750.00, add 3%. $750.00 to $2,000.00, add 2%. Over $2,000.00 add 1 %. will latch relay 1 on and apply power to the load. The only way to defeat the circuit is to hold the push-button switch closed while inserting the power plug in the wall socket. ■ Making 6502 Indirect Subroutine Calls Efficient Philip K Hooper, 5 Elm St, Northfield VT 05663 I enjoyed the article "Indirect Addressing for the 6502," by Kenneth Skier (January 1980 BYTE, page 118), and I would like to suggest some alternative techniques. These are based on the observation that once the subroutine of interest has finished executing, control may return direct- ly to the original calling program rather than to the in- terim location holding the volatile address of the subroutine. Implementing this permits savings in both time and storage, as will be shown. Approach A involves initially writing hexadecimal 4C (the JMP op code) into the first of three read/write memory locations, the second and third of which will be set dynamically to the actual address of the desired subroutine, as in Mr Skier's article. The subroutine will then be summoned correctly by a simple JSR to the read/write memory location containing the 4C. Return will be to the main program. Approach B requires no initialization of read /write memory, although two consecutive bytes of read/write memory must be reserved for use as a pointer. The main program does require three additional bytes containing hexadecimal 6C (op code for JMP indirect) followed by the address, low byte first, of the read/write memory location reserved for the pointer. In use, the pointer will be loaded (as before) with the actual subroutine address, and a JSR to the byte containing the 6C will result in the correct location, execution, and return from the desired subroutine. Table 1. Time overhiead in ^s Approacti used in article 24 (JSR JSR RTS RTS) Approach A 15 (JSR JMP RTS) Approach! B 17 (JSR JMPI RTS) Bytes needed to do initialization 8 or 10 4 or 5 Additional bytes of progrann nnennory 3 Bytes of read/write memory required 4 3 2 Bytes required by stack 4 2 2 Table 1 summarizes the storage and time overhead re- quirements of these three JSR(I) techniques. For sheer speed, approach A performs best, while approach B can save two or three bytes, at a cost of two cycles per in- vocation. ■ Circle 65 on inquiry card. Vz MByte TM-lOO-3 (Single-sided) Capacity (unformatted): 500K bytes TPIi 96 or 100 Tracks per side: 80 maximum Recording density: 5535 BPI Access time: • Track to track: 3 ms • Average: 90 ms GO FIRST CLASS At an economy Price It doesn't cost anymore to go first class when ifs a Tandon 5'^" flexible disk drive. The reason is simple. We're the recognized leader in mini-floppy read/write head technology. In fact, our patented, double-sided head design is used by all the other major mini-floppy suppliers. And, it makes no difference if you buy one or one-thousand drives, you'll always get the first class price/performance that's made Tandon first choice among OEMs of word processing, small business sys- tems, and personal computers. Tandon is rapidly becoming the first name in mini-floppies because we offer up to one megabyte of storage capacity, the fastest access time, a choice of single or double-sided recording, and 96 or 100 tracks per inch. All with proven reliability at an unbeatable price. Because we are the leaders in head technology, Tandon mini-floppies are designed beginning with the head to assure dependability throughout each drive. With Tandon, going first class is both sensible and economical. 1 MByte TM-lOO-4 (Double-sided) Capacity (unformatted): l.OOOK bytes TPI: 96 or 100 Tracks per side: 160 maximum Recording density: 5877 BPI Access time: •Track to track: 3 ms • Average: 90 ms landon 9333 Oso Ave. Chatsworth, California 91311 (213) 993-6644 Heads Above The Rest in Disk Technology Circle 304 on inquiry card. BYTE September 1980 99 Michael Fallgatter, 514 Bethesda Ct, Waukesha WI 53186 The article "Indirect Addressing for the 6502," by Kenneth Skier (referenced above), was most interesting, but I would like to point out that, in the case of indirect transfers to subroutines, a much faster-running linkage is possible. Rather than using the linkage routine: JSR RTS variable address Listing 2; Transfer from main program LDX subroutine j^-pointer to address in table STX zero-page byte §2 JSR zero-page byte ^1 Listing 3; Zero-page linkage routine to create subroutine call STX zero-page byte §2 JMP indirect, via subroutine address table the linkage using the 6502 indirect-jump command JMP variable pointer produces the same result, takes less memory, and cuts the time required for the transfer of control by over 50%, from thirty-eight to eighteen machine cycles. Using this technique and assuming a table of subroutine addresses residing in a single page of memory, the listings in Mr Skier's article become those shown here. Listing 4; Simulate indirect subroutine jump LDX subroutine § JSR CALL SUBROUTINE(X) Finally, since no indexed instructions are involved, the A register could be used instead of X. Also, there is a very minimal memory and execution-time penalty paid for using a nonzero page for the transfer routine. ■ Listing 1; Initiate zero-page bytes LDA mc ST A zero-page byte ^1 LDA ^Stable page STA zero-page byte §3 Write JMP indirect via pointer to subroutine address table 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 correspondents supply their full names and addresses to be printed with their commentaries. We also ask that cor- respondents supply their telephone numbers, which will not be printed. PRINTERS & CRT'S From Grange micro 9 bay^e^ inc. IMPACT PRINTER 649. 00 (LIST $699.00) 'The BASE 2 outperforms every printer in its price range. Do a comparison and see for yourself. . .'* • GRAPHICS • TRACTORS /FRICTION FEED • 2K Input Buffer • RS-232 Serial, Centronics® Parallel, IEEE-488, 20 ma • TRS-80 Cable option • 60 LPM - 100 CPS • Fast form feed • User programmable character set • 64, 72, 80, 96, 120, 132 Columns/ line • Expanded characters • 9.5" wide paper • Automatic skip-over- perforation • Horizontal & Vertical tabs • Programmable vertical line spacing • Intel 8085 Microprocessor — over 40 software commands • Self test • 15 Baud rates to 9600 Baud • Optional foreign character sets Interfaces to TRS-80, Apple, Atari, PET, Northstar, and most other computers. Circle 66 on inquiry card. TELEVIDEO CRT'S PRICES SLASHED! JVI912C TVI 920C } Please Call Toll Free Prices are too low to advertise PRINTERS OKIDATA CENTRONICS 779w/tractors $Call 730 $Call 737 849 COMPRINT 912 Parallel 499 912 Serial 535 MicrolineSO 639 w/tractors 739 PAPER TIGER w/graphics 948 QUME Letter Quality 5/45 2499 w/tractors 2684 TOLL FREE (800) 854-8275 CALIF. (714)630-3322 Call for FREE CATALOG ,0 ^gt Phone orders WELCOME. Same day shipment for VISA, MASTER CHARGE, and AMERICAN EX- PRESS. Personal checks require 2 weeks to clear. Add 3% for ship- ping and handling. California resi- dents add 6%. Manufacturer's warranty included. Prices subject to revision. Orange micro 3148E. La Palma, Suite E Anaheim, CA 92806 GOT A PIOGRAM FMYOy! The new computers are showing off. Over $50 nnillion worth of equipnnent in over 100,000 square feet of space, including the latest software and hard- ware for business, governnnent, honne and personal use. Every- thing the NCC show has and more will be on display, and you can buy it all right on the spot. Computers costing $150 to $250,000, mini and micro com- puters, data- and word-processing equipment, telecommunica- \ tions, office machines, peripheral equipment and services from 1^ leading names in the industry like IBM, Xerox, Radio Shack ■" ■- -^ and Apple will all be there. There'll be conferences on business uses of small to medium sized computers, and how to make purchasing 4 evaluations. ^^ There'll be robots, computerized video games, ^KL ^ computer art and computer music. 1^ i i Everyone from kids to people who earn their liv- ing with computers will have a great time at the larg- est computer show ever organized in each region. Admission for adults is $5. The public is invited, and no pre-registration is necessary. EJS: Don't miss the computer show that fslsb^T f^'x^s business with pleasure. Show lZ:E::f-!» up for the show. 1 m WASHINGTON, D.C, D.C. ARMORY/STARPLEX THURSDAY-SUNDAY SEPTEMBER 18-21 11 A.M. TO 9 P.M. THURS.-SAT. 11 A.M. TO 5 P.M. SUN. ■^^■^JiJJWJJg ^ji ™ j CHICAGO McCORMICK PLACE THURSDAY-SUNDAY OCTOBER 16-19 11 A.M. TO 9 PM. THURS.-SAI 11 A.M. TO 5 PM, SUN. Produced by National Computer Shows, \ 824 Boylston Street, Chestnut Hill, MA 02167. | Telephone (61 7) 739-2000. | Please send me: BOSTON HYNES AUDITORIUM PRUDENTIAL CENTER THURSDAY-SUNDAY NOVEMBER 20-23 11 A.M. TO 9 PM. THURS.-SAT. 11 A.M. TO 5 PM. SUN. - adult tickets at $5 each. I have enclosed the proper amount of $ D Information on the show's conference program. D Hotel registration information D Exhibitor rentalinformation P!easeprtnt:Name_ City„ , State. „2ip_ 'i ^i^-' BYTE September 1980 101 Machine Problem Solving, Part 1: Trial-and-Error Search, A Mechanical Plan to Save the Missionaries Professor Peter W Frey Northwestern University Cresap Neuroscience Laboratory 2021 Sheridan Rd Evanston IL 60201 Modern computers are famous for their number- crunching ability. Their facility at inverting a 60 by 60 matrix or at solving a set of linear differential equations is truly impressive. In fact, machines are so good at solving numerical problems that most of us take these skills for granted. Computers are also useful as general-purpose control devices. Many personal-computing enthusiasts enjoy im- pressing their neighbors with their machine's ability to control lights, water sprinklers, and burglar alarms, and to take telephone calls and regulate the furnace. Homes of the future will be completely computerized. The computer also makes an excellent bookkeeper: faithfully recording financial transactions, maintaining mailing lists, and generating timely reminders for impor- tant meetings. Personal computers also provide many hours of entertainment for their owners with games of manual dexterity, games of chance, and simulated battles among the stars or in dark dungeons. These many uses provide a clear rationale for the rapidly developing popularity of the personal computer. The most exciting application of the computer lies in still another direction. It is as a thinking machine that the modern computer truly sparks our imagination. When faced with a problem that has no easy numerical solu- tion, men have typically discarded their mechanical calculators and put on their proverbial thinking caps. For this type of problem, the human brain has always been superior to mechanical devices. An immense amount of respect for the human brain can be gained by trying to program a computer to select the best move in a game like chess. Even a multimillion-dollar mainframe com- puter turns out to be a woodpusher when asked to com- pete against a skilled human player. Solutions by Searching When machines confront nonnumerical problems, their primary weapon in finding a solution is to examine a vast labyrinth of potential outcomes in search of one which satisfies the desired conditions. Although this ap- proach is not very elegant, it is, in fact, highly similar to that used by humans. The noted psychologist Donald Campbell (see reference 1) observed that trial-and-error search plays a key role in human problem solving: "a blind-variation-and-selective-survival process is fun- damental to all inductive achievements, to all genuine in- creases in knowledge, to all increases in fit of system to environment." It is as a thinking machine that the modern computer truly sparks our imagination. Campbell also concluded that specialized problem- solving skills such as those observed in an experienced surgeon or airline pilot are "inductive achievements achieved originally by a blind-variation-and-selective- survival process." Thus, trial-and-error search provides the cornerstone for human efforts in acquiring new knowledge. Search is even more important in solving problems by computer. With most problems, humans have back- ground information which can be successfully employed to direct the solution process. Machines generally lack this. Problem solving by computer usually requires that all relevant facts be discovered during the solution pro- cess. This important difference between human and machine problem solvers has been addressed by recent efforts in artificial intelligence. By developing specialized information libraries, the computer scientist has created search programs which are reasonably competent at tasks such as diagnosing medical problems or developing three- dimensional models for complex chemical structures. For 102 September 1980 © BYTE Publications Inc Circle 67 on inquiry card. ' !V|T;sr>tv?t._j\^^j:^)j^*?|,^^ The MODEL 800 AAST is certainly pleasing to features reveals why it is rapidly becoming • Four standard interfaces: RS-232 (15 baud rates) Centronics compatible parallel IEEE-488 20ma current loop • Six line densities: 64, 72, 80, 96, 120, 1 • 100 CPS at all six densities • Unidirectional or bidirectional printing • Sixteen horizontal and ten vertical tabs • Elongated characters in all s'\% densities • 1920 character buffer • Uses either perforated or roll paper • Fully adjustable tractors to 9^2" • Auto self-test but maybe its most attractive fea look at, but its true beauty lies beneath the surface, A glimpse at its the most sought after printer in the world ... • Up to 10 character fonts Standard 96 character ASCII User defined character font Provision for up to eight additional, fonts • Dot resolution graphics in six densities 32 • Variable line spacing control from to 64 dots in half-dot increments • Auto form-feed for any form length at any line spacing • Heavy-duty .all aluminum chassis • 1 lOvac or 220vac, 50/60Hz. • 100 million character printhead • Measures only 15" wide, 3" high, and 1 1" deep • Weighs only 15 lbs. ture is the price $699.00. baxe^ inc. ^ P.O. BOX 354B FULL.,CAI.. 98634 / C714) 992-4344 most problem-solving efforts, however, it is much easier to emphasize search rather than sophisticated pattern matching. Games as Problems Games and puzzles provide excellent sample problems. Marvin Minsky states that "it is not that the games and mathematical problems are chosen because they are clear and simple; rather it is that they give us, for the simplest initial structures, the greatest complexity, so that one can engage some really formidable situations after a relative- ly minimal diversion into programming." (See reference 2.) Man's fascination with intellectual games is not a new phenomenon. The Dutch scholar Huizinga suggested many years ago that the human race should have been named homo ludens (the game player) rather than homo sapiens. There are two important aspects of playing a game or solving a puzzle. The first consists of representing the problem in a way that permits efficient analysis. The se- cond involves devising a search technique which is capable of finding a solution. The first task, finding a good way to represent the problem, is usually the key to an elegant solution. Unfortunately, few guidelines exist that provide a mechanical rule for developing a good representation. For this reason, problem representation generally must be devised individually for each game or puzzle by the human programmer. The situation is quite different in respect to the search process. In this case, there are well-developed principles that have proven useful in many different problem areas. My purpose in this article will be to focus on the search The most basic type of search is called the trial-and-error search. NORTHSTAR DISCOUNTS Quad Drive lor Horizon (orig mir) $ 550 Dbi. Dens. 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MAIL ORDERS: Box 4146, Arlington, Va. 22204 PHONE ORDERS AND INFORMATION: (703) 243-3770 RETAIL STORE: 4786 Lee Higfiway, Arlington, Va. 22207 VISA and MASTERCARD accepted. (Please give card number and exp. date) process and to consider general techniques that have broad applicability. Trial-and-Error Search The most basic type of search process is called trial- and-error search. In this case, the problem solver ex- amines various operations until a sequence is found that leads to a solution. In primitive implementations, the dif- ferent options are considered haphazardly rather than be- ing ordered according to a specific plan. To demonstrate this approach, we will develop a solution for the missionaries-and-cannibals problem. In its traditional form, this problem involves three mis- sionaries and three cannibals who are located on one bank of a river and wish to cross. A boat is available which will hold two people and which can be navigated by one or two people. The special restriction that makes the problem interesting is that the sequence of river cross- ings must never result in an arrangement where the can- nibals outnumber the missionaries on either bank. If the missionaries are outnumbered, their life expectancy will be immediately and permanently shortened. In determining the number of individuals on each bank, the persons in the boat when it reaches shore are considered to be residents of that bank. The object for the problem solver is to develop a schedule of river crossings which transports the entire party across without losing any missionaries. Representing the Problem The first step in addressing this problem is to find a representation that is compatible with a machine problem-solving approach. For our effort, we would like to write a program in Level II BASIC for the Radio Shack TRS-80 computer. This machine is widely available and has more than enough power to solve this puzzle. We will consider the problem in terms of discrete states and discrete operations. We will not concern ourselves with the details of paddling a boat across a river, but rather with the executive decisions, ie: who is to be in the boat on each journey across. The state space will consist of a description of the number and types of occupants on each bank before the boat makes a crossing or after a crossing is completed. We will employ a shorthand notation which represents a missionary by the letter M, a cannibal by the letter C, the boat by the symbol < = > , and the river by two vertical lines. Therefore, the character sequence CCMM I < = > I CM indicates that there are two can- nibals and two missionaries on the left bank of the river and one cannibal, one missionary, and the boat on the right bank. This notation is adequate to describe all possible states of the problem. The operations (ie: legal moves) we can perform to transpose one state into another are quite limited in num- ber. In fact, there are a maximum of five operations that can be used, and often only a subset of these will be fea- sible. The five operations consist of transporting (1) one 104 Seplember 1980 © BYTE Publications Inc Circle 68 on inquiry card. Announcing Texas Instruments Author Incentive Program... win up to $3,000. SQC fflt *W* fTf> tflt ^f» ^n *^j 2IO' S |^ DECISIONS ^^^ dt ^^f ^f^ ^^j- ^Bl^ ^^^ ^^V ivBft I^^V © 19f7S TEXRS X»STRyfl£NTS S^T^TI"ST1:CS lees- ^•ov r liiili :ilil PHeaff T FOR PRESS BKUO FOR SECTtai« [ ©1980 TEXftS INSTRUMENTS i % Musrc nnKER — ^^-pz — nEFlME IHVESTneNT LORNS LEASE'S; DEPRECIRTIOM CVnt-URTE INVEST MCprr an re or rctumm RESroeMXiniL RNftt-VSI^S Lonn •'it.e SAVE FEL.E © 1979 TEXRS INSTRUMENTS [vauR CHOICE? t n 1 ^ 1 WOT « PtOUK PU1CE ■ ■"""" 1 ■ wMra j , _ „ i -" " VIDEO CHESS UHITE I a 7 nnnnnnnn fi S 4 3 ? A A ;^- ^ ^ ^ ^ ;^ 1 ft^mir^k^^^\M ENTER nOS^ Texas Instruments is looking for unique home computer programs. 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Programs that are self -teaching, that communicate on hu- man terms. After all, the TI Home Com- puter was designed to be the first home computer the whole family can use. TI is interested in education, personal finance and technical or managerial pro- grams for professionals. Home manage- ment programs, hobby and simulation programs. We prefer that your submis- sions exclude entertainment packages. Your entry can be a program you've created for use on the TI-99/4 or other microcomputers — in any high-level lan- guage, from Pascal and BASIC to FOR- TRAN or COBOL — or even assembly language. All the way up to 48K RAM. Keep in mind that programs for the TI Home Computer can incorporate high- quality color graphics, music and sound effects, and TFs remarkably-human syn- thesized speech. Tb submit an entry, call the toll-free number below or use the reader ser- vice card in this magazine. We'll send you an entry submission form plus full details. Please don't send anything until you receive and fill out this entry form. Programs must be in by November 15, 1980 — so get your entry form soon. For an entry form, call 1-800-858-4565. Call between 8 a,m,-U:30 p,m. CDT, Mon-Fri, In Texas call 1-800-692-^279, © 1 980 Texas Instruments Incorporated Offer void where prohibited by law. Author Incentive Program not open to TI employees, TI consultants and contractors or their families. Texas Instruments INCORPORATED Circle 69 on inquiry card. 221085 •f %-^li^«i cannibal, (2) two cannibals, (3) one missionary, (4) two missionaries, or (5) one cannibal and one missionary. To execute one of these operations in a particular direc- tion, the boat must be located on the departure bank. In addition, an operator cannot be applied if the ap- propriate individuals are not present on the departure bank. For example, we cannot move two missionaries from the left bank to the right bank if there are fewer than two missionaries on the left bank at that point in time. Programming the Problem Our program will start with a few "housekeeping" functions that are necessary even though they have little to do with the logic of our solution. It is necessary to set aside 300 bytes of memory for string variables, to inform the machine that all variables that are not specifically defined as string variables are to be treated as integer variables (this saves memory and speeds execution), to define two special variables (X$ and Y$) for clearing sec- tions of the video display, and to blank out the entire screen. In addition, for our graphic presentations we need a representation for the boat on the left side of the river (BL$) and one for the boat on the right side of the river (BR$). All of this is accomplished in our first two lines (given here and as part of listing 1; the function STRINGS {n, "X") returns a string consisting of n symbols using the first character of "X" ): 100 CLEAR 300: DEFINT A-Z: Y$ = STRING$(40,""): CIS 110X$ = STRING$(9,""): BL$ = "< = > "+X$:BR$=X$ + "< =>" It is also helpful to set up a few arrays to store essential information. We need to know the position of the boat, the number of cannibals on the left bank, and the number of missionaries on the left bank after each river crossing. This information will be retained in arrays B, C, and M. We also need to remember which of the crossing options (1 cannibal, 2 cannibals, 1 missionary, etc) we have con- sidered at each choice point in our crossing sequence. This information is stored numerically by array D and for graphic purposes in string array MV$. Finally, we need to specify the crossing options with respect to the cannibals, array CT, and the missionaries, array MT. The TRS-80 is instructed to establish these arrays in line 120: 120 DIM B(30), C(30), CT(5), D(30), M(30), MT(5), MV$(30) To make the program more interesting, we will generalize the problem so that the number of travelers can vary from four to sixteen. The number of travelers will be represented by the variable N which can be specified by the user: 130 PRINT@526, "NUMBER OF TRAVELERS (4 TO 16)";: INPUT N 140 CLS: IF N<4 OR N>16 THEN 130 Line 140 makes sure that the value entered for N is in the proper range. This is important with the TRS-80 because keyboard bounce is apt to provide a value like 122 when we intended 12. The program would experience difficul- ties if it attempted execution with N set at a value of 122. Next, we set the stage properly. First we need a title (line 150) and then we need a river for our travelers to cross (line 160): 150 PRINT@24, "MISSIONARIES AND CANNIBALS"; 160 FOR K = 4 TO 43: SET (58,K): SET (85,K): NEXTK Program Operation Now it is time to get on with the main act. The initial number of cannibals on the left bank (CI) is computed as Listing 1: Trial-and-error solution to the cannibals-and- missionaries problem, written for the TR5-80 in Level II BASIC. 100 CLEAR 300: DEFINT A-Z: Y$ = STRING$(40;^ "): CLS 1 1 X$ = STRINGSO," "): BL$ ="<=>" + X$:BR$ = X$ + "<= > " 120 DIM B(30), C(30), CT(5), D(30), M(30), MT(5), MV$(30) 130 PRINT@526, ^^NUMBER OF TRAVELERS (4 TO 16)";: INPUT N 140 CLS: IF N<4 OR N> 16 THEN 130 150 PRINT@24, "MISSIONARIES AND CANNIBALS"; 160 FOR K = 4 TO 43: SET(58,K): SET(85,K): NEXT K 200CI = INT(N/2):MI = N-CI: BP=1: 1 = 210 CL = CI: CR = 0: ML = MI: MR = 220 CT( 1 ) = 2 : CT(2) = 1 : CT(3) = : CT(4) = : CT(5) = 1 230MT(1) = 0: MT(2) = 0: MT(3) = 2: MT(4) = 1: MT(5)=1 300 GOSUB 2000: GOSUB 1000 310C(I)=CL: M(I) = ML: B(I) = BP 320 IF ML = AND CL=0 THEN 700 330 FOR K = 1 TO 800: NEXT K 3401 = 1 + 1: D(I) = 350 D(I) = D(I)+1: IF D(I)>5 THEN 600 360IFBP=-1 THEN 380 370 IF CL0 AND CL>ML THEN 500 420 IF MR > AND CR > MR THEN 500 ELSE K = 430 IF CL = C(K) AND ML = M(K) AND BP = B(K) THEN 500 440K = K + 1: IF K " ELSE MV$(I) = "<-" + A$ + B$ 470 GOTO 300 500 BP= -BP: CL = CL + BP*CT(D(I)): CR = CI-CL 510 ML = ML + BP*MT(D(I)): MR = MI -ML: GOTO 350 600 PRINT@960, "BACK UP AND TRY SOMETHING ELSE"; 610 1 = 1- 1: IF I< 1 THEN PRINT® 960, Y$;: GOTO 800 620CL = C(I-1): CR = CI-CL: ML = M(I- 1): MR = MI-ML 630BP = B(I-1): GOSUB 2000: GOSUB 1000 640 FOR K = 1 TO 800: NEXT K 650 PRINT® 960, Y$;: GOTO 350 700 PRINT® 960, "SUCCESS";: GOTO 700 800 PRINT® 64, X$;: PRINT® 960, "FAILURE";: GOTO 800 1000 IF 1 = THEN RETURN 1010 FOR K = l TO 14: PRINT® K*64, X$;: NEXT K 1020S = I-13:IF S< 1 THEN S=l 1030 FOR K = S TO I: J-K-S+1 2000Z$ = STRING$(8-CR," "): CR$ = STRING$(CR,"C") + Z$ 2010Z$ = STRING$(8-CL," "): CL$ = Z$ + STRING$(CL,"C") 2020Z$ = STRING$(8-MR," "): MR$ = STRING$(MR,"M") + Z$ 2030Z$ = STRING$(8-ML," "): ML$ = Z$ + STRING$(ML,"M") 2040 IF BP = 1 THEN B$ = BL$ ELSE B$ = BR$ 2050 PRINT® 468, CL$;: PRINT® 492, CR$;: PRINT® 478, B$; 2060 PRINT® 532, ML$;: PRINT® 556, MR$;: RETURN 106 September 1980 © BYTE Publications Inc The MAG?C wsfuyid . ALMOST PERFEC. We've been saying it for a few months now, and the reviewers seem to agree. 4 i Until 1 saw the Magic Wand, if 1 were allowed to own one and only one editor, Word Star* would have been it. . . . My personal preference is for Pencil or Magic Wand for text creation. 5 5 Jerry Pournelle On Computing, Summer 1980 4 4 The basic functions of the Magic Wand editor are as easy to learn as those of Electric Pencil*. . . . Magic Wand dominates in the area of print formatting. 5 ? Larry Press On Computing, Summer 1980 4 4 Of all the word processors 1 have used (and that includes a dozen or more), the Magic Wand is the most versatile. The Wand has almost all of the features of other processors, plus many new ones of its own. It measures up to even the word-processing software running on the largest mainframe computers.? ?Rod Hallen Microcomputing, June 1980 4 4 The Magic Wand is one of the most flexible word processing packages available, and should be considered by any potential word processing purchaser. ? ? Glenn A. Hart Creative Computing, August 1980 Available for both the CP/M® and OASIS operating systems 3220 Louisiana • Suite 205 • Houston, Texas 77006 • 713-528-5158 Circle 70 on inquiry card. Electric Pencil is a trademark of Michael Shrayer Soltware, Inc. WordStar is a trademark of Micro Pro International, Inc. CP/M is a registered trademark of Digital Research Corp. BYTE September 1980 107 is the initial number of missionaries on the left bank (MI). We will assume an equal number of missionaries and can- nibals when N is even and an extra missionary when N is odd. (If there were an extra cannibal at the beginning, our problem would end before we had a chance to try our first crossing.) The position of the boat will be indicated by the variable BP. When the boat is on the left bank, BP will have a value of 1. A value of —1 will indicate that the boat is on the right bank. The index reflecting the number of crossings (I) is set to zero and the values for the variables indicating the number of cannibals on the left bank (CL), the number of cannibals on the right bank (CR), the number of missionaries on the left bank (ML), and the number of missionaries on the right bank (MR) are also initialized: 200 CI = INT(N/2): MI = N-CI: BP = 1: 1 = 210 CL = CI: CR = 0: ML = MI: MR = We also wish to specify each crossing option by specify- ing the number of cannibals (CT) and the number of mis- sionaries (MT) who are transported: 220 CT(1) = 2: CT(2) = 1: CT(3) = 0: CT(4) = 0: CT(5) = 1 230 MT(1) = 0: MT(2) = 0: MT(3) = 2: MT(4) = 1: MT(5) = 1 The main loop of our program begins with calls to two subroutines which handle the graphic display. One subroutine (which appears later in this article at line FULL COLOR GRAPHICS The original 256-color imaging system with high resolution video FRAME GRABBER for the S-100 bus. .,.^'% Capture and digitize a video fr^mein l/60of a second. Select the best resolution foryour . application, from 256 to 1280 pixels ^^^s^^ per TV line. 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The other subroutine (line 2000) provides a pic- torial representation of the current position of the mis- sionaries, cannibals, and boat. These routines are not essential for solving the problem, but they add a nice touch to the program and allow the user to watch the machine's "thought processes." These subroutines are in- voked at line 300: 300 GOSUB 2000: GOSUB 1000 Each time through the loop, it is necessary to make a permanent record of the current status of our principal characters: 310 C(I) = CL: M(I) = ML: B(I) = BP and then to check to see if the problem has been solved: 320 IF ML = AND CL = THEN 700 If not, we create a brief delay so that the human observer will not miss any of the action: 330 FOR K = l TO 800: NEXT K and then get about our main business, examining the feasibility of making a particular crossing by increment- ing I by one and initializing D(I), which keeps track of the particular crossing option we are trying at each step I in the crossing sequence. The variable D(I) is then in- cremented and a test is made to see if we have exhausted the available options: 340 1 = 1 + 1: D(I) = 350 D(I) = D(I) + 1: IF D(I)>5 THEN 600 Testing Options If all options have been tried without success, the machine is directed to line 600 and asked to execute a back-up procedure that tries another option at an earlier position in the sequence. If we still have a viable option at this previous value of I, we continue by examining the particular crossing option which is indicated. First, we determine the location of the boat (line 360), then make sure we have a sufficient number of missionaries and can- nibals on the departure bank to carry out the indicated crossing (lines 370 and 380), and finally we make the crossing (lines 390 and 400): 360 IF BP=-1 THEN 380 370 IF CL AND CL> ML THEN 500 420 IF MR> AND CR> MR THEN 500 ELSE K = 108 September 1980 © BYTE Publications Inc Circle 71 on inquiry card ^sja. ^x ^ »y ■.Ft BASIC SOFTWARE LIBRARY NOW ^ 10 ^ Volumes and Growing IS SPONSORING A $10,000.00 Give Away WHY Pay hundreds of dollars for Software that does Not work when WE offer the BEST available Software for only a few dollars a program. And what is better OURS WORKS! We have over100,000 in circulation since 1975 and we are still around and That's more than Anyone else can say. 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A/R A/P Merlnv Check Assets Payroll BalSh P/L Year End Data Base Tax Up Basic St. Volume VI — Disk programs are compatible with TRS-80 disk basic The disk programs in Volumes VI, VII and X are written in (CP/M) M Basic and Disk Extended Microsoft Basic. Other programs written in 8K Basic. Unconditional Money Back Guarantee. Add $1.50 per volume handling, all domestic shipments sent U.P.S. except APO and P.O. Box which go parcel post. Foreign orders add $6.00/volume for air shipment and makepayablein U.S. dollars only. AVAILABLE AT MOST COMPUTER STORES Master Charge and Bank Americard accepted. Our Software is copyrighted and may not be reproduced or sold. Unlike others we have NOT raised our prices in five years FIRST DRAWING — September 11, 1980 and every week thereafter until December 18, 1980. Winners will be notified within one week. For a list of winners send a self-addressed stamped envelope with a request for the winners list. No PURCHASE Necessary, to enter send name & address on 3 3x5 card. You are automatically entered every time you make a purchase from us. Void where prohibited by LAW. KEMCO, LTD. P.O. Drawer 2208L Petersburg, VA 23803 circle 72 on inquiry card. IN GERMANY Ing. W. Hofacker, GmbH Holzkirchen, W. Germany IN HOLLAND Nanton Press B.V. Bilthoven, Holland OVER 116,000 IN USE TOPAyJ The Ultimate Software Package from Hgh Technclcgy, Incl" IT'S THE ULTIMATE PACKAGE... Designed for flawless performance and re- volutionary user-ease INFORMATION MAS- TER'' performs all the following functions us- ing the APPLE lr^ INFORMATION MASTER'", the soft- ware package that will organize your customer lists, inventories, ex- pense records, student information files, accounts receivable and pay- able . . . AND IF THAT'S NOT ENOUGH, it will print your mailing labels, pro- duct catalogs, budget analysis, physical inventory checksheets ... it's so adaptable that the appli- cations are virtually limitless. ^ioiSB ^■^B ORGANIZING SORTING SEARCHING SELECTING ALPHABETIZING SCHEDULING INDEXING CALCULATIONS MULTIPLICATION DIVISION ADDITION SUBTRACTION EXPONENTIATION SUMMATION REPORTING PAGING LABELING CATALOGING SUMMARIZING TOTALING SUBTOTALING But the final word is DOCUMENTATION. We at High Technology know that even a brilliantly conceived program is useless if you can t under- stand it. That's why user-ease is the distinction between what is merely a good package and a truly excellent one. INFORMA- TION MASTER'" user's manual contains over 100 pages of illustrations, examples and ex- planations of the program, be- ginning with a step-by-step trial run. Your computer dealer has o demonstration pack- age. Drop by and see what THE ULTIMATE PACKAGE can do for you. ^^ High Technology, Inc. P.O. Box 14665 Oklahoma City, Oklahoma 73113 (405) 840-9900 "APPLE \s a registered trademark of APPLE COMPUTER. INC. / In addition to an insufficient number of the ap- propriate persons or the threat of cannibalism, there is another reason for discarding the current crossing plan and going to line 350 to try another. This third reason has to do with repetition of a previous state of the system. We have no desire to create loops which transport the same individuals back and forth forever. In lines 430 and 440, we check to make sure that the current state has not occurred previously: 430 IF CL = C(K) AND ML = M(K) AND BP = B(K) THEN 500 440 K = K + 1: IF K " ELSE MV$(I) = "< -" + A$ + B$ 470 GOTO 300 Backing Up This completes the main loop of the program. We have a few loose ends which need to be taken care of before the job can be considered finished. When we found that a crossing option was not feasible either because of can- nibalism (lines 410 and 420), or because of repetition of a previous position (lines 430 and 440), the machine was in- structed to go to line 500 and reverse its previous move. Line 500 must therefore exist as follows: 500 BP= -BP: CL = CL + BP*CT(D(I)): CR = CI-CL 510 ML = ML + BP*MT(D(I)): MR = MI-ML: GOTO 350 After returning to line 350 to try another crossing, we may find that all five options have been exhausted. If so, it is time to back up our search and try something dif- ferent at an earlier point in the crossing sequence. The back-up instructions start at line 600: 600 PRINT@960, "BACK UP AND TRY SOMETHING ELSE"; 610 1 = 1-1: IF Kl THEN PRINT® 960, Y$;: GOTO 800 620 CL=C(I-1): CR = CI-CL: ML = M(I-1): MR = MI-ML 630 BP=B(I-1): GOSUB 2000: GOSUB 1000 640 FOR K = l TO 800: NEXT K 650 PRINT® 960, Y$;: GOTO 350 The back-up procedure is a little tricky. First, we decre- ment I by 1, then we set the current status of our main characters to the way it was before we made the last crossing. Our objective is to examine another crossing option at the new value of L To do this, the position we transform must be the situation as it existed before the 110 Seplember 1980 © BYTE Publications Inc Circle 73 on inquiry card. Circle 74 on inquiry card. WHEN OPPORTUNITY KNOCKS ... f i^' r Open the door, and experience the dream. Your own busi- ness, the one youVe always yearned for. No more iimits on your creativity or earning potential. No more working for someone else. If you're a successful computer professional and have access to some capital, chances are you could own a MicroAge Computer Store. MicroAge Computer Stores are built around a whole new concept of what a computer store should be. Designed to provide solutions, not just sell hard- ware. MicroAge Computer Stores are firmly positioned in the bus- iness and professional marketplace. And as a MicroAge Computer Store owner, you'll be backed by one of the acknowledged leaders, industry pioneers in microcomput- ing. Contact the Director of Franchising today to receive a complete Franchise Information Package free of charge and at no obligation. Opportunity is knocking . . . you'll see what we mean. cQ44PUTer store 1425 W. lah Place • Tempe. AZ 85281 • (602) 967-1421 A search program such as this one can be quite effective if the number of possible move combinations is not too large. last move. The back-up procedure also calls our graphic routines (line 630), delays a bit for dramatic effect (line 640), and then erases the back-up message (line 650) before exiting for line 350. There are two terminal conditions for the search pro- cess. If we move all the cannibals and missionaries across the river, our mission is successfully completed. This con- dition is detected by line 320 which directs the machine to line 700: 700 PRINT® 960, "SUCCESS";: GOTO 700 If we back up to the point where 1 = 0, then we have ex- hausted all possibilities and our search has failed. This state of affairs is tested in line 610 and if it holds, the machine is sent to line 800: 800 PRINT® 64, X$;: PRINT® 960, "FAILURE";: GOTO 800 This finishes our program except for specifying the two subroutines which maintain our video display. The first of these occurs at line 1000 and keeps an up-to-date listing of the crossing sequence: 1000 IF 1 = THEN RETURN 1010 FOR K = l TO 14: PRINT® K*64, X$;: NEXTK 1020 S = I-13: IF S<1 THEN S = l 1030 FOR K = S TO I: J = K-S + 1 1040 PRINT® J*64, K; " "; MV$(K);: NEXTK: RETURN The second subroutine provides a graphic display of the current position of the boat and of all missionaries and cannibals: 2000 Z$ = STRING$(8-CR," "): CR$= STRING$(CR,"C") + Z$ 2010 Z$ = STRING$(8-CL," "): CL$ = Z$ + STRING$(CL, "C") 2020 Z$ = STRING$(8-MR," "): MRS = STRING$(MR, "M") + Z$ 2030 Z$ = STRING$(8-ML," "): ML$ = Z$+STRING$(ML,"M") 2040 IF BP = 1 THEN B$ = BL$ ELSE B$=BR$ 2050 PRINT® 468, CL$;: PRINT® 492, CR$;: PRINT® 478, B$; 2060 PRINT® 532, ML$;: PRINT® 556, MR$;: RETURN Limitations and Features A search program such as this one can be quite effec- tive if the number of possible move combinations is not too large. The missionaries-and-cannibals problem is an ideal example for this type of search because there is a limited number of options at each choice point. If there were many options at each choice point, a simple trial- and-error search might take a very long time to find a solution sequence. If there were a solution, however, it would find it. The key features of this program are the I index and the D(I) array. If we use game terminology, the I variable in- dexes the move number (ie: first move, second move, third move, etc) and the D(I) array keeps track of which move option is currently being considered at each level I of the search. In the missionaries-and-cannibals problem, our program exhaustively considers the various move op- tions. It accepts the first legal move option it can find at each level I of the search. A move is legal unless it fails one of the three tests (in- sufficient passengers, lines 370 and 380; cannibalism, lines 410 and 420; or repetition, lines 430 and 440). The search continues forward until it reaches a level where none of the five possible move options are feasible. It then backs up until it can find a new move option at a lower level and then starts forward again. This is a simple yet powerful strategy. Improving the Process Our implementation of this strategy could be made considerably more "intelligent" if we gave some thought to the order in which crossings are considered. In lines 220 and 230, we define the five crossing options. We could reduce the number of back-ups by establishing one order of move consideration for trips across to the right bank and another order for trips back to the left bank. The interested reader might enjoy looking at academic studies which have examined this issue in detail (see, for example, reference 3). Some minor modifications can in- crease the efficiency of the present program by a large factor. One strategy for implementing this idea consists of defining one set of crossing options for left-to-right movement (say lines 220 and 225) and another set of crossing options for right-to-left movement (say lines 230 and 235) and then selecting between the two depending on the value of BP. Many problems require more direction to the search process if a solution is to be found in a reasonable amount of time. Next month, in the second part of this three-part article, we will consider a much more challeng- ing endeavor, cryptarithmetic. Allen Newell, one of the pioneers in analyzing human thinking in terms of information-processing models, made extensive use of cryptarithmetic as a valuable research paradigm. We will develop a search program in TRS-80 Level II BASIC that is capable of solving all cryptarithmetic problems. ■ References 1. Campbell D T, "Blind Variation and Selective Survival as a General Strategy in Knowledge-processes," Self-Organizing Systems, edited by Yovits and Cameron, Pergamon Press, New York, 1960, pages 205 thru 231. 2. Minsky, M (editor), Semantic Information Processing, MIT Press, Cambridge MA, 1968, page 12. 3. Jeffries R, P G Poison, L Razran, and M E Atwood, "A Pro- cess Model for Missionaries-Cannibals and Other River- crossing Problems," Cognitive Psychology, 1977, volume 9, pages 412 thru 440. 112 Seplember 1980 © BYTE Publications Inc Circle 75 on inquiry card. ^^ito***^^ The computer that grows as you grow. . ^^yr^ ^^^ *^<^^. *^^^^ /^ ■C:A ^^^JT V *iN lib IS ail WnwmA /\s your computer skills grow, so does your Heath H-8 System. New accessories and software are coming along all the time to make your system do more. Special bus design gives you seven plug-in board posi- tions soyou can configure any combination of memory; I/O's and accessories. You can interchange boards. Add accessories. Build exactly the system you want. A wide selection of software makes your life more fun and more efficient. Hundreds of programs forbusinesS; home and family are available from Heath User's Group. Also two BASIC languages; Microsoft^" and Fortran!" And more programs are being developed all the time. If you haven't seen the latest Heathkit catalog, you haven't seen the latest in computer fun. There's a new Music Synthesizer Board, new Speech Lab, new Color Visit jrour Heathkit Store /n the U.S. and Canada visit your ^ nearby Heathkit Electronic Cen- ter* where Heathkit products are displayed, sold and serviced. See the white pages of your phone book for the location nearest you. "Units ofVeritechnology Electronics Corporation in the U.S. CP-188 Graphics Board and new Color Monitor. And coming soon, a new three-drive disk system. For an exciting computer hobby, there's no more exciting computer than the Heath H-8 — available fully assembled or in money-saving kit. For complete details and prices on the H 8 and the com- plete line of Heath printers, terminals and accessories, write today for the new,/ree Heathkit Catalog, or pick one up at your nearby Heathkit Electronics Center. Heatif Send for FREE CATALOG Write to Heath Com- pany, Dept. 334-694, Benton Harbor, MI 49022 Complete support, so you're never left out in the cold. evTE'^ eits A Better Way to Indirectly Address the 6502 In the article "Indirect Addressing for the 6502," by Ken Skier in the January 1980 BYTE (page 118), there was an error in listings 2 and 3. Because absolute ad- dresses occupy 2 bytes, the address of the Xth subroutine will be in posi- tion 2X in the address table, not the Xth. This problem can be corrected by storing the high address bytes in one table and the low-order bytes in another. With this structure the Xth entry will correspond to the Xth Listing 1 CALL.X LDA TBL.HI,X PHA LDA TBL.LO,X PHA RTS subroutine. I would like to suggest two other methods of im- plementing indexed indirect jumps which are more effi- cient in terms of code length and execution time. The first method is that of vec- toring: 3 bytes are reserved as the "vector." The first byte always contains a hexa- decimal 4C (JMP). The target address is placed in the next 2 bytes and a JMP or JSR is then done to the vector, so that control passes to the selected module. The second method, however, is the more effec- tive and concinnate. Sup- ;GET ADDRESS X, HIGH BYTE ;AND PUSH IT TO THE STACK ;GET ADDRESS X, LOW BYTE ;AND PUSH IT TO THE STACK ;GO TO ROUTINE X pose that we wish to call routine X, and that the ad- dress table is structured as 2 rows: TBL.LO and TBL.Hl. Consider the routine CALL.X, shown here as listing 1. By doing a JMP or JSR to CALL.X an indexed indirect JMP or JSR will be effected to the Xth routine. One point to be observed here is that the execution of a RTS instruction pops the stack into the program counter, and then increments it. Thus the addresses in the table must be one less than their actual value. Thomas Gettys, Co-editor SYM-Phi/sis SYM-1 Users' Group FOB 315 Chico CA 95927 Notes on Attending a USUS Meeting The first meeting of the USUS (UCSD System Users Society) was held in San Diego, California, on June 20 and 21, 1980. The meeting was called by SofTech Microsystems, then turned over to the approx- imately one hundred par- ticipants at the meeting. Speakers at the meeting in- cluded Carl Helmers and Ken Bowles. Organization, choosing a name, and the election of officers were the main formal goals. Jim Bandy was elected president, A Winsor Brown was elected vice-president. Chip Chapin was elected secretary, and Jon Bondy was elected treasurer. Infor- mal accomplishments includ- ed the usual exchange of in- formation which occurs be- tween users of similar soft- ware. The next meeting of the USUS group will coin- cide with the Minicomputer and Microcomputer Con- ference and Exposition to be held on October 14, 15, and 16, 1980, in San Francisco, California. For further infor- mation, contact the secretary. Chip Chapin, at the following temporary ad- dress: UCSD System Users Society, attn: Chip Chapin, Secretary, 9494 Black Moun- tain Rd, San Diego CA 92126.... CHB n#- POWER MODEM T-M. • RS 232 Connnnunications over existing AC power lines. • Easy installation - plug into AC ^ receptacle. • 110 or 300 BAUD rate - switch selectable. • Full duplex operation. • Multipoint network capability. • Standard DB 25 I/O connector. Order one per each communication point • $139.00 each including shipping • C.O.D., check or money order. BAY TECHNICAL ASSOCIATES, inc. Highway 603 • Bay St. Louis, MS. 39520 P.O. Box 387 (601] 467-8231 114 September 1980 © BYTE Publications Inc Circle 76 on inquiry card. BASF FlexyDisk 1 m than four decades of experi- ence in magnetic media -BAvSF 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. Special self -cleaning jacket and liner help eliminate data errors and media wear and tear BASF BASFFIexyDisIc Center hole diameter punched to more accurate standards than industry specifications, for top performance. Bi-axially oriented polyester substrate -for uniform and reli- able performance year after year. Cross-linked oxide coating- for low head wear and long trouble- free media life. 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. See us at the NCC, Booth 1121 BASF Floppy Disks Mag Cards Cassettes Computer Tapes Disk Packs Computer Peripherals Circle 77 on inquiry card. APL Character Generator John W Langner 411 Monterey Blvd Apt B Hermosa Beach CA 90254 Photo 1: Video screen display of the character set produced by the APL character-generator circuit described in this article. Photo 2: The circuit of figure 1 as constructed on a small per- forated circuit board. Many computer enthusiasts are beginning to use APL and are discovering the benefits of this powerful high-level language. Unfortunately, most personal com- puters are not equipped to generate the special APL characters. Various solutions to this problem have been proposed, ranging from using inverse-video characters to using a Author's Note: Readers who wish to build this circuit but do not have access to an erasable programmable read-only memory (EPROM) programmer can obtain preprogrammed 2708s from the author for $20. programmable display that allows you to define any characters you want under program control. Here is another solution. With the addition of only a few integrated circuits, and with only a single change in your present video interface, you can have the essential APL characters, including overstrikes. The circuit presented here should work with any video display using the popular MCM6571 character generator and can easily be adapted for others. The first thirty-two positions in the MCM6571 are oc- cupied by Greek letters and other seldom-used characters. The idea is to replace these with APL characters. After I listed the useful APL characters and 116 September 1980 © BYTE Publications Inc For those special peopewnave stepped ahead withmminhcompuler 1 * « f r f » f Maxell offers a way to stay ahead. A Maxell SW Mini-Disk will consistently let you maxi- mize the capability of your system today And as your involvement with it grows, tomorrow as well. Maxell Mini-Disks are all made with the same exacting 100% certification and critical dependability of the Maxell 8" Floppy Disk. So you know your 5Va'' Maxell Mini-Disks meet or exceed the same ISO and Shugart specifica- tions industry requires. There are double density Maxell single and double- sided SVa' Mini-Disks for soft and hard sector systems. And 8" Maxell Floppy Disks for every disk drive config- uration. See your computer supply dealer or write to us for more information, If you are a computer products dealer, write for the growing opportunities Maxell Business Products Division offers you with our 8" Floppy and 5Va" Mini-Disks. maxell. BUSINESS PRODUCTS DIVISION Maxell Corporation of Annerica, Business Products Division, 60 Oxford Drive, Moonachie, NJ. 07074 Tel: 201-440-8020 Circle 78 on inquiry card. , i,j %« :^ ii- TO VIDEO DISPLAY <±\ O- 2~T0'1 SELECTOR »C5 74157 38 28 18 STR08E SELECT TO VIDEO DISPLAY \ij> -[i8> 15 ~;h 4A 3A IC6 74157 2A 4Y lA 48 38 3Y 2Y 28 lY 18 STR08E SELECT 2'TO-I SELECTOR 12 15 HT9> ■{I> -{20> "^ 0= SELECT 6571 1=SELECT 2708 IC4 74145 BCD-TO-DECIMAL Number Type + 5V GND -3V +12V -5V IC1 6571 2 13 1 3 IC2 2708 24 12 19 21 IC3 74150 24 12 1C4 74145 16 8 IC5 74157 16 8 IC6 74157 16 8 Figure 1: Schematic diagram of the character-generator circuit which is to be constructed on a small circuit board for connection to the main video display board by a multiconductor cable. All connections are made through a 24-pin dual-in-line plug that plugs into the socket vacated by the removal of the MCM6571 from the video display board. The MCM6571 socket must have —5 V potential applied to its pin 14; this is the only modification needed on the video display board itself. Adding this —5 V connection does not affect normal operation since pin 14 on the MCM6571 package is not connected inside. To get the { and } characters instead of the 7^ and >^ characters, disconnect pin 16 of the 74150 device. eliminated those already found in the ASCII (American Standard Code for Information Interchange) character set, thirty-five remained to be implemented. Most people can probably do without the braces and accent grave (( ) ') from the ASCII character set, so I replaced them. If you need to have the braces, you can substitute them for the A (NAND) and V (NOR) sym- bols. The circuit to produce the APL characters is presented in figure 1. It contains the original MCM6571 character generator from the video interface and a 2708 erasable programmable read-only memory (EPROM) pro- grammed as an APL character generator. The 74145 BCD-to-decimal decoder and 74150 l-of-16 data selector decide which character generator to select, and the 74157 noninverting 2-to-l-line data selectors act accordingly. The circuit can be built on a small board and plugged into your video display with a short ribbon cable and a 24-pin dual-in-line plug. The only modification to your video interface is to connect —5 V to pin 14 of the character-generator socket. This will not affect normal operation because pin 14 is not connected inside the MCM6571. The data that must be programmed into the 2708 is listed in table 1. The character codes that invoke the APL characters are shown in table 2. ■ 118 September 1980 © BYTE Publications Inc Circle 79 on inquiry card. It Most small system users think all microcomputers are created equal. And they're right. If you want performance, con- venience, styling, high technology and relia bility (and who doesn't?) your micro usually has a price tag that looks more like a mini, seems big performance always means big bucks. But not so with the SuperBrain. Standard SuperBrain features include: twin double-density 5y4" drives which boast over 300,000 bytes of disk storage. A full 32K of dynamic RAM - easily expandable to 64K. A CP/M* Disk Operating System which insures 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 modu- lar design to make servicing a snap. A com- mon 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 $3,000. it is truly one of the most re- markable microcomputers available anywhere. Whether your application is small business, scientific or educational, the SuperBrain is certainly one of today's most exciting solutions to your microcomputer problems. Call or write us now for full details on how you can get big system performance without having to spend big bucks. So, why not see your local dealer and try one out today. Intertec systems are distributed world- wide and may be available in your area now. INTERTEC DATA SYSTEMS. 2300 Broad River Rd, Columbia. SC 29210 (803) 798-9100 TWX- 810-666-2115 'Registered ttademarli olOigitai Research. Inc ^. -«i|. Puces rellccl disirtoition on B single density ctiskclles II a loimal is Sotlware / requested wdich requires additional drskeHes, a surcliargc ol S8 per wUh / Manual addihoiial diikeite will be added A suicha!geolS2S will Beatlded toi Manual/ Alone soltwaro onCSSN lomal DC 300XL carlndge'j Mcdm cJiargi; (or 5440 disiK IS $100 /^ D FORTRAN-80-ANSI 66 (except for COM- /^y ® PLEX) plus many extensions. Includes relocat- / ^ ;■■-, @ able object compiler, linking loader, library with ^^ C" ■ '-■ manager. Also includes MACRO-80 (see ^^^^^ , '^\-,*:., below) S425/S25 |i|^^ •I^Jb ^^^BPNw'^ "■■' /^ ] COBOL-80- Level 1 ANSI "74 standard ■\|fl in .^^^H ^^. r ® COBOL plus most of Level 2. Full sequential, ' ^^^ ■ ■ ^^ ■ ^^BM^^k..::^^H^V ® ''elative, and indexed file support with variable ^^^^ ■ ■ ■ ^r^^^B^^^m file names. STRING. UNSTRING, COMPUTE, m ■ ^^^^ ^^^ 1^^^ m^^z:::zz^ '^^^^v varying/until, extend, call, copy, ■ ^^^■^P^^^^k ^^^k H^^K^ m^Fa^'~^^ ^^^^V SEARCH, 3-dimensional arrays, compound H ^^p|H H^^ ^^^^^ ^^0M V H^k^ H HL^^H^ ^^^^v andabbreviatedconditions, nested IF. Powerful B^^^^B^^^^]^^^^" ^T^B ^L^ .^P vV B ^ ^ ^^^y interactive screen-handling extensions. In- l^^^^l ^^^^^ ^■l^li B^^^ ^m ^BI^B^^B eludes compatible assembler, linking loader. ^B and relocatable library manager as described ^ under MACRO-80 S700/S25 {nO.^^.c^oOP/M'^/lnj^O 7L D MACRO-80- 8080/Z80 Macro Assembler. i^i^a^-c4faz Ur/^ Wx^ /iZ^JiCe M- s„„^^^^ ^ ,ntei and Zilog mnemonics supported, Relocat- ^^, J /^^ A ffi. ^j ^ . / Manual / Aiono^' ® ^ble linkable output. Loader, Library Manager /f4hu£^M^yyUUc)f and Cross Reference List utilities AM Lifeboat programs require CP/M, D SMAL/80 Structured Macro Assembler included S149/S15 unless otherwise stated. ® Language- Package of powerful general ,-, muSIMP/muMATH-muSIMP iq a hiah level So/f^ar.^ for . ,os/ OOp./a. mSOiZm PtS?ed^ranauTae"co'mS"sMAL is an^'as' © progrTm^n ''ar^glgrslirable' for'^fmSfc computef dish systems ILr^i^iZ ^^n^^^^^ f^.^and semi-numerical processing. Implemented so«... / mOpfREPE^T WHI^E DO-'eND BEG^N-' Nosing a fast and effic'ient inter'preter requuing ^:^^ I rr 'ENgconftmcfs . . Syl/Sis' - ^ ^^'V ^'< ^^^^ °^ machine code. muMATH is a package of programs written in muSIMP The D CP/M- FLOPPY DISK OPERATING SYS- „„^^„.^ o^^^»..»^ .oo ^^^ — package performs sophisticated mathematical TEM-Digital Research's operating system PHOENIX SOFTWARE ASSOCIATES functions. Keeps track of up to 611 digits. Per- configured for many popular micro-computers □ paSM*-Z80 macro assembler, lnte!/TDL forms matrix operations on arrays: transpose, and disk systems: ® mnemonics. Generates Intel hex format or re- multiply divide, inverse and other integer pow- . _, . [ ..^locatable code in either TDL Object Module ers. Logarithmic, exponential, trigonometric / \ System^ Version Hnce v(]|^ormat or PSA Relocatable Binary Module for- simplification and transformation, symbolic dif- f^^j/J Apple H* -■:■■_- 2.x 350/25 |\J/ „! at. Supports text insertion, conditional ferentiation with partial derivatives, symbolic in- ^ SoftCard with Z80 -.^ branching within macros, recursive macro calls tegration of definite and indefinite integrals. Microsoft BASIC version 5 and parameter passing S129/S25 Requires 40K CP/M S250/S20 with high resolution ^ 1. ^^ _, ,, _■■ i graphics □ EDIT- Character oriented text file editor. In- g muLISP-79- Microcomputer implementation North Star Single Density . . . 1.4 . . . .145/25 ® / ® eludes macro definition capabilities. Handles ® of LISP The interpreter resides in only 7K bytes North Star Double Density . . 1.4 . . . .145/25 , fl(A).^'"ser^'on. deletion, searching, block move,, etc. of memory yet includes 83 LISP functions. Has North Star Single Density ..2.x. ..170/25 /\Jti^for files of any length. Does not require a kWmjjnfinJte precision integer arithmetic expressed North Star Double/Quad ... 2.x ... .1 70/25 ' ^ CRT S1 29/$25 \^ y \n any radix from 2 to 36. muLISP-79 includes Durango F-85 2.x 170/25 □ PLINK*— Two pass disk-to-disk linkage edi- complete trace facility and a library of useful iCOM Micro-Disk 2411 1,4 145/25 ® tor/loader which can produce re-entrant, functions and entertaining sample iCOM 3712 1 .4 . . . .170/25® ' i n ROMable code. Can link programs that are programs S200/S15 Eif^^^S/^Ait^^ir ppnn 11 • ■ ■ M^m * Mt>Mflarger than available memory for execution □ XMACRO-86-8086 cross assembler. All Hoth mrI M 7 4 • • ■ ■ d^/?^ <8. V ^^^9^!?^ °^ another mach me. Full library © Macro and utility features of MACRO-80 pack- m! f h MflQ 1 ■ • ■ M^ill ^ ^^P^?f !f ^ ^"f^l ??k"- ^^ k'^^? Relocatable Bi- age. Mnemonics slightly modified from Intel HeathH89 1.4. .. .145/25® nary Module, TDL Object Module or Microsott ASM86 Comoatibilitv data sheet Heath H89 b y Magnolia . . . . 1 .4 . . . .250/25 O reL files. Output carl be a COM file, Intel hex avaHable ^ ° "" P ^ ^ ' ^ ' " ^ V ^ ^ ^ S275/S25 Heath H89 by Magnolia .... 2.x .. . .300/25 O fjie. TDL Object Module or PSA Relocatable _ I^IZ ' w' ' ' V '. 5^^b/5^b Onyx C8001 2.x 300/25 O fj|e $129/S25 □ EDIT-80— Very fast random access text editor Ohio Scientific 03 2.x 200/25 ^ „, ,'_, " ' .' ' '^'.r^i, ' '^on ■ V ,• i,- ® for text with or without line numbers. Global and TRS-80Modell ... ,14 145/25® □ BUG and ^ BUG -ZbO interactive machine intra-line commands supported. File compare TRS-80 Model II 2x 170/25 ® '^^^' debugging tools for program develop- utility included S89/S15 TRS-80 Model II h- Corvus' ! 2;x ! . ! ,250/25 i, (n li) ["^"*- ^^^ \l?^ ""' symbolic trace and interac- Processor Technology N^?,?cMfr^'^ (mnemonics compatible with Helios II '.' 1 .4 . , .145/25 I ^^ .^^.^Jt^hiPeSna SZlah RoS) ub5g □ PASCAL/M*- Compiles enhanced Standard Cromemco System 3 1 .4 . . , .145/25 ^ c^S^^'ubip; o' BUG and is 3s^^^^^ ® Pascal to compressed efficient Pcode. Totally Intel MDS Single Density . . 1.4 . . , .145/25 LLh cifnltinncr \^oo^^ol CP/M compatible. Random access files. Both Intel MDS Single Density , . . 2.x . . . .170/25 ""^''^° situations 5129/S25 ^g ^^^ ^^^^.^ Integers. Runtime error recovery. Micropolis Mod I 1,4 ., . .145/25 ® Convenient STRINGS. OTHERWISE clause on Micropolis Mod II 1 .4 145/25 ® DIGITAL RESEARCH CASE. Comprehensive manual (90 pp. inde- The following configurations are scheduled for □ MP/M— Installed for single density MDS-800, '^ed). SEGMENT provides overlay structure, release soon: Multi-processing derivative of the CP/M op- INPORT OUTPORT and untyped files for arbi- Norlh Star Double/Quad erating system. Manual includes CP/M2 trary I/O. Requires 56K CP/M. Specify 1)8080 + Coivus 2.x 250/25 documentation S300/S50 CP/M, 2) Z80 CP/M, or 3) Cromemco North Star Horizon HD-1 ,. 2.x .... 250/25 n ..*/. onon .. u, .r CDOS S175/S20 nhir. Q^ionfifi^ m n ov o«;n/o«; Q MAC-8080— Macro assembler. Full Intel ^ „.„^.. „ ^„„ . „.^^., S^r?r.Sfc: Mnri^l 2 / ' " ' 200/2^ ® ^acro definitions. Pseudo Ops include RPC, □ PASCAL/Z-Z80 native code PASCAL com- ^Tc»o^^ Mr>Y QTn IRP- REPT, TITLE, PAGE, and MACLIB. Pro- ® Pi'er. Produces optimized. ROMable re-entrant R. if Qwcfom 9 V -^cin/oci " duces absolute hex output plus symbol table file ® code. All interfacing to CP/M is through the iPOM ?R^? 5v ■ " ■ ioZii ' for use by SID and ZSID (see below) S120/S15 support library. The package includes compiler, lUUM jbi^ . , ^.x i.dXii/Xi r^ 1- .. _■ 1- ir 11 . relocating assembler and linker, and source iCOM 451 1/Pertec D3000 . . 2,x . . , . 375/25 -+ D SID-8080- Symbolic debugger. Ful trace, jq, all library modules. Variant records, strings So/fware cons/sfs of frte op^^ai\ng system, text ® E.!.?h?,u?,^^1,nH^Sn^r J'nS^ ^^^ direct I/O are supported. Requires 56K editor, assembler, debugger and other utilities ^Jl^lf. map nrn^wiS?,^ !l.hn S.nV..^^^^ CP/M- S395/S25 'S;^^^/rsTo7Sfc memoXel^-a'Xualedl^r^^^^ D PASCAL/MT- Subset of standard PASCAL. Complete set of Digital Research s documen- ^ ® Generates ROMable 8080 machine code. tation and additional implementation notes in- D ZSID-Z80— Symbolic debugger with all fea- ^ Symbolic debugger included Supports inter- cluded. Systems marked * and " include firm- ® lures of SID SI 30/S15 ^upt procedures, CP/M file I/O and assembly ware on 2709 and 27/6, S/sfemsmaf;cec/+ in- ® language interface. Real variables can be BCD, dude 5440 rnedia charge. Systems marked q jEX-Text output formatter to create paginat- software floating point, or AMD 9511 hardware ® require the special ® versions of soft- (^ ed, page-numbered and justified copy. Output floating point. Includes strings enumerations ware in this catalog Systems (parked ® have can be directed to printer or disk , . .S105/S15 and record data types. Manual explains BASIC minor variants available to suit console inter- _ tn PA^PAI rnnwprQinn RpnuirPQ ^9K '59«5n/ face of system. Call or write for full list of op- □ OESPOOL- Utility program to permit simulta- l°3o ^^^'- c°"^^^s.on. Requires 32K , .$250/ tions.O includes hardware addition to allow our ® neous printing from text files while executing ^ " ^ standard versions of software to run under it. o'^er programs SBD/SIO Q APL/VBO- Concise and powerful language for ■ —-•-■• — — — — — — — — — — — — — «— ©application software development. Complex r-i -»Qn rtcrwcri r>niicrki-r nA/^irA/-tr r> ■ D tiny C— Interactive interpretive system for ® programming problems are reduced to simple y ?/ P^ I r, r J P'*^'^ AGE — Consists (X) teaching structured programming techniques. . \ expressions in APL. Features include up to 27K ® of: (1 disk file line editor with global inter and Manual includes full source listings .S105/S50 k Onactive workspace, shared variables, arrays of ® L7e?X/Mostek r^'nlmonicf c'ondi?ona?a^: □ BDS C COMPILER- Supports most features N!l^up to 8 dimensions, disk workspace and copy ser^bV and cfostre^^^^^^^^^ ® o^ .language, including Structures, Arrays, ^/v 'iSor^fof Sac nq 1^^^^^^^ (3) linking loader producing absolute Intel hex ® P°'"*f ^ recursive function evaluation, over- Ses^SK CP/M and Le^^^^^^ disk file S95/S20 lays Includes inking loader, library manager, ^^ '^f ^Sx ^^^^ ^""^ ^^"^' ^^^ ^ S500/S30 and library containing general purpose, file I/O, nai or OH I SbUU/SJU D ZDT-Z80 Monitor Debugger to break and and floating point functions. Lacks initializers, n ALGOL-60- Powerful block-structured lan- ® examine registers with standard Zilog/ statics, floats and longs. Documentation in- ® guage compiler featuring economical run-time ® MosVek mnemonic disassembly displays. $35 dudes "The C PROGRAMMING LANGUAGE" dynamic allocation of memory Very compact when ordered with Z80 Development by Kernighan and Ritchie S145/S25 (24K total RAM) system implementing almost ^^^^^^^ ■ • S50/S10 ^ WHITESMITHS C COMPILER -The ultimate a" Algol 60 report features plus many powerful ® in systems software tools. Produces faster extensions including string handling direct disk AVOCET SYSTEMS ® code than a pseudo-code Pascal with more address I/O etc S199/S20 D XASM-68— Non-macro cross-assembler with extensive facilities. Conforms to the full UNIX* D CBASIC-2 Disk Extended BASIC— Non- nested conditionals and full range of pseudo Version 7C language, described by Kernighan ® interactive BASIC with pseudo-code compiler operations. Assembles from standard Motorola and Ritchie, and makes available over 75 tunc- and run-time interpreter. Supports full file con- MC6800 mnemonics to Intel hex . . .S200/S25 tions for performing I/O, string manipulation irol, chaining, integer and extended precision n YAQM R«; Ac YAQM KP w MOQ To^hn^i^nw ^nd Storage allocation. Linkable to Microsoft variables, etc $120/$15 Mrl^"cfnn"c:pL. m^ptn^ wnn/?i? REL files. Requires 60K CP/M S630/S30 MCb-6500 series mnemonics 5200/525 D XASM-48- As XASM-68 for Intel MCS-48 and uirpf^QnPT UPI-41 families S200/S25 MiuMuauf i MICRO FOCUS a XASM-18-As XASM-68 for RCA 1802 ° co'^'miafufl^w it'll ^on^a'^'l^a'liaMe'^amef ' ° STANDARD CIS COBOL- ANSI 74 COBOL S200/$25 I 5v°h7l'e'/WENd" hai'nini 'vlriLb?e'lenaT life ® S^r.fnlN^^.rll^litL^'nf.^^' '^^.^; ^I7n . ^ S3Z5/S25 teststo ANSI level 1. Supports many features to ° 8MJorTO?;?Xi,an1losScerde lfst'i°naand ° ^^^'C COMPILER- Language compa.lble ro5lfJ"atd'L"?ul?Is"^Sli,SSrii?o°p°- oTs°LSenS' lef lntiro?TDutii npsluSo ® ^I'^.^^SIC-eO and 3.^ , ,3^^^^^^^^^^^^^^^ ^^^^ ssgmsn.a.ior,, ir„erac.ive 'debug ar,d OPS optional. Runs on 8080 S?5/S10 ® ^™,^"o'^pu,=Sl)t M^CTOlsa'^fso^nl^aN^ S'anlf'Jn^Sd cirs?r'e°eXan°g D DISILOG-As DISTEL to Zilog/Mostek to FORTRAN-80 or COBOL-80 code from COBOL programs used with any dumb ® mnemonic files S65/S10 modules S350/S25 terminal S850/S50 ® Lifeboat Associates, 1651 Third Avenue, N.Y,, N,Y, 10028(212) 860-0300 Telex: 220501 Neu in der Schweiz Lifeboat Associates GmbH, Aegenstr 35, 6340 Baar Telefon 042/31 2931 with /Mi ilanual/ Al D FORMS 2 — CRT screen editor. Output is (D COBOL data descriptions for copying into CIS COBOL programs. Automatically creates a query and update program of indexed files using CRT protected and unprotected screen formats. No programming experience needed. Output program directly compiled by STAN- DARD CIS COBOL S200/S20 EIDOS SYSTEMS n KISS— Keyed Index Sequential Search. Offers (D complete Multi-Keyed Index Sequential and Di- rect Access file management. Includes built-in utility functions for 16 or 32 bit arithmetic, string/integer conversion and string compare. Delivered as a relocatable linkable module in Microsoft format for use with FORTRAN-80 or COBOL-80. etc S335/S23 n KBASIC- Microsoft Disk Extended BASIC ® version 4,51 integrated by implementation of nine'additional commands in language. Pack- age includes KISS. REL as described above, and a sample mail list program S585/S45 To licensed users of Microsoft BASlC-80 (MBASIC) S435/S45 n XYBASIC Interactive Process Control BASIC— Full disk BASIC features plus unique commands to handle byte rotate and shift and to test and set bits. Available in several ver- sions: Integer ROM squared S350/S25 Integer CP/M S350/S25 Extended ROM squared S450/S25 Extended CP/M S450/S25 Extended Disk CP/M S550/S25 Integer CP/M Run Time Compiler , ,S350/S25 Extended CP/M Run Time Compiler S450/S25 D RECLAIM— A utility to validate media under CP/M, Program tests a diskette or hard disk surface for errors, reserving the imperfections in invisible fites, and permitting continued usage of the remainder. Essential for any hard disk. Requires CP/M version 2 S80/S5 D BASIC UTILITY DISK- Consists of. (1) ® CRUNCH-14— Compacting utility to reduce the size and increase the speed of programs in Microsoft BASIC 4,51, BASiC-80 and TRS-SO BASIC. (2) DPFUN— Double precision subrou- tines for computing nineteen transcendental functions including square root, natural log, log base 10, sine, arc sine, hyperbolic sine, hyper- bolic arc sine, etc. Furnished in source on dis- kette and documentation S50/S35 D STRING/80— Character string handling plus routines for direct CP/M BDOS calls from FORTRAN and other compatible Microsoft lan- guages. The utility library contains routinesthat enable progr?:ns to chain to a COM file, retrieve command line parameters and search file direc- tories with full wild card facilities. Supplied as linkable modules in Microsoft format. $95/S20 D STRING/80 source code available separately- .S295/NA D THE STRING BIT- FORTRAN character ® string handling. Routines to find, fill, pack, move, separate, concatenate and compare character strings. This package completely eliminates the problems associated with character string handling in FORTRAN. Supplied with source S65/S15 D VSORT— Versatile sort/merge system for fixed ® length records with fixed or variable length fields. VSORT can be used as a stand-alone package or loaded and called as a subroutine from CBASIC-2. When used as a subroutine, VSORT maximizes the use of buffer space by saving the TPA on disk and restoring it on com- pletion of sorting. Records may be up to 255 bytes long with a maximum of 5 fields. Upper/ lower case translation and numeric fields supported S175/S20 □ CPM/374X— Has full range of functions to cre- ate or re-name an IBM 3741 volume, display directory information and edit the data set con- tents. Provides full file transfer facilities be- tween 3741 volume data sets and CP/M files S195/S10 s, \(h&-yi.^ CPAids D MASTER TAX— Professional tax preparation ® program. Prepares schedules A, B, C. D, E, F t G, R/RP, SE, TC. ES and forms 2106, 2119, 2210, 3468, 3903, 2441, 4625, 4726, 4797, 4972. 5695 and 6521. Printing can be on readily available, pre-printed continuous forms, on overlays, or on computer generated, IRS ap- proved forms. Maintains client history files and is interactive with CPAids GENERAL LEDGER II (see below) S995/S30 D STANDARD TAX— As above for schedules A, t B, C, D, E. G. R/RP. SE, TC and forms 2106 and 2441. Also, does not maintain client history files S495/S30 D GENERAL LEDGER II- Designed for CPAs. t Stores complete 12 month detailed history of transactions. Generates financial statements, depreciation, loan amortizations, journals, trial balances, statements of changes in financial position, and compilation letters. Includes payroll system with automatic posting to gen- eral ledger. Prints payroll register. W2s and payroll checks $450/530 with /Manua Manual/ Alone with /Manual Manual/ Atone n T/MAKER— Powerful new tool for preparing management reports with tabular data, fvlakes financial modeling projects easy. Do you want a ^ weekly profitability report? Set up the table and '\'^'/' compute. Just change the sales figures for next -^ week and compute. You have a new report! T/MAKER includes a full screen editor for setting up tables which pages left, right, up and down. Compute includes standard arith- metic, percents, exponents, common tran- scendental functions, averages, maxima, minima, projections, etc. Requires 48K CP/M and CBASIC-2 S275/S25 D BSTA M — Utility to link one computer to another ® also equipped with BSTAM. Allows file transfers at full data speed (no conversion to hex), with CRC block control check for very reliable error detection and automatic retry. We use it! It's great! Full wildcard expansion to send *. COM, etc. 9600 baud with wire. 300 baud with phone connection. Bothendsneedone. Standardand ® versions can talk to one another. .S150/S10 n WHATSIT?* — Interactive data-base system using associative tags toretrieveinformationby subject. Hashing and random access used for fast response. Requires CBASIC-2 .S175/S25 n SELECTOR lll-C2~Data Base Processor to t create and maintain multi-key data bases. ® Prints formatted sorted reports with numerical summaries or mailing labels. Comes with sam- ple applications, including Sales Activity, Inven- tory, Payables, Receivables, Check Register, and Client/Patient Appointments, etc. Requires CBASIC-2. Supplied in source S295/S20 D GLECTOR— General Ledger option to SELECTOR III-C2. Interactive system provides for customized COA. Unique chart of transac- tion types insure proper double entry book- keeping. Generates balance sheets, P&L statements and journals. Two year record al- lows for statement of changes in financial posi- tion report. Supplied in source. Requires SELECTOR III-C2. CBASIC-2 and 56K system S350/S25 D CBS— Configurable Business System is a comprehensive set of programs for defining custom data files and application systems with- out using a programming language such as BASIC, FORTRAN, etc. Multiple key fields for each data file are supported. Set-up program customizes system to user's CRT and printer. Provides fast and easy interactive data entry and retrieval with transaction processing. Report generatorprogram does complex calcu- lations with stored and derived data, record selection with multiple criteria, and custom for- mats. Sample inventory and mailing list sys- tems included. No support language required S295/S40 MICRO DATA BASE SYSTEMS D HDBS— Hierarchical Data Base System. CODASYL oriented with FILEs, SETs. REC- ORDS and ITEMS which are all user defined. ADD, DELETE. UPDATE, SEARCH, and TRAVERSE commands supported. SET order- ing is sorted, FIFO, LIFO, next or prior. One to many set relationship supported. Read/write protection at the FILE level. Supports FILEs which extend over multiple floppy or hard disk devices. n MDBS — Micro Data Base System. Full network database with all features of HDBS plus multi- level read/write protection for FILE, SET REC' D WORD-STAR— Menu driven visual word pro- ® cessing system for use with standard terminals. Text formatting performed on screen. Facilities for text paginate, page number, justify, center and underscore. User can print one document while simultaneously editing a second. Edit facilities include global search and replace, Read/Write to other text files, block move, etc. Requires CRT terminal with addressable cursor positioning S445/S40 D WORD-STAR-MAIL-MERGE-As above with ® option for production mailing of personalized documents with mail lists from DATASTAR or NAD S575/S40 n WORD-STAR Customization Notes- For sophisticated users who do not have one of the many standard terminal or printer configura- tions in the distribution version ol WORD- STAR SNA/$95 n WORD-MASTER Text Editor- In one mode ® has superset of CP/M's ED commands includ- ing global searching and replacing, forwards and backwards in file in video mode, provides full screen editor for users with serial address- able-cursor terminal S145/S25 D TEXT WRITER III- Text formatter to justify and ® paginate letters and other documents. Special features include insertion of text during execu- tion from other disk files or console, permitting recipe documents to be created from linked fragments on other files. Has facilities for sorted index, table of contents and footnote insertions. Ideal for contracts, manuals, etc. Now compati- ble with Electric Pencil* and Word-Star pre- pared files S125/S20 PEACHTREE SOFTWARE D General accounting software for small busi- ® nesses. Each product can be used alone or with t automatic posting to the general ledger. Supplied in source for Microsoft BASIC 4.51. GENERAL LEDGER S530/S40 ACCOUNTS PAYABLE S530/S40 ACCOUNTS RECEIVABLE S530/S40 PAYROLL S530/S40 INVENTORY $660/S40 ALSO: MAILING ADDRESS S530/S40 PROPERTY MANAGEMENT S925/S40 GRAHAM-DORIAN SOFTWARE SYSTEMS D Comprehensive accounting software written in ® CBASIC-2 and supplied in source code. Each ® software package can be used as a stand-alone t system or integrated with the General Ledger for automatic posting to ledger accounts. Re- quires CBASIC-2. GENERAL LEDGER S805/S40 ACCOUNTS PAYABLE S805/S40 ACCOUNTS RECEIVABLE S805/S40 INVENTORY SYSTEM S555/S40 JOB COSTING S805/S40 APARTMENT MANAGEMENT . . . .S805/S40 CASH REGISTER S805/S40 n POSTMASTER— A comprehensive package icvc. .cQu, .»...cLj.vy.ci.i.ij., .vy. . ..-._, vj.-,, ...-v./- ® 'o"" "^3il list maintenance that is completely ORDand ITEM. Explicit representation 'of one Kji>>i,;^«,' menu driven. Features include keyed record toone, one to many, many to many, and many to f;(i' 'extraction and label production. A form letter one SET relationships. Supports multiple program is included which provides neat letters owner and multiple record types within SETs. , s on single sheet or continuous forms. Includes ' ■■ - ■ ,\jJ' /:,NAD ffe translator. Requires CBASIC-2 J^!^ $150/520 HDBS files are fully compatible. D HDBS-Z80 version $250/S40' n MDBS-280 version S750/S40" 8080 version available at $75 extra. When ordering, specify one of the language interfaces listed below. Additional language in- terfaces available at time of purchase for $100 or S125 if purchased later. "The single manual covering HDBS and MDBS when purchased alone comes without specific language interface manual. Manuals are available for the following Microsoft lan- guages: 1) MBASIC 4.51, 2) BASIC-80 5.0, 3) Compiled BASIC or FORTRAN-80, 4) COBOL-80, 5) MACRO-80 SNA/S10 MICROPRO D SUPER-SORT I— Sort, merge, extract utility as ® absolute executable program or linkable mod- ule in Microsoft format. Sorts fixed or variable records with data in binary, BCD. Packed Deci- mal, EBCDIC. ASCII, floating & fixed point, ex- ponential, field justified, etc. Even variable number of fields per record! S225/S25 D SUPER-SORT II— Above available as abso- ® lute program only S175/S25 n SUPER-SORT lll-As II without SELECT/ ® EXCLUDE S125/S25 D DATASTAR— Professional forms control entry ® and display system for key-to-disk data cap- ture. Menu driven with built-in learning aids. Input field verification by length, mask, attribute (i.e. upper case, lowercase, numeric, auto-dup, etc.). Built-in arithmetic capabilities using keyed data, constant and derived values. Visual feed- back for ease of forms design. Files compatible with CP/M-MP/M supported languages. Re- quires 32K CP/M S350/S35 STRUCTURED SYSTEMS GROUP □ Complete interactive accounting software for t business. Each product can be used stand- alone or with automatic posting to the general ledger. Each product is thoroughly tested and very well documented. Each product requires CBASIC-2. GENERAL LEDGER S820/S40 ACCOUNTS RECEIVABLE S820/S40 ACCOUNTS PAYABLE .... S820/S40 PAYROLL S820/S40 INVENTORY CONTROL S820/S40 NEW! NEWSLETTER, FROM LIFEBOAT Latest Version Numbers List of Software Update on CP/M Users Group • The Great ZOSO Speaks Out from Behind the Scenes $18 ppd. for 12 issues (U.S., Canada, Mexico). Elsewhere $40. Send Check to "Lifelines," 1651 Third Avenue, New York, N.Y. 10028 or use your VISA or /Wasferc/iarge-call (212) 722-1700 Software I Manual/ Alone" [I] ANALYST— Customized data entry and report- t ing system. User specifies up to 75 data items per record. Interactive data entry, retrieval, and update facility makes information management easy. Sophisticated report generator provides customized reports using selected records with multiple level break- points for summarization. Requires a disk sort utility such as QSORT, SUPER-SORT or VSORT and CBASIC-2 S250/S15 n LETTERIGHT— Program to create, edit and type letters or other documents. Has facilities to enter, display, delete and move text, with good video screen presentation. Designed to inte- grate with NAD for form letter mailings. Re- quires CBASIC-2 S200/S25 D NAD Name and Address selection system- Interactive mail list creation and maintenance program with output as full reports with refer- ence data or restricted information for mail labels. Transfer system for extraction and trans- fer of selected records to create new files. Re- quires CBASIC-2 S100/S20 D QSORT— Fast sort/merge program for files with fixed record length, variable field length information. Up to five ascending or descend- ing keys. Full back-up of input files created S100/S20 ******* CONDIMENTS ******* D HEAD CLEANING DISKETTE- Cleans the drive Read/Write head in 30 seconds. Diskette absorbs loose oxide particles, fingerprints, and other foreign particles that might hinder the per- lamance of the drive head. Lasts at least 3 months with daily use. Specify 5" or 8" Single sided S20 each/S55 for 3 Double sided S25 each/S65 for 3 D FLIPPY DISK KIT- Template and instructions to modify single sided 5'/4" diskettes for use of second side in single sided drives S12.50 D FLOPPY SAVER— Protection forcenter holes for 5" and 8" floppy disks. Only 1 needed per diskette. Kit contains centering post, pressure tool and tough 7 mil mylar reinforcing rings for 25 diskettes. 5", Kit S14.95 5", Rings only $7.95 8", Kit $16.95 8", Rings only S8.95 □ PASCAL USER MANUAL AND REPORT- By Jensen and Wirth, The standardtextbookon the language. Recommended for use by Pascai/Z, Pascal/M and Pascal/MT users S12 D THE C PROGRAMMING LANGUAGE-By Kernighan and Ritchie. The standard textbook on the language. Recommended for use by BDS C, tiny C, and Whitesmiths C users . .$12 D STRUCTURED MICROPROCESSOR PRO- GRAMMING- By the authors of SMAL/80. Covers structured programming, the 8080/ 8085 instruction set and the SMAL/80 lan- guage .$20 D ACCOUNTS PAYABLE & ACCOUNTS RECEIVABLE-CBASIC-By Osborne/ McGraw-Hill $20 G GENERAL LEDGER- CBASIC- By Osborne/McGraw-Hill .$20 n PAYROLL WITH COST ACCOUNTING- CB ASIC- by Osborne/McGraw-Hill . . . $20 D LIFEBOAT DISK COPYING SERVICE- Transfer data or programs from one media for- mat to another at a moderate cost . .from $25 ******* Hearty Appetite. ******* •CP/M and MP/M are trademarks of Digital Re- search. Z80 i s a trademark of Zilog. Inc. UNIX is a trademark of Bell Laboratories. WHATSIT? is a trademark of Computer Head- ware. Electric Pencil is a trademark of Michael Shrayer Software. TRS-80 is a trademark of Tandy Corp. Pascal/M is a trademark of Sorcim. SoftCard is a trademark of Microsoft. Apple is a trademark of Apple Computer. PASM, PLINK, BUG and/xBUG are trademarks of Phoenix Software Associates Ltd, CPAids is a trademark of Computer Tax Ser- vice, Inc. t Recommended system configuration consists of 48K CP/M, 2 full size disk drives, 24 x 80 CRT and 132 column printer. • Modified version available forusewith CP/M as implemented on Heath and TRS-80 Model I computers. ® User license agreement for this product must be signed and returned to Lifeboat Associates before shipment may be made. ® This product Includes/eXcludes the language ® manual recommended in Condiments. © Serial number of CP/M system must be suppliedwith orders. ® Requires Z80 CPU. Copyright © 1980 Lifeboat Associates. No por- tion of this advertisement may be reproduced without prior permission. Ordering Information MEDIA FORMAT ORDERING CODES When ordering, please specify format code. Computer ayBtom Format Code LIFEBOAT ASSOCIATES MEDIA FORMATS LIST Diskette, cartridge disk and cartridge tape format codes to be specified when ordering software for listed computer or disk systems. All software products have specific requirements in terms of hardware or software support, such as MPU type, memory size, support operating system or language. Computer •yslem Format Code Altair 8800 Disk . . . .See MITS 3200 Alios Ar Apple + SoftCard 13 Sector RG Apple+ SoftCard 1 6 Sector RR BASF System 7100 RD Btacktiawk Single Density 03 Blacktiawk Micropolis Mod II . . 02 CDS Versatile 3B 01 CDS Versatile 4 02 COMPAL-80 02 Cromemco System 3 A V Cromemco Z2D R6 CSSN BACKUP (tape) Tl # Delta AT Digi-Log Microlerm II ,RD Digital Microsystems Al* Discus See Morrow Discus Durango F-65 RL Dynabyte DB8/2 R1 Dynabyte DB8/4 Al' Exidy Sorcerer ^ Lifeboat CP/M .02 Exidy Sorcerer t Exidy CP/M . . .04 Heath H8 + H17/H27 P4 Heath H69+ Lifeboat CP/M .. ,P4 Heath H89+ Magnolia CP/M , . .P7 Helios II .See Processor Technology Horizon See North Star iCOM 2411 Micro Floppy R3 iC0M3712 Al iCOM3812 Ar iCOM4511 5440 Canridge Cp/M 1.4 01 # iCOM 4511 5440 Cartridge CP/M 2.2 02* Prices F.O.B. New York. Shipping, handling and COD charges extra. Manual cost applicable against price of subsequent software purchase. The sale of each proprietary software package conveys a license for use on one system only IMS 5000 RA IMS 8000 AT IMSAI VDP-40 R4" IMSAIVDP-42 R4" IMSAIVDP-44 R5" IMSAIVDP-80 Al" Intecolor See ISC Intecolor Intel MDS Single Density Al Intenec SuperBrain DOS 0.1 . . .R7 Intertec SuperBrain DOS 0.5-2.X .RJ Intertec SuperBrain DOS 3.x RK ISC Intecolor 8063/8360/8963 . .Al Konlron PSl-80 RF MecaSVV P6 Micromalion (Except TRS-80 below) Al' Micropolis Mod I 01 Micropolis Mod II 02 MITS 3200/3202 B1 Morrow Discus AT Mostek Al MSD 5V4- .RC North Star Single Density Pi Norlh Star Double/Ouad P2 Nylac Single Density .03 NylacMicropolisMod.il 02 Ohio Scientific C3 A3 OnyxCaoOl T2# Pertec PCC 2000 AV Processor Technology Helios II ..B2 Quay 500 RO Ouay520 RP RAIR Single Density R9 RAIR Double Density RE * Single-Side Single-Density disks are supplied for use with Double- Density and DoubteSidc 8 soft sector format systems ■■ IMSAI formats are single density with directory offset of zero. # A media surcharge of S25 for or- ders on tapeformats T1 and T2 and of S100 for orders on disk formats Dl and D2 will be added. The list of available formats is sub- lect to change without notice. In case of uncertainty call to confirm the format code for any particular equipment Computar ayvtem Format Code Research Machines 8' At Research Machines 5'/4' RH REX .03 Sanco 7000 SW' RO SD Systems 8" Af SD Systems 5Vj' R3 Sorcerer See Exidy Sorcerer Spacebyte Al SuperBrain See Inteilec Tarbell Al' TEI 5V4' R3 TEIS" Al* Thinkettoys . . See Morrow Discus TRS-80 Model I 5Vr R2 TRS-80 Model I ^ FEC Freedom RN TRS-80 Model I t Mtcromation . .A4' TRS-80 Model I -i- Omikron 5Vi RM TRS-80 Model I -i- Omikron 8 . , Al TRS-80 Model I + Shuflleboard 8" Al TRS-80 Model II Al' VDP-40/42/44/80 See IMSAI Vector MZ 02 Versatile See CDS Versatile Vista V80 SVa" Single Density . . .P5 Vista V200 5^'4" Double Density .P6 Zenith Z89 -(■ Lifeboat CP/M . , . ,P4 Zenith 289 -i- Magnolia CP/M . . .P7 t Assodates . THE tsfrrw&BE MARKET " The So/fware Supermarket is a trademark of Lifeboat Associates Circle 80 on inquiry card. HANDLER CONCESSIONAIRES DISTRIBUIDORES 0,E,M, AUSGEZEICHNETE GROSS = HANDELSPREISE stellen nureinen Aspekt unseres Handlerprogrammes dar. Treten Sie noch heute mit uns in Vcrbindung. (Wir sprechen Deutsch) UN EXCELLENT PRIX DE GROS nc represente qu'un seul aspect de notre programme de distribution in- ternationale. Mettez-vous en contact avec nous aujourd'hui pour recevoir plus de renseignements. (On parle frangais!) EL EXCELENTE PRECIO AL MAYOREO que ofrecemos repre- senta solo un aspecto de nuestro programa de distribucion inter- nacional. Pongase en contacto con nosotros para informacion mas detallada. (Se habla espafiol!) A.D.D.S. ANADEX APPLE CENTRONICS CROMEMCO HAZELTINE IND. MICRO OKIDATA SO ROC SUPERBRAIN TELEVIDEO TEXAS INSTR. Micro-Computer Brokers INTERNATIONAL 66 1 9'P, North 2 1 si Auenue Phoenix, Arizona 850 1 5 U.S.A. Telephone: (602) 242-996 1 Telex: (0) 668382 Address 1 2 3 4 5 6 7 8 9 A B C D E F 000 00 00 00 00 00 00 00 00 04 02 7F 02 04 00 00 00 - 010 00 00 00 00 00 00 08 08 1C 2A 2A 2A 1C 08 08 00 020 00 00 00 00 00 00 00 3E 08 08 08 08 00 00 00 00 -k 030 00 00 00 00 00 00 22 22 22 3E 22 22 1C 00 00 00 PI 040 00 00 00 00 00 00 1C 10 10 10 10 10 10 10 10 00 L 050 00 00 00 00 00 00 oc 10 20 3C 20 10 oc 00 00 00 c 060 00 00 00 00 00 00 08 08 08 1C 2A 49 7F 08 08 00 ^ 070 00 00 00 00 00 00 00 00 08 14 22 41 7F 00 00 00 V 080 00 00 00 00 00 00 08 08 7F 49 2A 1C 08 08 08 00 4^ 090 00 00 00 00 00 00 04 08 08 08 08 10 00 00 00 00 \ OAO 00 00 00 00 00 00 00 00 18 24 24 18 00 00 00 00 OBO 00 00 00 00 00 00 7F 41 41 41 41 49 49 49 7F 00 □ OCO 00 00 00 00 00 00 7F 41 41 41 41 41 41 41 7F 00 D ODO 00 00 00 00 00 00 00 3E 08 08 08 3E 00 00 00 00 X OEO 00 00 00 00 00 00' 00 08 08 08 08 3E 00 00 00 00 T OFO 00 00 00 00 00 00 00 1C 22 41 49 41 22 1C 00 00 o 100 00 00 00 00 00 00 00 00 10 20 7F 20 10 00 00 00 *- 110 00 00 00 00 00 00 00 00 22 14 08 14 22 00 00 00 x 120 00 00 00 40 20 10 IE 11 11 OE 00 00 00 00 00 00 p 130 00 00 00 00 00 00 10 10 10 10 10 10 10 10 ic 00 r 140 00 00 00 00 00 00 00 01 IE 26 2A 32 3C 40 00 00 ^ 150 00 00 00 00 00 00 08 IC 2A 08 08 08 08 08 08 00 t 160 00 00 00 00 00 00 00 IC 22 35 49 6B 2A 1C 00 00 ® 170 00 00 00 00 00 00 00 08 00 00 7F 00 00 08 00 00 -r 180 00 00 00 00 00 00 00 00 08 14 22 41 00 00 00 00 V 190 00 00 00 00 00 00 08 08 08 08 08 08 2A IC 08 00 f 1A0 00 00 00 00 00 00 00 00 00 41 22 14 08 00 00 00 A 180 00 00 00 00 00 00 7F 41 49 41 7F 41 49 41 7F 00 S ICO 00 00 00 00 00 00 3E 00 04 08 10 20 10 08 04 00 < 1 DO 00 00 00 00 00 00 00 00 00 00 00 00 00 00 7 F 00 - 1E0 00 00 00 00 00 00 3E 00 10 08 04 02 04 08 10 00 > 1F0 00 00 00 00 00 00 00 40 20 7F 08 7F 02 01 00 00 ^ Table 1: Data that must be programmed into the 2708 erasable programmable read- only memory (EPROM) device. This data tells the video display how to form the APL characters from a dot matrix. To the left is the address of the data, in the center Circle 81 on inquiry card. 200 00 00 00 00 00 00 08 1C 2A 2A 1C 08 7F 00 00 00 ^ 210 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 220 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 230 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 240 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 250 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 260 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 270 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 280 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 290 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 2A0 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 2B0 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 2C0 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 2D0 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 2E0 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 2F0 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 300 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 310 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 320 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 330 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 340 00 00 00 00 00 00 4A 2E 20 57 2E 20 00 00 00 00 350 00 00 00 00 00 00 4C 61 6E 67 6E 65 72 20 00 00 360 00 00 00 00 00 00 57 42 32 4F 53 5A 2F 36 20 00 370 00 00 00 00 00 00 33 2F 34 2F 37 38 00 00 00 00 380 00 00 00 00 00 00 42 24 18 18 24 42 00 00 00 00 X 390 00 00 00 3C 02 02 3E 42 42 42 42 42 00 00 00 00 y 3A0 00 00 00 00 00 00 7E 20 10 08 04 7E 00 00 00 00 z 3B0 00 00 00 00 00 00 00 00 00 41 6A 15 08 00 00 00 A 3C0 00 00 00 00 00 00 08 08 08 08 00 08 08 08 08 00 ! 3D0 00 00 00 00 00 00 00 00 08 54 2B 41 00 00 00 00 v- 3E0 00 00 00 00 00 00 00 00 44 2A 11 00 00 00 00 00 - 3F0 00 00 00 00 00 00 7F 7F 7F 7F 7F 7F 7F 7F 7F 00 ■ is the data in hexadecimal in that row. form, and to the r ight is the character formed by the data H^ Pascal D SUPER-MICRO^" Executes Pascal 13x faster ttian an LSI-11 ! The SUPER-MICRO'" series of X-pert Systems!" designed by Computex, combine high perJormance with low cost. The X9000 system line features the Pascal MICROENGINE'- 16-bit CPU and is now avaiiable for deiivery. ■Tradeniark Western Digital Corp SYSTEM X9020 (CPU Manual $19.95) m95 READY TO RUN SYSTEM FEATURES (partial list) Pascal MICROENGiNE" X9000 • 16 bit P-codeCPU • 64K bytes RAM/Full DMA • Floppy disk controller (SS or OS) • Floating point hardware (IEEE standard) • Systemsoftware with enhancements • 2 serial, 2 parallel ports • Pascal compiler, text editors, file manager, CPU & memory diagnostics, symbolic Pascal debugger, linker, utilities and more. Floppy Disk Drives (2) • 1M combined memory • Double density, single sided • Standard 8" diskettes • 6 ms track to track SYSTEM X9023 ^^5095* PLUS. SYSTEM FEATURES (same as above) MODEL X-920 DISPLAY/EDIT TERMINAL x-920 FEATURES (partial list) (Manual $10) • Microprocessor controlled • SerlalRS232Cand 20 ma current loop • 10 baud rates— 75 to 19,200 • 24 lines X 80 characters • 12x10 character resolution • Dual intensity display • Programmable reverse video & underline • 14 key numeric pad with decimal • ISspecialfunction keys • 8 edit function keys • 2 block transmission keys • Block, protect & self-test modes • 80 stof able tabbing • Insert/deletecharacter and line • Addressable cursor • A host of other features, including cursor controls and remote commands such as: clear to nulls, spaces, end of line, end of screen; set hi, low, zero intensity; set blink, etc. •LIMITED TIME cash price. 10% DOWN guarantees priority. Master Charge & VISA cards accepted. Prices: X9000 CPU S2995. Manual S19.95. X-920 CRT S995. Manual SIO. Perkin-Elmer "Bantam" CRT S799. X-800 disk drive S495. Hardware F.O.B. Chicago. Manuals postpaid. Custom systems are also available. Weservlce what we sell. Written hardware warranty. Nationwide service contracts. Custom software. We provide expert technical support. (312)684.3183 COMPUTEX Microcomputer Systems X "The Computer Experts" 5710 Drexel, Chicago, IL 60637 September 1980 © BYTE Publications Inc 123 Photo 3: The APL character-generator circuit is connected by a ribbon cable to the socket formerly occupied by the MCM6571 part on the video display board. Use of sockets enables you to unplug the APL character-generator circuit and plug the MCM6571 back into the video display board if you need to reactivate the Greek characters. Hexadecimal Code Old Character New Character Hexadecimal Code Old Character New Character 00 a - 10 p - 01 B * 11 a- x 02 7 JL 12 T p 03 8 PI 13 V r 04 « L 14 ^ ^ 05 c c 15 X i 06 •7 i 16 t © 07 6 V 17 01 ^ 08 t 4^ 18 n V 09 If \ 19 J~ f OA X o 1A - A OB ^ □ IB *- B oc V n 1C t < OD e I ID 4- - OE T IE I > OF w o IF 60 7B 7D ( ) -A- Table 2: Table of character substitution to swap the APL characters for the Greek used characters in the MCM6571 character-generator chip. alph abet and oth er seldom- 124 September 1980 © BYTE Publications Inc Circle 82 on inquiry card. icaiYiRJTHQi^iics; EVERYTHING 50 N. PASCACK ROAD SPRING VALLEY, NEW YORK 10977 ■*£: APPLE IS A TRADEMARK OF THE APPLE CORP. FROM COMPUMAX BUSINESS SYSTEMS The COMPUMAX business applications programs are written with the novice computer user in mind. They are easy to use, yet powerful in their capabilities. Further. COMPUMAX supplies the BASIC source code. Thus the programs are easy to modify. MICROLEDGER This General Ledger system performs the essential functions of dual entry bookkeeping and matches revenues and expenses: MICROLEDGER includes the following programs.: LEDGER 1 - builds and maintains the CHART OF ACCOUNTS file. This file contains both current and accumulated totals for each account. LEDGER 2 - builds and updates the JOURNAL TRANSACTION file. LEDGER 3 - lists both the the JOURNAL file and the CHART OF ACCOUNTS. LEDGER 4- computes the TRIAL BALANCE andexecutes POSTING of journal trans- actions into the CHART OF ACCOUNTS. An AUDIT TRIAL of all transaction is output. LEDGER 5 - produces the PROFIT AND LOSS STATEMENT. LEDGER 6- produces the BALANCESHEET. Assets, liabilities and owners' equities are shown by account and by totals $140.00 MICROPAY An Accounts Payablesystem, MICROPAY includes the following program & functions: PAY 1 - initializes bothTransaction and Master files, then beginstheAccounts Payable process by inputting and adding records in the Transaction file. PAY 2 - allows for changes and deletions of Transaction and Master records. PAY 3 - reports outstanding Accounts Payables in four categories: under 30 days. 31-60 days, 61-90 days, and over 90 days. PAY 4 - reports all outstanding Accounts Payables for a single customer or for all custo- mers, and computes Cash Requirements. PAY 5 - reports all outstanding Accounts Payables for a single date or for a range of dates and computes the Cash Requirements. PAY 6 - lists both the Transactions and Master files. PAY 7 - prints checks and accumulates and journalizes Accounts Payables. This pro- gram simultaneously creates entries for the MICROLEDGER file $140.00 MICROREC An Accounts Receivable system. MICROREC includes the following programs and functions: REC 1 - initializes Accounts Receivable files, adds A/R record and prints invoices. REC 2 - accepts receipt of customer payments and changes or deletions of A/R Trans- action or Master file records. REC 3 - reports outstanding Accounts Receivables in four categories; under 30 days. 31-60 days. 61-90days. and over 90 days. REC 4 - reports all outstanding Accounts Receivables for a single customer, or for all customers and computes Cash Projections. REC 5 - produces reports for all outstanding Accounts Receivables for a single date or for a range of dates and computes Cash projections. REC 6 - lists Transaction and Master files and accumulates and journalizes Accounts Receivables, creating JOURNAL entries which communicate with the MICROLEDGER JOURNAL file $140.00 MICROINV This Inventory Control system presents a general method of Inventory Control and pro- duces several important reports. Its program includes; INV 1 - initializes Transaction and Master files and adds and updates Transaction and Master records. INV 2 - handles inventory issued or received, creating inventory records. This program also accumulates and journalizes transactions, producing JOURNAL entries which communicate with the MICROLEDGER file. INV 3 - lists both Transaction and Master files. INV 4 - produces the STOCK STATUS REPORT, showing thestandardinventory stock data and stock valuation, and the ABC ANALYSIS breaking down the inventory into groups by frequency of usage. INV 5 - gives a JOB COST REPORT /MATERIALS, showing allocation of materials used year-to-date by each job or work code. (This is complemented by the Job Cost Report/ Personnel in the MICROPERS program.) INV 6 - computes and provides the E.O.Q. (Economic Order Quantities) $140.00 MICROPERS This is a Payroll/Personnel program whose functions include; PERS 1 - initializes the Master file and allows forentry and updates of Master records. PERS 2 - initializes the Payroll file and allows for entry and updates of payroll records. PERS 3 - lists an Employee Master Record or the entire Employee Master file; lists a single Payroll Record or the entire Payroll file. PERS 4 - computes Payroll and prints the PAYROLL REGISTER. Prints PAYCHECKS and creates JOURNAL entries to be fed into the MICROLEDGER JOURNAL file. PERS 5- produces the JOB COSTREPORT/PERSONNEL. computes the quarterly 941 bank deposit, and the Annual W-2 run $140.00 All COMPUMAX programs available in machine readable format (diskette form) for the following machines: TRS-SO'" Model I Micropolis 1053/11 APPLE II Microsoft under CP/M PET CBASIC under CP/M Cromemco FROM ADVENTURE INTERNATIONAL (By Scott Adams) t 1. ADVENTURELAND - You wander through an enchanted world trying to recover the 13 lost treasures. You'll encounter wild animals, magical beings, and many other perils and puzzles. Can you rescue the Blue Ox from the quicksand? Or find your way out of the maze of pits? Happy Adventuring t 2. PIRATE'S ADVENTURE - "Yo ho ho and a bottle of rum" You'll meet up with the pirateand his daffy bird along with many strange sights asyouattempttogofrom your London flat to Treasure Island. Can you recover Long John Silver's lost treasures? Happy Sailing, matey 3. MISSION IMPOSSIBLE ADVENTURE - Good morning, your mission is to... and so it starts. Will you be able to complete your mission in time? Or is the world's first automated nuclear reactor doomed? This one's well named. It's hard, there is no magic, but plenty of suspense. Good luck 4. VOODOO CASTLE - Count Cristo has had a fiendish curse put on him by his enemies. There he lies, with you his only hope. Will you beabletorescuehim oris he forever doomed? Beware the Voodoo Man ..... * Ait orders processed within 24'Hours * 30'Da\^ money; back guarantee on all Software (less a $3 penalty for handling) 5. THE COUNT - You wake up in a large brass bed in a castle somewhere in Tran- sylvani. Who are you. what are you doing here, and WHY did the postman deliver a bottle of blood? You'll love this Adventure, in fact, you might say it's Loveat First Byte 6. STRANGE ODYSSEY - Marooned at the edge of the galaxy, you've stumbled on the ruins of an ancient alien civilization complete with fabulous treasures and unearthly technologies. Can you collect the treasures and return or will you end up marooned forever? 7. MYSTERY FUN HOUSE -Can you find your way completely through the strangest Fun House in existence, or will you always be kicked out when the park cfoses? . . . 8. PYRAMID O F DOOM - An Egyptian Treasure Hunt leads you into the dark re- cesses of a recently uncovered Pyramid. Will you recoverall thetreasuresormore likely will you join its denizens for that long eternal sleep? 9. GHOST TOWN - Explore a deserted western mining town in search of 13 treasures From rattlesnakes to runaway horses, this Adventure's got them all! Just remem- ber, Pardner, they don't call them Ghost Towns for nothin'. (Also includes new bonus scoring system!) $14.95 Per Adventure * Note: Apple requires 24K and has no lower case. t Recommended for the novice adventurer, with many built-in HELPS! FROM PERSONAL SOFTWARE (NC. VISICALC $150.00 Take virtually any problem you would explore using calculator, pen, and paper, working in rows and columns. Apply VisiCalc and you'll see why every reviewer of this producthas said thesame thing; VisiCalc isthe most useful, most important program yet developed for personal computing. With VisiCalc. you work with an electronic worksheet of up to 63 columns and 254 rows. At the juncture of any column and row you can type in words and numbers. VisiCalc automatically performs all arithmetic functions, net present value, and transcendental functions - instantly! CCA DATA MANAGEMENT SYSTEM $74.95 DMS Features: File Creaton and Maintenance; • Fields may be alphanumeric, numeric, integer, floating point, or fixed decimal with commas. • Fields may be COMPUTED FIELDS. DMS will compute any field within a record, using constants or other fields in the same record. Functions include add, subtract, multiply, divide, and raise exponential powers. • Records are easily located, using the SCAN feature. SCAN for records with afield over, below, or between a range of values. • Records are easily added and updated. DMS "prompts" you with questions, • Multi-diskette capabilities for larger files - up to 85.000 characters per file! • Sort the records into almost any order, using up to 10 fields as "keys". So you can sort for customer numbers; within zip code, for instance. • Delete records, "compact" files, and backup files on data diskettes easily. Report Features: • Print reports with records in any order. • Select fields to be printed. • Print mailing labels. • Numeric totals and subtotals can be specified when a value in an unrelated field in the same record changes. For example, sort, subtotal, and print according to depart- ment, or month, or customer number, or model number. GUAl ,B;vNTeeDPBOF.T ^^^^^ WINS PLACES SHOWS 32% AVERAGE PROFIT AT ALLTRACKS-1978 THE HORSE SELECTOR II (FLATS) (By Dr Hal Davis) $50.00 New simplified version of the original Horse Selector. The first Horse Selection System to actually calculate the estimated odds of each horse. HIGHER PROFITS (OVER 100%) POSSIBLE THROUGH SELECTIVE BETTING ON; • Rates each horse in 10 seconds. • Easy to follow rules. • Can be used with any Apple II Computer. • 100% money back guarantee (returned for any reason). • Uses 4 factors (speed rating, track variant, distance of the present race, distance of the last race) • Using the above factors, the Horse Selector calculates the estimated odds. BET on horses whose actual payoff (from the Tote Board or Morning Lines) is higher than payoff based on estimated odds. • Using the above factors, the HorseSelector calculates theestimatedodds. BET on any selected horse with an estimated payoff (based on Tote Board or Morning Lines) higher than calculated payoff (based on Horse Selector II). • Source listing fortheTRS-80'". TI-59, HP-67. HP-41, Appleand BASIC Computers. • No computer or calculator necessary (although a calculator would be helpful for the simple division used to calculate estimated odds) FREE Dutching Tables allows betting on 2 or more horses with a guaranteed profit. HOUR OA ORDER LINE (914) 425-1535 ADD $2.00 FOR SHIPPING UPS AREAS ADD $3.00 FOR COD. OR NON-UPS AREAS ADD $4.00 OUTSIDE U.S.A. CANADA & MEXICO NEW TOLL-FREE ORDER LINE (OUTSIDE OF N.Y. STATE) (800) 431-2818 Construction of a Fourth- Generation Video Terminal: Part 2 Theron Wierenga POB 2007 Holland MI 49423 Last month in Part 1, I presented the first part of a complete plan for building a versatile, microprocessor- controlled video terminal. Now we'll look at the rest of the construction details. We stopped at the point of troubleshooting the 8085 microprocessor and related circuitry. If your tests with oscilloscope and fre- quency counter show that everything built so far checks out properly, you can proceed with the remainder of the construction. Getting the Debug Monitor Operating The next step is to install the four 2114 memory circuits, IC19 (the 74LS138 that decodes the 2114s), IC13 (the 7401 that is used with the 74LS138 decoder), and IC4 and IC5 (the two 8212s that are connected back-to-back to buffer the 2114s). The 2716 must be programmed again, this time with the entire software The numbering sequence of figures, listings, and photos is continued from Part 1 of this article. package that is given in listing 2. Before continuing, let me define some terms that are frequently used in the next section. Figure 4 on page 128 is a block diagram relating a number of these terms. • Host computer: the computer to which your completed video ter- minal will be connected. It will operate completely independently of the terminal circuitry. Com- munications between the host computer and the video terminal will be via a serial interface driven by UARTs. • 8085 microprocessor: the com- puter that will control the internal operation of the video terminal. • Checkout terminal: any standard computer terminal with a current- loop interface that will be used to debug your video terminal's hard- ware and software. • Temporary interface: a simple cir- cuit that must be built to tem- porarily connect your video ter- minal to the checkout terminal. • Terminal control software: the software that directs the 8085 in the procedure of controlling the terminal. It operates the display and takes care of incoming characters and scrolling. This soft- ware resides in the 2716 program- mable read-only memory. • System monitor: a separate operating system that resides within the terminal control soft- ware. When this monitor is used, the 8085 microprocessor "aban- dons" the video terminal circuitry, and then behaves as a separate computer for the checkout ter- minal. The monitor allows the user to load and display memory loca- tions, run simple programs, and fill and move blocks of data in the memory. The data transfer lines to the host computer are not con- nected when using the monitor. Activating the Monitor In normal operation the 8085 operates as a dedicated micropro- cessor. This means that the micro- processor's total job is to operate the display and process incoming characters. The 2716 programmable read-only memory can hold 2048 bytes of program code. Only about 1500 bytes are needed for the terminal control software, so a portion of the 126 September 1980 © BYTE Publications Inc What's the difference between B^sic and Biscal? COMPARE THESE APPROACHES TO DRAWING A CIRCLE m BASIC "This is easy ...' loo MOVS" R>0 (Bo M^T T "Oops, didn't quite meet . . . . . . hut that's easy to fix. ' 100 WHS R^O \ 10 FOR T«o -n: s^c'sTE^pfc ^ts* j20 DRAW R^^<»SCO) R^SlNl^-n 130 N^KTT "O/i, now it closes . . . in fact, it overlaps. " Programming by trial and error in Pascal "The simplest circle drawn with line segments is a regular polygon ..." procedure Circle (X, Y, Radius: real); const Sides = 16; Pi = 3.14159265; var N : integer; Theta : real; begin Move (X+Radius,Y); for N : = 1 to Sides do begin Theta : = 2 * Pi * (N/Sides); Draw (Radius * cos (Theta) + X, Radius * sin (Theta) + Y); end; end; Programming by design GET IT RIGHT THE FIRST TIME INTERNATIONAL DISTRIBUTORS Australia: Sydney Network Computer Services 290-3677 Canada: Vancouver Valley Sof tv^are (604) 291-0651 England: London Real Time Products 01-588-0667 Japan: Tokyo Rikei Corporation 03-345-1411 Circle 83 on inquiry card. If you like the feel of precision tools, give us a call or return this coupon. by9 Name Firm • • Software Address City 2340 SW Canyon Road • Portland, Oregon 97201 (503) 226-7760 • TWX 910-464-4779 State -Zip . BYTE September 1980 127 Circle 84 on inquiry card. CHOOSE... Choose an Apple Desk A compact bi>ievel desk ideal for an Apple computer system. This 42"x 3V/4" desk comes with a shelf to hold two Apple disk drives. The top shelf for your TV or monitor and manuals can also have an optional paper slot to accom- odate a printer. Choose a Micro Desk Getyour micro computer off the desk top and into the micro shelf under our Designer Series desks. Suitable for the North Star, Dynabyte, Vector Graphics, and Altos computers. The desks come in a variety of sizes and colors. Choose a Mini Rack Mini racks and mini micro racks have standard venting, cable cutouts and adjustable RETMA rails. Choose a stand alone bay or a 48", 60", or 72" desk model in a variety of colors and wood tones. A custom rack is available for the Cromemco. Choose a Printer Stand The Universal printer stand fits the: Centronics 700's Diablo 1600's & 2300's Dec LA 34 T.I. 810 & 820 NEC Spinwriter Okidata Slimline Lear Siegler 300's Anadex 9500's Delivery in days on over 200 styles and colors in stock. Dealer inquiries invited. ELECTRONIC S'dSTEMS FURNITURE COMPylN'd 17129 S. Kingsview Avenue Carson, California 90746 Telephone: (213)538-9601 HOST COMPUTER VIDEO TERMINAL 8085 MICROPROCESSOR n TEMPORARY INTERFACE CHECKOUT TERMINAL L. .J Figure 4: Block diagram of the connection of the video terminal to the host computer. Also shown are the temporary connections to the checkout terminal, used for debugging the project. additional memory has been filled with a completely separate operating system which is termed the system monitor. By causing the 8085 microprocessor to execute a TRAP in- terrupt, a jump is made to the section of memory wherein the system monitor resides. In this mode the 8085 microprocessor and its associated circuitry cease to control the video terminal circuitry. The 8085 now behaves as a simple computer with a system monitor. Another ter- minal, the checkout terminal, is necessary to communicate with the system monitor; the temporary inter- face is also necessary to connect to the checkout terminal. Construct this interface for tem- porary use by breadboarding. A schematic diagram was shown in figure 3, part 1. Any general-purpose computer terminal with a 20 mA current-loop interface can now be connected to your video-terminal board. The 8085 microprocessor will be acting as a computer for the checkout terminal. Be sure that the data rate is the same for both devices. If your checkout terminal runs at 110 bps, you will have to temporarily connect a 7040 Hz square wave into pins 9 and 25 of the 8251 (IC7), since this frequency is not available on the video-terminal board. When all connections to the tem- porary interface are made, open the TRAP switch for a moment. The 8085 microprocessor should send a car- riage return, line feed, and question mark to your checkout terminal. Next, type a letter D, and the ter- minal should perform a carriage return and line feed. Now type in four Os, and it should again perform the carriage return and line feed. Lastly, type in "003F" and the checkout ter- minal should print out four lines of memory contents. If you get to this point, congratulate yourself, take a break, have a glass of wine, and show the family you're not as crazy as they thought you were to start this project. If you were able to get the first test program to send out "U" characters. Text continued on page 152: 128 September 1980 © BYTE Publications Inc Circle 85 on inquiry card. k I A Small-Systems Breakthrough! I UDS Line-Powered Data Modems 0-300 bps full-duplex (Model 103 LP) orO-1200 bps half-duplex (Model 202 LP) over ordinary two-wire telephone circuits No AC power required Fits under your telephone handset Easy hook-up Simplified controls — talk/data only Direct connect to dial-up network Better data integrity than acoustic couplers at the same (or lower) price Patent Applied For Your telephone, combined with a UDS 1 03 LP or 202 LP modem, can put your computer system in contact with the rest of the DP world. Make three easy snap-in cable connections and either of these FCC- approved devices is ready to go on-line. A front-panel rocker switch lets you go from voice to data and back again whenever you wish. Either the 103 or the 202 fits comfortably under your telephone — you'll hardly know the modem is there. The UDS units are compatible with Bell103- and 202-series modems. SPECIFICATIONS OPERATION — f ull>duplex (Model 1 03 LP) or half -duplex (Model 202 LP) on two-wire dial- up telephone circuits. DATA RATE - 0-300 bps (Model 1 03 LP) or to 1 200 bps (Model 202 LP). DIGITAL INTERFACE ~ RS-232C on both models; IT Y current loop on Model 1 03 LP CONTROLS AND INDICATORS - Data/Talk switch; data ON light emitting diode. DISTRICT OFFICES: Summit, N J, 201/522-0025 • Blue Bell, PA, 215/643-2336 • Atlanta, 404/952- 3463 • Chicago, 31 2/441 -7450 • Dallas, 21 4/385-0426 • Santa Ana, 71 4/972-461 9 • Sunnyvale, 408/738-0433 • Boston, 617/875-8868 "Confidence in Communications' Universal Data Systems 5000 Bradford Drive • Hunts ville, AL 35805 • Phone 205/837-8100 Created by Dayner/Hall, Inc., Winter Park, Florida ^^R- Z. 2 3 LlI LlI 3 C L^ ij^ LlI UJ in C ill <1-o >ax XCJU-U-CCCCC 2 liJU CJ ccKCixrv jiL^cn X CE CD ID C " »-»-cjuciiC!! -icncju"; cnoccr-u_»-»- Cuicnr-j i-iS;_i_i G C CJZJLiJCC C-- i- »- i- iX- CJ CCCC2 2 C C C LLiii:ii:i>;ii:i-:j-i-:5- uiJ-LiiLc: tnLLiLLiLi.LLiCLLiGLij LULULLiLLi > > > 2 I-i 1—: in Ci iX- iX- X- iX C h- »- in in 1—: H- : 1—: UJ > - 0; cn K cn - LL cn en CJ fN f^ ^-H CD bo c: a. 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G c/: G it it it LU G G N G c/: G C- 2 I- G G * it * I- LU -I 2 N O U U 3 PQ G G it U- 2 !- HH Ll LU it _! :L !- LU LU li 3 LU X G 2!-NLUGNG_! _ G>- }- it XGXlC GPQI->- [-•'GLl G h-igQX>-iO ^_1 3 3 G I- -! GGC/^LLi-iC/^LLLUG"*! LC:— ih-ih-iXh-ii-iCni-G G it G 3 G 2 LU H^ !- X 2 i- 2 i- ^^ G X G i-i _i G O G 3 Lii CD G i- i\ it a: it 2 G - ui _! 3 G X G h-i h-iI- h-iNZ>h-i h-iH'CC^ - IV - I- I- Ron Williams Control Data Corporation, P.O. Box HQA02J, Minneapolis, MN 55440 Send information on the following courses: D Accounts Receivable Collection Techniques n Selling; The Psychological Approach n Managerial Success D General Information D Others 6980 Name- -Title _ Company^ Address^ _Phone_ '■^^ City. I...- -State _ -Zip- Circle 356 on inquiry card. 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C Lii U O Ll U C LU U Ll c vo r-< ^ ^H Li: \l- bo :> C^ a. in ? Lii ^ 3: 3 Lii en en c C -O >c >c >c >c >c b"; 00 ro >G >c n m in -H r-^ rs c ii; >C C> C U rs u CJ U U >c u ^• u C Lii U C Ll U CJ u Ll r-^ r*^ >c I^ c FN III LlI r-^ l:; CD \n >c o >c >c >c >C SD N i^ fN [\ fN. r\ fs. r\ CD CD Cr CT >c >c >c >c >c >c >C >C >C >C >C >c >C ^- >C ^- >C >c >c >c 000 00000 00000 000 U C O ^ r-^ t--^ >C C> C r- C FN o lii Lii O r-^ L:; CD C^ c sd n i^ r^ [\ rv r\ r\ !\ cd cd ex: cr cd cd cr cd c^ cn cn cn cs cn cn c <;• <:• <:• <:• <:• vd sd sd o- sj o- sd >c sd sd ^- <;• >c <;• ^- sj <;• <;• s: >c >c sj o- sd o- <;• <;• >c >c s: >c <;• 00000000000 000000 000000 00000000 000000000000 lli r llJ en en i-i liJ c ■ U hO in u C >C CD 148 September 1980 © BYTE Publications Inc Exciting, entertaining software for the Apple II and Apple II Plus' If you liked "Invaders", you'll love ASTEROIDS IN SPACE by Bruce Wallace. Yourspaceship is traveling m the middle of a shower of asteroids. Blastthe asteroids with lasers, but beware — big asteroids fragment into small asteroids! The Apple game paddles allow you to rotate your space ship, fire its laser gun, and give it thrust to propel it through endless space. From time to time you will encounter an alien space ship whose mission is to destroy you, so you'd better destroy it first' High resolution graphics and sound effects add to the arcade-like excitement that this program generates. Runs on any Apple II with at least 32K and one disk drive. On diskette — $19.95 FRACAS'" by Stuart Smith. A fantastic adventure game like no other — up to eight players can participate in FRACAS at the same time. Journey in the land of FAROPH.searchmgforhiddentreasurewhile warding off all sorts of unfriendly and dangerous creatures like the Ten Foot Spider and the Headless Horseman, You and your friends can compete with each other or you can join forces and gang up on the monsters. Your location is presented graphically and sound effects enliven the battles, Save your adventure on diskette or cassette and continue it at some other time. Requires at least 32K of RAM. Cassette: $19.95 Diskette: $24.95 BATTLESHIP COMMANDERS" by Erik Kilk and Matthew Jew. A game of strategy. You and the computer each start out by positioning five ships of different sizes on a ten by ten grid. Then the shooting starts. Place your volleys skillfully — a combination of logic and luck are required to beat the computer. Cartoons show the shipssmkingand announce the winner. Sound effects and flashing lights also add to the enjoyment ol the game. Requires at least 32K of RAM, Cassette: $14.95 Diskette: $19.95 FASTGAMMON'" by Bob Christiansen. Sound, hi res color, and cartoons have helped maked this the most popular backgammon-playing game for the Apple II. But don't let these entertaining features fool you — FASTGAMMON plays serious backgammon. Requires at least 24K of RAM. Cassette: $19.95 Diskette: $24.95 *"Apple IT' and '"Apple II Plus" are trademarks ol Apple Computer, Inc QUTiLrry sorrwTiRe 6660 Reseda Blvd., Suite 105, Reseda, CA 91335 WHERE TO GET IT: Call us at (213) 344-6599 for the name of the Quality Software dealer nearest you. If necessary, you may order directly from us. MasterCharge and Visa cardholders may place orders by telephone and we will deduct $1 from orders over $19 to compensate for phone charges. Or mail your order totheaddress above. California residents add 6% sales tax. SHIPPING CHARGES: Within North America orders must include $1.50 for first classshippmg and handling. Outside North America the charge for airmail shipping and handling is $5.00 — payable in U.S. currency. Circle 93 on inquiry card. BYTE September 1980 149 Circle 94 on inquiry card. :.:x: CP/A OPTIMIZED SYSTEMS SOFTWARE PRESENTS CONTROL PROGRAM/APPLE the DOS you have been waiting for OSS CP/A is an all new, disk-based operating system which provides commands and utilities similar to CP/M®. CP/A has byte and block I/O, a simple assembly language interface, and direct access via Note and Point. And it's easy to add your own com- mands or device handlers. CP/A is expandable, flexible, consistent, easy-to-use and available now with compatible program products: BASIC — Some of the features of OSS BASIC are syntax checking on program entry, true decimal arithmetic (great for money applications), 32K byte string sizes, flexible I/O, long variable names (up to 255 significant characters), and the ability to get and put single bytes. BUSINESS BASIC WITH PRINT USING— This is virtually the only basic available on the Apple that has PRINT USING. It also has record I/O statements and all the features of our standard BASIC. EDITOR/ASSEMBLER/DEBUG — OSS EASMD is a total machine language de- velopment package. The editor provides functions like FIND, REPLACE, etc. The assembler uses standard 6502 mnemon- ics, can include multiple files in one assem- bly, and can place the object code in memory or to a disk file. Prices of CP/A with: BASIC $ 69.95 Business BASIC 84.95 EASMD 69.95 BASIC -H EASMD 109.95 Business BASIC + EASMD .... 124.95 Requires 48K RAM and DISK Add $3.50 for shipping and handling in continental USA. California residents add 6%. VISA/Master Charge wel- come. Personal checks require two weeks to clear. SEE YOUR DEALER or ORDER TODAY OPTIMIZED SYSTEMS SOFTWARE is a product of Shepardson Microsystems, Inc. 20395 Pacifica Dr., Suite 108B Cupertino, CA 95014 (408) 257-9900 Listing 2 continued from page 148: GAFF r:DDf)06 CALL ZIN 0702 47 MOU B y A 0703 70 xx: MOU rWB 0704 23 TNX H 070!:; 7C MOU A f H 070A BA CMP H 0707 C20307 JN7 XX 070A 70 MOU A , L 070B BI^ CMF' 1:: 070(: C 20307 JN7 XX 070F C9 RET ; Bl. or.K M 0710 1603 moue: • MUI n r 3 0712 Cri6B06 BKh : CALL I NAD 0715 F!=i PUSH H 0716 15 DCR n 0717 C2I207 JNZ BKi'i 071A El POP H 071B CI POP U 071C 03 INX B 07 ID Dl POP D 071E lA BK7: LDAX Tl 07 IF 77 MOU Mf A 0720 13 INX D 0721 :;>:^ INX H 0722 7 A MOU AfD 0723 B8 CMP B 0724 C21E07 JNZ BKZ 0727 7B MOU ArF 0728 B9 CMP r: 0729 C21E07 JNZ BKZ 072 c: r:9 RET MQUE IN i-iEi-i VARIABLE STORAGE 87D2 ORG 87t:»:;>h 0001 cctad: DS 1 0002 rctad: m 2 0001 CURSY : DS 1 80 MACRO ASSEMBLER » UER 2*0 ERRORS " PAGE 2^ 0002 TOP AD : ns 2 0002 locad: DS 2 0002 Locoi: DS ';) 0002 Locoo: ns 2 0002 Locxx: DS 2 0002 locpr: DS 2 0002 LOCBUF :ds 2 0001 XFLO: DS 1 0001 uschr: DS 1 0002 botad: END DS 2 NO PROGRAM ERRORS L 8080 MACRO ASSEMBLER r UER 2*0 ERRORS = o PAGE 2= 1 SYMBOL TABLE * 01 A 0007 AGGIE 00D2 ALPH 0142 ALPHA 0046 B 0000 Bl 0647 B2 063E BETA 014C BILBO 0216 BKM 0712 BKZ 071 E BOTAD 87E6 BSETl 04C1 BSET2 04E1 BSET3 04E9 C 0001 CCTAD 87D2 CCTMA 01C4 CCTMB 01 CD CCTOA 019 4 CCTOB 019D CHREC OOEl CNCTL 0001 CNIN 0000 CNOUT 0000 CNTRL 0123 COLLT 0322 COL.RT 032A COMRT 03 DC COMRX 0220 COMRY 02E4 CR 06A3 CRCOM 0051 CRDAT 0050 CRTGO 0040 CTA 0350 CTB 0360 CTC 036D CTRl.H 02FB CTRLJ 02EF CTRL.M 02F2 CURSY 87D5 n 0002 DELTA 0172 DISl 0374 DISA 03B1 DISB 03B9 DISC 0300 DISPL 0341 tiUCK 041E DUMP 0636 DUMY 04C0 E 0003 EORT 03F1 ESCA 0135 ESCB 015B ESCC 0179 ESCD 01A9 ESCE 022B ESCH OlEl ESCJ 025C ESCK 01F3 ESREC OlOB FIL 06F3 FILL 0426 FIN 027F FRODO 020A FUN 02C2 GAMMA 0168 GNOME 02A1 GZONK 02B3 * H 0004 INAD 066B KCOM 0061 KDAT 0060 Listing KF'OL.L 2 continued 04A0 on page 152 150 September 1980 © BYTE Publications Inc Announcing the music card that turns you into a Rock Star. Girls will climb aver each other to kiss your feet. musical instrument — real or imagined". Sure. Before you listen to their claims, listen to their music. That's Some companies will say anything to sell you a music musical instrument — real or imac card. One is "designed by leading experts". One's called you listen to their claims, listen tc the "Super Sound Generator". Another is "part of the where the real differences show up excitement of owning a personal computer". Then there's the one with "flash & crash sound effects". And ■ *^ ^ how about the one that "generates the sound of any .~ — ^ tlx y^, > xj , You can hear our music card at your local Apple dealer. w ¥\ V-. « Or, just send us $1 and we'll send you a demo record of our 9 voice card. When you listen to a music card, ask if the song you're hearing was programmed by a customer, or by experts at the company that made the card. Was it done with the software ypuMI ;get, or with special programming? Over half the songs on our demo record were entered by customers using the soft- ware supplied with the card - you can do it the same way. Our rhanual shows you how step by step. The "Apple Music ir has 9 voices and is just $195 * . The "Apple Music Synthesizer" has 3 top-quality voices for just $265*. ^ See your local Apple dealer, I or write for more details. Bill Fickasjleaij guitar fo the Broken Rubber Band. Quality computer music products since 1975. ALF PRODUCTS 1448Estes ^ Denver, CO 80215 (303)234-0871 'Suggested U.S. price. Listing 2 continued from page 150: L 0005 LOAD 0623 LOADX 0235 LOCOl 87DA L0C80 87riC LOCAD 87D8 LOCBU 87E2 LOCPR 87E0 LOCXX 87DE LOOP OOBE M 0006 MriC57 0000 MriS57 0084 MOVE 0710 NUF 02DA NXT2 0055 NXTA 01B5 NXTCM 0397 NXTX OOED NXTY 00F9 NXTZ 0105 OUTAD 065F PC2&A 0044 PC2TC 0045 PC3SA 0046 PC3TC 0047 F'MD57 0048 F'SU 0006 RCTAD 87D3 RriF51 00D9 ROUDN 0310 ROUUP 02FE RT75 0467 SCROL 03FF SIN 0677 SOUT 0689 SF" 0006 SSS2 05E9 START 05F6 Tl 0626 TOPAD 87D6 TROLL 0297 USCHR 87E5 USZ 04B5 VAR 0273 UIZAR 02CB UP75 0332 X7 0659 X8 0655 XFLG 87E4 XIN 06AE XMIT 04A9 XOUT 06C6 XSTAD 03A3 XX 0703 XY 0698 Zl 06C11 ZETA 0185 ZIN 06D5 ZOUT 06E6 Photo 6: The complete terminal system with keyboard, monitor, power supply, and main circuitry. Text continued from page 128: but you cannot get the monitor operating with the checkout terminal, then most likely your problem is in the 2114 programmable memories, the decoder circuitry for the 2114s, or the 8212 buffers for the 2114s. Other problems could be caused by the tem- porary interface or data rates that dif- fer. Using the Monitor After your built-in monitor is working, you can jump to it for use in debugging the remainder of the cir- cuit. Opening the TRAP switch will cause the 8085 microprocessor to transfer control to the monitor. To return to the terminal-control soft- ware, the 8085 microprocessor is reset. To facilitate this, I have con- nected the BREAK switch on my keyboard to the 8085 RgSET IN' line (pin 36). This connection is also useful for resetting the video terminal just after it is turned on, or for easy 152 September 1980 © BYTE Publications Inc clearing of the screen. One of the most useful functions of the system monitor is its ability to load into memory and run short programs that will read the status registers of the peripheral circuits to determine whether or not they are operating properly. This includes the 8251, 8257, 8275, and the 8279 integrated circuits. The system monitor commands are as follows: D (Dump): Type the letter D followed by two 4-digit hexadecimal numbers that represent addresses in the system. Memory contents be- tween the two addresses will be printed on the checkout terminal in hexadecimal with 16 bytes on a line. The line will begin with the address of the first byte in that line. A dump can be aborted by pressing the ESC key. F (Fill): To fill a block of memory with a specified value, type an F followed by two 4-digit hexadecimal addresses which are the inclusive locations in memory to be filled. Last- ^Y/ type the 2-digit hexadecimal number that the block of memory is to be filled with. G (Go): Typing a G followed by a 4-digit hexadecimal address will transfer that address to the program counter, and program execution will continue from that location. After a short program has been loaded into memory, the Go command can transfer execution to this program. L (Load): To load sequential memory locations with arbitrary values, type an L, followed by a 4-digit hexadecimal address. The system will prompt the user with se- quential addresses, after which the user can type in the desired contents in the form of 2-digit hexadecimal numbers. You can exit from the load routine by typing any nonhexa- decimal character. M (Move): The Move command can write blocks of data from one memory location to another. After the M is typed, three 4-digit hexa- decimal addresses must be typed in. The first two addresses enclose the block of data in memory to be moved, and the third address is the beginning location of the area where the block of data is to be written. Any time a character other than D,F,G,L, or M is typed in response to the "?" prompt, the monitor will simply reissue the prompt character. When the appropriate response should be a hexadecimal character and another character is typed in- stead, the monitor will cancel the command and reissue the prompt character. No carriage returns are necessary after typing in data to the system monitor. When the monitor has the correct amount of data it will execute the command. Keyboard Assembly I used the sixty-three-key unencod- ed keyboard offered by Jameco Elec- tronics, 1021 Howard Ave, San Carlos CA 94070. The cost was $29.95. This is a good-quality keyboard for the price. Each pair of switch contacts protrudes from the bottom of the keyboard by about an eighth of an inch, making it necessary to mount the unit on a printed-circuit board. Because of the complexity of the switch matrix, a complete printed-circuit layout would have to Text continued on page 156 YOU'RE A GENIUS FOR BUYING DMASTAR. But you don't have to be one to use it. Now, from those wonderful folks that brought you WordStar,™ comes DataStar ™ A general purpose key to disc data entry software package you don't have to be a graduate from M.I.T. to operate. DataStar makes life a breeze because DataStar makes data entry and verification a breeze. It has two distinct phases. One allows you to actually design on the CRT the exact form you need. Just name the job. If it can be done on a CP/M'^' based micro- computer, then DataStar can do it. From handling inventory and billing to entering names in the office football pool. How's //z^/" for flexibility! The other phase allows you to store and retrieve data. All kinds of data. Quickly and accurately. Which also allows you a chance for that second coffee break, you genius you. And don't worry, DataStar makes sure that what you put into the system is right; because even a genius like you can sometimes make a mistake. So go ahead. Let DataStar bring out the genius in you. Simply call us at (415) 457-8990. After all, with over 300 dealers around the world, weVe made 6/^3^/^^ DataStar as easy as using DataStar. The world leader in microcomputer word processing. MicroPro International Corporation 1299 4th Street, San Rafael, California 94901 Telex 340388 Dealer/Distributor/O.E.M. inquiries invited. ^Trademark of Digital Research Corporation Prices and specifications subject to change without notice. Listing 3: A hexadecimal object dump of the video-terminal- control routine. C CRTBO o:50oooooc:540ooFA 03002400C3E90528 10004000:51FF8721FF7F2336207DFECFC246007C:l.3 10005000FE87C2460021000022D38722E28722ri8F:l. 100060008722riA8722DC8722DE8722E087210080!=;0 1000700022DA8721808722E6873E00:52D287:52ri!=i7A 100080008732E48732E5873E7Bri3013E27ri30:l.3EAA iooo9ooo3Fri:56i:5EooD:55i:5E4Fri:5503E58D:5!=;o:5EE4 1000A00089D350:5E59ri:550:5E80D:55i:5E00ri:550:5EA9 1000B00000ri350:5EE0ri:^!^>i:5E23D35:I.CD6704DB0:l.4 2 1000C000E602C4D200riB51E620C4A704CDA004C3iri 1000ri000BE00CDD900CriE100C9DB00E67F32ES8767 1000E000C93AE487E6FFCAEri00Cri0B0:I.C93AES87BE 1000F000E660CAF900CD4103C93AE587E6:l.0C205BA 1001000001Cri2301C921E4873A0:I.C93E0032E487CD 100110003AE587E60F0721C104:l.:l.00005F:l.95E234D 1001200056EBE93AE!=i87EA0621E104:l.l0000SF:l.984 100130005E2356EBE92AD3877riFE00(:A420ICDFE3D 1001400002C97CFE00CA4C0:I.CDFE02C92:I.800722F;S 10015000ri3873E1832riS87CD3203C92AD3877DFE97 1001600080CA6801Cri:l.003C97CFE07CA720:l.Cri:l.098 1001700003C9Cri3203CriFF03C93AD287FE4FCA8!=iEA 1 001800001 Cri2A03C92AD3877DFE80C2940:l.7CFEJ^B 1001900007CA9ri0:l.3E0032ri287Cril003C93F00320E 1001A000D287Cri3203CriFF03C93Ari287FE00CAB54C 1001B00001Cri2203C92Ari3877riFE00C2C4017CFE83 1001C00000CACD013E4F32ri287CriFE02C92. 1.800741 1001D00022D3873E4F32D2873E1832DS87Cri3203A!^> 1001E000C921000022D3873E0032ri28732riJ^87CD85 1001F0003203C92AD687EB2Ari3871922DE873E87RA 1 20000 B C D 2 AO 2 C El 2 00 2 C 3 1 6 2 C 2 .1. 6 2 :^ E C F B B E 6 10021000B21602CB20022ABE8722E287CD2A04C92B 100220002ADE871130F81922BE87C93EF00619113F 10023000500021008077190J">C2350221000022B329 100240008721008022B68721808722EA873E0032E0 10025000D28732BS8732E487CD3203C92ADA87EBriri 100260002AB3871922E0873EB7BCB27302C:DE402ED 10027000C37F02C27F023ECFBriB27F02CBE4022AFB 10028000B6877BFE00C297027CFE80C2970221804S 100290008722E687C3A10211B0FF2AD6B7:).922E67h 1002A000873EF02AE087777BFE80C2CB027r.FE870CB3203C921B28734(::ri32TiH 1003300003C93E80B3J^13AB287B3!=;03ABS87B3J^0A0 10034000C93AB287FE4FCAS003CB7403CBB103C9!=i9 1003^.0002AD3B77DFEBO(:;A6003(:;D7403(::DB903C95B 100360007CFE07CAAB03CB7403CBB903C9CD7403F8 10037000CBB003C92AB687EB2AB3871922Br87EB97 1003800021 00003AB2876F19?2ri88/:>E87Brri297CA :i003900003CBBC03C3A303C2A3033ECFBBB2A3039B :i003A000CBBC03CBF 10321 ES877EE63F2AB88777B0 :i003B000C921B28734CB3203C93E0032B2872AB335 :1003C0008711S0001922B38721BS8734(::B3203(::934 :1003D0003E0032B287CB3203CBFF03C92AB8871I20 :1003E00030F81922B8872ABA871130F81922BA87EB :i003F000C92ABA877EFEF0C022E287CD2604C92A08 :i0040000B68722E287CB26042AB6877BFE80C2:IEAB :10041000047CFE87C21E042:1008022B687C91IS0A9 :i 0042000001 922B687C92AE28711S0001922BC87B9 : 100430000120202 1000039EB2ABC87F9CI^;;C5C5CS9C :i0044000CSC5CSC5C5CSCSC!=iC5CSCSCSCSCSCSCSSr. :i004!^;000CSC5CSC5C5CJ^CSC5CSCJ^^CSCJ^;CJ=iC5C5CS4C :i0046000CSCSC!^^C!^;EBF9C93E00B3482AB6877BB39B :i0047000447CB3447B2F6F7r;2F67231.U.:F8719l.i(::4 : 1004800000801 97BB34S7CB3452100807BB3467CF7 :i0049000B34621CF877BB3477CB3473E84D348r,9F9 :1004A000BB61E607C8CBA904C9BB60EEC021E90421 tl004E{0001100005F19DB01E601CAB5047Ei:i300C953 :i004C000C9C0043501SB017901A9012B02C004C038 :1004B00004E101C0045C02F301C004C004C004C0.I4 :i004E00004FB02EF02F202C0041B3 13233343^3 612 :i004F0000009!^)1574S52!=;4S9000041S344464748SA :100S00000000SA5843S6424E200000002F2E2(.:4B1A : 100J^1000000B7B273B4C4B4A000AJ^CSBS04F49J^5 1,2 :100520007FSC3B2B30393837081B2140232425SE60 :100S30000009S1S74SS2S4S9000041^>3444A4748:I9 :i00S400000005AS843SA424E200000003F3E3C4BAA ::L00S5000000B7D223A4C4B4A000A7CSi:i504F49'5SB4 :100S60007F7E2BSC29282A26081B00000000000043 1 1005700000091117051214(9000001 130406070Bri9 I1005B00000001A180306020E200000000000000BF3 :100S9000000B0000000C0B0A000A1C1B100F0915AF :1005A0007F1C0000000000000800000000000000A8 :i005B000000000000000000000000000000000003r< :i005C00000000000000000000000000000000uuu::>H : lOOSBOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOl B :i00SE0000000000000000000003E40B3013EFBB3AB :i005F000013E27B301F331FF87CBA30A3E3FCB89CE :i00600000ACD7706EA7FFE4CCA2306FE44CC360AAE :10061000FE46CCF306FE4BCC1007FE47C2F605CBD4 :i00620006B06E9CB6B06CB!=iF063E2BCBB906CB:OJ=i97 1 1 00 A 3 000 06 7 7 2 3C 3 26 06C D6 BO 6 F B C 06 B O 6 E & 7 D E 6 7 6 :i00640000FC24706Cri5F063E20Cria9067EC,DE6066y :i00650007CBACA590623C33E067riBBC25506C9Ci:i26 :i0066000A3067t:CDE6067DCDE606C9CDA306CDtif;95 :i00670000667CBB5066FC9BB01E602CA7706BB0047 :i006BOOOFElBCAF605Ci:)B906C9F5riB01E602(:;A9B4C :1006900006DB00FE1BCAF605BB01E601CA9806F17F :i006A000B300C93E0BCB89063E0ACB8906C9CB7756 :i006B00006FE30BAF60J^FE3AB8FE41BAF60J^FE47r.8 :i006C000B2F60J^C609C9E60FC630FE3ABAB106C62B tl006D00007CBB906C9CDAE060FOFOFOFE6F047CB47 :i006E000AE06E60F80C9F!=i0F0F0F0FCBC606FlCB90 :i006F000C606C9CB6B06EBCB6B06EB13CBA306CBBB :10070000BJ^064770237CBAC203077BBBC20307C96S : 100710001 603CB6B06E51SC21207E1C103B11A77A6 :0B07200013237AB8C21E077BB9C21E07C999 toooooooooo iflAaft-flflA^^^A^h^lftfti iftte.^Ate^^ft^k^Mte.^Ate.^fite^«iAte lAlM ^^mt iABft^fltei OHIO SCIENTIFIC USERS uo SOFTWARE - GAME AND UTILITY PROGRAMS FOR AS LOW AS $1.00. ALL WITH LISTINGS AND COMPLETE DOCUMENTATION. KITS - UPDATE YOUR COMPUTER TO PLAY MUSIC, INCREASE OPERATING SPEED, HIGH RESOLUTION GRAPHICS AND MUCH MORE, KITS INCLUDE PARTS AND COMPLETE ASSEMBLY INSTRUCTIONS. LOW AS $3.00. OUR $1.00 CATALOG INCLUDES OSl PROGRAMMING TIPS PLUS DESCRIPTIONS OF AVAILABLE PROGRAMS AND KITS. MIITENDORF ENGINEERING 905 VILLA NUEVA DR. LITCHFIELD PARK,AZ 85340 ion mw^^m^ mw^^m^^m^ ■■•i ■■••• ^m^^^mm ^•^ 154 September 1980 © BYTE Publications Inc Circle 96 on inquiry card. CENTRONICS MODa 737: GiveHbur Business Ihe Advonloge Twx "uj-2:4-t'S0? CERTROniCS data corncniier cop THE CK1«XR01«ICS MOOEXl- 737 [ if lei oxrtoriic:!Bi Centronics' new Model 737 means you get more than ever from a printer. Outstanding print quality. Fast, quiet operation. Ready to handle text processing, word processing, or electronic mail in addition to reg- ular small business requirements. And it meets every business' prime requirement: low cost. Outstanding Print Quality Model 737 is the first small business printer to offer correspondence quality printing. Characters with true descenders as well as underlining. Proportional spacing, the ability to justify right margins and serif typeface makes the 737 ideal for text processing appli- cations. Standard business data processing spacing makes it available for applications ranging from let- ters to aged accounts receivable reports. The steel platen assures crisp, clean print impression. Unexpected Features Leave it to Centronics to have some surprises in the new Model 737. You get the ability to print subscripts and superscripts (particularly important for chemical or mathematical applications). The field proven 700 Series printhead technology and fewer moving parts mean reliability that you wouldn't expect in a com- pact, low-cost printer. And the 737 is quiet. An optional acoustic cover makes it ideal for office environments. Circle 97 on inquiry card. Pick Your Paper Run letterhead paper for correspondence, roll paper for general information, or fan-fold paper for standard data processing (payroll, billing, inventory, etc.). You can, with the 3-way paper handling ability of the Model 737. The Printer of the Future . . . Ibday Never before has one printer offered such high quality, reliability, and applications flexibility at such low cost. (If you don't need the correspondence qual- ity of the 737, our Model 730 delivers 100 c.p.s. at even greater savings.) Why Wait? The new Model 737 is now available for delivery. For more information: call (603) 883-0111, Centronics Data Computer Corporation, Hudson, New Hampshire 03051, or any of our 15 U.S.A. or 9 international sales offices. All Centronics products are supported by the largest woridwide service network of any independent printer company. Always use genuine Centronics ribbons and accessories. nTROniCB^PRinTERB ...the advantage •a'pK' Text continued from page 152: be double sided and include plated- through holes. Since producing this type of printed-circuit board is beyond the capabilities of most amateur builders (including myself), I opted for a single-sided board with additional wire-wrap pins and con- nections to complete the wiring. The wiring diagram of the switch matrix is shown in figure 5, and an illustration of the printed-circuit layout is given in figure 6. A 24-pin wire-wrap socket was mounted at the top of the printed-circuit board and serves as a plug for the interconnecting cable. The cable is a 36-inch long DIP jumper with a 24-pin plug on each end. The Vector board also has a 24-pin wire-wrap socket to mate with the cable. Install and Check Out the Video Circuitry The remaining half of the com- ponents can be installed at this point. Check the video-dot-timing circuitry thoroughly to be sure that the correct frequencies are being generated at particular points in the circuit. After resetting the 8085 microprocessor, make sure that the 8224 is oscillating at 22.68 MHz. Pin 5 of IC15 (the 7474) should show the dot rate of 11.34 MHz as well as pin 2 of IC21 (the 74163) and pin 7 of IC22 (the 74166). You should measure a fre- quency of 1.620 MHz, which is the Text continued on page 160 8279 RL7 RLfi RLb RL4 RI-3 RLi RLo SHIFT 39 38 SHIFT LOCK SHIFT CNTL 37 TO 8085 RESET (PIN 36) ■^^ J J y BACK y^ y^ Ju J , Ju Jh Jh ./; ,/; A. ■^ TT TT ^ ( 9 rr -r A- T7 A^ J rr- TT DELETE TT T7- ^ -7- Ai A. J 1^ TT TT- T7- rr TT TT- -7- A 1^ -r }\. J J J J A _ >0^'^» a ^^%,^ AR ^K ^^f/f^^ „^^ ^^ wwi^^ ^wii^^ ^Ki^^i T^hi^^ ^^wi^^ Apparat, Inc., announces the most powerful Disk Operating System for the TRS-80®. It has been designed for the sophisticated user and professional programmer who demands the ultimate in disk operating systems. NEWDOS/80 is not meant to replace the present version of NEWDOS 2.1 which satisfies most users, but is a carefully planned upward enhance- ment, which significantly extends NEWDOS 2.rs capabilities. This new member to the Apparat NEWDOS' family is upward compatible with present NEWDOS 2.1 and is supplied on Diskette, complete with enhanced NEWDOS + utility programs and documentation. Some of the NEWDOS/80 features are: • New BASIC commands that supports files with variable record lengths up to 4095 Bytes long. • Mix or match disk drives. Supports any track count from 18 to 80. Use 35, 40 or 77 track 5" mini disks drives or 8" disk drives, oranycombination. • A security boot-up for BASIC or machine code application programs. User never sees "DOS READY" or ">READY" and is unable to "BREAK", clear screen, or issue any direct BASIC statement including "LIST". • New editing commands that allow program lines to be deleted from one location and moved to another or to allow the duplication of a program line with the deletion of the original. • Enhanced and improved RENUMBER that allows relocation of subroutines. • Powerful chaining commands. • Print Spooler. • DFG function; simultaneous striking of the D, F and G keys will allow the user to enter a mini-DOS to perform some DOS commands without disturbing the resident program, (e.g. dir while in scripsit.) • Upward compatible with NEWDOS 2.1 and TRSDOS 2.3. • Includes machine language Superzap/80 and all Apparat 2.1 utilities. • Enter debug any time by pressing 123 keys. Also allows disk I/O. • Diskette "Purge" command. • Specifiable system options (limited sysgen type commands). • Increased directory capacity. • Copy by file commands. NEWDOS/80withallofthe NEWDOS + utility programs, many of which have been enhanced, is priced at just $149.00 and is available at most TRS-80 dealers. As with 2.1, NEWDOS/80 relies on the TRSDOS and Disk Basic Reference Manual published by Radio Shack. NEWDOS/80 documentation supports its enhancements and upgrades only. msm master charge] Apparat Inc. filA /MlCROCO/MPUrER TECHNOLOGY INCORPORATED TO PURCHASE NEWDOS/80, COMPLETE AND MAIL TO: Apparat, Inc. Microcomputer Technology, Inc. 4401 S. Tamarac Parkway —OR— 3304 W.MacArthur Blvd. Denver, CO 80237 Santa Ana, CA 92704 303/758-7275 303/741-1778 714/979-9923 D Money Order D Master Charge D Visa . Expiration Date. D Check Card No. _ Colo, residents add 6.5% sales tax. Cal. residents add 6% sales tax. Add $10,00 postageand handling. Please rush NEWDOS/80 @ $149 EACH TO: Name - — Address . City. Phone State _ Zip. BO/1 A Circle 98 for MTI Circle 99 for Apparat BYTE September 1980 157 Circle 100 on inquiry card. •IV PERSONAL ATARI* COMPUTER A Warner Communications ^ %# O^T C IV ^ O Co™a.,0 OTOltlVIO ATARI® aOQTM List $1080 ONLY $849 ATARI® 400^1^1, List $630 OUR PRICE ONLY $499 820 PRINTER, List $599.95 $499 810 DISK DRIVE, List $699.95 $589 HP-85 Call for Price • Extended BASIC Language • Advance Graphics • CRT Built-in Display • Magnetic Tape Cartridge for Storage CALCULATORS BY HEWLETT^ PACKARD HP-41C Calculator, "A System" . . $289.95 HP-32E Scientific w/Statistics . . . $ 53.95 HP-33C Scientific Programmable HP-34C Advanced Scientific . . 99.95 Programmable HP-37E Business Calculator . 123.95 .. 58.95 HP-67 Handheld Fully Advanced Programmable Scientific for Business &■ Engineering . 298.95 . 579.95 HP-97 Desktop w/Bullt-in Printer APPLE II, 16K, List $1195 $ 989 32K, List $1395 $1169 48K 1259 COMMODORE PET Call for Prices Prices do not include shipping by UPS. All prices and offers are subject to change without notice. R ersonai ompciter ystems c s 609 Butternut Street Syracuse, N.Y. 13208 (315) 478-6800 o o * o o o »JS o (iJ ^ &1 Si hi O S 'IS o 1J !iJ 3 bo C c o 158 September 1980 © BYTE Publications Inc CHRISLIN YEARS AHEAD IN MEMORY DESIGN WE'VE DONE IT AGAIN — State of the Art Multibus® Memory Design. First to offer up to 512K on one board, and CHRISLIN again brings pricing sanity to the memory market. Why pay over $2000 for our competitor's 64K x 8 memory board when we will give you the CI-8086 1 28K x 9 memory for just $1500 or better yet, the CI-8086 512K x 9 memory module for $4700. Up to 512Kbytes in a single option slot. Available in 64K, 96K, 128K, 256K, or 51 2K configurations. On board parity generator checker, for both 8 bit or 16 bit systems. Off shelf deliveries. ill I III I II mi mmMm W li&UUli iiti: 8 Wl\ CI-6800-2 — 16KB to 64KB. Plugs directly into Motorola's EXORciserlorll. Hidden refresh up to 1.5 Mhz. Cycle stealing at 2 Mhz. Addressable in 4K increments with respect to VXA or VUA. On board parity. 64K x 9 $995.00. CI-S1D0 ~ 16KB to 64KB. Transparent hidden refresh. No wait states at 4 Mhz. Compatible with Alpha Micro and all Major 8080, 8085 and Z80 Based SI 00 Systems. Expandable to 512K bytes thru Bank Selections. 64K x 8 $750.00. iJllUlfii imiiiiii CI-8080 — 1 6KB to 64KB on a single board. Plugs directly into MDS 800 and SBC 80/1 0. Addressable in 4K increments up to 64K. 16KB $390.00. 64KB $750.00. MiWBiTfiimmim CI-1103 — 1 6KB to 256KB on a single dual height board. Plugs directly into LSI 11/2, H1 1 or LSI 11/23. Addressable in 2K word increments up to 256KB. 8K X 16 $390.00. 32Kx 16 $750.00. 128K X 18 $2880.00. CI-6800 — 16KB to 64KB on a single board. On board hidden refresh. Plugs directly into EXORciserl and compatible with Rockwell's System 65. Addressible in 4K increments up to 64K. 16K x 8 $390.00. 64K X 8 $750.00. Tested and burned in. Full year warranty. DON'T ASK WHY WE CHARGE SO LITTLE ASK WHY THEY CHARGE SO MUCH. Chrislin Industries, Inc. Computer Products Division 31352 Via Colinas • Westlake Village, CA 91362 • 213-991-2254 Multibus is a trademark of the Intel Corp. LSI II is a trademark of Digital Equipment Corp. EXQRciser is a trademarft of Motorola Circle 101 on inquiry card. BYTE September 1980 159 Text continued from page 156: character clock rate, on pins 6 and 8 of IC14 (the 7410), pin 12 of IC21 (the 74163), on pin 9 of IC23 thru IC27 (all five 74175s), pin 1 of IC21 (the 74163), pin 15 of IC22 (the 74166), and pin 30 of IC9 (the 8275). Pin 7 of the 8275 should measure 16,200 Hz, the horizontal line frequency, and pin 8 should be at 60 Hz, the frame fre- quency. Do not proceed until you can measure all of these frequencies cor- rectly. If your display shows something quite distorted, torn, or scrambled, it is probably a problem in the video timing. An incorrect horizontal or vertical sync frequency can greatly disrupt a display. Final Checkout At this point, your terminal should be working. If it is not, double-check the following: • On opening the TRAP switch, does the 8085 microprocessor branch to the monitor program and issue a carriage return, line feed, and question mark from the 8251? • Are all of the frequencies listed above for the video timing correct in your circuit? • Check the output of pin 35 of the 8275. This is the video-suppression (VSP) output which is active high during horizontal and vertical retrace at the top and bottom rows of every character, and in certain other cases involving end-of-row or end-of -series codes. Video sup- pression is also turned on if a direct-memory-access underrun occurs. If video-suppression is pro- ducing a logical 1 and has no ac- tivity on it, a direct-memory- access underrun is most likely your problem. This means that the soft- ware is not reinitializing the 8257 at the end of each video frame. The video-suppression line should show a frequency of 12 kHz on it. Pin 37 of the 8275 (the light-enable output) will have a frequency varying from 28 to 32 Hz. • After the 8085 microprocessor has been reset and before data is sent to the video terminal, IC18 (the 74LS138 peripheral decoder) should be putting out pulses at constant rates. Pins 9, 10, and 15 should show a frequency of about 23 kHz, and pin 11 should show 600 Hz. • The address-enable line on the 8257 (pin 9) should show a fre- quency of 1.5 kHz, and the ad- dress strobe (pin 8) should be 135 kHz. Again, these frequencies should be measured by a counter using a full 1-second gate time, since the duty cycles of pulses of these lines are not constant. This is especially true of the address- strobe output of the 8257. Using a frequency counter and an oscilloscope to check for the correct activity on the various pins of in- tegrated circuits is an effective method of troubleshooting your cir- cuit. It is possible that a single wiring mistake is your only problem. Using an ohmmeter as a continuity tester and checking every connection is often worth the effort. I turn the cir- cuit board over and put the ohm- meter probes on the pins of the in- tegrated circuits themselves. This also serves to check for a bad socket con- nection. Draw over the connecting lines on your progress-checking schematic with a different colored pen as you make each check. Possible Additions Some readers may wish to make further modifications to my design. Here are some possibilities: • Lowercase letters could be added fairly easily if the 7 by 10 format for each character is retained. The + 5 V 2513 character generator is also available with a lowercase set of letters. The second character generator could be added by using the full 7-bit ASCII code in memory. Only six bits are stored in memory in this design. The most significant bit could be used to select which character generator would be enabled. The character- handling routine in the terminal control software would also have to be modified. If a larger format for characters was desired (eg: that used by the Motorola 6571 character generator), the entire dot timing would have to be changed, as well as the initialization of the 8275 in the software. • The 8275 Video Display Controller has provisions for light-pen detec- tion. Very little hardware would be needed to add this feature; only a small switch and a small light- sensor circuit using a phototran- sistor. When the raster sweep reaches the light sensor, it presents a signal to the light pen (LPEN) in- put, and the row and character positions are stored in a pair of registers in the 8275. These registers can be read on command. Modification of the control soft- ware would be necessary to read the registers and act upon their contents. • Character- and field-attribute codes can also be handled by the 8275. Character-attribute codes are used to generate graphics sym- bols without the use of the character generator. These sym- bols can also be programmed to blink or be individually high- lighted. Field attributes are codes that affect the characteristics of a field of characters. These charac- teristics are blink, highlight, reverse video, underline, and two general-purpose outputs that can be user defined. The Intel Peripheral Design Handbook gives details on implementing these features in both hardware and soft- ware. Conclusion This terminal is not a suitable pro- ject for a beginner or for those who are inexperienced in microprocessor hardware. Time and patience will be indispensable in completing this pro- ject. I spent about three months assembling the parts and building the circuit. A month of this time involved debugging both hardware and soft- ware, due to the many changes I made in the original Intel design. I would appreciate hearing from those readers who complete this pro- ject. Descriptions of any modifica- tions made would also be welcome. ■ Portions of this article are copyright by Intel Corporation and are used by permission. A Public Service of This Magazine & The Advertising Council ^Wl Need help? Callus. -I Red Cross coiinlii>g on you. 160 September 1980 © BYTE Publications Inc Discover the most organized (and inexpensive) way to lengineering. To get control of your own Empire, see your quality computer store for quick delivery. Or, contact us for dealer locations or further in- formation. CP/M is a trademark of Digital Research. 950 Dovlen Place - Suite B Carson, California, 90746 (213) 538-4251 / 538-2254 BYTE September 1980 167 AMSAT is continuing to develop software to be used by ground stations in the satellite networks and is seeking support from per- sonal computer users in this software-development effort and in other areas of the rebuilding program. Infor- mation on AMSAT and its programs may be found in Orbit, which is published every two months and re- ceived by all members of the AMSAT group. A year's membership may be ob- tained for $10 from AMSAT, POB 27, Washington DC 20044. The AMSAT space pro- gram is not a complete loss, however. The Phase II OSCAR-8 satellite contin- ues in orbit, and a group of radio amateurs from the University of Surrey in England will launch the scientific-research sateUite UOSAT in late 1981. Carrying a coherent high- frequency beacon, a mag- netometer, and a slow-scan television camera, the ''bird" will provide oppor- tunity for ham radio and personal-computer users to gain experience in tracking satellites and monitoring telemetry. Xftandom Bits: It is in- teresting to note that IBM, via its Science Research Associates subsidiary, is marketing the Atari per- sonal computer to educa- tional users. In fact, IBM is offering a special sale. If you buy one Atari Model 800 system, they will give you an Atari Model 400 system free....Avalon-Hill, well known in the war gam- ing field for its historical simulation board games, has introduced a line of microcomputer-assisted games for the TRS-80, Apple II, and Commodore PET.... The sales of the Texas Instruments (TI) Model 99/4 personal com- puter have been so disap- pointing that in the Los Angeles area TI has started offering $100 worth of free software plus a $100 cash rebate .... Apple Computer Company has shifted its Apple II production from Silicon Valley to Carrolton, Texas, a mere 30 miles away from the new 100,000-square-foot plant Tandy has built to make TRS-80S....A record 82,000 people attended the Na- tional Computer Con- ference (NCC), in Anaheim, California, this past May. The NCC is the largest computer show in the world. When it was held in Anaheim two years ago, 55,000 attended, which set the record just smashed.... Data General has begun selling its business-oriented micro- computer systems through independent computer stores nationwide.... Fujitsu America Inc, Lake Bluff, Il- linois, has announced a plug-in ''Bubble Memory Cassette." It provides a portable, detachable, read/write block of 64 K bits. Fujitsu has also in- troduced a new fully- formed-character printer with speeds up to 80 cps (characters per second), nearly twice the speed of conventional daisy-wheel machines. The printer is currently offered as a $4500 option to a word-processor system.... Texas Instruments is now making the voice- synthesizer components used in the Speak & Spell and talking Language Translator available separately at $13 in OEM (original equipment manufacturer) quantity.... Shugart Technology, BASF, Control Data, and Erwin Interna- tional, Ann Arbor, Michigan, are all expected to have 5-inch Winchester hard-disk drives available by the year's end.... Com- modore will be the first US manufacturer to use the new low-cost Shugart/Mat- sushita 5-inch floppy-disk drive.... Zilog and Mostek have both announced that 6 MHz versions of the Z80 microprocessor will be available in production quantities next year. X^andom Rumors: It is rumored that Commodore will soon introduce two low- end personal-computer systems. One will be a black-and-white unit for under $500 and the other a color unit for under $800.... Apple may be working on a low-end con- sumer computer that will compete with Mattel's In- tellivision.... Personal Soft- ware, Sunnyvale, Califor- nia, the folks who brought out Microchess and VisiCalc (probably the two largest-selling personal- computer software pack- ages to date) are rumored about to release VisiText, a superpowerful text editor with features never before seen.... NEC (Nippon Elec- tric Corporation) is rumored to be investigating selling its Model PC -8000 microcomputer here in the US, after selling it in Japan for some time. I BM Demonstrates Continuous Voice Recognition: IBM research scientists, at the Thomas J Watson Research Center in Yorktown Heights, New York, have demonstrated that continuous speech can be recognized by a com- puter with an accuracy of 91%. In continuous speech there are no pauses be- tween words. In the IBM experiment, the computer transcribed normal-speed speech into printed form. The program took 100 minutes to display or type a transcript of a 30-second sentence. In other words, it has a 200:1 response-time ratio. The experiment proves that continuous speech recognition by com- puters is possible. Uc ^CSD Pascal Controversy Continues: Several former University of California, San Diego (UCSD) Pascal hcensees are threatening to file suit against UCSD and its new exclusive licensee, SofTech Microsystems. The licensees charge that UCSD violated the "fair use doctrine" in arbitrarily cancelling their licenses only a short time before the software would have entered the public domain. About thirty organiza- tions, mostly computer hob- byist clubs, paid $200 to $300 for a UCSD Pascal license that permitted distribution of the software to their members and, after two years, would have placed no restrictions on copying the software. These licensees are also upset over what they charge to be software developed with public funds now being sold by a private organization. SofTech counters this charge by asserting that it is merely an agent of the university and that it in- tends to spend as much money on developing UCSD Pascal as did the university. One UCSD Pascal pur- chaser had an un- cancellable license: Apple Computer Company. Its license, however, is restricted exclusively to use of the software on Apple Computer systems. X erminal Gets Voice Input: Heuristics Inc of Sunnyvale, California, has introduced a speech- recognition system which works with a Lear Seigler ADM-3A video terminal. The unit, called VOCON 5000, recognizes 64 words or phrases that can control a program being run on the computer. A 99% recogni- tion rate is claimed for the unit, which sells for $2000. MAIL: I receive a large number of letters each month as a result of this column. If you wish a response, please in- clude a stamped, self- addressed envelope. Sol Libes Amateur Computer Group of New Jersey (ACG-NJ) 1776 Raritan Rd Scotch Plains NJ 07076 1t83-308 p.— Trouble- An Extraordinary Utter to introduce you to the benefits of Membership in ELECTRONICS BOOK CLUB of these 24 unique ^ electronics books ^ (values ton 05'^) for only with a Trial Membership in the Book Club that guarantees to save you 25% to 75% on a wide selection of electronics books fBe^^^' ' I 1 136-504 p.— Practical Electronics Math ($15.95) 1060-308 p.— 303 Dynamic Electronic Circuits ($9,95) 1101-546 p.— How To Design & Build Your Own Custom TV Games ($14.95) 1064-336 p.— HOW To Design, Build and Test Complete Speaker Systems ($10.95) 1 1066-&68 p.-The Illustrated Dictionary ^ of Electronics ($19.95) 1077-304 p.— Handbook of Remote Control & Automa- tion Techniques ($12.95) ^4 'E'Crjs'' To Everything Electronic For The Home ($9.95) 1199-476 p.— Ttie M aster IC Cookbook ($15.9 ,|i.^Bulld-lt Book of Digital p Timepieces ($9.95) 8224-672 p.— The Complete Handbook of Radio Receiver and The Complete Handbook of Radio Transmitters ($19.95) fi).322 p.— Master Tube bbstltution Handbook ($8.95) fi/lD/0 1205-350 p.— PASCAL ($15.95) S»M"__i_SSa_ 1222-266 p.~Advanced Radio Control, including Rockets & Robots— 2nd Edition ($12.95) r^ iiisrs dictTonarv of I' C0L08.TI ., MCROCOMPUirEP ^ ;],; TERMINOLOGV^ 1133-280 p.— The Active Filter ^ Handbook ($9.95) 1119-532 p.— Color TV Trouble Factbook— Problems & Solutions-4th Edition ($12.95) gccording ^^2^ 1123-210 p.— The Laser Experimenter's Handbook ($9.95) 1184^16p.-TheMaMerGiiideTo I io59-*48 p.-Tne Complete Handbook Electronic Circuits ($1 9.95) I ^ Magnetic Recording ($1 5.95) \ Facts About Club Membership • The 6 introductor^^books of your choice carr^ publisher's retail prices of up to $105.70. They are yours for only $2.95 for all 6 (plus postage/handling) with your Trial Membership. • You will receive the Club News.describing the current Selec- tions, Alternates, and other books, every 4 weeks (13x a year). • If you want the Selection, do nothing, it will be sent to you automatically. If you do not wish to receive the Selection, or if you want to order one of the manyAlternates offered, you simply give instructions on the reply form (and in the envelope) provided, and return it to us by the date specified. This date allows you at least 10 days in which to return the form. If. becauseof late mail delivery, you do not have 10 days to make a decision and so receive an unwanted Selection, you may return it at Club ex- pense. • To complete your Trial Membership, you need buy only four additional monthly Selections or Alternates during the next, 12 months. You may cancel your-Membership any time after you purchase these four books. • All books— including the Introductory Offer— are fully return able after 10 days if you're not completely satisfied. • All books are offered at low Member prices, plus a smal postage and handling charge. • Continuing Bonus. If you continue after this Trial Membership, you will earn a Dividend Certificate forevery bookyou purchase. Three Certificates plus payment of the nominal sum of $1.99 will enfitleyou to a valuableBookDividend of yourchoicewhichyou may choose from a list provided Members. May we send you yourchoice of 6 of these practical time-and-money-saving books as part of an un- usual offer of a Trial Membership in Electronics Book Club? Here are quality hardbound volumes, each espe- cially designed to help you ijicrease your know-how, earning power, and enjoyment of electronics. What- ever your interest in electronics, you'll find Elec- tronics Book Club offers practical, quality books that you can put to immediate use and benefit. This extraordinary offer is intended to prove to you throuj»h your own experience, that these very real advantages can be yours... ihai it is possible to keep up with the literature published in your areas of interest, and to save substantially while so doing. As part of your Trial Membership, you need purchase as few as four books during the coming 12 months. You would probably buy at least this many anyway, wnth- out the substantial savings offered through Club Membership. To start your Membership on these attractive terms, simply fill out and mail the coupon today. Yyu will receive the 6 books of your choice for l(J-day inspection. YOU NEED SEND NO MONEY. If you're not delighted, return the books within 10 days and \our Trial Membership will be cancelled wnthoLil cost or obligation. ELECTRONICS BOOK CLUB Blue Ridge Summit, Pa. 17214 Please open my Trial Membership in ELECTRONICS BOOK CLUB and send me the 6 books circled below. I understand the cost of the books I have selected is only $2.95 for all 6, plus a small shipping charge.lf not delighted, I may return the books within 10 days and owe nothing, and have my Trial Membership cancelled. I agree to purchase at least four addi- tional books during the next 12 months after which I may cancel my membership at any time. 800 801 804 971 985 1000 1050 1053 10551066 1077 1088 1101 1123 1136 1141 1169 1183 1184 1199 1203 1205 1225 1241 Name_ . Phone _ Address. City State. -Zip. ELECTRONICS BOOK CLUB, Blue Ridge Summit. Pa. 17214 ■ (Valid for new Members only. Foreign and Canada add 15°-6,) BY-980 Circle 105 on inquiry card. BYTE September 1980 169 LECTURE PROGRAM A schedule of free lectures is available to all visitors. Lectures run about 50 minutes each, including, in most cases, some time for questions from the floor. Some topics are given twice, and, in some cases, topics of related interest are given on the same day for the visitor's convenience. (Program is subject to change without notice, but lectures will be posted daily in the show lobby.) THURSDAY, OCTOBER 30 Noon Introduction to Small Systems for Business, Stan Veit, Associated Computer Industries Noon Mailing Lists: Several Directions, Dr. Norman I. Agin, Mathtech, Inc. 1 p.m. Selecting a Small Computer for Business, David Benevy, Computer Mart of New Jersey 1 p.m. Evaluating and Improving Your Computer's Performance, Philip Grossman, Raytheon Co. 2 p.m. Law Office Systems Aspects of Word Processing, Bernard Sternin 2 p.m. Future Smart Machines: 2000 A.D. and Beyond, Dr. Earl Joseph, Sperry Univac 3 p.m. Computer Contracts— Facing the Issues, Alan C. Verbit, Verbit and Company 3 p.m. Accounts Receivable/Accounts Payable/ General Ledger 4 p.m. Using FORTRAN on a Microcomputer, Richard A. Zeitlin 4 p.m. Investment Analysis of Stocks and Commodities on a Microcomputer, Fred Cohen, Shearson Loeb Rhoades, Inc. FRIDAY, OCTOBER 31 Noon Introduction to Small Systems for Business, Stan Veit, Associated Computer Industries Noon BASIC Programming, Michael Mulcahey, Worcester Stage College 1 p.m. Selecting a Small Computer for Business, David Benevy, Computer Mart of New Jersey 1 p.m. Videoprints: Full-Color, Low-Cost, Hard- Copy Computer Graphics, Warren Sullivan, Image Resource Corp. 2 p.m. Mailing Lists: Several Directions, Dr. Norman I. Agin, Mathtech, Inc. 2 p.m. Business Applications Software Development via Data Base Management, Dr. Andrew Whinston, Micro Data Base Systems 3 p.m. Application of PASCAL to Small Systems for Business, Panel, Stan Veit, Moderator, Associated Computer Systems . 4th Hnnual national Small A NEW WORLD OF SMALL COMPUTERS IS AT YOUR FINGERTIPS THIS FALL When we say "fingertips" we mean just that: a hands-on-inspection opportunity for you to try the small computers and systems that will write the history of microprocessing in the 1980's. Manufacturers will fill over 30,000 square feet with computers, soft- ware and peripherals. Amazing strides in technology are reflected in exhibits and lecture series. New hardware and software for business, education, the sciences and professions, graphics and personal use are being gathered for the largest and most beautifully presented National Small Computer Show ever produced. As always, the show contains attractions for the seasoned compu- ter professional, as well as those who wish an introduction to the exciting world of small computers for business, professional or personal use. In just a short time, you can discuss your interest with many industry leaders, vendors, technologists, and our expert lecturers. Registration fee is only $10 per day, and all registrants have free access to the hourly lectures. New York Coliseum, October 30 to Nov. 1 , 1 960 4th ANNUAL NATIONAL SMALL COMPUTER SHOW no Charlotte Place, Englewood Cliffs, NJ 07632 (201) 569-8542 3 p.m. Investment Analysis of Stocks and Commodities on a Microcomputer, Fred Cohen, Shearson Loeb Rhoades, Inc. 4 p.m. Advantages of Distributed Processing and Multi-Processing, John Steefel, Q1 Corp. 4 p.m. To be assigned. SATURDAY, NOVEMBER 1 Noon Educational Software: The Good, the Bad, the Ugly. Jo Ann Comito, S.U.N.Y at Stony Brook Noon Introduction to Personal Computing, RCA— Solid State 1 p.m. Computer-Assisted Mathematics Courses, Dr. Frank Scaizo, Queensborough Community College 1 p.m. Artificial Intelligence Update, Prof. Peter Kugel, Boston College 2 p.m. Compiling and Retrieving Personal Medical Data, Dr. Derek Enlander, St. Luke's Hospital 2 p.m. The Present State of CP/M Compatible Software, Tony Gold, Lifeboat Associates 3 p.m. High Volume Date Handling: An Introduction to File Processing, Prof. Peter Kugel, Boston College 3 p.m. Connecting the Computer to the Outside World, Prof. James Gips, Boston College 4 p.m. Educational Applications in the Home, David Ahi, "Creative Computing Magazine" 4 p.m. Household Applications— Some New, Dr. Dennis J. McGuire SPECIAL SESSION: EXECUTIVE EDUCATION CONFERENCE FOR BUSY PEOPLE This year, NSCS will present a special five-hour conference formulated as an intensive fast education for administrators and executives. The aim is to show the conferee how to cope with computers in business. No prior knowledge of computers is needed. The session will proceed on a step-by-step basis, covering computers, computer jargon, software, systems, and peripherals. It will indicate how to assess computer requirements, how to talk to vendors, and how to make a system work efficiently, after you've bought it wisely. An executive education session will be given daily for four days, Oct. 29 through Nov. 1, in the New York Coliseum. Each session is limited in attendance, and reservation must be made. Registration is on a first-come, first-served basis. Fee is $200, and includes three-day admission to the National Small Computer Show, coffee break, and workbook materials. Please write or call the show office for session outline and registration form. (Do not use registration form in this ad). Seminar instructor is Barbara Schwartz, author and seminar leader for private industry. Computer Show Circle 106 on inquiry card. -REGISTRATION FOR AMERICA'S BIGGEST SMALL COMPUTER SHOW Please register me for the 4th Annual National Small Computer Show, Oct. 30 - Nov. 1, 1980 New York Coliseum. NAME COMPANY (If Any)_ ADDRESS BUSlNESSTITLE(lf Any)_ TELEPHONE ZIP Your company's primary business. Check one. 1 D Accounting firm 2 D Advertising Marketing 3 D Banking/Insurance/ Real Estale/CreditySecurities 4 D Communications 5 D Computer Consultant 6 D Computer Dealer'DisI 7 D Construction/Architecture D Engineering D Entertainment. News D Government/Military D Hospital D Hotel D Industrial Design D Law Office D Management Consultant 18 D Personnel Agency 19 D Professional Services 20 D Research/Development 21 D Transportation (All) 22 D Umny 23 D Wholesale/Retail Sales 24 D Omer (Please Spec;fy) 8 U Education 1 7 U Manufacturing Check your primary job function. 1 D Account Executive 9 D Designer (All) 17 D Salesperson (All) 2 D Administrator 10 D DP WP Manager. Operator 18 D Scientist 3 D Bookkeeper 1 \ a Doctor 19 D Skilled Laborer 4 D Chemisl/Pharm 12 D Engineer (All) 20 D Student 5 D Consultant 13 D Lawyer 21 D Teacher 6 D Corporate Officer 14 D Office Manager 22 D Technician r U CPA 15 D Programmer 23 D Other (Please Specify) 8 D Creative Arts (All) t6 D Purchasing Your primary interest in computers (check only c D ONE DAY $10 D TWO DAYS $20 a THREE DAYS $30 Mail with payment of $10 for eacfi day you wish to attend, Use one form per person. Re- gistration badge will be sent by mail in early October. Check or money order only. Mail prior to October 10, 1980. Foreign orders: October 1, 1980. National Small Computer Show 110 Charlotte Place Englewood Cliffs, NJ 07632 201-569-8542 Ask BYTE Conducted by Steve Ciarcia Levels to Bits Dear Steve, 1 have been shopping around for the analog-to- digital (A/D) converter in- tegrated circuit that you used in your wood-stove in- terface (see "A Computer- Controlled Wood Stove/' February 1980 BYTE, page 32), but it does not seem to be readily available. C W Vuaun / try to avoid specifying components that are not commonly available. While I obtain parts through in- dustrial distributors rather than surplus outlets, I check the latter often to see what is available. In the case of the ADC0808, the time-lag is greater than I expected. However, in the meantime there is a sixte en-channel version, the ADC0816CCN, which is the same in every respect (except that it has twice as many channels). It is available from Digi-Key Corporation, FOB 677, Thief River Falls MN 56701. Their toll-free phone is (800) 346-5144. Call or write them for the current price. Steve More Power Dear Steve, I noticed your comment on UPSs (uninterruptible power supplies) in the June 1980 BYTE (see "Ask BYTE," page 86), and thought I would mention that they are commercially available in sizes small enough to be useful to TWICE THE BYTE! 8" DISK CONTROLLER NOW— DOUBLE SIDED OPTION! • DOUBLES APPLE )[ STORAGE • APPLE DOS COMPATIBLE • SHUGART 800 OR 850 COMPATIBLE • IBM 3740 DATA ENTRY CAPABILITY • CP/M, UCSD PASCAL CAPABILITY Available at your local APPLE Dealer: $400. ^"^ \ S( >SVA> 11 SORRENTO VALLEY ASSOCIATES 722 SORRENTO VALLEY RD. SAN DIEGO, CA 92121 personal-computer users (see the Hardside catalog, page 34). I do not know who the actual manufacturer is, but I would like to know more about these items. The devices I am concerned with have specifications that ac- commodate 60 and 120 Hz power, with and without surge protection, and supply 150 or 200 W. The trade name is "Mayday." R M Sanford Thank you for pointing out the Mayday UPS. It is manufactured by Sun- Technology Inc, which is located in New Durham, New Hampshire. The May- day UPS is available from Hardside, 6 South St, Milford NH 03055, (800) 258-1790. According to the Hardside catalog, prices begin at SI6(S .... Steve A Hot Tip Dear Steve, The solid-state sensor you described for your wood stove (see "A Computer- Controlled Wood Stove," February 1980 BTYE, page 50) is very interesting. I have constructed the circuit, but I am having trouble calibrating the device for a range of -18 to -i-100°C. Ron Goodmaster The circuit you refer to can be calibrated in a number of ways. There is an offset and gain adjustment included for this purpose. In normal practice, say for a range of 0° C to 100° C, we would adjust for offset so that the output was V with the temperature probe in an ice bath and ad- just the gain so that the out- put is 1.00 V when it is placed in boiling water. To have it actually read —18° as —0.18 V you will have to modify the circuit slightly. Presently the 50 k offset- adjustment potentiometer is connected between -\-12 V and ground. By connecting it instead between -\- 12 V and —12 V you can impress a negative current flow into IC2 such that it has a negative offset. The gain of the circuit will now have to be adjusted for a 118-degree span instead of 100 degrees. The trick is that to accurate- ly calibrate the unit you should have a —18° C stan- dard when you set the low end. Substituting a voltage source for the LM334 will only give you a relative calibration, but it may be all you need.... Ste\e Remote Control at Home Dear Steve, The other day I was thumbing through a BYTE magazine and I came across the article you wrote about using the TRS-80 and the BSR X-10 home-control system. (See "Computerize a Home," January 1980 BYTE, page 28.) I had been work- ing on the same project in my spare time, and I had been using opto-isolators for interfacing; however, your method is well above the idea that I was attempting. Your article was very infor- mative and the accompany- ing software was excellent. I have since looked up your articles in other BYTEs, and I must say that you never fail to come up with in- teresting and practical pieces. I have decided to use your method, and I will shortly be purchasing a "Busy Box" from MicroMint in Woodmere, New York. Whenever I have my TRS-80 up and running, the Sears home-control-unit operation is either marginal or nonexistent. The minute I turn the TRS-80 off, the home-control unit works fine. I assume that the prob- 172 September 1980 © BYTE Publications Inc Circle 107 on inquiry card. AUTHORIZED TRS-80® ALER A301 10% DISCOUNT Off List 26-4002 64K1 Drive $3499.00 COMPUTER SPECIALISTS 26-1056 16K Level II System with Keypad .$688.00 26-1145 RS-232 Board 84.00 26-1140 "O" K Interface 249.00 26-1 141 "16" K Interface. 365.00 26-1 1 42 "32" K Interface . 476.00 26-1 160 Mini Disk - Drive O 424.00 26-1161 Mini Disk • Additional 424.00 26-1154 Lineprinter II 720.00 26-1156 Lineprinter III 1799.00 , 26-1180 Voice Synthesiser 339.00 26-1181 VOXBOX 145.00 26-1104 Factory Upper/Lower Case Modifoction Installed 70.00 26-1506 Scripsit • Tope 60.00 26-1563 Scripsit - Disk 85.00 15% DISCOUNT Off List 26-1054 4K Level II $552.00 CEnTROniCB Fast TOO GPS Centronics 730 Printer - $675.00 Text Quality Centronics 737 Printer - $850.00 ALL OTHER R.S. SOFTWARE FURNITURE. STANDS. CABLES AND ACCESSORIES DEDUCT 10% FROM CATALOG PRICE Model II Cobol Compiler $360.00 Cobol Run Time Package $36.00 Novation Cat Modem. .$149.00 CCA Data Management System 72.00 Adventure Games Games 1-9 each 14.00 Model I Basic Compiler $180.00 Model II Basic Compiler 360.00 BASF 10-5 'A Diskettes $45.00 10-8" Diskettes 47.00 H Acorn Software Products, Inc. GAMES: Alien Invasion $9.00 Stock Market 9.00 Star Trek 9.00 Block 'Em 9.00 Ting-Tong 9.00 UTILITIES: System Savers 14.00 EDUCATION: Language Teacher 18.00 1-800-841-0860 ToII Free Order Entry I^JCRQ l^flUflGEiriEMT SVSTEI^S, iMC. No Taxes on Out Of State Shipments Immediate Shipment From Stock. DOWNTOWN PLAZA SHOPPINGCENTER 115CSEC0NDAVE.S.W. CAIRO, GE0RG1A31728 (912) 377-7120 Ga. Phone No. •TRS-80 U a registered trademark of the Tandy Corp. Full Factory Warranty on All Items Sold. Largest Inventory In the S.E. U.S.A. Circle 108 on inquiry card. BYTE September 1980 173 SSG Writing and Mailing Systems. Vtezesfti^ Take Letteright for quick document preparation and edit plus NAD Name And Address for extensive mailing list capabilities. Put them together and you've got a flexible, powerful solution to big and small correspon- dence problems. With Letteright you create and edit your document right on the screen. It's much easier to use than a typewriter. The letters are always perfect, and revisions are a snap. Letteright's "wild card" slots let you create standard letters and forms, then insert informa- tion selected from your mailing list to address and "personalize" the letter. The NAD system will store lots of names and addresses, with identifying information you create. You then print lists, labels, or envelopes of virtually any group you want from the list, or the whole list. jg^ t 1 This pair should be working for every ^ s.uc.ureu sy..n.sooup microcomputer owner. tetteright and NAD ore pad of a full line of working software solutions from Structured Systems Group, all ready to run on any CP/M® microcomputer system. CP/M is a registered trademark of Digital Research. Structured Systems 5204 Claremont Oakland, Ca 94618 (415) 547-1567 Circle 109 on inquiry card. lem is RFI (radio-frequency interference), but I am not quite sure how to cope with the problem. I know the TRS-80 is a great noise generator, but I know little of how to deal with the problem. If you can give me any help along these lines, I would appreciate it very much. Thanks. Robert G Romppel Radio- f requeue]/ in- terference (RFI) is so per- vasive among personal com- puters and consumer elec- tronic gadgets that the Federal Communications Commission (FCC) has ex- tended the long arm of the law. See Terry Mahn's ar- ticle "FCC Regulation of Personal Computers and Home Computing Devices" on page 180 in this issue. As for now, there are various alternatives open to you. First, try plugging the B5R unit into a different wall socket than the TR5-80. The range of the Busy Box is 30 feet, so it doesn't have to be right next to the computer anyway. (Avoid extra long extension cords and use a plug strip for the computer and peripherals.) The noise from the computer is being radiated into the power line; therefore you want to put as much electrical distance be- tween the TR5-80 and the X-10 as possible. While there may be five wall outlets in an average room, they are rarely all on the same circuit breaker. For the noise to reach an appliance plugged into another circuit loop, it must first travel back to the breaker box. This is a lot of wire and the resulting induc- tance will diminish some of the interference. If that doesn't work, next try to kill the noise at the source (the computer) by placing capacitors at the outlet. I suggest using three 0. 1 jiF 600 V disc ceramic capacitors, one from each side of the AC line con- nected to a good earth ground and another across the line. Ordinarily, you would also connect the com- puter chassis to ground but this is not advisable on the TR5-80. To really eliminate line noise, you need a combina- tion of inductance and capacitance. Rather than trying to wind your own coils, it is better for you to buy a commercial noise sup- pressor. You want one that covers at least a range of 100 kHz to about 200 MHz. They are about $20 and up. One company that lists a few in its catalog is: Hardside, 6 South St, Milford NH 03055, (800)258-1790. If none of this works, then encase the entire thing in copper screening and run it on a battery! ...Steve Remote Control on the Farm Dear Steve, I am a graduate business student at Colorado State University working with David R Miller, Sun Up Angus Farms, Smithville, Missouri, in establishing an in-house computer system for his ranch. This will also be the topic of my thesis. Presently the main areas that we see a need for a computer are: 1) cattle inventory — pedigree, calving dates, breeding dates, calf weights; 2) customer service — date, identification, and price of animals purchased, commercial or registered breeder, size of herd, etc; 3) accounting system — basically following the Internal Revenue's 1040 form with some variations; 4) various other programs for feed-ration analysis, investment analysis, profitability, etc. I am interested in any ex- isting computer programs or any information on the hardware available. Also, if you have any information about the cost, complexity. ^^^"v^S-^ni- with RAM XX W RAM XX, our latest static memory board, satisfies discriminating users of ALL S-100 machines while allowing you to keep pace with the state of the art. It's compatible with S-100 systems (Altair. IMSAI, etc.); bank select systems (Cromemco, Alpha Micro, North Star, etc.); and IEEE compatible extended addressing systems. RAM XX boards are addressable on 4K boundaries and also have the capability to block out 4K windows. Don't throw away your memory boards when you upgrade - with RAM XX, simply change a few dipswitch settings and you're on-line with some of the best memory in the business. b« As with all our memory products, you derive the benefits of 4/5 MHz operation, fully static design to eliminate dynamic timing problems, IEEE spec compatibility, low power, extensive bypassing, and careful thermal design. In addition, boards qualified under our Certified System Component high-reliability program run at 8 MHz typical and are guaranteed to run with 6 MHz Z80A CPUs; 32K CSC boards draw less than 1.5A guaranteed, with typical standby current of less than 1A. If you're looking for specs — if you're looking for performance — if you're looking for exceptional value and insurance against obsolescence , look no further than the RAM series from CompuPro. unkit ass 16K RAMXX-16 $349 $419 $519 24KRAMXX-24 $479 $539 $649 32K RAM XX-32 $649 $729 $849 OTHER S-100 MEMORY (includes IEE compatible extended addressing.) 8K RAM IIA $169 $189 $239 16K RAM XIV $299 $349 $429 SBC/BLC MEMORY 32K RAM XI n/a n/a $1050 COMPUPRO S-100 MOTHERBOARDS: DESIGNED FOR THE FUTURE, AVAILABLE NOW Specifically designed to handle the new generation of 5 to 10 MHz CPUs coming on line (as well as present day 2 and 4 MHz systems), these advanced motherboards feature Faraday shielding between all bus signal lines to minimize crosstalk, active termination that splits the termination load between each end of every bus line, and mechanical compatibility with Godbout, Vector, Imsai, TBI, and similar enclosures. Available in "unkit" form (edge connectors and termination resistors pre-soldered in place for easy assembly), or fully assembled and ready to go. ^CK-024 20 slot motherboard with edge connectors- unkit $174, assm $214 ^CK-025 12 slot motherboard with edge connectors - unkit $129, assm $169 ^CK-026 6 slot motherboard with edge connectors - unkit $89, assm $129 NOTE: Most CompuPro boards are available in unkil form (sockets, bypass caps pre-soldered in place), assembled, or I I qualified under the Certified System Component (CSC) high-reliability program (200 hour burn-in, more). I ENHANCED/ADVANCED Z-80A S-100 CPU BOARD Superior design in a true IEEE-compatible board (timing specs available on request) gives the power for future expansion as well as system flexibility. Includes all standard Z-80A features along with power on jump/clear, on-board fully maskable interrupts for interrupt-driven systems, selectable automatic wait state inser- tion, provision for adding up to 8K of on-board EPROM, 4 MHz operation, and IEEE compatible 16/24 bit extended addressing. $225 unkit, $295 assm, $395 CSC. SPECTRUM S-100 COLOR GRAPHICS BOARD 1 1 Includes 8K of IEEE-compatible static RAM; full duplex bidirec- tional parallel I/O port for keyboard, joystick, etc. interface; and 6847-based graphics generator that can display all 64 ASCII characters. 10 modes of operation, from alphanumeric/semi- graphics in 8 colors to ultra-dense 256 x 192 full graphics. 75 Ohm RS-170 line output and video output for use with FCC approved modulators. $339 unkit, $399 assm, $449 CSC. You don't have to settle for black and white graphics or stripped-down color boards; specify the CompuPro Spectrum. Want graphics software? Sublogic's 2D Universal Graphics Inter- preter (normally S35) is yours for $25 with any Spectrum board purchase. OTHER S-100 BUS PRODUCTS Godbout Computer Enclosure Active Terminator Board 2708 EPROM Board (less EPROMs) Memory Manager Board 2S "Interfacer I" I/O Board 3P Plus S "Interfacer 11" I/O Board Mullen Extender Board Mullen Relay/Opto-lsolator Control Board. . Vector 8800V S-100 Prototyping Board $289 desktop, $329 rack mount $34.50 kit $85 unkit $59 unkit, $85 assm, $100 CSC $199 unkit, $249 assm, $324 CSC $199 unkit, $249 assm, $324 CSC $59 kit $129 kit, $179 assm $19.95 NEW ! S-100 DUAL PROCESSOR CPU BOARD The Dual Processor Board is here . . . and CPU boards will never : be the same again. 8088 CPU gives true 16 bit power with a stan- ■.. ■ •■ dard 8 bit S-100 bus; an 8085 gives compatibility with CP/M and 8080 software. Accesses up to 16 megabytes of memory, meets ;■:: all IEEE S-100 bus specifications (timing specs available on >■■ request), runs 8085 and 8086 code in existing mainframe as well ■;.. as Microsoft 8086 BASIC and Sorcim PASCAL/M'^>, runs at 5 MHz for speed as well as power, and is built to the same stringent stan- dards that have established our leadership in S-100 bus com- ponents. $385 unkit, $495 assm, $595 CSC. 8085 single processor version of above: $235 unkit, $325 assm, $595 CSC. PASCAL/M^" + MEMORY SPECIAL PASCAL - easy to learn, easy to apply - can give a microcom- puter with CP/M more power than many minis. We supply a total- ly standard Wirth PASCAL/M"^ 8" diskette by Sorcim, with manual and Wirth's difinitive book on PASCAL, for $150 with the pur- chase of any memory board. Specify Z-80 or 8080/8085 version. PASCAL/M^^ available separately for $175. 16K DYNAMIC RAM SPECIAL: 8/$59: Expand memory in TRS-80* -I and -11, as well as machines made by Apple, Exidy, Heath H89, newer PETs, etc. Low power, high speed (4 MHz). Add $3 for 2 dip shunts plus TRS-80* conversion instructions. -TKS ao ,s .■> uatlmMrk .f itic Un6y C«rpoMt.on. TERMS: Cal res add tax. Allow 5% for shipping, excess refunded. VISA®/Mastefcard® orders ($25 mm) call (415) 562-0636, 24 hrs. COD OK with street address for UPS. Prices good through cover month of magazine. SEE COMPUPRO QUALITY FOR YOURSELF AT FINER COMPUTER STORES WORLD-WIDE . . . AND WATCH FOR OUR AMAZING MULTIFUNCTION BOARD ANNOUNCEMENT IN OCTOBER ! CompuPro" BIdg. 725, Oakland Airport, CA 94614 ^^ ELECTRONICS ^ Circle 86 on inquiry card. BYTE September 1980 175 The Working iitory* ¥^ Here's a straightforward stock control solution that will replace stacks of paperwork while helping you control your expensive inventory. Today's money costs make inventory carrying costs more burdensome than ever. And the cost of inventory control personnel isn't exactly going down, either. Now you can enter your stock additions and depletions once, at the keyboard of your microcomputer. You'll get automatic re-order reports (to show you what you need), complete inventory parts listings and valuations (to show you what you have), and activity reports (to show what's moving). You'll worry less, because you'll know more. The Inventory Control System includes an auditability option, extensive error screening, and reliable documentation. It was designed for people, not for programmers. Call or write SSG for a complete System Summary and the names of your closest dealers. There are over 150 nationwide. The Inventory Control System is por-t of o full line of working softwore solutions from Structured Systems Group, all reody to run on ony CP/M* microcomputer system. CP/M is o registered trademork of Digitol Reseorcfi, Structured Systems 5204 Claremont Oakland, Ca 94618 (415) 547-1567 Circle 110 on inquiry card. satisfaction, or problems en- countered in such a system, I am sure I would find it very useful. My main problem in try- ing to choose a computer system is in deciding be- tween two very diverse opinions. One opinion is that for a system as I have specified, I need a computer with 64 K bytes of memory and two 8-inch double- density floppy-disk drives for about one million bytes of storage. This would run in the neighborhood of $8000 in hardware (com- puter, printer, and terminal). The other major opinion is that I could get by with 50 K bytes of memory and 50 K bytes of storage; ie: a system that would sell for $1500 (such as the Intecolor 3600 Series from Intelligent Systems Corporation). If you could give me any answers these questions, I would greatly appreciate it. Thank you for your time. Laurie A Miller It looks to me as though you already have a good idea what kind of computer you need. At least 48 K, preferably 64 K, bytes of memory are required plus dual disks. If your data base is exceedingly large, or a large portion of it must be on-line at one time, make sure you choose a system that is expandable. This could include two more floppy-disk drives or a lO-megabyte or larger Win- chester hard disk. If because of finances you choose to start small, select a system that does not require a masters degree in electrical engineering to expand. Time of execution is generally the only real difference between large and small computers. The more disks you have to sort through to find the data you want, the longer it takes to get an answer. The software you want sounds like specific applications of generally available account- ing and data-base manage- ment programs. Hardware is only one part of the consideration however. Be aware that you are configuring a classic small-business system and the inventory and data-base management programs would be similar to, say, a dairy cooperative. While the choice of the hardware is important, adequate soft- ware and system maintenance are more signfi- cant in the long run. Once the computer is installed it is very easy to become depen- dent upon it working. There are many com- puters on the market that will satisfy your re- quirements: Cromemco, Hewlett-Packard, and Data General to name a few. The larger computer stores not only sell equipment like this, but offer custom program- ming and on-call field ser- vice as well. Take the time to evaluate the post-sale support for your computer, and check to see if your software will be compatible with other systems. I do not know much about cattle, but the com- plaints I've herd — oops! — heard from small- business computer users have been registered. ..SteveB 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 nagging problem? Send your inquiry to: Ask BYTE c/o Steve Ciarcia POB 582 Glastonbury CT 06033 If you are a subscriber to Tlie 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. Now NRI takes you inside the world's most popular microcomputer to train you at home as the ^ new breed of computer specialist! NRI teams up with Radio Shack to teach you how to use, program and service microcomputers . . .make you the complete technician. It's no longer enough to be just a programmer or a technician. With micro- computers moving into the fabric of our lives (over200,000 of theTRS-80™ alone have been sold), interdisciplinary skills are demanded. And NRI can prepare you with the first course of its kind, covering the complete world of the microcomputer. Learn At Home in Your Spare Time With NRI training, the program- mer gains practical knowledge of hard- ware, enabling him to design simpler, more effective programs. And, with advanced programming skills, the technician can test and debug systems quickly and easily lining includes TRS-SO computer, transistorized volt-ohm meter, digital frequency counter, and the NRI Discovery Lab with hundreds of tests and experiments. (TRS-80 is a trademark of the Radio Shack division of Tandy Corp.) Only NRI gives you both kinds of training with the convenience of home study No classroom pressures, no night school, no gasoline wasted. You leam at your convenience, at your own pace. Yet you're always backed by the NRI staff and your instructor, answering questions, giving you guidance, and helping you over the tough spots. Explore the TRS-80 Inside and Out NRI training is hands-on training, with practical experiments and demon- strations as the very foundation of your knowledge. You don't just program your computer, you introduce and correct faults . . .watch how circuits interact. . .interface with other systems. . .gain a real insight into its nature. You also build test instruments and the NRI Discovery Lab, performing over 60 separate experiments in the process. You leam howyour trouble-shooting tools work, and gain greater understanding of the in- formation they give you. Both micro- computer and equipment come as part of your training for you to use and keep. Send for Free Catalog. . . No Salesman wm Call Get all the details on this exciting course in NRI's free, 100-page catalog. It shows all equipment, lesson outlines, and facts on other electronics courses such as Complete Communications with CB, TV and Audio, Digital Electronics, and more. Send today, no salesman will ever bother you. Keep up with the latest technology as you leam on the world's most popular computer. If card has been used, write to: NRI Schools McGraw-Hill Continuing Education Center 3939 Wisconsin Avenue Washington, D.C. 20016. tin\M H & E CQIYIPUTHQI^JICS N • • • EVERYTHING FOR YOUR TRS-80 • • • TRS 80 Is a trademark of the Radio Shack Division of Tandy Corporation * All Orders processed within 24-Hours * 30-Da\; Money; Back Guarantee on all Software (less a $3 penalty; for handling) * 10-Da}; Mone\; Back Guarantee on Disk Drives and Printers PLUS 120-Da};s Free Service ' LEARNING LEVEL II By David Lien The Original Author Of The Level Manual A Step By Step approach to Learning Level II especially geared to nevi^ TRS-SO'" Ovi^ners $15.95^ FROM APPARAT NEW DOS + $99.95 ! 35, 40 and 77 Track Versions available, NEW DOS/80 (With variable record length files, chainings and many other features $149.95 TRS-80 - DISK AND OTHER MYSTERIES Over 100 pages of indespensible information for disk ovi^ners. Learn to recover information from bad disks, hovi^ to make Basic programsunlistable! and 12 more chapters of never published tips and information. Written by H.C. Pennington. (For all Disk Owners). $22.50l NEW SBSG BUSINESS SYSTEM FOR MODEL OR MODEL II - IN STOCK - General Ledger - Accounts Receivable - Accounts Payable - Payroll - Inventory Control vi^ith Invoicing ' • Each module can be operated individually or as a coordinated SYSTEM. Turn-Key error catching operation for beginners. Complete manual and documentation accompany each program. Minimum System requirernents 2-Disk Drives for Model l...1-Disk Drive for Model II Each module can be formatted to span data on up to 4-Disk Drives Free 30-Day telephone consultation Call for complete specifications Model I Version $125.00 Per Module $495.00 Per System Model II Version $225.00 Per Module $995.00 Per System ^\^'J'sir>. DATA MANAGEMENT SYSTEMS - DMS replace index cards or any data requiring long lists of information. TBS In-Memory Information System (For Cassette Systems) $39.95 TBS Disk Data Manager (Requires 1 or more disk drives). ..Set up fast random access, files in minutes. Stores up to 320K of information on 4 Drives. Up to 10 fields and 255 characters per record. Supports upper and lovi^er case. RS-232 or TRS-232... Features complete editing $49.50 Personal Softvi^are CCA Data Management System.. .Completely user oriented, menu drive. 130 page Step By Step Manual. ..Capable of inventory control, sorting data, reporting data in nearly any form (for reports and mailing labels). Sorts data by up to 10 fields for zip code, balance due, geographic location or vi^hatever. Prints reports wWb subtotals and totals automatically calculated. Fast random access $75.00 FROM RACET COMPUTES ' REMODEL-PROLOAD - f=ienumbers program lines, combines programs. The only renumber program that vi^ill renumber the middle of a program. Specify 16K. 32K or 48K. Works with Cassette or Disk $34.95 ' GSF - Use in your Basic Programs for Instant Sorting (will sort 1000 items in 9 seconds). Other commands include Compress and Uncompress Data. Duplicate Memory. Display Screen Controls and Fast Graphic Controls $24.95 (For Cassette or Disk, specify 16K. 32K or 48K). ' DOSORT - All G.S.F. commands plus special Multiple Disk Sorting Routines $34.95 (Specify 32K or 48K) ' INFINITE BASIC - Adds 70 commands to your TRS-BO'" including Instant Sort, Matrix Commands, String Commands, Left and Right Justification, String Centering, Simultaneous Equations, Upper and Lower Case Reverse and more. (For Cassette or Disk) $49.95 ' INFINITE BUSINESS (Requires Infinite Basic) Eliminate Round-off error, 127-Digit Calculation Accuracy, Insert New Elements in Sorted Arrays, Automatic Page Headings, Footings and Pagination, Multiple Precision Arithmetic and more. (For Cassette or Disk) $29.95 ' COPSYS - Copy Machine Language Programs (For Cassette Only) $14.95 ' DSM (Disk Sort Merge) $75.00 l'4l'S^W»Sl*W'S^S^»»Sl»N FROM SMALL SYSTEM SOFTWARE RSM-2 Machine Language Monitor $26.95 RSM-2D Disk Version of RSM-2 $29.95 DCV-1 Converts Machine Language Programs from tape to disk $9.95 AIR RAID - The ultimate TRS-SO'" game converts your TRS-SO'" into a real time shooting gallery $14.95 BARRICADE - A fast pong style game $14.95 CPM - (For Disk Only) $150.00 TRS-232 INTERFACE - Interface with Software driver RS-232 printers to your TRS-SO'" $49.95 TRS-232 FORMATTER - Additional (optional) Software for TRS-232 owners. Adds many printer commands to your TRS-SO'" $14.95 (With purchase of TRS-232) $9.95 PENMOD - Use the Electric Pencil with RS's lower case modification $19.95 FROM GALACTIC SOFTWARE MAIL PAC - For Model I Disk Systems only $99.95 Quick-sorting full user control over mailing list from Galactic Software. STOCK MARKET PAC $99.95 CQIYIPJTHQWlCSi 50 N. PASCACK ROAD SPRING VALLEY, NEW YORK 10977 HOURS: 9-5 Monday thru Saturday aS'Page Catalog $2 FREE With An\; Order Order By Phone Or Mail Add $1 Per Order For Shipping Within UPS Areas Add $3 For COD. Add $3 For All Foreign And Non-UPS Shipments Add $3 For UPS Blue Label 178 BYTE September 1980 HOUR 24 ORDER LINE (914) 425-1535 NEW TOLL-FREE ORDER LINE (OUTSIDE OF N.Y. STATE) (800) 431-2818 FROM THE BOTTOM SHELF • CHECKBOOK II (For Cassette or Disk) $39.95; • SYSTEM DOCTOR (A completediagnosisof your TRS-SO'"... Checks memory, video, cassette, disk, ROM. and all other parts of your system) For Cassette or Disk $28.50 CHECKBOOK REGISTER ACCOUNTING SYSTEM (Requires 2 disk drives) $75.00 LIBRARY 100 - 100 established business, game and educational programs plus FREE Tiny Pilot all for $49.50 ; BASIC TOOL KIT - Lists all variables. GOTO's and GOSUB's in your program $19.80 SOUNDWARE - Adds sound to your TRS-80'- Just plus it in $29.95 Sample programs included. TING TONG - Can be used with Soundware for a Sound version of pong $9.95 '< VIC - The Carta Visual Instructional Computer Program $19.95 The Level II 16K Cassette is designed to teach beginners the Basics of Machine Language and Assembly Language Programming. See every Machine Language Instruction Display on your video. VIC includes Step By Step 55 page manual VISTA VBO DISK DRIVE - 11 OK of Storage $395.00 Add S29.95 for Cable (Free with purchase of 2-Disk Drives). 10 day money back guarantee. FROM HOWE SOFTWARE MON-3 - Machine Language Programming for beginners, MON-3 is a complete System Monitor with Users Manual $39.95 MON-4 - Disk Version of MON-3 $49.95 FROM MICROSOFT • LEVEL III BASIC $49.95 ; Now Cassette owners can add Disk Commands to their TRS-80'" without owning a Disk Drive • MICROSOFT DISK ADVENTURE $29.95 • TRSDOS BASIC COMPILER $195.00 Run Basic Programs up to 15 times faster. NEC BUSINESS QUALITY PRINTERS (For MOD-I or MOD-II) $2,995.00 THE ELECTRIC PENCIL Cassette Disk MOD-II Version $99.95 $150.00 $325.00 • HORSE SELECTOR II By Dr Hal Davis i The TRS-SO'" version updated for the TRS-80'" and originally reviewed in Systems and Methods $50.00 J :^ • • • EVERYTHING •TT' FOR MOD-II OWNERS >^Sf^^^ NEW MOD-II NEWSLETTER MOD-II Catalog Free w/subscription $1 2/year MAIL PAC $199.95 MICROSOFT BASIC COMPILER $395.00 MICROSOFT BASIC GSF SORT ROUTINE CP/M PEACHTREE BUSINESS SOFTWARE WORDSTAR $325,00 ; $50.00 ': $170.00; Calli $495.00 : Circle 111 on inquiry card. THE ORIGINAL MAGAZINE FOR OWNERS OF THE TRS-80 ''* MICROCOMPUTER SOFTWARE FORTRS-80" OWNERS H CQiriPUTHQI^ICS MONTHLY NEWSMAGAZINE Practical Support For Model I & II I N C. MONTHLY NEWSMAGAZINE FOR TR5-80 • OWNERS • PRACTICAL APPLICATIONS • BUSINESS • GAMBLING • GAMES • EDUCATION • PERSONAL FINANCE • BEGINNER'S CORNER • NEW PRODUCTS • SOFTWARE EXCHANGE • MARKET PLACE • QUESTIONS AND ANSWERS • PROGRAM PRINTOUTS AND MORE FBtt PROGRAMS AND ARTICLES PUBLISHED IN OUR FIRST 12 ISSUES INCLUDE THE FOLLOWING: A COMPLETE INCOME TAX PROGRAM (LONG AND SHORT FORM) INVENTORY CONTROL STOCK MARKET ANALYSIS WORD PROCESSING PROGRAM (FOR DISK OR CASSETTE) LOWER CASE MODIFICATION FOR YOUR VIDEO MONITOR OR PRINTER PAYROLL (FEDERAL TAX WITHHOLDING PROGRAM) EXTEND 16DIGIT ACCURACY TO TRS-SO'" FUNCTIONS (SUCH AS SQUARE ROOTS AND TRIGONOMETRIC FUNCTIONS) NEW DISK DRIVES FOR YOUR TRS-80^- PRINTER OPTIONS AVAILABLE FOR YOUR TRS-SO'" A HORSE SELECTION SYSTEM***ARITHMETIC TEACHER COMPLETE MAILING LIST PROGRAMS (BOTH FOR DISK OR CASSETTE SEQUENTIAL AND RANDOM ACCESS) RANDOM SAMPLING***BAR GRAPH CHECKBOOK MAINTENANCE PROGRAM LEVEL II UPDATES***LEVEL II INDEX CREDIT CARD INFORMATION STORAGE FILE BEGINNER'S GUIDE TO MACHINE LANGUAGE AND ASSEMBLY LANGUAGE LINE RENUMBERING AND CASSETTE TIPS. PROGRAM HINTS, LATEST PRODUCTS COMING SOON (GENERAL LEDGER. ACCOUNTS PAYABLE AND RECEIVABLE. FORTRAN 80. FINANCIAL APPLICATIONS PACKAGE, PROGRAMS FOR HOMEOWNERS. MERGE TWO PROGRAMS. STATISTICAL AND MATHEMATICAL PROGRAMS (BOTH ELEMENTARY AND ADVANCED) . . . AND WORD PROCESSING PROGRAM (Cassette or Disk) For writing letters, text, mailing lists, etc., with each new subscriptions or renewal. LEVEL II RAM TEST (Cassette or Disk) Checks random access memory to ensure that all memory locations are working properly. DATA MANAGEMENT SYSTEM (Cassette or Disk) Complete file management for your TRS-80'" CLEANUP (Cassette or Disk) Fast action Maze Game ADVENTURE (Cassette or Disk) Adventure nO by Scott Adams (From Adventureiand International) f^REH ' TRS-80- IS A TRADEMARK OF TANDY CORP SEND FOR OUR NEW 48 PAGE SOFTWARE CATALOG (INCLUDING LISTINGS OF HUNDREDS OF TRS-80^" PROGRAMS AVAILABLE ON CASSETTE AND DISKETTE). $2.00 OR FREE WITH EACH SUBSCRIPTIONS OR SAMPLE ISSUE. iCQMPJTHQMICS SO N. PASCACK ROAD SPRING VALLEY, NEW YORK 10977 HOUR 24 ORDER LINE (914) 425-1535 ONE YEAR SUBSCRIPTION $24 TWO YEAR SUBSCRIPTION $48 SAMPLE OF LATEST ISSUE $ 4 START MY SUBSCRIPTION WITH ISSUE (#1 - July 1978 • #7 - January 1979 • #12 - June 1979 • #18 - January 1980) NEW SUBSCRIPTION RENEWAL NEW TOLL-FREE ORDER LINE (OUTSIDE OF N.Y. STATE) (800) 431-2818 NEW!!! MOD-II NEWSLETTER $12/year Cor 12 issues) CREDIT CARD NUMBER . . EXP. DATE_ SIGNATURE. NAME ADDRESS _ _C(TY_ . STATE. » ADD $6/YEAR (CANADA. MEXICO) - ADD $12/YEAR AIR MAIL - OUTSIDE OF U.S.A., CANADA & MEXICO * Circle 111 on inquiry card. BYTE September 1980 179 FCC Regulation of Personal- and Home-Computing Devices New Rules After a 3-Year Study Terry G Mahn Wewer & Mahn PC 1762 Church St NW Washington DC 20036 If you have been reading BYTE within the last half year, you are probably aware that the FCC (Federal Communications Commission) has handed down a set of regulations pro- hibiting the sale of personal com- puters that emit unacceptable levels of RFI (radio-frequency interference). But the FCC has changed its regula- tions several times, and in any case, information on and interpretation of these rulings have been scarce. I hope to clarify these most recent FCC regulations and to describe how (and when) they will affect you as a About the Author Terry G Mahn is a principal in the law firm Wewer and Mahn PC in Washington DC, where he specializes in intellectual property protection and licensing, and the legal, regulatory, and policy issues affect- ing the data processing and telecommuni- cations industries. He has previously served as general counsel to the Computer and Communications Industry Associa- tion and as a computer specialist for the US House of Representatives Committee on House Administration. Currently, he is regulatory counsel to MITA (Micro- computer Industry Trade Association). It is current FCC policy for computer manufac- turers to bear the associated costs of their technology. personal-computer user or vendor and the industry in general. It is a common misconception by many in the computer industry that the FCC is empowered by the 1934 Communication Act only to regulate communications providers and users — that is, common carriers, broadcasters, and Citizens Band radio users. This misconception emanates from the nearly decade-old controversy surrounding the Com- mission's so-called "Computer Rules." First adopted in 1971, these regulations attempted to define the technological boundary line between common-carrier communications and data processing, to identify the FCC's jurisdictional perimeter under Title II (common-carrier services) of the Act. Recently, the computer rules have un- dergone a major revision in an effort to halt FCC encroachment into the traditionally nonregulated computer and data-processing industries. The FCC's regulatory reach into the computer industry, however, is not as limited as the Computer Rules might seem to indicate. Title III of the Act (radio services) specifically em- powers the FCC to protect communi- cations systems from RFI, from what- ever source derived. Insofar as virtu- ally all computing devices emit spuri- ous radio frequencies that can poten- tially interfere with radio or televi- sion services, manufacturers and ven- dors of such equipment come directly within the FCC's Title 111 jurisdiction. It is not axiomatic that where fed- eral authority exists, industry regula- tion and increase of the cost of doing business is sure to follow. (Under Chairman Ferris, for example, the FCC has been particularly notorious in reducing regulation of American industry.) Nevertheless, the FCC has chosen to regulate in this area for purely economic reasons. Because the radio spectrum is a valuable, but lim- ited resource that can be used in vari- ous but incompatible ways, simple economic efficiency suggests that such resources be employed in their 180 September 1980 © BYTE Publications Inc Start learning and computing for only $129- 95 ^^^h a Netronics 8085-based computer kit. Then expand it in low-cost steps to a business/ development system with 64k or more RAM, 8" floppy disk drives, hard disks and multi- terminal I/O. THE NEW EXPLORER/85 SYSTEM Special! FuiJ 8" floppy, 64k system for less than the price of a mini! Only $1499.95! Imaeine — for only $129.95 you can own the starting level of Explorer/85, a computer that's expandable into full business/development capabilities — a computer that can be your beginner system, an OEM controller, or an IBM-formatted 8" disk small business system. From the first day you own Explorer/85, you begin computing on a significant level, and applying princi- ples discussed in leading computer magazines. Ex- plorer/85 features the advanced Intel 8085 cpu. which is 100% compal ible with the older 8080A. It offers on- board S-100 bus expansion. Microsoft BASIC in ROM. plus instant conversion to mass storage disk memory with standard IBM-formatted 8" disk.s. All for only $129.95, plus the cost of power supply, keyboard/ terminal and RF modulator if you don't have them (see our remarkable prices below for these and other, ac- cessories). With a Hex Keypad/display front panel, Level "A" can be programmed with no need for a ter- minal, ideal for a controller. OEM. or a real low-cost .start. ^^tsr "^^i^, l^vci "/\" is a ■^ complclc operaljnfl system, perfect for beginners, hobbyi.sfs, industrial controlhir use. 5129.95 (Also available wired & tested. $1799.95) V Full 8" disk sysfem for less than the price of a mini (shown with Netronics Explorer/as computer and new terminal). Sysfem faatures floppy drive from Contvol Data Cojp., world's largest maker of memory slorugu sy.slems ( not a hohhy linind') lj;vel "A" With Hex Keypad/Display. LEVEL "A" SPECIFICATIONS Explorer/85's Level "A" system features the advanced Intel 8085 cpu. an 8355 ROM with 2k deluxe monitor/ operating system, and an advanced 8155 RAM I/O . . . all on a single motherboard with room for RAM/ROM/ PROM/EPROM and S-100 expansion, plus generous prototyping space. PC Board: Glass epoxy. plated through holes with solder mask. • I/O: Provisions for 25-pin (DB25) con- nector for terminal serial I/O. which can also support a paper tape reader . . . cassette tape recorder input and output . . . cassette tape control output . . , LED output indicator on SOD (serial output) line . . . printer inter- face (less drivers) . . . total of four 8-bit plus one 6-bit 1/0 ports. • Crystal Frequency: 6.144 MHz. • Control Switches: Reset and user (RST 7,5) interrupt . . . addi- tional provisions for RST 5.5. 6.5 and TRAP interrupts onboard. • Counter/Timer: Programmable, 14-bit bi- nary. • System RAM: 256 bytes located at F800. ideal for smaller systems and for use as an isolated stack area in expanded systems . . . RAM expandable to 64K via S-100 bus or 4k on motherboard. System Monitor (Terminal Version): 2k bytes of deluxe system monitor ROM located at Fj800. leaving ^^ free for user RAM/ROM. Features include tape load with labeling . . . examine/change contents of memory . . . insert data . . . warm start . . . examine and change all registers . . . single step with register display at each break point, a debugging/training feature ... go to execution address , . . move olocks of memory from one location to another . , . fill blocks of memory with a constant . . . display blocks of memory . . . automatic baud rate selection to 9600 baud . . . variable display line length control (1-255 characters/line) . . , chan- nelized 1/0 monitor routine with 8-bit parallel output for high-speed printer . . . serial console in and console out channel so that monitor can communicate with I/O ports. System Monitor (Hex Keypad/Display Version): Tape load with labeling . . , tape; dump with labeling . . . examine/change contents of memory . , . insert data . . . warm star . . . examine and change all regi.sters . . . single .step with regi.ste^r display at each lireak point . , . go to excjcution address, Level "A" in this version makes a perfect controller for industrial applications, and is programmed using the Netronics Hex Keypad/ Display. It is low cost, perfect for l^eginners. HEX KEYPAD/DISPLAY SPECIFICATIONS Calculator type keypad with 24 system-f^efined and 16 user-defined keys. Six digit calculator-type; display, that displays full address plus data as well as register and status information. LEVEL "B" SPECIFICATIONS Love! "B* provides the S-100 .signals plus buffers/ drivers to support up to .six S-100 bus boards, and in- clud(;s: address decoding for onboard 4 k RAM expan- sion selectable in 4k blocks . . . addre.ss decoding for onboard Hk EPROM expansion selectable in Hk blocks . , . address and data bus drivers for onboard expansion . . . wait stategenerator()umper selectable), to allow the use of slower memories . . . two separate 5 volt regula- tors. LEVEL "C" SPECIFICATIONS Level "C " expands Explorer/85's motherboard with a card cage, allowing you to plug up to six S-100 cards directly into the molherlioard. Doth cage and card are neatly contained inside Explorer's deluxe: steel cabinet. Level "C " includes a .sheet metal superstruc- ture, a 5-card. gold plated S-100 extension PC board that plugs into the motherboard, just add required number of S-100 connectors. LEVEL "D" SPECIFICATIONS Level "D" provides 4k of RAM. [X)wer supply regula- tion, filtering decoupling components and sockets to expand your Explor(;r/n5 memory to 4k (plus the origi- nal 256 iiyles located in the 8155A). The static RAM can lie located anywherf; from l60jlf0 to EFFF in 4k blocks. LEVEL "E" SPECIFICATIONS Level "E " adds sockets for 8k of EPROM to use the popular Intel 2716 or the Tl 2516. It includes all sockets, power supply regulator, heat sink, filtering and decou- pling components. Sockets may also be used for 2k x 8 RAM IC"s (allowing for up to 12k of onboard RAM). DISK DRIVE SPECIFICATIONS • 8" CONTROL DATA CORP. • Dalacapacity:401.016byres professional drive. (SD). 802,032 bytfis (DD), • LSI controller. unformatted. • Write protect. • Access time: 25m.s (one • Singleor double density. track), DISK CONTROLLER/ I/O BOARD SPECIFICATIONS • Conl.olsup to fours" drives. • 2716 PROM socket included • 1771 ALSI (SD) floppy disk for use in ciislom controller, applications. • Onboard data separator • Onlroard crystal controtietf. (IBM compatible). • Onboard I/O baud rale • 2 Serial I/O ports generators lo 9600 baud. • AutohooHo disk system • Double-sided PC board Vkfhen system reset. (glass epoxy.) DISK DRIVE CABINET/POWER SUPPLY • Deluxe steel cabinet writh individual pov^er supply for miix- imum reliability and slabililjr. ORDER A COORDINATED EXPLORER/85 APPLICATIONS PAK! Beginner's Pak (Save $26.00!)— Buy Level "A" (Ter- minal Version) with Monitor Source Listing and AP-1 5-amp Power Supply: (regular price $199.95). now at SPECIAL PRICE: $169.95 plus post. & insur. Experimenter's Pak II (Save 553.40!) — Buy Level "A" (Hex Keypad/Display Version) with Hex Keypad/Display. Intel 8085 User Manual. Level "A" Hex Monitor Source Listing, and AP-1 5-amp Power Supply: (regular price $279.35). all at SPECIAL PRICE: $219.95 plus post. & insur. Special Microsoft BASIC Pak (Save $103.00!) — In- cludes Level "A" (Terminal Version). Level "B". Level "D" (4k RAM). Level "E". 8k Micro.soft in ROM. Intel 8085 User Manual. Level "A" Monitor Source Listing, and AP-1 5-amp Power Supply: (regu- lar price $439.70). now yours at SPECIAL PRICE: $329.95 plus post. & insur. ADD A TERMINAL WITH CABINET, GET A FREE RF MODULATOR: Save over $114 at this SPECIAL PRICE: $499.95 plus post. & insur. Special 8" Disk Edition Explorer/85 (Save over $104!) — Includes disk-version Level "A", Level "B". two S-100 connectors and brackets, disk controller. 64k RAM. AP-1 5-amp powersupply. Explorer/85 deluxe steel cabinet, cabinet fan. 8" SD/DD disk drive from famous CONTROL DATA CORP. (not a hobby brand!), drive cabinet with power supply, and drive cable set-up for two drives. This package includes everything but terminal and printers (see coupon for them). Regular price $1630.30, all yours in kit at SPECIAL PRICE: $1499.95 plus post. & insur. Wired and tested, only $1799.95. Special! Complete Business Software Pak (Save $625.00!) — Includes CP/M 2.0. Microsoft BASIC. General Ledger. Accounts Rec(rivable. Accounts Payable. Payroll Package: (rcjgular pric(jSl325). yours now at SPECIAL PRICE: $699.95. Please send the items checked below. D ExpIorer/B5LEveI"A"kll(Teiminitl Vnr.sion). . . $129.95 plus S3 post. & insur. a Explorer/85 level "A" kit (Hex Keypad/Disphiy Version) . . , $129.95 plus S3 post. & insur. D 8k Microson BASICon ciissntln tapn. S64.95 postpaid. D 8k Microsoft BASIC In ROM kJt (requires LevdsB", ■D" and "E") . . . $99.95 plus S2 post. & insur. D Level "B" (S-100) Wl. . . M9.95 plus S2 post. & insur. D Level "C" (S-lOO 6-card expander) Ml . . S39.95 pi us S2 post. & insur. D Level "D" (4k RAM) kit , . . $69.95 plus S2 paal & insur. D Level "E" (EPROM/ROM) kit . . . $5.95 plus r)0 as above, plus ASCII Keyboard l^rmlnal With Cabinet, Gel Free RF Modulator {mnt above) . . . $499.95 plus SlO post. & insur. D Special 8 ' Disk Edition Explorer/B5 (see al)ove) . . $1499.95 plus 526 post. & insur. n Wired &1feSied. . , S 1 700.95 plus S26 post. & insur. D Ext ra&" CDC Floppy Drives . , i490.95 plus Si2 |X)sl. 8c insur. D Cabinet & I«ower Supply For Drive . . $69. 95 pi us S3 post. ^ insur. D Drive Cable Set-up For IWo Drives ... $25 plus si. so post. & msur, a Disk Controller Board Willi I/O Pons. . . $199.95 plus S2post & insur. D Special: Complete Business Software Pak (s(!e above) $699.96 postpaid. SOLD SEPARATELY: DCP/M 1.4... $100 postpaid. D CP/M 2.0... $150 postpaid. D Microsoft BASIC. . . $325 postpaid. D Intel 8085 cpu User Manual . . . S7.50 postpaid. D Level "A" Monitor Source Listing ... $25 postpaid. ^g Continental U.S.A. Credit Card Buyers Outside Conn(H:ltcul ^. ■ CALL TOLL FREE: 800-243-7428 m ^1 To Ordi^r From Connecticut O r For Tiichnical ^V ^ Assistance., call (203) ;}54-9375 ^ Tolal Enclosnd (Conn res. add sales lax) S Paid By: D Pnrsonal Chnck D Cashitir'.s Ch(K:k/Monny (3rcl(;r n VISA D Master Charge (Bank No '. ) Acct. No. Exp. Dat(! . Signature Print Name Adilr(;.s.s Cily- Slat(! - '^iP- NETRONICS Research & Development Ltd. 333 Litchfield Road, New Milford, CT 06776 most valuable way — namely, in the way that yields the greatest public benefits. Just as raising a crop of corn and grazing cattle are incompatible uses of the same plot of land, so too may the operation of a computing de- vice and the transmission of televi- sion signals present incompatible uses of the electromagnetic spectrum. The FCC, therefore, is forced to balance the demands placed on electromag- netic spectrum usage by American businesses and consumers: the dif- ficulty arises in determining which use will yield the greatest public benefits. Consider, for example, the follow- ing possible public-cost/benefit scenarios involving computing devices and communications services: • A suspected criminal is being pur- sued by police through winding city streets. Several patrol cars begin converging on the suspect from different directions as information on the suspect's loca- tion and movement is relayed over the police radio band. Sud- denly, the suspect makes an abrupt turn through the parking lot of a cocktail lounge. Before the pursuing car can com- municate the suspect's sudden (tall on John D. Owens for all Your Computer Needs COMPUTERS, PRINTERS, CRTs, MODEMS, MAINFRAMES, MEMORY, CONTROLLERS, FLOPPY AND HARD DISK DRIVES, I/O, DISKETTES AND SOFTWARE. IMS 5000 and 8000 Systems The new rising stars! Beautifully designed and constructed with the Industrial Micro System reputation for fine quality. These systems feature a Z80 CPU, S-100 bus; double density drives (either single or double sided) CP/M®. 5000 series uses mini floppies, 8000 uses maxi floppies. Hard disk and MP/M now available. Model 5-00125 with two double density drives, 32K Static RAM $2,765 Model 8-00125 as above but with 8" drives $4,185 Other configurations available. TELETYPE Model 43 Inventory Sale!!! Model 4320 AAK $1,085 Model 4330 punch/ reader. 10 or 30 CPS. 8 level, 1" tape $2,595 Limited supply of Model 45 available. DRIVES Per Sei299B Now Available!!! . . . $2,200 Cabinetandpowersupply $300 PerSci277 $1,210 Siemens $395 Shugart $525 MPI B51 . . . . $265 B52 $365 Innotronics and QUME also available HAZELTINE 1500 $885 1510 $980 1520 $1,210 DEC LA 35/36 Upgrade $750 Increases baud rate to 1200. Microproces- sor controlled. Many features include TOP, tabs and margin control. We have no reader inquiry number. Call on us for product sheets. Dealer inquiry invited. Prices subject to change without notice. IBM 3101 CRT Model 10 $1,195 Model 20 $1,395 Selectric-like, detached keyboard. 9x16 dot matrix. Maintenance contract from IBM only $70 per year. TELEVIDEO SMART CRTs 912 B and C $780 920 B and C . . $850 IMS MEMORY 16 K static ... 32 K static 64 K Dynamic with parity . . . .. $285 . . $585 . . $950 TEI MAINFRAMES, S-100 12 slot . . $500 22 slot . . $670 TARBELL Double density controller . $420 CODs accepted at no extra charge. Shipping $14 for light printers and CRTs . Credit cards add 4%. NY residents add tax. WE EXPORT: Overseas Callers: Phone 212 448-6298 TWX 710 588 2844 or Cable: OWENSASSOC We Are Known for Our Prompt and Courteous Service! JOHN p. OWENS 212 448-6283 AsSOCiatCS, Inc. 212 448-6298 12 Schubert Street ■"JTM Staten Island, New York 10305 movement, however, in- terference crackles over the police band, drowning out all com- munications for several seconds. When the band finally clears, the police learn that they have lost track of the fleeing suspect. Later, the police investigate the cause of the interference on their restricted band and learn that one of the coin-operated video games in the cocktail lounge was the source of the interfering radio frequencies. • An airplane pilot finds himself caught in bad weather and is forced to make an "instrument" landing. As the pilot approaches the airfield, he asks his copilot to render a quick computation to better gauge their position. The control tower, which has the plane on radar, warns the pilot of an approaching larger aircraft. Suddenly, before the tower's automatic collision-avoidance instructions are received, inter- ference drowns out the radio channel. While waiting for the channel to clear, the pilot nearly collides with a commercial airlin- er but manages to land safely. The FAA (Federal Aviation Ad- ministration) later conducts an investigation and learns that the electronic calculator used by the copilot emitted the RFI that caused the interference on the re- stricted aeronautical-frequency band. • A young mathematics student re- ceives a personal computer for his fifteenth birthday. Shortly thereafter his entire family begins to use the computer for various applications: the father does tax and financial planning for his insurance clients; the mother stores cooking recipes and ad- dresses and telephone numbers of friends and relatives; and the younger brother plays electronic video games. Soon, even the family's home-security and energy-control systems are being run by the computer. Meanwhile a neighbor complains to an FCC field office that he has been ex- periencing interference each evening over one of his local television channels. The field office investigates and learns that the personal computer is the source of the RFI. The family is told to correct their computer or discontinue its use. Since the 182 Seplember 1980 © BYTE Publicalions Inc manufacturer's warranty does not cover RFI defects, the family is forced to undertake expensive corrective measures of their own. While these examples may seem a lit- tle contrived, in fact, each concerns a theoretical situation with which the FCC is concerned. Moreover, in every case brought to the FCC's attention involving RFI from computers, the FCC has rou- tinely decided that radiation from such devices is a less valuable use of the spectrum than the radio-commun- ication services which might be in- terfered with. Stated another way, it is current FCC policy for computer equipment manufacturers to bear the associated costs of their new and beneficial technology. Computing Device Interference Computers and other similar devices emit potentially harmful radio-frequency signals. Inside a computer, very rapid electrical signals and pulses are generated and used to regulate sequences of events and to carry out the control and logic functions of the computer. These rapid electrical pulses produce high- frequency emissions that "float" around inside the cabinet of the com- puter. Unless this energy is somehow contained or filtered, it is radiated in- to space to be picked up by radio or television receivers. Computers have been reported to cause harmful interference to almost all radio services, particularly those services below 200 MHz, including police, aeronautical, and broadcast services. Several factors that have contributed to the recent increase in computer-interference complaints include: • the proliferation of digital elec- tronic equipment in both businesses and homes; • the development of higher-speed computers, which require designers to contend with prob- lems of radio-frequency emission never before experienced; • the increased replacement of steel cabinets with plastic cabinets, which provide little or no RFI shielding. To the extent that computing devices are harmful in terms of their potential for generating RFI, and because private mediation between interfering uses is considered highly unlikely, the FCC becomes the final arbiter of spec- trum interference. Part 15 of the Commission's Rules specifically addresses these concerns by setting forth various technical and administrative specifications for all devices that generate or use radio- frequency energy. Computer and other digital devices not intended to radiate RFI are defined as restricted- radiation devices. Until very recently, however, restricted-radiation devices were subject to technical performance standards first drafted by the FCC in 1938. In further complication of mat- ters, under these 40-year-old rules, personal computers are subject to vastly different technical standards depending on whether they contain their own video displays or connect to an external television set. Three years ago the FCC initiated a rule-making procedure to modernize its Part 15 rules and to render them more workable and nondiscrimina- tory in our evolving electronic society. The proceeding was recently concluded with the adoption of new regulations that will affect all com- puter manufacturers. Hardest hit. Call on John D. Owens for all Your Computer Needs We Are Known for Our Prompt and Courteous Service! PET COMPUTERS INVENTORY SALE - LIMITED QUANTITIES PET 2001N 32K S950 DUAL DISK SYSTEM S950 COMPLETE PET BUSINESS PACKAGE 31 fully integrated programs including Inventory, Sales summary, Accounts Receivable/payable, tax statements, general ledger, etc. etc. Prompts user. Validates each entry. Menu driven S750 ATARI AUTUMN SALE Computer, Model 800 . Disk Drive, Model 810. Printer, Model 820 Cassette, Model 410 . . . Paddle Controller Pair . LIST PRICE SALE PRICE Si, 080 S845 S 699 S545 S 599 S457 S 89 S 75 S 19 S 17 MARINCHIP SYSTEMS M9900 Elegant 16 bit CPU, S-100 compatible Multi user, multi processor operating system. Extended precision commercial BASIC FORTH, MET A, PASCAL, Word Processor and Text Editor. Fast and powerful! Complete kit and software package S550 Assembled S700 We configure complete systems with floppy or hard disk. HAWKEYE GRAFIX COMMUNICATIONS SOFT- WARE FOR 8080/Z80/CP/M® Enables communications with a time sharing system thru Modem port. Modes of operation: TERMINAL (your system acts like an intelligent terminal), FILE-TO-FILE, LOCAL (Disk commands), Full/Half Duplex on 8" or 5" disks COM to COM mode does full CRC 16 error check and retransmits block on error. Binary Code S75 Source Code ...... .S150 MICROANGELO $1,795 High resolution graphics system. Microangelo feature 15", 22MHZ, green phospher screen, 72 key keyboard; includes complete cabling and software. From SCION. INDUSTRIAL MICRO SYSTEMS TELETYPE HAZELTINE IBM TELEVIDEO TEl TARBELL SIEMENS PER SCI NEC ITHACA INTERSYSTEMS MARINCHIP DATA SOUTH QUME CENTRONICS TEXAS INSTRUMENTS ATARI DEC CALIFORNIA COMPUTER SYSTEMS KONAN EDGE TECHNOLOGY INNOTRONICS XEROX DIABLO INTEGRAL DATA SYSTEMS CROMEMCO SOROC MICROPRO TELETEK NOVATION FUJITSU CDC NORTH STAR COMMODORE SCION MPI POWER ONE MEASUREMENT SYSTEMS AND CONTROL SEE OUR AD AND ORDERING DETAILS ON FACING PAGE! JOHN p. OWENS 212 448-6283 AsSOCiatCS, IllC. 212 448-6298 12 Schubert Street, Staten Island, New York 10305 September 1980 © BYTE Publications Inc 183 however, will be the personal- computer industry. FCC Classification of Computing Devices In order to establish RFI standards that are appropriate for a given com- puter's actual harm-causing potential, the Commission has classified all computing devices under a binary scheme: Class A devices are defined as computing devices used in com- mercial environments, and Class B devices are defined as those used in a residential environment or widely marketed to the public. The basis for this dual classification scheme is rooted in the theory that Class B (consumer) devices are located in closer proximity to radio, television, and (in many cases) land- mobile radio services and thus have a higher potential for causing in- terference than do Class A (commer- cial) devices. Additionally, the Com- mission has reasoned that consumer products usually do not contain the technical sophistication found in commercial equipment, nor do they receive the same level of preventive maintenance. In recognition of these important differences, between consumer and commercial products, the FCC has imposed technical standards on con- sumer equipment that are ten times more stringent than those standards imposed on commercial equipment. More importantly perhaps, the Com- mission is requiring manufacturers of consumer devices to register their products with the FCC by January 1, 1981 or cease all marketing; no similar rule applies to manufacturers of commercial computing equipment. (In addition, the FCC rules further distinguish between Class B "personal computing" devices that contain their own video displays and those that connect to a standard home television receiver (so-called Class I TV devices), with the latter being subject to somewhat stricter rules. Such distinctions between personal- computing devices should soon disap- pear, pending the successful comple- tion of an on-going rulemaking in this area.) The Regulatory Scheme for Com- puting Equipment The FCCs regulatory scheme for Computer Hardware Professionals Our clients, highly successful manufacturers and OEMs of Computer Systems, Electronic Systems, and Peripherals, have immediate openings for Hardware Development Professionals to work on FUTURE SYSTEMS PROJECTS. Such nrojecta include COMPUTER ARCHITECTURE, DATA COMMUNICA- TIONS, PERIPHERAL DEVELOPMENT, and POWER SUPPLY DESIGN. Specific openings currently exist at Senior and Intermediate levels for: COMPUTER ARCHITECTS — Definition and development of Micro- Mini-computer systems. POWER SUPPLY DESIGN ENGINEERS — Switching regulators for Off-Line Power supplies. Experience in High Frequency P.W.M. techniques and AC Power Distribution would be desirable. MICROPROCESSOR DESIGN ENGINEERS — Design/Development of state of-the-art Microprocessor based systems and interfaces. Experience on any Microprocessor acceptable. LSI DESIGN DEVELOPMENT — Numerous positions with local systems oriented firms in LSI technology development. CPU DESIGN ENGINEERS — BSEE/BSCS and/or experience in the design of Digital Computers or Microprocessor systems. Requires an understanding of Software, i.e. ASSEMBLY, FORTRAN, or PL-1. DIGITAL LOGIC AND CIRCUIT DESIGN ENGINEERS - Logic and Circuit design plus a familiarity with TTL, CMOS. LSIA^LSI, etc. ANALOG DESIGNERS — 30 to 40 megahertz Phase Lock loop experience. Experience with 80 megahertz power drivers and DC motors. PCB DESIGNERS - With CAD experience. COMMUNICATIONS SYSTEMS DEVELOPERS - Experience with store and forward message swit- ching. Network Data Link Control, and/or PBX and EPX Systems. Compensation on all positions ranges from low 20's to low 40's, based upon experience. Client companies are equal opporLunity/afiirmative action employers, provide excellent benefits, and assume all fees. Qualified applicants will receive IMMEDIATE RESPONSE and are invited to contact: Don Bateman, in strict confidence, at (617) 861-1020. Or submit current resume to him for review. For those who find it in- convenient to call during working hours, our office will be open until 7:30 p.m. Rb Contact: Don Bateman Robert Kleven and Co., Inc. INDUSTRIAL RELATIONS MANAGEMENT CONSULTANTS Three Fielrher Avenue. Lexington. MaHsarhusellK 0217;} Telephone (f)I7t H(iMQ2() computing devices consists of both technical standards and adminis- trative procedures. The technical standards are designed to minimize the likelihood that computing devices will cause interference with any FCC- authorized communications services. Therefore, standards for radiation as well as conduction (ie: through a building's wiring) limit the amount of radio frequency that computing devices will be permitted to emanate during their normal operation. The administrative procedures adopted by the FCC are intended to ensure that manufacturers comply with the appropriate technical stan- dards; these procedures also apprise the users of each class of equipment of its interference potential and what to do in case of technical failure. Most important, however, are the compliance deadlines that manufac- turers must meet in order to continue (or begin) advertising and marketing their computing equipment. As ex- plained more fully below, the rules differ substantially between commer- cial and consumer equipment, with the latter being subject to more strin- gent requirements. Class Definition Distinctions The FCC defines a "computing device" to be any electronic system that generates timing signals or pulses in excess of 10,000 cycles per second (10 kHz) and uses digital techniques. This definition includes, among other things, digital telephone equipment or any device that generates radio fre- quencies for the purpose of perform- ing data-processing functions such as "electronic computations, operations, transformations, recording, filing, sorting, storage, retrieval, or transfer." The Commission notes that computer terminals and peripherals also fall within this definition but that other components and subassemblies do not. Class A devices are further defined as any computing devices that are marketed for use in a commercial, in- dustrial, or business environment. Class B devices are defined to be com- puting devices marketed for use in a residential environment in spite of their potential use in commercial en- vironments. Examples of Class B devices are electronic games, personal computers, calculators, and similar electronic devices marketed to the general public. Temporarily exempt- 184 September 1980 © BYTE Publications Inc Circle 112 on inquiry card. 1HE OASIS REaPEFORQUAUlY AmiCATION SOnWARE Happy customers are fast making Single & Multi- User OASIS recognized as the super system software. BUT. system software is only as good as the applica- tions it runs. And that's where oasis really cooks. Application software developers particularly like OASIS because it lets them blend unique performance features with their own products — in other words, build better software. Security features like User Accounting with Logon, Password and Privilege Level; File and Automatic Record Locking; Private, Shared and Public Files. Speed and convenience of Keyed Index (ISAM) Files. Economy from Compiled Re-Entrant BASIC that makes multi-user systems practical on as little as 64K memory. And lots more. Because oasis has better development tools — and more of them — creating very sophisticated software is possible, practical, easier, faster. Just one example: basic that is an Interpreter and Compiler with Debugger and Editor. If you do your own development, you'll really appreciate these kinds of features. For software professionals, they make providing superior products much more cost attractive. Add all the ingredients (together and, whether you do it yourself or buy it off the shelf, the pay-off is a wide selection of top- performing, top-quality application software that does more so you do less. OASIS; Single or Multi- User with a sizzling array of features and tools; almost unlimited software possibilities (and applica- tion software for Single- User OASIS is Multi-User compatible); the most extensive documentation in the industry — indeed, you get a lot to like. And that's put OASIS System Software* among the hottest products on the market. Drop us a line today for a complete, free Application Software Directory. And see your OASIS Distributor, or send the coupon direct, to get the products you want. Try us. We believe you'll savor the OASIS recipe. * For Z80 based computers. OASIS IS AVAILABLE FOR SYSTEMS: Altos; Compucorp; Cromemco; Delta Products; Digital Group; Digital Microsystems; Dynabyte; Godbout; IBC; Index; Intersystems; North Star; Onyx; SD Systems; TRS 80 Mod II; Vector Graphic; Vorimex. CONTROLLERS: Bell Controls; Cameo; Corvus; Kenan; Micromation; Micropolis; Tarbell; Teletek; Thinkertoys; X Comp. APPLICATION SOFTWARE AVAILABLE FOR OASIS: Accounts Payable; Accounts Receivable; General Ledger; Mail List Pak; Order Entry/ Invenlory Control; Inventory Tracking Pak; Word Processors Architects & Pro Designers Timekeeping & Job Cost Analysis; Cable TV Subscriber Billing Sys; Construction Mgt Pak; Construction Pak; Contractors Tracking Pak; Distributors Pak; Dental Office Mgt Pak; Medical Billing Sys; Pharmacy Prescription Processing with A/R; Management Analysis Pak; Real Estate Office Mgt; Restaurant Pak; Sewer & Water Utility Info Pak. Bisyncronous Communication Pak; 2780/ 3780/3270 Emulators; File & Screen Mgr with Report Generator; Full Network Data Base Mgt Sys; Game Pak; Hierarchical Data Base Mgt Sys; Radlogs (Radio Station Logs/Schedules/Programming/Billing with A/R, A/P, G/L THESE ITEMS ARE NOT AVAILABLE DIRECT FROM PHASE ONE SYSTEMS. INC. —please write for ordering instructions and complete, free Application Software Directory. If you have items you would like listed in the Directory, send us complete information.) MAKES MICROS RUN LIKE MINIS PLEASE SEND ME: Product OPERATING SYSTEM (Includes: EXEC Language; File Management; User Accounting; Device Drivers; Print Spooler; General Text Editor; etc.) SINGLE-USER MULTI-USER BASIC COMPILER/ INTERPRETER/DEBUGGER RE-ENTRANT BASIC COMPILER/INTERPRETER/ DEBUGGER DEVELOPMENT PACKAGE (Macro Assembler; Linkage Editor; Debugger) TEXT EDITOR & SCRIPT PROCESSOR DIAGNOSTIC & CONVERSION UTILITIES (Memory Test; Assembly Language; Converters; File Recovery; Disk Test; File Copy from other OS; etc.) COMMUNICATIONS PACKAGE (Terminal Emulator; File Send & Recet/e) PACKAGE PRICE (All of Above) SINGLE-USER MULTI-USER FILE SORT COBOL-ANSI '74 Price with Manual S150 350 500 850 Manual Only $17.50 17.50 60.00 60.00 Order OASIS from: Phase One Systems, Inc. 7700 Edgewater Drive, Suite 830 Oakland, CA 94621 Telepfione (415) 562-8085 TWX 910-366-7139 NAME.^ STREET (NO BOX #) CITY STAT E 2 1 P AMOUNTS (Attach system description; add S3 for shipping; California residents add sales tax) D Check enclosed D VISA D UPS C.O.D. D Mastercharge Card Number Expiration Date Signature ed (pending further rulemaking by the FCC) from the specific Class B technical and administrative re- quirements are microprocessors utilized in transportation vehicles, home appliances, test equipment, and electronic power or control systems utilized in industrial plants. Compliance Verification Procedures Class A device manufacturers are required, prior to marketing, to verify that their devices meet the technical provisions set forth in the FCC's rules. In contrast, manufac- turers of most Class B devices on the market (eg: electronic video games and personal computers) must certify to the Commission that their devices comply. Herein lies the heavy burden to be shouldered by the personal computing industry under the FCC regulations. (For, if any lesson is to be learned from the FCC's "Part 68 Pro- gram" for certification of telephone devices, it is that federal regulations of this type are both costly and time consuming for manufacturers.) Verification (for commercial de- vices) is basically an approval pro- cedure based on the honor system, whereby a manufacturer tests his equipment to verify to the public that it complies with the appropriate technical standards. Although no FCC notification is imposed, manu- facturers are still required to maintain records of their testing procedures and results. By comparison, certification (for consumer devices) is an arduous equipment-authorization procedure which requires manufacturers to test their product for compliance and sub- mit the test information to the FCC along with a completed application (FCC Form 731), photographs, and fees. After the FCC reviews the submissions, a certification number is issued for the tested equipment; the manufacturer must affix this number to every model thereafter imported, advertised, or marketed. Any subse- quent change in the circuitry or oper- ation requires that the equipment be recertified to the FCC. Due to their high potential for causing RFI, the Commission has de- termined that only the following de- vices must be certified: electronic games, including coin-operated video games (but excluding handheld games that do not use a television (1a) RADIATION - Maximum field-strength limits Frequency (MHz) Distance (meters) Field Strength (/iV/m) Class A 30 to 88 88 to 216 216 to 1000 30 30 30 30 50 70 Class B 30 to 88 88 to 216 216 to 1000 3 3 3 100 150 200 (1b) CONDUCTION - Maximum voltage levels Frequency (MHz) Ma> cimum RF Line Voltage (^V) Class A 0.45 to 1.6 1.6 to 30 1000 3000 Class B 0.45 to 30 250 Table 1: Radiation and conduction standards for computing devices. Table la sets the maximum permissible level of radiated radio-frequency emissions for both Class A (commercial) and Class B (consumer) devices. Table lb does the same for con- ducted emissions impressed on the electrical-power network. receiver for display); personal com- puters (excluding digital clocks, desk- top calculators, and handheld calcu- lators); and peripherals and terminals capable of being attached to a per- sonal computer. All other Class B de- vices need merely be verified by manufacturers prior to their marketing. Technical Standards The technical standards imposed by the new rules are designed to pro- vide a "reasonable degree" of protec- tion for radio and television receiv- ers. Since unwanted interference from computing devices can result from ra- diated as well as conducted RFI, the standards regulate both types of em- mission. (See table 1.) Radiation test- ing requires manufacturers to measure the radio-frequency emana- tions at specified frequencies and distances from their equipment to en- sure that certain maximum energy levels are not exceeded. Conduction testing is designed to ensure that equipment will not impart more than a maximum level of energy over a specified frequency range into the electrical-power network. [For exam- ple, this restriction will apply to devices that use house wiring to remotely control appliances.... GW] (The actual equipment-test proce- dures to be used by manufacturers are the subject of a current rule- making before the FCC. Until final rules are issued, the Commission has approved certain conventional indus- try test procedures.) Together, both tests protect against interference frequencies as low as 450 kHz (just below AM radio) to fre- quencies as high as 1000 MHz (above UHF television signals). As stated previously, the standards for Class B equipment are ten times more strin- gent than those for Class A. Labeling and User Information Complex rules notifying users of their computing devices' potential (or lack thereof) for interference with radio communications and spelling out corrective action to be taken are key aspects of the FCC's administra- tive regulations. In essence, all com- puting devices will require some type of labeling or warning after January 1, 1981; however, these regulations will vary depending on the classifica- tion of the device as well as the device's mandatory-compliance date. All Class A equipment (unless cer- tified under the Class B standards) must warn users that its operation in a residential environment may cause interference for which the user will be held accountable. 186 Seplember 1980 © BYTE Publications Inc TERRIHC TRIO: ZSaOASISwMAROT. A superior operating system and top application software bring out the best in a nnicrocomputer. That's why Marot offers the oasis* Operating System and compatible software for owners of Z80 based micros. They make a terrific trio. 1Z80 MICROS —great machines. Tandy's trs-80 MOD ir with DMA, bank select possibilities and nationwide service. Altos. Cromemco. Horizon. And many others. Great machines — but it takes a great operating system to tap their full potential. 2 ENTER OASIS —available from Marot. oasis is fast emerging as ^^e operating system for Z80 commercial applications and serious programmers. Why?. ..rapid formating and back-up of diskettes; efficient disk utili- zation; excellent line editor and document processor for file management and textwriting; user accounting with logon, password, privi- lege level and use account- ing; machine independence of programs, data and text files; sequential, direct and keyed index (isam) files; interpreted and compiled BASIC; COBOL-ANSI 74; single and multi-user ver- sions; and more. No wonder pros say 'oasis makes micros run like minis!' 3 APPLICATION SOFTWARE — available from Marot. OASIS is your active, invisible partner supporting these excellent, ready-to-run products: Magic Wand ." The word processor combining the ease of screen editing with micro power. HDBS ** For data management needs restricted to hierarchical tree structure and fixed length records. MDBS ** Handles full network CODASYL oriented data structures and variable length records. ABS*** Quality office management systems — accounts receivable and payable, general ledger, etc. — the total interacting, user-oriented business package. Written in COBOL; available with source code. A Law package. And ready soon: complete medical management, real estate, restaurant, pharmacy management analysis packages, and others. Marot and its Dealers offer OASIS and many professional software products to individuals, OEMs and dealers. Licensing arrangements are also available. Just call or write and start your own terrific trio. (Circle what you would like and send order with payment to the address shown below.) PLEASE SEND ME: Product OASIS □ SEND COMPLETE INFORMATION Product MAGIC WAND Price $400 ABS ACCOUNTING (call or write) MDBS, full network MDBS Report Generator, Query System Primer (Other options available) $900 300 300 10 Magic Wand, MDBS and MDBS are available for several operating systems. 'OASIS I s ihe trademark o f Ptiase One Systems, Inc "HOBS and MDBS are produced by Micro Data Base Systems. Inc ""American Business Systems, tnc TRS-80 IS ttie registered trademark of ihe Tandy Corporation MagiC Wand is the registered tirademark of Small Business Systems. Inc OPERATING SYSTEM (Includes: EXEC Language; File fvlanagement; User Accounting; Device Drivers; Print Spooler; General Text Editor; etc.) SINGLE-USER fvlULTI-USER MAROT SOFTWARE SYSTEMS YOUR EASTERN SOURCE BASIC COMPILER/ INTERPRETER/DEBUGGER RE-ENTRANT BASIC COMPILER/INTERPRETER/ DEBUGGER DEVELOPMENT PACKAGE {f^acro Assembler; Linkage Editor; Debugger) TEXT EDITOR & SCRIPT PROCESSOR DIAGNOSTrC& CONVERSION UTILITIES (fvlemofy Test; Assembly Language; Converters; File Recovery; Disk Test; File Copy from other OS; etc.) COMMUNICATIONS PACKAGE (Terminal Emulator; File Send & Receive) PACKAGE PRICE (All of Above) SINGLE-USER MULTI-USER FILE SORT COBOL-ANSI 74 Price with Manual S150 350 500 850 Manual Only $17,50 17.50 60.00 60.00 Send ortder to: Marot Software Systems, Inc. 35 East 85th Street New York City, NY 10028 Telephone (212) 534-5499 NAME. RTRFFT (NO RHY *) niTY ?;tatf 7IP AMOUNTS (Attach system description; add $3 for shipping; New York residents add sales tax.) □ Check enclosed □ VISA D UPS COD. D Mastercharge Card Number __^__ Expiration Date Signature Circle 113 on inquiry card. BYTE September 1980 187 Mandatory-Compliance Dates With regard to the new rules' effec- tive dates, here too, the Com- mission's regulations are complicated and confusing. Originally, the Com- mission proposed a single deadline, July 1, 1980, after which all manufac- turers of computing devices would have to comply with the appropriate rules or cease marketing their equip- ment. However, it soon became ob- vious to the Commission that several factors made a unified effective date impractical; these factors include the apparent lack of trained personnel to perform the necessary tests, the large number of devices in production that would have to be tested, and the shortage of emission-suppression components. Upon reconsideration, therefore, the FCC adopted the following schedule of mandatory effective dates for compliance with its Part 15 rules (see table 2): Personal computers and other devices requiring certification (eg: video games, peripherals, and terminals) must meet the Class B standards by January 1, 1981. All other computing devices (Classes A and B) must comply with the appropriate device stan- dards if first manufactured after October 1, 1981. If such (noncertificated) devices, however, are placed into produc- tion before October 1, 1981, compliance will not be required (for subsequently produced devices) until October 1, 1983. Any device failing to meet these mandatory-compliance dates cannot lawfully be marketed, imported, or advertised for sale in the United States. Special Rules for Subassemblies and Peripherals Components and subassemblies of computing devices are not required to comply independently with the Com- mission's technical standards. In ad- dition, peripherals supplied as part of a computing device do not need to be considered separately. Nevertheless, because all end products must com- ply, systems vendors and integrators can be expected to pressure their com- ponents suppliers into indirect com- pliance with these new rules. On the other hand, peripherals marketed independently from their associated computing devices must comply directly with all technical and administrative standards. Peripherals marketed as part of any personal computing systems (which are in the Class B certified category) therefore must be certificated; all other peripherals (in the Class B noncer- tified and Class A categories) need merely be verified. In addition, peripherals sold separately from their computing systems also must be in- dividually labeled. Enforcement of Computing Device Rules Lest there be any question as to the Commission's experience or commit- ment in enforcing its interference regulations as they pertain to the mass distribution of consumer de- vices, you need only recall the regula- Compljance Date January 1, 1981 October 1. 1981 October 1, 1983 Equipment Class All Class B devices requiring certification (personal com- puters, electronic video games, and peripherals and ter- minals capable of being attached to personal computers) manufactured after this date. All Class A devices and Class B devices not requiring cer- tification which are first placed into production after this date. All Class A devices and Class B devices not requiring cer- tification which are manufactured after this date, regardless of when first placed into production. Any device failing to meet these mandatory compliance dates cannot lawfully be marketed, imported, or advertised for sale in the US. Table 2: Dates of mandatory compliance for computing devices. 188 September 1980 © BYTE Publications Inc Hazeltine Distributors: ALABAMA: Huntsvllle. W A Brown Instruments. Inc (205) BB3-B660 ALASKA: Anchorage. Global Communications. Inc. (907) 276-4532. ARIZONA: Phoenix, Data Systems Marketing (602) 265-5216. Leasametnc (602) 258-1225: PLS Associates, Inc. (602) 279-1531; Tempe. Hamilton Avnet Electronics (602) 275-7851 ; The Phoenix Group (602) 894-9247. CALIFORNIA: Anaheim. Leasametric (714) 634-9525: Burlingame. Data Access Systems (415) 692-5711; Carson. Data Access Systems (213) 538-4100: Data Systems Marketing (213) 324-1 151 ; Costa Mesa. Hamil- ton Avnet Electronics (714) 641 -4100; Avnet Electronics (714) 754-61 11: Culver City. Hamilton Avnel Electronics (213) 558-2000; Leasametric (213) 670-0461: Foster Clly. Leasametric (415) 574-4441; Hawthorne. Hamilton Avnet Electronics (213) 970-0956; Hayward, Byte Industries. Inc. (415) 783-8272; The Phoenix Group (415) 887-2851 ; Irvine. Compu- ter Datacom, Inc. (714) 540-6327; Data Systems Marketing (714) 540- 2312; Kentfleld, American Permheral Exchange (415) 457-0822: Los Angeles, David Jamison Carlyle Corp (213) 277-4562; Martinez, Ameri- can Peripheral Exchange (415) 229-3810. Mounlainviaw, Data Syslems Marketing (415) 941-0240. Newport Beach, Davtd Jamison Carlyle Corp (714) 640-0355; Northrldge, Day on-Forester Associates. Inc (213) 992- 8831; Oakland, Consolidated Data Terminals (415) 533-8125; Orlnda, David Jamison Carlyle Corp (415) 254-9378: Redondo Beach, Consoli- dated Data Terminal (213) 970-1030: San Diego. Data Syslems Marketing (714) 560-9222: Electronic Marketing Specialists (714) 560-5133. Hamil- ton Avnet Electronics (714) 571 -7510: Leasametnc (714) 565-7475. Santa Clara, American Peripheral Exchange (408) 244-0260: Sherman Oaks, Electronic Marketing Specialists (213) 990-4244; Sunnyvale, Electronic Marketing Specialists (408) 245-9291; Hamilton Avnet tiectronics (408) 743-3355: TorrancB. The Phoenix Group. Inc. (513) 533-8134. Justin. Electronic Marketing Specialists (714)832-9920. COLORADO: Denver, Data Systems Markeling (303)573-5133; Leasame- tric (303) 429-7900; PLS Associates, Inc. (303) 773-1216; Englewood, Hamilton Avnet Electronics (303) 779-9998. CONNECTICUT: West Haven, Westwood Associates (203) 932-6383. Southbury, J. J. Wild, Inc. (203) 264-9494. DELAWARE: Newark, Westwood Associates (302) 454- 1113. FLORIDA: Fort Lauderdale, Hamilton Avnet Electronics (305) 971-2900; W. A Brown Instruments. Inc. (305) 776-4800: Melbourne, W. A Brown Instruments, Inc (305)723-0766; Orlando, Leasametric (305) 857-3500. W.A.Brown Instruments, Inc. (305)425-5505; Tallahessea, W, A. Brown Instruments, Inc. (904) 878-6642; Tampa, W. A. Brawn Instruments. Inc. (813)977-0914. GEORGIA: Atlanta, Data Access Systems (404) 449-5435; W. A Brown Instruments, Inc. (404) 455-1035: Lake City, Westwood Associates (404) 961-0712: Norcross, Hamilton Avnet Electronics (404) 448-0800; Leasa- metric(404) 449-6123. HAWAII: Honolulu, David Jamison Carlyle Corporation (808) 531-5136: Kaneoke. Data Systems Marketing (808) 247-0934. ILLINOIS: Chicago. David Jamison Carlyle Corporation (312) 475-1500: Elk Grove Village. Leasametric (312) 595-2700; Peripheral Support Inc. (312) 593-5900; Morton Grove. Data Access Systems (312) 967-0440; Schiller Part, HamiltonAvnet Electronics (312) 676-6310 INDIANA: Indianapolis, Hamilton Avnet Electronics (317) 844-9333; South Bend. General Micro Computer (219) 277-4972. KANSAS: Lenexa. North Supply Company (913) 888-9800: Loonam Asso- ciates, Inc. (913) 888-2124; Overland Parte, Hamilton Avnet Electronics (913) 888-8900: Shawnee Mission. Inland Associates. Inc. (913) 362- 2366. KENTUCKY: Jeftersontown. Loonam Associates (502) 499-8280. LOUISIANA: Mandevllle, W. A Brown Instruments, Inc. (504) 626-9701 MARYLAND: Baltimore. Hamilton Avnet Electronics (301) 796-5000. Westwood Associates (301) 358-7812: Galthersburg. Leasametric (301) 948-9700: Lanham, Data Access Systems (301) 459-3377. MASSACHUSEHS: Cambridge, Compumart Corporation (617)491-2700; Needham. J. J. Wild, Inc. (617) 444-2366: Norwood, Data Access Sys- tems (617) 769-6420; Wobum. Hamilton Avnet Electronics (617) 273- 7500: Leasametric (617) 935-7780. MICHIGAN: AnnArbor. Compumait Corporation (313) 994-3200: Livonia. Hamilton Avnet Electronics (313) 522-4700: Troy. Data Access Systems (313)589-1409 MINNESOTA: Bumsvllle. Leasametric (612) 894-6060: Edina. Hamilton Avnet Electronics (612) 941-3801; Minneapolis. Loonam Associates (612) 831-1616. MISSOURI: Earth City, Hamilton Avnet Electronics (314) 344-1200: SL Louis, Inland Associates (314) 821-3742: Loonam Associates (314) 427- 7272. NEBRASKA: Omaha. Loonam Associates (402) 333-5502. NEW HAMPSHIRE: Merrimack, J. J. Wild. Inc. (603) 424-4717 NEW JERSEY: Allsndale. Leasametric (201) 825-9000: Bogota. Qytel (201)487-7737; ChanyHltl. The Datastore. Inc. (609)779-0200. Hamil- ton Avnet Electronics (609) 424-0100; CInnamlnson. Westwood Associ- ates (609) 829-7280: Fairfield, Hamilton Avnet Electronics (201) 575- 3390; Matawan, David Jamison Carlyle Corporation (201) 946-9669: Mountain Lakes, Data Access Systems (201) 335-3322: Palisades Park, Data Access Systems (201) 944-2005: Roselle, TSC Data Terminals (201) 245-6333: Springfield. Westwood Associates (201) 376-4242: Union. Transnet Corporation (201) 688-7800. NEW MEXICO: AlbuquerflUB, Data Systems Marketing (505) 294-5790; PLS Assocales. Inc. (505) 255-2330 NEW YORK: Falrport. Data Access Systems (716) 377-2080: Great Neck. MTI Sales Corporation (212) 896-7177; Hollls. Synchro-Sound Enter- pnses (21 2) 466-7057; Latham. J. Cameron Associates. Inc. (518) 371- 5947; Melville. Hamilton Avnet Electronics (516) 454-6060: New York. Byte Shop East. Inc. (212) 889-4204; Data Access Systems (212) 564- 930 1; Leasametric (212) 594-6900; John D Owens Associates, Inc (212) 448-6283; Qytel (212) 889-3888: PIttslord, J. Cameron Associates, Inc (716) 386-1681: Plalnwlew. Leasametric (516) 293-5881; Rochester, Hamilton Avnet Electronics (716) 475-9130: East Syracuse, HamiltonAv- net Electronics (315) 437-2641 ; Syracuse. Leasametric (315) 455-561 1 NORTH CAROLINA: Durham, W. A. Brown Instruments. Inc (919) 683- 1580. OHIO: Cincinnati, Interactive Information Systems (513) 761-0132; Cleve- land, Data Access Systems (216) 473-2131; HamiltonAvnet Electronics (216) 831-3500; MTI Systems (216) 464-6688. Pro-Data CorpDralon (216) 229-8100; Dayton, Hamilton Avnet Electronics (513) 433-0610; Leasametric (513) 898-1707. OREGON: B end. Data Systems Marketing (503) 388-3612; Hlllsboro, Data Syslems M arketing (503) 640-4883, PENNSYLVANIA: Aston, MLPI Newcorp Products. Inc. (215) 485-8180, Bala Cynwyd, Data Access Syslems (215) 667-8315; Folcroft. Leasame- tric (215) 583-200 0; Huntingdon Valley, Marketltne Systems, Inc. (215) 947-6670. SOUTH CAROLINA: Columbia. W A Brown Instruments. Inc (803) 798- 8070. TENNESSEE: Oak Ridge, W, A. Brown Instruments. Inc. (615) 482-5761 TEXAS: Austin, Hamilton Avnet Electronics (512) 837-8911; Dallas, Leasametric (214) 661-9193; Houston. CMC Marketing Corporation (713) 995-4960; Data Access Systems (713) 682-5965; Hamilton Avnet Elec- tronics (713) 780-1771; Leasametric (713) 977-5990; Irving, Data Access Systems (214) 256-5536; Hamilton Avnet Electronics (214) 661-8204. UTAH: Salt Lake Clly, Data Systems Marketing (801) 467-8281; Ha mUon Avnet Electronics (801) 972-2800; PLS Associates. Inc. (801)466-8729. VIRGINIA: Newport News. Atlantic Communications (804) 380-8498; Sterling. Comsel Corporation (703) 525-5889: Vienna, Comsel Corpora- tion (703) 938-5264. WASHINGTON: Bellevue, Hamilton Avnet Electronics (206) 643-3950; Bothell, Data Systems Marketing (206) 487-3571; Redmond, Consoli- dated Data Terminals (206) 883-0100; Leasametric (206) 883-6510; Tukwila, Data AccessSystems (206) 251 -5070 WISCONSIN: Milwaukee, Hamilton Avnet Elect onics (414) 784-4510; Pe- ripheral Support, Inc. (414) 774-1000: Waukesha. Loonam Associates (414)548-9790. Smart shopping Your Hazeltine distributor has all the terminals you need. You can save time by taking all your TTY terminal needs to one source —your local Hazeltine distributor. Right in your neighborhood, your distributor offers the same quality, the same service and the same comprehensive warranty program that you would get by contacting Hazeltine directly. ^ The Hazeltine distributor can give you easy ^^ ' -^ -^ ■ access to a broad selection of Hazeltine products, including the economical Hazeltine 1400/1500 series of conversational and editing terminals, the high performance Modular One family, and — soon — the new Hazeltine Executive 80^" line , ,. of sophisticated smart terminals. [v^^ : An experienced sales professional, your local distributor is ready to provide full product and application support. Most important, each of our autho- rized distributors has Hazeltine's full support. You will find that Hazeltine's entire field and factory organization supports the distributor when you need delivery, warranty service, or even just the answer to a question. Be a smart shopper. Call your near- est Hazeltine distributor— part of our winning team forthe eighties. Hazeltine Corporation, Computer Terminal Equipment, Greenlawn, NY 11740. (516) 549-8800 Telex: 96-1435 Hazeltine and the Pursuit of Excellence Answers for the Eighties Hazeltiri 1500Seri Utti« M h^'Km^-^^' Circle 114 on inquiry card. BYTE Seplember 1980 189 tory crackdown that accompanied the Citizens Band radio craze of a few years ago. There, the Commission revealed that it had adequate power over both manufacturers and retailers to prevent users from gaining access to equipment that was improperly engineered or tested. The FCC can enforce its rules through either civil or criminal pro- ceedings. For simple violations of any rules, the FCC has the power to issue cease-and-desist orders (ie: adminis- trative injunctions) commanding the violator to comply with the rules or possibly face severe consequences. The severe consequences may be in the form of court-ordered injimctions or, in the case of willful violations, felony prosecutions with possible fines and prison terms of up to 2 years. Needless to say, criminal sanc- tions are rarely imposed by the Com- mission. The FCC is hoping, rather, for manufacturers and vendors to com- ply willingly with its rules to avoid developing a reputation for selling customer equipment that results in widespread interference. Should large-scale noncompliance result, however, more vigorous standards and more troublesome equipment-au- thorization procedures could very likely be adopted by the Commission and imposed on the entire industry. Conclusion As with any FCC rulemaking that involves evolutionary consumer pro- ducts, the Commission's activities to date may reveal only the tip of the iceberg. The protracted FCC proceed- ings involving telephone-equipment registration bear strong witness to this observation. New microproces- sor-based devices may create unfore- seen RFI problems not addressed in the new rules, changing work pat- terns will slowly blur the environ- mental distinctions between the home and office, and evolving communica- tion services will continue to place additional demands on spectrum usage. Indeed, the Commission's fun- damental assumption for its classifi- cation of computing devices (ie: prox- imity to RF receivers) is already start- ing to erode as radio receivers become increasingly utilized in commercial environments for the provision of Teletext and direct (rooftop) broad- cast satellite services. With new rules come new costs — whether they be costs of equipment redesign, costs of RFI-suppression components, or costs of testing, label- ing, and FCC-certification delays. The FCC is currently in the midst of a rulemaking proceeding to develop the Part 15 equipment-testing procedures. Slated for possible future rule amendments are handheld calculators, home appliances, microprocessor-based transportation systems, and other similar devices. Manufacturers of these types of equipment, therefore, should adapt to the idea that the FCC represents a cost of doing business that cannot be avoided — from now on. Incidentally, the FCC's rules seek only to prevent interference between computing devices and (FCC- approved) communications services. Interference between incompatible devices utilized in the home (eg: wireless intercoms, burglar- and fire- detection systems, wireless switches, etc) is probably beyond the FCC's jurisdiction. Thus, it will be up to the industry itself to resolve among its own members — possibly through the newly-formed Home Bus Standards Association — these emerging in- terference issues. ■ Okidata Microline 80 . . $547 912 B 912 C Televideo $698 920 B . $698 920 c $748 $748 Texas Instruments 810 $1,498 Zenith z-19 $826 z-89 $2,437 Atari 800 . $748 .400 . $445 Texas Instruments 99/4 Console $698 99/4 Color Monitor . $350 (when purchased w/ console . $200) Scotch - 5%" 1 sector S/S D/D Qty. 10 . . . $29 Verbatim - sv^" io sector d/s d/d Qty. io . $38 Novation -Cat $148 Soroc - IQ 120 $696 Parkin Elmer - Bantam $696 Mattel - Intellivision $238 We will try to beat any advertised prices! We Also Buy and Sell Used Micro Computers & Peripherals. Product shipped infactorycartons with manufactures warranty. Add 2%, a minimum of $5, for shipping and handling. [^^^ 602-954-6I09 ■ 2222 E. Indian School Rd. • Phoenix, Arizona 85016 Prices & availability subject to change without notice. COmPUTER UJAREHOUSE 190 September 1980 © BYTE Publications Inc Circle 115 on inquiry card. -v^A W ^ Solv dP^ "WordPro is the most sophisticated Word Processing Software package available for the Commodore Computer line," Solve Your Paperwork Problem. . . Let WordPro Software Do The Work Using standard typing methods, hundreds of valuable hours are spent erasing, revising, and retyping letters and documents as you work towards a final draft copy. The second, third, or fourth drafts take just as long to type as the first! With WordPro word processing software you can transform your Commodore computer into a "state of the art" word processing machine with sophisticated word processing features at an affordable price. There are four versions of WordPro, ranging from the simple to the sophisticated. WordPro 1 on cassette will give computer enthusiasts a full range of textediting capabilities with cassette file storage. WordPro 2isdisk based and allows fast and easy filehandling and manipulation. WordPro 3 was designed for professionals and contains the many features required in a business environment sue has global search and replace, headers, footers, decimal tabulation, repagination, merging capabilities, and much, much more. WordPro 4 is our best. WordPro 4 runs on the new Commodore 8032, 80-column display computer. WordPro 4 has all the features of WordPro 3, plus additional features usually found only on the most sophisticated and expensive word processing equipment. WordPro is a new breed of word processing software. Powerful, sophisticated, and easy to use, WordProwasfield-tested by dozens of attorneys and commercial customers during 1979. WordPro is now installed and is saving its owners valuable time and money in hundreds of offices nationwide. WordPro was designed with the user in mind. WordPro's unique "STATUS LINE" constantly interacts with the user by displaying the status of the system. Editing, storing documents, recalling letters, even the most sophisticated comands, are accomplished by a few, easy to remember, keystrokes. You may find that WordPro alone is reason enough to own a computer. Word Pro can be found at most Commodore dealers worldwide. Call us for the number of the dealer nearest you. If you cannot locate a stocking WordPro dealer you may place an order with Professional Software via check or VISA/MasterCharge. All Actual Photograph of WordPro on CBM Model 8032 The many features of WordPro 1 - 4: WordPro 1 - Cassette based • Status line • Test Editing • Insert/Delete • Screen Scroll Auto Repeat • String Search • Erase Functions • Link Files • Margin Controls • Tab Functions* Justification • Page Length WordPro 2 - Most WordPro 1 Functions Plus + Disk Based • Paragraph Indent* Centering • TextTransfer* Hyphenation • Appending • Margin Release • Variable Blocks (Form Letters) • Multiple Copies • Automatic Disk Commands • Complete Disk File Handling WordPro 3 - Commercial Disk Version for 40 Columns • WordPro 2 Functions Plus + Global Functions (Search/ Replace/Copy)* Merging Disk File Linkage* lOor 12 Pitch* Repagination • Duplicate Lines • Auto Delete Word/Sen- tence/Range • Numeric Mode • Underlining • Continuous Print • Headers/Footers • Auto Page Numbering • Pro- portional Justification • Forced Paging • Non-Print Com- ments • BASIC Language File Compatibility WordPro 4 - Commercial Disk Version for 80 Columns • WordPro 3 Functions Plus + Displays and Formats Text to Screen for Review WordPro 1 — For all 8K RAM units. Requires C2N Peripheral/integrated cassette drive - $29.95 WordPro 2 — For all 16K RAM units with 40 column screen. Requires 2040 disk drive - $99.95 WordPro 3 — For all 32K RAM units with 40 column screen. Requires 2040 disk drive - $199.95 WordPro 4 — For Model 8032 with 80 column screen. Requires 2040 or 8050 disk drive - $299.95 four versions of WordPro are written In 6502 machine code. Professional Software Inc. 166 Crescent Rd., Needham, MA 02194 (617)444-5224 Circle 116 on inquiry card. *WordPro Dealer Inquires Invited* WordPro was developed by Steve Punter of Pro-MicroSoftwareLtd., and is marketed exclusively by Professional Software Inc. WordPro Is a registered trademark of Professional Software Inc. CBM Is a registered trademark of Commodore Business Machines. BYTE Seplember 1980 191 BUY ONE of these great professional books when you join the mi mlcfocdmputer ok MINICOMPUTER SYSTEMS, Organiza- tion, Programming, and Applications. By Richard H. Eckhouse, Jr. and L. Robert Morris. 2nd Ed., 491 pp., illus. Updated, re- vised, and expanded, this is a book for every systems programmer, systems designer, computer scientist, and application specialist who wants to know more about microcomputer hardware, software, and design. 787 /026 Pub Pr., S21.95 Club Pr., S17.75 MICROELECTRONICS: Digital and Analog Circuits and Systems. By Jacob Millman. 807 pp., 700 illus. Exciting news for the thousands of engineers who want a thor- ough refresher and updating on today's ICs. Will be welcomed by both digital and analog electronics engineers at every level of profi- ciency 423/27X Pub. Pr., S28.95 Club Pr., $22.50 AUTOMATIC DATA PROCESSING HANDBOOK. Edited by The Diebold Group. 976 pp., 269 illus. 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Corporate Aftltiation Ttiis order subject la occeptance by McGraw-Hill All prices subject to change wittiout notice er good only la new members A postage and handling charge is added to all I shipments P39475 I lecrCKHcsl Fcpixn Relocating Assemblers and Linking Loaders Ottmar E Bochardt, 4560 Decade #301, Montreal PQ H3X 2H6, Canada Relocating assemblers and linking loaders are two pieces of assembly-language-oriented software that are probably unfamiliar to the average computer enthusiast. As a matter of fact, the very words relocating and linking (especially the latter) sometimes conjure up ideas of some vague, unspecified process. In reality, though, relocating assemblers and linking loaders are companion pieces of software that are easy to understand. The purposes of this Technical Forum are to: • explain the relocating and linking processes; • compare the two major linking methods; • demonstrate how the assembly process is made slightly more complicated by relocating and linking; • comment on the microprocessor-software standard proposed by Formaniak and Leitch. My machine-language examples are all based on the MOS Technology 6502 processor. The Technical Forum "A Proposed Microprocessor Software Standard" by Peter Formaniak and David Leitch appeared on page 34 of the July 1977 BYTE. Relocating and Linking Process A relocating assembler is one which assumes that your program will be stored beginning at location zero in memory. In addition to object-module records that give the assembled machine-language code, the relocating assembler also generates extra information in relocation records to indicate which parts of the object module must be changed if the code is loaded beginning at some loca- tion other than zero. A relocating loader, then, need only be slightly more intelligent than an ordinary (or absolute) loader. It must be able to: • separate the input stream into individual object modules; • assign a relocation address to each module; WHY CANT MICROPOLIS DO THINGS LIKE EVERYONE ELSE? 194 September 1980 © BYTE Publications Inc Listing 1: Example output from a relocating assembler. The code followed by tlie symbol R indicates a relative address, one that will be changed if this code is relocated to any starting location other than hexadecimal 0000. The code followed by the symbol G or G' indicates an external address, one that will have a known value only when this module is linked with other modules of code. Hexadecimal Hexadecimal Address Code Label OOOOR OOOOR OOOOR OOOOR OOOOR OOOOR C3 70 OOR A2 00 SUBl Instruction Mnemonic Operand .ENTRY .EXTRN .EXTRN .EXTRN LDA LDX SUBl SUB2 COMMON 1 VALOOl COUNT §0 Commentary declare SUBl to be an internal symbol 0040R 004 IR CA D4 00 01 LOOP DEX STA DATA 004DR 004FR 0052R 0055R AOOOG' BD OC OOG 20 00 OOG 4C 40 OOR LDY #VAL001 LDA COMMONl + 12,X JSR SUB2 IMP LOOP 0070R IE COUNT .BYTE $1E 009CR 60 RTS 0000 .ASECT 0100 * = $100 0100 00 03 07 DATA .BYTE OOOOR .END deposit some absolute code 0,3,7 SUBl To be honest we could. But our customers have come to expect a lot more from us. They've come to appreciate our desire to innovate, to improve upon, to blaze new trails in floppy disk technology That's how we got our reputation as the industry's undisputed tech- nological leader; 96 TPI is nothing new for us. Consider the current hubbub about "new" 95 TPI disk drives. You should know that what may be new to our competition is anything but new to us. After all, we brought the 100 TPI MegaFloppy™ disk drive to the marketplace more than two years ago. And we've delivered more than 50,000 drives already To us, a 95 TPI drive is no big deal. So for the customer who's looking for a double track drive offering compatibility with 48 TPI drives, Micropolis can deliver Think of us as double headquarters. We should also mention that our double track disk drives give you all the storage capacity of an 8-inch floppy in the body of a 5y4-inch floppy And with our double head version, you get up to 1.2 megabytes. That's more than ten times the capacity of other 574 -inch floppies. But our innovations don't stop there. Over the years, many of our ideas have gone on to become industry standard. And many more will. Things like stainless steel, precision-ground lead screws instead of cheaper less reliable plastic positioners. We also developed a special disk centering mechanism that is the most accurate in the industry. And who do you think successfully adapted Group Code Recording technology to the floppy disk drive industry? None other than Micropolis. Remarkable as our technical achievements may be, some people still wonder how we got to be number two so rapidly in such a fiercely competitive business. Obviously we did it by design. MICROPOLIS" Where the 5V4-inch OEM drive grew up. Micrcpohs Corporation. 21329 Nordhoff Street, Chatsworth. CA 91511 For the telephone number of your nearest OEM rep, call (213) 709-3500 September 1980 © BYTE Publications Inc 195 NEBSk COMPUTER FORMS KIT EACH KIT CONTAINS: Samples, Prices, Order Form, 4 Checks, 2 Statements, 2 Invoices, Programming Guides. We specialize in small quantities, low prices. 500 CHECKS ONLY $29.95 SEND COUPON, CIRCLE BINGO or PHONE TOLL FREE 1+800-225-9540 FAST SERVICE — it is our policy to ship within 6 working days following our receipt of your order. CODE 459 Name. Address _ City State, Zip NEW ENGLAND BUSINESS SERVICE, INC. GROTON, MASS. 01450 • load each object module in correct relation to the new beginning address; • read the relocation records to determine which memory locations must be changed to point to correct locations within the relocated code. The example given in listing 1, which is source code to be processed by a hypothetical relocating assembler, will help illustrate these functions. Suppose that the object module is to be loaded at hexa- decimal location QibOiQi, The effect of changing the load point of each object module by adding the relocation address shows that all relative addresses (those marked by an R in column 5 of the address) are offset by the amount hexadecimal bQQ) ie: hexadecimal bOO is added to each of these addresses. Certain addresses within a portion of code are referred to in the code itself. If the code is moved (or relocated) to a different location, all references to these addresses (which are called relative addresses) must be changed so as to point to the correct location within the newly relocated code. Specifically, if the relocatable machine code is written to begin at memory location ^^^^, all references to a relative address must be replaced by the sum of the original address plus the relocation offset (which is equal to the beginning address of the code in its new location). An example of this is the JMP LOOP instruction at hexadecimal location ^^bb in listing 1. When the code is written to begin at hexadecimal location QQQQi, the label LOOP refers to memory location 0040. However, when this code is relocated to location ObOO, LOOP becomes location 0540, and the JMP LOOP instruction now at ^bbb is 4C 40 ^b (4C is the JMP op code, and 40 Ob is the address 0540, as stored in the computer, low byte first). In the example of listing 1, all data flagged with an R will be incremented by ObOO. (Note, however, that a relative address is not to be confused with assembly-language relative addressing. The latter refers to a mode of addressing available in the instruction sets of most microprocessors, where the byte being addressed is specified by how far away that byte is from the beginning of the next instruction. A relative ad- dressing displacement byte is usually limited to a signed, one-byte quantity. A relative address, as part of a relocatable object module, is a two-byte address (for all 8-bit microcomputers) that must be changed when the module is relocated to another beginning address.) An absolute address is an address that is not modified during the relocation process because it refers to a por- tion of memory outside the area being relocated. In our example of listing 1, the three bytes at 0100 are designated as being absolute (because they follow the .ASECT or absolute section pseudo-operation). When this section of code is relocated to hexadecimal ObOO, the data bytes will still be at 0100. Thus, the reference to DATA (in the STA DATA line) still points to location 0100. This is because the data at 0100 has not been relocated. Often assembly-language modules are written separately and are meant to be combined at a later time. In many cases, these modules reference each other. A label used in one program but defined in another is called 196 September 1980 © BYTE Publications Inc Circle 117 on inquiry card. OMEGA SALES CO. 44 TRS-80 /^odel II • $3,500 Apple II 16K-$1049 nnTERTEC SGPERBRAIM 32K RAM ■ $2449.00 64K RAM ■ $2649.00 WHOLESALE COMPUTER PRICES" DIRECT TO THE PUBLIC 1 2 Meeting St., Cumberland, R.I. 02864 PRODUCT SPECIAL OF THE MONTH!! iiiiiiiiimmuHimm iiiuuiiiu\iw\\\\\\\\\\\\ \ imiii vm ' 1 Atari 800 $749.00 Products are NOW IN STOCK AT OMEGA Sales Co. [-or: IkS-80. .Applr. CliM. (Intt-dtice Included) Epson TX-80 - $745 ^^^^'^'v!^'^^'^ NEC Spinwriter 5510-5530 -$2449 Soroc 120 -$699 CALL TOLL FREE FOR OMEGA'S PRICE! HMEGA OFFERS THE BEST DELIVERY AND PRICE ON: APPLE • ATARI • TRS-80 MODEL II • INTERTEC • T.I. 810 • HEWLETr-PACKARD-85 • SOROC • COMMODORE * NEC • QGME • CENTRONICS f IMEGA sells only factory fresh, top quality merchandise to our customers. riMEGA will try to match any current advertised price with similar purchase conditions. Before you buy anywhere else - be sure to call HMEGA Sales Co. 1-401-722-1027 or 1-800-556-7587 Circle 118 on OMEGA ships via GPS, truck, or air. COD's, VISA, Mastercharge accepted. inquiry card. I VfSA an external sx/mbol. When the modules are combined into one program, not only must they be relocated to separate memory areas, but they must also be linked; ie: the relocated values of each of the external symbols must be known by all of the modules. This means that the exter- nal symbols must be declared as such within the assembly-language source file. In the sample program of listing 1, the purpose of the .ENTRY pseudo-operation is to declare that the value of the label SUBl (ie: the address of the routine's entry point) is to be made available to other assembly modules. The character string "SUBl" and its value will be in- cluded in the object module, as part of an internal sx/mbol record . The next three statements indicate that the symbols SUB2, COMMONl, and VALOOl are referenced but not defined by this module (they will be defined later, when the modules are linked). These external symbols must be defined as internal symbols by exactly one of the assembly modules present at linking time. All listing lines flagged with a G or G' have an associated entry in an external sx/mbol record, which includes the label name and a pointer to the label's use within the module. For example, the load module used with the module in listing 1 will have an external symbol record that associates the symbol "SUB2" with the address 0053R. Implementing the Link Process As an example, let us look at the format of object modules (ie: the machine-language module created by assembling a source module) resulting from the Mostek SDB-80 assembler. (A description of this standard is given by Formaniak and Leitch. See references.) For each external symbol found, only one object record is produced. All references to a given symbol are linked together with the external-symbol record containing the address of the head of the list and the last entry in the list containing the hexadecimal value FFFF. (See figure 1.) In other words, when the SDB-80 assembler encounters an external reference, it uses that two-byte memory location to indicate to the loader where to find the previous reference to that symbol. In terms of object-file size, this is probably the most efficient way to store linkage information, because it guarantees that only one external-symbol record per symbol will be used, regardless of how many times the symbol is referenced. It follows that, since the number of records being processed is smaller because of the link pro- cess, the time taken to link a series of object files will be minimized. In the case of assembler source code (especially when written for a 6502 or similar processor), this linkage technique has several drawbacks. First of all, there is no provision for handling single-byte values, because two bytes of memory are required within the object code for the pointers. This is a serious deficiency for machines like the MOS Technology 6502 and the Motorola 6800, because these processors allow heavy use of page-zero addressing; in this manner the user can specify an address with one byte. Also, it is convenient to define small- valued parameters externally (such as VALOOl in listing 1) for use in two-byte instructions; the Mostek and other assemblers do not allow this. Another point: it is impossible to specify an external symbol as having an absolute address. This is due to the fact that the internal sx/mbols (symbols that have an address equated with them, such as SUBl and LOOP in listing 1) do not contain a flag to indicate whether the Hexadecimal Address Hexadecimal Code Instruction Mnemonic Operand Commentary OOOOR OOOOR .ENTRY .EXTRN SUB2 XTR1 this is external symbol 002 1R 20 FFFF t JSR XTR1 first reference (end of 003AR 1 20 00 22 t JSR XTR1 backwards pointer to C 004ER 1 20 00 3B JSR XTR1 backwards pointer to C 006FR .END SUB2 Figure 1: Keeping track of external symbol use with a linked list. When the source file of an assembly -language module (consisting of the columns marked with an asterisk) is assembled into an object module of machine-language bytes, an external symbol record is created which points to the last place that the symbol is used (ie: the last memory location that must be filled with the address of the symbol, once that address is known — after linking). Within the data records that contain the object code for the routine, each reference of the external symbol points to the address of the previous reference, with a value of hexadecimal FFFF terminating the chain; this is shown by the atrows in the second column. 198 September 1980 © BYTE Publications Inc FOR TftS-80* MODEL I USERS ONLY 16 Times Normal Speed *TRS-80 is a trademark of Tandy Corp. High speed load TRS-80 Level II cassettes Input 15K byte Level II program in 15 seconds Search BASIC or SYSTEM programs by name Unlike other high speed tape input de- vices, FASTLOAD uses standard format cassettes. Therefore, there is no need to re-record on other media. At 8000 baud, FASTLOAD is faster than disk for short programs. FASTLOAD reads tapes at the fast-forward speed of the CTR-41 cassette recorder. The recorder can also be used for CSAVE at the normal speed. FASTLOAD connects to the 40 pin I/O or to the Expansion box. The control program does not use computer memory because it is in a built-in PROM. Other valuable features are keyboard debounce program, automatic key repeat routine and key- beep via cassette speaker. Price is $188.00 for FASTLOAD and $95.00 for the modi- fied CTR-41 recorder. Personal Micro Computers Inc. 475 Ellis Street, Mountain View, CA 94043 (415) 968-1604 Circle 119 on inquiry card. BYTE September 1980 199 Listing 2: Use of a separate page-zero assembly module. Use of a module like this on computers that have a set of special page-zero ad- dresses allows page-zero addresses (such as XNOW) and system parameters (such as XMAX) to be defined in a central location. Hexadecimal Address Hexadecimal Code Label Instruction Mnenomic Operand Commentary OOOOR 0000 OOOF .NLIST .ASECT * = 15 common variables turn off the listing enter absolute mode 0010 0011 0012 XNOW YNOW XVEL * = * + l * = * + l * = * + l simulator parameters current horizontal position current vertical position horizontal velocity 00 AO 00 OC XMAX XVMAX EQU EQU 160 12 maximum horizontal location maximum horizontal velocity OOOOR OOOOR .CSECT .LIST re-enter relative mode turn the hsting back on Put your computer in touch with the world. AJ makes it possible for only $185 with the A 242 acoustic data coupler. Experts call it "the best acoustic coupler ever made" Reliability is phenomenal— historically over 35,000 hours mean time between failure! Thousands are in use by companies all over the U.S. And now, the A 242 from A J, refur- bished at the factory, can connect to your terminal or personal computer, putting you in touch with every other compatible terminal or computer. 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BYTE Seplember 1980 201 defined symbol is relative or absolute. This could be changed by adding a flag byte to the internal-symbol record or by splitting the external-symbol record into two types: one for relocatable external symbols, the other for absolute-valued external symbols. Also notice that code cannot be placed in absolute locations, because there is only one kind of data record and it is subject to relocation. In all fairness, I would like to point out that there is a way around most of the problems mentioned above. A separate page-zero assembly module could be created to define both the addresses of all page-zero locations, which would probably have to be done anyway, and the values of all parameters that the system designer might want to change. This idea is demonstrated by the exam- ple given in listing 2. Any good assembler should have some sort of copy command that instructs it to accept in-line source text from a separate file; this could be used to easily include a zero-page module like listing 2 wherever it is needed. A less convenient alternative would be to always prefix the page-zero module to the assembler input stream. This method of information binding (ie: giving a symbol its final value; see references, Elson) has the advantage of forcing the designer to define all assembly variables cen- trally, rather than having them scattered throughout the source code. Unfortunately, a major redefinition of the page-zero module would require reassembly of all associated programs. Also, the additional I/O (in- put/output) for the page-zero module could prove to be time- and resource-consuming on limited systems. I have one more criticism about the proposed standard: it does not allow external variables to be referenced in an operand-arithmetic expression. This can be a strong drawback when referring to many fixed-data structures. Consider the following external declaration, written in FORTRAN: COMMON / STATUS / XNOW, YNOW, XVEL ... / It is possible to decrease both program size and execution time by separating the linking loader into a linker pro- gram (which links together a set of object modules, creating one file of fully defined machine code) and a simpler loader program (which loads the already linked machine code). Relocating Assemblers To an absolute assembler, all variable names are alike; ie: each represents a known value. On the other hand, a relocating assembler must be able to distinguish between three types of entries in its symbol table: • absolute symbols • relative symbols • external symbols When a relocating assembler encounters an arithmetic expression containing more than one symbol, it must determine several things: whether the expression is valid or not; and if it is valid, what its value is and whether an external or a relocation record (if any) need be written. Also, the use of arithmetic operators is limited by the combination of symbols being worked upon. For exam- ple, REL -h EXT is valid if an external record is generated for the resulting sum; REL - REL is always valid; but REL - EXT is always invalid. (REL and EXT refer to a relative and an external symbol, respectively.) The actual rules for combination of symbols are more complicated and must be taken into account when designing a linking assembler. An additional difference is that a relocating assembler must be able to recognize specialized directives. The ones that I have used in this article are: .ASECT enter absolute mode .CSECT enter relative mode .ENTRY define a list of internal symbols .EXTRN define a list of external symbols An external declaration in any compiled language will take this form. Quite obviously, it should be possible to directly address any one of the variables in the common block. However, only the value of STATUS (the begin- ning address of the common block) is available using the proposed Mostek standard; the instruction would be .EXTRN STATUS. This means that a reference to XVEL, for example, could be done only through an address com- putation (ie: its address is equal to that of STATUS plus a certain number of bytes). Needless to say, the result is a waste of machine time, memory, and perhaps micropro- cessor facilities (eg: an index register). This problem directly affects the assembler programmer, since his coding style is interfered with. The most practical alternative would be to allow off- sets in external references. The offset could then be stored in the target location, to be adjusted at link time (the method shown in the program of listing 2). This will necessitate one entry in an external symbol record for each reference to that symbol in a source program. The result is, of course, increased object-module size and in- creased time taken to link or load a given set of modules. In addition to these, there should be a directive to ex- plicitly declare a one-byte external symbol, so that the assembler will know whether or not to generate a short (page-zero) form of an ambiguous instruction. As previously noted, this is most relevant to 6502- and 6800-type processors. As shown in the previous section, a relocating assembler need be only slightly more complex than an absolute assembler, and allows the use of modular soft- ware-generation techniques. Unless the system being developed is extremely small (eg: 512 bytes or less), its advantages easily outweigh its drawbacks. ■ References Elson, M, Concepts of Programming Languages, Science Research Associates, Chicago IL, 1973. Formaniak, P G, and Leitch. D, "A Proposed Microprocessor Software Standard," July 1977 BYTE, page 34. 202 September 1980 © BYTE Publications Inc TO ORDER CALL (212) 687-5000 supe^brain: INTE^TEC DATA SYSTEMS 64K ONLY $2995 32K $2795 More than an intelligent termtnal, the SuperBrain outperforms many other systems costing three to five times as much Endowed with a hefty amount of available software (BASIC. FORTRAN. COBOL), the SuperBrain is ready to take on your toughest assignment. You name it! General Ledger, Accounts Receivable. 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DIP-8lBIDIRECTIONAL| MATRIX PRINTER Centronics interface Serial add S50 Ribbon cartridge| ' American made ' 80 column $495" New ANDERSON JACOBSON Parallel &41 I/O Terminal Ideal for 511 30 Aford processing and . small businesses. o6ri3l ASCII Code S1230 15 CPS Printout '*•«-*'" High Quality Selectric Printing Reliable heavy duty mechanism Completely Refurbished by A.J. Delivered FREE to nearest service center f^ev^ tHaUii XEROX 1730 Letter Quality Printer List $2755 Special $2495 • 40 Cps 90 Day On Site Warranty • Uses all 100 metal & plastic daisy wheels • Automatic bidirectional printing • Fewer moving parts f^mmm XYMEC HQ 1000 with 10, 12, 15 Pitch & Proportional Spacing ' Z-80 controlled ■ return (Direct-Threaded Code) ->A -^B (Mochine Code) B: machine code routine mochine code for next call return next call return JSR/RTS pair JSR instruction RTS instruction Figure 1: Diagram of subroutine-threaded code (STC). In this and figures 2 thru 4, the pointer points to the main program be- ing executed. Both A and B are subprograms called by the main program; A is an intermediate-language subprogram of the same type as the main program, and B is an in-line machine-language program that directly executes the machine language of the host computer. The words next, call, and return refer to operations that must be performed for any threaded-code language. The in- formation to the right of these words tells how each operation is performed in the current type of threaded code. next call return 1. copy current list item to temporary storage 2. point list pointer to next list item 3. jump to machine code at address in temporary storage 1. push current list pointer onto stack 2. load list pointer with address of the intermediate-language subroutine list 3. do "next" 1 . load list pointer with top of stack 2. do "next" Figure 2: Diagram of direct-threaded code (DTC). Here, "tem- porary storage" refers to a memory location that is used to hold the address of the machine-code routine associated with the current unit of code. TERMINALS FROM TRANSNET PURCHASE PLAN 12-24 MONTH FULL OWNERSHIP PLAN 36 MONTH LEASE PLAN DESCRIPTION PURCHASE PRICE PER MONTH 12 MQS. 24 MQS. 36 MOS. 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Here, "in- direct temporary storage" and "code temporary storage" store the indirect and direct pointers to the machine code routine associated with the current unit of code. 210 September 1980 © BYTE Publications Inc Circle 129 on inquiry card. ture into the intermediate language, the parameter trans- fer location is implied and need not be part of the inter- mediate language representation. (A stack architecture is certainly simpler than other architectures, but that does not mean it is better; many complex trade-offs that are beyond the scope of this article are involved.) Threaded Code Threaded code is an intermediate-language implemen- tation technique that organizes the control of program flow into a sequence of subroutine invocations. No other aspects of the language are represented in threaded code. Threaded code is especially applicable to interpretation; the interpretation process consists of transferring control to the routines selected by the threaded-code op codes. The functions available in the intermediate language are provided by the subroutines that are invoked and are not an inherent part of the threaded code itself. [The characteristics of the language FORTH are in- dependent of its current implementation via threaded code. FORTH enthusiasts often blur the distinction, attributing the language's speed and compactness to the language instead of to its threaded-code implementation. I think this is an important point to remember when talk- ing about the advantages of FORTH.... GW] Threaded-code intermediate languages are especially applicable to the implementation of virtual machines em- bodying zero-address architectures. As such, the tech- nique of using threaded code to implement a language can be applied to, for example, Pascal (using the p-code intermediate language), LISP interpreters, or, of course, FORTH. We classify four varieties of threaded code: subroutine, direct, indirect, and token. All varieties of threaded code consist of a data struc- ture that is a sequence of unique subroutine identifiers. Traditionally, threaded code has been kept close to the machine level and has included actual pointers to the subroutines (which themselves may be either interme- diate language or machine code). Also traditionally, a portion of the processor resources — in particular, pro- cessor registers — has been dedicated to the use of the threaded-code interpreter. As we shall see, neither ab- solute pointers nor register resources need be used to im- plement threaded code. Implementing Threaded Structures We will now describe the structures associated with the various types of threaded code. Figures 1 through 4 pre- sent diagrams of subroutine-, direct-, indirect-, and token- threaded code structures, respectively, along with a des- cription of the three operations, next, call, and return, which make up the complete threaded-code interpreter. In the diagrams, the notation "—A" means a pointer to the memory location labeled "A". Subroutine-threaded code: A sequence of subroutine calls with no other embedded instructions implements an intermediate language. Each subroutine call may be con- sidered a single intermediate-language operation, which need not be related to the underlying machine architec- ture. Subroutine-threaded code (STC) is a control mechanism that is widely supported at the machine- hardware level. The peculiar program organization consisting only of The 2nd Generation is shaping up... MEASUREMENT systems &< controls incorporated MicroByte Software rib / 241 5-C Gntewny Plaza ^ L'/ Crabtiee Blvd. Raleiqh, North Carolina 27604 (919) 833-4094 AT LAST! A fully implemented computer based file management system. . . Only a few minutes of instruction and you arc creating and using your own client lists, mailing lists, inventories, bibliographies, vendor lists, and more. 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L'TILS $50.00 Apple PASCAL utilities: extensions to Apple Pascal, together with file control utilities, cross-reference, etc. FAYROIJ $100.00 Apple PASCAL payroll for 150 employees, full deduction options, etc. Write or call today for further details on our products. Source ID#TCK373 AI'Cl.K is u Irudemurk nT Apple Cl l)it-i(a! Rpsearch Owing to a printer error a wrong telephone number was run in August. Our apologies for any inconvenience this caused. Our correct telephone number is 919-833-4094. Circle 130 on inquiry card. September 1980 © BYTE Publications Inc 211 subroutine calls is rarely used by programmers (who have no reason to resist obvious opportunities for op- timization), but it is sometimes used by compilers. It is the most general intermediate language possible, and it retains the advantages of machine independence by not generating in-line machine language. (The difference in the form of subroutine call and return instructions on various computers is usually trivial.) Subroutine-threaded code will incur less execution overhead than most intermediate languages because its interpretation is handled by hardware rather than by a sequence of instructions. Furthermore, subroutine- threaded code can be optimized by using in-line machine code for operations where subroutine overhead is ex- cessive, an advantage unobtainable with other types of threaded code. Of course, the resulting optimized code is no longer machine-independent; the additional transla- tion step converts the intermediate language into object code for a particular machine. Direct-threaded code: Direct-threaded code (DTC) may be considered a sequence of machine-language sub- routine calls with the "call" op code removed. This results in a list of addresses, each of which points to a machine- language subroutine. Since the direct-threaded program includes no op codes, a short machine-language program must be written to read the next address in the list and transfer control to that address. Traditional direct- TABLE: ( indexed by token ) list pointer ; token A token B (IL code) token CO// token L token M token end token A: -^ A token B; -> B token bst : ^ BST token call . -> coll token end \ — ^ return ( Mochine c Dde) B: token bst BST: mactiine code routine mactiine code for next next call return 1 . get current token from list 2. point list pointer to next list item 3. look up address corresponding to token 4. get indirect token at address 5. look up address corresponding to indirect token 6. jump to machine code at that address 1. push current list pointer onto stack 2. load list pointer with start of new list 3. do "next" 1 . load current list pointer from top of stack 2. do "next" Figure 4: Diagram of token-threaded code (TTC). Since tokens can be made shorter than addresses, this makes the threaded code more compact, hut the table lookup makes the resulting code slower. Here, the "indirect token" is the contents of the table entry that matches the current token of code. threaded code implementations do not allow the use of true subroutines at the machine level but instead require that each routine terminate by executing the next opera- tion. In order to call direct-threaded routines (see the instructions for "call" in figure 2), machine-language code (executing the instructions for "call") must be included at the beginning of each direct-threaded routine to put the current value of the list pointer on an address stack, load the list-pointer register with the start address of the list of routine addresses for this just-begun, direct-threaded routine, and execute the next operation. The next operation (coded here as in-line machine code) causes the computer to execute the routine pointed to by the list pointer, regardless of whether the routine pointed to is another intermediate-language routine or a machine-language routine. In order to return to a higher level of nesting, the last list item in an intermediate-language routine points to the code for the return operation. When executed by the next operation, this operation recovers the previous value of the list pointer from the stack, then executes the next operation, which in turn executes the first routine past the routine the computer just returned from. Thus direct-threaded code is implemented in three operations: next, call, and return. Indirect-threaded code: Indirect-threaded code (ITC) consists of a list of addresses, but each address points to another address which then points to the machine-code routine. (See figure 3.) As compared to direct-threaded code, in indirect-threaded code, the interpreter must go through an extra level of indirection. Indirect-threaded intermediate-language subroutines do not contain ma- chine-language code for the call operation, and one ad- vantage of indirect-threaded code is that a compiler using it need only produce pointers. By manipulating only pointers, the compiler generates intermediate-language code that does not include machine-language code itself; thus it is independent of the target machine. However, a disadvantage of indirect-threaded code is that the inter- preter has the overhead of an extra level of indirect ad- dressing. Token-threaded code: The varieties of threaded code previously mentioned contained pointers that were actual addresses of the subroutines in memory. Using memory addresses to select routines wastes storage because the number of subroutines in the system is far smaller than the number of memory locations. A savings in inter- mediate-language program size can be obtained by using short tokens to identify the subroutines to be invoked. Typically, token-threaded code (TTC) can be im- plemented by using the current token to index into a table of subroutine addresses. (See figure 4.) High-Level Descriptions of Threaded-Code Interpreters Listings 1 thru 3 illustrate the logical implementation of direct-, indirect-, and token-threaded code, respectively. The program descriptions are written in a high-level language that is similar in appearance to Pascal. It differs from Pascal in that the variables are not declared as stan- dard Pascal data types. Also, the next, call, and return operations are not written as Pascal procedures; this was done to remain faithful to actual implementations where 212 September 1980 © BYTE Publications Inc THE ULTIMATE REFINEMENT PL/1 FOR YOUR MICRO. IBM's told us about PL/1 for years. Now, we're telling them something. PL/I Subset G. Newly designed expressly for minicomputers by an ANSI committee of PL/I experts. All the best application programming features, refined to match contemporary programming practices. PL/l-80^** for Microcomputers. Based on Subset G, PL/1-80 runs under our CP/M® and MP/M'** operating systems. PL/1-80 Means Performance. In an independent benchmark, PL/1-80 was level languages for 8-bit processors, and came out on top, * PL/1-80 versus the best of several languages: PL/1-80 1.00 FORTRAN 1.21 BASIC COMPILER 1.71 PL/M 1.71 PASCAL COMPILER 1.89 PASCAL INTERPRETER 17.07 BASIC INTERPRETER 34.57 * Execution time ratio, Eratosthenes Sieve Subset G is a brand new language with a new foiiowing. DEC®, Data General, and Prime now support it, and the list is growing. There's no better way lu [jiuiti^uL yuur 2>uuwcti investment. PL/i-80 from Digitai Research. Fast. Economical. Refined. With the programming power of minicomputer PL/I . The package includes compiler, run-time library, linkage editor and relocating macro- assembler, plus three comprehensive manuals. All for only $500. Interested in Refinement? Call or write Digital Research. Experts in refinement. gojDiGJTaHESEflHCh^ P.O. Box 579 801 Lighthouse Avenue Pacific Grove, CA 93950 TWX 9103605001 ^ W I Ji Circle 131 on inquiry card. BYTE September 1980 213 these three code segments are reached by jump instruc- tions rather than by subroutine calls. Several other notational conventions used in these listings may also need explanation. The data type pointer means an actual machine address. If ip is a pointer variable, then -^ ip means the value at the location which is pointed to by the address in variable ip. Therefore, the statement goto -* ip; means jump to a new location using the contents of variable ip as the address at which to proceed with execu- tion. Implementation Concerns The traditional implementations of threaded-code interpreters have had one or more machine registers dedicated to the exclusive use of the interpreter; imple- mentations on microcomputers have tended to use all microprocessor resources. One problem with these imple- mentations is that all machine-language routines (where all real computation is done) must save processor registers before modifying them and must restore them before returning to the interpreter. Additionally, this use of machine resources, simply for the transfer of control, obstructs the use of standard machine-language subroutines that pass parameters through the registers. In the context of microcomputer The world's most popular microcomputer, with 16K of memory and Level 1 1 basic for only $685, complete with full 90 day Radio Shack warranty. We accept check, money order or phone orders with Visa or MasterCharge. (Shipping costs added to charge orders). Disk drives, printers, peripherals, software and games . . . you name it, we've got it (Both Radio Shack & other brands). Write or call for our complete price list. Shown is Level I. Level II includes Alphanumeric Iceypad. CftS ELECTRONICS MART Ltd. AUTHORIZED DEALERSHIP Radio /haeK Listing 1: Description of a direct-threaded code interpreter in a Pascal-like language. See figure 2. const p ointer_length = (length of an address pointer); ca 1 l_c ode_length = (length of "call" code segment); war list_pointer: pointer; -C interpreted program counter > list_item: pointer; -C contains threaded-code item > label next » c a 1 1/ return; next: lis t_ item := '"•list_pointer; list_pointer ;= list_pointer + p o i n ter_l eng t h; goto "^ 1 i s t_i tem; call: push_on_stack(list_pointer); ■C The value of list_item ua s set by the preceding > ■C "next" operation. > list_pointer := list_item + c a 1 l_code_le ng t h; ■C The following code duplicates the "next" operation. > list_item := '"■ 1 i s t_po inter ; list_pointer := list_pointer + p o in ter_leng t h ; goto '^ 1 i st_i tern; return: list_pointer := p op_f r om_s ta c It ( ) ; ■C The following code duplicates the "next" operation. > list_item := '^ 1 i s t_p o inter ; list_pointer := list-pointer + p o i nter_leng t h ; goto '^list^item; Listing 2: Description of an indirect-threaded code interpreter in a Pascal-like language. See figure 3. const poin ter_length = (length of an address pointer) ; "^ar list_pointer: pointer; -C interpreted program counter > list_item: pointer; -C contains threaded-code item > code_p ointer : pointer; -C points to actual machine code > label next » c a 1 1 / return; nex t : call: ■C list_item := '*• 1 i st_po i n ter ; list _p ointer := list _p ointer + pointer_length; code _p ointer := ^•list_item; -C here is the extra > < level of indirection > goto '^code_poin ter; push_on_stac k ( 1 ist_p ointer ) ; The value of list_item uas set by the preceding "next operation, list _p ointer := lis t_ item + pointer_length; The following code duplicates the "next" operation. list_item := '' 1 i st_po i n ter ; 1 ist_poin ter code _p ointer list_pointer + p oi nt er_le ng t h; '■"1 i st_i tem; 32E.MainStreet«MilanMichigan48160«(313)439-1400 I goto '^code_p ointer; return: list_pointer := p op_f r om_sta c k ( ) ; < The following code duplicates the "next" operation. list_item := ''"1 i st_p o inter ; list_pointer := list_pointer + p o in teT_len g t h; code_p ointer := "^list^item; goto '^code_p ointer; Listing 3: Description of a token-threaded code interpreter in a Pascal-like language. See figure 4. const token_length = (length of token) ; call_code_length = (length of "call" code segment); toknumber = (number of tokens possible); < is 256 for an > ■C 8-bit token > var 1 i st_p ointer : pointer; < interpreted program counter > code_pointer: pointer; -C pointer to mathine code > table: array C 1 .. toknumber D of pointer; -Csubroutine table > token item: short token; label nex t( cal 1/ return; next: token_item := '^li st_poi nter; list_pointer := list_pointer + t oken_leng t h; code_pointer := tab leCt o ken_i temD; token_item :«= '^code_p ointer; code_pointer := tab leC t oken_i tem]; goto '^code_p ointer; call: pu5h_on_stac k(list_p ointer); ■C The value of the code_pointer was set by the preceding > ■C "next" operation. > list_pointer ;= c ode_j) ointer + c a 1 l_code_leng t hi •{ The following code duplicates the "next" operation. )■ token_item := ^ 1 ist_pointer; list_pointer ;= list_pointer + to ken_length; code_pointer := tab leCt oken_i temD ; goto '^code_pointer; return: list_pointer := p op_f r om_stac k ( ) ; •C The following code duplicates the "next" operation. > token_item := ^ li st_poin ter; list_pointer := list_pointer + t oken_length; code_pointer := tab leC token_itemD; goto '■ code_pointerj 214 September 1980 © BYTE Publications Inc Circle 132 on inquiry card. 32 K Board Pictured Above Why Not the Best? From The Dynamic RAM Company. 2MHz 4MH2 16K— $249 $259 32K-$375 $395 48K— $500 $530 64K— $625 $665 We have now been shipping our 2MHz dynamic RAM boards for over two years. Hundreds of 4MHz boards have been going out every month since early 1979. Our reliability is proven in the thousands of systems which contain our board. Many quality- minded systems houses across the country and overseas are using our boards for their equipment. Our prices still beat all. Despite rising 16K memory chip prices (at least from reputable suppliers), Central Data continues to give you the best buy In memory today. Nobody offers a board with a capacity of 64K, assembled, tested, and guaranteed for a full year at the price we do. Circle 133 on inquiry card. Deselect around PROMs. Our boards have the important deselect feature which lets you overlap any fixed memory In your system with no Interference. Our features make the board easily used and expanded. You address our boards on 1 6K boundaries with mini-jumps (small shorting plugs that slide over wire- wrap pins) near the top of the board for easy access. If you want to expand your board after you have purchased it, all that you need to do is add memory. We can supply you with expansion packages ($150-2MHz, $1 60-4MHZ) which include eight RAMs that you can depend on as well as two mini-jumps for addressing. And of course, our board never generates wait states. Low power consumption keeps your computer running cool and reliable. The total power consumption of our 1 6K board is typically less than 4 watts (+8V @ 300ma, 4- 1 6V @ 1 50ma and -16V @ 20ma). Boards with additional memory typically increase power consumption only 1 watt per 16K! Standard S-100 Interface. Our board is designed to Interface with any standard S-100 CPU. All of the timing of the board is independent of the processor chip, and the board is set up for different processors by changing two plugs on the board. Call or write us today. That will guarantee a fast response with more information on the board. Or make an order — you'll probably have the board In two weeks! If you're interested, also ask for a catalog on our Z8000 16-bit processor board designed for the MULTIBUS. All of these products are available to your local dealer, also. Central Data Corporation, 713 Edgebrook Drive, PO Box 2530, Station A, Champaign, IL 61820. (217) 359-8010 Central Data BYTE September 1980 215 Listing 4: A simple direct-threaded code interpreter for the MC6809 microprocessor. PULS Y JMP C.Y++3 GET NEW THREAD PTR DO "NEXT" Listing 5: A simple indirect-threaded code interpreter for the MC6809 microprocessor. In this and listings 6 thru 8, each block of information in lowercase is a "stack picture" — ie: a diagram of what is on the stack at that particular place in the code. Machl Routine IL Routine CALL; PSHS Y LEAY ♦+?, PCR JMP C,Y++] JMP C. Y++a FDD RETURN STACK OLD THREAD POINTER ADDR OF FOLLOWING IL CODE ADDR OF "RETURN" systems (which may want to use read-only memory modules), this limitation requires that special "header" and "trailer" code be written to move data values used by the intermediate language to and from the registers used by previously written machine-language code. It is also possible to eliminate the use of processor resources in an intermediate language by storing the interpreter's "registers" in memory; this leaves the pro- cessor free for use by machine-language code at the ex- pense of additional overhead during interpretation. [This overhead consists of having to move these registers be- tween memory, and the hardware registers of the host processor when you want to manipulate the contents of the interpreter registers....GV^] The use of absolute loca- tions in memory would itself be a problem, because these locations can then conflict with locations used by other software packages. By saving the intermediate-language registers on the stack, the language may be made inde- MICRO MISCELLANY APPLE II PARALLEL INTERFACE SOLID STATE SWITCH $79.95 Interfaces printers, synthesizers keyboards, and JBE A-D D-A Converter & Switches. This Interface has 4 I/O ports with handshaking logic, 2-6522 VIA's and a 74LS74 for timing. Inputs and outputs are TTL compatible. 79-295K Complete Kit $69.95 79-295A Assembled $79.95 AtoD DtoA CONVERTER $69.95 Analog to Digital, Digital to Analog Converter, AtoD conversion time 20us. ptoA conversion 5us. Uses include speech and music synthesizing and slow scan TV. Single power supply (5V), 8 Bits wide, latched I/O, strobe lines. 79-287K 79-287A Complete Kit Assembled $49.95 $69.95 $44.95 $12.50 Your computer can control power (120VAC) to your printer, lights, and other 120VAC appliances up to 720 watts (6AMPS at 120VAC). Input 3 to 15 VDC, 2-13 MA TTL compatible, isola- tion 1500V. 79-282 1 Channel Kit $ 9.95 Assm. $12.50 4 Channel Kit $34.95 Assm. $44.95 BARE BOARDS SINGLE BOARD COMPUTERS 8088 5-CHIP SYSTEM 8085 3-CH IP SYSTEM $29.95 $24.95 MEMORY BOARD 8208 64K DYNAMIC ALL PRODUCTS AVAILABLE FROM; JOHN BELL ENGINEERING P.O. Box 338 Dept. 4 Redwood City, CA 94064 (415)367-1137 Add 670 sales tax in California and $1.00 shipping and handling for orders less than $20. Add 470 for VISA or M.C. JOHN BELL ENGINEERING s ->thread thread ptr ptr 1 2 NEXT: LEAS -2, S PSHS X MAKE SPACE SAVE X s ->x space thread thread ptr ptr 1 2 LDX C.V++: STX 2, S GET ADDRESS OF ROUTINE SAVE AS UPCOMING PC s ->x routine adc thread ptr thread ptr r 1 2 PULS X, PC RECOVER X AND GDI s ->thread thread ptr ptr 1 2 CALL: PSHS Y LDY . ~Y LEAY 2, Y BRA NEXT SAVE CURRENT THREAD PTR GET PREVIOUS INDIRECT PTR NEW THREAD PTR RETURN: PULS Y BRA NEXT RECOVER OLD THREAD PTR Listing 6: A more complex direct -threaded code interpreter for the MC6809 microprocessor. Execution of the intermediate- language subroutine starts at the label ENTRY. ->nex t thread ptr 1 thread ptr 2 RETURN: LEAS 2, S PULS V DISCARD "NEXT" GET SAVED THREAD PTR Nl: NEXT: N2: BSR N2 PUSH ADDR OF NEXT s ->thread ptr 2 BRA Nl SET UP RETURN TO NEXT JMP i:,Y++] GO TO ROUTINE s -> next thread ptr 2 I-Code Routine (start at ENTRY) ENTRY: PSHS X SAVE X s - > X thread ptr space next thread ptr 1 thread ptr 2 LDX 6.S GET ADDR OF "NEXT" STX 4, S MOVE IT STY 6,S SAVE OLD THREAD PTR s - >x thread ptr next y (old thread ptr) thread ptr 1 thread ptr 2 PULS X, Y RECOVER X, NEW THREAD PTR JMP C. Y-K+J DO SIMPLE "NEXT" LEAS -2, S MAKE SPACE BSR #-14 PUSH NEW THREAD PTR. GOTO PSHS X ""return START OF THE IL CODE FDB ADDR OF "RETURN" 216 Seplember 1980 © BYTE Publications Inc Circle 134 on inquiry card. PRIAM Hard Disks Now Available from SIRIUS SYSTEMS! PRIAM'S high-performance, low-cost Winchester disc drives speed up ttiroughput and expand data storage from 20 meaabytes to 154 megabytes. And a single controller can be used to operate 14-inch-disc drives with capacities of 33, 66, or 154 megabytes or floppy-disc-size dnVes holding 20and 34 megabytes. So it's easy to move up in capacity, or reduce package size, without changing important system elements or pertomiance. I Fast. Unear Voice Coil Positioning I 10 ms tmck-to-track positioning I Fully servoed head positioning I Dedicated seivo tidcks I DC Power required only! I Sinipie, parallellnterface I Optional SMD Interface I 50 ms Aveiage Positioning time I 90 ms Maximum Positioning Time I 6.4 ms Aveiage LBtency Model/Disc Size DISKOS 3350 DISKOS 6650 DISKOS 15450 DISKOS 2050 DISKOS 3450 DISKOS 570 DISKOS 1070 THE PRIAM LINEUP Capacity 33fVlbytes 66 fVlbytes 154 fVlbytes 20 fVlbytes 34 Mbytes 5.3 Mbytes 10.6 Mbytes Size 7" X 17" X 20" 7" X 17" X 20" 7" X 17" X 20" 4.62" X 8.55" X 14.25" 4.62" X 8.55" X 14.25 " floppy-size Weight 33 lbs. 33 lbs. 33 lbs. 20 lbs. 20 lbs. (low) (low Price $2995 $3749 $4695 $2995 $3745 (low) (low) floppy-size All PRIAM DISKOS Drives have a Transfer Rate of 1 .03 Mbytes/Sec. Optional SMD interface available fa $150. SIRIUS SYTEMS offer cases and enclosures for all PRIAM Hard Disk Drives. All 14" Winchester Drives will mount in our 14" Standard Case. The 8" Winchesters have two alternatives: a single drive case and a dual drive case. All SIRIUS SYSTEMS Winchester drive cases include Power Supply, internal cabling, switches, fan, extra AC outlet (not switched, but fused) and possess ver-y adequate ventilation. Drive addressing is done on the rear of the Case and not on the drive iteself to provide ease of use during operation. All WINCHESTER DRIVE Cases are Warranted for a full year and come in our standard blue-black color scheme. Consult us for current availability and pricing. RemexRFD 0000/4001 8" Floppy Disc Drives Double sided . . . Double density II $549 95 RFD 4001, $569.95 Offers quality and features found in drives costing much more! ■ Single or Double Density ■ Double-Sided Drive ■ Door Lock INCLUDED ■ Write-Protect INCLUDED ■ 180 Day Warranty ■ Compatible with Shugart 850/851 ■ Low Power Operation ensures LONGER LIFE! ! ■ Model RFD 4001 offers Data and Sector Separator RFD 4000/4001 Technical Manual 6.95 Connector Set #3 (AC, DC, Card Edge) . . 1 0.95 RFD 4000C/B Cabinet (for use with Connector Set #4 (AC and DC) 2.95 Power Modules) 29.95 Remex 1000B . . . If you've been looking for a less expensive floppy disc drive, but not wanting to sacrfflce quality — this is It! $419 95 You get both in the Remex 1000B! For only $419.95 look at what you get: ■ 8" Floppy Drive ■ Single or Double Density ■ Hard orSoft Sectoring ■ MediaProtection Features Single Density Data Separator ■ 1 80 Day Factorv Warranty Door Lock Option $19.95 Write Protect Option . . . .$19.95 RFD 1000B Technical Manual .$5.95 Interface Adapter Connector Set #1 RFD 1000B CASE (for use (REMEX-to-Shugart) . , .$14.95 (AC, DC, & Card Edge). . .$10.95 (with Power Modules) $29.95 SIRIUS 8 "DISK POWER MODULES The Single and Dual Drive Power Modules are designed to provide DC and (switched) AC power for one (the Single Drive Power Mod- ule) or two (the Dual Drive Power Module— the DDPM will power three RFD 4000s or 4001s) 8" Floppy Disk Drives. Many features are included lor safe and reliable operation and the Power Modules come with our stan- dard 180 day WARRANTY (the Open Frame Power Supply warranty is for 2 years). All Power Modules will work with either the RFD 4000C/B or RFD 1000B case (color schemes match also). Dual Drive Power Module (DDPM) $139.95 Single Drive Power Module (SDPM) 119.95 SIRIUS 80+ Perfect Add-Ons for Your Computer System! The SIRIUS SYSTEMS 80+ Series of Floppy Disk add-ons are designed to provide un- matched versatility and performance for your computer. Consisting of four different add-ons, there is a 80+ Series Floppy Disk to meet your need. AII80+ Series Floppy Disk are compatible with the TRS-80* and come ready to plug in! COMMON CHARACTERISTICS M 5 ms tiack-to-track access time ■ Auto-eject m IdOdayWARRANH m Exceptional speed stability— /V2% ■ Sinqle density (FM) or double density (MFMI M^FM) m Ultra high reliability ■ 2 year Power Supply Wananty ■ fvfixany orall80+ Series on the same cable! ■ Includes user accessible plugboard for drive reconfiguring SPECIFIC CHARACTERISTICS The SIRIUS 80+1 is a single sided, 40 track, highly reliable Floppy Disk add-on. Offering 5 more tracks than the Radio Shack model, it cost $140 less'. Formatted data storage is 102K/20K bytes single/double density. SIRIUS 80+1 $359.95 The SIRIUS 80+2 is a dual sided, 70 track (35 per side), highly versatile Floppy Disk unit. It appears to the TRS-80' as TWO 35 track drives, yet COST LESS THAN HALF THE PRICE! Even greater savings result, since data is recorded on both sides of the media instead of only a single side. Using the plug board, it may be recon- figured for other computer systems! (The 80+2 operates as Drive and any of the other three addresses (with the sandard Radio Shack Cable) or as any of four drives (with the SS Standad Cable).) Formatted data storage is 80.6K/ 161 ,2K bytes single/double density. SIRIUS 80+2 $449.95 The SIRIUS 80+3 is a single sided, 80 track, "Quad" density Floppy Disk unit. Offering 2V'3 times the storage of a Standard Radio Shack drive, the 80+3 greatly reduces the need for diskettes correspondingly. Additionally, because of the increased storage and faster track-to-track access time, the 80+3 allows tre- mendously increased throughput for disk based programs!!! The 80+3 INCLUDES SIRlUS's TRAKS- PATCH on Diskette. Formatted data storage is 204K/40K8 bytes single/double density. SIRIUS 80+3 $489.95 The SIRIUS 80+4 Floppy Disk add-on is a double sided, 160 track (80 per side), 574" monster! The ultimate in state-of-the-art 574" Floppy Disk technology, to 80+4 is seen by the TRS-80' as two single sided disk drives, each with 80 tracks. Thus, in terms of capacity one 80+4 is equivalent to 4% standard Radio Shack drives — a savings of over 73% (not to mention diskettes!!!). (With a double density converter, the available memory is huge!) The 80+4 is similar to the 80+2 in that it arrives configured as Drive and any of the other three addresses (with the standara Radio Shack Cable) or as any of four drives (with the SS Standard Cable). The 80+4 INCLUDES TRAKS-PATCH on Diskette. (The plug board is also included.) Formatted data storage is 408K single density or 816K bytes double density. SIRIUS 80+4 $624.95 All 80+ Series Floppy Disk add-ons operate a 5 milliseconds track-to-track access time (eight times faster than the SA 400) but are Expansion Interface Limited to 12 milli-seconds for the TRS-80 V 'TRS-80© Tandy Corp. SYSTEMS 7528 Oak Ridge Highway Knoxville, Tennessee 37921 TO ORDER CALL (615) 693-6583 Phone Orders Accepted 9AM-7PM (ESDT) We accept MC, VISA, AE, COD (requires Certified Checl<, Cashier's Check or Cash) and Checks (personal checks require 14 days to clear). SHIPPING AND HANDLING: $7.00 per Floppy Disk Drive or 80+ Module ■ 5% for other items (any excess will be refunded) ■ Foreign Orders add 1 0% for Shipping & Handling. Paynnent in U.S. currency ■ Tennessee residents add 6% Sales Tax ■ VOLUME DISCOUNTS AVAILABLE MPI 51/52 . . . A Great Reliable Mini-Drive! ■ Fast! 5ms trEckto track access ■ Exclusive Pulley-Band Design ■ Unique Door/Ejector Mechanism ■ Reliable V/2% Speed Stability ■ Single/Double Density Operation ■ industry I AN SI Standard Interface MPI 51 (Single Head, 40 tracks. 120K/240K ^^^^ ^^ bytes Single/Double Density") $259.95 MPI 52 (Dual Head, 70 tracks, (35/side), 218.8K/437.5K Single/Double Den- ^^^^ ^^ sity-) $349.95 MPI 91/92... NEW STATE-OF-THE-ART DISK DRIVE! MPI 91 (Single Head, 80 tracks, 240K/480K ^^^^ ^^ Single/Double Density) $389.95 MPI 92 (Single Head, 160 t acks (80/side), 480K/960K Single/Double Den- ^ ^^ sity ') $499.95 ** Unformatted data stoiage Introducing the Versatile, low-cost OiviEGA series Controller As new technological advances bring down the cost of fast, reliable mass data storage, the need for an inexpensive, versatile controller have be- come greater and greater. To meet this need, SIRIUS SYSTEMS' OMEGA Series Controller was designed. The SIRIUS OMEGA Series Controller Module utilizes an on-board microprocessor to mediate data transfer to a wide variety of peripherals from an equally wide variety of host computer systems. Up to four Winchester Hard Disks (8" or 14"), four5y4" Floppy Disks Drives and/or up to eight 8" Floppy Disk Drives may be in use at one time. Host systems interlacing is accomplished via a parallel or a serial inter- face. With the additon of a Personality module, the OMEGA Series Controller Module is directly compatible with many popular com- puter systems (among them the TRS-80*, Apple, Heath, and others). Provision ismadefor the addition of a streaming tape drive, also. SPECIFIC HARDWARE FEATURES INCLUDE: ■ Control of up to twelve Floppy Disk Drives (eiqht & ' and lor four 5 Va ' ') • 8" and lor 5W Disk Drive Utilization • Single (FM) or Double (MFM) density data storage • Hard or Soft sectored diskette usage • Utilization of "Quad" density, (96 tpi) 8" or SVa" Disk Drives ■ Control of up to four WmCHESJER type PRIAM DISKOS Disk Dnves • 8" or 14" may intermix on the same cable • Accommodates 5" and lor 14" drives of 5.3Mbytes to 154Mbytes • Ultra-tast data transfers ■ Extremely flexible host-controller inteiiacing SPECIFIC SOFTWARE FEATURES INCLUDE: ■ Dynamic format modifications via command words ■ Extremely flexible format acceptance for un- usual data storage formats ■ Easily interfaces to standard operating sys- tems (TRS-DOS *, CP/M •••, etc) ■ Operates in either get/put sector mode or data string mode ■ Perf omiance parameters may be changed by EPROM replacement or Dynaminic depro- gramming Dedicated systems cards are also available on a limited basis for the STD-BUS and the S 100. These cards featureshared memory also (again, software selectable) in addition to the regular OMEGA Series Controller Module features. Con- sult SIRIUS SYTEMS for current price and availability for the entire line of OMEGA Series Memory Units and Controllers. Dealer inquir- ies are invited. Circle 135 on inquiry card. BYTE September 1980 217 Software can be written to function properly on widely varying computers that use the same microprocessor. pendent of particular programmable memory locations. Another way to eliminate the use of processor re- sources, as well as maximize throughput, is to use subroutine-threaded code (STC). Subroutine-threaded code makes use of only the program counter and the sub- routine return stack, resources already dedicated to the control of program flow. Thus, the processor resources traditionally available to the programmer remain free for use by machine-language code. Distribution of Software It is possible to conceive of a mass market for software; such a market would allow high-quality programs to be distributed at low cost. We will assume that such code will be distributed in the form of read-only memory modules, so that a purchaser actually receives a physical product for his money. Furthermore, the memory needed to store the program is included in the purchase price, a characteristic not obtained with distribution on magnetic media. Software piracy will be possible for advanced hobbyists, but these represent only a small portion of the consumer market. To maximize sales, it is necessary that everyone who has a computer and who wants to use the program be able to do so. Given machine-language distribution, the market is already limited to those users with a particular processor; it should not also be limited to those users with a particular computer system. Software can be written such that it functions properly on systems that use different locations for programmable memory, read-only memory, and input/output (I/O) de- vices, as well as systems that use completely different I/O devices. The system-independent read-only memory must be written in code that is position independent, and it must also include features for linking to other similar modules. These criteria can be satisfied with machine- language code (on certain processors) or with a correctly designed intermediate language. Widest distribution re- quires such properly written code. Machine-Language Examples of Threaded-Code Interpreters Here we present assembly-language code for the Motorola MC6809 microprocessor which implements complete interpreters for direct-threaded code, indirect- threaded code, and token-threaded code. Most of these listings are punctuated by "stack pictures" (typed in lowercase) that represent the current state of the stack at various points in the listing; visualization of the stack is often crucial to understanding the interpretive process. An illustration of subroutine-threaded code (using subroutine jump and return instructions) would be trivial, and thus is not included. However, it should be noted that a position-independent form of subroutine- threaded code is available on computers with long rela- N6}!1 Produced and widely used in England and U.S.A. COMPLETE BUSINESS PACKAGE INCLUDES EVERYTHING FROM INVENTORY TO SALES SUMMARY PROMPTS USER, VALIDATES EACH ENTRY, MENU DRIVEN Approximately 60-100 entries/Inputs require only 2-4 hours weekly and your entire business is under control. PROGRAMS ARE INTEGRATED- SELECT FUNCTION BY NUMBER- 13 = PRINT CUSTOMER STATEMENTS 14= PRINT SUPPLIER STATEMENTS 15 = PRINT AGENT STATEMENTS 16 = PRINT TAX STATEMENTS 17 = PRINT WEEK/MONTH SALES 18= PRINT WEEK/MONTH PURCHASES 19= PRINT YEAR AUDIT 20= PRINT PROFIT/LOSS ACCOUNT 21 = UPDATE END MONTH FILES MAINTENANCE 22= PRINT CASH FLOW FORECAST 23= ENTER/UPDATE PAYROLL (NOT YET AVAILABLE) 24= RETURN TO BASIC WHICH ONE? (ENTER 1-24) 01 SUB. MENU EXAMPLE: 01 = EXAMINE: 02 = INSERT: 03 = AMEND: 04 = DELETE 05 = PRINT (1,2,3): 06 = NUMERIC COMBINATIONS: 07 = SORT VERY FLEXIBLE. ADD YOUR OWN FUNCTIONS. EASY TO INTEGRATE. All programs In BASIC for CP/M. PET. 6800 G. W. COMPUTERS LTD, the producers of this beautiful package in U.K. 01 = ENTER NAMES/ADDRESS, ETC 02 = ENTER/PRINT INVOICES 03= ENTER PURCHASES 04= ENTER A/C RECEIVABLES 05= ENTER A/C PAYABLES 06= ENTER/UPDATE INVENTORY 07 = ENTER/UPDATE ORDERS 08= ENTER/UPDATE BANKS 09 = EXAMINE/MONITOR SALES LEDGER 10 = EXAMINE/MONITOR PURCHASE LEDGER 11 = EXAMINE/MONITOR (INCOMPLETE RECORDS) 12 = EXAMINE PRODUCT SALES WE EXPORT TO ALL COUNTRIES: BARCLAYCARD ACCEPTED CBM APPROVED CP/M Ver. 9.00 is one 16 K core program using random access releasing both drives for data storage, and 250 word vocabulary Is translatable in any foreign language. PRICES: Programs 1-23 EXC (19,20,22,23) £475 CALLERS BY APPOINTMENT ONLY 89 Bedford Court Mansions Bedford Avenue London WC1. U.K. CONTACT TONY WINTER 01-636-8210 BARCLAYCARD ACCEPTED CBM APPROVED CP/M Ver. 9.00 is one 16 K core program using random access releasing both drives for data storage, and 250 word vocabulary is translatable in any foreign language. £575 Stock Integrated Option + £100 Bank Integrated Option + £100 218 Seplember 1980 © BYTE Publicalions Inc Circle 136 on Inquiry card. Is Expandability the Reason Over 200,000 Smart Buyers Chose TR$-80? Or is it Price? Or . . . Maybe these customers came to Radio Shack for their computer because they knew they could get nationwide service? Or buy a Model I micro starter system for $499? Or because Radio Shack started the boom in reliable little computers? But come they did. And coming they still are! "Who Wants One That Can't Grow?" This question was asked by Radio Shack's president before TRS-80™ went to market. So we made memory expandable from 4K to 48K RAM (in 16K leaps). We made ROM expandable and BASIC upgradable. We provided for the addition of disk drives, printers, acoustic couplers and other peripherals. We have a great new upper/lower case conversion, and a SCRIPSIT™ package that makes TRS-80 Model I a great bargain in Word Processing. ''Be Better Than Competition!" "Not merely cheaper," he said, "not just more popular," he said. "Better!" That includes software, hardware, service, monitor size, keyboards, salesmen, store fronts, peripherals and RAMs. If you own a TRS-80, let us show you how to better your system and its benefits. If you're still on the sidelines . . . shouldn't you play with us? After all. Radio Shack and TRS-80 have FAST DELIVERY FROM STOCK or a very short wait. Most (if not all) the competitors are much slower players! Expansion Interface The hub of an expanded TRS-80 system. Holds up to 32K more mem- ory! Has interfaces for printer, 4 disk drives, second cassette. Also takes RS-232C interface card. ^299 Save MOO Mini-Disk Drives Reg $399 '''' each Quality engineered disk drives let you store and retrieve data and programs fast. Sale ends 9/30/80. Order Today! tive branch instructions (eg: the LBSR, long branch-to- subroutine, and RTS, return-from-subroutine, instruc- tions on the MC6809). Listing 4 illustrates a very simple implementation of a direct-threaded code interpreter. This particular imple- mentation is very fast, but it has the following undesirable properties: • it requires a special machine-language return instruc- tion (ie: JMP[,Y+ + ] ); • it reserves the Y register for use by the interpreter; • it requires that the interpreter location (the address of RETURN) be known to the compiler, making the resulting intermediate-language code definitely position-dependent. In operation, the Y register points to the next address in a direct-threaded code list; that address, of course, points directly to machine code. Executing the operation JMP [,Y-[--[-] (indirect, autoincrement by 2) causes the machine to start execution at the address contained in the list element; simultaneously, the Y register is updated to point at the next item in the list of addresses. The single instruction JMP [,Y-[--[-] ends each machine-language subroutine. By reserving a processor register for use as the current thread pointer, a speed ad- vantage is obtained; transfer of control using JMP [,Y-f- + ] requires nine machine cycles (on the MC6809), while a JSR-RTS pair requires thirteen. The situation becomes more complex when control is transferred to a subroutine composed of intermediate- language statements. Machine-language instructions are included at the beginning of the intermediate-language subroutine to perform the call operation. The Y register may be thought of as the topmost location of the stack of intermediate-language return addresses; its contents are pushed onto the stack, and Y is loaded with the address of the start of the intermediate-language subroutine list. The last item in an intermediate language list is the address of the return routine. This recovers an old inter- mediate-language pointer from the stack and continues interpretation where it left off when it did a subroutine call. In listing 5, we show a very simple indirect-threaded code interpreter. As in the previous example, the inter- pretation process is fast, but again it has the following limitations: • it must use a position-dependent, machine-language return instruction (eg: JMP NEXT); • it uses the Y register to hold the list pointer; • it still requires that the compiler generate position- dependent pointers to the CALL and RETURN routines. Listing 6 is an example of a moderately complex direct- threaded code interpreter. It is somewhat slower than the simple interpreter in listing 4, but it uses a standard RTS instruction to return from machine-language routines. Thus, the machine-language routines need not contain pointers to the next operation. Still, this advantage is bought at the expense of additional machine-language code in each intermediate-language subroutine. The intermediate-language subroutines themselves do have Listing 7: An improved direct-threaded code interpreter for the MC6809 microprocessor. This interpreter does not use any of the microprocessor registers. s ->ptr to new thread addr of "next" old thread ptr CALL: PSHS D SAVE D LDD 2, S GET NEW PTR STD 4, S THREAD PTR s ->d space new thread ptr old thread ptr PULS D RECOVER D LEAS 2, S DELETE SPACE NEXT: LEAS -4, S s ->space space thread ptr MORE SPACE RETURN: PSHS X,D s ->d X space space thread ptr SAVE X, D LDX 8, S GET THREAD PTR LDD , X++ GET NEXT MACHL ADDR STX 8,S STACK THREAD PTR STD 4,S STACK ROUTINE ADDR LEAX NEXT,PCR GET ADDR OF "NEXT" STX h, S SAVE AS MACHL RETURN s ->d X machl rout: ine addr of "next- thread ptr PULS D, X,PC GO TO MACHL ROUTINE s ->addr of "next" thread ptr I-CODE: JSR CALL ... Listing 8: Token-indirect token-threaded interpreter for the MC6809 microprocessor. Because of the use of two levels of lookup, this interpreter is completely position independent. s ~> table addr old ind irect thread ptr NEXT: LEAS -4, S PSHS U, X, D s -> d X u space space tab le addr ind irect thread ptr MAKE FREE STACK SPACE SAVE REGISTERS Listing 8 continued on page 222 220 September 1980 © BYTE Publications Inc Pascal/MT® + The Choice of Professionals, Worldwide Pascal/MT + is an enhanced version of our successful Pascal/MT package popular with both hardware and software engineers. Generating even more optimized ROMable 8080/ZBO object code [directly from the Pascal source], Pascal/MT + now includes those features demanded by today's professional. We've added modular compilation and linking [incorporating the industry standard linker format used by FORTRAN and PL7I] and user selectable ZBO native code or our enhanced 8080/ZBO object code. Also included is an improved SYMBOLIC DEBUG, more I/O facilities and even an option to produce pseudo assembly output intermixed with the Pascal source. MODULAR COMPILATION Pascal/MT + generates the same industry standard relocatable code used in FORTRAN and PL/I. Pascal code may be linked with our linker or any compatible linker. Both Pascal and assembly language modules may be separately compiled and then combined to produce a final program. With modular compilation available, the run time overhead becomes as small as 256 bytes, and is typically 1200 bytes. OPTIMIZED NATIVE OBJECT CODE Pascal/MT + now produces even more optimized object code than before. Now included is a compile- time selectable option to generate ZBO code where it is more efficient. The 8080/8085 code is better, too. IMPROVED DEBUGGING FACILITIES The Pascal/MT + debugger is improved. We've added facilities to use the debugger with larger programs and even in a ROM-based environment. The compiler can also output a disassembled listing of your programs with the Pascal source code interspersed between the object code. This helps you gain visibility in non-CP/M® applications. ENHANCED I/O CAPABILITIES To our already powerful console, printer and re-directable I/O facilities we have added Pascal standard TEXT file I/O as well as improved line editing for console I/O. PLUS . . . • Transcendental functions • Improved String Handling • Benchmark tests rate our code up to 10 times faster than P-code Pascal and faster than other native code high level languages too! • Re-assembly of the run-time package no longer required for ROM based applications! AND OUR STANDARD FEATURES: High speed compilation [up to 2000 lines per minute] Non-CP/M® environments supported CP/M® file support Program chaining Built-in mini-assembler Compile-time constants Business [1 8-digit] arithmetic Scientific [6.5 digit] arithmetic AMD951 1 Hardware support Source code for run-time package included [re-assembly now requires Macro-80 assembler] I/O port, Interrupt facilities Bit and Byte manipulation Many useful built-in procedures [loaded from run-time library] SYSTEM REQUIREMENTS To execute the Pascal/MT + system you must have a CP/M® system with at least 32K of memory. For larger applications we recommend 48K or more. Source programs are pre- pared using ED [or equivalent], we recommend WORD-MASTER. [Coming soon: versions for Intel ISIS- II and Heath HDDS. Ask us.] ORDERING STILL ONLY S250 will buy you one of the best software power tools available. Pascal/MT + has been chosen by companies such as GE. FMG and Chromatics [as well as over 700 other companies] as the Pascal for them, why not join them! The Pascal/MT + package: • BCD compiler • Roating point compiler • Linker • Interactive Symbolic Debugger • Run time package in Source and Object form. • Pascal library utility routines • 95 + page user's guide • Sample programs The user's guide is available for $30.00. refundable with a system purchase. MT micros YSTEMS has a very reasonable graduated, one time royalty arrangement for free standing software generated by Pascal/MT. Ask us. To order Pascal/MT + write or call: ii \ MT MicroSYSTEMS 1 562 Kings Cross Drive Cardiff. CA 92007 [714] 753-4856 We ship on 8" single density and 5-1/4" North Star single density. Other formats available. Ask us. CP/M is a trademark of Digital Research Pascal/MT is a trademark of MT microSYSTEMS Circle 137 on inquiry card. BYTE September 1980 221 BUSINESS - PROFESSIONAL - GAME SOFTWARE FOR APPLE AND TRS-80 n HOME FINANCE PAK I: Complete package $49.95 Apple, TRS-80 r~| BUDGET: The heart of a comprehensive home finance system. Allows user to define up to 20 budget items. Actual expense input can be by keyboard or by automatic reading of CHECKBOOK II files. Costs are automatically sorted and compared with budget. BUDGET produces both monthly actual/budget/variance report and a yearto-date by month summary of actual costs. Color graphics display of expenses. . .S24.95 Q CHECKBOOK II: This extensive program keeps complete records of each check/deposit. Unique check entry system allows user to set up common check purpose and recipient categories. Upon entry you select from this predefined menue to minimi2e keying in a lot of data. Unique names can also be stored for com- pleteness. Rapid access to check files. Check register display scrolls for ease of review. 40 column print- out. Up to lOOcheckspermonth storage. Files accessible by BUDGET program S19.95 CH SAVINGS: Allows user to keep track of deposits/withdrawals for up to 10 savings accounts. Cpmplete recordsshown via screen or 40 column printer S14.95 Q CREDIT CARD: Keep control of your cards withthisprogram. Qrganizcs.stores and displays purchases, payments and service charges. Screen or 40 column printer display. Up to 10 separate cards S14.95 DTHE UNIVERSAL COMPUTING MACHINE: $39.95 Apple, TRS-80 A user programmable computing system structured around a 20 rowx 20 column table. User defines row and column names and equations forming a unique computing machine. Table elements can be multiplied, divided, subtracted or added to any other element. User can define repeated functions common to a row or column greatly simplifying table setup. Hundreds of unique computing machines can be defined, used, stored and recalled, with or without old data, for later use. Excellent for sales forecasts, engineering design analysis, budgets, inventory lists, income statements, production planning, project cost estimates-in short for any planning, analysis or reporting problem that can be solved with a table. Unique curser commands allow you to move to any element, change its value and immediately see the effect on other table values. Entire table can be printed by machine pages (user-defined 3-5 columns) on a 40 column printer. Transform your com- puter into a UNIVERSAL COMPUTING MACHINE. I ICOLOR CALENDAR: hires color graphics display of your personal calendar. Automatic multiple entry of repetitive events. Review at a glance important dates, appointments, anniversaries, birth days, action dates, etc. over a 5 year period. Graphic calendar marks dates. Printer and screen display a summary report by month of your full text describing each day's action item or event. Ideal for anyone with a busy calendar . . (Apple Only) S19.95 □ business SOFTWARE SERIES: Entire package $199.95 Apple, TRS 80 Q MICROACCOUNTANT: The ideal system for the small cash business. Based on classic T-accounts and double-entry bookkeeping, this efficient program records and produces reports on account balances, general ledger journals, revenue and expenses. Screen or 40 column printer reports. Handles up to 500 journal entries per period, up to 100 accounts. Instructions include a short primer in Financial Accounting. S49.95 G UNIVERSAL BUSINESS MACHINE: This program is designed to SIMPLIFY and SAVE TIME for the serious businessman who must periodically Analyze, Plan and Estimate. The programwascreated using our Universal Computing Machine and it is programmed to provide the following planning and forecasting tools, CASH FLOW ANALYSIS PROFORMA BALANCE SHEET SOURCE ANO USE OF FUNDS PROFORMA PROFITS LOSS SALES FORECASTER JOB COST ESTIMATOR Price, includingdocumentation and a copy of thebase program. Universal Caiii|iiiting Machine . . . .S89.95 QlNVOICE: Throw away your pens. Use the ELECTRONIC INVOICE facsimile displayed on your CRT. The program prompts and you fill in the data. Includes 3 address fields (yours. Bill to and Ship to), Invoice No., Account No., Order No., Salesman, Terms, Ship Code, FOB Pt. and Date, Up to 10 items per sheet with these descriptions: Item No., No. of units. Unit Price, Product Code, Product Description, Total Dollar amount per item and invoice total dollar amount. Generates, at your option, hard copy invoices, shipping memos, mailing labels, audit copies and disc updates to master A/R files. (48K) $49.95 G BUSINESS CHECK REGISTER: Expanded version of the Checkbook II program. Handles up to 500 checks per month wit:i complete record keeping, (48K) S29.95 LJ BUSINESS BUDGET: As described above and companion program to Business Check Reuister. Handles 500 transactions per month, up to 20 cost categories. Accesses BCR files for actual costs. (48K) . . . S29 95 □ ELECTRICAL ENGINEERING SERIES: Both programs SI 59.95 Apple G LOGIC SIMULATOR: SAVE TIME ANO MONEY. Simulate your digital logic circuits before you build them. CMOS, TTL, or whatever, if it's digital logic, this program can handle it. The program is an inter active, menu driven, full-fledged logic simulator capable of simulating the bit-time by tiit-time response of a logic network to user-specified input patterns. It will handle up to 1000 gates, including NANOS, NORS, IN- verters, FLIP FLOPS, SHIFT REGISTERS, COUNTERS and user-defined MACROS. Up to 40 user-defined, random, or binary input patterns. Simulation results displayed on CRT or printer. Accepts network des- criptions from keyboard or from LOGIC DESIGNER for simulation. Specify 1000 gate version (48K re- quired) or 500 gate version (32K required) S89.95 GLOGIC DESIGNER: Interactive HI-RES Graphics program for designing digital Ingic systems. A menu driven series of keyboard commands allows you to drawdirectly on the screen up to 15 differentgate types, including 10 gate shape patterns supplied with the program and 5 reserved for user specification. Standard patterns supplied are NAND, NOR, INVERTER, EX-OR, TFLOP, JK FLOP, DFLOP, RS-FLOP, 4 Bit COUNTER and N-BIT SHIFT REGISTER. User interconnects gates just as you would normally draw using line graphics commands. Network descriptions for LOGIC SIMULATOR generated simultaneously with the CRT diagram being drawn. Drawing is done in pages of up to 20 gates. Up to 50 pages (10 per disc) can be drawn, saved and recalled. Specify 1000 gate (48K) or 500 gate (32K) system S89.95 □ mathematics SERIES: Complete Package $49.95 Apple only G NUMERICAL ANALYSIS: HI-RES 2-Dimensional plot of any function. Automatic scaling. At your option, the program will plot the function, plot the INTEGRAL, plot the DERIVATIVE, determine the ROOTS, find the MAXIMA and MINIMA and listthe INTEGRAL VALUE. For 16K S19.95 G MATRIX: A general purpose, menu driven program for determininii the INVERSE and DETERMINANT of any matrix, as well as the SOLUTION to any set of SIMULTANEOUS LINEAR EQUATIONS. Disk I/O for data save. Specify 55 eqn. set (48K) or 35 eqn. (32K) S19.95 G 3D SURFACE PLOTTER: Explore the ELEGANCE and BEAUTY of MATHEMATICS by creating HIRES PLOTS of 3dimensional surfaces from any 3variable equation. Disc save and recall routines for plots. Menu driven to vary sur-face parameters. Demos include BLACK HOLE gravitational curvature equations. . SI 9.95 □ action adventure games SERIES: Entire series $29.95 Apple only GREO BARON: Can you outfly the RED BARON? This fast action game simulates a machine gun DOG- FIGHT between your WORLD WAR I BIPLANE and the baron's. Yau can LOOP, DIVE, BANK or CLIMB in any one of 8 directions - and so can the BARON, in HIRES graphics S14.95 G BATTLE OF MIDWAY: You are in command of the U.S.S. HORNETS' DIVE BOMBER squadron. Your targets are the Aircraft carriers, Akagi, Soryu and Kaga, You must fly yout way through ZEROS and AA FIRE to make your DIVE-BOMB run. In HI-RES graphics S14.95 DSUB ATTACK: It's April, 1943. The enemy convoy is headed for the CORAL SEA. Your sub, the MORAY, has just sighted the CARRIERS and BATTLESHIPS. Easy pickings. But watch out for the DE- STROYERS they're fast and deadly. In HI-RES graphics S14.95 G FREE CATALOG-AII programs are supplied In disc and run on Apiile II w/Oisc & Applesoft ROM Card & TRS'BO Level II and require 32K RAM unless otherwise noted. Detailed instructions included. Orders shipped within 3 days. Card users include card number. Add SI. 50 postage and handling with each order. ^^^^^M California residents add 67;% sales tax. Make checks payable to: •^ SPECTRUM SOFTWARE DEALER INQUIRIES P.O. BOX 20B4 - 142 CARLOW, SUNNYVALE, CA 94087 INVITED FOR PHONE ORDERS - 408-738-43B7 Listing 8 continued: LDU 10, S LDX 14, S LDB 1 X + STX 14, S CLRA ASLB ROLA LDX D, U ADDD 4, S TFR D, X LDB , X+ STX 12, S CLRA ASLB ROLA LDD D, U ADD 4, S TFR D, X STX 6, S LEAX NEXT, PCR STX 8,S PULS D, X,U, PC GET TABLE ADDR GET THREAD PTR GET INDIRECT TOKEN SAVE THREAD PTR TWO BYTES PER TOKEN TABLE-RELATIVE INDIRECT PTR NOW ABSOLUTE GET TOKEN SAVE INDIRECT PTR TABLE-RELATIVE MACHL ADDR NOW ABSOLUTE SAVE AS UPCOMING PC ADDR OF NEXT SAVE FOR MACHL RTS RECOVER REGS + GO! s -> addr of "next" table addr ind irect thread ptr CALL: PSHS D SAVE D -> d addr of "next" tab le addr ind irect thread ptr LDD 4; S STD 2, S PULS D BRA NEXT RETURN: PSHS D GET TABLE ADDR MOVE IT RECOVER D SAVE D -> d addr of "next" tab le addr old indirect thread ptr 1 thread ptr 2 LDD 4, S STD 6, S LDD 0, S LEAS 6, S BRA NEXT GET TABLE ADDR MOVE IT RECOVER D DISCARD JUNK pointers to the return operation, of course (making the code position-dependent), and the interpreter reserves the Y register for its own use. Listing 7 illustrates a direct-threaded code interpreter that does not reserve any processor registers; this inter- preter also allows the return from machine-language routines by means of a standard RTS instruction. The ab- solute locations of the interpreter call and return routines must be included in each direct-threaded code sub- routine; this usually precludes the distribution of such subroutines in read-only memory. 222 Septeinber 1980 © BYTE Publications Inc Circle 138 on inquiry card. SMC-100 Hard disk and hardtapecontrol Up to 2400 Megabytes of hard disk control for the S-IOObus. Konan's SMC- 1 00 interfaces S-1 00 bus micro computers with all hard disk drives having the Industry Standard SMD Interface. It is available with software drivers for most popular operating systems. Each SMC-1 00 controls up to 4 drives ranging from 8 to 600 megabytes per drive, including most "Winchester" drives -- such as Kennedy, Control Data, Fujitsu, Calcomp, Microdata, Memorex, Ampex, and others. SMC-1 00 is a sophisticated, reliable system for transferring data at fast 6 to 1 megahertz rates with onboard sector buffering, sector interleaving, and DMA. SMC- 1 OO's low cost-per-megabyte advanced technology keeps your micro computer system micro-priced. Excellent quantily discounts are available. Konan's HARDTAPE " subsystem . , . very low cost tape and/or hard disk Winchester backup and more. Konan's new DAT- 100 Single Board Controller interfaces with a 1 Tli megabyte (unformatted) cartridge tape drive as well as the Marksman Winchester disk drive by Century Data. "me DAT- 100 "hardtape" system is the only logical way to provide backup for "Winchester" type hard disk systems. (Yields complete hard disk backup with data verification in 20-25 minutes.) Konan's HARDTAPF^ subsystem is available off the shelf as a complete tape and disk mass storage system or an inexpensive tape and/or disk subsystem. Konan controllers and subsystems support most popular software packages including FAMOS^^, CP/M® version 2.X, and MP/M. Konan, first (and still the leader) in high- reliability tape and disk mass storage devices, offers OEM's, dealers and other users continuing diagnostic support and strong warranties. Usual delivery is off the shelf to 30 days with complete subsystems on hand for immediate delivery. Call Konan's TOLL FREE ORDER LINE today: 800-528-4563 Or write to Bob L Gramley Konan Corporation, 1448 N. 27th Avenue Phoenix, AZ 85009. TWX/TELEX 910951 1552 CP/M® is a registered trade name of Digital Research, FAMOS^M is a trade name of MVT Micro Computer Systems. HARDTAPE™ is a trade name of Konan Corporation. Circle 139 o n inquiry card. BYTE September 1980 223 Type of Threaded Code MC6809 Machine Cycles Used Ratio of Cycles Used Relative Size of Resulting Intermediate- Language Code Can this Code Be Marketed to All Users of a Given Microprocessor? Subroutine-threaded code 91 1.0 3 no Relative subroutine-threaded code 98 1.1 3 yes Simple direct-threaded code (listing 4) 93 1.1 2 no Simple indirect-threaded code (as in listing 5) 371 4.1 2 no Moderately complex direct- threaded code (as in listing 6) 228 2.5 2 no Improved direct-threaded code (as in listing 7) 552 6.1 2 no Token-threaded code (as in listing 8) 1083 11.9 1 yes Table 1: Comparison of threaded-code techniques, code and the token-indirect token-threaded code tially) all users of a given microprocessor. Notice that only two forms of threaded code, the relative subroutine-threaded ire sufficiently system-independent to be used for mass distribution to (poten- A possible alternative would be to modify the direct- threaded code interpreter in listing 7 to use strictly self- relative pointers. Then by including code for call and return in each read-only memory device, a form of distributable direct-threaded code might be obtained. However, because the read-only memory still contains machine-dependent code, the use of direct-threaded code in a read-only memory environment offers little advan- tage. The improved direct-threaded code interpreter allows the use of most previously coded machine-language modules and allows these routines to pass parameters through the processor registers. Routines cannot pass parameters on the hardware stack (which is used to main- tain the state of the interpreter), but could easily use the user stack of the MC6809 microprocessor for parameter transfer. A similarly improved interpreter could be built for indirect-threaded code, but the position-independence problem is inherent in this intermediate language as well. Each indirect-threaded subroutine must include a pointer to the call routine, thus making the resulting intermediate-language code unsuitable for distribution in read-only memory. However, it is possible to build a token-thread inter- preter that has a completely position-independent intermediate-language representation. Listing 8 shows one implementation that achieves these goals. Notice the increased complexity and overhead when compared to our original direct-threaded code interpreter. This token-thread interpreter produces intermediate- language code that is more compact than that produced by previously mentioned interpreters. The advantage of a compact representation need not affect execution speed severely; remember that the overall efficiency of any in- terpretation scheme (including the hardware interpreta- tion of op codes) depends more upon the work actually accomplished than the time spent in the interpretation process itself. This particular implementation is essentially a token- indirect token-thread interpreter. Two levels of token lookup are involved so that neither machine-language nor absolute addresses need be included as part of the intermediate-language subroutine. Of course, perhaps $ GOLD DISK $ CP/M® Compatible Z-80 Disassembler . RECREATES Z-SO ASSEMBLY LANGUAGE SOURCE FILES FROM ABSOLUTE CODE (.COM FILES) FOR ALTERATION. $ - FEATURES MNEMONIC LABELS FOR EASY PROGRAM TRACING. - INCLUDES COMPLETE DOCUMENTATION AND FREE UTILITY FOR SPECIFYING AND DECODING ASCII SECTIONS OF CODE. " OPERATES UNDER MINIMUM CP/M' CONFIGURATION (16K RAM). ' DOCUMENTATION ONLY: $12 (MAY BE APPLIED TO DISK ORDER). BOWER-STEWART & ASSOCIATES P.O. BOX 1389 ggoo POSTPAID ONE DAY SERVICE FOR CREDIT CARD CUSTOMERS: ORDER DISK BY PHONE FREE! (WE WILL PAY YOU BACK FOR THE PHONE CALL) CALIF. RESIDENTS ADD 6 7. SALES TAX. HAWTHORNE, CA. 90250 (213) 676-5055 •WORTH ITS WEIGHT IN GOLD* SPECIFY DRIVE AND SYSTEM AVAILABLE ON 5^4" OR 8" IBM SS/SD DISK •CP/M IS A TRADEMARK OF DIGITAL RESEARCH 224 September 1980 © BYTE Publications Inc Circle 140 on inquiry card. f jm rr /on Software and Hardw^ 3/W t/ TRS-80 and AppI A new enhanced NEWDOS for the TRS-80. The most powerful Disk Operating System for the TRS-80 designed for the sophisticated user and professional program- mer who demands the ultimate. NEWDOS/80 Is the planned upgrade from NEWDOS 2.1. Some of the features are: • New BASIC commands for files with variable record lengths up to 4095. • Mix or match drives. Use 35, 40 or 77 track 5" disk drives or 8" disk drives, or combo. • Security boot-up for BASIC or machine code application programs. • New editing commands. • Enhanced RENUMber that allows relocation. • Command chaining. • Print Spooler. • DFG function; striking of D, F and G keys allows user to enter a mini-DOS without disturbing program. • Compatible with NEWDOS 8. TRSDOS. • Machine language Superzap/80, 2.1 utilities and enhanced copy by file commands. • Enter debug any time by pressing 123 keys. Also allows disk I/O. • Diskette "Purge" command. • Specifiable system options (limited sysgen type commands). • Increased directory capacity. $149 Disk Drive Sale! $70 worth of FREE merchandise with purchase of Shugart SA400 with powersupplyand chassis, the disk that Radio Shack sells for $499. SAVE $200 $369 TF-Pertec FD200, 40 track, use both sides $389 TF-5 MPI B51. 40 track. $389 TF-70 Micropolis, 77 track with 195K storage $639 TDH-1 Dual Sided drive. 35 track $499 NEWDOS^, 40 track ..$110 35 track $ 99 Business Programs (Interactive A/R, A/P, 8. GL) $349 Radex Data Base Program $ 99 Mailing List $59 Drives for any microcomputer Does not include power supply &. cabinet. Pertec FD200 .... $ 282 FD250 $ 399 Shugart SA400 . . $ 279 SA800/801 $ 479 MPI B51 $ 279 B52 $ 349 Centronics 779 ..$1,069 Base 2 $ 599 / || Centronics 737 Text processing capabili- ties, lower case descenders, underlining, subscripts and superscripts, 80 cps $899 Spln%JS^ $2,549 A new disk operating system for tiie Apple. Fully Professional DOS for the Apple II. The result of two years of extensive development, APEX provides a complete program development and file management system, both powerful and useable. A comprehensive command set allows the user to perform almost any Imaginable disk operation. Here are some of APLX's features: • Command structure similar to CPM and main frame systems. Contains 20 command words, with ability to treat external programs as transient commands to the operat- ing system. • Scrolling editor compatible with VIdex 80 char. card. • Easy program interface. Simple communications between the DOS and user program. • Capable of handling 5 Inch, 8 Inch and hard disks. • Safety features to protect against accidental data loss. Features Include backup files, directory, read-after-write and limit checks. • 4 times fastec than CPM. • Auto default structure eliminates tedious typing by auto- matically setting up command strings, file names, etc. • Functional on both single and multi-drive systems. Includes ultllitles for file copy. • Device handler structure for interfacing peripherals. The APEX package includes all of the tools for a complete assembly language development system, high speed two pas^ resident assembler and a powerful macro editor. The complete APEX package with operating system, as- sembler, editor and manuals also includes utilities to maintain files on single or multiple drive systems. $99 Related Software XPLQ FOCAL'" $79 $59 Disk Drive Expansion System • 2 Shugart SA400 drives with "^''^" power/chassis $ 738 • I Two-Drive Cable $ 25 • 1 Expansion Interface 32K $ 499 • 1 35-track DOS+ % 99 TOTAL LIST PRICE $1,361 . SPECIAL PRICE ONLY #| |QQ MOD I 8" Disk System • One SASOOR Floppy • 2 Drive Chassis and Power Supply ^ ^ ^^^r • DOS and Cable >1 ,095 MOD II 8" Disk System • 3 Drive Chassis ^ | 3OO • 2 Drive Expansion System # ■ j J . 3rd Drive . . . Add $479 I More Savings NEW SALE PIUCE TRS-80 Graphics, OkldaUMkrollneSO... *^ - ^^rlTe $699 Save on Apple II 16K Introductory Offer- FREE memoiy upgrade kit Mini-Floppy for Apple . ^ ^ ^ to 48K with purchase of (2nd Drive) . . . Only >4 I 9 Apple lil6K II iQc Apple 8" Disk System • One SA800R Floppy • 2 Drive Chassis &. Power Supply ^ ^ m Mg\ • Controller, Cable and DOS > 1 ^44 V 16K Memory Upgrade Kits $ 79 '/MlCROCQA^PUrER [■^k TECHNOLOGY (303) .....a , INCORPORATE) 4401S.TamaracPkwy. • Denver. CO 80237 • (303) 758-7275 ^ 3304 W. Mac Arthur • Santa Ana. CA 92704 • (714)979-9923 All prices cash discounted/Freight: FOB factory. Ask for our free catalog. Sr Circle 142 for Apparat Circle 141 for MTI BYTE September 1980 225 other, more advantageous forms of token-threaded code interpreters are possible. However, we have shown that there is no longer a question whether position- independent threaded code is possible; now the question is: "at what cost?" The Cost of Implementation The claims made for threaded-code techniques in an intermediate-language implementation include reduced program storage and high speed of execution. Unfor- tunately, these claims are justified only in certain limited contexts. The original implementations of threaded code, which occurred on the Digital Equipment Corpora- tion PDP-11, made use of the instruction JMP @(Rn)+ ; this instruction jumps through a memory pointer while retaining the location of next in a register. This is equivalent to the MC6809 instruction JMP [,r+ + ] . The instruction JMP @(Rn)+ does not save a return address on a memory stack and thus is faster than a JSR instruction. In the environment of a single intermediate- language program that calls only machine-language sub- routines, stacking and unstacking of the return address need not occur. Of course, when intermediate-language programs call intermediate-language subroutines, such stacking must occur in a process that will take longer than a normal JSR. Thus, for maximum speed, the threaded-code intermediate-language program should not call intermediate-language subroutines. On the other hand, the instruction JMP @(Rn)+ does eliminate the in-line 16-bit JSR op code for a 50% code reduction (on the PDP-11). But the 50% code reduction U^jfii^. ilf Computers ti Comblins Moeosina^ PRESENTS: \ PROBABILITY HANDICAPPING DEVICE I A 16K BASIC PROGRAM FOR: HORSE RACE HANDICAPPING! This amazing program was written by a professional software consultant to TRW Space Systems and is being introduced by the publishers of Computers and Gambling Products Magazina "PHD-1 " is a large complex basic program requiring a full 1 6K. It is care^lly human factored for easy use. PHD-1 is a comprehensive horse racing system for spotting overlays in thoroughbred sprint races (less than 1 mile). You simply sit down with your computer and the Racing Form the night before the race and answer 5 or 6 questions about each horse's past performance. Your computer then accurately predicts the win probability and odds-line for each horse allowing you to spot overlaid horses while at the track. The users manual contains a complete explanation of overlay betting. Statistics for thousands of horses were used to develop this handicapping system. The appendix of the manual contains a detailed tab run of a 100 consecutive race system workout showing an amazing 45% positive return |45c for each Si. 00 wagered). A graph is also included showing PHD-I's close fit to the ideal predicted probability vs. actual win percentage curve. This program features: D Win probability and odds for each horse D Verification display of each horse's parameters prior to entry for easy error correction D Bubble-^ort routine for final display D Facility for line printer output D Cassette ARCHIVE routine to store PHD-I's output for later analysis D Complete users manual. The user's manual may be ordered separately for your perusal for 87.95 and will be credited if you purchase PHD-1 . Order now to get on our list and receive back Issues FREEl PHD-1 User's Manual and 16K Cassette for: Apple II Applesoft Challenger (Specify Type), TRS-BOt Level II $29.95 Ca. res. add 6% Make checks payable to: JOE COMPUTER 22713 Ventura Blvd., Suite F, Woodland Hills, CA 91364 * BE A WINNER; Get on the Computers and Gambling Products Magazine mailing listfor $3.00 and receive available back issues. t TRS'80 /s a registered trademark of Tandy Corporation. achieved on the PDP-11 (which uses a 16-bit JSR op code) is only a 33% code reduction on most microcomputers, which have 8-bit JSR op codes. (The LBSR instruction can be used in the case of the MC6809.) And if the motivation for threaded code is reduction of the intermediate-language code size, token-threaded code implementations can improve the storage efficiency by another 50%. The two traditional forms of threaded code (direct and indirect) are optimized for the environment of a par- ticular computer architecture that is represented by the PDP-11 (and also reflected in the MC6809). Consequent- ly, many microcomputer threaded-code implementations have provided neither maximum code efficiency nor maximum speed and have devoured virtually all of the machine-level microprocessor resources. Comparisons of the four types of threaded code demonstrate that it is unlikely that the speed and code-efficiency maxima will ever coincide. The main factor affecting code compaction is the use of subroutines instead of in-line code; but the use of subroutines inherently increases interpretation overhead. Since all methods of threaded-code implementation allow the use of subroutines, effects due to the use of subroutines can be disregarded and the efficiency of the implementation methods can be compared directly. Table 1 shows this comparison with values from the machine-language routines developed earlier (based on six next operations for each call and return operation). Conclusions Languages that have been historically associated with threaded code will probably continue to use these tech- niques when implemented on microcomputers. New implementations should take advantage of the inter- pretive nature of threaded code to provide extensive debugging facilities. However, there is no excuse for the threaded-code implementor to prohibit the use of pre- viously coded machine-language modules by eliminating parameter passage through microprocessor registers. Either the interpreter can be designed to keep these registers free, or special routines must be written by the implementor to save and restore these registers when using library routines stored in read-only memory. Similarly, the motivation for distributing software in an open market (to many different users with many dif- ferent systems) leads directly to the requirement for posi- tion independence. While the MC6809 directly supports position-independent code at the machine-language level, it is also possible to devise threaded-code intermediate languages that are position independent. But any inter- mediate language or interpreter that requires particular absolute storage locations is so obnoxious as to be un- worthy of discussion in polite programming society. Absolute-address storage requirements are simply unac- ceptable in code written for mass distribution. Within these constraints, the various forms of threaded code offer different trade-offs of speed and code effi- ciency. Because these forms are logically equivalent, a single compiler could be used to generate any of them at the user's choice. Thus, without changing the source pro- gram, a threaded-code technique could be selected that would give the desired trade-off between speed and code efficiency for a particular situation. In the end, threaded-code implementation techniques 226 September 1980 © BYTE Publicalions Inc Circle 143 on inquiry card. are neither particularly compact nor are they particularly fast. Continued development of direct-threaded code structures could result in a language representation that would look more like Pascal p-code than threaded code. Threaded code does offer a conceptually simple and general control-transfer technique that displays a clear boundary between interpretation and language. However, threaded code is probably not an optimal representation for any particular language, including FORTH. ■ Bibliography 1) Bartholdi, P, Stepwise Development and Debuging (sic) Using a Small Well Structured Interactive Language for Data Acquisition and Instrument Control. Copy received from the author. (Author's ad- dress: Observatoire De Geneve, CH-1290-Sauverny, Switzerland.) 2) Bell, James R, "Threaded Code," Communications of the ACM, volume 16, number 6, June 1973, pages 370 thru 372. 3) Dewar, Robert K, "Indirect Threaded Code," Communications of the ACM, volume 18, number 6, June 1975, pages 330 thru 331. 4) Dewar, Robert K and A P McCann, "MACRO SPITBOL— A SN0B0L4 Compiler," Softv^are Practice and Experience, volume 7, number 1 , 1977, pages 95 thru 113. 5) fig-FORTH Installation Manual, FORTH Interest Group, San Carlos CA, May 1979. 6) FORTH Dimensions, volume 1, numbers 1 to 4, FORTH Interest Group, San Carlos CA. 7) Gaebler, Robert F, "Make it Natural," Electronics, volume 52, number 14, July 5, 1979, page 6. 8) Grappel, Robert D, "STRUBAL vs FORTH," Dr Dobb's Journal, volume 3, number 8, September 1978, page 28. 9) Brinch Hansen, Per and C Heyden, "Microcomputer Comparison," Softv^are Practice and Experience, volume 9, number 3, 1979, pages 211 thru 217. 10) James, John S, "FORTH Dump Programs," Dr Dobb's Journal, volume 3, number 28, September 1978, pages 26 thru 27. 1 1) James, John, "FORTH for Microcomputers," Dr Dobb's Journal, volume 3, number 25, May 1978, pages 26 thru 27. 12) Main, Richard B, "FORTH vs Assembly," Dr Dobb's Journal, volume 4, number 31, January 1979, pages 45 thru 47. 13) Meinzer, Karl, "IPS, An Unorthodox High Level Language," January 1979 BYTE, volume 4, number 1, pages 146 thru 159. ^A)MicroFORTH Primer. FORTH Inc, Hermosa Beach CA, December 1976. 15) Moore, Charles H, "FORTH: A New Way to Program a Mini- Computer," Astronomical Astrophysics Supplement, volume 15, 1974, pages 497 thru 511. 16) Moore, Charles H , and Elizabeth D Rather, "The Use of FORTH in Process Control," Proceedings of the International Mini-Micro Com- puter Conference, Geneva, March 26, 1977. 17) Oliver, John P, "Astronomy Application for PET FORTH," Dr Dobb's Journal, volume 3, number 30, November and December 1978, page 46. 18) Phillips, J B, M F Burke, and G S Wilson, "Threaded Code for Laboratory Computers," Softv^are — Practice and Experience, volume 8, 1978, pages 257 thru 263. 19) Rather, Elizabeth D, and Charles H Moore, "The FORTH Ap- proach to Operating Systems," ACM '76 Proceedings, October 1976, pages 233 thru 240. 20) Rawson, Edward B, "Let it Be," Electronics, February 14 1980, volume 52, number 4, page 8. 21) Ritter, Terry F, and Joel Boney, "A Microprocessor for the Revolution: The 6809 — Part 1: Design Philosophy," January 1979 BYTE, volume 4, number 1, pages 14 thru 42; "Part 2: Instruction Set Dead Ends, Old Trails and Apologies," February 1979 BYTE, volume 4, number 2, pages 32 thru 42; "Part 3: Final Thoughts," March 1979 BYTE, volume 4, number 3, pages 46 thru 52. 22) Roichel, Ancelme, "SAM76-FORTH-STRUBAL," Dr Dobb's Jour- nal, volume 3, number 30, November and December 1978, pages 44 thru 45. 23) Sachs, John, STOIC (Stack Oriented Interactive Compiler), MIT and Harvard Biomedical Engineering Center, Cambridge MA, 1977. 24) Sirag, David J. "DTC Versus ITC for FORTH on the PDP-11," FORTH Dimensions, volume 1 , number 3, June and July 1978, pages 25 thru 29. The 2nd Generation... It's all that it's Cracked up to be. MEASUREMENT systems &v controls incorporated CP/M®us»s- The ED-80 TEXT EDITOR $50,000 in Development Costs - Yours for Only $99! For all CP/M, Cromemco, TRS-80 Mod II, and North Star Systems. Full Screen Text Editor w/Scrolling. For all CRT and Video Monitors. Features Found only on IBM, CDC, UNIVAC and DEC Systems. Forward or Backward Locate and Change Commands. Field Proven — More than 2 Years. A Terrific Value — $99 00 Write for FREE Color Brochure [! Software Development & Training, Inc. Post Office Box 4511, Dept. B Huntsville, Alabama 35802 VISA or MC Circle 144 on inquiry card. September 1980 © BYTE Publications Inc 227 CCMipCIIO! TRS-80 Level-ll, 4K Level-ll 16K no keypad Level-ll 16K with keypad COMM-80 Interface CHATTER BOX Interface Dlsk-80 Interface Expansion Interface, no RAM Expansion Interface 16K RAM Expansion Interface 32K RAM RS-232-C Board TRS-232 Printer Interface 16K Memory Kit. TRS-Keyboard 16K Memory Kit. TRS-Exp. Int Percom, TFD-100. 40-track Percom, Dual TFD-100 Drives Percom. TFD-200. 77-track Percom Data Separator Percom Extender Card 2-Drive Cable 4-Drive Cable Data Dubber Percom Electric Crayon w/cbl Busy Box, TRS-80 BSR X-10 Starter Kit Busy Box 4-yr Control Program ATARI ATARI 400Comp. System, 8K ATARI 800Comp. System 16K ATARI 410 Program Recorder ATARI 810 Disk Drive ATARI 815 Dual Density Disks ATARI 820 Printer (40 col.) ATARI 822 Thermal Printer ATARI 825 Printer ATARI 830 Acoustic Modem ATARI 850 Interface Module ATARI Light Pen 8K RAM Memory Module 16K RAM Memory Module ATARI Joystick Controllers ATARI Paddle Controllers CARRYING CASES TRS-80 Computer Case TRS-80 Monitor Case APPLE System Case w/1 drive APPLE System Case w/2 drive APPLE _.^^^^^, System Case w/mon. 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CBM Cassette Recorder CBM 2040 Dual Disk Drives CBM 8050 Dual Disk Drives CBM Modem CBM Voice Synthesizer CBM to IEEE Cable IEEE to IEEE Cable PRINTERS Centronics 730 Centronics 737 Centronics 779 Centronics 779 w/lower case & motor control NEC 5510 SpinWriter NEC 5520 SpinWriter NEC 5530 SpinWriter NEC Tractor-Feed Option LRC 7000 -h (64-col.) LRC 7000 -h (40-col.) Okidata Microline-80 Tractor-Feed Option RS-232-C (2K) Option LRC to TRS-80 or APPLE LRC to PET, IEEE LRC to RS232C, male/female 730 or 737 to TRS-80 NEC or 779 to TRS-80 RS-232-C/RS-232-C male/male DUST COVERS TRS-80 (3pc set) APPLE ATARI 800 ATARI 400 PET/CBM 2001 *TRS-80, ATARI, APPLE, and PET/CBM are trademarks oJ Tandy Corp, Warner Apple Computer Co., and Commodore respectively. List Our \ Price Price \ $280.00 $262.50 $200.00 $187.50 $119.00 $85.00 $114.95 $99.95 $124.95 $99.95 $995.00 $895.00 $1295.00 $1195.00 $1795.00 $1619.00 $95.00 $84.95 $1295.00 $1195.00 $1695.00 $1495.00 $395.00 $349.00 $395.00 $349.00 $40.00 $37.50 $40.00 $37.50 $795.00 $699.00 $995.00 $875.00 $1559.00 $1095.00 $1779.00 $1295.00 $3195.00 $2595.00 $3395.00 $2895.00 $3195.00 $2495.00 $225.00 $195.00 $405.00 $349.00 $389.00 $339.00 $800.00 $709.00 $140.00 $129.00 $299.00 $279.00 $20.00 $59.00 $65.00 $29.00 $35.00 $24.95 $7.95 $7.95 $7.95 $7.95 $11.95 jy Corp, Warner Communications. 6 SOUTH ST . MILfORD. NH 03055 To order: Call Toll-free 1-800-258-1790 (m nh cau (603)673-5i44) The Software txchsnge & HardSide (Div of Rohiiaitiv & Son',, [nterpn . In< I. S<)/fS;(/(' Pdhln.i 228 BYTE September 1980 Circle 145 on inquiry card. Where can you dial one TOLL FREE number and be able to select the finest software from the world's foremost suppliers? 800-15S The Software Exchange Our stockrooms are overflowing with the finest software available in today's marketplace. We carry software from all these companies: •Racet • Synergistic Software •Acorn Software • Adventure International • Strategic Simulations • Hayden • Personal Software •Lance Micklus • Muse •Web Associates • Softape • Microsoft • Small Systems Software •Quality Software •Apparat • Sensational Software • Image Products We could not possibly list all of the software on this page, however, if .you send us $1.00, you'll receive our catalog plus a $2.00 credit toward your next purchase! Suppose you and your family could spend a little time each month with someone who truly understands microcomputers. And this person talked to you about your computer in plain oT everyday English. Suppose you could find out how these people are successfully dealing with the ever-increasing technology of the' microcomputer. Suppose too, that each article was geared to the person with a beginning or intermediate interest in personal computing. NOW you can get all this, and more, at a price you can afford. It's SoftSide — the magazine that provides its readers with tried and true istings, along with structured "walk-thrus" of some of the most stimulating software pieces, month after enjoyable month. 1/ Subscribe today! Until November 1, 1980, the price is only $15.00. After November 1, the price will be $18.00, so why not save $3.00 and start your family on the road to microcomputing? ® A SoftSide Publication m maC ^^M^Ww^^^rC CXCmWSiBigC 6 SOUTH st., milford. nh 03055 To order: Call Toil-Free 1-800-258-1790 an nh can (603) 673-5144) The Software Exchange & HardSide (Div of Robil<}illv & Sons, tniorpriw,. tnc }. SoftSnio Puhln I Circle 146 on inquiry card. BYTE September 1980 229 Ef3ucstion Fopum New Cultures from New Technologies Seymour Papert, Project LOGO, Massachusetts Institute of Technology, Artificial Intelligence Laboratory, 545 Technology Sq, Cambridge MA 02139 When I was asked to write this Education Forum for BYTE, I was in the process of correcting the proofs of my book, Mindstorms: Children, Computers and Powerful Ideas. (See reference 1.) There I struggled to present in two hundred pages a vision of a few ways in which com- puters might affect how children learn; it is challenging now to find the right 3000 words to convey something of the same vision. What images, what metaphors best cap- ture for me the essence of the computer as it might enter the lives of children? I start with an image, more general than the computer, that has helped me to think about how the world takes up any new technology. The first movies were made by set- ting the newly invented motion-picture camera in front of a stage where a play was performed just as plays always had been. Only after some time did cinema become more than theatre plus camera. When it did, what emerged was Desk Desk Main/Frame LOW COST & AnRACTIVE STYLING • MAIN/FRAME INTEGRATED INTO FURNITURE QUALITY DESK • ELECTRONICS PACKAGE SLIDE MOUNTED FOR EASY ACCESS • SUPPORTS TWO 8" FLOPPY DRIVES FROM SEVERAL MANUFAC- TURERS (DRIVES NOT INCLUDED) • 10 SLOT MOTHERBOARD INCLUDES CONNECTORS • POWER SUPPLY FOR DRIVES AND CARDS • DESK AND MAIN/FRAME AVAILABLE SEPARATELY • MATCHING PRINTER DESK AVAILABLE WRITE OR CALL FOR OUR BROCHURE WHICH INCLUDES OUR APPLICATION NOTE: 'BUILDING CHEAP COMPUTERS' INTEGRAND 8474 Ave. 296 • Visalia, CA 93277 • (209) 733-9288 VVe accept BankAmericard/Visa and MasterCharge something original and unique, a whole new culture with new modes of thinking and new breeds of people — stars, directors, scriptwriters, cameramen, critics, and au- diences whose sensitivities, expectations, and ways of seeing were quite different from those of the theatre-goers of the past. So too with the computer. The first instinct of educators is to couple the new technology to their old methods of instruction. My vision is of something much grander. So I dream of using this powerful technology not to "improve' known (and, to be honest, with something better. I new the schools we have always hated) but to replace them do not believe that this something will look anything like what is now known as "computer-aided instruction" (CAI). I think it will be more like the growth of a new culture, a "computer culture" in which the presence of computers will have been so integrated into new ways to think about ourselves and about the subject matters we learn that the nature of learning itself will be transformed. In thinking about the nature of such potential transfor- mation, the LOGO group of the Massachusetts Institute of Technology (MIT) Artificial Intelligence Laboratory has been guided by the idea of creating computer-based environments in which mathematics and other areas of "formal" learning can be learned in a natural fashion, much as a child learns to speak; and applying concepts from artificial intelligence to children's learning, to help children become articulate about, and thus gain control over, the learning process. Before developing these ideas, I would like readers to clear their minds of a misleading but common image. People generally think about com- puters in schools as a scarce resource to which students have occasional access. It is time we learned to think in terms of a computer for every child, and we should think about children having access to computers from infancy. If we think in these terms, we begin to recognize that there is a clear discontinuity between the current ideas about using computers in schools and the situation of the future. I really believe that almost everything being done today is only relevant to the future in that it sets a bad ex- ample so that people become accustomed to primitive models. A natural place to begin a search for "something new in education" is to look for examples of highly successful learning. For me the most dramatic image of successful learning is the way children learn to talk. This learning contrasts with school learning in many ways, of which I think two are most important. First, it is highly suc- cessful: all children learn to speak the colloquial dialect in which they grow up. Second, it has none of the technical paraphernalia of schooling — no curriculum, no set lesson times, no quizzes, no grades, no professional teachers. It is part of living. I call it learning-without-teaching or 230 September 1980 © BYTE Publications Inc Circle 147 on inquiry card. AID IT 15I\IT !! ^Mo No this isn't a "Hard Disk". We used to call it that, sometimes. But somebody muddied the water. "Hard Disk", unfortunately, now calls something else to mind. That little bitty guy with no backup capability and no way of switching media? It's a "Hard Disk" to work with, all right, in business applications. Some even say "Impossible Disk". We'd like to avoid confusion between our Cameo database solution and the one that doesn't work so well. The Cameo DC-500 subsystem employs a decade-proven cartridge disk. Our backup capability is built in, and takes four minutes. The ability to switch applications (by exchanging the removable cartridge) means you can use your computer for more kinds of work. A ten megabyte (5 fixed + 5 removable) subsystem costs $5995, for your TRS-80* (Mod. I or II), Apple*, Heath H89"^ or S-100 computer. So call us "The Cartridge Disk Guys", please, and call us soon. We'll show you the really cost-effective solution to microcomputer database storage. AMEO. ELECTRONICS IIMC 1626 CLEMENTINE ANAHEIM , CA 92802 (714)535-1682 * TRS-80 is a registered trademark of the Tandy Corp. *Apple is a registered trademark of Apple Corp. Circle 148 on inquiry card. BYTE September 1980 231 MTQOQK for Tue Jan ! - Not printed since the last change IDennis Johnson/Hi sdOM. Mooth extraction 9^efl ! ■ =18 IKathyNelsoft>check up.. :Ed Jones/check up and.. [Judith Uashingiorv [restoration Carter/check up. S(ched niMber or s(>ace for a neM display, or Q to quit INTRODUCING DATEBOOK" THE NEW OFFICE APPOINTMENT CALENDAR PROGRAM DATEBOOK helps manage time just like a com- mon office appointment book, but with the speed and accuracy of a computer. DATEBOOK^*^ elim- inates the scribbles, erasures, and frustration of searching thiough the book for a specific opening. DATEBOOK''' is ideal for Doctors, Dentists, Law- yers, Salesmen, Repainnen, or in any situation where time management is critical to office efficiency. Its menu display and one-key options make DATE- BOOK one of the easiest programs to leain and use. DATEBOOK'"" features include: • Appointment scheduling, cancelling, modify- ing and rescheduling. • Automatically searches for openings according to time of day, day of week, and week of year. • Displays all scheduled appointments for a specified person. • Lists day's schedule (Screen or hard copy). • Can be customized to accommodate any workday/hours schedule. DATEBOOK'"" is written in PASCAL and is avail- able to run on CP/M as well as UCSD PASCAL systems. (415) 455-4034 T- . « only Sp^WW \\VJiJW /A? Dealer discounts available. naturally ^ bug free 1492 Windsor Way, Livermore, CA 94550 Piagetian learning (after the Swiss philosopher-scientist Jean Piaget who has done more than anyone else to show us how very much children learn in this way). Much of the work done to date in the whole area of computers and education — eg: CAI — has promoted a style of learning that gives the impression of a child being "programmed" by the computer. Our approach has been diametrically opposed to that. By striving to make the computer's processes as transparent as possible and creating activities in which children "teach" (ie: program) computers in a well-structured, procedural language like LOGO, we have aimed toward putting children in con- trol of their own learning. Obviously, I cannot hope to explore these ideas in much depth in a short space. What I shall try to do is to describe a couple of learning en- vironments we have created which I believe challenge the fundamental assumptions our society makes about children and learning. Mathland The belief that only a few people are mathematically minded is a truism in our culture and a cornerstone of our educational system. It is therefore sobering to reflect on the flimsiness of our reasons for believing it. In fact, the only evidence is crass empiricism: look around and you will see that most people are very poor at mathematics. But look around and see how poor most Americans are at speaking French. Does anyone draw the conclusion that most Americans are "not French-minded?", that they are not capable of learning French? Of course not! We all know that these same people would have learned to speak French perfectly well had they grown up in France. If there is any question of lack of aptitude, the aptitude they lack is not for French as such but for learning French in schools. Could the same be true of mathematics? Could there be a place, a "mathland," which is to mathematics as France is to French, where children would learn to speak mathematics as easily and as successfully as they learn to speak their native dialect? I believe that the answer is Yes. In Mindstorms I sug- gest that the world we live in contains pockets of mathland, which explains why all children learn some mathematics spontaneously (eg: one-to-one cor- respondences, conservation of number, reversibility of logical operations) and some children become very good at it. Here I have space only to talk about some ways in which the world could become much more of a mathland for everyone. Computers are the Proteus of machines: they take on many different forms. One of their manifestations is as mathematics-speaking beings. If children grew up sur- rounded by such beings, the learning of mathematics might very well be much like the learning of spoken language. Developing and testing this image has become a central research question for us at MIT: under what conditions will children talk in mathematical languages to mathematics-speaking computers? The results have already convinced us that the idea of mathland is fun- damentally sound and that, indeed, what the mathematics schools fail to teach can be learned suc- cessfully on the model of picking up living languages. But computers do not automatically create that result. For example, instructing computers in FORTRAN to 232 September 1980 © BYTE Publications Inc Circle 149 on inquiry card. What do you need? Program listings . . . inventory listings . . . custom logos and letters . . . mailing labels in a multitude of sizes . . . custom forms and the data to complete them . . . curve plotting or bar graphs . . . digitized images from video or bit pads . . . multi-part forms . . . preprinted forms . . . tickets . . . and the list goes on . . . How do we do it? High speed bi-directional full logic printing; two standard character sets, upper/lower case with descenders; high speed font at 165 cps; letter quality font at 90 cps; expanded characters, solid underlining; programmable character sets; complete dot control graphics; adjustable tractor feed 3"-16"; user adjustable platen; programmable tabs, forms length and line spacing; out of paper signal; self -test; interface options — RS-232C, Centronics parallel, Apple, S-100; and the list goes on . . . The Malibu Model 165 Find out if it's the easy solution to your hard copy needs — contact your local computer dealer or you can write or call us today for complete specifications and print samples — you won't be disappointed. Versatility, Quality and Reliability: We build it in. malibu Electronics Corporation Dealers and OEM'S, call us about our new purchase programs with prices, terms and delivery to meet your needs too. 2301 Townsgate Road, Westlake Village, CA 91361 (805)496-1990 a subsidiary of Oafcarr^Arlcs CorpcxaUon Circle 150 on Inquiry card. BYTE September 1980 233 DYNACOMP Quality software for: PET Apple II Plus TRS-80 (Level II) North Star All software is supplied with complete documentation which includes clear explanations and examples. Each program will run with standard terminals (32 characters or wider) and within 16K program memory space. Except where noted, all software is available on PET cassette, North Star diskette (North Star BASIC), TRS-80 cassette (Level II) and Apple cassette {Applesoft BASIC). These programs are also available on PAPER TAPE (Microsoft BASIC). BRIDGE 2.0 Price: S17.95 postpaid 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 com- puter opponents will either play the offense OR defense. If you bid too high the com- puter will double your contract! BRIDGE 2.0 provides challenging entertainment for advanced players and is an excellent learning tool for the bridge novice. HEARTS 1.5 Price: $14.95 postpaid 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 play- ing strategies. FLIGHT SIMULATOR Price: $17.95 postpaid (as described in SIMULATION, Volume II) 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 flyer can also perform loops, half-rolls and similar acrobatic maneuvers. SIMULATION, Volume II (BYTE Publications): 56.00 VALDEZ Price: S14.95 postpaid A simulation of supertanker navigation in the Prince William Sound and Valdez Narrows. The program uses an extensive 256X256 element radar map and employs physical models of ship response and tidal patterns. Chart your own course through ship and iceberg traffic. Any standard terminal may be used for display. CHESS MASTER Price: S19.95 postpaid (available for North Star and TRS-80 only) This complete and very powerful program provides f ivelevels of play. It includes castl- ing, 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 max- imize execution speed, the program is written in assembly language (by SOFFWARE SPECIALISTS of California), Full graphics are employed in the TRS-80 version, and two widths of alphanumeric display are provided to accommodate North Star users. FOURIER ANALYZER Price: $14.95 postpaid Use this program to examine the frequency spectra of limited duration signals. The program features automatic scaling and plotting of the input data and results. Prac- tical applications include the analysis of complicated patterns in such fields as elec- tronics, communications and business. TEXT EDITOR I (Letter Writer) Price: $14.95 postpaid An easy to use, line-oriented text editor which provides variable line widths and simple paragraph indexing. This text editor is ideally suited for composing letters and is quite capable of handling much larger jobs. MAIL LIST II Price: S19.95 postpaid (available for North Staronly) This many-featured program now includes full alphabetic and zip code sorting as well as file merging. Entries can be retrieved by user-defined code, client name or Zip Code. The printout format allows the use of standard size address labels. Each diskette can store more than 1000 entries (single density; over 2(X)0 with double density systems)! STARTREK 3.2 Price: $9.95 postpaid 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! The situation is hectic when the Enterprise is besieged by three heavy cruisers and a starbase S.O.S. is received! The Klingons get even! Price: $9.95 each postpaid LUNAR LANDER, CRAPS, GAMES PACK I and GAMES PACK II GAMES PACK I contains BLACKJACK, HORSERACE, SWITCH and more. GAMES PACK 11 contains CRAZY EIGHTS, JOTTO, ACEY-DUCEY, LIFE, WUMPUS and more. Why pay $5.95 or more per program when you can buy a DYNACOMP collection for just $9.95? All orders are processed within 48 hours. Please enclose payment with order. If paying by MASTER CHARGE or VISA, include all numbers on card. Foreign orders add 10% for shipping and handling. Write for detailed descriptions of these and other programs available from DYNACOMP. DYNACOMP, Inc. 6 Rippingale Rd. Pittsford, New York 14534 (716) 586-7579 New York State residents please add 7<7o NYS sales tax. I manage inventories is of no interest to the average child. Babies brought up in IBM computer centers will be no better at mathematics than any others. They may even be worse (and their other lapses of culture might be more disturbing). In order for computers to play the role of mathland for a child, two conditions are necessary: the computer must understand a language a child can learn (and love to learn), and the computer must be able to do something for the child. Euclidean Geometry -^ Cartesian Geometry — Computational Geometry Turtle graphics is this kind of mathland. It was first developed in our laboratory as part of the pro- gramming language LOGO and then taken over by several other languages including Smalltalk and UCSD- Apple Pascal. A lot of experience has taught us that computer graphics can be a great turn-on. People of all ages enjoy putting images on the screen, and when these images can be made to move and change color, they acquire a dimension completely lacking in conven- tional pencil-and-paper drawing. At the heart of the work on turtle graphics is the idea of developing a new kind of geometry — "turtle geometry" — which provides powerful and yet easily accessible means to manipulate shapes and motions. To put this in perspective, recall that you probably encountered at school at least two styles of doing geometry: Euclid's style (primarily logical in structure) and Descartes' style (primarily algebraic). Turtle geometry is a new style matched to the computer: it is a computational style of thinking about geometry. The difference in spirit is illustrated by how one thinks about a familiar geometric object in Cartesian and in turtle geometry. Descartes taught us to think of the circle as an equation such as: x^ + y2 = R2 In turtle geometry it is possible to use such equa- tions, but the natural way to think about a circle is as a process. To do this, turtle geometry adopts as its fundamental concept an entity called a turtle whose properties include its position (as does the point in Euclidean and Cartesian geometry) and also its heading. At any particular time, it is at a position and is facing in a particular heading. The position and the heading are changed by commands that are built into a programming language. Among these are FORWARD which causes the turtle to move in the direction of its heading without changing the heading, and RIGHT which causes the turtle to change the heading while keeping the position fixed; ie: to pivot in place. Given these commands, a program in LOGO to draw a square of a certain fixed size takes the simple form: TO SQUARE FORWARD 100 RIGHT 90 FORWARD 100... etc 234 September 1980 © BYTE Publications Inc Circle 151 on inquiry card. INFLATION FIGHTER-ROUND* 2 KO Inflation With Our Knock-Out Prices MPI 88T Impact Matrix Printer Quality, Full-Page 8'/2xl I Printout For Your Computer • APPLE II • TRS 80 • PET • ATARI • SUPERBRAIN • EXIDY • OHIO SCIENTIFIC Unrivaled champion of the small business, educational, personal computing and professional user. Quality construction and continuous duty print head allow heavy usage. Attractive styling complements the most elegant of systems without sacrificing compact size. ^ ^ ft**"" (1^ ** • Typeof Printing: Impact bidirectional 7x7 dotmatrix* Print Rate: 100 **' ,»*»* **** •: characters per second (maximum) • Thruput: 80 characters per second "** , v- (maximum) • Character Set: Full upper and lower case 96 character .^, ^•'"'^T*^.,' ASCII set, softwareselectable single ordoublewidecharacterfonts* Character "--",■''," ''^-" ^ Height: 0. 10 in. (0.25 cm) • Print Format: S.Oin. (20.3 cm) line length. 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ONLY $379 Structured Systems Call Jor Price Peachtree Call lor Price Graham Dorian Call lor Price All packages available in 8" CP/M and 5 1/4" CP/M for North Star, Micropolis, Vector Graphic. SuperBram and others. XITAN Cassette Disk ZAPPLE Monitor $25 $99 $159 $69 $69 $89 $69 $69 $249 8K Basic $50 Super Basic $95 Disk Basic ZAPPLE Text Editor $35 Z-Tel Text Editor $50 Text Output Processor $50 Macro Assembler $50 Z-BUG Micro Z-BUG LINKER Fortran IV APPLE COMPUTER & ACCESSORIES Apple II 16K or Apple lU $969 16K Memory Add-On (lor TRS-80, Exidy also) $69 Corvus 10 Megabyte Disk Drive $4650 Pascal Language System $445 Graphics Input Tablet $675 Disk II with Controller Card $495 Disk II without controller $440 Apple Soft II Firmware Card $155 Integer Firmware Card $155 Parallel Interface Card $155 Serial Interface Card $160 Communications Card $190 Sup-R-Mod FR TV Modulator $25 Sup-R-Term 80 col. 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SlOO MAINFRAMES *(incl. powersupply& motherboard) Xitan 8 Slot* List $359 $239 Calif Comp 12Slof List $400 $359 NNC 100 19Slof List $610 $540 NNC 80 8Slof List $825 $729 Space For 2 Vertical 8" Floppy Drives NNC 80 with drives List $2020 $1819 (Shugart801R) NNC 90 Dual 8" F.D. List $295 $249 NNC 90 with drives List $1495 $1339 (Shugarf801R) SIOOCOMPUTERS NNC System 80 List$3995 $3695 Dual801RDrives,Z80, 2 Serial Ports 2 Parallel Ports, 32K Static, DDFD Controller, CP/M WITH 64K Dynamic Memory List $4195 . . . $3850 WITH 64K Static Memory List $4797 $4395 DISK DRIVES ShugartSA400 5 1/4" $295 Shugart801R8" $475 ithall TERMS: Cash, check or money order, bank wire transfer, C.O.D. or credit cards. JlO.OOminimum. Charge orders must include expiration date. Purchase orders also accepted from recognized institutions. Includetelephonenumbei orders. Advertised prices are for prepaid orders. FOB. shipping point. Charge and credit orders add 2%.CODs required 25%deposit.Cahfornia residents add 6% sales tax. For shipping in U.S. add ($2.50 min.) 2% West U.S., 3% East of Mississippi, otherwise freight collect (air service where applicable). Foreign orders must be accompanied by payment in U.S. funds and include 10%for shipping. Quantities may be limited. Retail prices vary from mailorder. All prices subject to change and all offers subject to withdrawal without notice. All equipment is new with manufacturers warranty unless otherwise indicated- FALOm^ COMPUTER Call or Write For Free Catalog PRODUCTS (714) 744-7314/744-9595 910 W. San Marcos Blvd. # 105, San Marcos, California 92069 Circle 152 on inquiry card. BYTE September 1980 235 WE DELIVER! Osborne Business Sofrwore ^^? Before you buy the programs that your comparny is goirng to depernd on for its accourntirng, ask the followirng questions: Do I get the source code? Is it well documented? Is it fully supported? (Don't settle for less. You cannot make the smallest change without it.) (The Osborne documen- tation is the best.) (If not, why not? What are they afraid of?) The Osborne systenn is the industry standard accounting package, with literally thousands of users. We offer an en- hanced version of that package that will run on most systems without recompiling. CRT INDEPENDENCE. The original programs were designed to run on a Hazeltine terminal. To use a different CRT, you had to modify and test two modules — and recom- pile every program! With the Vandata package, you simply pick your CRT from a menu and run. FILE/DRIVE MAP. The original package had all data files on the same drive as the programs. Ours allows you to dynamically specify the drive assigned to each file. In fact, you can change the drive assignments whenever you wish, to ac- comodate expanded file sizes or new hardware — all without recompiling! INTEGRATION. The original AR and AP systems had to be changed and recompiled to feed journal entries to GL. Our installation program eliminates this hassle. It simply asks you if you want the systems integrated, and what your special ac- count numbers are. SPEED. The original programs used a binary search to ac- cess the GL account file. We use an enhanced technique that greatly cuts down on disk accesses, thus speeding up account lookups significantly in the GL, AR and AP systems. BUGS. We have corrected a number of bugs in the original programs. If you find a bug in our programs, we'll fix it — and send you a $20 reward] Our users are sent bug fixes in source form. MORE! We have made many minor enhancements, and fixed many minor problems. We are committed to the ongoing support of our package. Vandata has been an independent software supplier for over seven years. Quality and support are our way of doing business. General Ledger with Cash Journal $95 Accounts Receivable $95 Accounts Payable . . . $95 Payroll with Cost Accounting $95 • All Four Packages (GL, AR, AP, PR) $295 Integrated Inventory (MicroDaSys) $195 Integrated Order Entry (MicroDaSys) $195 Magic Wand(Super Word Processor!!) $345 Pearl Levellll (best prog, tool available) ... $645 CBASIC-2 $110 TRS^O MOD 1 1 CP/M 2.2 (Pickles & Trout) .. $185 H89/Z89 CP/M 2.2 (Magnolia inc. h/w mod) . $295 Formats: Std. 8", 5" NorthStar DD. TRS-80 MOD II tm, H89/Z89. Superbrain DD. Manuals for GL, AR/AP. and PR are not included in price — add $20 per manual desired (AR/AP are in one manual). CP/M and CBASlC-2 required to run account- ing software. Users must sign licensing agreement. Dealer inquiries in\/ite6. To order call: (206) 542-8370 or write: VANDATA 17541 Stone Avenue North Seattle, WA 98133 V)SA/MC Welcome — TRS-80 is a registered tm of Radio Shack, Inc. A slightly more sophisticated program to draw squares of varying size takes the form: TO SQUARE SIZE REPEAT 4 [FORWARD SIZE RIGHT 90] Now we can think of a circle as generated by: TO CIRCLE REPEAT 360 [FORWARD 1 RIGHT 1] More sophisticated programming leads to circles of variable diameter and even to letting the number of steps go to the limit, but the simple example will illustrate the main point I want to make here. Children can solve the problem of drawing a circle by using a very powerful heuristic principle: play turtle, walk out yourself what you want the turtle to do and describe what you did in turtle language. The children are practicing a lot of powerful ideas. They are exposed to the idea of using heuristic knowledge, they are learning to think of formal mathematics as rooted in (not opposed to) intuitive body- mathematics, and they are using mathematics as a language; moreover, they are learning to think about mathematics not as a ritual to be learned by rote but as an instrument to be used for personal ends. Computer as Pencil This image refers to the many uses of the pencil: it is used to scribble, to doodle, to draw, to write, to work sums, or to chew on. It is used for illicit notes as well as for official assignments. I see the computer in the life of the child as equally ubiquitous and equally versatile. I also see it as equally personal. Children own pencils, they are not intimidated by them. This should be equally true of the child's personal computer. The metaphor of the pencil is a good way to summarize some of the ways the image of the computer I am building up here differs from the one that is becoming established in schools. Suppose that the only access children had to pencils (which I take in a generic sense including pens, crayons, and the like) was at school, and even there "pencil time" had to be scheduled on the one or two pencils available to each classroom. This might (or might not) be better than having no pencils at all, but clearly under those condi- tions the pencil would not play the important role it now does in the intellectual development of children from in- fancy onwards. In my vision the computer will become as free a resource as the pencil now is. Second, there is the question of the power of the com- puter to be used flexibly for many purposes. The micro- computers in schools today can barely be used flexibly by those few who have the inclination to become virtuoso programmers in BASIC. This is very different from the model of the pencil that can be picked up by everyone — even the one-year-old infant — and also used by the most sophisticated writer or artist. LOGO and Smalltalk are only first steps toward programming languages that will truly satisfy our slogan: 'TMo threshold and no ceil- ing." A child of five or less should be able to write a pro- gram in the first few minutes of contact with the com- puter and a computer scientist should find the system congenial and rich. 236 September 1980 © BYTE Publications Inc Circle 153 on inquiry card. For your Horizon — North Star Horizon Computer with 5 " Floppy Disks Display Terminals Up To Four Hard Disks UpToFourS" Floppy Disks More power, work, flexibility! JOEDOS^'^ Jointly Operate Everything Disk Operating System Switch fronn North Star BASIC to CP/M^^ and back again with a sinnple comnnand. Floating point and standard 8, 10, 12, and 14 digit precisions of North Star BASIC, as well as Digital Research's CP/M all on the sanne hard disk unit. Designed to operate with the DISCUS M26^^ 26.5 megabyte (formatted) Winchester-technology hard disk unit and North Star's Micro Disk System, JOEDOS brings you large main- frame performance at microcomputer cost and reliability CP/M disk activity Is amazingly quick through JOEDOS; ac- cess to North Star BASIC programs and files is unbelievable! Speed and enormous storage capacity (as much as 106 megabytes) are only the beginning. Through JOEDOS, each hard disk unit may appear to be one drive or many different "drives" (as many as 147 double density 180K North Star 5V4" drive-size segments). As many as seven of these seg- mented "drives" may be addressed at any particular time. Segment size, file size and directory size are variable according to user's requirements. Maximum file size is 16 megabytes, while the maximum directory size for each seg- ment is 8,160 entries. JOEDOS — Micro Mike's hard disk operating system. Requires DISCUS M26 hard disk unit and controller and North Star Micro Disk System for operation. Includes CP/M. JOEDOS $495 JOESHARE^'^ North Star Horizon^'"/ DISCUS Hard Disk Timesharing System Micro Mike's popular interrupt-driven, bank switching time- sharing for North Star Horizon computer is now available with all the features of JOEDOS hard disk operating system. JOESHARE allows multiple users to access as many as four 26.5 megabyte hard disk units, simultaneously operating pro- grams in North Star Basic or through CP/M. JOESHARE — Micro Mike's North Star Horizon timesharing/ DISCUS hard disk operating system. Requires North Star Horizon and DISCUS M26 hard disk unit for operation. Includes CP/M. JOESHARE and manual $995 JOEDOS, JOESHARE, HDSHARE and 5.2SHARE are registered trademarks of Micro Mike's, Incorporated Horizon is a registered trademark of North Star Computers, inc. DISCUS and M26 are registered trademarks of Morrow Designs, Inc. CP/M is a registered trademark of Digital Research, Inc. Circle 154 on inquiry card. HDSHARE^'^ North Star Horizon/North Star Hard Disk Timesharing System Soon to be available, a version of JOESHARE with all of the features of JOEDOS using the North Star hard disk. HDSHARE allows multiple users to access as many as four 18 megabyte North Star hard disk units, simultaneously oper- ating programs in North Star BASIC or through CP/M. HDSHARE — Micro Mike's North Star Horizon timesharing/ North Star hard disk operating system. Requires North Star Horizon and North Star hard disk system for operation. Includes CP/M. HDSHARE and manual $995 5.2SHARE^'^ North Star Horizon/Floppy Disk Timesharing System Micro Mike's floppy disk timesharing system has some new enhancements. 5.2SHARE now supports 8, 10, 12, and 14 digit floating point and standard North Star BASIC with as many as four DISCUS 8" drives, operating in conjunction with the Horizon's SVa" drives to provide in excess of 5 megabytes of external storage. 5.2SHARE — Micro Mike's interrupt-driven, bank switching timesharing for the North Star Horizon computer Includes 8" drive software interface. For double density or quad capacity systems only. 5.2SHARE and manual $395 DOSCHG— Micro Mike's 8" drive interface to North Star DOS and BASIC. Requires North Star Micro Disk System and DISCUS 8" drives and controller for operation. DOSCHG and manual $150 Program operation manuals are available for preview before software purchase. Program Operation Manuals for each program $25 Programs are available in double density/quad capacity format only. Prices are subject to change without notice. Contact your North Star dealer or Micro Mike's cJAyUifce Micro Mike's, Inc. 905 South Buchanan Amarillo, Texas 79101 USA Telephone: 806/372-3633 making technology uncomplicated ...for People BYTE September 1980 237 WhV Your Next CRT Should Con^e From MICROMAIL: IQ120 Displays 80 x 24, upper/lower case. , Separate ni meric keypad and cursor keys. Protected fields displayed at reduced in ensity. ^^^^ «* $689.00 SOROC I • 1 1 7-key detachable keyboard with numeric cluster and cursor control. • Insert/delete line, insert/delete character. • Underline, blink, reverse, 1/2 Intensity, protected and blank fields. • Printer port with independent baud rate — prints line, partial or full $1099.00 TELEVIDEO 912/920 • Insert/delete line, insert/delete character line/page erase. • Reverse v dec, blinking, underline] V2 intensity, pro- tected fie d, blank security field. • Uses 7x10 dot matrix for a high qual ty u/l case display with descenders. • Standard typewriter or teletype keyboard; numeric keypad. • Model 920 includes 17 dedicated keys for function and editing. • Block or Qharacter transmis- sion, auxi iary printer port. • Cursor up. down, left, right, return, hofne, load, read, tab and back tab. Call for Low Price Reverse video, blinking, underline, 1 /2 intensity, protected fields, blank security field. Transmit character, line, partial page, page, or unprotected data. Cursor up, down, left, right, return, home, plus load and read. $699.00 We Also Represent the Following Manufacturers: DIABLO DEC TEXAS INSTRUMENTS ANADEX GTC TELETYPE Write or Call In for Our Free Catalogue! elilJCHQinaJJ..; MICROMAIL • BOX 3297 • SANTA ANA, GA 92703 (714) 731-4338 TO ORDER: Serd check or money order to: MICROMAIL, P.O. Box 3297, Santa Ana, CA 92703. Personal or company checks require two weeks to clear. Terminals in stock are shipped the business day after receipt of certified funds. AM equipment includes factory warranty, SHIPPING; We ship freight collect by UPS when possible. Larger terminals are shipped by motor freight.Air and express delivery is available on alt products. HANDLING: All orders are subject to MICROMAIL's handling charges. Less than $750.00, add 3%. $750.00 to $2,000.00, add 2%. Over $2,000.00 add 1%. Third, I mention the use of the pencil and of the com- puter as writing instruments. The computer is rapidly becoming the standard writing instrument. Most jour- nalists use word processors, as do increasingly many offices. I am using one as I compose this article. But the schools are not offering children this facility, although one could argue that it is children who are in most need of writing aids. The reason is clearly linked to the ratio of computers to students. One or two computers per class simply does not give enough access for the computer to become the primary writing instrument. On the other hand, one computer per child, which is how I think we should be thinking about the future, could lead to massive changes in the way children develop writing skills. A well-designed text editor makes editing — substitution and deletion of words, shifting of sentences or paragraphs, and so on — an easy and aesthetically acceptable process. Compare the situation of a child attempting such a task with paper and pencil: the mess of multiple erasures and labor of rewriting means that the first draft is almost always the final copy. I have seen children who hated writing become avid writers when they have a text editor at their disposal. Wide availability of computers with text-editing capabilities might lead to even more fundamental changes in children's relation to alphabetic representation of language. Consider the im- plications of the following story: Recently I observed the first group of nursery-school children working with a computer called the Lamplighter Computer (a Texas Instruments 99/4 per- sonal computer with additional memory to support an extended version of LOGO and a real-time text-editing system) developed over the past few years through a collaboration between our research group at MIT and Texas Instruments. A four-year-old girl (I shall call her Robin) was working with some dynamic graphics pro- grams that allowed her to make shapes appear on the screen, move, change color, and stick together by pushing one or another of some fourteen keys on the keyboard. The plan was that when Robin was tired of using a program she would ask the teacher to set up a new program. And this is in fact what she did for the first few times. But then Robin took charge of the whole process and began typing the control characters necessary to interrupt a program she no longer wanted and typing the names of the programs she did want, even though this was at a measured rate of about two characters per minute. In breaking out of the role of dependence on adults, Robin symbolized the fact that computers will enable children to break out of many of the roles into which technological primitivity and social custom have cast them. We should not pass too quickly over the significance of the simple fact that Robin could make things happen by typing words. It might well be the first time in her life that alphabetic language actually served a real and per- sonal purpose. The spoken language and its precursors enter from the first year of life into a significant process of interaction with the world. Learning to speak em- powers the child. But for most children the act of writing serves at most to gain the approval of adults. Could this be the reason children learn to talk so easily and so young Circle 155 on inquiry card. YOUR SiAART SMARTER* Automatic Date /Time Entry. Simply install the SLC-1 Time Machine between your computer and terminal and it will automat- ically log the correct date and time of each transaction into your computer. The SLC-1 Time Machine will saveyou money, both in reduced operator time and the elimina- tion of costly human errors. The Time Machine contains a preci- sion 24-hour clock and a 100-year self- correcting calendar that automatically adjust for leap years. Time and date functions include: hours, minutes, sec- onds, day, month and year. But the SLC-1 is more than a clock. It constantly monitors the out- put from any computer and provides instant responses to a number of user-defined key phrases. This makes it ideal for use with unattended process control or data acquisition systems. And since the Time Machine is a 6502 microprocessor system, it adds computing power to any terminal. The Time Machine is easily installed without modification to your operating system. Both RS-232 and 20mA current loop serial link are provided. And because it's battery-supported, the time will always be correct, even after a power failure. The single quantity price is only $640. Ten-digit display option, $190. For more information or literature on the SLC-1 Time Machine, contact Digital Pathways, Inc., 1260 L'Avenida, Mountain View, California 94043, or phone (415) 969-7600. GET INTO THE TIME MACHINE. DIGITAL PATHWAYS Circle 156 on inquiry card. BYTE September 1980 239 while they learn to write with so much difficulty so many years later? Watching Robin left me more firmly con- vinced than ever of a conjecture I have pursued for quite a few years. Children could learn to write as early and as easily as they learn to speak if th^ environment in which they lived gave as much support to the alphabetic language as ours does to the spoken language. I have no doubt that if Robin had her own computer and could use it whenever she wished, and if this computer gave her ac- cess to enough exciting things to do, she would within weeks have mastered the keyboard, the alphabet, and enough of spelling and syntax to put her firmly on the road to the kind of mastery of written language that usually comes, if at all, well into the school years. Meaning Versus Ritual in Learning The fundamental question for education is not how to improve schools but how to understand why schools are necessary. Why is some knowledge (like learning to talk) picked up so easily and naturally from the culture, while other kinds of knowledge seem to require deliberate, organized instruction? In Mindstorms I explore the many factors that make a difference. Here I have space only for one. Children learn to speak because it is a meaningful activity, a meaningful part of their lives. It is not sur- prising that children do not learn to write when writing serves no real purpose in their lives. I think the computer can change this. For Robin, alphabetic communication was beginning to become purposeful. As computers become increasingly available to children I would expect many children to share Robin's experience of writing as a meaningful activity. This shift — from meaningless ritual imposed from above to purposeful, self-directed ac- tivity — is also true of Mathland. No activity in school is experienced as more devoid of meaning than the parody of mathematics known as school math. The harm done by making children learn ritualistically goes very deep. It develops the worst possible habits of learning. It undermines the individual's self-confidence as an independent intellectual agent: it infantilizes the child. A shift to more meaningful learning of fundamental sub- jects could have far deeper consequences than improved mastery of these subjects. It could mean that children become more effective learners with greater intellectual self-respect. And if this happens, not only the nature of children's learning but also the role of children in society may have changed. I have hinted at a vision of profound, even revolu- tionary, change in how children learn. I think this might happen. We have the technology to make it possible. But there is nothing inevitable about it. Society has a very bad track record in making intelligent use of new tech- nologies, and, in this case, many vested interests are threatened by the changes I envision. The "system" will react by defending its old ways. Already in schools we see computers being used to reinforce instead of displace the most ritualistic teaching methods. I believe that the most profound effects of computers on how children learn could occur outside of schools. In fact, I think that computers would tend to make schools as we know them obsolete. But most of my "official research" is concerned with how to use computers in schools. Research funds are easily available for the reformist goals of improving schools. I believe that the most profound effects of com- puters could be to develop a new respect for children as independent intellectual agents. But most people in our country like to think of children as intellectually depen- dent. How will it all work out? It is futile for me to play pro- phet, but worthwhile to bear some ideas in mind when thinking about the future. I want to end by mentioning an idea that encouraged me to think positively. I can best introduce it by comparing the education market with markets for other products. Suppose you invent a new kind of kitchen machine. If you can prove that there is a market of a million people, you will easily find the capital to develop the idea and get it out into the world. But if you invent a new approach to learning mathematics, the fact that a million people want it may be of no avail — a million people across the nation may still be a tiny minority with no clout in every school district. But once there are a few million owners of home computers capable of carrying powerful learning methods, you will have access to a market of individuals ready to spend per- sonal dollars for the good of their children. The impor- tance of this fact is not that it will enable good ideas now collecting dust on shelves to get out into the world. It will encourage inventive and ambitious people to enter the field of educational innovation in unprecedented numbers. It will be part of the creation of a new class of professionals and of entrepreneurs and perhaps even of "stars" analogous to what happened in the course of the emergence of cinema as a culture. The history of cinema has been the history of that culture. The future of com- puters in education will be indissociable from the story of the people who will make the computer culture. ■ References For more about Turtle Geometry see S Papert, Mind- storms: Children, Computers and Powerful Ideas. New York, Basic Books, 1980 (ISBN 0-465-04627-4, $12.95). Also see H Abelson and A diSessa, Turtle Geometry, MIT Press, Cambridge MA (to appear 1981). For a bibliography of the LOGO group's internal publications, write to LOGO, c/o MIT Artificial Intelligence Laboratory, 545 Technology Sq, Cambridge MA 021 39. (Please include $1 for handling.) Editor's note: A note in the introduction to the July 1980 BYTE editorial incorrectly states that Education Forum articles by Seymour Papert and James Garson were to appear in the August and September BYTEs, respectively. However, because of unavoidable scheduling considerations, Seymour Papert' s article is appearing this month, and James Garson's article will appear in a future issue. We apologize for any in- convenience this change might have caused.... CM Education Forum is an occasional feature in BYTE intended to foster debate about the uses of personal computers in the schools and colleges. We encourage reader participation. Contributors should supply their full names and addresses for publication, along with their telephone numbers, which will not be published. 240 September 1980 © BYTE Publications Inc Circle 166 on inquiry card. Finally Serious Expansion for the AIM-65 L^ .O w^ .\A Vv ^\tv tS*- '^M" mf- :,-V.' *?»*'**w«r*'**««*jjp Introducing M«mory-Male*, the AIM-65 expansion board that lets you spend your time on application solutions, not hardware hassles. Add Memory-Mote to your AIM-65 and moke quick work of development and process control projects. In its primary function, the Memory-Mote board pro- vides 16-48K of RAM expansion assignable in 4K blocks anywhere in the system. Memory-Mote's pari- ty check circuitry insures system RAM integrity (in- cluding AIM'S 4K on-boord RAM) for high reliability applications. The programmable write protect feature eases software development chores. This compact board, which fits directly beneath the AIM, also in- cludes four programmable I/O ports, a tone generator for audible warnings, and sockets for 4K of PROM. ^ f I , Skz m I/O intensive applications ore accommodated with Memory-Mote's STD BUS interface option. Use off- the-shelf STD BUS cords to solve your biggest I/O problems. ^ The Memory-Mote with 16K RAM is priced at $475, with 1 6K expansion chip sets (including parity chip) costing $ 1 00 each. With 48-hour active burn-in and warranty for a full year, you won't hove to worry about reliability either. First of the complete AIM-Mote* series, Memory- Mate will be joined shortly by the Video-Mote*, Floppy-Mote* and the AIM-Mote cose. For further in- formation on the entire AIM-Mote series, write 'Attn: AIM-Mote Series' at the address below. *TM Forethought Products D U O CO Forethought Products 87070 Dukhobar Rd., Eugene, OR 97402 J ^ '_ (503)485-8575 t 3 O (^ O CO Q^ - **- CO -D s^ O — CO .5 o U 4- «i o v> *. ^^ - E >- "^ c :2 Khachiyan's Algorithm, Part 2: Problems with the Algorithm G C Berresford, A M Rockett, and J C Stevenson Dept of Mathematics C W Post Center, Long Island University Greenvale NY 11548 Numbering of figures, tables, listings, and equations is continued from Part 1. A paper published by the Soviet mathematician Leonid Khachiyan received widespread publicity in late 1979 as a revolutionary new solution to linear programming prob- lems. In Part 1 last month, we discussed the details of Khachiyan's algorithm and its corresponding geometric interpretation. This month in Part 2, we will look at the practical problems in using the algorithm and will ex- amine a BASIC program that uses the algorithm. A Linear Programming Example The Whiz-Golly Computer Board Company makes two kinds of video boards: the Ohwow and the Hohum. Each board is handmade by Jim and then tested by Jack. Each Ohwow board takes Jim two days to complete, while he can make one Hohum board each day. Jack can test an Ohwow board in one day, but he needs two days for each Hohum. Like most basement entrepreneurs, Jim and Jack have many other things to do with their time. Jim will not make boards for more than four days a week; Jack will test them for no more than three days a week. If the profit is two dollars for each Ohwow board and three dollars for each Hohum, how many of each should they make per week to obtain the greatest profit? This is a linear programming problem. It consists of a quantity to be maximized, the objective function, which is subject to a list of linear inequalities called constraints. If we let Xt denote the number of Ohwow boards made per week and Xj the number of Hohums made per week, the problem then is to maximize P = 2xi + 3a:2, where P is the profit per week in dollars. Since Jim cannot make a negative number of Hohums in a week, the first constraints we find are the non- negativity conditions: a:i > and X2 ^ 0. In addition, we have the constraints imposed by the number of days that Jim and Jack work per week: for Jim, we have that 2a:i + X2 < 4; while, for Jack, we have that Xi + 2;c2 ^ 3. This problem may now be written in matrix form as: to maximiz( [2 subject to [1 and ^P 1 2 "x, X2 • > [2 3] . < 'x7 X2 4 3 (7) Of course, we could have combined the two constraint equation sets into one but, as most practical problems naturally include a nonnegativity condition, we will write it separately for emphasis. The Dual Problem By a standard maximum linear programming problem we mean any problem of the form: to maximize P = c'»x subject to A»x < b and X > (8) where A is an m-hy-n matrix, b is a column vector in R"*, c is a column vector in R", and x is a column vector in n unknowns. Since Jim and Jack may wish to minimize their ex- penses, we will also encounter minimization problems. A standard minimum linear programming problem is any problem of the form: to minimize C = b'»y subject to and A'-y > y > (9) where A, b, and c are as in (8) and y is a column vector in m unknowns. 242 September 1980 © BYTE Publications Inc The two problems given by (8) and (9) are called dual problems, and their solutions are closely connected. Sup- pose that X satisfies (8) and y satisfies (9). Then c'x < (A'y)'x=y'Ax < y'b = b'y and we see that c'x < b'y for any x and y satisfying the respective constraint equa- tions. Since we wish to maximize c'x and to minimize b'y, it follows that any pair of solutions, say x and y , must satisfy c' x = b' y and conversely. To solve the pair of linear programming problems (8) and (9), we need only solve the following system of equa- tions: c'x = b'y Ax < b A'y > c x> and y > (10) The equality c'x = b'y is equivalent to the two in- equalities c'x — b'y < and — c'x + b'y < 0. The non- negativity conditions x > and y> are equivalent to — I„x < and — Uy ^ where U denotes the k-hy-k identity matrix. The condition A'y > c is equivalent to -A'y < -c. If we let z be the column vector in n-\-m unknowns formed by adjoining y to the end of x (that is, z' = (xi,...,Xr„yi,...,ym)), we can rewrite our linear program- ming problems in one giant system of inequalities: (11) where 0(j, k) denotes a j-hy-k matrix of zeros. If this system of inequalities is consistent, then the point that satisfies all the inequalities at once gives the solutions to both the maximum and the minimum problems. For our problem (7) with Jim and Jack, we see that the system (11) becomes: M ^ -^ ^n — -^ A 0(m, m) b -I„ 0(„, »■) 0(„, u 0,n. „, -A' z < — c 0,m, „ -In. Oin,, 1, c' -b' -c' b' 2 1 -1 2 -2 L -2 -1 -1 -4 4 61 4 3 -1 -2 -2 z < -3 -1 -3 3 —J I— » The solution to this problem, as we will see later, is: z = ( 12/3, V3, 1/3, IVa ) a solution that can be derived from the above matrix by use of Khachiyan's algorithm. Some General Implementation Problems As we mentioned in our discussion of Khachiyans paper his achievement of obtaining a polynomial-time algorithm is attained only by paying the price of requir- The 2nd Generation... It's something we've been Pecking away at. MEASUREMENT systems &< controls incorporated THE LOWEST prices on this high-quality software. Buy direct and save 50%. 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September 1980 © BYTE Publications Inc 243 ing an incredible level of precision in all the calculations. Moreover, his initial circle of radius 2^ can be replaced by a far smaller circle, as will be explained shortly. This does not matter to Khachiyan, since, at the initial stage of the algorithm, the precision problems are more important. The main problem we have created for ourselves is in our transformation of dual linear programming problems into a system of linear inequalities. Our statement that c'x = b'y is equivalent to the inequalities c'x — b'y < and — c'x + b'y < 0, while true mathematically, is generally false from a computational viewpoint. If we think of c'x - b'y :^ and -c'x + b'y < as "half-planes" in some n-dimensional Euclidean space (shown in figure 4 for n = 2), then it is true that they will intersect along a "line," where c'x — b'y = 0. Unfor- tunately, our computer calculations of the common points will be rounded off to a finite number of decimal places, and we should not be surprised if we cannot cor- rectly calculate a point that has zero difference between our calculated values of c'x and b'y. Our solution to this difficulty is to choose a tolerance within which we will agree that our values for c'x and b'y are essentially the same. Let e > be this tolerance. If we require that c'x — b'y ^ e and — c'x + b'y < e then we have formed a ''tube" around the line c'x — b'y = (shown for n = 2in figure 5) with width e in the direction perpendicular to x. The actual tolerance thus created will c'x— b'y =0 Figure 4 : Dissection of a plane into two half-planes by a line of the form c'x— b'y = 0. Figure 5: Dissection of a plane into two half -planes dictated by the limited accuracy of a computer. Because any computer has a limited accuracy, it is unlikely for it to compute the exact loca- tion of a point on the line c'x — b'y = 0. Instead, the line separating the two half -planes (as shown in figure 4) is replaced by a thin "tube" with a diameter less than or equal to 2e. The variable e is chosen so that a given computer can compute the location of a point that is no more than e away from a point on the center line. A 0(n., n.> ^bl -In 0(«, .) 0,., ., -A' z < — c c' -b' e — c' b' e depend on the slope of the relation c'x — b'y = relative to the X subspace. Thus our system of inequalities is no longer (11) but rather: (12) Let us now turn to the problem of estimating an initial region that will contain all solutions of the system of linear inequalities (2), from Part 1. The solutions of the systems, if any exist, form a polyhedron determined by the vertices at which the linear inequalities intersect. We can take for our initial region any sphere about the origin containing all these vertices, since such a sphere must then include some solution points of the system. The problem is then to estimate the distance to the vertex furthest from the origin. The system may be writ- ten as Ax < b where A is an m-hy-n matrix of integers and b is a column vector with m integer entries. We may suppose that m > n since we can otherwise add on ?7 — m trivial inequalities that will not change the solutions of the original system and will add only Os and Is to the matrix A. We can now compute all possible vertices of the region Ax < b by examining n rows of the equation Ax = b at a time and applying Cramer's rule. For each subset of n equations, we will find jc, = — ^, for i = l,.,.,n, where D is the determinant of the n-hy-n matrix of equation coeffi- cients and Di is the determinant of the same matrix, but with corresponding n entries of b replacing the fth col- umn of the matrix. Since we are dealing with integer coefficients, if D ^ 0, then I :r/ 1 < | D,- 1 ; and, by Hadamard's inequality, | D, | is no more than the product of the norms of the columns of the matrix in question. This now explains Qo = 2^»I„, since 2^ is greater than the product of the absolute values of all the coefficients in the system (2). We now see that an estimate better than 2^ will result if we determine the greatest possible norm for the ri-subsets of each column of A and then combine the n — 1 greatest such norms with the greatest n-subset norm from b. For example, Khachiyan's estimate for the region of (7) is 2'*'* while the above estimate based on Hadamard's inequality is 2'. The problems caused by the precision needed in com- puting the values required at each step of the algorithm appear to be nearly insurmountable. We shall not pursue this subject further than to observe its central position in the list of difficulties that prevent Khachiyan's algorithm from immediately replacing the Simplex method as the preferred method for solving linear programming prob- lems. Khachiyan's Algorithm on the TRS-80 The program given in listing 1 represents a translation of the preceding discussion into a computer program. In writing this program, we have attempted to make the translation as literal as possible for two reasons. First, we wished to study how Khachiyan's algorithm actually pro- 244 September 1980 © BYTE Publications Inc lake the mystery out of programming with the latest from BYTE Books'"^ The BYTE Book of Pascal Edited by Blaise W. Liffick Based on the growing popularity of Pascal as a programming language, numerous articles, language forums and letters from past issues of BYTE magazine have been compiled to provide this general introduction to Pascal. 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BYTE Seplember 1980 247 Listing 1 continued: 2^0 • 250 DEFDBL A » B f F f X » U f Wf Qf L 260 CLS 270 ' )K)K)K)K)K)K)K HOW TO USE THE PROGRAM )K )K )IC )K )K )K )K )K 280 INPUT-DO YOU WISH TO REVIEW THE FORMAT FOR ENTERING A PROBLEM (Y/N -- 'ENTER ) * Z V 290 IF Z$="N" THEN -^00 295 IF C%=1 THEN 300 ELSE CLStPRINT'TO DECIDE THE CONSISTANCY OF A SYSTEM OF INE QUALITIES, WRITE THE SYSTEM IN THE FORM : " : PRINTTAB( 23 ) " A)KX <> B " tPRINT "WHERE A IS A N BY N MATRIX AND B AN N-UECTOR* PRESS 'ENTER' TO BEGIN ♦" 296 Z$=INKEY$:iFZ$=- "THEN 296 ELSE ^00 300 CLS 310 print-to solue a standard linear programming problem or check tancy: ■ :print:print"1) write the problem in the form: maximize (C,x) subject to the constraints a)»cx <= b " 320 print" and x => 0" 330 print" x and c are column sectors of dimension n while b an m-uector* a is an m by n matrix. the nota- tion, (♦♦♦♦ is a standard inner product*" 3^0 print:print:print:print"hit 'enter' to continue the directions" 350 Z$ = INKEY$ t IF Z$=="" THEN 350 370 cls:print:print"2) the computer seeks a solution of the equation (cfx) = (bfy) where y is a solution of the dual* in genera l the machine cannot acheiue thisy so a tolerance f epsilon, must BE GIUEN" 380 PRINT:PRINT"3) press 'ENTER' TO BEGIN THE ALGORITHM* THE COMPUTER WILL ASK YOU FOR EACH ITEM ABOUE ♦ "* 390 Z$ = INKEY$:iFZ$:="" THEN390 -^00 CLS: INPUT"HOW MANY ROWS HAS THE MATRIX A"; M : INPUT"HOW MANY COLUMNS IN TH E MATRIX A" ; N Listing 1 continued on page 250 CONSIS IS f ♦ ♦ ♦ ♦ ) FEATURES INCLUDE: • Uses Standard Typewriter Ribbon (Model 101B-80) • Built-in Power Supply • 5 X 7 Dot Matrix Character Generator or 10 X 7 or 10 X 14 Dot Matrix • Standard 96 ASCII Character Font • Upper and Lower Case Printing • Up to 88 Characters Per Line • Single Line Print Rate Is **1 10/160 CPS • Average Print Rate Is **55/60 CPS For Ten Lines • Graphics Capability With Extended Character Modes • Programmable With 32 System Level Software Commands • Standard Parallel and Serial Interface • Reset Interface • Baudrate Select From 110 to 9600 • Manual Paper Advance (Model 101 B-80) • Manual Selftest • Adjustable Tractor Width From 1 to 972 Inches (Model 101 B-80) '*Model 101A-40 & 101 B-80 Respectively 80 COLUMN LOW COST IMPACT PRINTER $495 Kit, 101B-80KE $545 Assembled & Tested 101B-80E COOSOL, INC. 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BYTE September 1980 249 Listing 1 continued from page 248: ^10 IF C%=:2 THEN N9=:N : M9 =:M : GOTO ^30 ^20 N9==M + N : M9 = 2)K(M + N + 1) ^30 DIM A(N9rM9) rB(M9) rXl(N9) rX0(N9)rF(M9)rQl(N9rN9) rQ0(N9rN9) rU(N9rN9) rW(N9rN9) fB1(M9) ^^0 CLS: PRINT"PLEASE TYPE IN THE ROWS OF THE MATRIX A* PRESS 'ENTER' AFTER K EYING EACH NUMBER* " ^50 FOR J==.1. TO M ^60 FOR 1=1 TO N : INPUT A(IrJ) : NEXT I ^7 NEXT J ^80 cls:print"here is the matrix a* if it is not correct^ note the indices of t he miskeyed elements* press 'c to make corrections^ else hit 'enter'*" ^90 for j==1t0m : for i==l to n : print a(irj);" ";: nexti : print t nextj 500 z$=:inkey$ : if z$ :=='"• then 500 510 if z$=''c" gosub 700else 530 520 GOTO ^80 530 CLS: PRINT"PLEASE TYPE IN THE ENTRIES OF THE SECTOR Br YOU NEED "JMJ "NUMBERS * 5'^0 FOR I = 1T0M : INPUT B(I) : NEXT I 550 CLS : PRINT "HERE IS THE UECTOR B*" tFOR I==l TO M : PRINT B(I) tNEXT i: INPUT"! S IT CORRECT (Y/N)";Z$ : IF Z$=:"N" THEN 530 560 IF C%==2 THEN 730 570 cls:print"what are the coefficients of the objective function? you must s UPPLY" ;n; "NUMBERS* " 5O0 FOR I==M + 1 TO N9 : INPUT B(I) : B(I) = -B(I) tNEXT I 590 CLS: PRINT'-THE COEFFICIENTS OF THE OBJECTIVE FUNCTION ARE:" 600 FOR I = M+1 TO N9 : PRINT -B(I) : NEXT I 610 IF C%=2 THEN 730 620 INPUT"IS THE OBJECTIVE FUNCTION CORRECT (Y/N)";Z$ : IF Z$=="N" THEN 590 630 CLS: INPUT"WHAT POSITIVE NUMBER DO YOU WANT FOR THE ' TOLERANCE ' ^ EPSILON ■;B(M9-1) : B(M9)=B(M9-1) 6^0 FOR 1=1 TO N : FOR J = 1 TO M : A (N+J ,M+I )=:-A ( I ^ J ) : NEXT J t NEXT I 650 FOR I=M+N+1 TO M9-2 : A ( I-M-N r I )=-l : NEXT I 660 FOR J = l TO N : A ( J y M9-1 )= -B ( J+M ) : A ( J y M9 ) =B ( J + M ) : NEXT J 670 FOR J=:N + 1 TO N9 : A ( J r M9-1 )=-B( J-N) : A ( J y M9 )=B ( J-N ) : NEXT J 680 GOTO 730 690 STOP 700 CLS: INPUT"TO CORRECT ENTRIES IN A. ENTER THE ROW AND COLUMN INDICES OF THE ELEMENT TO BE CORRECTED " ?I y J : INPUT"NOW ENTER THE CORRECT UALUE " ; A ( J y I ) 710 INPUT'-CORRECTIONS COMPLETE (Y/N)"?Z$ : IF Z$="N" THEN 700 720 RETURN 73 CLS 7-^0 PRINT'-INDICATE YOUR CHOICE FOR THE DETERMINATION OF L FROM THE LIST BELOW: ■: print: print: PRINT" i) khachiyan's formula" : print: print" 2) h ADAMARD'S INEQUALITY ": PRINT :PRINT " 3) YOUR OWN CHOICE *" :INPUTIC% 750 ON IC% GOTO 770^20^0^760 760 INPUT "WHAT IS YOUR UALUE FOR L " ; LL : GOTO780 770 LL=:0 : FOR 1 = 1 TO N9 : FOR J = 1T0 M9 : LL = LL + LOG ( ABS ( A ( I r J ) ) +1 ) : NEXT J : NEX T I : FOR 1 = 1 TO M9: LL = LL+ LOG ( ABS (B (I ) ) +1):NEXT I : LL= LL + L0G(N9)kM9): LL = INT(LL/L0G(2))+1 780 PRINT "THE UALUE OF L FOR THIS RUN IS: "JLL 790 INPUT"DO YOU WISH TO CHANGE L (Y/N)"?Z$ : IF Z$="Y" THEN 730 800 FOR 1=1 TO M9 : B1(I)=-B(I) : NEXT I 810 FOR 1=1 TO N9 820 QOdfl) = 2 C LL 830 NEXT I 8^0 GOSUB I960: T0=MX 850 ' )MX THEN T0=MX 1^90 IF MX>0 THEN 910 Listing 1 continued on page 254 252 September 1980 © BYTE Publications Inc Circle 163 OR inquiry card. ^ REM MERGE SORT USING UNK FOR INDEX FUNCTION • MERGE (IJ=INTEGER)-iNTEGER VAR T,KM,M= INTEGER IF ARRAY (I) 0 THEN 1630ELSE K=K+1 • GOTO1620 1630 FOR I=:2 TO N9 16-^0 FOR J=:l TO N9 1650 W(JfI)=:0 1660 IF Jk 1980 ' 1990 MX=(B1(1)) : 10=1 2000 FOR 1= 2 TO M9 2010 IF BKI) > MX LET MX = B1(I) : 10 = 1 2020 NEXT I 2030 RETURN 20^0 ' @@@@@@@ THE HADAMARD INEQUALITY @@@@(3@ 2050 PN=1 : FOR KZ = 1 TO N9 : FOR J=l TO M9 : F ( J) =A ( KZ f J ) t NEXT J:MT=M9 : GOSUB 2090 : GOSUB 1010 : Bl (KZ ) =NF t NEXT KZ 2060 FOR J=l TO M9 : F(J)=B(J) I NEXT J I GOSUB 2090 I GOSUB 1010 : FOR J=1T0 N9 -1 : F(j)=Bi(j) : NEXT J :mt = N9 : gosub 2090 2070 FOR J= J. TO N9---1 : PN=PN«F(J) : NEXT J tPN = PN)kNF 2080 LL = INT(L0G(PN)KSQR(N9))/L0G(2) ) + l J GOTO 780 2090 1=1 : T=F(I) : KT=0 : K=I 2100 K=K+1 : IF K>MT LET K=I+KT I 1=1+1 : IF I > MT RETURN ELSE T=F(I) : IF K=>M T RETURN ELSE 210 2110 IF T=> r(K) THEN 2100 ELSE T=F(K) : FOR J=K TO I+l STEP -1 : F ( J ) =F ( J-1 ) : NEXT J : F(I)=T : KT=KT+1 : GOTO 2100 254 September 1980 © BYTE Publications Inc Text continued from page 246: equalities and not exponentially, as in the Simplex method. An example showing this exponential growth of the number of steps in the Simplex algorithm was con- structed in 1972 by Klee and Minty. It is interesting to see how our program reacts to this problem. We are indebted to Dr Philip Wolfe of IBM for showing us the following version of the Klee-Minty problem. Let M be given. Let c' = (10"-^ 10"-^..., 10\ 1), b' = (1, 10^ 10^...,10"^"-^^) and: A = 1 2X10^ 2X10' 1 2X10^ 2X10("-^) 2X10("-') The Simplex method takes 2" — 1 steps to find the solution of the linear programming problem (8). Running our pro- gram for Khachiyan's algorithm gave the results shown in table 1. Number of steps for Number of steps for Simplex method Khachiyan's method 1 1 35 (with 6 = .01) 2 3 525 (with e = .01) 3 7 2849 (with 6 = .01) Table 1: A short comparison of the Simplex and Khachiyan algorithms. Although this comparison strongly favors the Simplex method, Khachiyan's algorithm would be con- sistently better, given problems of a sufficiently large size. Although this data seems to reflect unfavorably on Khachiyan's method, it must be noted that this is only for small problems. Khachiyan's method would certainly re- quire less steps than the Simplex method in some real- world situations, where a typical industrial problem may involve 10,000 inequalities and 50,000 variables. Far more experience with Khachiyan's method will be re- quired to decide whether its theoretical advantage is of practical value. We wish to thank the C W Post Research Committee for providing financial support for the preparation of this article.! REFERENCES 1. Asprail, B and R E Stone, "Khachiyan's Linear Programming A\gon\hrr\," Journal of Algorithms, March 1980. 2. G^cs, P and L Lov^sz, "Khachiyan's Algorithm for Linear Pro- gramming," to appear. 3. Khachiyan, L G, "A Polynomial Algorithm in Linear Program- ming," (in Russian), Doklady, the Proceedings of the Academy of Sciences of the USSR, volume 244 (1979), number 5, pages 1093 thru 1096. 4. Kolata, G B, "Mathematicians Amazed by Russian's Discovery," Science, November 2, 1979, volume 206, number 4418. pages 545 thru 546. 5. New York Times, November 7, 11, and 27, 1979. 6. Steen, L A, "Linear Programming: Solid New Algorithm," Science News, October 6, 1979, volume 116, pages 234 thru 236. The 2nd Generation.. It's almost here! MEASUREMENT systems &v controls incorporated 867 North Main Street Orange, Calif. 92668 (714) 633-4460 here's a better way to create/edit your^orth Star basic programs Nimbus has a unique interactive GLOBAL LINE EDITOR, with powerful source preparation/editing features, unmatched anywhere at ANY PRICE! ]^ interfaces witli ANY release 4 or later BASIC by RUNning a supplied program. l^ Co-resident witli BASIC — merely type the command "EDIT" witliout a line number. i^ All N^BUS programs are assembly language fast! u^ Line scrolling plus these exciting commands: EDIT MODE • INPUT MODE • BOTTOM • TOP • BASIC • BYE • APPEND • NEXT • PRINT • COPY (lines) • DELETE (lines) • SCALE • PROMPT • CHANGE- CHANGE (global) • ERASE COLUMNS • LOCATE • LOCATE (global) • TAB • TCHAR • WINDOW -WINDOW NEXT - WINDOW PREVIOUS • VIEW • INSERT • GO (to a line) - MOVE (lines) • DEVICE N^^BUS ALSO includes BPRT, a program print/variable cross-reference utility featuring an ultra-fast shell-Metzner sort, BPAK, a source program packer and RE, a file rename program. IF YOU USE NORTH STAR BASIC, you owe it to yourself to ORDER YOUR COPY OF N^BUS today! AND ONLY ^69 64 pg. manual, alone, $9.75 ppd. — plus $1.50 postage (Creditable toward system purchase) Calif. Res. add 6% tax. No C.O.D.'s please. Send check or M.O. VISA or MASTER CHARGE accepted. Dealer inquiries invited COMPLETE BROCHURE AVAILABLE Software Systems 1269 Rubio Vista Rd. • Altadena, Ca. 91001 /^ Circle 164 on inquiry card. September 1980 © BYTE Publications Inc 255 QluCis 8(n3 Nswsletleps Connecticut H-8 Users Meet and exchange ideas with fellow Heath H-8, H-9 and H-89 users. Monthly meetings are held. For more information, contact Ron Lawson, 395 W Main St, Avon CT 06001. Z-Users Group The Z-Users Group is devoted to the Pascal/Z compiler and Z80 and Z8000 software. The pur- pose of the group is to assist the public in using, improv- ing, and exchanging soft- ware. A flyer is issued bimonthly with bug notes, fixes, and other features of interest. Public-domain pro- grams are also being distributed. A disk full of software, running under CP/M, single-sided, single density, is available free. There are no membership fees, but the flyer costs $6 per year. Contact Z-Users Group, 7962 Center Pky, Sacramento CA 95823. NICHE The Northern Indiana Computer Hobbyist Ex- change (NICHE) meets the last Monday of almost every month. Meetings are open to all computer enthusiasts. For more information, con- tact Eric Bean, 927 S 26th St, South Bend IN 46615. Upstate New York Apples The Upstate Apple Users Group meets on the third Thursday of the month at 7 PM at Upstate Computer Shop, 629 French Rd, Cam- pus Plz, New Hartford NY 13413. The group is recognized by the Interna- tional Apple Corps. The group's objectives are: to help newcomers solve hard- ware and software pro- blems, aid in resources for education and hobbyists, and investigate the use of computers in the area of the handicapped. Contact Tony Violante at the store address above. On The Source, send mail to TCC788 Attn: Tony Violante. Sol/Helios II Users ASCII is a group for users of the Sol/Helios II system, which is utilized as a business system. A quarterly newsletter is published Mmmf' M®®^®%§)m^ (l@®(a] m (o^^^^i&=#te? to APUTE.R OlRECTOR-iT V^n will tlxf Personal Compttter Exploskp tof^ YOU? Are you prepared for the explosive transformation? Right in your own home? Electronic mail. Personalized *. investment analysis. Foreign language tutorial. Home energy management. Robots. Computer music. Secretarial service. Diet and menu planning. And more, more, more. ofiCompatingT* the new McGraw-Hill quarterly, prepares you for the enormous changes coming during the u 1980 s (Some are already here), onCompttting™ explains in nontechnical language what personal computers are, how they work, and how you can use them at home, for fun and profit. Don't let the personal computer explosion catch you off guard. Know what's happening and help make it happen! Prepare now for the exciting future with a subscription to onCompfttfi^™! CaUToU-Free 800-258*5485 r k Start yoor sttbscripdon today. onComptxttog™ Subscription Dept. P.O. Box 307, Martinsville, N] 08836 DOMESTIC subscription rate: D U.S. 1 yr. (4 issues) @ $8.50 D Canada & Mexico, 1 yr. (4 issues) @ $10.00 FOREIGN (to expedite service, please remit in U.S. funds drawn on a U.S. bank.) D Europe (and all other countries, except above), 1 yr. @ $ 12.00 — surface deliveiy. D Bill Visa D Bill Master Charge D Bill me (North America only) © onComputing, Inc. 1980 Card Number Expiration Signature Name (please print) Street/Apartment Number City State/Province/Country Code 7890 Forming SuperBrain Users Group SuperBrain users who desire to exchange ideas and information should contact SuperBrain Users Group, Howard Van Jepmond, 420 French Ct, Menlo Park CA 94025. North Star Users Group Recognized by the Parent Company The International North Star Users Association (INSUA) is recognized by the North Star company to provide liaison, feedback, and fixes for users of North Star's computers or disk operating systems running on other computers. The association hopes to act as a link between local users groups, individual North Star computer users, and the Berkeley, California, com- pany. The group's charter calls for it to act as a source of information for new and advanced North Star users; to publish a quarterly newsletter for members, in- cluding application and pro- gramming techniques; to maintain and distribute a users public-domain soft- ware library; and to act as an independent represen- tative to make users' needs known to North Star Com- puters Inc. The yearly dues are $15, which includes a subscription to the newslet- ter as well as access to all the group's software and hardware distribution. INSUA can be contacted at POTOMAC MICROMAGIC.INC. 5201 Leesburg Pike, Suite 604 Falls Church. VA 22041 (703)379-9660 (VOICE) (703)379-0303 (MODEM: 300 BAUD) MEETS IEEE S-100 STANDARDS ^/ri^ AFTER ALL.. ^ALL MODEMS ARE NOT CREATED EQUAL I 131 Highand Ave, Vacaville CA 95688, (707) 448-9055. Southern Colora(Jo Computer Club The Southern Colorado Computer Club (SCCC) meets on the first and third Tuesdays of each month. Apple, Atari, Texas In- struments, and PET com- puters are among the systems represented. Classes and seminars will be scheduled for future meetings. Subjects will range from equipment hardware to programming and will in- clude information on how to go about selecting the right computer for personal or business use. Write to the club at the Computer Shack, Gibson Shopping Center, 1635 S Prairie, Pueblo CO 81005, (303) 564-3545. Evansville Computer Club This group meets at Hutch and Sons on the se- cond Wednesday of each month at 7 PM. Hutch and Sons is located on the cor- ner of Franklin and N Main streets in Evansville, In- diana. Sol, Bally, Altair, IMSAI, Heath, Elf, and TRS-80 are some of the systems used by members. Send a stamped, self- addressed envelope to Bob Heerdink, Evansville Com- puter Club, C/O National Sharedata Corporation, POB 3895, Evansville IN 47737. ■ And then there were none. The list of already extinct animals grows . . . the great auk, the Texas gray wolf, the Badlands bighorn, the sea rnink. the passenger pigeon . . . What happens if civilization continues to slowly choke out wildlife species by species? Man cannot live on a planet unfit for animals. Join an organization that's doing something about preserving our endangered species. Get involved. Write the National Wildlife Federation, Department 105, 1412 16th ' Street. MW. Washington, M3^ DC 20036. ""*' It's not too late. 258 September 1980 © BYTE Publications Inc Circle 167 on inquiry card. More from Osborne/McGravi^-Hill Osborne/ McGravi^-Hill means documented softviare FAYKOLL WITH :OST ACCOUNTING "nts Payable •^ ReceJvQbte 'c^?^?^^^': :o#?.\G: NOW AVAILABLE OSBORNE/McGraw-HiU's popular business software series in CBASIC-2! Thoroughly tested, reliable programs with complete source listings, our Payroll with Cost Accounting, Accounts Payable and Accounts Receivable and General Ledger tell you how to begin; how to make changes; how to turn your computer into a productive part of your business. Printed in a loose-leaf format, easily inserted into your own binder, you can add to the book as you add to the programs. DEALERS: The source listings from each book are available on disk for just $250 — with no licensing agreements. Call or write for our dealer information package. The books are also available in Wang BASIC. (Wang users must supply KFAM.) Z80 - 6800 - 8080A/8085 - 6502 - Z8000 - 6809 Assembly Language Programming Primers for the most popular Microcomputers New! Z8000 Available Now 6809 These Assembly Language Programming books view assem- bly language as a means of programming a microcomputer system. Each book explains assembly language program- ming, describes the functions of assemblers and assembly in- structions, and discusses basic software development con- cepts. A special section on structured programming rounds out the discussion of programming examples, which range from simple memory load loops to complete rudimentary design projects. Each book includes comprehensive coverage of the particular assembly language, and presents a large number of fully debugged, practical programming examples written in the language of interest. The 8086 Book New! A handbook for all 8086 users, The 8086 Book includes basic 8086 programming instructions, a thorough analysis of the 8086 instruction set, and detailed hardware and inter- facing guides that reveal the full power of the 8086 multiprocessing capabilities. Order Form Title Quantity Price Amount 8080A/8085 ALP S12.=.0 Z80ALP $12^0 6800 ALP $12 50 6502 ALP $12.50 Payroll with Cost Accounting - CBASIC S20 00 Accounts PavLiblc/Rcccivable - CBASIC $2000 General Ledger -CBASIC $2000 Z8000 $12.50 6809 ALP $12.50 8086 SI 5.00 Tax — Calif, residents only Tax 6%/6%% BART gj^j j^ Please send me business software information package for: '''' "^ D end user D dealer. TOTAL Shipping: (Shipping for large orders lo be arranged) n All foreign order $4.00 per book for airmail D $0.75 per book 4ih class in the U.S. (allow 3-4 weeks) n $1.25 per book UPS in the U.S. (allow 10 days) n $2.50 per book special rush shipment by air in the U.S. For faster shipment or credit card, phone (415) 548-2805 Name:, Address: , City: ZIP: , State: . C^ OSBORNE/McGraw-Hill 630 Bancroft Way, Dept. B8 Berkeley, California 94710 (415) 548-2805 TWX 910-366-7277 ^3 Circle 168 on inquiry card. BYTE September 1980 259 Event Cueue September 1980 September-October Computer Sales Workshops. Datasearch is offering one- day workshops throughout the nation covering sales techniques for managers and salespeople. For details, call or write Datasearch Inc, 4954 William Arnold Rd, Memphis TN 38117, (901) 761-9090. September-November Thinking Small — Using Small Computers to Increase Business Productivity. These conferences will feature leading authorities and small-business computer users in a program designed to explore the opportunities presented by small com- puters for the improvement of productivity in the small- business situation. For a schedule of times and places, contact The Information Ex- change, 1730 N Lynn St, Suite 400, Arlington VA 22209, (703) 521-6209. September-January Twenty-nine Seminars from DPMA Education Founda- tion. The DPMA (Data Pro- cessing Management Association) is sponsoring a series of two-day, computer- oriented seminars. Data pro- cessing, software configura- tion management, computer- aided design and manufac- turing, computers and data communications, data base, integrated circuits, and soft- ware engineering are some of the topics that will be covered. For details on site locations and times, contact DPMA Education Founda- tion Coordinator, 5959 W Century Blvd, Los Angeles CA 90045, (213) 670-2975. September 8-10 Government Micrographics Conference and Exposition, Sheraton Washington Hotel, Washington DC. This event will feature over thirty ses- sions and a major exhibi- tion. Conference topics range from micrographics to general management. Write or call National Trade Pro- ductions Inc, 9301 An- napolis Rd, Suite 206, Lanham MD 20801, (301) 459-1815. September 9-10 The Thirteenth International Symposium and Exhibition on Minicomputer and Microcomputer Applica- tions, MIMrSO, Montreal, Canada. This symposium will cover communications, signal processing, data ac- quisition, control, robotics, education, hardware, languages, networks, and FREE your keyboard — interact directly with the screen. Why waste time typing? Use a 3-G Light Pen. I In his business, Al Zenker of Zenker Denial labs in Penndel. Pennsylvania uses our pens for data entry. Harry Lee of Pitlsfteld. Massachusetts uses the pen to select telephone numbers to be dialed by his computer. Thorwald Esbensen of Micro-Ed. Inc m Min- neapolis. Minnesota writes education software for the 3-G Light Pen Swiss Air Dispatch at Kennedy Airport in New York uses our pens to speed up its bus- iness operations. Dr. Richard Kerns of East Carolina University incopor- ates our pen in a demonstration with a voice synthesizer to teach his students how to use computers. In Holland. Jo- han Smilde uses a 3-G Light Pen to experiment with graphics. I These people have discovered the be- nefits of using a 3-G Light Pen. Wouldn t a 3-G Light Pen make your system more versatile and more func- tional? Yes. of course it would' I Don't Wait — order your pen today and receive: 1) 3-G Light Pen 2) Demonstration cassettes (with Professional TRS-80. PET and Apple} 3) Sampleprogramlisting 4) Complete documentation and instructions 5) Other Light Pen software and games available. I NO ASSEMBLY NECESSARY. READY TO PLUG IN AND USE. I Complete documentation so you can write your own program in BASIC No machine languagecoding necessary I All 3-G Professional models plug into machine ports. Economy model plugs into cassette and batteries are in- cluded. ■ ^ ^ ^ ^ ■ Mail Coupon or Call Today for Immediate Delivery ■ ^ ^ ^ ^ ^ 3-G Company, Inc. Dept. BT Rt. 3. Box 28A, Gaston, OR 97119 (503) 662-4492 Yes. I want lo make my computer more versatile. Rush me Pens (Add S1 50 for maihng and handling — S6 00 foreign ) Other topics. It is being held in conjunction with the first lASTED International Sym- posium and Exhibition on Office Automation. For more information, contact Professor M H Hamza, Dept of Electrical Engineering, The University of Calgary, Calgary, Alberta, Canada I2N 1N4. September 11-13 Internepcon Semiconductor International Exposition and Conference, Republic of Singapore. Featuring an ex- hibition of production machinery, tools, hardware, materials, and test in- struments, the show in- cludes conferences keyed to the needs of engineering, manufacturing, and support personnel of Southeast Asia. It is open to all persons engaged in electronics and semiconductor manufactur- ing. Contact Industrial & Scientific Conference Management Inc, 222 W Adams St, Chicago IL 60606, (312) 263-4866. September 16-18 Euromicro '80, London, England. Euromicro '80 will consist of scientific, short- notes, and industrial ses- sions. This annual inter- national event is highlighted by read papers and discus- sions. In addition, micropro- cessor-controlled robot mice will race against time or will show off their prowess in an "open world" environment when the European finals of the Amazing Micromouse Maze contest are held. For information, contact Lionel R Thompson, HSDE, Hat- field AL 109LP, England. September 16-18 Wescon/80, Anaheim Con- vention Center, Anaheim CA. This year's show will include a large exhibition and a variety of talks cover- ing communications, com- puters and microprocessors, consumer electronics, energy, office automation 260 September 1980 © BYTE Publications Inc Circle 169 on inquiry card. CP/M* compatible software SYSTEM MAINTENANCE- DIAGNOSTICS I: Easily the most comprenensive set of CP/M compatible system check-out programs ever assembled. Finds hardware errors in your system, confirms suspicions, or just gives your system a clean bill of health. Tests. • Memory • CPU (8080/8085/Z80) • Terminal • Disk • Printer To our knowledge the CPU test is the first of its kind anywhere. Diagnostics I can help you find problems before they become serious. A good set of diagnostic routines are a must in any program library. Minimal requirements: 24K CP/M. Supplied with complete user manual: $60.00 Manual alone: $15.00. ACCOUNTING : A complete, user oriented package invoice aging customer statements invoice aging ACCOUNTS PAYABLE/RECEIVABLE: which features: automatic postings to general ledger (optional) accounts payable: • check printing with invoice accounts receivable: • progress billing • partial invoice payments The entire package is menu driven and easy to learn and use. It incorporates error checking and excellent user displays. This package can be used stand alone or with the General Ledger below. Supplied with extensive user manual: $200.00. Manual alone: $20.00. GENERAL LEDGER: A complete, user oriented package which features: • Accepts postings from external programs (i.e. AP/AR above) • Accepts directly entered postings • Maintains account balances for current month, quarter, and year and previous three quarters • Financial reports: trial balance, income statement balance sheet, and more. Completely menu driven and easy to learn and use. Excellent displays and error checking for trouble free operation. Can be used stand alone or with Accounts Payable/Receivable above. Supplied with extensive user manual: $200.00. Manual alone: $20.00. Both require 48K CP/M, terminal with cursor positioning, home and clear home, one 8" disk or Two 5" disks. CBASIC2 required. TEXT PROCESSING- More TFS-Text Formatting System: An extremely powerful formatter, than 50 commands. Supports all major features Including: • lefts right margin justification • user defined macros • dynamic insertion from disk file • underlining and backspace TFS lets you make multiple copies of any text. For example: Personalized form letters complete with name & address & other insertions from a disk file. Text is not limited tothe size of RAM making TFS perfect for reports or any big job. Text is entered using CP/M standard editor or most any CP/M compatible editor. TFS will link completely with Super-M-List making personalized form letters easy. Requires: 24K CP/M. Supplied with extensive user manual: $85.00. Manual alone: $20.00. Source to TFS in 8080 assembler (can be assembled using standard CP/M assembler) plus user manual: $250.00. MAILING LIST SUPER-M-LIST: A complete, easy to use mailing list program package Allows for two names, two address, city, state, zip and a three digit code field for added flexibility. Super-M-List can sort on any field and produce mailing labels direct to printer or disk file for later printing or use by other programs. Super-M- List is the perfect companion to TFS. Handles 1981 Zip Codes! Requires: 48K CP/M. Supplied with complete user manual: $75.00. Manual alone: $1 0.00 UTILITIES Utility pack #1: A collection of programs that you will find useful and maybe even necessary in your daily work (we did'). Includes: CMP: Compare two files for equality Compacts many files into one. useful when you run out of directory entries. In core sort of variable length records. Extended, alphabetical directory listing with groupings by common extension Formatted listings to printer. Lists files to CRT a page at a time. . . . plus more . . Requires: 24K CP/M. Supplied with instructions on discette: $50.00. Circle 170 on Inquiry card ARCHIVER: SORT: XDIR: PRINV PC: -PROGRAMMING LANGUAGES FORTH: a full, extended FORTH interpreter/compiler produces COMPACT, ROMABLE code. As fast as compiled FORTRAN, as easy to use as interactive BASIC. • SELF COMPILING: Includes every line of source code necessary to recompile itself. EXTENSIBLE: Adds functions at will. Z80 & 8080 ASSEMBLERS included Single license, OEM licensing available Please specify CPU type: Z80 or 8080 Supplied with extensive user manual and tutorial: $150.00 Documentation alone: $25.00 ENHANCED 'TINY' PASCAL: We still call it 'Tiny' but its bigger and better than ever' This is the Famous Chung/Yuen 'Tiny' Pascal with more features added. Features include: • recursive procedures/functions • integer arithmetic • CASE • FOR (loop) 'Sequential disk I/O • one dimensional arrays • IF . . . THEN . . , El SE -WHILE ' 'PEAK' & 'POKE' •READS WRITE -REPEAT ... UNTIL -more Tiny' Pascal is fast. Programs execute up to ten times faster than similar BASIC programs. SOURCE TOO' We still distribute source, in Tiny' Pascal, on each discette sold. You can even recompile the compiler, add features or just gain insight into compiler construction. Tiny' Pascal is perfect for writing text processors, real time control systems, virtually any application which requires high speed. Requires: 36K CP/M. Supplied with complete user manual and source on discette: $85 .00. Manual alone: $10.00. SOFTWARE SECURITY ENCODE/DECODE: A complete software security system for CP/M. Encode/ Decode is a sophisticated coding program package which transforms data stored on disk into coded text which is completely unrecognizable, Encode/Decode supports multiple security levels and passwords. A user defined combination (One billion possible) is used to code and decode a file. Uses are unlimited. Below are a few examples: • data bases • general ledger • inventory • payroll files • correspondence • accounts pay/rec • programs • tax records • mailing lists Encode/Decode is available in two versions: Encode/Decode I provides a level of security suitable for normal use. Encode/Decode II provides enhanced security for the most demanding needs Both versions come supplied on discette and with a complete user manual. Encode/Decode I: $50.00 Encode/Decode II: $100.00 Manual alone: $15.00 — INTERCOMPUTER COMMUNICATIONS TERM: a complete intercommunications package for linking your computer to other computers. Link either to other CP/M computers or to large timesharing systems. TERM is comparable to other systems but costs less, delivers more and source is provided on discette' With TERM you can send and receive ASCII and Hex files (COM too, with included convertion program) with any other CP/M computer which has TERM or compatible package. Allows real time communication between users on separate systems as well as acting as timesharing terminal, • Engage/disengage printer • error checking and auto retry •terminal mode for timesharing between systems -conversational mode •send files • receive files Requires: 32K CP/M. Supplied with user rnanual and 8080 source code: $110,00 Manu al alone: $15.00. CP/M Formats: 8" sort sectored, 5" Northstar, 5" Micropolis Mod IL Vector MZ ^^^^ All Orders and General Information: SUPERSOFT ASSOCIATES P.O. BOX 1628 CHAMPAIGN, IL 61820 (217)359-2112 Technical Hot Line: (217) 359-2691 VISA master criarge ^1JTiP r^ (jft (answered only when technician is available) / / 'CP/M REGISTERED TRADEMARK DIGITAL RESEARC First in Software Technology BYTE September 1980 261 and semiconductor technology, and more. Con- tact Wescon, 999 N Sepulveda Blvd, El Segundo CA 90245, (213) 772-2965. September 17-19 ACM Small/Personal Com- puter Conference, Rickey's Hyatt House, Palo Alto CA. This symposium will blend contributed papers, panel, and informal discussions. Hardware and software topics involving theory, design, construction, marketing, and application will be included. Discussions will cover microcomputer applications in business, in- dustry, education, and the home. Details are available from Conference Chairman, Philippe Lehot, PLA, 976 Longridge Rd, Oakland CA 94610. September 18-21 Mid- Atlantic Business and Home-Computer Show, DC Armory / S tarplex , Washington DC. This is an end-user exposition featuring small- and medium-sized business systems, scientific and engineering computers, microcomputers, and electrotechnology. Contact Northeast Expositions Inc, POB 678, Brookline Village MA 02147, (617) 739-2000. September 22-25 Software INFO, Hyatt Regency, Chicago IL. This is the first national conference and exhibit on packaged software held in the US. For more information, or to reserve space, call (312) 263-3131 or write Soft- ware INFO, Suite 545, 222 W Adams St, Chicago IL 60606. September 23-25 Compcon '80 Fall, Capital Hilton Hotel, Washington DC. Sponsored by the IEEE (Institute of Electrical and Electronics Engineers), this show is concerned with distributed computing and related topics. Discussions will cover interfaces, stan- dards, and protocols; data communications and net- working; computer systems; data bases; security; office systems; and more. Details from Compcon '80 Fall, POB 639, Silver Spring MD 20901, (617) 879-2960. September 24-27 The Tenth Annual Con- ference of the Society for Computer Medicine, San Diego Hilton, San Diego CA. This conference has been planned for physicians, attorneys, administrators, computer professionals, comptrollers, engineers, nurses, and anyone in- terested in the use of com- puters for patient care. Ses- sions on medical subjects, technical subjects and con- tributed papers on new research in computer medicine will be offered. For information, contact Society for Computer Medicine, 1901 N Ft Myer Dr, Suite 602, Arlington VA 22209, (703) 525-0098. September 25-28 Mid-Atlantic Personal and Business Computer Show, Philadelphia Civic Center, 65000/ The MJniFramt' is here and MicroDaSys has it! Now you can own a complete minicomputt^r featuring the incredible power of the 6800t processor in a versatile turn-key system - all at micro prices! The 68000 processor offers a 16 bit external and M bit internal dMa path, rind has many architectural features previously found oniy in mainframe computers. The MDGJiK single board computer offers the user all of the power of the 68*00 in a complete minicomputer, combining mass memory , double density disk/Winchester controller, interrupt architecture, and multi-user I/O The MD68K may easily be interfaced to a variety of bus adapters, allowing the use of external peripherals, and RAM expansion to 16 Megabytes. The MiniFrame houses the MD68K, power supplies, I/O connectors and dual eight inch drives. Whether you are looking for the most advanced single board computer, or an amazing turn-key system, the MD68K and MiniFrame are for you! ~ Hardware: 256K Bytes RAM Parity Checking Memory Management Sophisticated Firmware 8 Parallel Ports 8 RS-232 Serial Ports Double Density Controller Winchester Controller Dual 8" Floppies Multi-User, Multi-Tasking Winchester Option Bus Adapters Available: IEEE 488 S-100 Intel SS50 DEC etc. Software: DOS Resident Assembler Cross Assembler Linker Debugger Pascal BASIC etc. MD68K Single Board Computer $2395 MiniFrame'with Dual Drives $3995 How To Order: MicroDaSys By Phone: Call (213) 731-0876 for VISA, MC and COD. By Mall: Send check or money order. P.O.(3ox 36275 , Los Angeles , CA yt>l)lb TWX: 'J 10-:52 )-2378 Philadelphia PA. General admission for adults is $5. The show is being produced by National Computer Shows, POB 678, Brookline Village MA 02147, (617) 739-2000. September 25-29 The Third World Computer Chess Championship, Brucknerhaus, Linz, Austria. This tournament will be a four- or five-round Swiss- style competition with par- ticipants restricted to com- puter chess programs. The current world and North American champion, CHESS 4.9 of Northwestern Univer- sity, will return to defend its title. Also expected to par- ticipate are the former world champion, KAISSA, from the Moscow Institute of System Studies; MASTER, the current European cham- pion; BELLE, CHAOS, DUCHESS, and other pro- grams from Europe, the US, and Canada. For informa- tion in the US, contact Pro- fessor M M Newborn, School of Computer Science, McGill University, Montreal, Quebec H3A 2K6 Canada. In Europe, contact Frederic Friedel, Haupt- strasse 28B, 2114 Hollenstedt, West Germany (BRD). September 26-27 Classroom Applications of Computers in Grades K thru 12, Independence High School, San Jose CA. Tutorials, workshops, ex- hibits, and a trip to "Silicon Valley" will highlight this conference. The emphasis will be to inform teachers about the possible uses of computers in all areas of education. Contact Computer-Using Educators, c/o W Don McKell, In- dependence High School, 1776 Educational Park Dr, San Jose CA 95133. September 30-October 2 Computer Crime: Investiga- tion and Prosecution, San Francisco CA. This workshop is designed for security and law enforce- ment investigators, prose- cutors, attorneys, and com- puter specialists who have 262 September 1980 © BYTE Publications Inc Circle 171 on inquiry card. ._teii iiiil^^ L CompuServe's information service. A world of information available. Right now. If you have a personal computer — or a computer terminal — CompuServe can bring a world of information into your home or small business. CompuServe CompuServe is a major computer services com- pany that has been serving top industrial and governmental clients for more than a decade. Now we're also applying our extensive computing capacity to the delivery of information services to your personal computer. The Information Service This exciting service is available in more than 250 cities between 6 p.m. and 5 a.m. weekdays, all day weekends and most holidays. Cost? Only $5.00 per hour billed in minutes. All you need is a 300 baud modem, and our complete information service is only a local phone call away. Welcome to CompuServe's information service. • News. Weather. Sports. Major regional news- papers. Plus international news services. • Finance. MicroQuote. Updates and historical information on stocks, bonds and commodities. • Entertainment. Theatre, book, movie and res- taurant reviews. Plus opera, symphony, ballet, dance, museums, galleries... • Electronic Mail. Create, edit, send and receive messages from any other CompuServe user... nationwide. • Home & Educational Reference Service. Any- thing you want to know . . . from encyclopedia in- formation to household tips. • CompuServe User Information. In case you need technical help ... and information on new services as they become available. • MicroNET. For the computer hobbyist. Software Exchange, line printer art gallery, challenging games, programming languages, word proces- sing, business & educational programs ... and much, much more. And this is just the beginning. CompuServe is continually adding to its list of available services. The world of electronic information isn't coming tomorrow. It's here today. CompuServe is Available at Radio Shack® Stores Your local Radio Shack® Store Sells Com- puServe's information service. There are more than 6,000 Radio Shack® Stores and Dealers nationwide. Check with the outlet nearest you. Radio Shack is a division of Tandy Corporation. CompuServe Information Service Division 5000 Arlington Centre Blvd. Columbus, Ohio 43220 (614) 457-8600 Circle 172 on inquiry card. BYTE September 1980 263 had training or experience in investigating financial or computer crimes. The fee is $575. For more information, contact Paul Shaw, Assets Protection Journal, 500 Sut- ter St, Suite 503, San Fran- cisco CA 94102, (415) 392-2955. October 1980 October 1-2 Choosing and Using Microprocessor Develop- ment Systems, London Press Centre, London, England. This seminar will present in- formation and practical ex- perience on which to base the selection and use of microprocessor-development systems. It will provide guidelines to answer ques- tions on the definition of microprocessor-development systems, what features should be looked for, how to analyze particular re- quirements, and what systems are commercially available. The program is intended for senior engineers and engineering managers who have some knowledge of microprocessors. Contact the Conference and Courses Unit, Sira Institute Ltd, South Hill, Chislehurst, Kent BR7 5EH, England. October 1-3 The Tenth International Symposium on Fault- Tolerant Computing, Kyoto, Japan. This meeting is devoted to the theory and practice of reliable com- puting and will cover design of fault-tolerant circuits and systems, analysis of system performance and reliability; D-Catr ^. -)]))^' Everything ~^^ yoiill ever need in a basie, direet modem. There's only one originate /answer modem that gives you the performance and reliability of a direct connect modem with the portability and price of an acoustic. Novation's new D-Cat. D-Cat is the only direct modem that's FCC approved for handset jack connection with any modular phone. Use it at home or at work on a 50-pin, six line business phone. Talk to D-Cats, Cats, or any other Bell 103 compatible modem. D-Cat also has all the features you want: full duplex capability, voice/data 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 monitor, up to 20 dB performance improvement over acoustic, hold function, privacy button, self -test, and a remarkable price. Only $199. But best of all, it's from Novation. The recognized world leader in personal communications. D-Cal.by Novation Call for details: (800) 423-5410 In California (213) 996-5060 applications of coding tech- niques, software reliability and testing, and more. For information and traveling arrangements, contact Secretary of FTCS-10, Dept of Applied Mathematics and Physics, Faculty of Engineer- ing, Kyoto University, Kyoto 606 Japan. October 6-8 APL Users Meeting, Toron- to, Canada. This conference is aimed at APL users as well as those considering the use of APL in their systems. Speakers will present papers which discuss the practical use of APL. Managing APL resources, teaching APL, and APL programming techniques will also be covered. The registration fee is $180 (in Canadian funds), which includes a copy of the proceedings. For a brochure and registration material, contact Rosanne Wild, I P Sharp Associates Ltd, 145 King St W, Toronto, On- tario, M5H 1J8, Canada. October 8-10 Circulation Computer Systems Symposium, Chicago Marriott Hotel, Chicago IL. More than 425 newspaper publishers, general managers, circula- tion directors, controllers, and data-processing managers are expected to at- tend this symposium. Workshop sessions will be held for participants who already have or who are considering automated cir- culation systems. For more information, contact American Newspaper Publishers Association, The Newspaper Center, POB 17407, Dulles Airport, Washington DC 20041, (703) 620-9500. October 14-16 Minicomputer and Microcomputer Conference and Exposition, Brooks Hall/Civic Auditorium, San Francisco CA. Contact Managing Director, Mini/Micro Conference and Exposition, 32302 Camino Capistrano, Suite 202, San Juan Capistrano CA 92675, (714) 661-3301. 264 September 1980 © BYTE Publications Inc Circle 174 on inquiry card. stack Work's A full, extended FORTH interpreter/compiler produces COMPACT. ROMABLE code. As fast as compiled FORTRAN, as easy to use as interactive BASIC. SELF COMPILING Includes every line of source code necessary to recompile itself. EXTENSIBLE Add functions at will. CP/M* COMPATIBLE Z80 & 8080 ASSEMBLERS included Single license \ Supplied with extensive user manual and tutorial: \\ $150.00 Documentation alone: $25.00 OEM's, we have a deal for you! CP/M Formats: 8" soft sectored, 5 Northstar, 5" Micropolis Mod II. Please specify CPU type Z80or8080 All Orders and General Information: SUPERSOFT ASSOCIATES RO. 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 *CP/M registered trademark Digital Research Circle 173 on inquiry card. BYTE September 1980 265 Circle 175 on inquiry card. Disc/3 MART, INC. DO IT YOURSELF LOUV-LOUV PRICES ANADEX PRINTER, DP-8000 $ 825.00 ANADEX PRINTER, DP-9500 1,425.00 BASE II Printer (complete with options) 645.00 CENTRONICS 737 Matrix Printer 825.00 HAZELTINE 1520 1,319.00 NEC Spinwriter 5510 (RO) 2,643.00 SOROC IQ 120 745.00 SOROC IQ 140 Assembled 1,225.00 Tl 810 Basic (upper & lower case) 1 ,669.00 Tl 994 Personal Computer 925.00 LA 34 DEC Writer Teleprinter 1,195.00 CARTRIDGES • DISKETTES • MAG TAPE • ACCESSORIES ADDS, CENTRONICS, HAZELTINE, IMSAI, LEAR SIEGLER, TECHTRAN, Tl, VECTOR GRAPHICS AND OTHERS STORE HOURS: 9 A.M. -5:30 P.M. Mon. through Fri. Ca[l or write for quotes or information. Circle 129 on inquiry card. 1840 LINCOLN BLVD., SANTA MONICA, CA 90404 (213) 450-5911 Disc/3 MART, INC. Marymac Industries Inc Radio /haek AUTHORIZED SALES CENTER Save 10% 15% OR MORE ► < DELIVERED TO YOUR DOOR Owned and operated by Marymac Industries Inc. Houstons only independent Radio Shack® dealer. Warranties will be honored by all company owned Radio Shack® stores and most franchise and dealer authorized sales centers. Store open Mon.-Sat. 10-7. We pay freight and insurance. Save state sales tax, Texas residents add only 5% sales tax. Brand new in factory sealed cartons. Reference: Katy National Bank. Call us for a customer reference near your city. Offered ex- clusively by Radio Shack® Authorized Sales Center 21969 katy Fwy., Katy (Houston) Texas 77450 Telephone 1-713-392-0747 TRS-80 FOR BUSINESS, LEARNING AND ENTERTAINMENT cciiil Limited Time Otily lisk Drive . . $349.90 Delivered. (Cai.#26-1160. 26 1 161) Meet TRS-80's Big Brother! The NewTRS-80 Model II We are located just 5 hours from the giant Tandy Com- puterware House in Ft. Worth, Texas. Call |oe McManus We've added a bigger, more powerful 'brother" to the TRS-eO family it's TBS-eO Model II — a completely new microcomputer lor business applications Today CHARGE IT /haek October 16-19 Midwest Personal and Business Computer Show. For more information on this exposition, contact National Computer Shows, FOB 678, Brookline Village MA 02147, (617) 739-2000. October 26-28 The Eleventh ACM North American Computer Chess Championship, Opryland Hotel, Nashville TN. This is a four-round Swiss-style tournament with par- ticipants restricted to com- puters. All of the best chess programs in North America are expected to participate. A maximum of twelve teams will participate. The deadline for entries is September 8, 1980. Contact Monty Newborn, School of Computer Science, McGill University, 805 Sherbrooke St W, Montreal, PQ, H3A 2K6, Canada, (514) 392-8274. October 26-29 International Data- Processing Conference and Business Exposition, Philadelphia Sheraton Hotel, Philadelphia PA. This con- ference is being sponsored by the Data Processing Management Association. Contact the Conference Coordinator, DPMA Inter- national Headquarters, 505 Busse Hwy, Park Ridge IL 60068, (312) 825-8124. October 27-29 ACM Annual Con- ference — Previewing the Computer Age, Opryland Hotel, Nashville TN. This conference will focus on the computer technology, prod- ucts, and services that will come into general use during the 1980s. The technical pro- gram will be organized around the Association for Computing Machinery's (ACM) Special Interest Groups, with additional ses- sions for papers of general interest. Contact Dr Gordon Sherman, Technical Pro- gram Chairman, ACM '80, University of Tennessee Computer Center, Knoxville TN 37916, (615) 974-6758. October 27-30 The Fifth International Con- ference on Computer Com- munications, Peachtree Plaza Hotel, Atlanta GA. The theme for ICCC/80 is "Computer Communica- tions: Increasing Benefits for Society." More than one hundred speakers will pre- sent papers on applications and technical developments of computer communication and assess their worldwide implications for the 1980s. Fees are $175 for pre- registration and $200 at the conference. Contact ICCC/80, POB 280, Basking Ridge NJ 07920, (201) 221-8800. October 28-30 The Fourth Annual Interface West, Los Angeles Conven- tion Center, Los Angeles CA. More than one hundred fifty computer-related com- panies will exhibit their wares. The conference will offer programs on office automation and small- systems procedures for businessmen, plus data com- munications, distributed- data processing, and net- working for technically oriented managers. Many speakers will be featured. For further information, contact The Interface Group, 160 Speen St, Fram- ingham MA 01701, (617) 879-4502 or call toll free, (800) 225-4620. October 30-November 1 National Small-Computer Show, New York Coliseum, New York NY. Hourly lec- tures on data-processing and word-processing applications for small computers, exhibi- tions of hardware and soft- ware, and seminars on various aspects of computer- related news will be featured. A lecture schedule and basic information are available from the National Small Computer Show, 110 Charlotte PI, Englewood Cliffs NJ 07632, (201) 569-8542. NOVEMBER 1980 November 8-9 The 1980 Personal Com- puter Fair, Pacific Science 266 September 1980 © BYTE Publications Inc Circle 176 on inquiry card. Here's The Second Half Second Edition $1595 (soft cover) Written by the author of your Level II Users Manual, LEARNING LEVEL II picks right up where the Level I Manual leaves off. It even supplies the changes needed to make the Level I Manual compatible with your Level II TRS-80. LEARNING LEVEL II covers all Level II BASIC beyond Level I, plus much more. It shows you how to use the Editor, explains what the many error messages are really saying, and leads you thru conversions of Level I programs to Level 11. Dual cassettes, the Expansion Interface with Real Time Clock, use of printers and other features are explained in the same easy-to-learn style that made the Level I Manual famous. LEARNING LEVEL II was created specifically for your Level II TRS-80! I I I I Yes, I want to LEARN Level II ! COMPUSOFT® PUBLISHING • 1050 E B Pioneer Way • El Cajon, CA 92020 (714) 588-0996 NAME Please send. copies of LEARNING LEVEL U. My check for $15.95 each + $1.45 P&H is enclosed. (CA addresses add 6% sales tax). 1 understand my order will be shipped promptly and there is a 30 day money-back guarantee. ADDRESS CITY STATE. ZIP CODE. I I I i Circle 358 on inquiry card. BYTE September 1980 267 Circle 177 on inquiry card. Start Small and Grow Big with our expandable multi-processor, multi-user system S100 Bus and CP/M 2.2® Compatible Hardware Features 1. Each user has its own complete system con- sisting of CPU. memory, console & local printer 2. Unlike MP/M* system there is no console speed degradation as you add users 3 All users share common disk storage and host printer, 4 Users can select either host or local printer 5. Up to 128 user terminals can be connected 6 S-100 Bus compatible. 7 Each user has a hardware CPU reset button If any of the users "crash" he can reset his CPU 8. Interfaces to IBM3101 and other terminals Software Features 1 . Use of CP/M 2.2 ailowsany CP/M compatible softwares to be used, 2 DPOS/2 multi-user supervisor executive. 3 2 file protect modes (in addition to CP/M's) prevent "fatal embrace" and "interleaved update sequences." 4 Automatic host printer spooling 5 Messages can be passed among users. OoM Computer Corporation 2364 Walsh Ave. Santa Clara, CA 95051 (408) 496-6910 MARK GORDON COMPUTERS DIVISION OF MARK GORDON ASSOCIATES, INC. 15 KENWOOD ST., CAMBRIDGE, MASSACHUSETTS 02139 (617) 242-2749 (617) 491-7505 SD SYSTEMS COMPUTER KITS * EXPANDORAM I (No RAMS) 169.00 * VERSAFLOPPY CONTROLLER I . . 189.00 * SBC-100 Single Board Kit 239.00 * Z80 Starter 269.00 OTHER SPECIALS * 16K Memory Kit 59.00 * CAT Modem 159.00 * Leedex Monitor 109.00 * Atari 400 499.00 * Atari 800 779.00 * Hazeltine 1410 699.00 CALL COLLECT TO ORDER ORDERING INFORMATION We accept Visa and Mastercharge. We will ship C.O.D. certified check or money order only. All orders must include 4 percent for shipping and handling. Massachusetts residents add 5 percent sales tax. The Company cannot be liable for pictorial or typographical inaccuracies. Center, Seattle WA. The theme of this year's fair is "Hands On." The booths and exhibits will reflect this idea, and the public will have access to as many com- puters and terminals as possible. Contact the Northwest Computer Soci- ety, POB 4193, Seattle WA 98119, (206) 284-6109. November 10-14 The Fourth Annual Data- Entry Management Con- ference, Orlando FL. This conference will cover data entry, distributed process- ing, and word processing with emphasis on data entry, including human- machine interface. Contact Data Entry Management Association, POB 3231, Stamford CT 06905, (203) 322-1166. November 18-20 The Third Industrial Revolu- tion, McCormick Place, Chicago IL. This exposition and conference is devoted to development by manufactur- ing companies of systems for information management. Information may be ob- tained from Banner & Grief Ltd, 110 E 42nd St, New York NY 10017, (212) 687-7730. November 19-21 Comdex '80, Las Vegas Con- vention Center, Las Vegas NV. Comdex is a conference and exposition for indepen- dent sellers of small- computer and word- processing systems, peripherals, media, and sup- plies. Address inquiries to the Interface Group, 160 Speen St, Framingham MA 01701, (800) 225-4620, in Massachusetts call (617) 879-4502. November20-21 Western Educational Com- puting Conference, San Diego CA. This seminar will feature papers and seminars on the use of computing in higher education for instruc- tion, administration, and research. Contact Ron Langley, Director, Computer Center, California State University, Long Beach, 1250 Bellf lower Blvd, Long Beach CA 90840, (213) 498-5459. November 20-23 Northeast Personal and Business Computer Show, Hynes Auditorium, Boston MA. This is an annual ex- position open to the general public. The admission will be $5. Contact National Computer Shows, POB 678, Brookline Village MA 02147, (617) 739-2000. November 21-23 National Home Entertain- ment Show, New York Col- iseum, New York NY. Ex- hibits will cover video, photography, audio, games, and home computers. Seminars and demonstra- tions will be featured in this show. Contact United Business Publications Inc, 475 Park Ave South, NewYork NY 10016, (212) 725-2300. ■ evTE^eugs An Error in Fifteen I enjoyed seeing my article "Fifteen: A Game of Strategy" appear in the June 1980 BYTE (page 230). Un- fortunately a bug crept into the program (listing 1), and it will not run as listed. The problem is in line 720, which should read: "IFT2>0THEN750" rather than "IF T2>0 THEN 270". With this change it runs as it should. If the EXIT statements are dropped and the PRINT statements changed, then the program runs very nicely on a TRS-80 under Level II BASIC. John Rheinstein 10 Gould Rd Lexington MA 021731 268 September 1980 © BYTE Publications Inc Circle 178 on inquiry card. Circle 180 on inquiry card. ATTEXTIOX COMMODORE DISK OWNERS Never sort another disk file! With Creative Software's ISAM file handling routine, your files are always maintained in sorted order. 2K bytes of assembly language subroutines allow you to: • CREATE a new ISAM file • OPEIN an existing file • READ key and data from file • WRITE key and data to file • READINEXT key and data from file • DELETE key and data from file • CLOSE file • SUPPORTS up to 5 open ISAM files simultaneously Available for 16K or 32K CBM tompulera and 2040 disk units S99.95 + S2.50 shipping Soon to be available for CBM 8016 and 8032 computers with 8050 disk drive. Manual available separately for S15.00 Creative Softurare P.O. BOX 4030, MOUNTAIN VIEW, CA 94040 ***********************************^ SURPLUS "SELECTRIC" SPECIAL! "SELECTRIC ' TYPEWRITER TERMINAL Just imagine; an IBM Model 725 "SELECTRIC" typewriter built into a complete table-top RS-232 terminal! These surplus terminals were formerly on lease and appear to be in good condition (we test 'em to make sure the printer is functional]) These fantastic BCD-Coded terminals feature: 134.5 BAUD I/O 88 Character Set 6 Bit BCD CODE Attractive Case Upper/Lower SHIFT ONLY •15" CARRIAGE •725 'SELECTRIC • RS-232 I/O • 132 COLUMNS • Sim. to IBM 2741 • Std. Typewriter Kbd. •MAX: 15 CPS RATE • 10 Chars./lnch • Removeable Type Sphere While we will check out each unit, we MUST offer these unique bargains "AS-IS": Meaning they may need some service but are basically operational. Add $20.00 for packing crate, you pay shipping on delivery. ALSO INCLUDES: Type ball. I/O circuit boards, power supply & some data. Sorry, no power cord included. -SPECIAL OFFER!!- Buy 2, take 20% Off the Full Price— o for «^ K r\f\f\ You Pay Only ^ ^^^ " 5 0"° "SELECTRIC"* PRINTER MAINTAINANCE MANUAL JUST IN!! We now have available some excellent printer maintainance manuals. These are the most thorough manuals we've seen. Well worih ihe price! ONLY '25.00ea. ' 'SELECTHIC'- IS an IBM Trademark CFR Associates, Inc. MAIL ADDRESS: WAREHOUSE: |617l3i P.O. Box 144 18 GflANITE STHEET i ,m ' . NEWTON. N.H. 03858 HAVERHILL. MASS. 01830 r"iniCl (617)372-8536 ^%1^^ Control Your Life! Now have full computer control of up to 256 lights, ap- pliances and even wall switches without special wiring. The SciTronics REMOTE CONTROLLER permits direct control of the inexpensive BSR remote line-carrier switches sold by Sears, Radio Shack and many others. • Controls all 256 BSR remote switches— not just 16! • Hardware driven — requires minimum software • No ultrasonic link — prevents erractic operation • No BSR command module necessary • Real time, crystal controlled clock available The controller comes complete with full documentation, sample software and is designed to work with most of the popular computers including any S-100 based system, TRS-80-1, Apple II, Heath H8 and others. Real time clocks are available for all of the above computer systems. When used with the controller, true time scheduling is realized. All clocks are crystal controlled and have battery backup for accurate and reliable operation. Interrupts allow Foreground/Background operation of two programs simultaneously. Clock data includes year, month, date, day of week, hour, minute, and second. Applications: • Make your entire home or apartment computer controlled • Save energy by controlling lights & appliances • Control security systems & alarms Remote s\^,itchcs not included S-100 CONTROLLER BOARD $159. S-100 REAL TIME CLOCK BOARD $139. ENCASED CONTROLLER [TRS-80, Apple etc.) $184. ENCASED CONTROLLER & REAL TIME CLOCK (TRS-80, Apple etc.) $269. APPLE CLOCK BOARD ONLY $109. Send check or SciTronicS InC. money order to: 523 S Clewell St., P.O. Box 5344 Bethlehem, PA 18015 (215)868-7220 Please list system with which you plan to use controller. Master Charge and Visa accepted. PA residents add sales tax COD's accepted. Circle 181 on inquiry card. BYTE September 1980 269 Exploring Ballistics with Your Computer Robert W Jenks POB 962 Islamorada FL 33036 Many sports are intricately in- volved with the properties of objects lofted into the air and thereby com- mitted to the inevitable effects of gravity. Both players and fans relish golf's hole-in-one, the long bomb to the wide receiver in football, and the home run in baseball. In the case of target shooting, the path of the pro- jectile is of particular interest. How the bullet gets to the target is the pro- vince of physics, but where it lands resides solely in the skill of the shooter. BALISTIC is a program to calculate just where a bullet will go. Ballistics Ballistics is the study of the behavior of projectiles at various ranges. Of interest to shooters are the velocity, time of flight, drop, and drift at evenly incremented ranges of 50 or 100 yards. Also of interest is the maximum height attained by the bullet above a horizontal line from the bore to a bull's-eye, the trajectory above and below a line of sight at various ranges, and the energy of the bullet. A variety of factors influence the path of a bullet as it leaves the muz- zle; most important are muzzle velocity, gravity, and air resistance. Muzzle velocity is determined by in- ternal ballistics and factors such as bullet weight and bore diameter, bar- rel length, powder weight and burn- ing rates, and maximum pressures. The calculation of these factors is beyond the scope of this article. Muz- zle velocity depends upon the direc- tion of the bore relative to the horizontal, since a velocity is formal- ly a vector quantity. As it leaves the muzzle, though, the speed of the bullet can be most easily measured with an instrument called a chronograph. Bore elevations at reasonable ranges are typically less than a quarter of a degree, and therefore are of negligible influence. The acceleration of gravity is depen- dent on latitude and altitude (and thus on the distance to the center of the Earth), and upon local rock densi- ty and underlying mass. This, too, tends to minor deviations: only 0.5% from the equator to the poles, only 0.15% from sea level to 15,000 feet. The acceleration of gravity can be regarded as a constant 32.1725 feet per second per second in English system units. Air resistance is the most com- plicated factor, and its effect is depen- dent on the density of the air, temperature (and thus the speed of sound), wind velocity, and the prop- erties of the bullet — specifically, speed, sectional density (proportional to the ratio of mass to frontal area), and shape. Whereas gravity pulls the bullet toward the center of the Earth, air resistance acts as a drag opposite to its direction of motion at any in- stant. This effect of air resistance, in- dependent of gravity (under usual conditions), determines the time of flight to any range and the remaining velocity. The effect of gravity com- bined with the influence of air resistance determines bullet drop at any range. Therefore, the calcula- tions of the effects of the air naturally come first. Air Resistance The effect of the atmosphere is to push against the moving bullet. Be- cause a force acting on a mass results in an acceleration or deceleration, depending upon the force's direction, a bullet is decelerated at a rate pro- portional to the ratio of the drag force to the mass. For a standard projectile, this retardation R is related to a cons- tant A times a power m of the veloci- ty at any instant: thus R=AV"'. It has been deduced that the retardation or drag (call it r) for any other projec- tile differing from the standard only in scale of size is directly proportional to a ratio of the standard projectile's deceleration to a factor known as the ballistic coefficient: thus r = R/C. The ballistic coefficient C for a bullet dif- fering in varying degrees of shape from the standard is, in turn, propor- tional to the ratio of the sectional density to a quality called the form factor (commonly known as 0: thus C={w/d^)/i. The form factor is usually disagreeably hard to calculate from 270 September 1980 © BYTE Publications Inc Circle 182 on inquiry card. Circle 183 on inquiry card. EVADA ForCP/M Powerful subset of ANSi-74 Order now! All the elegant simplicity of COBOL is now affordable! r 195 24 ^ WE ACCEPT Z\\\% Computing 1480 17th Av*nu« San Francitco, CA 94122 (415) 664-1534 tn CAaddsaJes tax. CP/Mtrade markol Digital Research. 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Our covers are in use in every state and in more than 50 countries. We know what it takes! THE BEST DUST COVERS AT ANY PRICE m jfP MOST PRICED $795 to $11.95 PLGS POSTAGE AMD HAMDLIMG VISA-MasterCharge So visit your dealer or contact Cover Craft for our latest catalog and list of over 200 dealers. C COVER CRAFT P.O. BOX 555 • AMHERST, NH 03031 • (603) 889-6811 Circle 184 on inquiry card. BYTE September 1980 271 geometric properties alone, and is therefore inferred from the results of ballistic experimentation. But for ogival pointed bullets (ie: a bullet with a point shape defined by a cir- cular arc meeting parallel straight sides at a tangent, or spitzer) i = vTI5?^^^W7n^, n = L2 + 0.25, n equals the ratio of arc radius to bullet diameter, L equals the ratio of bullet- head length to diameter (see reference 1). Most bullets are ogival in shape, but serious changes in the form factor are caused by even small flats on the nose (such as hollow points or dents in soft-nose jacketed bullets), and no further use of this mathematical rela- tion will be made. Since the velocity of a bullet at any time is dependent upon the decelera- tion, which in turn is dependent on the instantaneous velocity, a differen- tial equation is involved. Since a change in velocity is dependent on the integral of acceleration, the use of the calculus is formidably indicated. Whereas given an initial muzzle ve- locity one might attempt to tabulate range and velocity for suitably small increments of time, it is easier to tabulate changes in range and time for suitably small decrements in ve- No typing skills required It's easier and more accurate to enter alphanumeric data with a BIT PAD than a keyboard. 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Peripheral Products (203) 384-1344, W'Summc^/ia/ol^ The BIT PAD alternative to keyboaid dataent p|2 3 A 5 6 7 a ^^SPVffiP lAje c D B F G H* dPpnKi^iH |n|o Pj Q n S J. U vjwf x| ^T^ '% mt^ locity, and avoid the calculus entire- ly. Summations of these increments of time and range give the total time of flight to a given distance. To do this the values of the constants A and m in the equation K = P\S/^ must be determined. Values for the constants A and m were determined by Russian Colonel Mayevski based on data compiled by the German firm of Krupp Armorers in 1881. These figures were converted into English units by Colonel James M Ingalls of the United States Army in the form of a famous tabulation known as the Ingalls Ballistics Tables. The standard projectile used in the Krupp firings was a spitzer-pointed projectile of 2-caliber radius, flat base, and an overall length of 3 caliber. The shape of small-arms bullets today is similar enough to this standard projectile to allow the In- galls tables to closely predict their performance. It was found that the factors A and m varied with velocity, but could be taken as constants within suitable limits of velocity and still give accurate results. Thus eight ranges of velocity from 5000 feet per second (fps) to fps, each with its own constants A and m, cover the range of small-arms bullets. The fac- tors A and M in listing 1 are these constants. Also available in the pro- gram are the constants to reconstruct the British Ballistic Tables of 1909: these seem to more closely agree with hand-loading data such as is in the Sierra Bullets Reloading Manual (for the reloading of cartridges by the shooter). To reconstruct the Ingalls or British tables, a standard projectile is as- sumed, with a Krupp-shaped nose, weighing 1 pound, 1 inch in diameter, and with an assigned standard ballistic coefficient of 1 and a form factor of 1 (since Wd^ = 1/1^ = 1). For a small change in velocity v = U— W (L/ = initial velocity, PV= final veloc- ity over a small change in velocities), and average velocity V=(U-\-W)/2, the time for the projectile to decel- erate from U to Wis f =u/AV"', and the distance over which it travels s = v/AV^""~'^\ The total time to slow from a given muzzle velocity to any velocity W equals the sum of all these increments of time (T=L t) and the total distance S = L s. The computer solves these summa- tions for any bullet, given either its ballistic coefficient or form factor 272 September 1980 © BYTE Publications Inc Circle 185 on inquiry card. Circle 186 on inquiry card. Listing 1: BALISTIC, a North Star BASIC ballistic program. The workings of this pro- gram and the peculiarities of North Star BASIC are described in the text. 10 20 30 40 50 60 70 QO ] 90 100 110 120 130 140 150 160 170 180 190 200 210 220 230 240 250 260 270 280 290 300 310 320 330 340 350 360 370 380 390 400 410 420 430 440 450 460 470 480 490 500 510 520 530 540 550 560 570 580 590 600 610 620 630 640 650 660 670 680 690 700 710 720 730 740 750 760 770 780 790 800 810 820 830 840 850 860 870 880 890 900 910 920 930 ri REM ** -BALISTIC &Y R U JENKS 1979 MOD 9/10/7 GOSUB 1540\REM (OUTPUT TO TERMINAL) LINE 79 DIM C'Ji(50)f T(10f2> Cl = l\ A4^:^^l\ l'=5\ R3^500 I CHR$(27> fCHR$(42) REM ** INPUT PARAMETERS ** INPUT "CALCULATE BALLISTIC CGErFICIENT (YES/NO)T ".1$ IF I$='YES" THEN F^^^^l ELSE F-O INPUT -INGALLS OR BRITISH 1909 TABLES? " r 1$ IF I$(lf 4)='INGA" THEN Fl=l ELSE Fl^O T3=59H*F1 P1=29,53+»47*F1 INPUTl "WIND SPEED :'tU1\ ! " Miles Per Hour" INF'UTl "CROSS WIND ANGLE!" fAl\ ! " Dedrees From &ro<3di:-ide U2 = Ul*C0S(2*3»1415927*Al/36 0>:KQQ/60 IF I$="U" THEN 460 INPUT "cartridge: "rC$ INPUTl 'WEIGHT:" tU\ ' " Grsins' U=U/7000 INPUTl 'CALIBER: "tD\ J " Inch" IF F THEN 290 INPUT 'BALLISTIC COEFFICIENT :' fC IF COO THEN 260 INPUT 'FORM factor: '. I IF C=0 THEN C=(U/D"2)/I IF 1=0 THEN I=(U/D"2)/C C1=C INPUT "NON STANDARD CONDITIONS (YES/NO) ?'?!$ IF I$<>'YES" THEN 460 REM ** NON STANDARD ATMOSPHERIC CONDITIONS ** INPUTl 'temperature: " fT3\ I " Decrees Fahrenheit" INPUTl "pressure: "rPl\ ! ' Inches Mercur-j" INPUTl "ALTITUDE: ' tA2\ ! " Feet" T4=59-(3.566E-3)*A2+1*F1 P2=29»53-(8.581E-4)*A2+(8.602E~9)*A2'^2+»47*F1 A3 = 1 + (3.073E-5)*A2+(6.371E-10)*A2''2 A4=A3*(2-Pl/P2)*(T3+459*4)/(T4+459*4) C=C1*A4 IF F THEN 430 !\! "MODIFIED C : " f ;i5F3 f C\ ! GOTO 440 T3=59+1*F1\ P1=29.53+.47*F1\ A2=0 I=(U/D"2)/C REM ~ END OF ROUTINE — IF NOT F THEN INPUT "TO 500 OR 1000 YARDS? ' f R3 R3=R3/500 INPUTl "MUZZLE VELOCITY :'. Vl\ ! ^^2=V1 + V\R2 = IF NOT F THEN 560 INPUTl 'RANGE :"fRl\ ! ' Yards" R1=R1*3 INPUTl "FINAL velocity: " fV4\ ! ' I=l\ C=l\ GOTO 700 REM ** PRINT DATA ** • "rC$r TAB<50)rINT=R2 THEN 870 GOTO 710 REM ** RESULTS OF BC/FF CALCULATION ** S=S1 + (S-S1 )*(V2+V-V4)/(2*V) C=(R1/S)/A4 I = (U/D''2)/C 'BALLISTIC coefficient: ■r%*5F3fC 'FORM factor:" f If %* C1=C\F=0\ GOTO 1090 REM ** PRINT A ROW OF BALLISTIC DATA ** V3=(V2 + V)-2*V*(R2--S1)/(S-S1) E = V3''2*U/32. 1725/2 T2=T1+(T-T1)*(R2-S1)/(S-S1) T(R2/<150*R3)f0)=R2/3 Dl=( 110.3+82 ♦7*V3/V1)*T2"2 T(R2/(150*R3)t1)=D1 U3=12*U2*(T2-R2/V1) Listing 1 continued on page 274 Software Development Tools PASCAL/M™ The CP/M"'"M compatible language for 8" 8080/Z80 CPU's, NorthStar 2D, Cromemco CDOS & TRS-80 Mod II. • Randonn access files • Runtime debug support • Over 45 extensions to Standard Pascal • 9511 A math chip version available $175. Manual alone - $10. ACT'^' NEW! CP/M compatible macro assembler forZ80, 8080/85, 6502, & 6800. FINALLY, one assembler that sup- ports all major 8 bit micros and runs under CP/M. ACT is available now in 8" soft sectored & NorthStar CP/M formats. COMING SOON: ACT FOR 8086/88 & 6809. $125. Manual alone • $15. PEARL™ The application software generator. Pearl asks questions that a pro- grammer would have to answer to code the system. You answer the questions and Pearl uses built-in logic to construct both subroutines and mainline programs. The system then complies and executes your program code. • Level 1: For Personal Computing -$130. • Level 2: The Business Assistant - $350. • Level 3: Advanced Software Development -$650. CBASIC2TW required. Manuals alone • $25. each CBASIC2 Latest release 2.06, CP/M2-MP/MTM, or TRS-80 Mod I. Specify CP/M ver- sion & format (8" soft-sectored, NorthStar, Micropolis, TRS-80, etc.) $95. Manual alone - $15. DIGITAL MARKETING 2670 Cherry Lane Walnut Creek, CA 94596 (415) 938-2880 Pascal/M & ACT are trademarks of Sorcim CP/M & MP/M are trademarks of Digital Research Pearl is a trademark of Computer Pathways CBASIC is a trademark of Compiler Systems TRS-80 is a trademark of Radio Shack Outside USA add $10. for postage & handling September 1980 © BYTE Publications Inc 273 Circle 187 on inquiry card. JBuy By Mail and Save! 5 INTERTEC SuperBrain® 32K . $2495 64K RAM, List $3345 $2695 64K Quad, List $3995 $3395 NORTH STAR Horizon I® 16K D.D. Kit $1259 32K D.D. 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VISA and Master Charge add 3%, CO.D. orders require 25% deposit, Prices subject to change without notice. Computers Wholesale P.O. Box 144 Camillus, NY 13031 S (315)472-2582 Listing 1 continued: 940 950 960 970 980 990 : 1000 1010 1020 1030 1040 1050 1060 1070 1080 1090 1100 1110 1120 1130 1140 1150 1160 1170 1180 1190 1200 1210 1220 1230 1240 1250 1260 1270 1280 1290 1300 1310 1320 1330 1340 1350 1360 1370 1380 1390 1400 1410 1420 1430 1440 1450 1460 1470 1480 1490 1500 1510 1520 1530 1540 1550 1560 THEN 140 THEN 320 THEN GOSUB THEN (30SUB 1540 1550 THEN 1100\ IF I%= THEN 1100 ! ;i5I»INT(R2/3+,5) r XIOI f INT( V3+ . 5 ) » ;i8I» INT (E+ . 5) r ! ;ilOFlr48*T2"2f%8Flfrilf ;i7FlTU3r" •T;i6F3»T2 R2=R2+150*R3 IF NOT(NOT F AND R2::-1500*R3) THEN 710 REM ** TRAJECTORY TABLE ** INPUTl "SIGHT ON ATt " fR4\ 1 " Yards 'f INPUTl "SIGHT height: "tHV ! " Inches" FOR X=0 TO 10 T ( X r 2 ) =T ( R4/ ( 50*R3 ) r 1 ) *T < X » ) /R4 ~T ( X ^ 1 ) -H* < R4-T ( X » ) ) /R4 NEXT ! "RANGE Yards "^\ FOR X=0 TO 8\ ) %7IfTM/3 (see reference 1). To determine an actual trajectory, the curve of the bullet path versus range is tilted up just enough so that the curve crosses a horizontal line (from the muzzle) at the given range where the gun is to shoot on target. This is effectively accomplished for small angles of elevation by subtract- ing from the drop, at the range, an amount proportional to the product of the bullet drop at the targeted 276 September 1980 © BYTE Publications Inc Circle 189 on inquiry card. Circle 190 on inquiry card. range times the ratio of any range to the targeted range (o = d — Dr/R, where o= modified ordinate relative to the horizontal, d=drop at any range, D = drop at targeted range, r=any range, i? = targeted range). A table of discrepancies between the path of the bullet and the horizontal is modified for the difference between the angle of the line of sight and the horizontal (crossing at the targeted range). Thus = o-h(R-r)/R, where O = the ordinate from the line of sight, and h= the separation of sight and bore; h usually varies from 0.75 to 2 inches. For any given target range, the maximum height reached by the bul- let above the horizontal while travel- ing to that range is H = 48P inches. Maximum height and midrange tra- jectory are nearly identical over the limits of practical shooting distances. Crosswind Though the effect of air resistance on bullet drop is somewhat odd, the effect of a crosswind is downright confusing. One would think that a bullet in a crosswind might do one of three things: it might quickly begin drifting with the wind if it were light relative to its lengthwise sectioned area, or it might resist the wind tenaciously if it were massive relative to this area, or, most likely, it should do a little of both; drifting to the ex- tent that it is light and resisting to the extent that it is massive. In any case its crosspath acceleration should ap- pear to be smooth as its sideways speed approaches that of the wind. In truth, though, a bullet will drift an amount equal to the product of the component of the wind perpendicular to the axis of the bullet multiplied by the difference between the time the bullet takes to reach any range and the time it would take to reach that range were it fired in a vacuum. This time of travel in a vacuum equals the range divided by the muzzle velocity. It is hard to believe that both a slow- moving bullet and a fast-moving bullet (ie: bullets moving slower or faster than the speed of sound) drift less for the same ranges than bullets moving more nearly at the speed of sound, even though the fast-moving bullet gets to the target sooner and the slow-moving bullet gets there later. 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YES INGALLS OR BRITISH 1909 TABLES"-' BRITISH WIND SPEED:8 Miles Per Hour CROSS WIND ANGLE:32 Decrees From Broadside cartridge: .22/250 UEIGHT:55 Grains caliber:. 224 Inch NON STANDARD CONDITIONS (YES/NO) ?YES TEMPERATURE :68 Decrees Fahrenheit PRESSURE:29.00 Inches Mercury ALTITUDE:2150 Feet MUZZLF UEL0CITY:3800 Feet Per Second RANGE:400 Yards FINAL VEL0CITY:2460 Feet Per Second BALLISTIC coefficient: .285 FORM factor: .550 ? TO 500 OR 1000 YARDS? 500 MUZZLE VEL0CITY:3800 Feet Per Second .22/250 55 Grains .224 Caliber BALLISTIC coefficient: .285 FORM FACTOR: ,550 Based on BRITISH 1909 Ballistic Tables WIND 8.0 MPH FROM 32.0 Decrees CROSSUIND 10.0 FPS TEMPERATURE 59.0 Decrees F PRESSURE 29.53 Inches H3 ALTITUDE Feet RANGE UELOCITY ENERGY MAX HEIGHT DROP DRIFT TIME YARDS FT/SEC FT--LBS IN. IN. IN. SEC. 3800 1763 .0 .0 .0 .000 50 3601 1583 .1 .3 .1 .041 100 3409 1419 .3 1.3 .5 .083 150 3224 1270 .8 3.0 1,2 .129 200 3046 1133 1.5 5.5 2.2 .176 250 2875 1009 2.5 8.9 3.6 .227 300 2710 897 3.8 13.4 5.3 .281 350 2552 795 5.5 18.9 7.4 .338 400 2399 703 7.6 25.8 9.9 .399 450 2250 618 10.3 34.2 12.9 .463 500 2107 542 13.6 44.2 16.4 .532 SIGHT ON at:2oo Yards SIGHT HEIGHT:1.5 Inches RANGE Yards 50 100 150 2 00 250 300 350 400 TRAJECTORY In. -1.5 -.1 7 .8 .0 -1.7 -4.4 -8.2 -13.3 ?A TEMPERATURE :68 Decrees Fahrenheit PRESSURE 29.00 Inches M e r c u r a ALTITUDE 2150 F eet MODIFIED C .300 TO 500 OR 1000 YARDS? 500 MUZZLE velocity: 3800 Feet Per Second .22/250 55 Grains .224 Caliber BALLISTIC coefficient: .300 FORM FACTOR: .522 Based on BRITISH 1909 Ballistic Tables WIND 8.0 MPH FROM 32.0 Decrees CROSSUIND 10.0 FPS TEMPERATURE 68.0 Decrees F PRESSURE 29.00 Inches H3 ALTITUDE 2150 Feet RANGE VELOCITY ENERGY MAX HEIGHT DROP DRIFT TIME YARDS FT/SEC FT-LBS IN. IN. IN. SEC. 3800 1763 .0 ,0 .0 ,000 50 3611 1592 .1 .3 .1 .040 100 3428 1435 .3 1.3 .5 .083 150 3252 1291 ,8 3.0 1.2 .128 200 3082 1160 1.5 5.5 2.1 .175 250 2918 1039 2.4 8.8 3.4 .225 300 2760 930 3.7 13.2 5.0 .278 350 2607 830 5.4 18.7 6.9 .334 400 2460 739 7.4 25.4 9.3 .393 450 2317 656 10.0 33.5 12.1 .456 500 2178 579 13.1 43.2 15.3 .523 SIGHT ON at:2oo Yards SIGHT HEIGHT:1.5 Inches RANGE Yards 50 100 150 200 250 300 350 400 TRAJECTORY In. -1.5 -.1 7 .8 .0 -1.6 -4.3 -8.0 -12.9 ?T 278 September 1980 © BYTE Publications Inc Circle 192 on inquiry card. transiting the speed of sound (slowing down in its motion toward the target), and then settles back to drift- ing at small incremental velocities from there on. The logic behind the observations is that the amount of deceleration af- fecting a bullet traveling close to the speed of sound is large (as a measure) due to turbulence. At both higher and lower speeds, the combined effects of base drag, skin friction, and nose drag are changing less over a given range, and so the bullet travels this distance nearer to the time it would take were it able to maintain its initial velocity. Were the bullet able to ar- rive at a given range in the time it would take if it could maintain its muzzle velocity, this would imply an absence of air resistance, an absence of wind, and thus no drift. This sup- ports the dependence on the time dif- ference. Also affecting the horizontal path of a bullet is a gyroscopic effect caus- ing the bullet to point away from its initial line of flight. As the bullet falls, additional air resistance appears on the bottom of the bullet. This leads to asymmetrical torques around the center of mass which cause the bullet to attempt to tilt around a horizontal lateral axis, but because the bullet is spinning, the gyroscopic effect resists the turning moment and redirects it by 90°, thus causing the bullet to yaw and veer away from the line of the bore. The effect is minor and only amounts to 6.7 inches at 1000 yards for a 150-grain, full-jacket 30-06 bullet. The Program BALISTIC, listing 1, is written in North Star BASIC for use on a North Star Horizon computer and may need modification for use with other B ASICs. An exclamation point (I) is North Star BASIC shorthand for PRINT. The backslash ( \ ) is the multiple-statement-per-line separa- tor; commas separate print items. Line 60 of the program sends the clear-screen command for a Soroc IQ-120 terminal, an Escape-asterisk (ESC-*) sequence. Lines 1540 and 1550 modify the North Star BASIC disk operating system output routine so as to reconfigure output to either the standard serial port (terminal) or secondary serial port (printer), and thus doing away with the need for device designation parameters in all ■n?s«),PEr, APPLE, SORCERER Communications Interface Systems I 1. iTii!" DSend & Receive Morse Code / Radioteletype D Teaches Morse Code! / Copies wire services! n Complete Hardware & Software Package D Extensive User Manuals D From $129 Write or call for complete catalog A1>]CR0TRONICS. inc. ® 1125 N. 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We pay all shipping and Insurance charges except items marked with asterisk. VISA, MasterCharge add 5% N.Y.S. Residents add appropriate sales tax. ♦(DENOTES ITEMS SHIPPED F.O.B. NYC) PHONE (212) 986-7690 Micro Computer Discount Co 60 E. 42nd St.. Suite 411. New York, N.Y. 10017 September 1980 © BYTE Publications Inc 279 PRINT statements. Lines 1540 and 1550 should be replaced with ap- propriate routines or just RETURNs on all computers where such execu- tion might cause havoc. BALISTIC runs in 5300 bytes, but can be shortened by deleting spaces and remarks, and by merging statements onto fewer lines. BALISTIC may also be shortened by excising the routine for the constants of one or the other ballistic tables. Operation The program is self -prompting for the most part, as shown in listing 2. It operates in two major modes: simulating bullet performance based on parametric input or calculating normalized ballistic parameters based on experimental data (after which it returns to the simulation mode). Units are English, and terminology is characteristic of the shooting sports (7000 grains per pound). Pertinent in- formation is repetitively printed so that it is not lost in the shuffle. A suitably placed GOTO statement bypassing these lines saves paper when you are compiling records such as handloading information. When the computer prompts for the caliber, the bore diameter plus the depth of one groove is expected: the diameter of the bullet is a suitable alternate. If the ballistic coefficient, C, is not known, but the form factor, z, is known, entering for C allows the computer to prompt for z. When the computer prompts for the max- imum range to which to calculate, any range may be entered, not just 500 or 1000 yards. But when the pro- gram asks for the "SIGHT ON RANGE," a range listed in the table must be used (other than 0). The question mark following the trajec- tory table prompts for an "A", "P", "T", "VJ", or a carriage return — for new atmospheric data, printer or ter- minal output, new wind data, or reiterate. Conclusions I hope all the major factors that af- fect bullet performance have been in- cluded, so that accurate results are possible. The greatest, though un- quantized, limitation is that the bal- listic coefficient changes with velocity for projectiles differing from 1 in form factor. The farther from stan- 9 Programming? n Best Seller That Speaks for Itself — r ■>■> —I' / THE ART OF COMPUTER PROGRAMMING By Donald E. Knuth Praised by many critics as the best books in their field. The Art of Com- puter Programming, Volumes I, ii and 111, are part of a projected seven volume omnibus survey of computer science now being completed by Donald E. Knuth. A hypothetical assembly language called MIX has been developed by the author to illustrate programming examples throughout the series. MIX is easily convertible to other assembly languages. Prot. Knuth writes with style and wit (among many memorable quotes is one from McCall's Cookbook)! This classic work belongs on the reference shelf of everyone seriously interested in computer science. Pledse Check' DVOLUME I, FUNDAMENTAL ALGORITHMS 634pp. Hardcover #007-090 $23.50 DVOLUME II, SEMINUMERICAL ALGORITHMS 624pp. Hardcover #008-090 ^ $23.50 DVOLUME III, SEARCHING AND SORTING 722pp. Hardcover #009-090 $23.50 BITS, Inc. Books to erase the impossible P.O. Box 482 Peterborough, N.H. 03458 Postage and handling $1.75 per book Please check: D VISn D MosterChorge D Check or monev order Call 24 hours a day: 800-258-5477 N.H. Residents 924-3355 dard this deviation, the less accurate- ly will the calculated results match the real bullet performance, since the standard projectile will be less of a model for the actual bullet. Even so, the calculations tend to match actual performance within 1% for velocity and 2% for bullet path out to 500 yards or more, and compare nicely with publislied cartridge manufac- turers' information and reloading guide data. Do not expect especially accurate results for blunt-nosed bullets or slow-moving boattails, though. But the accuracy is probably consistent with random variations in the actual physical conditions such as spatial variations in wind speed and direction, air temperature and humidity, bullet imperfections and variations in weights, etc. Reduction of published data might indicate a mathematical relationship between bullet geometry and the way the ballistic coefficient changes with ve- locity, and thus the equations in the program might be modified for more universal simulations. See the references for other sources and additional information. Hatchers Notebook is extremely in- teresting reading on a variety of shooting subjects. Other reloading guides are also valuable. So go ahead, load BALISTIC, and take your computer to the range. ■ References 1 . Hatcher, Maj Gen Ret Julian S, Hatcher's Notebook, Third Edition, The Telegraph Press, Harrisburg PA, 1966, Library of Congress number 62-12654. 2. Sierra Bullets Reloading Manual, First Edi- tion, 1971, Sierra Bullets, 10532 S Painter Ave, Santa Fe Springs CA 90670. 3. Walters, Kenneth L, "Crosswind Deflec- tions: a Cast Bullet Anomaly." Gun Digest, Thirty-third edition, 1979, DBI Books Inc Northfield IL. Give to the college of Your choice. f B^ Council for Financial Aid to Education. Inc nfc 680FifthAvenue. NewYork. NY l00i9 ^i I A Public Service of This Magazine & The Advertising Council. 280 September 1980 © BYTE Publications Inc Circle 193 on inquiry card. Circle 194 on inquiry card. SPECTACULAR Introductory Offers BASF "FLEXYDISK" Superior quality data storage medium, certified and guaranteed 100% error free. 5W' Diskettes * 10 @ $24.0o\\i 8" Disks* 10 @ $24.00 Vinyl storage pages 8" or 5V*" 10 @ $ 5.00 Write for quantity discounts •Single Sided / Single Density SFD CASSETTES "Super Ferro Dynamic" Using tfie finest Agfa PE 611 tape in a professional quality fiousing. 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CARD 529 SOFYWARE PASCAL LANGUAGE SYSTEM S445 FORTRAN LANGUAGE PACKAGE 175 THE CONTROLLER GEN. BUS. SYSTEM ... 529 THE CASHIER RETAIL MGT. 4 INV 209 APPLEPOST MAILING LIST SYSTEM 45 APPLEWRITER WORD PROCESSOR 69 VISI-CALC 125 SARGON II on Disk 35 SUPER INVADER On DISK 25 WE WILL GLADLY PERFORM WARRANTY REPAIR ON ALL APPLE COMPUTER PRODUCTS. MONIYORS LEEDEX V!DEO 100 12" BLACK & WHITE MONITOR •VIDEO BANDWIDTH 1 2 MHzlSdb •COMPOSITE VIDEO INPUT $10QSOROCIQ120$739 lm3^S0R0ClQ140$1295 SANYO 9" B/W Monitor $169 • SANYO 15" B/W Monitor $259 • ZENITH 13" Color Monitor $429 PAPER TIGER ITS 440 w/qraphi.cs. . . . $i 050 TRENDCOM T-200 559 CENTRONICS 737 850 CENTRONICS 700-9 1149 ANADEX DP-8000 OR AP 850 MPiaa-T 725 SORCERER 11 16K NEC SPINWRITER 2695 AXIOM EX-801 495 AXIOM EX-820 750 COMPRINT 91 2S 599 COMPRINT 91 2P 559 TRENDCOM T-100 349 •computer internally expandable THE AMAZING The SORCERER is o 280 CPU to 'laK 4K ROM resident monitor 10 conncclor lor S-100 expansion. Parallel and serial interface Dual cassette 10 Graphic resolution of 240 x 512. 30 lines of 64 characters. 8 x 8 dot matrix Full ASCII set lupper and lower case), plus standard graptiic symbols User may define up to 128 cfiaraclors Keyboard is 63key data processing type. Plus a 16 keynumeficinpulpad S-10t} EXPANSION UNIT WORDPROCESSOnPAC ., DEVELOPMENT PAC S555 31K 1,145.00 48K 1.195.00 A ATARI $799 ,Q »r»R( 400COMPUIER $449 »rA8H20PRINTEi! 489 ATARlglOOlSKORtVE 579 ATARI 410 PROGRAM RECOROER 69 ATARIUX RAH MODULE 149 ATARI !K RAtil tilODULE 99 ATARI BASICROH 45 ASSEMBLER/EDITOR 45 •High resolution COLOR Graphics •1 OK Basic in ROM •8K user RAM expandable to 4eK •57 key lull strokekeyboard BASKETBALL 30 VIDEOEASEL 30 SUPER BREAkOUI 30 llilUSIC COHPOSEd 45 COHPUTERCHESS JO 30IICTACTOE 30 STARRAIOERS * 45 PERSONALFINANCE 45 •Built-in RFTV modulator •High speed serial 10 port •Includes ATARI 4 1 program • TO ORDER • Phone orders invited, using credit cards. Or send cashiers check or money order that draws on a U.S. bank. Please add 3% ($5.00 Minimurn) for handling, shipping (air service) and insurance, or equipment will be shipped freight collect. California residents add 6% sales tax. All equipment is in factory cartons with the manufacturers warranty. Eauipment is subject to price change and availability without notice. r .^.^ ^ fmasier charge] ^^ ^^^^*^^^^* VISA COMPUTER SPECIAUIES 6363 EL CAJON BLVD., SUITE 205, SAN DIEGO, CA. 92115 • (7141 579-0330 Circle 196 on inquiry card. BYTE September 1980 281 An Interrupt-Driven Real-Time Clock for the TMS 9900 Thomas G Morris Jr 861 St Mary Ave San Leandro CA 94577 One of the first things many com- puter enthusiasts feel the need for is a real-time clock for their personal computers. With many different methods available for the computer to main- tain the time of day, I decided that any real-time clock should have a reasonably low software overhead and simple hardware approach. Processor Overview One of the 16-bit microprocessors now readily available to computer users is the Texas Instruments TMS 9900. The TMS 9900 is a 16-bit processor using a memory-to-memory architec- ture that allows multiple register files (known as workspaces) to reside in memory. A workspace is defined as sixteen contiguous words of memory, addressable as registers RO thru R15. This method increases programming flexibility and produces a faster interrupt-response time than other processors have; a context switch may be performed without the use of a stack. Registers The processor contains three hard- ware registers. They are: • program counter (PC) • status register (ST) • workspace pointer (WP) The program counter contains the address of the instruction following the currently executing instruction. 1. Register (MOV R0,R1) 2. Register Indirect (MOV *R0,R1) 3. Register Indirect (MOV *R0 + ,R1) with Auto-lncrennent 4. Direct (Synnbolic) (MOV R0,@ Label) 5. Indexed (MOV R0,@Label(R1)) 6. Innnnediate (LI RO,>FFFF) 7. Relative (JMP$ + 3) Table 1: The 7 main addressing modes of the Texas Instruments TMS 9900 16-bit processor, given with assembler- mnemonic representation. Additional address- ing modes can be simulated by subroutines called through extended-operation (XOP) instructions. The status register contains the cur- rent state of the processor (ie: flags and interrupts). The workspace pointer register points to the first word of the current workspace. Addressing The TMS 9900 has both word and byte addressing capability. The byte- addressing mode is internal to the processor and references the leftmost byte of a workspace register. There are seven main addressing modes. These are given along with the assembler mnemonics in table 1. Interrupts The TMS 9900 utilizes sixteen vec- tored interrupts. The interrupt vec- tors are contained in hexadecimal memory locations 00 thru 3C and consist of the interrupt workspace pointer and a pointer to the interrupt code. When an interrupt has been About the Author Thomas G Morris Jr works for General Elec- tric as a minicomputer systems software analyst. His personal computer is a Technico Super Starter system with 32 K bytes of pro- grammable memory, 2 K bytes of program- mable read-only memory, and 2 K bytes of read-only memory containing a monitor and disk handler. Peripherals include an 8-itich floppy disk, paper tape reader, a Southwest Technical Products AC-30 cassette unit, and a Texas Instruments 733KSR terminal. 282 September 1980 © BYTE Publications Inc Circle 197 on inquiry card. Circle 198 on Inquiry card. SORCERER SOFTWARE SYSTEM 2 by Richard Swannell, loads mio ihe top of available RAM and becomes an mlegral pafi ot Ihe BASIC language. All commands are single keystroke. SYSTEM 2 is written m Z80 and provides the following features: 1 . SCREEN EDITOR. Use the editor to insert, replace, delete or rubout characters m your BASIC program. Watch the line change on Ihe screen! Gone are the days ol typing m a whole line to change one character' 2. FUNCTION KEYS. SYSTEM 2 allows 12 keys to be programmed lo represent one or more characters or up to several lines of text eachi After a keyis programmed, by simply hitting key, all the text is sent to the processor iu:t as If you typed it in on the keyboard! Function keys may be used in all modes of operation, including the editor. This feature is handy lor lengthy and ot often used commands and may mclude multiple statements. 3. RENUMBERING ROUTINE. With a single keystroke your program is renumbered. Starting line number and increment may be cfjanged. 4 BASIC BUFFER PROTECTOR. SYSTEM 2 sends a ICRI when the BASIC BUFFER is full This prevents BASIC from crashing 5 PRINTER DRIVER. Simply hit CTRL P to direct output to Centronics printer. 6. RIVfVAL ROUTINE . II NEW or CLOAD are typed, or RESET is hit by mistake, your program may be recovered. This IS a satety device. OTHER FEATURES RUNSTOP stops execution until any oiner key is hit - CLEAR clears screen then sends a (CR). Hit CLEAR to start on 'new page' - CTRL characters such as ESC, LF and CLEAR don't return 'SN ERROR. - RUB doesn't require the SHIFT key to be depressed. This quickens editing. - Includes a Real Time Random Number Generalot. - Returns automatically to BASIC alter TAPE CRC ERROR while CLOAOing. - Suppresses premature CRLF Normally, d RUB is used extensively while typing in a BASIC line, the cursor will drop down to the next line before reaching the end of the current line. SYSTEM 2 prevents this. - SYSTEM 2 requires 2K of memory and is available in 8, 16. 32 8 48K versions. $35.50 RS232 PRINTER DRIVER. Requires 250 bytes of memory and is relocatable. Suitable for MONITOR. STANDARD BASIC. WORD PROCESSOR PAC & DEVELOPMENT PAC. Stores each character m a buffer then sends the whole line 3t once, which solves timing problems $t0.00 COMBINED SYSTEM 2 b RS232 PRINTER DRIVER. SYSTEM 2 with the RS232 prmter driver instead ot Centronics printer driver $40.00 LUNA LANDER. Written in Z80 and Basic and requiring 16K. LUNA LANOER uses graphics to the full. Land you craft on Ihe moon in real time. Bui be careful to land softly, otherwise you will see your LANDER crumple before your very eyes' $15.00 SYSTEM SOFTWARE 1 Kent Street, Bicton, 6157 Australia Program comes on cassette and includes full documentation. Specify size of RAM. Prices in Australian Dollars. Add $2 tor overseas airmail. SORCERER is a trade mark of EXIDY INC. h G H P S □ [3 □ \!] n □ hGQPQG SB0\^nnGS MRURO PRORC MP-250 PLOTTER - S695 with L2D Plot package - S795 with L2D h L3P packages - S950 MRURO PLOTTER - Uses 11' by 8-1/2" oy any length papev. RBSoIulJon Is 200 steps per inch. 0.005' tracking error. Mauro X-Y vector software wfth pen control is ovaloble for 8080/Z80, 6502, &t 6800 m J era-processor s . Reauires 5 bits of a para{;ni output port. fiPPLL" , TRS-8a , and RS232 Interfaces at-e avnJabIn as I/O Options. LEfiPRC SOi-'TWflRE - Supports compJete 211 h. perspective p.'ot- 'nq, Including flSCl I and cuvv{; rjennrntiun. Pr/allnhie as I ink ing warp. p>-oduct5 ibrcM-iGS (LttO^ MICROSOFT cairpatJblR f "0RTRPN-8C , COfiOL- -80 , COf.'P ! ISR B9.S I C , IoM-37.;C disks sort and N''unCR0--80 in CP/M compatibln files :jn rt" or 5-1/4' ;;eRTriSTnR i'crnntt,-id disks. L2il ~- X-'v' pfut pazUiiQc. Ucntnir includinq Ci^LCCM;^ c::mpntib!e cell WHERL' . " GVfjr 20 crAr I cs , £;uch ns PLOT ar.d L3P - Perspor.t i vR pi tit vc:'U'.:q entviRs. CapcbJn of ZOOM J No [:nri much morR. (Srg 5«if pcu-1' : . Cont nins uvnr 7Q l-'LV-BYS. nNlMmiON •Jit nbovn ) . 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BYTE September 1980 283 60Hz m 12 Rat!) ^9(2) ICI 7490 ^6 Rod) Qb ^0(2) 12 10 Hz 14 Qa Rod) R0(2) B Rsd) '^2 R9t2) 7490 ^^^^ -rIO A Qc rh 8 I Hz ^ ^ + 5V V ENABLE IC3 17404 _^.— , FROM 60Hz "^'^^— ' GENERATOR -OeOHz OUT -Q> I Hz OUT -0> 10 Hz OUT Kh^ IC3 7404 FROM BUFFERS ON IC3 (60,10, OR I Hz) Figure 1: Schematic diagram of the circuit for the real-time clock, with enable, reset, and disable states shown. ICI (a 7490) is wired in a divide-by-6 configuration. FROM _^,^^--i COMMUNICATION ""^— ' REGISTER UNIT PORT Q LATCHED -t3> OUTPUT TO INT/I detected, all lower-priority interrupts are inhibited until the current inter- rupt has been dismissed. The only ex- ception to this is the reset function (which has a priority level of 0). When an interrupt has been de- tected, a context switch is performed by fetching the new workspace pointer and program counter values from the appropriate interrupt vector locations. During this same time period, the old workspace pointer, program counter and status registers are saved in the new workspace regis- ters R13, R14, and R15 respectively. When the interrupt has been dis- missed by the interrupt subroutine, the processor is returned to its preinterrupt state by issuing a return (RTWP) instruction. Input/Output The TMS 9900 employs a direct input/output (I/O) interface method which is designated the communica- tion register unit (CRU). The com- munication register unit provides for a maximum of 4096 bits of I/O capa- bility. From 1 to 16 bits may be set or reset at a time; additionally, single bits may be tested for their value. Clock Hardware The heart of the clock assembly is a crystal-controlled, 60 Hz time-base generator sold by many electronic firms. The time-base generator pro- duces an accurate square wave with a 50% duty cycle, which is fed through IC3, a 7404 inverter (see figure 1). This buffered signal is then directed to ICl (7490), which is set up as a divide-by-6 counter. The resulting 10 Hz signal is then divided by IC2, pro- ducing the final 1 Hz frequency. The 10 Hz and 1 Hz frequencies are buffered by IC3 and made available for use as the minimum interrupt rate. One of the three rates is then directed to the clock input of IC4, which produces the necessary latched output. IC4 (7474 dual-D flip-flop) is needed to guarantee that an interrupt will not be missed, regardless of the level chosen. The exception: if a higher-priority interrupt monopolizes Number Type + 5 V GND IC1 7490 5 10 IC2 7490 5 10 IC3 7404 14 7 IC4 7474 14 7 ( STCLK j ( RDCLK j ZERO INTERVAL TIMER PLACE INTERVAL TIMER INTO RO ( RETURN j ( RETURN j Figure 2: Flowcharts of routines to operate interval timer. the processor for longer than the basic interrupt rate, the low-priority interrupt may suffer. Hardware Interface The clock interface to the computer consists of a simple 2-wire hookup. One wire from the communication register unit port is connected to pin 1 of IC4, clear (CLR), via two sections of the 7404 inverter IC3. This connec- tion provides both the reset and the 284 September 1980 © BYTE Publications Inc Circle 200 on inquiry card. Circle 201 on inquiry card. FOR SERIOUS USERS OF 8080, 8085, OR Z80 COMPUTERS PRINTER WIZARD — Now add powerful capabilities to your printer. Free your computer for use while simultaneously printing backlogged output on a first-in- first-out basis. Transparent operation without noticable slowing of the computer. Allows continuous computer and printer operation on programs having sporadic output. Will backlog up to 100 pages when used with a disk system. Adds optional automatic paging with numbers, adjustable margins on 4 sides, indented overflow lines. Occupies less than IYj K. Documentation only EX80M103 EX80M103D $45.00 $ 7.50 DISASSEMBLER — Disassemble machine code into stan- dard source language. Modify or relocate existing programs such as DOS or BASIC using your existing assembler (not included). Disassembles any 8080, 8085, or Z80 code, in- cluding embedded data blocks and "trick" codes. Generates symbol and label tables. Documentation only EX80M217 EX80M217D $75.00 $12.50 ALL EXCOM products are fully supported and warranted indefinitely against original defects. Available on single or double density NORTHSTAR bV*" diskettes, 300 or 1 200 baud cassettes (specify). Washington residents add 5.3% tax. ExcoM P.O. Box 1802 Bellevue, Washington 98009 U.S.A. Telephone (206) 641-6577 DECLSMl Components Dependable service at discount prices Domestic and Export 1 !T q ll ■ -Xmrn mini Computer Suppliers, inc. 25 Chatham Rd., Summit, N.J. 07901 Since 1973 (201) 277-6150 Telex 13-6476 ©Mini Computer Suppliers. Inc. 1979 PROFESSIONAL 1. Full interactive user control, in tax-form language only, line by line. 2. Screen display of full 1040 and all schedules, prior to printout. 3. Change of a single amount item automatically changes and re-computes entire return. 4. All printout formats IRS and state approved. 5. Stores Preparer's Identification for automatic print- ing at bottom of page 2. 6. Built-in Validation Check tests entire system, hard- ware and software. 7. Special Printer Adjustment routines. Line Length, etc. HALF A MILLION TAX RETURNS CANT BE WRONG! (OR THEY HAD BETTER NOT BE) INCOME TAX SYSTEM FOR TRS-80* MODEL I OR II Our system, which prepared 500,000 1979 returns, features the following: 9 8. Selection of closed or open output formats- standard Form 1040 or open name-box types. ■for Software control of text position on page. Makes forms-alignment simple. Permits use with non- adjustable printers. 10. Fills in pre-printed Forms or you can use overlays. Your choice. 11. Automatically computes: Tax - SDI Overpayment - Wages Total from W-2's - Earned Income Credit - Income Averaging - Maximum/Minimum Tax - Least Tax Method - All Percentage of Income Limitations - All Fixed Limitations - many, many more. 12. Full support through the tax season — no charge. 13. Inexpensive yearly updates in accordance with tax- law changes. 14. Modular construction— lets you order only the type and size system you need. PRICING STARTS AT $189-95 (1040 & SCHEDULE A) 25-Page Descriptive Manual $7.50 (Refunded on Order) Minimum System Required: Model 1, 32K, 1 Disk Drive iRseo is a trademark oi Tandy corp CONTRACT SERVICES ASSOCIATES 706 SOUTH EUCLID • ANAHEIM, CA 92802 • TELEPHONE (71 4) 635-4055 • • • • 20 Years of Service • • • • Circle 202 on inquiry card. BYTE September 1980 285 APPLE n OR APPLE n PLUS Shipped direct to you! (Plus Shipping) We have orchard fresh Apple products ready to ship. Immedi- ate delivery. Send cash or cashiers check for quick ship- ment. Orders with personal checks shipped after bank clearance. 16K UNITS $899 32K UNITS $999 48K UNITS $1099 Apple Disk Drive $550 Pascal Language Card $450 Above plus $20 shipping charge. IMPORTANT— No shipments made with- in the state of Illinois. MIGHTY MICROS I P.O. BOX 11375 CHICAGO, IL 60611 ORDER Enclosed $- For FORM _Via U.P.S. Shipto:_ Name Address- (No P.O. Boxes-Street Address Only) City- state. -Zip- disable signal to IC4. By momentarily bringing this line low, the current in- terrupt is dismissed, and further inter- rupts are enabled. However, if this line is held low, all clock interrupts are inhibited until pin 1 of IC4 is once again a logic 1. The other connection is made between pin 6 of IC4 (Q ) and one of the interrupt inputs of the computer, line 1 in this case. This line signals the processor that an interrupt has been requested by an external device, and is active low. Software The software necessary to drive the real-time clock is shown in listing 1. To set the time of day and enable the ( STIM J GET ADDRESS OF WHERE TIME IS KEPT, PLACE IN RO INCREMENT RETURN ADDRESS MOVE VALUE TO HOURS, INCREMENT ADDRESS RO MOVE VALUE TO MINUTES, INCREMENT ADDRESS RO YES MOVE VALUE TO SECONDS ZERO HOURS, MINUTES, AND SECONDS INITIALIZE RATE TIMER, ENABLE CLOCK INTERRUPTS f RETURN J Figure 3: Flowchart of procedure that sets the clock. 286 September 1980 © BYTE Publications Inc Circle 203 on inquiry card. Circle 204 on inquiry card. INTRODUCING iiiiiifnfiFsiiiii MULTIPLE APPLICATION PROCESSING SYSTEMS MP/M "USERS GROUP Digiac Corporation, a major manufacturer and supplier of automated Educational Training Systenns, is proud to announce the formation of MAPS, a National MP/M Users Group which will provide all MP/M users with a vehicle to exploit MP/M's benefits. MP/M SUPPORT PRODUCTS DIgiac is supporting MP/M with a series of exclusive S100 products: • Universal MP/M Support Module • MP/M XiOS Configurations for popular Disk Systems • MP/M Multibank Memory Module • CT-80 Multi-Workstation System For Additional Information: f^ a> Contact Lorraine Keckeisen ( -J ® MAPS Commercial Products Div. DIGIAC CORPORATION 175 Engineers Road Smithtown, New York 11787 ^^^^^^^^ ^ Phone (51 6) 273-8600 CORPORATION MP/M is a trademark of the Digital Research Corporation DIGIAC DIGITAL GROUP products are available through AEON Elec- tronics in Denver, Colorado. We carry the complete line of cabinets, printers (Spinwriter &■ B-Printers), Disks (Shugart), Single &■ Double Density Controller Cards, Memory Cards, Z-80ACPU 2.5/6Mh2, Communications Card (for terminals &■ Modems), and Peripheral Boards. All items are from stock. Bare Communications Card Comm 4 Pec $65.00 32k Static Mem. Board/Sockets, Decoding IC's Mem 320 $85.00 1/0 Card/4 Port in Ef out lO-F $50.00 Double Density Bare Card & Doc BDD $95.00 D.G. Dress Mainframe Cabinet/metal only CB $85.00 D.G. Dress Cabinet/metal plus Electronic Hardware CB-CPU $185.00 D.G. Disk Cabinet/In Stock!! DSSCB-2 $165.00 ^EOINI Manufacture of Digital Group Computers 1855 S. Pearl Denver, Colorado 80210 Phone Orders 303-777-AEON THE CONFIGURABLE BUSINESS SYSTEM' THE ONLY COMPLETE APPLICATION DEVELOPMENT SYSTEM • No Programming Experience Necessary • User Definable Records Up To 2K Bytes • Powerful Report Generating Capabilities • Built-in, Self -reorganizing ISAM File Structure • Interactive and Batch Information Processing • Packed Fields For Efficient Disk Utilization • System Completely Menu Driven • Fast Execution - All Programs in 8080/Z80 Machine Code • Easily Configured to Your CRT • Field Proven • Comprehensive Users Guide • Supplied On 2-8" CP/M* Compatible Disks DISKS AND MANUAL $295.00 MANUAL ALONE ... $ 40.00 Dealer Inquiries Invited •CP/M is a Trademark of Digital Research Corp. Phone Orders Accepted N.Y. Residents Add 7% Sales Tax Dymaxmic Microprocessor Associates f 36 Pinewood Drive Commack, N.Y. 11725 (516) 543-6006 Circle 205 on inquiry card. BYTE September 1980 287 Make America smarter. Give to the college of your choice. Ifoucan now order article reprints from this publication University iVIicrofllms International, in cooperation with publishers of this journal, offers a hrghly con- venient Article Reprint Service. Single articles or complete issues cein now be obtained in their original size (up to 8V2 x 1 1 inches). For nnore information please com- plete and mail the coupon below. ARTICLE REPRINT SERVICE University Microfilms International n YES! I would like to know more about the Article Reprint Service. Please send me full details on how I can order. D Please include catalogue of available titles. Name . Title Institution/Company Deparlment Add res s Cily Stale _ Mail to: University Microfilms International Article Reprint Service 300 North Zeeb Road Ann Arbor, Michigan 48106 clock hardware, a call is made to the entry point STIM. This call instruc- tion is followed in memory by the address of the memory location where the time of day may be found. This address pointer is placed into register RO and the return address set by the first line of STIM code. The value to be used for hours is then compared to the maximum value allowed (eg: 24 for a 24-hour clock). The same sequence of events occurs for both the minutes and seconds values. If the number to be used is greater than the maximum allowed or is negative, no further testing is done. Instead, the clock is cleared, the hardware is enabled, and a return is made to the calling routine. The calling routine must then set the interrupt mask to allow inter- rupts at the chosen level. To obtain the time of day, a call to the GTIM routine is made. The call instruction is followed by the address of the memory location where the time will be stored. To access the interval timer, the entry points of STCLK and RDCLK are used. STCLK will reset the timer to 0, and RDCLK will place the cur- rent value of the interval timer into ( GTIM j GET ADDRESS OF WHERE TO STORE TIME INCREMENT RETURN ADDRESS MOVE HOURS INCREMENT ADDRESS RO MOVE MINUTES INCREMENT ADDRESS RO MOVE SECONDS ( RETURN J the caller's RO. When the clock hardware generates an interrupt, control is transferred to ( CKINT J RESET/DISABLE INTERRUPTS INCREMENT INTERVAL AND RATE TIMERS ZERO RATE INCREMENT SECONDS COUNT ZERO SECONDS INCREMENT MINUTES COUNT ZERO MINUTES INCREMENT HOURS COUNT ZERO HOURS I DISMS I ( I I RE-ENABLE INTERRUPTS ( RTWP J Figure 4: Flowchart of routine that reads Figure 5: Flowchart of procedure for deal- the clock. ing with a clock interrupt. 288 September 1980 © BYTE Publications Inc 64K MEMORY FOR THE HEATHKIT H8' COMPUTER Circle 206 on inquiry card. Assembled $750 615 480 345 Kit $650 525 400 275 64K (56K) 48K 32K 16K l\Aemory Expansion Kit - 16K $125 PC Board Only - With Documentation $ 50 Phone for Free Brochure 714/830-2092 *HEATHKIT and H8 are Registered Trademarks of the Heath Co. — TRIONYX ELECTRONICS BOX 5131-C, SANTA ANA, CA 92704 DISK DRIVE WOES? PRINTER INTERACTION? MEMORY LOSS? ERRATIC OPERATION? DON'T BLAME THE SOFTWARE! ISO-l "\) ISO-2 Power Line Spikes, Surges & Hash could be the culprit! Floppies, printers, memory & processor often interact! Our unique ISOLATORS eliminate equipment interaction AND curb damaging Power Line Spikes, Surges and Hash. ♦ISOLATOR (ISO-1A) 3 filter isolated 3-prong sockets; integral Surge/Spike Suppression; 1875 W Maximum load, 1 KW load any socket $56.95 ♦ISOLATOR (ISO-2) 2 filter isolated 3-prong socket banks; (6 sockets total); integral Spike/Surge Suppression; 1875 W Max load, 1 KW either bank $56.95 ♦SUPER ISOLATOR (ISO-3). similar to ISO-1 A except double filtering & Suppression .... $85.95 ♦ISOLATOR (ISO-4), similar to ISO-1 A except unit has 6 individually filtered sockets .... $96.95 ♦ISOLATOR (ISO-5), similar to ISO-2 except unit has 3 socket banks, 9 sockets total . . . $79.95 ♦CIRCUIT BREAKER, any model (add-CB) Add $ 7.00 ♦CKTBRKR/SWITCH/PILOTany model (CBS) Add $14.00 PHONE ORDERS 1-617-655-1532 "gf /S^ Electronic Specialists, Inc. 171 South Main Street. NatlcK. Mass. 01760 Dept.BI A REFURBISHED "SELECTRIC" ASCII TERMINAL FOR THE SMALL BUSINESSMAN OR SERIOUS HOBBYIST TheAJ841I/OtenninaL Now available from dealers nationwide. Demand for our AJ 841 I/O computer terminal has been great. And now it's getting even greater. So call your local computer shop dealer right away. Supply is limited! You may never have another opportunity like this one to buy your own professional terminal. The A J 841 features: • Choice of serial RS 232 or parallel interface • ASCII code • 14.9 cps printout • High quality Selectric printing • Heavy-duty Selectric mechanism • Off-line use as typewriter • Documentation included • 30-day warranty on parts and labor (details available on request) Call toll-free now For location of your nearest AJ dealer, call toll-free: 800/538-9721 California residents call 408/263-8520. Circle 207 on inquiry card. BYTE September 1980 289 the entry point CKINT. The interrupt less then 0, interrupts are reenabled reenabled and the interrupted pro- is then reset, and further clock inter- and the interrupted program re- gram resumed, rupts are inhibited by holding the sumed. If the result is greater than or clock line of the communication equal to 0, the rate counter is reset to Conclusion register unit low. Next, the interval and the seconds counter is incre- The method presented in this arti- timer is incremented, as is the rate mented. The same process that was cle will allow users a flexible and in- counter. The rate counter is then used for the rate counter is then ap- expensive way to maintain the time of compared to the basic clock frequen- plied to the seconds, minutes, and day on their personal computer with cy. If the result of the comparison is hours counters. Lastly, interrupts are low software overhead. ■ Listing 1: Routines that keep time using the real-time clock, written in assembler for the 9900 microprocessor. ♦♦♦♦♦♦♦♦♦♦♦♦♦♦♦♦♦♦♦♦♦♦♦♦♦♦♦♦♦♦♦♦♦♦♦♦♦♦♦♦♦♦♦♦♦♦♦♦♦♦♦♦♦♦♦ ♦ ♦ THIS IS M RERL TIME CLDCK DRIVER PRDGRRM FDR THE ♦ TEXRS INSTRUMENTS TMS99i:iLi MI CRDPRDCESSDR- ♦ I.IRITTEN by: TDM G. MDRRIS ♦ 861 ST- MRRY RVE ♦ SRN LERNDRD. CR 94577 ♦ TD ESTRELISH THE CDRRECT TIME DF DRYj ISSUE ^ R CRLL TD STIM. E.G. EL i'STIM ♦ DRTR TDD ♦ MHERE TDD PDINTS TD RN DUTLINE LIST THRT ^ CDNTRINS THE TIME DF DRY IN THE FDRMRT ♦ TDD HDURS ♦ TDri-»-l MINUTES ♦ JUl\ + d SECDNDS ♦ IF RNY DF THE VRLUES RRE INVRLIIn THE TIME IS ♦ SET T D M I UN I GHT < U U : U U : U WO . ♦ ♦ TD DETRIN THE CDRRECT TIME DF DRY;. ISSUE ♦ R CRLL TD GTIM. E.G. EL i'GTIM ♦ DRTR TDD ♦ ♦ UHERE TDD PDINTS TD RN DUTLINE LIST UHERE THE ♦ CDRRECT TIME DF DRY MILL EE STDRED. SEE REDVE. ♦ ♦ RLSD RVR I LRELE TD THE USER IS RN INTERVRL TIMER ♦ THRT INCREMENTS RT THE INTERRUPT RRTE^ RND ♦ IS RESET EY R CRLL TD STCLK. E.G. EL i'STCLK ♦ ♦ TD RERD THE INTERVRL TIMER. ISSUE R CRLL TD > RDCLK. E.G. EL i'RDCLK ♦ ♦ THE CURRENT VRLUE DF THE TIMER MILL EE RETURNED ♦ IN THE USERS Ru. ♦♦♦♦♦♦♦♦♦♦♦♦♦♦♦♦♦♦♦♦♦♦♦♦♦♦♦♦♦♦♦♦♦♦♦♦♦♦♦♦♦♦♦♦♦♦♦♦♦♦♦♦♦♦♦ ♦ TITL RERL TIME CLDCK DRIVER- UUUU RTC IDT ♦ ♦ DEFINE INTERRUPT VECTDRS ♦ ULIU4 RDRG >i:iLiU4 i:iLiU4 LirifiU DRTR RTCMS ; l-JDRKSPRCE PD INTER OOUt. i:iU74 DRTR CKINT ; INTERRUPT HRNDLER ♦ ♦ DEFINE LINKING :<: REGISTERS ♦ OUUU RDRG ♦ U U U U DREb Listing I continued on page 292 290 September 1980 © BYTE Publications Inc Circle 208 on inquiry card. Circle 209 on inquiry card. Reliable Business Bookkeeping Software ORDER ENTRY MICROSOFT CP;Mp, PET, APPLE !l, MICROPOLIS: $350/ea. GL, A/P, A/R, INVENTORY, PAYROLL TRS«80 MOD 1: $100/ea. CBASlC-CP/Mp: $200/ea. ATARI, PET, APPLE II, TRS-80 MOD II, MICROPOLIS, VECTOR, EXIDY, DYNABYTE, CROMEMCO, MICROSOFT CP/Mp: $140/ea. They all work together! Buy simple, effective programs designed specifically for your machine. Call us once for same week delivery on a product you can use the day you receive it, and two years from now when your company Is twice as big. Order today by U.P.S. COD. We'll pay postage and handling on Am. Ex., Visa, Mastercharge, or pre- paid orders. 467 HAMILTON AVE. PALO ALTO, CA. 94301 TRS-80* EQUIPMENT 16K MEMORY KITS $49.95 4116's 6 MONTH WARRANTY INSTRUCTIONS INCLUDED DISK DRIVES 40 TRACK — $325 2-DRIVE CABLE 77 TRACK — $475 24.95 PRINTERS MICROTEK MT80P BI-DIRECTIONAL 125 CPS UPPER & LOWER CASE 1 YEAR WARRANTY $695 CABLE — 24.95 DISKETTES MEMOREX OR BASF 10/26.50 YOUR SATISFACTION GUARANTEED OR FULL REFUND MICROCOMPUTER SERVICES CORPORATION 7314 MATTHEWS-MINT HILL RD. CHARLOTTE NC 28212 704-545-0826 TRADEMARK TANDY/RADIO SHACK CORP C!:^ PERSONAL COMPUTER SHOW AND FLEAMARKET -80 1 Saturday, Sept. 27 9:00 AM — 6:00 PM g^ Sunday, Sept. 28, 1980 10:00 AM — 4:00 PM COMMERCIAL EXHIBITS I OUTDOOR FLEAMARKET RAIN OR SHINE HOLIDAY INN (North) CONVENTION CENTER at Newark International Airport (Exit 14 NJ Turnpike— Take Service Road) ADMISSION $4.00 in advance— $5.00 at Door FOR REGISTRATION, EXHIBITOR OR FLEAMARKET INFORMATION CONTACT. N.J.P.C.S. Kengore Corporation 9 James Avenue Kendall Park, NJ 08824 USER FORUMS Circle 210 on inquiry card. BYTE September 1980 291 Listing 1 continued: DEFIME EMTRY PDIMT:: Ij LI LI LI LI LI 04 LI U Lib LI LI ut; ULIUH LILMJC UULlE Liu:Z:C LI LI 1 LI LI LI 1 8 LI LI 1 c' LI LI LI 1 LI LI 1 4 LI LI 1 y LI U U U LI LI 1 M UL Lie' LIL LI 3 LIL 04 IJL 05 LIL 06 LIL 07 LIL 08 iJL 09 ML OF U Oc u OOc'O 04E0 OOc'4 0451: ♦ RTCWS RRTE SECS MlhS MRS TIMER SIXTY TFGUR HERTZ riEF STCLK.RDCLK.STIM DEF i3TIM!.CKIMT THE FGLLOUIMG PhRhMETERS WILL BE MHlMTHlMEn IM THE PTC UDRKSPHCE RPEH vHED IChTErO E:::S 4 ESS -a BSS c! BS:S -d ESS d ESS £ DHTh 6 DhTH c'4 DHTH 1 ESS 4 DHTH ESS 6 PTC I.IDPK ::PRCE • NE XT I'd LDCx.:' IMTERMHL TIMER SECnMIiS MINUTES HDUP::: IMTEPVhL TIMER MINUTES-- ^ECDNIi:: ; C HEi: ::K HOURS CHECK SET TD INT. RRTE a. 10? 6 0::' RlO-Pl 1 Rlc' CPU ERSE R13-P15 ♦ ♦ THE ♦ SINC ♦ DVER XPRTE >::sEcs XMIMS XHPS XTIMEP XSIXTV XT FDUR XHERTZ CLGCK ♦ STCL STCLK FGLLGUING EQUIVRLENCES RRE USED E THE INTERRUPT HRNDLING WGRKSPRCE LRVS THE VRRIRELE STGRRGE RRER EQU EQU EQU EQU EQU EQU EQU EQU EQU R2 R5 R4 R5 R6 R7 RS R9 15 ; IMTERNRL ; SEC GNUS ; MINUTES ; HGURS ; INTERVRL TIMER TIMER ; CLGCK CDNSTRNT:: ; INTERRUPT ; CLOCK CPU FREQUENC GFFSET K: reset the INTERVRL TIMER TG ZERG EQU 'i CLP i'TIMER E ♦Pll ;CLERR TIMER ; RETURN TG CRLLEP LI Ucb 8 6 C08 08R 04 5E y ♦ PnCLK pnCLK EQU MGV E RETURN TIMER VRLUE TG CRLLER IN RO :iiT I MER-.ro ♦ Rll ;PLRCE TIMER INTG ; RETURN TG CRLLER R no8C 08C r 08E r 0:::!8 r 036 L M03R L 03 E C8 C8 48 45E LMJUH 08 \\ Of' ♦ GTIM: get the TIME GF DRV GTIM EQU MGV r-IGV MGV ♦ Rl 1 + !.R0 ;i'HRS!.^RO+ ;JMINS!.^RO + MGV •i'SECSi.^RO E ♦Rll ;get RnriR pntr;. return ;STGRE HGURS ;STGRE MINUTES ;STGRE SECGhUS ; RETURN TG CRLLER RnriR ]:TIM: set THE TIME GF DRV RLSG. ENRELE THE RERL Listing 1 continued on page 294 292 September 1980 © BYTE Publications Inc Circle 211 on inquiry card. Circle 212 on inquiry card. ^ MYCHESS ^ Winner of 5th West Coast Computer Faire Micro-Chess Tournament MYCHESS Atari Atari Boris/Sargon 2.5 Voice Challenger 31/2 21/2 2 11/2 1 USCF rating 1568 (June Supplement) from over 60 rated games - highest ever any micro-program. • Will save game on disk for later play • Set up any position •9 levelsof play- Will solve any niate-in-5 problem • Z80 Assembly program •Will display best line of play • Searches on opponent's time • Over 850 opening moves •Tournament time control • Will print game out when over Available for CP/M®, CDOS®. North Star®, (CP/M®, DOS®) $50.00 Computer Services 2431 Lyvona Anchorage, AK 99502 APPLE-TIME $1^0 For Your APPLE,,, The Ultimate CLOCK/CALENDAR Board MORE FEATURES FOR LESS • 12 or 24 HR Format • Perpetual Calendar MM DD YY • Crystal Controlled Time Base • Ultra Fast Time/Date Setting • 4 Interrupts Available • Months Of On-Board Batten/ Backup Setit& forget it. MANY MORE FEATURES TSR80 & S100 MODFIS AVAK ABLF TSR80 is a Trademark of Radio Shack a Div. of Tandy Corp. Apple is a Trademark of Apple Computer Inc. ©Compu/Time ^ , Squires. PO. Box 5343 i^eaier inquire*. Huntington Beach. Co 92646 (714)536-5000 Makers Of Qualify Low Cost Microcompufer Componenfs ^ ► ^ • CP/M®' - based Business Software forTRS-80®^ computers on . . . the fastest Mod-ll CP/M with the most features!!! • Over 610,000 bytes/disk • Downloading package included • 1 ,200 baud operation of serial printers without data loss • Single drive backup MOD-II CP/M $250.00 • Mixed single/double density on any of 4 drives (even a 1 -drive system) • Ultra-fast disk operation • Emulation of cursor addressing for any of several "dumb" CRTs MOD-ICP/M $150.00 • Auto-LF printer support & ASCII top-of-form software (LPIII) • Supplemental document describing our implementation • User-settable function keys CBASIC2®3(Mod I or II) $110.00 The following software for Mod-ll CP/M only unless o RM/COBOL®^ - Only COBOL for CP/M with alternate keys (multi- keylSAM),CRT screen handling, interactive debug.ZSOcode.and the most useful Level 2 features. Compatible with Tandy's COBOL-but runs faster! $495.00 PMS (Property Management System) - Interactive, menu-driven system includes full G/L, budgeting, cash journal, delinquency list, tenant activity/rent roll, complete audit trail and reports on vacancies, lost rent, and vendors $650.00* demo disk & manual 75.00* APH (Automated Patient History) - General-purpose question- asking, answer-printing system furnished as self-administered review-of-systemsgeneral patient history (Mod-I also) ... $175.00* therwise stated (*-requires CBASIC2): MAGIC WAND®5 - Full-feature word processing, true proportional spacing, file merging, and use of full-screen editor for source programs or data $400.00 RPA(Residential PropertyAnalysis)-Analyzesincomeand expense, financing, taxes, inflation and depreciation on home, condo, or apartments over a user-selectable time. Shows payoff in terms of ROI, Cap rate, cash-on-cash. Amortization schedules and worksheet $300.00* demo disk & manual 35.00* RBC (Rent/Buy Comparison) - Sales or investment tool to compare renting and savings account investment vs. purchasing a particular property $250.00* demo disk & manual 35.00* Osborne & Assoc. CBASIC source programs (Mod-I also): Payroll w/Cost Accounting $250.00* General Ledger w/Cash Journal $250.00* Accts. Payable/Accts. Receivable $250.00* O&A CBASIC Books (ea.) $ 20.00 \feit)atim®^ media: (Qty. 100 prices) 574" single density $2.50 ea. 8" certified double density $4.00 ea. 8" single density 450' tape cartridges $ 3.00 ea. $20.00 ea. 8041 Newman Ave., Suite 208 ^ Huntington Beach, CA 92647 (714)848-1922 Registered trademark of; ®^ Digital Research ®2Tandy Corp. ®3Compiler Systems, Inc. ^'^Ryan-McFarland Corp. ®^Small Business Applications, Inc. ®^Verbatim Corp. 1^ Distributed in U.K. by: Microcomputer Applications Ltd, 1 1, Riverside Court, Caversham, Reading, England TEL: (0734) 470425 BYTE September 1980 293 Listing 1 continued: TIME CLDCK, U 3C :^:Tiri EQIJ :i; 3 C C: 1 j >: I: MD'v' ♦Rll-^iRO ;bET RDDR PhTR.RETURM UU3E 8810 1 f: ♦ RO.i'TFDUR ; CHECK HDUR:::: Ou4c' 1411 J HE CLERR ; IMVRLID. CLERR: CLDCK 044 C83 OR MDV ♦RO-J-iiiiHR::-: ;:::ET THE HDUR:!-: 048 8810 OOOE f: ♦ RO?i':S:i::aY ; CHECK MI MUTES 0411: 14 011: J HE CLERR ; IMVRLID. CLERR CLDCK 04E i::8::-:0 08 MDV ♦ RO-^-^iiiMIM::: rSET THE MI MUTE::: 05c' :88; 1 ij OE f: ♦RO?:ii:^:lXTY ; CHECK :!::ECDr-iriS 056 14 07 JHE CLERR ; IMVRLID. CLERR CLDCK 058; i::81 06 MDV ♦RO!.ii:iECS ;:!::ET THE SECDNHS 05C RTRh EQIJ :i; 05C 04i::i:: CLR R18 ; PRESET CRU ERSE 05E 04E0 04 CLR JRRTE ; IMITIRLIZE RRTE 068' in OF :S:BD CLDCK ;emrble rerl time cld 064 04 5 E B ♦ Rll ;returm td crller 066 CLERR EQIJ :i; 066 04E0 OR CLR i'HR:^: ; CLERR DUT THE CLDCK 06H 04E0 08 CLR :i'MIM:S: 06E 04E0 06 CLR *i:SEC:S: 078 1 0F4 .jr-iF- RTRh ;EMRBLE CLDCK-. RETURM THI S IS THE MRIh IhTERRIJPT HRMDLIMG SECT I DM. ♦ HERE THE TIME DF BRV IS KEPT. RLDhb I.IITH THE ♦ IMTERVRL TIMER, 074 CK INT EQIJ :i; 074 IE OF :i:BZ CLDCK ;riISRBLE.-RESET 076 05 tit. ir-ic XT I ME R ;UPDRTE TIMER 1 J 1 J 7 '8 058:8 IMC XRRTE ; IMCREMEMT IMTERVRL 07H 8848 C XRRTE.XHERTZ ; CHECK RbRIMST FREQ- 07C 1 1 on JLT D I S\'\S ; DISMISS ir-IT 07E 0408 CLR XRRTE ; RESET RRTE 8i 1 j 058:8 Ir■^c X:SEC:S iSECDMDS CDUMT 088 81i:::8 f: XS:EC:::.X:::I:KTy 084 1 1 09 JLT Bisr^s 086 04 Co CLR X:S:EC:S: ; RESET SECDMDS 088 0584 IMC XMIN:i: ;MIMUTES CDUMT 08H 8104 f: XMIh:::.X:S:IXTY SO 1 1 05 JLT DI:S:N::: 08E 0411: 4 CLR XMIh:i: RESET MI MUTES 09 058:5 IMC XHR::: HDURS CDUMT 098 88 05 f: XHR:!::.XTFDIJR IJ94 1101 JLT DISM:S 0LI96 0405 CLR XHR:i: .RESET HDURS 098 ni :SN:S EQIJ :i; 098 moF ;S:BD CLDCK EMRBLE IMTERRUPTS 1 j 1 j 9 R 088 RTI.IP RETURM TD IMT. LDC. RDDR EMD 074 ♦ 1 8 ♦ 00 OR ♦ I j I j I j F 1 j I j I j 6 ♦ 0086 OOOE I j I j I j 9 I j I j I j 7 DUTPUT CKIMT HERTZ R 1 R15 R6 RDCLK SIXTY xhert: XSIXT'- RERD'- Ut't. OOR OOE 08 07 Ij I j I j 08 05 08 CLERR HRS Rl 1 R8 R7 RTC STCLK XHRS XTFDUR OF 08 OOC 0:Z: 08 1 j I j I j 0:3C I j I j 4 ij ij f. CLDCK MI MS R18 R::-; R8 RTCUIS STIM XMIMS XT I ME R 098 1 j I j ► OOOD 04 0'? 05C 1 08 DISMS RO R 1 3 F:4 R9 RTRM TFDUR XRRTE ♦ 08C ♦ I j I j IJ 1 ♦ Ij I j E 05 1 j I j 4 06 OOOC 1 j ij ij : -: GTIM Rl R14 R5 RRTE SECS TIMER XSECS Listing 1 continued on page 296 294 September 1980 © BYTE Publications Inc Circle 213 on inquiry card. Circle 214 on inquiry card. SuperBrairi Software. A/R A/P G/L P/R Inventory Restaurant Payrol Mailing List Word Processing MICROSOFT C-BASIC PRICE X X $250.00 X X $250.00 X X $250.00 X X $250.00 X X $250.00 X $250.00 X $150.00 X $195.00 ^'Industry Standard" programs on 5V4" diskette include source and complete profes- sional documentation. Ready to run on Super- Brain.® One time charge, non exclusive license. Also SuperBraIn computers check on prices. QC3Q IVIARKETMMG 116 South Mission Wenatchee, WA 98801 (509) 663-1626 Ask for wholesale division ® Trademark of Intertec Data Systems WE CAN'T WAIT FOR EVERYONE ELSE TO CATCH UP! While other software dealers only promise TAX SOFTWARE in the future - CPAJds has it NOW! And we've even added more schedules! MASTER TAX PACKAGE: Schedules - A, B, C. D, E, F, G, R/RP, SE. TC. ES. Forms - 2106, 2119, 2210, 3468, 3903, 2441, 4625, 4726, 4797, 4792, 5695, 6521. Available on North Star and most CP/M compatable 8" soft sector computers. Trust CPAids, the people who started it all. Like you, we just couldn't wait any longer. Call Toll Free 800-321-2430 G>1iDS (5) 1640 Franklin Ave. • Kent, Ohio 44240 S^^:^^ master charge A IMEW CONCEPT BE^AFIPLE ][* SOFTWARE Finally, a company specializing in software for the APPLE! [or] [ Plus and only APPLES! All your software shopping can now be done under ONE ROOF at TREMENDOUS SAVINGS! Because we sell software and only software, we receive discounts from ALL major Suppliers, such as: HAYDEN CREATIVE COMPUTING PERSONAL SOFTWARE PROGRAMMA MICROSOFT and MANY OTHERS and WE CAN PASS THESE SAVINGS ONTO YOU, the APPLE USER! If you are tired of page thumbing looking for APPLE programs, and want the best prices on ALL programs written for the APPLE, send for our FREE 40-page catalog and a $1 coupon good towards your first order or call us for our price on any APPLE program written and order by phone. M/C, VISA, BankAmericard ac- cepted. IF WE HAVEN'T GOT IT, IT HASN'T BEEN WRITTEN!! -Trademark ol apple computers mc. Software Concepts 948 Danvers Ave., Westerville, OH 43081 (614) 882-8007 Hours: 10AM-9PM Weekdays 12Noon-5PM Saturdays Closed Sundays NEW PRODUCTS Lo-Res Graphics Pads Verbatim 5" Diskettes CASTLE ADVENTURE! $ 1.75/ea. $2.65/ea.(Quan 1) $17.95/disk Circle 215 on inquiry card. BYTE September 1980 295 Listing 1 continued: U U U U U R T l: M U U U U 9 U U U 4 C: ij ij ij ij C: U U 7 4 M ij ij ij E E U U 3 C: E U U 1 8 E U U U 1 M U U 1 8 E ij ij ij ij M U U c' U 7 F 1 F 6 F E 4 E U l: U U U l: E U 4 5 E E C: U d U C: U U U C: E U 4 5 E E C: U 3 E E C: C: d U C: U U U M E C: C: d U C: U 8 E C: 4 c! C: U 6 7 F 1 7 U F E 4 5 E E l: U 3 E E 8 8 1 C: U 1 U E 1 4 1 1 E C: 8 3 U C: U U U M E 8 8 1 U C: U U U E E 1 4 C: E C: 8 3 U C: U 8 E 8 8 1 U 7 F 1 M E F II: U U U E E 1 4 7 E C: 8 1 U C: U 6 E U 4 C: C: E U 4 E U C: U 4 E 1 H U F E U 4 5 E E U 4 E U C: U U U M E U 4 E U C: U 8 7 F 1 8 F F E i:i4E iJC Ij Ij IJ6E 1 IJF4E 1 E UFE IJ586E iJ58c'E8c'4c'E 1 1 IJHE iJ4i::c'E IJ583E8 1 i::3E 1 1 IJ9E iJ4i::37F 1 93F E IJ584E8 1 i::4E 1 1 IJ5E iJ4i::4E iJ585E8c' IJ5E 1101 E iJ4i::5E 1 H UFE IJ38 IJ5 ij iJ74i::K I MT 5 U iJc'CGT I M 7EFri8F 5UUc:6Rrii::LK SUUclUSTCLK 5UU3i::STIM 090 7F610F EriIT.-HSM-.-LDfiD? Listing 2: A program to demonstrate the use of the real-time clock. ♦♦♦♦♦♦♦♦♦♦♦♦♦♦♦♦♦♦♦♦♦♦♦♦♦♦♦♦♦♦♦♦♦♦♦♦♦♦♦♦♦♦♦♦♦♦♦♦♦♦♦♦♦♦♦ ♦ ♦ riEMDMSTRRTIDM PRDGRRM FDR THE ♦ TIME DF riRV CLDCK RDUTIME ♦ ♦ I.IRITTEM EV: TDM G. MDRRIS ♦ 861 ST. MRRV RVE ♦ SRM LERMriRD;. CR 94577 ♦ ♦ DEMDMSTRRTES THE USRGE ♦ DF THE RTC SDFTI.IRRE ♦ ♦♦♦♦♦♦♦♦♦♦♦♦♦♦♦♦♦♦♦♦♦♦♦♦♦♦♦♦♦♦♦♦♦♦♦♦♦♦♦♦♦♦♦♦♦♦♦♦♦♦♦♦♦♦♦ TITL -RTC riEMDMSTRRTIDM- 000 EX IDT IDT ♦ ♦ riEFIME LIMKIMG n, REGISTERS ♦ 000 RDRG ♦ 000 DREG ♦ ♦ DEFIME EXTERMRLS n, EMTRV REF STCLhSRHCLK REF STIM.GTIM REF RTC 1 HID DEF EXMPL ♦ £1148 niM nXDP 5 ;riECIMRL INPUT £1188 DDUT nXDP 6 ;riECIMRL DUTPUT ♦ STDRRGE FDR TIME DF DRY ♦ 000 HRS ESS: d ; HDURS 0c: MI MS ESS d ; MINUTES 04 SECS ESS d ; SECDNHS 06 TICKS ESS d ; INTER VRL TIMER ♦ ♦ TEXT STDRRGE ♦ S n R C R L F E V T E > H ;. > R ;. E n OR N E S S E Y T E > D ;. > R OOOn 454E 5445 TEXT -^EMTER TIME DF HRV (HH : MM : SS;:- ^- 0011 5c'c'0 5449 0015 41145 c'04F 0019 46c' 4441 001 n 59c: £848 IJ U c 1 4 8 -j! R 4 n 4 n 1 ,5f ,-„g 2 continued on page 2 98 296 September 1980 © BYTE Publications Inc Circle 216 on inquiry card. Circle 217 on inquiry card. ANNOUNCING: NEW! MICROSTAT A complete statistics package for business, scientific, education and research work. No other package has the features of M ICROSTAT. For example: • File oriented with COMPLETE editing • A Data Management Subsystem for editing, sort- ing, ranking, lagging, data file transfers PLUS 11 data transformations (e.g., linear, reciprocal, exponential, etc.) • Frequency distributions • Simple and multiple regression • Time series (including exponential smooth- ing) •ll Non-parametric tests • Crosstabs/Chi-square • Factorials (up to 1,000,000!), permutations, combinations • 8 Probability distributions • Scatterplots • Hypothesis test (Mean, proportion) • ANOVA (one and two-way) • Correlation • Plus many other unique features Users manual: $1 0.00 (credited towards purchase) and includes sample data and printouts. Uses NORTH STAR BASIC 32K of memory, one or two disk drives (2 recommended). Printer optional. Price: $200.00 1 ECOSOFT . ■[master charge P.O. Box 68602 Indianapolis, IN 46268 Phone orders: (317)253-6828 FLOPPY DISK FACTORY DIRECT FLOPPY DISK FACTO < D 1} m n DC o CJ < LL :^ in Q >■ CL D_ o i- CJ LU DC Q > DC O h- < LL Q > CL CL O U LU Q > CE O I- < • Buy factory direct from the manufacturer of floppy disks sold exclusively under other well-known brand names, • Save distribution costs on reversible 5.25" floppy disks, which are 1 00°/o certified for 40 track, dual side, double density and all other standard applications. • 50°/o savings on 5.25" floppy disks with new factory- direct 2.2 megabyte capacity "Diskit". • Factory-direct "Diskit", includes twelve floppy disks and accessories, plus a head cleaner disk and solution packaged in a bookcase binder for easy access, handling and Storage. "Diskit" complete for the introductory price of only $49.50 plus $2.50 freight and handling. Normal price $59.50. Order nouw and save S10.00 [CA residents add BV2°/o sales tax]. • Available in hard and soft sector configurations; when ordering indicate number of sectors — 1 , 1 or 1 6. • Send check or money order to: Factory Direct P.O. Box 60759 Sunnyvale, CA 940BB For VISA or MasterCard call toll-free (800) 824-7888 In Calif. [800] 852-7777 In Alaska & Hawaii (800) 824-791 9 Ask for Operator 98 d >1SIG AddOld lG3U!a Aa013\/d MSIQ AddOld 13 O "D "D -< D CD 7^ -n > n H O XI -< D XI m n o -< D cn 7^ -n > n H O X -< D X m kroif s Mapper + NEWDOS/80 8 Drives for theTRS-80 NEWDOS/80 is Apparat's latest upgrade to NEWDOS. Features include variable length records, chaining, and drivers specifically con- figured for Omikron's MAPPER II. $150. MAPPER li adapts the TRS-80 to run both 5" and 8" drives. With NEWDOS/80, storage is increased to 300K per 8" drive. $99 plus $10 per cable connector. MAPPER I adapts the TRS-80 to run the vast library of CP/M software as well as the TRS-80 software. All Lifeboat Software may be ordered for the MAPPER I. All MAPPER I CP/M soft- ware is compatible with the CP/M for the Model II. With MAPPER II and 8" drives, the Model I becomes disk compatible with the Model II. Standard features include lower case support, serial and parallel printer drivers, and an ad- dressable cursor. MAPPER I is supplied with complete utilities including a memory test, a disk test, a copy program, and a proprietary program for converting TRS-DOS files to CP/M files. $199. WORD PROCESSING- MAPPER I supports professional word processors like the Magic Wand and Word Star (see reviews in June 80 Kilobaud). Omikron's implementation includes a blinking cursor, auto repeat, shift lock, de- bouncing, and an input buffer that eliminates missed characters. Magic Wand super discount price $299. FIELD PROVEN DESIGNS- After one year of MAPPER production, Omikron has established an impeccable reputation for reliability , integrity, and user support. Omikron's customers include the US Government, major corporations, uni- versities, medical doctors, and professionals in all fields. SYSTEMS — Omikron sells complete systems featuring Model II compatible Shugart disk drives. Call for prices and delivery. FOREIGN ORDERS must include full payment in US funds plus $25forair shipping and handling. See review in July 80 BYTE By Jerry Pournelle. *CP/M is a TM of Digital Research. TRS-80 is a TM of Tandy Corporation. Circle 218 on inquiry card. EYTE ij BYTE > Ull!«> UM TEXT •THE MUMEER Listing 2 continued: UUE'? 3m53 5329 OUc"? c'USF IJUE'E iJU riricT: UliUM MESSl iJUclE 5448 45c: U TEXT ^ THE MUMEER DP TICKS ELmPSEH I:: IJUSE' 4E55 4ri4E' 036 455E' E'04F 03m 46E'0 5449 03E 434E 53c'0 04c' 454C 415 04e. 5345 44c' 04m 4953 SMc'O 04E EYTE 04F c:041 4E44 MESSc! TEXT MMH THE CDRRECT TIME IS: ■" 053 c'054 4345 05? c:043 4F5c: 05E 5345 4354 05F c'054 49411 063 453 4'? 5 3 067 3m3 069 E:VTE U 067 CDLDM EQU :i;-3 ♦ ♦ PRDbRMM EEGIMS HERE ♦ 006M EVEM 06M EXMPL EQU :i; U06M 03 00 LIMI - ;iMHIEIT IMTERRUPTS U 6 E c' E n 6 L 1 .1 P I M Y I.. I S ; G E T M I ... I D R K S P M C E 7 c' I J 6 M l: M E L ;>• T ' r ' P E 076 OOOE IiRTM MESSO ? GET TIME DP DRY 078 8116 00 DIM i'HRS ; HDURS 07C 8116 08 DIM i'MIMS ;MIMUTES :=: 8 H 6 i J i J i J 4 HI h i' S- E C: S 5 S E C: D M H 3-: U0:E:4 06 RO OOCR E:L -i'TYPE 8 8 8 n R T R C R L P 5 1 -IS: U E M El ..i LIME efi 6 R EL i' S T I M ; S E T T H E T I M E D P H R Y OOciE 000 URTR MRS 009 06 RO 00 BL i'STCLK ;ZERD THE IMTERVRL TIMER 094 03 0001 LIMI 1 ; RLLDU LEVEL 1 IMTERRUPTS 098 MR IT EQU 'i ■ 098 8C4 IM RO Ou9R 06 RO 00 EL ;>iRIiCLK 09E 11:140 MDV R0-.R5 R Ij 6 R Ij Ij Ij Ij EL i>*G T I M 0R4 00 DRTR HRS ; RERD THE CLDCK 0R6 06 RO OOCR BL ii'TYPE OORR 08C riRTR MESSl ;pRIMT -THE MUMEER DP TICKS...- OORC 81185 DDUT R:5 OORE 06 RO OOCR EL ;i'TYPE 00E8 004P riRTR MESS8 ;PRIMT -RMn THE CDRRECT...-' M0E4 8riR0 0000 DDUT iiiHRS ;pRIMT HDURS OOK: 8CR0 067 DUT i'CDLDh OOEC 8riR0 08 DDUT i'MIMS ;pRIMT MI MUTES OOCO 8CR0 067 DUT i'CDLDM 0C4 8riR0 04 DDUT 5'SECS ;pRIMT SECDMDS 0C8 10E7 -IMP MR IT ♦ ♦ TYPE THE MESSRGE PDIMTED ♦ TD EY THE RETURM RnHRESS OOCR T'r'PE EQU 'i Listing 2 continued on page 300 298 September 1980 © BYTE Publications Inc ;i...iRiT PDR IMPUT ;RERri THE TIMER ; SRVE THE VRLUE Circle 219 on inquiry card. Circle 220 on inquiry card. What TECO* does for minis, TED will do for your micro. Like TECO*, TED is a character-oriented editor that gives you everything you'd expect. Plus, you get many things you wouldn't expect. _ 36 command/text buffers 32-entry push-down stack Sophisticated macros Conditional & iterative command execution Conditional & absolute branching Multiple open files TED and user manual $90 Manual alone $20 Coupon furnished with manuals purchased separately worth $20 towards purchase of TED. You'll also find some elegant enhancements among TED'S 90-plus commands. TED'S compatible with Z-80*-based systems supporting standard CP/M*. We recommend at least 24K bytes RAM. TED's supplied on CP/M*-compatible 8-inch disks. SEND FOR FREE COMMAND SUMMARY jg/small system design PO. BOX 4546 MANCHESTER, NEW HAMPSHIRE 03108 TELEPHONE: 603-432-7929 •TECO® Difilal Equipment Corp.: Z-80* Zilog Inc.: CP/M* Digital Research Inc. CATCH THE S-100INC. BUS! LIST PRICE OUR SPECIAL CASH PRICE Integral Data — "Paper Tiger" 440-G Printer u/lc w/Graphics 1195.00 950.00 S.D. Systems PROM 100 Programmer — Kit 200.00 *171.00 S.D. Systems Z-80 Starter Kit 340.00 *275.00 Goclbout,Econoram X-32 "Unkit" 599.00 512.00 Godbout 3P&S Interfacer "Unkit" 199.00 170.00 * Included free with every S.D, Systems board is an additional 325.00 manufacturer's rebate coupon. Subject to Available Quantities • Prices Quoted Include Cash Discounts. Shipping & Insurance Extra. We carry all major lines such as S.D. Systems, Cromemco, Ithaca Intersystems, North Star, Sanyo, ECT, TEI, Godbout, Thinker Toys, Hazeltine, IMC Fur a special cash price, telephone us. Hours: BuS S-|DD,inC. Mon.-Fri. Address 7 White Place 10 AM 6 p M Clark, N.J. 07066 Interface ....201-382-1318 MAKE YOUR BASIC ilN Developing business applications without keyed file support is like producing a play without the right cast — you can expend needless time and money, and end up giving an inadequate performance. Enter MAGSAM^'' MAGSAM picks up where your BASIC leaves off by providing it with a powerful Keyed File Management System that's quick and easy to use. The result is applications that do exactly what you want them to — instead of only what BASIC allows you to. Supporting Caat MAGSAM's advanced features and capabilities include: • Random, sequential, and generic access by key • Secondary indexing with any number of keys • Key and record deletes with automatic space reclamation • Dynamic file allocation and extension • Complete compatibility with BASIC files • Interactive tutorial program • Dne year update service The versatile MAGSAM file management is now available in two major versions. MAGSAM IV, the new high performance assembler version, is ideal for business applications in which response time is critical. Complete with an interface for CBASIC, MAGSAM IV is 5295. MAGSAM III is the standardversion and is in use worldwide. Written in BASIC, it is available for CBASIC, Microsoft BASIC, or Micropolis BASIC forS145. The MAGSAM manual alone is $25. You're the Star MAGSAM is available immediately —off the shelf. So you can begin saving time and money now while providing your customers and clients with applications that truly meet theirneeds.Sendfora free brochure telling the full story on MAGSAM. or see a demonstration at your computer dealer today. Another Buaineaa Solution from; IVlicRO Applicatioms Group 7300 Caldus Avenue, Van Nuys, CA 91606 nriAB COMING SOON: PRisnn T.M. The Complete Information Management system For Business Another Business Solution From: ruiME MICRO APPLICATIONS GROUP 7300 CALDUS AVENUE VAN NUYS. CA 91406 Circle 221 on inquiry card. Circle 222 on inquiry card. BYTE September 1980 299 Listing 2 continued: ULiCM CiJ3E ijucc PMGE-3 PTC HE UUCC 1107 OOCE 16 01 no 04 5 E OODc' He' c'Cyl 0114 lOFE OODt. MD v' ♦Rll + .PO El EQ _i :i; MTIDM MDVE ♦R0-»-!« Rl jr-iE TYPEc' E ♦ Rll TVPEc' EQU :l; DUT Rl ..iriF- TVPEl ♦ rrr'i,.iv ES:::: 3 c' ;get pd inter ;hET M CHRRMCTER ;hlJLL IS EMD ; PRINT THE CHRRMCTER ;i..inRKSPRCE RRER OOF 6 END 0067 cdldn 08 CRLF ♦ c'ri48 niN ♦ niD ♦c'nsb nnuT ♦ EX IDT ♦ 0U6R EXMPL OORc' GTIN HRS OOOE NESSO UUc'C NESS:l 04F MESSc: OOOc' MINS on 6 MYIOS RO 001 Rl ♦ OOOR R 1 OOOE Rll ♦ OOC Rlc' ♦ 1 j n R 1 3 ♦ OOOE R14 ♦ OOOF R15 ♦ OOOc' R£ ♦ 03 R3 ♦ 1 j 4 R4 00 05 R:5 ♦ 006 R6 ♦ 00 07 R7 ♦ ci R3 ♦ ij'? R9 009C RDCLK ♦ RTC 04 SECS u 03 d STCLK 08C ST IN ♦ 006 ticks; OOCR TYPE OOCC TYPEl one' TYPEc' 098 I.IRIT DUTPUT RERnY" OOOOOEX I nT Ec' 044E4 1 59Ec' Oc'8E4848E3R4nE4n3RE E4n4c'E455c'Ec' 04FE46c' 0E5449E434EE E Oc' 0E4 1 4EE44c' 0E5448E45c' 0E434FE E c' LI I j LI E LI 3 LI Li E ij ij E Li c' E C Ii 6 E Li 6 R i C 04E 06R OC OCRC 08 E 06 R OE Oi! E OEC 1 4 OE 06 R OE OC OE 06 R OC R OR 08E0n ORE OEE 0R45E4E54E455c'Ec' 054E494nE45c' 0E4F467F OFEF 5353Ec'9c' 0E3F OE OE 0RE5448E45c' 0E4E557F 1 78F 53c' 0E454CE4 15 0E5345E44c' 0E4953E3Rc' 07F 1 RCF 5c'5c'E4543E54c'0E5449E4n45Ec'049E533R7FlE9F IS R IS E E c' Ii 6 Li iS iJ E c' Ii 6 Li iS iJ Li Li c' E c' Ii 6 Li 7 F 1 Ii 1 F E Ij 6 R E E iJ 3 iJ iJ E iJ iJ iJ 1 E c' iS 4 iJ E V 6 R iJ 7 F c' iJ c' F C R C c! C E c* n 8 5 E 6 R C C R C 4 F E c' E R 7 F 1 8 C F Listing 2 continued on page 302 HEWLETT-PACKARD'S Calculators at Discount Prices HP-41C Card Reader {4K) Printer f^lCJ THE WAND MfCJ -67 -97 -34C -38C -33C -38E -37E -33E -32E -31E 2621A Terminal HP-85 Personal Compu tei Reg ^3250 /SqIb $2895 HEWLETT PACKARD FARNSWORTH PRiCE »259.CXD M93.00 *346.00 M25.CXD ^318.75 '637.50 M35,CXD M35.00 '99.00 M02.00 '63.75 '76.50 '59.50 '42.50 1395.00 -ADD SHIPPING CHARGE5- - Illinois Residents add 5.25% Soles Tox VISA-MASTER CHARGE-CASHIER CHECK Personal Check OK - Allow 10 days for bonk cleoronce. FARNSWORTH COAAPUTER CENTER 1891 N. Farnsftoiih Ave. (Immediately S. of EW Tollway) Aurora, IL (312) 851-3888 WEEKDAYS 10-8; SAT. 10-5 TRS-8Q* PROGRAMS 32K 2 Disk Drive Min WORD WIZARD I $19.95 Full upper and lower case characterization. Up to 3 pages ol text in memory at a time. Store up to 30 pages of text per diskette. Load, Save, Prinl-out (single or multi-copies) Insert- Delete lines, char- acters, or blocks of text. Block Move Delete Copy lines. Typesetting and variable length page. Type in the text sloppy, clean it up on the screen and print out a perfect copy. MATRIX MANIPULATOR $19.95 All information can be manipulated by columns and rows; adding, subtracting, multiplying and dividing columns by other columns and putting the results in a third column with statistical analysis. BUILDER JOB COST $29.95 Complete job cost analysis package for home builder. 189 user- defined cost categories. Automatic invoice control to actual cost of the home under construction. User input for estimated costs of home. Computer generated cost-to-cost comparisons. Up to 47 homes under construction per data diskette. WORD WIZARD II $29.95 48 K updated version of Word Wizard I. 26 user-defined keys to speed typing chores. Word oriented with automatic wrap around capabilities. Variable printout formatting. £«sy to use. WORD WIZARD I & MAIL LIST COMBINATION $29.95 Word Wizard I as above with 500 mail listings per diskette. Com- puter personalizes letters to selected recipients of letters, forms, etc. using variable select codes. Please allow 2-4 weeks for delivery on Disks only Send $1.00 for full catalog of Hardware & Software Computer Programming Unlimited 6712 Langston Drive Austin, Texas 78723 (512) 928-2626 MasterCard and VISA Accepted *TRS-80 is a Registered Trademark of Tandy Corp. 300 September 1980 © BYTE Publications Inc Circle 223 on inquiry card. Circle 125 on inquiry card. Circle 224 on inquiry card. Circle 225 on inquiry card. 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Model 80 Model 130 Model 129 BYTE September 1980 303 D»i*^l' I8W8 Microcomputers and Physiological Simulation James E Randall Addison-Wesley Reading MA, 1980 234 pages, hardcover $14.50 The observation of living systems is often a complex and difficult task; for those amateur or professional scientists who spend their time investigating the life signs and physiological responses of man and other animals, the use of laboratory computers in the data-gathering phase of their research has become a necessity. In most cases, the invasion of computers into the laboratory environment started with the advent of minicomputers such as the LINC (Laboratory Instru- ment Computer) and later, the Digital Equipment Cor- poration PDP-12. The relatively low-cost and single-user nature of these systems made them especial- ly attractive to the scientist willing to learn computer science. A typical installa- tion would be optimized for data acquisition and format- ting, and sophisticated data analysis, simulation, and modeling would generally be done on large, centralized mainframes such as the IBM 360-91. Time on these large machines was not cheap, and the budgets required to support extensive simulation studies were often pro- hibitive. For these reasons. the study of biological systems by simulation has tended to be restricted and specialized in nature. With the arrival of microprocessor hardware and software systems at much lower cost than minicomputers, and with the development of special- purpose, high-speed arithmetic-processing units, creative and generalized simulation studies may now be performed with a rather modest expenditure of money; of course, inexpen- sive computing tools do not necessarily reduce the total cost of developing the cor- rect system for a particular application. Here is where Dr Randall's book is in- valuable: the background information on micro- processors, combined with specific examples of biological data simulated with various hardware and software configurations, should allow any life-science experimenter to progress rapidly from the initial idea to a working simulation model. The first chapters of the book describe the basic realities of the micro- computer world in a clear and comprehensive fashion; the various evolutionary trends in hardware and soft- ware design which gave rise to some of the more popular present-day microprocessor systems are explained in a cogent and enlightening manner that should orient RACET SORTS — RACET UTILITIES — RACET compuUs - RACET SORTS — RACET UTILITIES — RACET computes - RACET SORTS — RACET UTILITIES — RACET compul«« - FROM RACET COMPUTES- THE LEADER IN UTILITY SOFTWARE FOR TRS* COMPUTERS ■ INFINITE BASIC $49.95 (Mod I Tape or Disk) Extends Level II BASIC with complete MATRIX functions and 50 more string functions. Includes RACET machine language sorts! Sort 1000 elements in 9 seconds! 1 Select only functions you want to optimize memory usage. INFINITE BUSINESS$29.95(Requires Infinite BASIC) Complete printer pagination controls - auto headers, footers, page numbers. Packed decimal arithmetic - 127 digit accuracy + , -, *, /. Binary search of sorted and unsorted arrays. Hash codes. COMPROC $19.95 (Mod I - Disk only) Command Processor. Auto your disk to perform any sequence of instructions that you can give from the keyboard. DIR, FREE, pause, wait for user input, BASIC, No. of FILES and MEM SIZE, RUN program, respond to input statements, BREAK, return to DOS, etc. Includes lowercase driver software, debounce and screenprint! GSF $24.95 Mod I, $50.00 Mod II. (Mod I Tape or Disk - Specify Memory Size) Generalized Subroutine Facilities. The STANDARD against which 'all other sorts are compared! Machine language - fast and powerful! Multi-key multi-variable and multi-key character string. Zero and move arrays. Mod II includes USR PEEKS and POKES. Includes sample programs. DOSORT $34.95 (Mod I Min 32K 2-drive system. Specify Memory Size) Sequential file disk sort merge. Includes GSF. DSM $75.00 Mod I, $150.00 Mod II. (Mod I Min 32K 2-drive system. Modll64K1-drive) ! Disk Sort/Merge for RANDOM files. All machine language \ stand-alone package for 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 I/O ' times make this the fastest Disk Sort/Merge available on Mod I I or Mod II. UTILITY PACKAGE $150.00 (Mod II 64K) Important enhancements to the Mod II. The file recovery capa- bilities alone will pay for the package in even one application! Fully documented in 124 page manual! XHIT, XGAT, XCOPY and SUPERZAP are used to reconstruct or recover data from bad diskettes! XCOPY provides multi-file copies, 'wild-card' mask select, absolute sector mode and other features. SUPERZAP allows examine/change any sector on diskette include track-0, and absolute disk backup/copy with I/O recovery. DCS builds consolidated directories from multiple diskettes into a single display or listing sorted by disk name or file name plus more. Change Disk ID with DISKID. XCREATE preallocates files and sets 'LOF' to end to speed disk accesses. DEBUGII adds single step, trace, subroutine calling, program looping, dynamic disassembly and more!! BASIC CROSS REFERENCE UTILITY $50.00 (Mod II 64K) SEEK and FIND functions for Variables, Line Numbers, Strings, Keywords. 'AIT options available for line numbers and variables. Load from BASIC - Call with 'CTRL'R. Output to screen or printer! DEVELOPMENT PACKAGE $125.00 (Mod II 64K) Includes RACET machine language SUPERZAP, Apparat Dis- assembler, and Model II interface to the Microsoft 'Editor Assembler Plus' software package including uploading services and patches for Disk I/O. Purchase price includes complete copy of Editor Assembler + and documentation for Mod I. Assemble directly into memory, MACRO facility, save all or portions of source to disk, dynamic debug facility (ZBUG), extended editor commands. *TRS-80 is a registered trademark of the Tandv Corporation. DEALER INQUIRIES INVITED .o'^ZTJcl'mlollc, I CHECK, VISA, M/CC. CD. Calif. Residents add 6% Telephone Orders Accepted (714) 637-5016 ^ RACET COMPUTES -^ 702 Palmdale, Orange CA 92665 RACET SORTS — RACET UTILITIES — RACET computes — RACET SORTS — RACET UTILITIES ~ RACET compuUs -~ RACET SORTS — RACET UTILITIES — RACET computtt - 304 September 1980 © BYTE Publications Inc Circle 230 on inquiry card. the neophyte user amidst the growing maze of specifica- tions and performance figures that seem to characterize the technical aspects of microprocessing. Thus, several years of prac- tical experience have been condensed into what will soon be an indispensable reference for anyone con- sidering the mathematical study of physiology. .In addition to people doing research. Microcomputers and Physiological Simula- tion should help those who would like to use in- teractive modeling as a teaching or demonstration device. All too often, an ac- tual experiment may not turn out as expected, or the number of people observing the demonstration is so large that no one learns very much. Given these cir- cumstances, a simulation ap- proach for showing the dynamic realities of various physiological functions is both a clever and necessary approach. For example, in the study of cardiac output and central arterial pressure, a student could make a number of "experimental" manipulations of the cir- culatory system which would, on one hand, help to clarify what really goes on in an intact organism, but which, on the other hand, would be difficult to do within the confines of an ex- perimental preparation. In addition, the time required to load a software model of the heart is much less than that needed to set up a live ex- periment (and, of course, the overall cost of simula- tion is likely to be much less than the real thing). So, given the desire to provide better instruction and reduce the time and money needed to give students first-hand experience in physiology, a teacher in the life sciences should consider carefully the interesting and useful tech- niques developed in this book. Several of the examples in this book are extensions of topics that have been the subjects of articles in BYTE; the electrocardiogram (ECG) receives considerable atten- Circle 231 on inquiry card. tion, as does the nature of the neuronal axon potential and membrane conductances following various stimula- tion examples. In addition, the section on digital filter- ing and waveform distortion is relevant to a wide range of engineering and computer-science applica- tions outside the life sciences. If you already have an Apple II, an S-100-based system, or a TRS-80 system, several BASIC language pro- grams are provided so that you can get up and running immediately; acquisition of the appropriate arithmetic- processing option for your microprocessor will allow you to run more sophisticated and more dynamic simulation studies in a reasonable amount of time. In a larger context. Microcomputers and Physiological Simulation is one more contribution to the field of personal, interac- tive microprocessor-based teaching tools which in specific circumstances offer numerous advantages over conventional methods; the creativity and breadth of in- vestigation allowed by flex- ible and well-conceived soft- ware and hardware systems are in many ways much greater, and certainly achieved with less effort, than our present experimen- tal and pedagogical methods support. Of course, for undergraduate or graduate education and research, having a group of students organize and implement one of the simulations described THE NATIONS LEADER IN AFFORDABLE PRINTERS $749 its available series of new printers designed specifically for the computer market, the MODEL 88T DOT MATRIX PRih ualitv construction and attractive stvlina with caoa lenerallv as jard with a dual tractor 'pressure-roll paper ■eed system and a serial' para ii el interface. The tractor paper Bed system provides the precision required to handle multi copy 'anfold forms, ranging in width from 1 inch to 9.5 inches. The ^ed con be u >bon cartrh Ding. The n or 132 column formatting ^ and lower case charac-^K ters per second. Write ^R^ specifications, pricing i^^^ l^WMHi MICRO PERIPHERALS, INC. 2099 WEST 2200 SOUTH. SALT LAKE CITY, UTAH 84119,. (801) 973-6053 . in this text will not only provide them with an in- teresting tool within their specific field of study, but will also allow them to know in some depth the basics of the microprocessor environment which has become an essential substrate of almost all avenues of scientific and laboratory undertaking. Judging by the possibilities offered in Dr Randall's pre- sent work, the contribution of the microprocessor to laboratory science and technical education will be enormous. Comprehensive guides of this sort serve to allow everyone easy access to a much more evolved set of teaching and experimental tools than has been available before. ■ Nicholas Bedworth Microtex 45 Trowbridge St Cambridge MA 02138 Microcomputer- Analog Converter Software and Hardware Interfacing Titus, Titus, Rony, and Larsen Blacksburg Continuing Education Series Howard W Sams, 1978 286 pages, softcover $9.50 Microcomputer- Analog Converter Software and Hardware Interfacing is a textbook intended for either class use or self -study. It includes learning goals for each chapter, a chapter of experiments, and a large number of hardware and Gondor COIVH=»UTEn CORPORATIOISJ Our Newest Data Base Management System Introducing CONDOR SERIES 20/DBMS, the relational data base management system for users who want power- ful performance at reasonable prices. 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All software in the book is for the 8080 microprocessor; conversion to other 8-bit microprocessors would range from trivial to moderately difficult. The topics covered are: analog-to-digital (A/D) and digital-to-analog (D/A) con- version, interfacing digital panel meters, sample-and- hold and multiplexer cir- cuits, and miscellaneous conversion techniques. Appendices include data sheets and applications notes for a wide range of D/A and A/D devices ranging in cost from a few dollars to a few hundred dollars. The reader of the book is assumed to be familiar with analog circuitry, with digital circuitry, and with 8080 pro- gramming. The level of familiarity required for analog devices is about the same as any radio amateur above the Novice class would have. The digital and computer familiarity are at about the same level; anyone who knows what a three-state buffer is and what the difference is be- tween polled and interrupt- driven I/O (input/output) should have no trouble with the text. Both polled and interrupt-driven systems are discussed, by the way, along with point graphics and measurement systems. All in all, this is a good introduction to digital-to- analog interfacing, and a good reference book. The utility as the latter would be increased if there were a good descriptive index of the devices discussed. As with many of the books in this series, there are no blank pages in front or at the back for notes; most readers will probably want several pages of notes, so this is irritating. ■ John A Lehman 716 Hutchins §2 Ann Arbor MI 48103 Engineer's Notebook: A Handbook of Integrated Circuit Applications Forrest M Mims III Radio Shack Technical Publications 306 September 1980 © BYTE Publications Inc Circle 232 on inquiry card. 128 pages, softcover $1.99 Engineer's Notebook is a collection of hundreds of simple circuits using in- tegrated circuits, each one neatly hand-drawn and labeled, with all of the details (resistor and capacitor values, transistor numbers, etc) filled in. The devices used are primarily TTL (transistor-transistor logic), CMOS (complemen- tary metal-oxide semicon- ductor), and linear function circuits. As a programmer, I keep a file of useful subroutines for each machine and language with which I work. As the file grows, program- ming gets easier because more chunks of new pro- grams come straight out of the file. Engineer's Notebook is the start of my circuit file. Since I am a novice to electronics, I simply cannot say whether an experienced circuit designer will find this collection useful. I tend to doubt it; the book is not written for him. For beginners, however, the circuits are a real help. Not necessarily because they will fit right in- to the next project you build, but because of the help they provide in learning how to use integrated cir- cuits. After a very brief (four- page) introduction to basic electronics (where you are told what resistors, capac- itors, and semiconductors are for), the book launches into CMOS circuits. In about forty pages it presents various circuits, starting with the use of simple gates and moving through switches and decoders, flip- flops and counters, memory devices, and a variety of music- and noise-generating devices including the SN76488N complex sound generator. The TTL section covers simple gate circuits (including a couple of very informative pages on the use of Schmitt triggers), oscillators, selectors and decoders, then counters and dividers. The linear circuits include pages and pages of op-amp applications, LED (light-emitting diode) bar displays, tone decoders, and uses for voltage-controlled oscillators. If you do not know much about electronics and if you want to learn how to use in- tegrated circuits, I suggest you buy one of Don Lan- caster's "cookbooks" (or some other introductory text), and Engineer's Notebook. Use it as a workbook for the text; think of the circuits as answers to questions the text did not pose. Go through them using the text and figure out why they work. Answer the question: Why use this value resistor (capacitor, transistor)? Before very long, you will know what you need to know. I bought the book primarily to learn about TTL. However, because of the variety of circuits presented, I find myself more interested in CMOS and somewhat intrigued by linear circuits. I'm studying all three now. The book is well worth its two-dollar price no matter what use you make of it. ■ Richard Fritzson 25 Callodine Ave Amherst NY 14226 Waiting On Delivery of ADECLA120? i\ Avoid the hassle by upgrading your LA36 for 1200 baud operation with a DS120 Terminal Controller. The Datasouth DS120 gives your DECwriter® II the high speed printing and versatile performance features of the DECwriter® III at only a fraction of the cost. The DS120 is a plug compatible replacement for your LA36 logic board which can be installed in minutes. 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"""^ — ^-' -•->■— --^ •— DATASOUTH COMPUTER CORPORATION 4740 Dwight Evans Road • Charlolle, North Carolina 28210 • 704/523-8500 Circle 233 on inquiry card. September 1980 © BYTE Publications Inc 307 Circle 234 on inquiry card. _^^^s*--^^Mv-^ pC^nce FDIL11/D Dual Density k Floppy Disk ^ Interface , for the i\ LSI-11, ! LSI-11/23 |i«MTf^^ For users demanding the best in reliable extended-density data storage FAST DMA Data Transfer •Single, Double Side • IBM 2D/DEC RX01 Media Compatible • 5.25" or 8" Drives • OEM Discounts Available — Contact Tom Birchell. Peritek corporation 3014 Lakeshore Avenue Oakland, CA 94610 (415) 465-9000 Computer Technology Division HEATH KIT® connputer products and Zenith Data Systenis get even better when you subscribe to Buss: The Independent Newsletter of Heath Co. Computers . Buss spreads the latest news of compatible hardware and software from many vendors. The newsletter is not affiliated with any of these and does not depend on income from ads. So Buss has to please only its subscribers— over 2900 of them. Readers^ candid reports of their discoveries save other subscribers headaches— and money. Innovations published in Buss have included hardware modifications and software fixes. And, since it is not a company-controlled publication, Buss can deal with both the weaknesses and strengths of Heath Co. Computer products. Buss is a proven newsletter that keeps getting better— it^s been published since April 1977. If you subscribe this month you^ll receive a free directory of over 50 suppliers of hardware and software for Heathkit® computers and Zenith Data Systems. You have the choice of starting your Buss subscription with the latest issue or available back issues (about 14). All this information will be mailed first class (by air mail overseas). Full refund guaranteed if you^re not satisfied. Payment must be in U.S. dollars payable on a U.S. bank or by Master Charge or Visa. Issues: 12 18 24 U.S. & Canada $17.98 $24.75 $29.95 Overseas 25.00 30.00 35.00 Buss, 325-B Pennsylvania Ave., S.E., Washington, DC 20003 Beck Reviews Microcomputer Inter- facing with the 8255 PPI Chip Paul F Goldsbrough and Peter R Rony Blacksburg Continuing Education Series Howard W Sams. 1979 224 pages, softcover $8.95 Those who remember the integrated circuits available a year or two ago may wonder how an entire book could be devoted to a single nonmicroprocessor device. The traditional documenta- tion for such a component is "U25 on the System Monitor Board is a Motorola or equivalent 6820 PIA that contains two parallel I/O ports. ...In order to use it however, it must be set up with the proper software" {TDL System Monitor Board Manual). The 217 pages in this book are devoted to showing how the software and hardware for the Intel 8255 PPI (programmable peripheral interface) are set up. The general description (although not the details) is applicable to similar devices such as the above-mentioned 6820 (now 6821) or the Texas Instruments 6011. The 8255 is a parallel in- terface device which allows software configuration of up to twenty-four I/O (in- put/output) lines. It has three basic modes: simple, handshaking I/O, and bidirectional. Up to three different ports may be used (depending on the mode), for input, output, or both. All of this makes the 8255 very flexible; it also makes it complicated. The book discusses I/O schemes in general, and each of the 8255 modes in par- ticular. Experiments are given for both port- and memory-mapped I/O. All hardware and software illustrated are for an 8080-based system, but the effort required to translate to another microprocessor is minor. Both polled-device 308 September 1980 © BYTE Publications Inc Circle 235 on inquiry card. and interrupt-driven I/O are treated, and the book ends with an excellent discussion of the hardware and soft- ware requirements for master/slave processors. This section alone is worth the price of the book. There are, as usual, a few minor faults. On page 63, the diagram of the hex in- verter is not labeled; it is a 74xx04. Numbers in the book are sometimes given in octal and sometimes in decimal radix; unfortunately the author often neglects to mention which base he is using. I suppose ideally he ought to give everything in octal, decimal, and hexa- decimal, but this conve- nience is probably not need- ed by the relatively sophisticated audience at whom this book is aimed. Personally, I find it hard to read an assembler output such as that in the text which runs the op codes and the operands together. PUSH PSW is much easier to read then PUSHPSW. Finally, I would like a bookwide index of the ex- periments; it would make the book more useful as a reference. But all of this is quib- bling; the book is more than worth the price if you fall into one of three groups of readers. The first group is made up of people who have an elementary knowledge of digital logic (perhaps gained from some of the other Blacksburg books) and who want to learn how to use program- mable interfaces in general and the 8255 in particular. The second group is made up of those who would like a more readable reference to the 8255 than is provided by the data sheet, and who want to see sample hard- ware and software inter- faces. Last, anyone putting together multiple-processor systems would do well to look at the last section of the book for a quick and dirty, but fairly simple, way to do it. Let's see, how many channels should I put on my Z80...7B John A Lehman 716 Hutchins #2 Ann Arbor MI 48103 Circle 236 on inquiry card. NOBODY CAN MATCH OUR DOLLAR/QUALITY RATIO! MS-204 PRINTER INTRODUCTORY PRICE: CABLE: $34.50 Compatible with TRS-80, Apple, Pet or any other Centronics-type system Features • 132/80 Columns, 63 LPM, Bi-Directional, Nominal Thruput • 100% Heavy Duty Cycle- High Reliability, 100 Million Character Print Head Life • Sprocket Feed; Variable Forms Width, 2.5" - 9.5" • Double Width Characters: 40,66 Characters per line • 9 X 7 Dot Matrix Character Font • 6-Channel Electronic Vertical Format Unit • Documentation Included Ask about our 8-inch Drives & Software M ATCHLESS YSTEMS 18444S. Broadway Gardena, CA 90248 (213) 327-1010 ® 1980 Matchless Systems & MarketPlan ATTENTION GOVERNMENT D P USERS AND PURCHASERS We represent many fine micro products and manufacturers on the GSA Schedule, including Apple^ Cromemco^ North Star and Vector Graphic 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. 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 Or Call (301) 268-5801 Career Opportunities Available *An Equal Opportunity Employer Circle 237 on inquiry card. September 1980 © BYTE Publications Inc 309 Book Reviews Thrice Upon a Time James P Hogan Ballantine Books, New York NY, 1980 311 pages, soft cover $2.25 Technical books and jour- nals are useful for reference facts. Magazine articles and "construction" books supply the latest in the microcom- puting art to sharpen our faculties. But these all ad- dress the issue of "how/' and nourish the intellect with data. Books such as James P Hogan's latest novel. Thrice Upon a Time, answer a far more primal need. When the soul is anguished by a floppy disk's stubborn recalcitrance; when the heart is discouraged by that elusive last bug in the sorting routine; when the mind is depressed by the manufacturer's twelfth postponement of his ship- ping date, the solace from this book's visions is a soothing balm that carries one through to try again tomorrow. To be sure, Mr Hogan's intricate plot far transcends mere home computing. In his story, which is con- cerned with some natural disasters and some achievements of mankind, he intertwines causes and effects so that each nourishes the other in an ex- citing race to enjoy the benefits of achievement without having to bear the extreme price the conse- quences of the advances seem to engender. Exploring this theme, plus presenting it in a bolero of variations, is a most complex plot concer- ning a time communications machine. As distinct from the mysteriously operating transporting telephone booths of the H G Wells or Dr WHO variety, Hogan presents a rather well- documented, even plausible, invention that takes advan- tage of the Tau wave effect. Now I am sure that Tau waves are not familiar phenomena to many readers. Mr Hogan also is cognizant of this deficiency in the physics background of most of us, and so he presents an explanation of this effect, its discovery and usefulness, with such clarity and vividness that one would no more deny Tau wave existence than one would deny gravity, black holes, or positronic brains. Though I leave the details to Mr Hogan's characters, suf- fice it for the moment that muLTi-TeRminnL comPUTeRs nttcntion COmPUT€R D€nL€RS! THE NEW IBC SYSTEM 40 OFFERS MULTI-USER PERFORMANCE AT SINGLE-USER PRICES. Up to 6 CRT/printers can operate independently and simultaneously. 64K to 128K BYTE memory. 2-24 M BYTE disk storage. Multi-user wordprocessing concur rent with data processing. The IBC System 40 was designed from the ground up to be a true multi-user, multi-tasking computer, and at prices below those of single-user systems. For pricing and complete information on IBC dealerships contact Hntegrated Business Computers 22010 S. Wilmington Ave., Suite306, Carson, CA 90745 (213) 518-4245 Sir Charles has invented a means to send messages back in time. Now imagine, if you will, that the world is faced with a problem; a big one. Say we notice by June, when we are already steeped to our knees in the problem (figuratively), that if we had known to do some "X" back in January, most of this trouble would be nonex- istent. Say we do send a warning back. Would that mean that we are no longer troubled, or that we no longer are, at all? Then why, or who, would have sent the message? Yes, this paradox has been explored before. But a marvelous craftsman and clear thinker such as James Hogan deserves his plat- form, and he exploits it with the quintessential detail and plausibility so reminiscent of the John W Campbell era. So, you may concede, it's a gripping story. But where does my Altair or Apple come in? The answer is on just about every page. It is assumed in the story that at that time, 30 years from now, most people have a working knowledge of high- level languages. The elderly Sir Charles has a small com- puter in his home, and it is not a remarkable occur- rence. When he needs extra computing power or com- mon data, he doesn't think twice about linking into the national data grid, which offers such services, as any other utility would offer its resources to home users to- day. What is so all-fired ex- citing about this story is that Sir Charles, with a setup not too different from what is available right now to us in our computer rooms, has sat down and used that com- puter to make a time machine. Sure he has access to a Tau wave generator, which most of us still would have trouble acquiring. But if Sir Charles can move such mountains with his setup. 310 September 1980 © BYTE Publications Inc Circle 238 on inquiry card. surely we can at least move a few molehills with ours. The book is top-notch. As a story, it's exciting and in- volving. As an inspiration, well I don't want to write any longer. My microcom- puter awaits. Jay P Lucas 3409 Saylor PI Alexandria VA 22304 Noise Reduction Tech- niques in Electronic Systems Henry W Ott John Wiley & Sons New York NY, 1976 294 pages, hardcover $24.50 Although frequently unrecognized, electrical noise is a serious problem in the microcomputing en- vironment. The home microcomputer is a recog- nized source of elec- tromagnetic interference (EMI) or radio-frequency in- terference (RFI). The sound effects of computer games produced on a nearby radio are the mark of clever pro- gramming and poor elec- tromagnetic shielding. Fur- ther, many prototype or even final versions of digital and analog projects fail completely or suffer occa- sional untraceable glitches because of improper atten- tion to noise sources. Addi- tionally, the rush to marry the continuous, frequently low-level, analog signals to fast-switching, noisy digital microcomputers promises many tremendous EMI problems. Intolerably, from tens to hundreds of millivolts of digital noise may appear in analog signals that never exceed 10 V and are frequently in the 0.1 V to 1 V range. The above problems can be solved by the application of information about noise — preferably done systematically in the initial design rather than as a patchwork correction after the fact. Ott's extremely well-written book contains this information and is one of the finest books on elec- trical noise, its sources, propagation, reception, and suppression. This book is an outgrowth of lectures at Bell Laboratories, and is directed at a technician-level two- year college program. Chapter 1 is a lucid discussion of noise sources, their coupling into your system, and a summary of the elimination methods: shielding, grounding, balancing, filtering, isola- tion, separation and orienta- tion, circuit impedance con- trol, cable design, and cancellation. The remainder of the book expands on these points. Chapter 2 discusses the theory of shielding conduc- tors, and why it does not always work. The distinc- tion between capacitive and inductive coupling is care- fully made. Grounding schemes for cables are clearly shown along with their relative merits. Chapter 3 discusses pro- cedures for minimizing ground loops, low-frequency and high-frequency ground- ing (they are different), and grounding shields properly. Especially important, and carefully treated, is the elimination of ground loops. Chapter 4, "Other Noise Reduction Techniques," discusses balancing, power- supply decoupling, the much misunderstood transmission impedance of a power distribution system and its effect on system perfor- mance, high-frequency decoupling filters and digital circuits. Chapter 5, "Passive Components," shows how these poorly appreciated components can dramat- ically affect system perfor- mance. Chapter 6 is "Shielding Effectiveness of Metallic Shields" and is full of pleas- ant and unpleasant surprises about shielding properly. Ott discusses in detail how to really prevent EMI generation or reception. Chapter 7 is on "Contact Protection" in switches and relays. This unlikely sound- ing chapter in a book on noise suppression is quite logical. Switches and relays are notorious sources of EMI, and contact protectors yield improved life and per- formance and also have the beneficial effect of reducing EMI. Chapters 8 and 9 are about intrinsic noise sources and active-device noise. These two chapters are of greatest value for low-level analog measurements rather than for microcomputer uses. This book is not easy to read, as it assumes familiar- ity with DC circuit theory as well as with capacitors, in- ductors, and the complex impedance treatment of AC circuits. This level of exper- tise is not required for the book to be exceedingly valuable, however. It is clearly written with a lot of examples and good problems with their solutions. Like a good novel, it was difficult for me to put this book down. The physical Hard Disk Made Easy Now you can move up to hard disk trouble free. Just select the XCOMP X/S series controller for your disk drive: SMD, Cartridge drive, 8 inch disk bus or Shugart® SA1000. Our complete package, including first class support software, will get you up and run- ning fast. And the cost will be less than you would expect. We specialize in getting OEM's into hard disk systems. Our customers include the most successful companies in the microcomputer world. Move up to hard disk the easy way. Call XCOMP— we'll get you going with hard disk right now. XCOMP INCORPORATED 9915A Businesspark Avenue San Diego, CA 92131 (714)271-8730 Circle 239 on inquiry card. September 1980 © BYTE Publications Inc 311 significance of an equation is discussed clearly and at length; abundant graphs demonstrate concepts and provide valuable later reference. Finally, Ott is ex- ceedingly practical. He has obviously spent long hours up to his elbows in wire and soldering irons tracing down and eliminating noise bugs, and he tells you his secrets. The book is full of useful and interesting facts. For example, the switching of a single transistor-transistor logic (TTL) gate connected to a power supply through 10 inches of 22 gauge wire causes the ground connec- tion of the integrated circuit to jump by 0.4 V. The syn- chronous switching of five gates could cause the ground to rise to 2 V! Since 2 V is the logic threshold for transistor-transistor logic, proper operation would be unlikely. This particular problem, a common cause of malfunctions in bread- boarded circuits, is partially solved by bypass capacitors. Do you know how a power-distribution bus strip works? Why a double-sided printed-circuit board can give far better performance than point-to-point wiring, even with very heavy wire, or even a single-sided printed-circuit board? How much ground area do you need on a printed-circuit board? Do you know what a ferrite bead is, and how it suppresses noise? Do you know what the best type of filter capacitor for filtering an input line is? (The answer is not ceramic disc.) Why is copper a better magnetic shield than steel at high fre- quencies? How do you seal a cabinet door to EMI? Why, in a cabinet, does a series of ventilating holes with a total area of 1 square inch leak far less EMI than a single crack in the door with an area of 0.1 square inches? Ott explains this plus much more. The book has a few short- comings. The author does not always tie separately presented concepts together, and the reader must perform this synthesis. I would also like to have seen more infor- mation on power-line EMI filters. The book was not written with computers in mind so there are no explicit references to them. The in- formation on digital circuits is very brief. Counterbalanc- ing these problems is the fact that the book does not deal with obsolete technologies, but handles fundamental principles which will always be a proper starting point for at- tacking a new area. In summary, this is an ex- cellent book. It should be read by every serious analog/digital designer. A careful reading and applica- tion of Ott's principles will save great pain, hours of labor, money, and in some cases even entire projects. ■ J N Demas Department of Chemistry University of Virginia Charlottesville VA 22901 A THE AQUARIAN BY MARILYN CONSPIRACY FERGUSON great shuddering, ir revocable shift is over- taking us. It is not a new political, religious or economic system. It is a new mind, a turn-about BITS, Inc. Books to erase the Impossible P.O. Box 42B Peterborough, N.H. 03458 in consciousness in critical numbers of in- dividuals, a network powerful enough to bring about radical change in our culture. Please send . . copies at $15.00 each. Postage and handling included. SHIPP6D DIR6CT FROM PUBUSH6R Please check: D VISfi D MasterCharge D Check or mone^ order Call 24 hours a day: 800-258-5477 N.H. residents 924-3355 IBO90 BYTE's eits Tracking Down the Modenn Filters Since my article "An Answer/Originate Modem" was published in the June 1980 BYTE (page 24), I have found that the company which makes the CH1262 and CH1267 filters has moved. The current address and telephone number are: Cermetek Microelectronics 1308 Borregas Ave Sunnyvale CA 94086 (408) 734-8150 The filters are available as "miniModem" building blocks from this firm. Ronald G Parsons 9001 Laurel Grove Dr Austin TX 78758 The Source and Tynn- share Sign Operations Agreennent Source Telecomputing Corporation and Tymshare Inc have entered into a development and pilot operation agreement under which Tymshare, a com- puter service company, will provide a variety of facilities and services to increase the user capacity of The Source, an information utility. Tym- share's subsidiary. Tymnet Inc, which operates the TYMNET public packet- communications network serving 200 cities, will be utilized in The Source's ex- pansion program. The number of Source users, now approaching 5000, has increased beyond the system's present capabilities. Utilizing TYMNET's equip- ment and expertise will better serve existing users and permit The Source to accommodate thousands more. Through The Source, owners of home computers, computer terminals, and word-processing equipment are able to access a variety 312 September 1980 © BYTE Publications Inc Circle 240 on inquiry card. of data bases and programs by telephone connection to computers of The Source network. For details, contact The Source, Source Telecomputing Corporation, 1616 Anderson Rd, McLean VA 22102, (703) 821-6660. Heath Offers Source Code to Its Customers Heath Company, Dept 350-390, Benton Harbor MI 49022, (616) 982-3210, is offering to its microcom- puter customers source code for the company's internally developed system software and hardware. Source code to be released include those for Heath's cassette assembler, debugger, editor, and BASIC, and the source code for HDOS, Heath's disk operating system. Also being offered are the firm- ware for the H-17 and H-89 disk controllers and the firmware for the H-19 video terminal. The source code listings are $25 each except for HDOS, which is $195. The H-19 code will also in- clude source on a Heath HDOS floppy disk and the character generator ROM (read-only memory) code. HDOS source code is available on floppy disk and includes the disk Assembler, Editor, BASIC, and DBUG, as well as PIP and other utilities. All products remain copyrighted, and even though source code is available, it is not being placed in the public domain. Heath welcomes licensing discussions for HDOS from other manufacturers. Computer Bulletin Board for Radio Amateurs A free access program, called HAMNET, was established by Donald Stoner, W6TNS, and The Peripheral People, POB 524, Mercer Island WA 98040, (206) 232-4505. HAMNET utilizes the extensive MicroNet communications network, which allows ac- cess through almost two hundred local telephone numbers. Checking into HAMNET permits users to post and retrieve messages for help wanted, equipment for sale, network news, schedules, and so on. Other features planned are prop- agation forecasts. Federal Communications Commis- sion (FCC) news, new pro- duct announcements, and more. Public-domain pro- grams are also available. HAMGAB is a ham "fre- quency" for two users to communicate or transfer programs. While the system is primarily oriented towards amateur radio buffs, it is open to all MicroNet Customers. A subscription to MicroNet is $9 and $5 per connect hour. Customers are given a 128 K-byte block for storage of files. Information is available from Personal Computing Division, Com- puServe Inc, 5000 Arlington Centre Blvd, Columbus OH 43220. New TRS-80 Keyboards Radio Shack has an- nounced an important change in its TRS-80 Model I microcomputer. The new keyboard that uses a capacitive-contact system to eliminate the well-known keyboard debounce prob- lem does not have removable key caps, which were on the older TRS-80 models. Any attempt to clean the keyboard by removing the key caps will result in damage to only those TRS-80S that have the new keyboard. TRS-80s with the new keyboard are distinguished by a dull (as opposed to a shiny) finish on the keys and a curved (as opposed to a straight) slope of the keyboard tops when viewed from the side. Educational Software for the Apple The Department of Natural Science at Eastern Kentucky University, Memorial Science 220, Rich- mond KY 40475 (606) 622-3735, has completed a search for educational courseware written for microcomputers. They have compiled a catalog of educa- tional software for the Apple II computer. Schools may obtain a copy of this catalog by writing to Pro- fessor John Wernegreen at the above address. ■ eYTE'seBgs Catching the Khachiyan Bug In Part 1 of "Khachiyan's Algorithm" by Berresford, Rockett, and Stevenson (August 1980 BYTE), a typographical error occurred in an Editor's Note by Gregg Williams (GW) at the bottom of the first column on page 202. The error at the end of line 7 of the italicized paragraph is in the equation t = K/ The correction is t = Kw.m THERE'S ABIG MARKET FOR APPLES IN ROCHEreUER CENTER. n*WM^ We're selling a lot of Apples in the heart of New York City. Our business in Dynabytes and Hewlett-Packards is booming too. The truth is a lot of people are finding Datel's approach to selling micro hardware, software, peripherals and the training and service that go with them just what the doctor ordered. If you find yourself in our neighborhood stop in and look over our selection, and have a chat. We'll show you the right system up front. And if you buy it, we'll stand behind it. clatel STORES OF NEW YORK 1211 Avenue of the Americas, New York, N. Y 10036/(212) 921-0110 Circle 241 on inquiry card. September 1980 © BYTE Publications Inc 313 Circle 242 on inquiry card. TARGET HOST -TARGET HOST ^ TARGET HOST H UJ < k c/5 O X H UJ O < c/) O X H UJ O < i H CO O X UJ o a: < A H o CROSS COMPILE FORTH! CROSS COMPILING IS THE MOST CONVENIENT WAY TO IMPLEMENT AND EXTEND FORTH. NOW YOU CAN CROSS COMPILE AN ENTIRE FORTH SYSTEM WITH ALL FORWARD REFERENCES RESOLVED IN A SINGLE PASS TO PRODUCE AN EXCUTABLE IMAGE IN MEM- ORY OR ON DISK AND A LOAD MAP OF ALL DEFINED SYMBOLS. THE CROSS COMPILER IS WRITTEN IN HIGH LEVEL FORTH INTEREST GROUP (FIG) FORTH. A COMPLETE DESCRIPTION OF EACH WORD IN THE CROSS COMPILER IS GIVEN WITH STEP BY STEP STACK CONTENTS FORTH INTERNALS (NEXT. BUILD. DOES. CREATE. ETC.) ARE ALSO COMPLETLY DE- SCRIBED. A CROSS COMPILABLE VERSION OF THE FIG MODEL 1.0 IS PROVIDED FOR THE 8080 WITH AN ASSEMBLER / DISASSEMBLER THIS MAY BE EASILY CONVERTED TO ANY MACHINE. A DETAILED DE- SCRIPTION IS GIVEN FOR FIRST TIME IMPLEMENTA- TIONS. THE ENTIRE PACKAGE IS AVAILABLE FOR $70. FROM: Nautilis Systems P.O. Box 1098 SantaCruz,CA. 95061 FOR THE SERIOUS FORTH USER H CO O X UJ o < k H c/5 O X H UJ O < CO O X H UJ < O X TARGET HOST •-TARGET HOST*- TARGET HOST IS THERE A GAP IN YOUR LIFE GAP General Accounting Package. Fantastic double entry accounting system with user definable ac- counts. The account numbers are made up of 7 4-digit fields allowing 7 levels of account classifications. With the use of the Operator Report Selector Generator (OSRG), you can generate any type of report you desire, or use report programs in GAP-GL, GAP-AP, and GAP-AR. GAP-GL Includes all basic GAP functions, plus entry of General Ledger transactions, prints General Journal, General Ledger summary and detail. Balance Sheet, Profit and Loss. Price $124.95 GAP-AR Requires GAP-GL to run, allows adding A/R in- voices, printing Sales Journal, detail A/R report, Account Aging, add/update Cash Receipts with register. Cash Receipts Journal, and A/R Billing. Price $99.95 GAP-AP Requires GAP-GL to run, allows adding of A/P invoices, printing Purchase Journal, detail A/P report. Aging of Accounts, Check Writing, Check Printing, Cash Disbursements Journal. Price $99.95 Systeiv requirvmeius ure 32K C f* .\f CP \Us registered trademark of Digital Research PROFESSIONAL DATA SYSTEMS 318 E 18 St. BAKERSFIELD CA. 93305 (805) 323-0891 Technical Fomkr A $5.25 Interface to the BSR X-10 Home Control System Alan R Trimble, Tracon Corporation, 6615 Kentland Ave, Canoga Park CA 91307 The availability and reasonable cost of the BSR X-10 Home Control System, coupled with the ease of inter- facing the system to a home computer, will undoubtedly spawn a revolution in home automation. (See Steve Ciar- cia's article "Computerize a Home," January 1980 BYTE, page 28.) Already I have seen advertisements in BYTE and other computer magazines for interface equipment in the $100 to $200 range, offered by at least three different manufacturers. Eager to get my home under computer control, but not too eager to shell out $114.90 for the S-100 MicroMint system described in Steve's article, I was motivated to implement the system in software. All that is needed is an ultrasonic transducer and a single bit from a parallel output port. The transducer is simply connected directly across the output port line (transistor-transistor logic [TTL] levels are sufficient to drive the capacitive transducer load) while the computer is used to generate the 40 kHz bursts that make up the coded message to be transmitted to the BSR X-10 com- mand module. The output port was easy to come by — I had a spare one — but even a single line from a dedicated port could be used, such as a bit from a parallel printer-interface port, provided that the printer is not strobed when data is output to the port. Finding a 40 kHz ultrasonic trans- ducer did not seem quite as simple. After calling a few local electronic stores, however, I was able to locate one for $5.25 (Calectro catalog number J4-815). All tools in hand, I set out to emulate Steve's command generator in software on my 4 MHz Z80-based S-100-bus system. The calling sequence was set up so that the rou- tine could be called using Cromemco's FORTRAN, but it is a simple matter to modify this as required. At the heart of the program are two subroutines: FORTY, which generates a 40 kHz signal of specific dura- tion, and DLY, which provides a programmable delay. These make careful use of instruction execution times to provide accurate timing. As written, they will work only with Z80/8085 systems running at a basic clock rate of at least 4 MHz. FORTY and DLY are used in subroutines SNDl, SNDO, and TERM, which generate the transmission codes for a logic 1, a logic 0, and the code-termination se- quence, respectively. These, in turn, are utilized by the main routine XMIT, 314 September 1980 © BYTE Publications Inc Circle 243 on inquiry card. Circle 244 on inquiry card. which builds the message to be transmitted from the single-byte code passed as an argument. The code passed is exactly as described in table 1 of Steve's article. Admittedly, the software required to drive the trans- ducer is neither processor nor speed independent, but the concept is simple enough to be used on virtually any system. Listing 1: Tfiis software, called from Cromemco FORTRAN, is used to drive an ultrasonic transducer directly from a parallel output port. Output frequencies and timing are based on the 4 MHz clock rate of the author's Z80 system. 0002 ; XMIT: TKANSHIT COMMAND TO HOME CONTROL SYSTEM 0003 0004 ; PURPOSE: TO GENER/iTE THE SIGNALS REQUIRED TO DRIVE AN ULTriASOWIC 0005 TRANSDUCER TO TRANSMIT COMMANDS TO THE DSR X-10 (01) SEARS 0006 ilOHE CONTROL SYSTEM 0007 0008 ; USAGE CALL XHIT 0009 0010 ; WHERE (IL CONTAINS THE ADDRESS OF THE COMMAND DYTE 0011 0012 COMMAND BYTE (DECIMAL) : 0013 ALL OFF = 1 CKl = 12 CH7 = 10 CU13 = 0014 LIGHTS ON = 3 CH2 = 28 CH8 = 26 Cill4 = 16 0015 ON = 5 CH3 = 4 CH9 = 14 CH15 = 6 0«16 OFF = 7 CH4 = 20 CHIO = 30 CI116 = 24 0017 DIM = 9 CHS = 2 CHll = 6 0018 BRIGHT = 11 CH6 = 18 Clil2 = 22 0019 0020 ENTRY XHIT 0021 0000' F5 0022 XHIT: PUSH AF; SAVE REGISTERS . , 0001' CS 0023 PUSH DC 0002' D5 0024 PUSH DE 0003 E5 0025 PUSH HL 0004 7E 0026 LD A, (HL) ; GET THE CODE WORD 0005 07 0027 RLCA; POSITION THE CODE WORD 0006 07 0028 RLCA 0007 07 0029 RLCA 0008' 2F 0030 CPL 0009 5F 0031 LD E,/^; SAVE Ti!£ COMPLEMENT FOR LATER USE OOOA- 2F 0032 0033 CPL OOOB' CO2F00' 0034 CALL SNDl; TRANSMIT T!IE START BIT OOOE' 1605 0035 LD D,5; SETUP TO TRANSMIT THE NEXT 5 BITS 0010' 07 0036 XLPl: RLCA; SHIFT BIT TO BE TRANSMITTED INTO CARRY 0011 ' DC2?00' 0037 CALL C.SNDl; SEND A ONE If CARRY IS SET 0014' D43D00' 0038 CALL NCSNDO; SEND A ZERO IF CARRY IS CLEAR 0017' 15 0039 DEC D 0018' 20F6 0040 0041 JR NZ.XLPl; LOOP UNTIL 5 BITS HAVE BEEN SEtfr OOIA' 1605 0042 LD D,5; SETUP TO TRANSMIT A.NOTHER 5 BITS OOIC 7B 0043 LD A,E; GET THE COMPLEMENTED DATA OOID' 07 0044 XLP2: RLCA; SHIFT BIT TO BE TRANSM ITTLD INTO CARRY OOlE' DC2F00' 0045 CALL C.ShJDl; SEND A ONE IF CARRY IS S.iT 0021' O43O00' 0046 CALL NCSNDO; SEND A ZERO IF CARRY IS CLEAR 0024' 15 0047 DEC 0025' 20F6 0048 JR NZ,XLP2; LOOP UNTIL 5 BITS HAVE BEEN SENT 0027' CD4B00' 0050 CALL TERM; TRANSMIT THE TERMINATION SEQUENCE 002A' El 0051 POP HL; RESTORE THE REGISTERS 002B' Dl 0052 POP DE 002C' CI 0053 POP DC 002D' Fl 0054 POP AF 002E' C9 0055 RET 0057 ; SNDl: SEND (TRANSMIT) A ONE 0058 002F' F5 0059 SNDl: PUSH AF; SAVE A<.'CiUH 0030' 06AO 0060 LD B , 1 6 ; 4MS 0-» 40K11Z 0032' CD5C00' 0061 CALL FORTY; GENERi^TE 40KHZ BURST 0035' 21D703 0062 LD I!L,03D7H; DELAY FACTOR 0038' CD7100' 0063 CALL DLY; DELAY REMAINING BIT TIME 003B' Fl 0064 POP AF; RESTORE ACCUM 003C' C9 0065 0066 0067 RET 0068 ; SNDO: SEND (TRANSMIT) A ZERO 0069 003D' F5 0070 SNDO: PUSH AF; SAVE ACCUM 003E' 0630 0071 LD B , 4 8 ; 1.2MS OF 40KHZ 0040' CD5C00' 0072 CALL FORTY; GENERATE 40KHZ BURST 0043' 219506 0073 LD IIL,0695H; DELAY FACTOR 0046' CD7100' 0074 CALL DLY; DELAY REMAINING SIT TIME 0049' Fl 0075 POP AF; RESTORE ACCUM 004A' C9 0076 0077 0078 RET 0079 '; TERM: TRANSMIT TERHIN ATION SEQUENCE 0080 004D' 1604 0081 TERM: LD D,4; SEND 4 4HS BURSTS OF 40KHZ 004D' 3EA0 00B2 TLPl: LD A, 160; SETUP FOR 4HS 004F- CD5CD0' 0083 CALL TORTY ; TRANSMIT 40KHZ 0052' 15 0084 DEC D 0053- 20F8 0085 0086 0087 JR NZ.TLPl; LOOP FOR 16MS 0055' 215C17 LD 1IL,175CI!; DELAY FACTOR 0058' CD7100' 0088 CALL D1,Y; DELAY 24MS 005B' C9 0089 RET 0091 ; FORTY GENERATE 40 KHZ 0092 0093 009i ; USAGE l.D B,V/iLUE CALL FORTY 0095 0096 • WHERE B CONTAINS DURATION FACTOR 0097 0098 '; NOTE: DURATION = ( 100 * 3 + 33 ) * 0.25US 0099 ( INCLUDES LD h CALL INSTRUCTION TIMES ) 0100 0101 '; HODIF lED: A, D, C, fi, L 0102 0103 (0000) 0104 DO: EQU 0; OUTPUT DATA FOR ZERO (0004) 0105 Dl: ECU 4; OUTPUT DATA FOR ONE (0018) 0106 PORT: EQU IBH; OUTPUT PORT 0107 0108 005C' 3E04 0109 FORTY: LD A.Dl 005E' D318 0110 OUT (PORT), A; OUTPUT A HIGH 0060' 0E02 0111 LD C,2; DELAY COUN-r 0062' on 0112 FLPl: DEC C 0063' 20FD 0113 JR NZ.FLPl; DELAY BETWEEN OUTPUTS IS 12.6US 0065' 3E00 0115 ' LD A , D ; DATA FOR LOW OUTPUT 0067- D318 0116 OUT (PORT) ,A; OUTPUT THE DATA 0069' OEDO 0117 LD C,0; DELAY 006B' OEOO 0118 LD CO; DELAY 006D' 05 0119 DEC D 006E' 20EC 0120 JR NZ, FORTY; END OF CYCLE 0070' C9 0121 0122 0123 RET 012^1 0125 0126 ,' DLY: PROGRAMMED DELAY ; USAGE LD UL.VALUL 0127 CALL DLY 0128 0129 '; WHERE HL CONTAINS DELAY FACTOR CONTRACT PROGRAMMERS $15 to $30 per Hour Our clients have immediate short-and long-term assignments available for experienced programmers in either field -- mini/mainframe. Paid weekly; full benefits available. • Software Tech. Writers • Software/Hardware Engineers (INTEL 8085) • Programmer/Analyst (COBOL. IBM. or DEC 10) • Systems Programmer (Mini/ Micro Assembly. FORTRAN. & BASIC plus) digital arts group CONTRACT SERVICES For immediate con- sideration, contact: Jim Barry. Suite 101. Nine Bedford Street Burlington. MA 01803 (617) 273-2780 Listiiig 1 continued oti page 316 CP/M SOFTWARE ADAPT 2.00 Runs Croftieftico Sofhvare Under CP/M 1.4 or 2.2 S75 Get Cromemco software to run on your CP/M Version 1.4 or 2.2 system. ADAPT interfaces most of those powerful Cromemco packages to any Z-80 based CP/M system without patching. ADAPT works without changes for any memory size. RATFOR-80 Fast RATFOR Language (RATional FORtran} $95 RATFOR-80 lets you write structured code that translates to Microsoft or Cromemco FORTRAN. TSW's RATFOR-80 (RATional FORtran) pre- compiler runs at more than 1000 statements per minute. Price includes extensive subroutine library. Documentation includes "Software Tools" book by Kernighan and Plauger. (ADAPT and RATFOR packages combined $150) FMT FMT Word Processing Text Formatter for CP/M $75 FMT works with any CP/M editor to give you automatic page headings and footings, page numbering, centering, underscoring, external file merging, and in-line console input. FMT works with any video, CRT, or hardcopy terminal and printer combination. With daisy-wheel printers, FMT provides superscripting, subscripting, and half-line spacing. THE SOFTWARE WORKS 8369 Vickers San Diego, CA 92111 (714) 569-1721 VISA and MaslcrCharge accepted ■ Cl'-M is a (rademark of Digiial Research September 1980 © BYTE Publications Inc 315 Circle 245 on inquiry card. INTRODUCING MICROFLEX 65 Rockwell takes AIM to infinity Expand the capabilities of your AIM with Rockwells new Microflex 65 product line. CompuMart carries single & multiple add on modules made by Rockwell for your Rockwell AIM. Write for CompuMart s complete brochure on Microflex 65. Write CompuMart, 270 Third Street Dept 129 RO. Box 568 Cambridge, Mass. 02139 COMPUMARZ. Zo-SYSTEMS '^ ZOBEX Complete compuler on 3 S-100 boards with 32K RAM for Under $1000.00* Runs M/PMandC/PM 64K RAM 4 MHz No WAIT States IEEE Std. Low power, DMA operation, Bank select in 16K sections Can be disabled in 4K increments ) 1 Z80 CPU 2-4 MHZ IEEE Std. 2 or 4 serial ports, 3 parallel, one 4K EPROM, Vectored interrupts, real time clock. Software controlled baud rates, 1 1 Drives daisy wheel printer directly DISK CONTROLLER 8" and 5" DRIVFS All digital design for stable and reliable performance. No one- shots or analog circuitry. BIOS for 1 1 C/PM available. CARD CAGE and Fan 6 slot shielded motherboard for good cooling and low noise. SEND FO 6 months vvarrt ZsSY 5333 Mission Ce P.O. Box 18 ♦imroducto R FREE INFORMATIONS inly on our boards with normal use STEMS / ZOBEX titer Rd., San Diego, Ca. 92108 47, San Diego, Ca. 92112 714) 447-3997 ry oClcr for limited time only Listi ng 1 coiitimied: 0130 0131 ; NOTEj DELAY = ( 4107*U + 16 L + 67 ) * 0.251JS 0132 ( DELAY INCLUDES LD i CALL INSTRUCTION TIKES ) 0133 0071' 24 0134 DLY: INC H; SETUP FOR DELAY LOOP 0072' 2C 0135 INC L 0073- 2D 0136 DLP: DEC L; MINOR DELAY LOOP 007 4' 20FD 0137 JR NZ.DLP; DELAY THE SPECIFIED COUNTS 0076' 25 0138 DEC H; MAJOR DELAY LOOP 0077 ' 20FA 0139 JR NZ.DLP; DELAY THE SPECIFIED COUNTS 007 9' C9 0140 0141 RET 007A' (0000) 0142 END Error Progr am Length 007A (1 2) CROSS REFERENCE LISTING DO 0104 0115 Dl 0105 0109 DLP 0135 0137 0139 DLY 0134 0063 0074 0088 FLPl 0112 0113 FORTY 0109 0061 0072 0083 0120 PORT 0106 0110 0116 SNDO 0070 003li 0046 SNDl 0059 0034 0037 0045 TERM 0081 0050 TLPl 0082 0085 0020 10022 Steve Ciarcia's Comments My compliments to Alan Trimble on his ingenuity. An ultrasonic transducer tied directly to one line of an output port is a very viable approach. In fact, the first control circuit I designed employed an NE555 timer, used as a tone-burst generator, and an ultrasonic transducer attached as you describe. This additional $0.50 component (the NE555) further reduces the soft- ware overhead while maintaining minimum system cost. When I wrote the article, I made a tough decision. Either I could present a $6 interface designed for use with a computer that has existing outpM ports, a par- ticular system clock rate, and a partictilar processor, or I could make the hardware smarter (and more ex- pensive) and yet usable on virtually any computer. With the first alternative, I would have gotten about 200 letters asking how to design a parallel output port; the second was the better way to proceed under the cir- cumstances. There are often many approaches to the design of an interface. My philosophy is to try to tender the one that has the greatest potential for being implemented by BYTE readers. I'd rather not be remembered for my great theoretical presentations. I depend on intelligent people like Mr Trimble to read between the lines and customize my interfaces to meet their individual system requirements. Regarding the expense of buying the equipment, I am familiar with only the MicroMint unit (the Busy Box). For the purchase price, you get a unit that is assembled and tested; it includes a case, power supply, and instructions; and it comes with the cables required to plug it in and use it. Anyone wishing to build Mr Trimble's design for a control interface can get the 40 kHz transducer (part number MM 1002) for $6 postpaid from: The MicroMint Inc " 917 Midway Woodmere NY 11598 (516) 374-6793 My thanks to Mr Trimble for pointing out this ap- proach to interface design.,.. Steve Ciarcia 316 September 1980 © BYTE Publications Inc Circle 247 on inquiry card. D-G Electronic Developments Co. Introduces NEW Hardware, Firmware, and Software support for the H8. Combined with the already popular DG-80 CPU, our pro- ducts provide an ever increasing line of complimentary support devices to enhance the power and flexibility of the H8 Computer. INTRODUCING: the DG-64D ^ U p to 64K bytes capacity Dynamic RAM Prices: \^ Hardware bank selectable in 8K increments — , ^ _^ ^ ■^^^ ^^ 0^ 1^ Software bank selectable in 16K increments through I/O port W%m^^/^ ^5^?^r OO 1^ On-board bank select/CPU ROM disable port, addressable to ^'^■^ b^^ M m\0\0 any 256 I/O addresses 4fil^ 480 00 1^ Up to 8 boards controllable through one I/O port (allows page ^Oix "rOVaW mode operation) '^71^ 431 00 ^ On-board transparent refresh for 8080 or ZBO microprocessor ■-^^■^ "r J ■ ■ W backed up by asynchronous refresh upon loss of normal prog- 1/1/' 9Q^ A A ram execution ' O"^ 3ISZ.UU i> 4 MHz operation with no wait states required (t\\C -l-l-l OO ;>^ Low power consumption iL/ix ^^^n\3\3 \/^ Assembled, tested, & burned-in— 90 day warranty Documentation only fDG-64D) 1 5.00 STATE OF THE ART CPU FOR THE HEATHH8 DG-80 ZSO'CPU— 249.00 (Assembled & Tested) Documentation only: $25.00 NEW— SUPPORT for the DG-80 the DG-FP8 Monitor/Utility package for use with the DG-80 CPU which provides functions of PAM-8 as well as the following: u^ Z80 monitor features such as display alternate register sets, display index registers, etc. u^ "Shorthand" modes for display of memory contents pointed to by general purpose registers ^ Supports STANDARD CP/M provided by D-G Electronic Develop- ments Co. as well as HDOS i^ Provides firmware support forDG-ADP4, 4MHz hardware the DG-ADP4 Plug-in hardware modification to allow operation of the Heath H17 disk system with the DG-80 at 4 MHz. Requires the use of the DG-FPB firmware package. STANDARD CP/M^Ver. 2.2 16K CHIP SETS (8-41 16 Type Dynamic RAMS) for DG-32D, Apple " , TRS-80 " , H88/89 " and PET" (Tested) . . . $49.00 NEW PRICING ON OUR POPULAR DG-32D(32K Dynamic ram for Heath H8) 32K 339.00 0K 235.00 16K(y2 populated) . . 280.00 Documentation only 12.00 CP/M IS a registered trademark of Digital Research of Pacific Grove. California. Heath, HDOS, H8, H88/89 & PAM8 are registered trademarks of the Heath Company. Z80 is a registered trademark of Zilog Corp. PET is a registered trademark of Commodore. Apple is a registered trademark of Apple Computer. TRS-80 is a registered trademark of TANDY Corp. D-E ELECTRONIC □EVELOPMEIMTS Ordering Information: Products listed available from DG Elec- tronic Developments Co., P.O. Box 1124, 1827 South Armstrong, Denison, Tx. 75020. Check, Money Order. VISA or Master Charge accepted. Phone orders (charge only) call (214) 465- 7805. No COD'S. Freight prepaid. Allow 3 weeks for personal checks to clear. Texas residents add 5%. Foreign orders add 30%. Prices subject to change without notice. Circle 357 on inquiry card. BYTE September 1980 317 Circle 248 on inquiry card. IEEE-488 BUS SYSTEM BUILDING BLOCKS For Commodore PET/CBM and other computers.. TNW-1000 TNW-2000 TNW-232D TNW-103 SOFTWARE '**'^^^'-''^ CORPORATION TNW-2000 Serial Interface: $129 1 channel outpiit only Serial Interface: $229 1 channel input and output Dual Serial Interface: $369 2 channels input and output plus RS-232 control lines Telephone Modem: $389 Auto answer/auto dial. Use with DAA PTERM: A program that turns vour PET into a terminal (Use with TNW.2000, TNW-232D, or TNW 103) SWAP: Allows storage of up to 8 programs in PET memory at once. Run them in any order, PAN: A sophisticated electronic mail program (use with TNW-103) Write or call for information today: TNW Corporation 3351 Hancock Street San Diego CA 92110 (714) 225-1040 ^ A Message to our Subscribers From time to time we make the BYTE subscriber list available to other companies who wish to send our subscribers promotional material about their products. We take great care to screen these companies, choosing only those who are reputable, and whose products, services, or information we feel would be of interest to you. Direct mail is an efficient medium for presenting the latest personal computer goods and services to our subscribers. Many BYTE subscribers appreciate this controlled use of our mailing list, and look forward to finding information of interest to them in the mail. Used are our subscribers' names and addresses only (no other information we may have is ever given). While we believe the distribution of this information is of benefit to our subscribers, we firmly respect the wishes of any subscriber who does not want to receive such promotional literature. Should you wish to restrict the use of your name, simply send your request to BYTE Publications Inc, Attn: Circulation Department, 70 Main St, Peterborough NH 03458. Thank you. V^ Technicsl Formr More on Skip Chains Mark S Williamsen, 3114 Central St, Evanston IL 60201 In regards to Geoffrey Gass's Technical Forum "Mining the Skip Chain" (February 1980 BYTE, page 148), I would like to add an alternative which has several advan- tages: a lookup table. A skip chain in its simplest form (testing a single byte to access routines located within a single page [256 bytes] of memory) uses a minimum of 4 bytes of 6800-microprocessor code per test. If the skip chain is to call routines outside of that one page, then 7 bytes are required for each comparison. (See listings 1 and 2.) On the other hand, a lookup table needs a search routine (as in listing 3) of about 25 bytes and 3 additional bytes for each entry in the table if extended addressing is used. The break-even point is about 6 comparisons. Beyond that, the lookup table scheme uses less memory. It has the additional advantage that the program does not have to be reassembled to add new entries. In fact, if an end-of-table trap is used, as in listing 3, new entries can be written into a programmable read-only memory (PROM) without changing or erasing any previous data. This is ideal for use in a PROM monitor because new commands and routines can be added at any time if blank space is left following the table. ■ Listing 1 00001 NAM SKIPCH 00002 'SIMPLEST FORM SKIP CHAIN ROUTINE 00003 *GOES TO ONE OF SEVERAL ROUTINES DEPENDING ON 00004 *CONTENTSOF ACC. B 00005 *M. WILLIAMSEN l/31/'80 00006 *DEFINITON OF DUMMY LABELS TO SATISFY ASSEMBLER; 00007 FFOO INCH EQU $FF00 00008 0000 CI EQU 00009 0000 C2 EQU 00010 0000 C3 EQU 00011 0000 Rl EQU 00012 0000 R2 EQU 00013 0000 R3 EQU 00014 0000 BDFFOO START JSR INCH GET CHARACTER IN ACC. B 00015 0003 CI 00 FIRST CMP B nc\ B = CODE 1? 00016 0005 27 F9 BEQ Rl IF YES, GOTO ROUTINE 1 00017 0007 ClOO SEC CMPB #C2 B = CODE2? 00018 0009 27 F5 BEQ R2 IF YES. GO TO ROUTINE 2 00019 OOOB CI 00 THIRD CMPB IIC2 B = CODE3? 00020 OOOD 27 Fl BEQ R3 IF YES, GO TO ROUTINE 3 00021 * 00022 * 00023 * 00024 * FURTHER COMPARISONS AS NECESSARY 00025 * 00026 * 00027 * Listit ig 1 contiiuied on page 31 318 September 1980 © BYTE Publications Inc Listing 1 continued: 00028 GOOF 20 EF 00029 TOTAL ERRORS 00000 Listing 2 00001 00002 00003 00004 00005 00006 00007 FFOO 00008 0000 00009 0000 00010 0000 000 J 1 0000 00012 0000 00013 0000 00014 0000 00015 0000 00016 0000 BDFFOO 00017 0003 CI 00 00018 0005 26 03 00019 0007 7E 0000 00020 OOOA CI 00 00021 OOOC 26 03 00022 OOOE 7E 0000 00023 0011 CI 00 00024 0013 26 03 00025 0015 7 E 0000 BRA END START GET NEW INPUT IF CODE NOT FOUND NAM SKIPEX *SKIP CHAIN ROUTINE WITH EXTENDED ADDRESSING *GOES TO ONE OF SEVERAL ROUTINES DEPENDING ON •CONTENTS OF ACC. B *M, WILLIAMSEN l/31/'80 •DEFINITON OF DUMMY LABELS TO SATISFY ASSEMBLER; INCH CI C2 C3 CN Rl R2 R3 RN START FIRST SEC THIRD EQU EQU EQU EQU EQU EQU EQU EQU EQU JSR CMPB BNE IMP CMP B BNE IMP CMPB BNE IMP $FF00 INCH #01 SEC Rl #02 THIRD R2 #C2 NTH R3 GET CHARACTER IN ACC. B B = CODE 1? CONTINUE IF NO GO TO ROUTINE 1 IF YES B = CODE 2? CONTINUE IF NO GO TO ROUTINE 2 IF YES B = CODE3? CONTINUE IF NO GO TO ROUTINE 3 IF YES 00026 * 00027 * 00028 * 00029 'FURTHER COMPARISONS AS NECESSARY 00030 * 00031 * 00032 * 00033 0018 CI 00 NTH CMPB #CN B = CODEN? 00034 OOIA 26 E4 BNE START GET NEW INPUT IF NO 00035 OOIC 7 E 0000 IMP RN GO TO ROUTINE N IF YES 00036 END TOTAL ERRORS 00000 Listing 3 00001 NAM LOOKUP 00002 •COMMAND DECODER WITH LOOKUP TABLE. 00003 •GOES TO ONE OF SEVERAL ROUTINES DEPENDING ON 00004 •CONTENTS OF ACC. B 00005 •M, WILLIAMSEN l/31/'80 00006 •DEFINITON OF DUMMY LABELS TO SATISFY ASSEMBLER; 00007 FFOO INCH EQU $FF00 00008 0000 CI EQU 00009 0000 C2 EQU 00010 0000 C3 EQU 00011 0000 CN EQU 00012 0000 Rl EQU 00013 0000 R2 EQU 00014 0000 R3 EQU 00015 0000 RN EQU 00016 0000 BD FFOO START JSR INCH GET CHARACTER IN ACC. B 00017 0003 CE 0018 LDX STABLE INITIALIZE POINTER. Listing 3 cotitiinied on page 320 STOP PLAYING GAMES TRS-80 (Level II) APPLE OTHERS I Calculate odds on HORSE RACES with ANY COMPU TER using BASIC. I SCIENTIFICALLY DERIVED SYSTEM really works. TV Station WLKY of Louisville. Kentucky used. this sytem to predict the odds of the 1980 Kentucky Derby. See the Wall Street Journal (June 6. 1980) article on Horse-Handicapping. This system was written and used by computer experts and is now being made available to home computer owners. This method is based on storing data from a large number of races on a high speed, large scale computer. 23 factors taken from the "Daily Racing Form" were then analyzed by the computer to see how they influenced race results. From these 23 factors, ten were found to be the most vital in determining winners. NUMERICAL PROBABILITIES of each of these 10 factors were then computed and this forms the basis of this REVOLUTIONARY NEW PROGRAM. I SIMPLE TO USE: Obtain "Daily Racing Form" the day before the races and answer the 10 questions about each horse. Run the program and your computer will print outt he odds for all horses in each race. COMPUTER POWER gives you the advantage' I YOU GET: 1) TRS-80 (Level II) or Apple Cassette 2) Listing of BASIC program for use with any computer. 3} Instructions on how to get the needed data from the "Daily Racing Form" 4) Tips on using the odds generated by the program. 5) Sample form to simplify entering data for each race. MAIL COUPON OR CALL TODAY 3G COMPANY, INC. DEPT. BT (503) 357-9889 RT. 3, BOX 28A, GASTON, OR 97119 Yes, I want to use my computer for FUN and PROFIT. Please send me programs atSl9.95each. _-- I need a n TRS-80 Cassette or n Apple Cassette. W^ Enclosed is; n check or money order □ Master Charge n Visa Card No NAME Exp. date ADDRESS _ CITY . STATE _ _ZIP. START USING YOUR COMPUTER FOR FUN and PROFIT! A Selection of the Computer Professionals Book Club MICROCOMPUTER INTERFACING Principles and Practices G. Jack Lipovski, University of Texas ' 'A wide range of interfacing and use topics are treated in depth, and the book acquaints the reader with relevant techni- cal terminology. " —Terry Ritter, Motorola Semiconductor Products, Inc. 448pp. ISBNO-669-03619-6 $24.95 MICROPROCESSORS AND MICROCOMPUTER SYSTEMS Dwight H. Sawin III 288pp. ISBNO-669-00564-9 $21.00 REAL-TIME PROGRAMMING WITH MICROCOMPUTERS Ronald C. Turner, American Sign and Indicator Corporation 192pp. ISBN 0-669-01666-7 $17.95 BASIC COMPUTER LOGIC John Scott, Cossor Electronics Limited ISBN 0-669-03706-0 Spring 1981 Lexington Books SLexIngtonBooks, D. 0. Heath and Company 125 Spring Street, Lexington, MA 02173 HEATH (617)862-6650 (212)924-6460 Call our toll-free number, 800 428-8071 Circle 249 on inquiry card. September 1980 © BYTE Publications Inc 319 Circle 250 on inquiry card. General Ledger Payroll Accounts Receivable & Payable Flexible and sophisticated business software that is among the highest quality on the market. Originally developed by OSBORNE & ASSOCIATES and rapidly becom- ing a standard. Our service is support. We will send you these programs with the proper I/O and CRT specific subroutines for your hardware configuration. Get back to business and leave the programming to us. Include hard- ware description with order. • Accounts Receivable and Payable 145.00 • Payroll (California) 145.00 • Non California state tax calculations (please inquire) 1 5-250.00 • General Ledger 145.00 • Multiple profit center option for G/L 25.00 • Manuals (each) 20.00 All programs in CBASIC under CP/M (includes source) These programs are up and running on the follow- ing computer systems: Altos, TRS-80 MOD II (under CP/M), Northstar, Vector Graphics, Intertec Super Brain, Cromemco, and others. Synergetic Computer Products 508 University Ave • Palo Alto, CA 94301 (415)328-5391 Visa • Mastercharge • COD • Certified Check CP/M is a trademark of Digital Research eiJTE Back Issues for sale The following issues are available: 1976: July and November 1977: March, May thru December 1978: February thru October, December 1979: January thru December except March 1980: January to current issue except February Cover price for each Issue through August 1977 is $1.75 Domestic; $2.75 Canada and Mexico; $3.75 Foreign. September 1977 through October 1979 issues are $2.50 Domestic; $3.25 Canada and Mexico; $4.00 Foreign. November 1979 to current is $3.00 Domestic; $3.75 Canada and Mexico; $4.50 Foreign. Send requests with payment to: BYTE Magazine 70 Main St, Peterborough NH 03458 Attn: Back Issues Listing 3 continued: 00018 0006 A600 GCl LDA A X GET CODE FROM TABLE. 00019 0008 08 INX INCREMENT POINTER. 00020 0009 81 FF CMP A #$FF IF END OF TABLE 00021 OOOB 27 F3 BEQ START GET NEW INPUT. 00022 OOOD 11 CBA DOES ACC. B = CODE? 00023 OOOE 27 04 BEQ FOUND IF YES. GO TO ROUTINE. 00024 0010 08 NEXT INX INCREMENT POINTER TO 00025 0011 08 INX NEXT CODE IN TABLE 00026 0012 20 F2 BRA GCl IF NO. 00027 0014 EEOO FOUND LDX X LOAD POINTER FROM TABLE 00028 0016 6E 00' IMP X AND GO TO ROUTINE, 00029 'LOOKUP TABLE STARTS HERE: 00030 0018 00 TABLE FCB CI CODE 1 00031 0019 0000 FOB Rl ADDRESS OF ROUTINE 1 00032 001 B 00 FCB C2 CODE 2 00033 OOIC 0000 FOB R2 ADDRESS OF ROUTINE 2 00034 OOIE 00 FCB C3 CODE 3 00035 001 F 0000 FOB R3 ADDRESS OF ROUTINE 3 00036 * 00037 * 00038 * 00039 'FURTHER TABLE ENTRIES AS NECESSARY 00040 * 00041 * 00042 * 00043 0021 00 FCB CN CODEN 00044 0022 0000 FOB RN ADDRESS OF ROUTINE N 00045 END TOTAL ERRORS 00000 Beware of Interrupts Dave Feldman, 1856 Viking Way, La Jolla CA 92037 I have read with interest Michael McQuade's article "A Fast, Multibyte Binary to Binary-Coded-Decimal Con- version Routine" (February 1980 BYTE, page 106). I wish to make the following comment regarding the program presented in listing 1, on page 110. If the program is run in an environment in which inter- rupts exist, the user may experience difficulty in obtain- ing correct results should an interrupt occur when execu- tion is just before RLOOP or just after LAB17 (in the area of the DCX SP instructions). The data on the stack (which is "recovered" by use of the two DCX SP instruc- tions) will be overwritten by the return address saved when execution is transferred to the interrupt service routine. To prevent this problem, replace each occur- rence of DCX SP DCX SP with a PUSH H or keep inter- rupts off while the subroutine is executing. I recommend the former. ■ 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 correspondents supply their full names and addresses to be printed with their commentaries. We also ask that cor- respondents supply their telephone numbers, which will not be printed. 320 September 1980 © BYTE Publications Inc lechnicsl Fopum Bending BASIC in a Recursive Form Colin Newell, Newcastle, Australia I read Stanley Swizer's "The Towers of Hanoi: Solu- tion Using BASIC Recursion" ("Programming Quickies," March 1980 BYTE, page 240) with interest. He has shown us how to solve this problem in BASIC; however, my BASIC does not incorporate a stack. So here is my way of solving this problem (listing 1). Listing 1 10 INPUT ^^NO OF DISKS ";N 20 LET! = 1 30 LET J = 3 40 GOSUB 100 50 GOTO 300 100 IF N = THEN RETURN 110 LET N = N - I 120 LET J = 6 - I - J 130 GOSUB 100 140 LET J = 6 - I - J 150 PRINT *^MOVE TOP DISK ON TOWER 160 LET I = 6 - I - J 170 GOSUB 100 180 LET I = 6 - I - J 190 LET N = N + 1 200 RETURN 300 END ';I;" TO TOWER "; J READY RUN NO OF MOVE MOVE MOVE MOVE MOVE MOVE MOVE DISKS ? 3 TOP DISK ON TOP DISK ON TOP DISK ON TOP DISK ON TOP DISK ON TOP DISK ON TOP DISK ON TOWER TOWER TOWER TOWER TOWER TOWER TOWER 1 TO TOWER 3 1 TO TOWER 2 3 TO TOWER 2 1 TO TOWER 3 2 TO TOWER 1 2 TO TOWER 3 1 TO TOWER 3 Programming in the Dark Jeffrey Sainio, 143 N Moreland #106, Waukesha WI 53186 Robert Glaser's article on programming 2708-type read-only memories ("Program Those 2708s," April 1980 BYTE, page 198) is a boon to those of us who are in- terested in programmer boards with three-figure price tags. Having built a similar board, let me offer some pointers I have learned: • 2708s program faster in the dark. This holds true for the devices manufactured by Intel, Texas Instruments, and Motorola that I have used. The speed difference between total darkness and bright incandescent light is over ten to one. The devices also read Os more easily in the dark (ie: a marginally programmed bit may read correctly in the dark, but not in the light). • Programming can be done interactively. By pulling the + 26 V and CS (chip select) lines low, a byte of infor- mation can be read through an input port. If a logical exclusive-OR of the original data and the read data yields all Os the byte does not need programming. The result of the exclusive-OR may be inverted and ORed with the desired data, then tested. If the result is anything other than hexadecimal FF, the device should be erased. If a programming pulse is to be applied, remember to set CS at -f 12 V before applying the + 12 V; and remember that +26 V must be turned off before reading the device. By using these techniques, I can program a 2708 in three to fifteen seconds. After an entire programming loop has been executed with no false bits indicated, I shine a high-intensity lamp through the device's window to catch any marginal bits. This ensures that all bits are programmed solidly. Having used this programming technique on devices rated at 450 ns installed in a Z80 system (running at 4 MHz with no WAIT states), I can say that the method may not seem "kosher," but it is fast and error-free. « Boards for S- 100 BUS from S.C. Digital "INTERFACE : 1" Serial. Parallel. ROM. RAM. Cassette Inter-face Board Assembled Er Tested $229 Introductory Price Features: MODEL - 3SPC • 3-Serial with hardware UARTS, RS232-C or 2Gma Current loops • 1- Parallel I/O with full handshakes, polatity is SW selectable • Built in 4K ROM. 4K RAM Capability with SW disables (for2708's. 2114' s. ROM, RAM not supplied) • Built in Kansas City cassette inter-face usable to 1200 BAUD • Interrupts built in on all 4 inputs • On board BAUD rate osc generates 19.2K. 9.6K. 4.8K. 1.2K. 300. 110 or 134.5 BAUD • Switch selectable address, ports and BAUD rates liiip- ' *Wy m "UNISELECT" 16K Static RAM Board Assembled & Tested $255 with200nsec Low Power Memory Chips Features; MODEL - 16K US • Fully static, uses2114L'S • 16K Block Addressing & Bank Select • Univeral Bank Select by port and bits, compatable with CROMEMCO, ALPHA MICRO, NORTH STAR, MARINCHIPS. etc. • Address, Port. Bits, all SW Settable All boards meet lEEE-SlOO standards Fully socketed, solder masks, gold contacts, and guaranteed for one full year. Delivery: from stock to 72 hours. Ordering: You may call for M.C.. Visa or C.O.D. orders. ( Add $4.00 for C. 0. D. ) Personal checks o. k.. but M. 0. speeds shipment. Takes 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 5'/*% sales tax. O.E.M. PRICING AVAILABLE. DEALER INQUIRY INVITED S.C. Digital P.O. Box 906 Aurora. IL 60507 Phone: (312) 897-7749 Circle 251 on inquiry card. September 1980 © BYTE Publications Inc 321 PpograoBflDKig (InicMes 6502 Loop Control Gordon Campbell, 36 Doubletree Rd, Willowdale, Ontario, Canada For clarity, the best way to loop through a field is to start at the beginning and stop at the end. It is important to be able to change the content or length of the field without having to change the code that handles it. Some people use a marker byte such as hexadecimal 00 to stop the loop; however, if you make your assembler work for you, this is unnecessary. Listing 1 is an example of how to make your assembler perform this task. The X register is used to index through a field. The code is set up so that when the register hits zero, execution is terminated. Thus, begin by loading the register with 256 minus the length of the field. Then work through the field from start to end by loading the ac- cumulator with the byte stored at the end of the message minus 256, plus the contents of the X register. The result is that when the X register hits zero, you are done. The code shown has been used with two assemblers: From S-lOO to lEEE-488 urn , i I ]ii>J; P&T-488+ S-100 computer = Intelligence for your Instrumentation System The P&T-488 permits an S-100 computer to operate as a talker, listener, or controller on the IEEE-488 instrumentation bus for less than half the cost of calculator-based systems. Software packages which give access to the 488 bus from high level lan- guages such as BASICareavailable for CP/M, North Star DOS /BASIC, and Cromemco CDOS. Or "roll your own" system with the custom system package of assembly language drivers. P&T-488, assembled and tested, + any software package: S450 (domestic USA) PICKLES & TROUT P.O. BOX 1206, GOLETA, CA 93017, (805) 967-9563 I^ROU'T Carl Moser's ASSM/TED, and Dan Fylstra's 6502 Assembler in BASIC, published by Personal Software. Fylstra's assembler generates an error message on the first pass if MSG and MSGEND follow the code that uses them, but then produces correct object code. Of greater concern is the fact that both assemblers do not notice if MSG is greater than 256 bytes long. This should be an er- ror condition that raises a diagnostic. In both cases the only result is that incorrect code is produced. 0010 .BA $7000 0020 .OS 0030 .LS 0040 ** HOW TO SCAN A FIELD ** 0050 (MAKE YOUR ASSEMBLER WORK) 0060 0070 THE OPTIMUM METHOD OF LOOP 0080 CONTROL ON A 6502. MAXIMUM 0090 OF 256 BYTES OF DATA. 0100 0110 0120 0130 0140 7000- A2 Fl 0150 LDX ii Sorting ;W ith a Catch Paul T Brady, 91 Marcshir e Dr, Middletown NJ 07748 So much has been said concerning various sorting algorithms that it hardly seems possible to be able to con- tribute to this topic; and yet, in a small business (a nature 322 September 1980 © BYTE Publications Inc Circle 252 on inquiry card. center, to be precise), we have developed a sorting routine that handles accounting entries, mailing list en- tries, etc, at a speed that leaves fancy algorithms in the dust. The special beauty of this technique is that it is very simple, and involves only a slight modification of the usually terribly inefficient brute-force bubble technique. The routine has another advantage — it will not disturb the order of ties. For example, if one orders by zip code, it will not rearrange entries having the same zip code. This is an advantage if the list were previously alphabetized and you wanted to retain alphabetization within zip codes. There is a catch. This routine is absolutely terrible for ordering a true random list. The routine is designed to handle a list that already is nearly in order, and you want to add a few extra items. But this is exactly the case in a mailing list, in which you add 20 names to a 1500-name list, or in accounting, in which you add 15 transactions to a 60-item list. The Algorithm The algorithm works as follows: assume that you have an array of L items, A(I), I = 1 to L. In the standard bub- ble sort, you compare A(l) with A(2). Assume that you want the list ordered from smallest to largest entry. Then, if A(l) < = A(2), leave them alone, but if A(l) > A(2), reverse them and proceed pairwise down the list. The last comparison made is between A(L — 1) and A(L), reversing them if A(L — 1) > A(L), You have just made L — 1 pair- wise comparisons. For those unfamiliar with this method, a moment's thought should demonstrate that in this first pass you have guaranteed that the largest entry has sunk to the bottom. That is, A(L) now is the largest entry. In subse- quent passes, it is no longer necessary to test anything against A(L). So, the second pass ends by comparing A(L — 2) with A(L — 1). But now, you have guaranteed that the second biggest entry is in the L^l slot, so each successive pass requires one less comparison. Even with the shortcut of cutting each pass to be one shorter than the previous pass, this method still takes a long time. But now consider the following. Suppose, dur- ing the first pass of L — 1 comparisons, we check to see just how well ordered the list already is. We will set up a window in which W equals the first pair that was ordered, and X equals the last pair. Suppose the list con- tains 85 items, but after the first pass, W = 26 and X = 34. This means that everything beyond 34 is already ordered. Items earlier than 26 may not be completely in order when considering later items, but the very next pass can compare entry twenty-five with entry twenty-six; ie: at W — 1. So, we have a window that will ascend to the top of the list. Further, on each successive pass we will reevaluate W and X. As soon as X <= 1, we can stop. (Note: X can equal zero in the special case that the entire list was already in order before you invoked the routine.) The Program This idea is so simple that it cannot be new; yet, I have not seen it mentioned, and even if it is published elsewhere, it is worth repeating. The code in listing 1 is for North Star BASIC, in which the semicolon separates statements on the same line. W and X have already been defined. T, Tl, and T2 are temporary variables. I is an in- dex variable, and A (I) is the array. The A (I) could also be pointers to string variables; the technique is clearly not limited to ordering numbers. A final comment. This routine is at its very best if the list is already completely ordered before calling it; it makes one pass through the list, discovers that the list is already ordered (X = in statement 135), and quits. This is not at all a ridiculous situation. We have several pro- grams that require ordered data in files, and call the sort routine whenever a "write" is called for, even if nothing was done to disturb the order. In such instances, the sort is only a momentary delay. Listing 1: A bubble sort with a window. This routine is designed specifically to sort lists with only a few entries out of order. It can even be used to check a list quickly to ensure that all entries are ordered. The main attraction, though, is its simplicity; the actual North Star BASIC code is only eight lines long. 100 W = 2;X = L;REM W = UPPER WINDOW BOUND, X = LOWER 105 FOR 1=1 TOL 110 T1=X;X=0;IF W<2THEN W = 2;T2 = W-1;W = 115 FOR J = T2TOTl-l;REM BEGIN AT T2. STMT 110 ASSURES T2 > =1. 120 IF A(I) < = A(I+ 1) THEN 135 125 T = A(I);A(I) = A(I+1):A(I+1) = T;REM. OUT OF ORDER, REVERSE. 130 X = J;IF W = THEN W = J; REM W = IMPLIES FIRST REVERSAL. 135 NEXT;IF X < = 1 THEN EXIT 145;NEXT 140 STOP;REM FOR COMMENT ONLY - WILL NEVER BE REACHED 141 REM WILL NEVER FINISH SECOND *^NEXT" OF 135 145 REM ROUTINE ENDS HERE, LIST IS ORDERED. ■ DATA DISK SYSTEMS CP/M* FOR NORTH STAR SYSTEMS CP/M 2.2 - The Industry slarCard software bus' specially lailofed lor IheNorlhStardisk systems and 8080, 8085. ZBD m(crocompulers Fjlly supports all standard Nonri Slar I/O and smgle, double or quad capacity disk drives A mmimum ol 24K ol continuous ram memory starting al location zero is required The (oltowing Digital Research ,t.i.a VERBATIM minidisks (tOlSOtlO) S2«.95 Shipping S2 00 CO S200 DATADISK SYSTEMS, P.O. BOX 195, POWAY, CA 92064. (714) 578-3831 Circle 253 on inquiry card. September 1980 © BYTE Publications Inc 323 DISCOUNT PRICES 16K APPLE II 959.00 32K APPLE II 1024.00 48K APPLE II 1089.00 DISKWCONTROLLER 520.00 DISK ONLY 450.00 APPLESOFT CARD 159.00 INTEGER CARD 159.00 PASCALSYSTEM 440.00 SILENTYPE PRINTER 525.00 RAM MEMORY FOR TRS-80, APPLE II 16KSET4116's 65.00 APPLE II COMPUTERS BSkS NORTH STAR COMPUTERS HRZ-1D-32K-KIT 1545.00 HRZ-1D-32KASM 2045.00 HRZ-2D-32KKIT 1895.00 HRZ-2D-32K-ASM 2360.00 VERBATIM DISKETTES BOX OF 10 5%" 29.50 BOX OF 10 8" 39.50 FREDERICK COMPUTER PRODUCTS MUNICIPAL AIRPORT FREDERICK, MD. 21701 (301) 694-8884 TSl ^^^jnnrrisinnnnnnnnnnsir^ .To further improve service to our customers v^e have installed a toll-free '^WATS line in our Peterborough, New Hampshire office."^ If you would ike to order a ' bscription to\ BYTE, or if Toll-free \ ^^^^ \ WXJWM EM %^%^ \ question relat-> to a BYTE ' I BYTE'S lSUC Subscriber W.A.T.S. Line ed (800)258-5485 We thank you and look forward to serving you. subscription, ^you are invited^ to call* (800)258-5485 between 8:00 AM and 4:30 PM Eastern Time. (Friday 8 AM -Noon). * Calls from conti- nental U.S. only. iv^ 9178; Ppograoxnkig OoiddGs Notes on Absolute Location Interfaces to Apple Pascal Daniel D Sokol, 211 Fall Creek Dr, Felton CA 95018 After seeing the March 1980 BYTE Editorial ("Hunting the Computerized Eclipse," page 6), I realized that many other users of Apple Pascal have encountered the same problem I have: the difficulty in accessing memory loca- tions directly. I have written two programs that help to minimize this problem. Listing 1: A UC5D Pascal compilation unit called PEEKPOKE lofiicfi provides the modules PEEK and POKE that allow access to arbitrary memory locations. Care should be exercised in using this routine, because data vital to the operating system may be inadvertently modified. (*SS+,LPRINTER:* ) PEEK and POKE Dan Sokol 3 Dec 79 unit PEEKPOKE; intrinsic code 26; inter face procedure POKE (var ADDR , DATA: integer ) ; function PFEKCvar ADDR : i nteqer) : inteqer; implementation type PA = packed array[0..1) of 0..2S5; MAGIC = record case boolean of (INT; integer); : (PTR:*PA); true : false end; var CHEAT: MAGIC; procedure TEST(var DATA: inteqer ) ; forward; procedure POKE; beal n TEST (DATA) ; CHEAT.INT:=ADDR; CHEAT. PTR" [0] :=DATA; function PEEK; begin CHEAT. INT:=ADDR; PEEK: =CHEAT. PTR* [01 ; end; This program has been t^esiqned to be adiied to the Pascal SYSTEM. LIBRARY. See section 4.2 in the reference manual for info on the Librarian. (* I used segment 26 *) Format is : *) POKE(addr,data); *) data:=PEEK(addr); Both addr and data must be IMTEGF:R variables fnot constants) To use in a proqram you must follow the proqram name with : USES PFiKKPOKK; *) (* this defines a variant *) (* record which will map *) (* to an absolute hardware *) (* address in the Apple. *) procedure TEST; begin DATA :=abs (DATA nod 2!>6 ) ; {* MAIN PROGRAM *) beg in (* DUMMY PROGRAM *) end. (* This procedure assures *) (* only valid data wi 1 3 *) (* get poked •) 324 September 1980 © BYTE Publications Inc Circle 254 on inquiry card. The first program, entitled UNIT.PEEK.TEXT (shown in listing 1), is a library intrinsic that performs the same functions as PEEK and POKE in BASIC. It uses the var- iant-record technique to access arbitrary addresses in memory. The second program is called CALL. ASSY. TEXT (shown in listing 2). It is an assembly-language linkage which allows the user to call, from a Pascal routine, an external (non-Pascal) assembly-language program at an arbitrary address in memory^ It is, of course, possible to call an assembly-language module that is linked into a Pascal program, such as this module itself, but the linker has no provision for fixing an absolute address of the called routine. Thus this routine is required as an escape to routines found at locations fixed by hardware, such as the read-only memory regions of the typical Apple in- put/output (I/O) cards. Listing 2: CALL, a UC5D Pascal system assembly-language pro- gram for a 6502 processor. This routine will call an arbitrary ab- solute address, such as an address associated with a read-only memory routine in an interface card, which is not normally accessible from Pascal. As in listing 1, care should be exercised in using this routine. PROGRAI^ TO CREATE A CALL FUNCTION FOR PASCAL IM THK APPLF; Use this assembly lanquqe proaram to call programs that are not normally accessable from Pascal. To use: ASSF;mBLF: this proaram and save the code file. Define a PROCEDURE in your proaram as follows - PROCEDURE CALL(addr); EXTFIRNAL; addr nust be an integer variable. Compile your program and then run the linker. When asked for the LIB. name type the name of the save code file. WARNING : ANY PROGRAM THAT CHANGFlS MEMORY LOCATIONS MAY INTRPFFRi': WITH THF PASCAL OPERATING SYSTEM. .title: " CALL SUBR - 15 FEB 80 - DAN SOKOL" .MACRO POP PLA STA %1 PLA STA %1 + 1 .ENDM .MACHO PUSH LDA %1 + 1 PHA LDA %1 PHA .ENDM PROC CALL.l proced jre CALL (ADDR : inteaer) ; external RETURN .EQU MYCALL .EOU ? POP RFTURN ; SAVF PASCAL RFTURM PLA STA KETURM PLA STA RFTURN+1 POP MYCALL ; SAVF OUR CALLlwr; AD PLA r,-VA MYCALL PLA STA r-iYCALL + l PUSH RETURN ; PUT BACK ON STACK; LDA RFTURN+1 PHA t.DA RFTUR-y PHA JMP ''MYCALL ; JUMP TO USKR PROCRA COMPUTER ENTHUSIASTS, CLUBS] DISCOVER BADGE POWER . BIONIG BjUXTOlir MEMBER 1 Discover the power to inform, surprise, humor, protest or identify. Badge- A-Minit gives you that power and more! This is the system that started a badge and button making revolution. With the patented, BUT-N-LOK dies, sturdy hand die press and badge parts (that cost just pennies each), you create pinback badges. Use any slogan, emblem or photo-it's quick it s easy, it's inexpensive. Make one or one hundred, any time, any place. LOWEST PRICE EVER. Here's a complete badgemaking system at a new, low price. Starter kit includes steel and Lexan die press; precision mold- ed, color-coded dies; quality, virgin metal badge parts; and illustrated instructions. 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And TeleCom can let you have just that., anytime you want! f<^ "TeleCom" is a modem-control software package designed to allow the user of any CP/M* (version 1.4 or earlier) or Cromemco CDOS* (version 2.17) equipped microcomputer remote operation over standard telephone lines. These are some of TeleCom's features: 1. Dial and connect to any Bell 103A compatible computer system; 2. Transfer any ASCII text file or data between systems; 3. Remote operation of the TeleCom equipped system through standard telephone lines; 4. Automatic dialing of three user-defined telephone numbers by a single-key control. TeleCom can also be used as the basis for other user programs which require con- nection to a remote system. The user can run other computer programs on his system while still remaining connected to the remote system. For example this can be a program to send daily cash sales or customer records. Hardware Requirements: TeleCom can operate on any 8080, 8085, or Z80 based computer system equip- ped with CP/M* or any CP/M* derivative (IMDOS, COGS*, etc.). TeleCom uses 2K of memory space above CP/M. A D.C. Hayes Micromodem-lOO* or 80-1 03A* board is also required. Why don't you or your computer give us a call, we'll be glad to tell either of you all about the TeleCom package. ComputerLand of Niles, Ltd. Cr^^ / Circle 255 on inquiry card. September 1980 © BYTE Publications Inc 325 Technbsl hmsoi A Lowercase-to-Uppercase Converter Roger L Degler Motorola Inc Mail Drop M2 90 2200 W Broadway Mesa AZ 85202 Many ASCII-encoded keyboards are capable of generating both upper- case and lowercase codes. Many of these contain a jumper option that will disable the lowercase characters, and generate their uppercase counter- parts. But some keyboards do not offer this option, and trying to use an uppercase/lowercase keyboard on a system that requires only uppercase characters becomes very frustrating. Of course, the uppercase codes may be generated singly by pressing the shift key. The problem with this is trying to remember to press the shift key every time you want to enter an uppercase letter and to leave it unpressed when you want to enter a number or lower- case symbol. Mistakes are inevitable. However, there are two possible solu- tions: convert the lowercase characters to uppercase with addi- tional software in the character input routine; or perform the conversion with a hardware circuit between the keyboard and the computer. The software approach is the better alternative. The software, shown in listing 1, is extremely simple and can be as versatile as the user desires it to be. For example, by setting or clear- ing a software-flag location, the lowercase characters may be enabled or disabled. This assumes that the user has access to the computer's character-input routine and that the routine can be modified. The hardware conversion method, on the other hand, is somewhat less versatile and requires more effort to implement. Versatility is lost because alternation between the two modes, that is, allowing and disallowing lowercase, requires the physical act of Listing 1: Software routine to convert from lowercase to uppercase ASCII (American Standard Code for Information Interchange). This routine is relocatable to any address in memory. It assumes that the character to be converted resides in the ac- cumulator; the result is left in the accumulator. The routine is written for the 6800 microprocessor and requires only 13 bytes. Hexadecimal Hexadecimal Instruction Address Code Label Mnemonic Operand Commentary 0100 84 7F CNVT ANDA #$7F Mask to 7 bits. 0102 81 61 CMPA #$61 Check for lowercase. 0104 2D 06 BIT NOCNVT Do not convert if not. 0106 81 7A CMPA mA Do not convert special characters 0108 2E 02 BGT NOCNVT at end of ASCII code table. OlOA 8A 5F ANDA #$5F Convert to uppercase. OlOC 39 NOCNVT RTS Return. UCSD Pascal* for the INTE^TEC SUPE^BRMN Certified by Softech Microsystems Our package includes: $400 compi operating system compiler screen editor filer library Z80 assembler user manual Jensen & Wirth Pascal Reference Manual Bowles' Beginners Guide to UCSD Pascal Nocsis mm(pmw[m mmmm 615 Third Street, San Francisco, CA 94107 Telephone: (415)495-7440 •Trademark of the Regents of the University of C ^Trademark of Intertec Data Systems 326 September 1980 © BYTE Publications Inc Circle 256 on inquiry card. ^o- B6C>- BSO- B4[3>- B3|Z>- BlC>- BOO- TO KEYBOARO INTERFACE (PlA) 4 7K (TYPICAL FOR 10) E> -lZ> strobe -\ ^ STROBE Fl A< B IN A-B IN A>B OUT TEy H 3b jo— A>B IN A66 -Ob4 -C>B3 HZ>B2 -C>B1 -[I>BO iiO^)— E>^ Number Type + 5 V GND IC1 MC14585 16 8 IC2 MC14585 16 8 IC3 MC14011 14 7 IC4 MC14001 14 7 Figure 1: Schematic diagram for the lowercase/uppercase hardware interface. This circuit assumes that there is a parallel interface be- tween the keyboard and the microcomputer. All integrated circuits are complementary metal-oxide semiconductor (CMOS) types for low power consumption. ICl and IC2 are 4-bit comparators. Switch SWl transfers the keyboard between an uppercase-only mode and a mixed uppercase-and-lowercase mode. These two modes are achieved with SWl closed and opened, respectively. upper (jiqit B6 1 1 1 1 \ Hh 1 1 1 1 lower digit \ ^84 1 1 2 1 3 4 1 5 6 1 7 V B B B B^ \ 3 2 1 \ NUL DLE SP ® P ' P 1 SOH DC1 I 1 A Q a q 1 2 STX DC2 " 2 B R b r 1 3 ETX DC3 # 3 C S c s 1 4 EOT DC4 $ 4 D T d t 1 5 ENQ NAK % 5 E U e u 1 1 6 ACK SYN & 6 F V f V 1 1 7 BEL ETB ' 7 G w g w 8 BS CAN f 8 H X h X 9 HT EM ) 9 -1 Y i V 1 A LF SUB J z j z 1 B VT ESC + K f k { 1 C FF FS < L \ 1 1 1 D CR GS — = M 1 m } 1 1 E SO RS > N A n 1 1 F SI US / 7 DE Figure 2: ASCII code table. When converting from lowercase to uppercase, by either hardware or software, only hexadecimal codes 61 thru 7 A should be changed. The change to uppercase is made by setting bit B5 to or, equivalently, by subtracting hexa- decimal 20 from the code. All other codes should be left intact. flipping a switch. Thus, a program calling for large quantities of both uppercase and lowercase input will be inconvenient to run. But this should be no more trouble than shifting on a regular typewriter. In any case, hard- ware design should be kept as simple as possible. The circuit in figure 1 meets these desirable requirements. Once con- structed, it is connected between the keyboard and the computer. It will convert the lowercase letters "a" through "z' into their uppercase equivalents if switch SWl is closed. If SWl is open, all codes, whether uppercase or lowercase, are passed directly to the interface. Construction is noncritical, and very little power is needed due to the use of CMOS inte- grated circuits. ■ September 1980 © BYTE Publications Inc 327 A BASIC Floppy-Disk Accounting System OTHER PUBLICATION OTHER 10 riIMB( 19) f 1(2.19 , 11 )tT$(440) fD$(33) :20T$( If 55)-"CASH SECURITIES RECEHJABLES INVENTORY OTHER ;'50T$( 56f 110) - -PLANT MACHINERY EQUIPMENT RAW STOCK OTHER AOT^ (Illy 16;:; ) =^ ■ PAYABLES TAXS PAY . LOANS PAY . OTHER PAY . DEBENTURES 50T$( 166f220)=="LT LOANS NOTES OTHER LT STOCK *:IPARR. EARNINGS A0T$(221 f275) = "SL'RU. PEES ROYALITES ASSETS SOLDSOFTWARE OTHER SALES 70T$( 276. 330)==^ 'INVENTORY ASSETS SOLDDEPRECIAT, OTHER f?0T$(3;n f 3{;!^^)- "RENT li-LECTRlC GAS TELEPHONE 90T$ ( 386 T 440) = "SUPPLIES POSTAGE TRANSPORT. SALARIES :l 00 I " B A l. A N C E SHE E T A C; C l.) U N T S - - 1 N C C) H li: STATEMENT A C C DUN T S " :120 FORA = OT019\B^^A+20\T1:==A\GOSUB1200\T2==T1\T1^^B\GOSUB1200 130 ';<:,;]: rAf" ■ .T$(T2-10rT2) r ■ ^:^= "f^lSIfBf" ■ f T$(Tl-10f TDXNEXT 140 INPUT" rO END OR 1 TO ERASE A FILE '? " » AMFA^^OTHENEND .l.::;0 GGSUB1000\G0SUB1300\!F$r " HAS BEEN ERASED "\END 1000 .rNPUT"FlLE : ■ fE 1 l^- K' A ■^■- 1 2 \ f G R B ■■'.-. T D 1 9 \ F C) R C == T C) 1 1 1320 IJRITE#OtI(A.BtC)\NEXT\NEXT\NEXT\CLOSE#0\RETURN r^EADY Listing 1: LI ST J, a program designed to display the codes used in the au- thor's floppy disk based accounting system. The program also allows the user to erase all data from a given file name. LI ST I is used in the article example to keep track of the business transactions of the jjR Company, a fictitious organization. BALANCE SHEET ACCOUNTS === INCOME STATEMENT ACCOUNTS Joseph J Roehrig JJR Data Research POB 74 Middle Village NY 11379 o CASH :.-^::= 20 SERV. FEES 1 SECURITIES :.::r; 21 ROYALTIES o RECEIVABLES :=-: 22 ASSETS SOLD 3 INVENTORY :=:= 23 SOFTWARE 4 OTHER :-- 24 OTHER SALES 5 F'LANT -.=. 25 INVENTORY 6 MACHINERY :=::, 26 ASSETS SOLD 7 EPUIF'MENT ::=■•::: 27 DEF'RECIAT. a RAW STOCK = =: 28 OTHER 9 OTHER :=:-■ 29 OTHER 10 PAYABLES = = 30 RENT 11 TAXS PAY. :==; 31 ELECTRIC 12 LOANS PAY* :=:= 32 GAS 13 OTHER PAY. :=;.- 33 TELEPHONE 14 DEBENTURES := = 34 PUBLICATION 15 LT LOANS = -•= 35 SUPPLIES 16 NOTES = = 36 POSTAGE 17 OTHER LT ti=::z 37 TRANSPORT. 18 STOCK $1PAR := = 38 SALARIES 19 R. EARNINGS = :z: 39 OTHER TO END OR 1 TO ERASE A FILE ? BUD INF-UT ERROR-RETYPE TO END OR 1 TO ERASE A FILE ? 1 FILE : BUD BUD HAS BEEN ERASED READY Listing 2: A sample run of LISTI, showing codes used for the balance sheet accounts and income statement accounts. The purpose of this article is to present a complete accounting system for a micro- processor equipped with a floppy disk or an- other storage device. This article gives com- plete listings for all programs and focuses on the operation rather than on the design of the system. The programs are written in North Star BASIC on an IMSAI 8080 sys- tem with 24 K of programmable memory. As a model we use a fictitious company (JJR) that used the Micro Accounting Sys- tem in 1976. During this period the journal entry, balance sheet, budget input and gen- eral list programs are introduced. Income statement and budget programs are examin- ed later in the article. The magnitude of the figures used and the number of inputs shown are kept to a minimum for the sake of clar- ity. In order to design an accounting svstem, one must decide how many accounts to han- dle. The system being presented has 20 bal- ance sheet accounts and 20 income state- ment accounts. The computer automatically clears out all income statement items to retained earnings. For the 20 balance sheet items, only a year-to-date figure is main- tained. However, all income statement items are broken down into three possible departments: — Administration 1 — Local Sales 2 — National Sales Furthermore, monthly activity is tracked for each income statement item. A file con- tains only one year's worth of data. The North Star Microfloppy Disk I used has a capacity of 35 tracks. Each track con- 328 September 1980 © BYTE Publications Inc 10 niMBCl?) f I (2 .19^11 ) f r$(440) fD*(33) :l:. dim j( 100^4) 20T$( It 55)-="CASH 30T$( 56f 110)= "PLANT 40T$ ( 1 1 1 f lAliv ) = ■ PAYABLES 7j01i(166r220>-^'LT LOANS SECURITTES RECEIVABLES I N^^ENTORY OTHER MACHINERY EQUIPMENT RAU STOCK OTHER TAXS PAY. LOANS PAY. OTHER PAY. HEPENTURES NOTES OTHER LT STOCK $1PARR. EARNINGS OTHER SALES OTHER PUBLICATION OTHER ■ f A$\ I ■ DEPT REFERENCE" 60T$(221f275) -'SERV. FEES ROYALTIES ASSETS SOLDSOI- TUARE /0T$ (276 f 330)== 'INVENTORY ASSETS SOLDDEPREC lAT . OTHER {30T$(331 f3e5)^^"RENT ELECTRIC GAS TELEPHONE 901$ ( 386 f 440)^= "SUPPLIES PG.STAGE TRANSPORT. SALARIES 100 GOSUBlOOOXGOSUBllOO 140 INF-UT'MONrn ; "fM\M-M-l 150 IFM=:00RM = L1THEN140 160 I'lNPUi: $Ai-10UNTf DEBIT ACC* f CREDIT ACC*f DEPTtf REF*" 170 !"OfOyOfOfO ENDS INPUT"\A==0 180 ! 'ENTRY *" r%4IfAflf\INPUT" t " f J ( A f ) f J ( A f 1 ) f J ( A f 2 ) f J ( A f 3 ) f J ( A f 4 ) 182 IFJ(Af 1 >::=390RJ(Af 1 ) <0THEN189 :l 84 IF J ( A f 2 ) :■ 390R J ( A f 2 ) ::0THEN189 1S6 IFJCAr3>>20RJ-0THEN200\A=A+l\IFA<100THEN180 195 A=A-1 200 A^==A-1 20!=. INPUT "SET PRINTER FOR LIST OF ENTRIES ? 210 '"JOURNAL ENTRIES MONTH =l"f%3IfMfl 220 F0RB==1T027\! " === " f \NEXT\! " "\! " " 230 '"ENTRY $ AMOUNT DEBIT CREDIT 240 F0RB=1T060\! ' == " t\NEXT\ i " «\i • • 250 F0RB=0T0A\Tl=J(Bf 1)\G0SUB1200\T2=T1\T1=J(B»2)\G0SUB1200 260 iX5IfBHf" " f/:$10F2»J(B»0)» • " f T$ ( T2-1 r T2 ) f " ", 265 !T$(Tl-10fTl)»/16IfJ(Bf3)f%12IfJ(B»4) 270 NEXT\C=:-^0 280 !'0 ENDS PROGRAM AND KILLS ALL ENTRIES" 290 ! '1-100 CORRECTS AN ENTRY' 300 INPUT"OVER 100 ENTERS THE ENTRIES INTO THE FILE ? " f B\IFB=OTHENEND 310 IFB:: 100THEN400\C=-1\D = B-1\GOT0330 320 INPUT1"IINTRY NUMBER ?"»D\D = D-1 330 IFD<0nRD>ATHEN320 340 rNPUT'$f DEBITfCREfDEPTfREF ? " » J ( D f ) f J ( D f 1 ) f J ( D f 2 ) f J ( D f 3 ) f J ( D f 4 ) 350 IFJ(Df IXOGRJCDf 1 ) >39THEN360 352 IFJ(Df2)<00RJ(Df2) >39THEN360 354 IF J ( D f 3 ) <00R J ( D f 3 ) := 2THEN360\G0T0280 360 '"CORRECTION REJECTED" \G0T0340 400 IFO0THEN205 410 F0RB=0T0A\E=J(Bf3)\F0RC=lT02\D=J(BfC)\IFC=2THENJ(Bf0)=0-J(Bf0) 420 IFD>19THEN430\B(D)=B(D)+J(B»0)\G0T0440 430 D=D-20\I(EfDfM)=I(EfDfM)+J(BfO)\B(19)=B(19)fJ(BfO) 440 NEXT\NEXT\G0SUB1000\G0SUB1300\ ! " "\!F$ »" UPDATED"\END 1000 INPUT"FILE t " f F$\OPEN*0 f F$\RETURN 1100 F0RA=0T019\READ10fB(A)\NEXT 1110 F0RA==0T02\F0RB==0T019\F0RC = 0T011 1 120 READtOf I (Af Bf C)\NEXT\NEXT\NEXT\CLOSE*0\RETURN 1200 Tl==(Tlfl)*ll\RETURN 1300 F0RA=0T019\URITE*0»B(A)\NEXT 1310 F0RA=0T02\F0RB=0T019\F0RC=0T011 1320 URITE=fOf I (Af BfC)\NEXT\NEXT\NEXT\CLOSE*0\RETURN READY Listing 3: ENTRY! , a program enabling the user to enter business trans- actions into the computer. tains ten sectors or blocks, with 256 bytes of (data on each sector. Every numerical varia- ble written out to (disks using the stan(dar(d North Star Basic requires five bytes. There- fore, each (data file is sub(divi(de(d as follows; Balance sheet items = 20 X 5 bytes Income items = 20 X 3 sub(departments X 12 months X 5 bytes 100 -3600 = 3700 The size of a (data file is 15 blocks (3700 (di- vi(de(d by 256). Listing 1 shows the first pro- gram of the system (LIST1 ). Listing 2 shows the output of LIST1. This program merely shows the co(des (numerical between an(d 39) use(d for each account an(d also allows us to erase all (data from a given file name. A 1 5 block (data file is create(d (using the North Star (disk operating system comman(ds: CR JJR76 15,TY JJR76 3) tokeep trackof the JJR Company for the year 1976. The company was forme(d in December of 1976 an(d has very limite(d transactions. These are entere(d into the accounting system via pro- gram ENTRY1 (shown in listing 3). Listing 4 (details the entry of these transactions which is as follows: 1. Start business by purchasing 1000 shares of stock for $1000. 2. Buy $500 worth of machinery for cash. 3. Obtain a $250 piece of equipment for cash. 4. Purchase raw stock for $50. ENTRY1, like the rest of the system's up- (date programs, always asks for a (data file at the beginning an(d a (date file at the en(d of FILE : JJR76 MONTH : 12 input: t.AMOUNTf DEBIT ACC*, Of Of Of Of ENDS INPUT ENTRY * 1 -'' lOOOfOf 18f Of 1 ENTRY I 2 ? 500f6f0f0f2 ENTRY * 3 ? 200f7f0f0f3 ENTRY * 4 ? 50f8f0f0f4 ENTRY \ 5 ? OfOfOOfOfO SET PRINTER FOR LIST OF ENTRIES ? CREDIT ACCtf DEPTtf REF* Listing 4: A sample run of ENTR Yh The amounts and transaction codes (see listing 2) indicate that the company sold WOO shares of stock for $7000, bought $500 worth of machinery for cash, ob- tained a $250 piece of equipment for cash, and purchased raw stock for $50, JOURNAL ENTRIES MONTH =1 12 ENTRY $ AMOUNT 1 $1000.00 CASH 2 $500.00 MACHINERY 3 $200.00 EQUIPMENT 4 $50.00 RAU STOCK ENDS PROGRAM AND KILLS ALL ENTRIES 1-100 CORRECTS AN ENTRY OVER 100 ENTERS THE ENTRIES INTO THE FILE FILE : JJR76 JJR76 UPDATED READY CREDIT STOCK $1PAR CASH CASH CASH DEFT REFERENCE September 1980 © BYTE Publications Inc 329 lA L^ilfAAy^--' C. ASSETS ;IB L$(45f77) = " EQUITY 20T$( 1. 55)::^ "CASH ;30T$( 56f 110> = "PLANT ^OT^dllflA:';)^" PAYABLES 'oOT$ (166 f ;.>20 ) --= -LT LOANS TELEPHONE TRANSFORT. SALARIES OTHER OTHER PUBLICATION OTHER » Y ( n ) 10 riIMB(2f 19) fT$(440) f Yd ) fT<2f6) f U(lr4) fL(l f 16) fL$(77) Lfi LINE80 L. ASSETS C. LIAB. L. LIAB. TOT. ASSETS TOT. LIAgEO" SECURITIES RECEIUABLESINUENTORY MACHINERY EQUIPMENT RAW STOCK TAXS PAY. LOANS PAY. OTHER PAY. DEBENTURES NOTES OTHER LT STOCK *1PARR. EARNINGS 60T$(221 »275)="SERV. FEES ROYALTIES ASSETS SOLDSOFTUARE OTHER SALES 70T$(27<')»330)-"INL(Bf A)THEN230 220 ' • ■ f \G0T0400 230 IFIOO:: L(Bf A)THEN260 240 T3:=L(B»A) -100\T1.= T3\G0SUB1200 250 iL$(Tl~10fTl)f' •f%9F2»T(0»T3> »T(1 fT3) » %8F2 » T ( 2 » T3 ) r\G0T0400 260 T3=L(Bf A)\T1=T3\G0SUB1200 270 IT$(T1 -lOfTl) f ■ ■ f%9F2fB(0f T3) fBdfT3) f/i8F2fB(2fT3)f 400 IFB=1THEN410\ > • = ■f\G0T0420 410 .' ■ ■ 420 NEXT\NEXT\! ■ "XEND 1000 INPUT -FILE : ' f F$\OPEN*0 f F$\RETURN 1 100 F0RA = 0T019\READ*0f B(Df A)\NEXT\CLOSE*0\RETURN .1200 T1 = (T1 + 1)*11\RETURN 2000 DATAOdOd r 11 f 2 f 1 2 f 3 d3 f 4 f 102 f 100 f 200 f 200 f 1 4 f 200 f 1 5 f 200 f 16 2002 DATASf 17f6f 103f7f200f 8f 18f9f 19f 101 f 104 f 200 f 200 f 105 f 106 4000 INPUT -GIVE FILE TO BE TRANSFERED -? 'fF* 4010 0PEN*0fF$\F0RA=--0T019\READ*0»B(0f A)\NEXT\CLOSE*0 4020 INPUT'GIVE FILE TO RECEIVE DATA ? "fF* 4030 0PEN*0fF$\F0RA=0T019\URITE*0fB(0f A)fNOENDMARK\NEXT 4035 CLOSE*0\RETURN READY Listing 5: BALI, a program that calculates a year end balance sheet. The program is capable of transferring the previous year's records to the current year. TO TRANSFER YEAR TO YEAR ?0 rSIUE FILE TO BE TRANSFERED ? JJR76 GIVE FILE TO RECEIVE DATA ? JJR77 FILE : JJR76 WHAT YEAR UAS THAT ? 1976 FILE : JJR76 WHAT YEAR UAS THAT ? 1976 DATE ? 12/31/76 GET PRINTER READY ? the program. This makes It possbile to save the original file and to produce a new file, which is the original plus any updates. In the example, only one file (JJ R76) is used. Since the transactions shown were the only transactions for the year, it is now pos- sible to run a year end balance sheet. Pro- gram BALI (listing 5) is executed. Listing 6 shows a sample run of the program. BALI first asks if any of the balance sheet items are to be transferred to a new file. This is important because all of 1976's year-end assets, liabilities and equity balances must be transferred to the new year, 1977. There- fore, the user should instruct the program to transfer 1976 balance sheet items (file JJR76)to1977 (file JJR77). The balance sheet program also allows for comparisons to be made and asks for two files to be compared. Since this is JJR's first year of operation, we are forced to compare 1976 to 1976. The balance sheet is now produced. Note that the balance sheet is printed by lines 200 to 420 of the program. A program- ming trick has been used to shorten the length of the actual program. As the ex- ample shows, the balance sheet is com- posed of 17 lines with two entries per line, or 34 total entries. There are 20 individual items, seven totals and seven blank items. Array L(1,16) determines which items appear on each line. An L(1,16) value of to 19 refers to a particular account, 100 to 106 is linked to a total, and 200 is used to generate blanks. Lines 2000 and 2002 show the values of L(1,16). I point this out because most of the financial statements were produced using this method. During 1977 our small business has expanded by hiring a local salesperson. However, sales do not take place until November, and our proprietor wants to seg- regate the revenue generated by himself from the sales brought in by the sales- Listing 6: A sample run of BALI. 330 September 1980 © BYTE Publications Inc BALANCE SHEET AS OF 12/31/76 1976 1976 CASH 250 00 250 00 .00 == PAYABLES SECURITIES »00 .00 .00 := TAXS PAY. RECEIVABLES .00 .00 .00 := LOANS PAY. INVENTORY .00 .00 .00 = OTHER PAY. OTHER .00 .00 .00 :^ C. LIAB. C. ASSETS 250 .00 250 .00 .00 - DEBENTURES LT LOANS NOTES PLANT .00 .00 .00 := OTHER LT MACHINERY 500 .00 500 .00 .00 ;= L. LIAB. EQUIPMENT 200 .00 200 .00 .00 = RAW STOCK 50 .00 50 .00 .00 = STOCK $1PAR OTHER .00 .00 .00 ;= R. EARNINGS L. ASSETS 750 .00 750 .00 .00 u= EQUITY TOT. ASSETS 1000 .00 1000 ,00 .00 - TOT. LIA8E READY -1000.00 -1000.00 DIFF 00 .00 .00 00 .00 .00 00 .00 .00 00 .00 .00 00 .00 .00 00 .00 .00 00 .00 .00 00 .00 .00 00 .00 .00 00 .00 .00 00 -1000.00 .00 00 .00 .00 00 -1000.00 .00 .00 10 riIMB(2r.L9rll) too ! "USE BUDGET F-ILES ONLY '? " r XGOSUBIOOOXGOSUB 1 1 00 .110 '■ TO ADD TO EXISTING BUDGETS" 120 }'l TO G* 'rBrCrD 1A2 IFB<00RB>2THEN300 lAA ifd12THEN300 148 IFC<10RC>12THEN300 L50 INPUT"ACCOUNTf AMOUNT ($.01 RETURNS TO START) -? "rErF 155 E-E~20 160 JFF^ . 01 THEN 1 1 0\ IFE 1 9THEN300 .170 F0RG-=:CT0D\IFA=^0THEN1*?0 180 B(BfEfrr-l)-=:F\G0T0200 190 B ( B f E r G- 1 ) -F f B ( B r E r G~ 1 ) 200 NEXTXGOTDISO 300 '"LAST ENTRY INCORRECT "XGOTC) 1 1 1000 INPUT "FILE : • r F$\OPEN*0 r F$\RETURN I 100 F0RA = 0T019\READ*0»B\NEXT 1110 FORA =0T02\F0RB-=:0T019\F0RC = 0T0 1 1 1120 READ:fOfB(AfBfC)\NEXT\NEXT\NEXT\CLOSE*0\RETURN 130 F0RA-.0TC)19\WRITE*0rZ9\NEXT rilO F0RA=^0TC)2\F0RB=0T019\F0RC = 0T011 1320 URIT£-*OfBCAfBfC)\NEXT\NEXT\NEXT\C;LOSE*0\RETURN rJEADY Listing 7: BUD-INI, a program that generates budgets and enables the user to keep separate records of, for instance^ the sales generated by each sales- person in the organization. FILE : JJR77 MONTH : 11 input: $AMOUNTf DEBIT ACC*f CREDIT ACC* r DEPT*r REF* Of Of Of Or ENDS INPUT ENTRY i 1 '? 500f2f21r0fl=j ENTRY t 2 -? OfOfOfOfO SET PRINTER FOR LIST OF ENTRIES ? JOURNAL ENTRIES MONTH * 11 LOAD BUD-IN 1 READY RUN USE BUDGET FILES ONLY ? FILE : BUD TO ADD TO EXISTING BUDGETS 1 TO 020\G0SUB1200\!T$(Tl-10fTl) f ' '? 190 F0RF=0T011\'%8F2f I(AfEfF) f\I(AfEfl2)=I(AfEfl2)+I(AfEfF) 195 IFA=3THEN205 200 I ( 3 f E f F ) = I ( 3 f E f F ) + I( A f E f F ) 205 T(AfBfF)=T(AfBfF)+I %9F2 f T ( A f 3 f 1 2 ) 247 F0RF=1T033\! ' '\NEXT 250 NEXTAXEND 1000 INPUT'FILE \ ' f F$\OPEN*0 f F$\RETURN 1100 F0RA=0T019\READ*0fB(A)\NEXT 1110 F0RA=0T02\F0RB=0T019\F0RC=0T01 1 1120 READIOf I » W ( 1 » 2 ) » 0* ( 4 4 ) , I ( 3 . 1 9 » 7 ) 12 [r$(lr33)-'AiiMINISr. LOCAL SALEISNAT , SALES ' 15 LINE80 17 7»='AcrRJt»i -y AOT»( 1p Sr,)- "SFRU. fees ROYALTIES ASSETS SOLDSOFTUARE OTHER SALES' 70Ti( 56.110) = "INVENT0RY ASSETS SOLntiEFRECI AT. OTHER OTHER (JOT»( 1 11.165)= 'RENT ELECTRIC GAS TELEPHONE PUBLICATION" VOT$( lAAr220) ^"SUPPLIES POSTAGE TRANSPOR I . SALARIES OTHER 72 INPUT-MONTH '?',M\M=M-1 94 FORAl = 1 r03\& = Al*3\!Zi(£<-2f&). • "f 95 GOSIJ&1000\GOSUfcllOO\A^Al 'M E;-^ A + 4\F0RB-0T02\F0RC-0r019\F0RP=0T0M 78 I( &. C .E ) =^ I ( P »C »E ) + R ( K ,C f [D 100 irM = riTHf:NI (&rC.A)=R(E<,CfD) 102 NEXT[i\NEXTC\NEXTH\NEXTAl 106 P0RA-()T045T)eP4\F(JR&^0T02\F0RC = 0T019 108 I(F{,C:.A) = ICH.C»Af2) -I(&»CpA+1) 110 NLXTC\NEXT&\NEXTA 11-.3 INPUT" A DEPARTMENT #f SAME ♦ OR 0»3 ' •»AlfA2 120 F0RA-0T02\REAtiW(0.A)fU(l,A)\NEXT 124 [iATA0.4r5»9fl0fl9 12A 0«(1 f44)=r:«T0TAL SALESCOST OF GS OTHER EXP. -PROF. /LOSS" 130 F0RA=A1T0A2 132 '"BUHGET STATEMENT "N IFA=3THEN138 134 T1^A\G0SUEi1200\!D»(T1-10fT1 )»• DEPARTMENT" \G0T0140 138 > "TOTAL OF ALL DEPARTMENTS" 140 'TAB(2A)»'M0NTH ♦■»%3I»M+l» ITAB(55)»' YEAR TO DATE* 141 142 ' ' =•= = = = = = = = = = = = = = = = = = = = = = = = = = 143 1 •=============^=============- 144 ""ITEMS VAR. ACT. BUD L.Y, 146 !• ACT. BUD. L . Y . ' \G0SUB1500 170 F0RB=0T02\C=U(0»B)\D=U(lfB)\F0RE=CT0D ISO T1=E \G0SUB1200\?T»(T1-10fT1)»' 'r 190 F0RF=0T07\!Z8F2»I+I(A,EfF) 210 NEXTF\' "■\NEXTE\Tl=B\G0SUB1200\G0SUB1500 215 !0«(Tl-10fTl) . • •» 220 F0RF=0T07\!Z8F2fT(A»B»F)»\NEXTF\! " " 230 ! ••\F0RF=0T07\T(A,3fF)=T(A,3»F)+T(A,B»F)\NEXT 238 NEXTB\! " " 240 !0»(34r44)»" ■r\F0RF=0T07 245 !XaF2fT(A.3»F)f\NEXT\' ■• 247 F0RF=1T033\! • "NNEXT 250 NEXTANEND 1000 INPUT'FILE : " »F«\OPEN#OfF$\RETURN 1100 F0RA=0T019\READ#0»B\NEXT 1110 F0RA=0T02\F0RB=0T019\F0RC=0T011 1120 REA»#OfR^ x.-'t / <' /^^" /'■^ yk^"" ENTRYl 22 10 2 ENTRY2 32 10 2 ENTRY3 42 10 2 LlSTl 4 6 2 LIST2 10 6 2 LIST3 16 6 2 BALI 52 10 2 BAL2 62 10 2 BAL3 72 10 2 JJR76 82 15 3 JJR77 97 15 3 INC0ME1 112 10 2 INC0ME2 122 10 2 INC0ME3 132 10 2 BUD1 142 10 2 BUD2 152 10 2 BUD3 162 10 2 BUD 172 15 3 BUD-IN1 187 4 2 BUD-IM2 191 4 2 BUD-IN3 195 4 2 Listing Ma: A sample run of BUD 1, showing a breakdown of activities for November 1977. ACT stands for actual, BUD for budgeted amounts, L Y. for last year, and VAR for variance. VAR indicates the difference between the budgeted amount and the actual amount taken in or paid out. L Y. in- dicates the amounts for the previous November and is included for reference only. Table 7: Table of con- tents for the floppy disk showing the locations of all programs used in this accounting system. Listing 14a shows the November results for local sales, and listing 14b shows the December results. A listing of the table of contents for the disk containing all of the accounting information is shown in listing 15. The data shown consists of file name, starting block, size in blocks and type (2 = program and 3 = data). The file structure described earlier is fairly simple. Therefore, it is easy to add more programs to the system. The pro- grams can calculate salaries, depreciation and accounts receivable, and enter this infor- mation directly into the data files. The account titles used in the programs are generally found in lines 20 to 90 and can be modified for other usages. The number of accounts can be easily expanded within the current 24 K programmable memory space by limiting the income statement sub- divisions or by eliminating the monthly history. Quarterly type reports can also be added. If you plan to enter these programs into your system, start with program LIST1. Most of the other programs can be formed by editing this particular program." MONTH '12 ACT FILE : JJR77 BUD FILE : BUD L-Y FILE : JJR7A A DEPARTMENT ♦, SAME # OR 0,3 T 1,1 BUDGET STATEMENT LOCAL SALES DEPARTMENT MONTH ♦ 12 YEAR TO DATE ITEMS UAR. ACT. fiUD L.Y. ^;ar. ACT. BUD, L.Y. ■: = = -- = ==:: = = -: :- = -r= = -3r = :=-.= ■= = =:-. = = = == = = = .= = = = = _= : GERW. FEES .00 .00 .00 .00 .00 .00 .00 .00 ROYALTIES .00 .00 .00 .00 .00 .00 .00 .00 ASSETS SOLD .00 .00 .00 .00 .00 .00 .00 .00 SOFTWARE 110.00 -200.00 -90.00 .00 20.00 -200.00 - 180.00 .00 OTHER SALES .00 .00 .00 .00 .00 .00 .00 .00 TOTAL SALES 110.00 -200.00 -90.00 .00 20.00 -200.00 - 180.00 .00 INVENTORY -35.00 50.00 15.00 .00 -20.00 50.00 30.00 .00 ASSETS SOLD .00 .00 .00 .00 .00 .00 .00 .00 DEPRECIAT. .00 .00 ..00 .00 .00 .00 .00 .00 OTHER .00 .00 .00 .00 .00 .00 .00 .00 OTHER .00 .00 .00 .00 .00 .00 .00 .00 = =:=.= ;=:='=;;= = ;= = = ;=-=-=;= = = = --■=:=■= = = : = = = = ^;= = = = = = = = :=.■= ======== ========== COST OF GS -35.00 50.00 15.00 .00 -20.00 50.00 30.00 .00 RENT .00 .00 .00 .00 .00 .00 .00 .00 L'LECTRIC .00 .00 .00 .00 .00 .00 .00 .00 (3AS .00 .00 .00 .00 .00 .00 .00 .00 TELEPHONE .00 .00 .00 .00 .00 .00 .00 .00 PUBLICATION .00 .00 .00 .00 .00 .00 .00 .00 fSUFPLIES .00 .00 .00 .00 .00 .00 .00 .00 POSTAGE .00 .00 .00 .00 .00 .00 .00 .00 TRANSPORT . .00 .00 .00 .00 .00 .00 .00 .00 SALARIES -60.00 100.00 40.00 .00 -20.00 100.00 80.00 .00 OTHER .00 .00 .00 .00 .00 .00 .00 .00 OTHER EXP. -60.00 100.00 4 0.00 .00 -20.00 100.00 80.00 .00 -PROF. /LOSS 15.00 -50.00 -35.00 .00 -20.00 -50.00 -70.00 .00 Listing Mb: A similar breakdown for December 1977. September 1980 © BYTE Publications Inc 335 Whst^New? PERIPHERALS 3 Disk Controller from Shugart A microprocessor-based disk con- troller with on-board data separator logic capable of controlling up to four Winchester hard- or floppy-disk drives is available from Shugart, 435 Oakmead Pky, Sunnyvale CA 94086, (408) 733-0100. The SA1400 features automatic copying of disks, sector in- terleaving, error correction code autonomous to the microprocessor, and optional microdiagnostics. Data transfer between the controller and the host microprocessor is improved by sector buffering. The SA1400 is based on a bit- slice microprocessor and works with Shugart SAIOOO 8-inch and SA4000 14-inch Winchester drives and SA800/850 8-inch floppy-disk drives. Other functions include overlapped seek operations, integral data separators, automatic switching of head and cylinder, and optional track formats. Write precompensation is also included on the board. The Shugart standard floppy-disk protocol and either of the SAIOOO or SA4000 fixed-disk protocols are used for the interface to the drive. A general-purpose interface is used to transfer commands and data between the host processor and the controller. In original equipment manufacturer's quan- tities, the SA1400 is $1125. Circle 539 on inquiry card. Drum-Type Graphics Plotter Strobe Inc has introduced a drum-type graphics plotter with a 0.004-inch step size, and a 21.6 by 28 cm (8.5 by 11 in) paper capacity. The interactve digitizing mode allows the user to enter directly into the host computer X,Y coordinate data corresponding to pen location. The Model 100 plotter is controlled by the computer through two parallel output ports and one parallel input port. Hard- ware interfaces and software drivers are available for the Apple II, TRS-80, PET, and S-100 machines. An optional plot software package, providing vector generation and alphanumerics, that runs with most versions of BASIC and FORTRAN is also available. The price of the Model 100 plotter is $680. For details, contact Strobe Inc, 897-5A Independence Ave, Mountain View CA 94043, (415) 969-5130. Circle 540 on inquiry card. Ectype Floppy Disks from Syncom The Ectype 8- and 5-inch floppy disks have a wear life exceeding 10 million passes for both hard- and soft-sector operations. The disks are 100% cer- tified, and are made for IBM and non- IBM equipment with other formats available. Syncom also manufactures Ectype MC/ST magnetic cards and Ectype 3348-70 Data Modules. For more information, contact Bozell & Jacobs Public Relations, Butler Sq, 100 N 6th St, Minneapolis MN 55403, (612) 371-5500. Circie 541 on inquiry card. DC lOOA Tape Cartridge Drive The Moya Corporation, located at 6311 DeSoto Ave, Unit H, Woodland Hills CA 91367, (213) 533-5993, has in- troduced the MicroDrive/OEM series of tape drives which offer up to 1.344 megabytes of storage in a package that measures 467 cubic cm (28.5 cubic inches). The transport is available with the mechanism-only board or the minimum-electronics board. Both models include a maximum data capacity of 1 .344 megabytes, a transfer rate of 48 K bytes per second, read/write speed of 30 ips (inches per second), and search/rewind speed of 90 ips. The mechanism-only board contains the circuitry required to interface the transport mechanism. The minimum-electronics board provides a switching power amplifier to drive the motor, a digital interface on control and status lines, a write amplifier, and a read preamplifier. The units are $99 in original equipment manufacturer's (OEM) quantities. Circle 542 on inquiry card. Where Do Neiv 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 judgement 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 occa- sional priority modifications. While we would not knowingly print untrue or inac- curate data, or data from unreliable companies, our capacity to evaluate the pro- ducts and companies appearing in the "What's New?" feature is necessarily limited. We therefore cannot be responsible for product quality or company performance. 336 September 1980 © BYTE Publications Inc Wtl9tl3N6W? PERIPHERALS Vector Graphic's MP Printer The Vector Graphic MP is a 5-by-7 dot-matrix, software-driven printer that can print at a speed of 150 cps (characters per second). The price of the MP is under $1000 from Vector Graphic Inc, 31364 Via Colinas, Westlake Village CA 91361, (213) 991-2302. Circle 543 on inquiry card. LY^DCO^^'•K%"H°mTEM t POW£R CARHJtTR m (gSUEMTROL SYSTEMS INC. ^ -— •"-^— -- • Direct-Connect Modem for the TRS-80 Emtrol Systems Inc, 1262 Loop Rd, Lancaster PA 17604, (717) 392-2105, has introduced Lynx, a direct-connect telephone modem for the TRS-80. Lynx connects with the TRS-80 keyboard and the telephone line — no acoustic coupler is used. It includes originate and answer capability, and is programmable for word length, parity, number of stop bits and full- or half-duplex. The minimum requirements are a TRS-80 Level I or II with at least 4 K bytes of programmable memory. The Lynx is priced at $239.95. Circle 544 on inquiry card. Coosol's Printer Kits Coosol has announced the availability of its 40-column friction-feed and 80-column tractor-feed dot-matrix im- pact printers in kit or assembled-and- tested forms. The units are microprocessor-controlled and program- mable with thirty-two system-level soft- ware commands. They feature graphics dot-plotting mode, ninety-six ASCII (American Standard Code for Informa- tion Interchange) characters with upper- case and lowercase, nine software- selectable sizes, reverse-font printing capability, parallel and serial interfaces, data rates from 110 to 9600 bps (bits per second), and adjustable tractor width for paper size selection. Prices for kits are $295 for the 40-column and $455 for the 80-column printer. Assembled and tested impact printers are $325 for the 40-column and $485 for the 80-column, both without enclosures. For further in- formation, contact Coosol Inc, 1585-200 Adams Ave, Costa Mesa CA 92626, (714) 545-2216. Circle 545 on inquiry card. Music Synthesizer for the H-8 from Heath The Heath Company has introduced a music synthesizer system for the H-8 computer. The HA-8-2 music synthesizer system includes a circuit board and soft- ware. The software allows the user to enter any song into the system from conventional sheet music. The syn- thesizer board, which connects to any stereo system with two shielded cables, produces a 27.5 to 6600 Hz frequency response with up to nine harmonics. An H-8 with at least 24 K bytes of memory, a floppy-disk drive, and video terminal are required. The HA-8-2 is priced at $159 from Heath Company, Benton Harbor MI 49022, (616) 982-3210. Circle 546 on inquiry card. Storage Control Unit for the TI990 Bus The ISC 4000 supports up to four 14- or 29-megabyte Shugart Winchester disk drives. The unit will also support floppy-disk or high-density tape backup devices. Compatibility with Texas In- struments' TI990 software is maintained by emulating existing TILINE bus devices. A complete 29-megabyte system, including a floppy disk, sells for $7000 from Data Management Labs, 2148 Bering Dr, San Jose CA 95131, (408) 946-9424. Circle 547 on inquiry card. September 1980 © BYTE Publications Inc 337 Wti8t% New? PERIPHERALS Speech Recognition Unit The Heuristics 7000 speech recognition unit, which sells for approximately $3000, will interface with all RS-232 ter- minals. The 7000 enables users to enter information into their computers direct- ly and with few errors. By eliminating the need for hand entry, busy businesspeople and the handicapped will benefit. The unit can recognize up to sixty-four words or phrases, each up to 3 seconds in length, and it is compatible with all common programming languages. It enables computers to take keyboard or voice input, or both simultaneously. The 7000 comes with a noise-cancelling headset microphone. Contact Heuristics, 1285 Hammerwood Ave, Sunnyvale CA 94086, (408) 734-8532. Circle 548 on inquiry card. Interactive Video The Cavri III computer/video player integrator enables users to index and later access videotape frames or segments or to interact with videotaped materials. In addition to integrating computer-aided instruction with videotape, the system is useful for storage and retrieval of text and audio- visual information. The system also allows a user to control all remote func- tions of the video machine from the computer keyboard or from within a program. Access time to a desired point on a video cassette is less than 5 seconds. The average time required to find randomly distributed segments of tape on a 30-minute cassette is about 45 seconds. Search accuracy is ± 7 frames. The Cavri III consists of an Apple I/O (input/output) board, cables and con- nectors, systems software in Applesoft BASIC on disk, and a user's manual. It is available for video cassette recorders that carry a control pulse or that inter- face with manufacturers' search units. Users can convert already made videotapes, produce new tapes, or ar- range to have Cavri produce materials. For information, contact Cavri Systems Inc, 26 Trumbull St, New Haven CT 06511, (203) 562-9873. Circle 549 on inquiry card. Floating-Point Board for the Apple Increased speed is now available for the Apple 11. The Computer Station Am9511 fast floating-point processor board plugs into the Apple II and relieves it of the task of doing transcendental functions in software. In- stead, it uses a version of the standard floating-point BASIC, called Applefast, that allows the user to run existing pro- grams without modifications: Taking 5000 square roots normally takes 250 seconds running Applesoft, but with Applefast it takes 15 seconds. Details can be obtained from Computer Station, 12 Crossroads, Granite City IL 62040, (618) 452-1860. Circle 550 on inquiry card. Reduce the Cost of Memory for the PET ThePH-OOl 2114 programmable memory adapter for the 2001-8 PET allows the use of lower-cost 2114 pro- grammable memory integrated circuits to replace one to eight of the 6550's 1 K by 4 circuits used in the 8 K-byte PET. The board alone is $8.95, and the entire unassembled kit is $13.95, or $24.95 assembled. Contact Optimized Data Systems, POB 595, Placentia CA 92670, (714) 996-3201. Circle 551 on inquiry card. MSC-8100 Features Hard- and Floppy-Disk Storage The MSC-8100 system incorporates an intelligent controller/formatter with a universal IEEE-488 bus protocol, a Win- chester technology hard-disk drive with a 19.1-megabyte capacity, and a backup floppy-disk drive with a capacity of 1.6 megabytes per disk. The MSC-8100 is useful for word-processing and small- business applications. The average ac- cess time of the hard-disk drive is below 30 ms. The controller features a full- sector data buffer, error detection and correction, error recovery including automatic retry, automatic position verification, automatic seek to alternate track, parallel or serial interrupt, relative sector addressing, programmable sector interleaving, implied seeks, and more. Self-testing diagnostics are also provided. The MSC-8100 is priced at $9250. For information, contact Microcomputer Systems Corporation, 432 Lakeside Dr, Sunnyvale CA 94086, (408) 733-4200. Circle 552 on inquiry card. 338 September 1980 © BYTE Publications Inc Wh8«^ New? MISCELLANEOUS Pensee Pascal Computer Computer Interface Technology's Pensee system is a stack-oriented, 16-bit computer with a dual floppy-disk sub- system capable of storing up to 2 megabytes. It features 64 K bytes of pro- grammable memory; floating-point hardware; floppy-disk controller; 8-inch single- or double-sided, single- or double-density floppy-disk drives; two serial RS-232 asynchronous/synchronous ports; two unidirectional 8-bit parallel ports; and self -test diagnostics. Pensee utilizes the UCSD Pascal operating system version III.O, which includes the Pascal compiler, BASIC compiler, file manager, screen-oriented editor, and debugger. Some UCSD language exten- sions are also included. Prices range from $3500 to $9000, depending on peripheral subsystems. Obtain informa- tion from Computer Interface Technology, 201 W Dyer Rd, Santa Ana CA 92707, (714) 979-9920. Circle 553 on inquiry card. Peelings Peelings is devoted exclusively to reviews of software for the Apple II and Apple II Plus microcomputers. Each bimonthly issue contains reviews of twelve to fifteen programs or software packages. Subscriptions are $15 from PeelingSr Ed Burlbaw, 945 Brook Cr, Las Cruces NM 88001, (505) 523-5088. Circle 554 on inquiry card. The Flex-File System The Flex-File is a nonglare vinyl page having pockets on each side to house two 8-inch floppy disks plus a center pocket to store 22 by 28 cm (8.5 by 11 inch) paper, computer printouts, or other documentation. The pages are three-hole punched for storage in stan- dard three-ring binders. Flex-File pages are priced at $8.95 for a package of ten pages and are available from BIS Inc, POB 969, Brentwood TN 37027 Circle 555 on inquiry card. Elementary Math Edu-Disk The Elementary Math Edu-Disk con- tains an arithmetic-readiness test and four interactive lessons designed to teach elementary addition, subtraction, multiplication, and division, in nine skill levels. These lessons use color graphics and a computer-simulated voice to maintain student interest and reinforce basic concepts. The student's scores are maintained on disk and are accessible only through a special teacher's pro- gram. The system is self-demonstrating and is recommended for the student with no prior arithmetic experience, and as a supplement in higher-level remedial situations. The requirements for the pro- gram are an Apple II computer with 48 K bytes of programmable memory with Integer BASIC. The price for the program is $39.95, from Muse Software, 330 N Charles St, Baltimore MD 21201, (301) 659-7212. Circle 556 on inquiry card. Got floppy disk problems? i^Here^s a ne^v four letter word to use: ^^cJt^^'-^ '-^ The wi^rd is KYBE. Because KYBE will ship yi)u the same high peiformance prcKlucts they've huilt tc^r OEM's ior years. CiMisistent quality media that meets the mi^st demanding specificaticms. OEM's won't risk the pertormance oi their system lo less than the best media. Why risk your data either? Especially when the price is ci^iipetitive. Get twi> day shipment cmi any mcKlel floppy disk, data cassette or mag card. Each is hacked hy an unconditional 90 day warranty and inventoried for fast delivery. Call toll free (800)225-8715. Dealer inquiries invited KYBE Dennison KYBE Corporation 132 Calvary Street. Waltham. Mass. 02154 Tel. (617) 899-0012: Telex 94-0179 Outside Mass. call toll free (800) 225-8715 Offices & representatives worldvyide K V /S e Circle 258 on inquiry card. September 1980 © BYTE Publications Inc 339 Wbst^NewF MISCELLANEOUS Dust Covers for Computer Terminals I # mM-. ■•'fV^^ These dust covers are designed to pro- tect video terminals, printers, and keyboards from dust and dirt. They are made of heavy-gauge clear plastic that will protect against water damage. The covers are custom made to fit any specific model of computer terminal, keyboard, or printer for all computer systems. When ordering, specify the system being used. The price for a cover for a video terminal including keyboard is $9.95. For a keyboard only, it is $8.95, and for a printer it is $9.95. For details, contact The Computer Ac- cessories Company, 20 Boat Ln, Port Washington NY 11050, (516) 767-0366. Circle 557 on inquiry card. Burst-Error Processor from AMD Advanced Micro Devices (AMD) has announced a general-purpose burst-error processor (BEP). This LSI (large-scale in- tegration) device, the AmZ8065, can detect and allows correction of up to 12-bit burst errors in serial data streams moving at up to 20 million bps (bits per second). The codes implemented in the BEP include 48- and 56-bit polynomials used by IBM and 32- and 35-bit polynomials favored by minicomputer manufacturers. The BEP provides two read modes, normal and high-speed, that determine the correction methodology if an error is found. The AmZ8065 user can select the correction method based on the Chinese Remainder Theorem. This method computes the er- ror location and the correction needed. The BEP employs a reciprocal polynomial that approaches the data stream from the check-bits side. This reduces worst-case correction time to the length of the data stream. The device ac- cepts data as serial bytes which allows a single-phase clock requirement of 2.5 MHz. It operates from a single +5 V supply and comes in a 40-pin integrated circuit. Prices start at $69 each in one hundred-unit lots. Contact Advanced Micro Devices Inc, 901 Thompson PI, Sunnyvale CA 94086, (408) 732-2400. Circle 560 on inquiry card. Accounts Receivable Program for the TRS-80 Radio Shack has an accounts receivable system for use on the TRS-80 Model I. Accounts receivable provides end-of-month billing, statements ready for mailing, automatic customer-record updating, totals for general ledger posting, optional message lines on bill- ing statements, and full accounts receivable analysis including activity status, and more. Reports printed by this system are complete transaction file report, general ledger recap report, com- plete accounts listing, account listing by activity status, accounts receivable analysis by activity status, and posting report. A Model I Level II system with 16 K bytes of programmable memory, plus an expansion interface with at least 16 K bytes of programmable memory, an 80-column printer, and a minimum of two disk drives are required. The ac- counts receivable system is priced at $149.95 from Radio Shack dealers and stores. Circle 558 on inquiry card. Computer/Typewriter Interface The I/O Pak from Rochester Data consists of an array of coils positioned in the same pattern as a typewriter's keyboard, in a unit that fits directly over the keyboard. These coils are wired into an electrical decoding matrix. The I/O Pak is designed to generate hard copy directly from a computer through any electric typewriter with a powered carriage return. No modification to the typewriter is required, and all ad- justments to compensate for different key heights are incorporated in the I/O Pak. Available options include interfaces and software for the TRS-80 Level I and II, the Apple II, and a 6-bit parallel in- terface for general operation with other computers. Centronics-compatible and PET interfaces are also available. The I/O Pak retails for $469; the interface board and power supply required for packaged operation are priced at $145. Contact Rochester Data Inc, 3100 Monroe Ave, Rochester NY 14618, (716) 385-4338. Circle 559 on inquiry card. OKI 4 K Static Programmable-Memory Integrated Circuits OKI Semiconductor, 1333 Lawrence Expy, Suite 401, Santa Clara CA 95051, (408) 984-4840, has introduced the MSM 2114L series of 4 K static pro- grammable memory integrated circuits. The MSM 2114L, MSM 2114L-2, and MSM 2114L-3 are n-channel silicon-gate MOS (metal-oxide semiconductor) cir- cuits that use fully static circuitry which does not require clocks or refreshing. The circuits are interchangeable with all standard 2114L parts and feature TTL- compatible (TTL is transistor-transistor logic) I/O (input/output), and a single +5 V power supply. They feature max- imum access times of 200 ns for the 2114L-2, 300 ns for the 2114L-3, and 450 ns for the 2114L, and maximum power dissipation of 370 mW. Prices are $5.45 for the 2114L, $5.65 for the 2114L-3, and $6.75 for the 2114L-2. These prices are for 100-unit quantities. Circle 561 on inquiry card. 340 September 1980 © BYTE Publications Inc Whst^ Nsw? MISCELLANEOUS Model 460 Paper Tiger features include pin-feed tractor drives. Printer from IDS iroTrpS^Tel^^rdter'^ The Model 460 addition to the IDS tronics each time the power is turned Paper Tiger family of printers produces on, and a full character-set print letter-quality printing at a speed of 160 capability test. A 2 K-byte buffer cps (characters per second). It also pro- allows the Model 460 to accept the con- vides high-resolution graphics capability tents of a 1920-character video screen, and includes proportional character The 460 has a standard RS-232C serial spacing and automatic text justification. interface as well as a Centronics- The Model 460 is a dot-matrix printer compatible parallel interface. Serial that utilizes a horizontal and vertical dot transmission rates from 110 to 9600 bps overlay to achieve letter-quality print- (bits per second) are switch selectable, ing. It can print in 80-, 96- and The Model 460 costs $1295 from Integral 132-column formats. Foreign and custom Data Systems, 14 Tech Cir, Natick MA character sets are optional and up to 01760, (617) 237-7610. four 96-character sets can reside in the 460 at the same time. Paper-handling Circle 562 on inquiry card. Music Synthesizer for the Apple The Juke Box is a music synthesizer designed for any 48 K-byte Apple using Applesoft BASIC. It can produce three simultaneous voices and one channel of white noise. Pitch, rhythm, tempo, at- tenuation, and envelope can be selected and controlled for each voice in- dependently from the other channels. The synthesizer has a five-octave range. Each card has an on-board amplifier capable of directly driving an 8-ohm speaker. As many as six cards can be in- stalled to generate a total of eighteen notes. Multiple boards can create stereophonic, quadraphonic, and polyphonic operation. The devices can be daisy-chained to create more voices per speaker. A graphics music editor is also provided so the music can be seen and heard as it is input and edited. The price for the Juke Box is $129.95. Con- tact American Micro Products Inc, 705 N Bowser, MS 107, Richardson TX 75080, (214) 238-1815. Circle 564 on inquiry card. Acf-ion l?il-»l-»r»r»c private labels are available. The com- /\Spen KlDDOnS p^^^ ^^^^ ^^^ ^ ^^^^ multistrike car- Aspen Ribbons has announced the ad- tridge ribbon and Qume 2 and 3 dition of four cartridge ribbons to its line multistrike ribbons. For additional infor- of ribbon products. Aspen now mation, contact Aspen Ribbons, 1700 N manufactures Hytype I and II ribbons in 55th St, Boulder CO 80301, (303) nylon and carbon. Aspen molds its own 444-4054. cartridges by injection. Colors and Circle 563 on inquiry card. I If you are developing commercial software for a CP/M ' system, you need a keyed file accessing package to create efficient, on-line, interactive systems. Only MICRO 6+™ offers all these advantages: •Guaranteed optimal file accessing performance! •Key access to data files with over 10,000 entries in under one ' second... on floppy disk systems! •No reorganization of index and data files! Before you order the most important com- ponent of your software development tool kit, compare. MICRO B+™ js unmatched by any other product available anywhere. Assembly Language Version. ..$260.00 Specify MICROSOFT "REL'.' Files or CBASIC Compatible BASIC Source Code Version. ..$195.00 Specify MICROSOFT Basic-5 or CBASIC-2 Shipping $2 USA/$5 Foreign AIRUOM 2606 JOHNSON DRIVE COLUMBIA. MO 65201 (314)445-3304 We accept VISA and MASTERCARD 6809 3-100 SINGLE-BOARD COMPUTER Meets IEEE S-100 Standard Uses Motorola's Powerful MC6809CPU 4K/8K/16KROM • 2K RAM ACIA, PIA,8080Simulated I/O RS-232 Handshake • 8 Selectable Baud Rates Manual includes: 11x17" Schematic, Parts List, User Notes, Software Listings & More! »*° *0S-9 Microware's.^ 6809 MULTI-TASKING OPERATING SYSTEM CONFIGURED FOR THE ADS 6809 S.B.C.! • InterruptDrlven Multl Device I/O • Full Memory Management Capability • Complete Array of OS-9 System Software • Much More • OS-9 trademark Microware. Inc. & Motorola WRITE FOR COMPLETE DETAILS 6809 P. C. Board & Manual $69.95 Shipping $1.50 III. Res. Add Sales Tax ACKERMAN DIGITAL SYSTEMS, INC. 110 N. York Rd. • Suite 208 • Elmhurst, Illinois 60126 • (312) 530-8992 Circle 259 on inquiry card. Circle 260 on inquiry card. September 1980 © BYTE Publications Inc 341 Whafs New? MISCELLANEOUS OSI CIP Superboard II Modification Kit The Super-Mod Kit provides a 48-character by 26-line video display and software selection of 300 or 1200 bps (bits per second) for cassette and RS-232 operation. The kit also provides an RS-232 port, start and stop control of the cassette, and doubling of system clock speed. Voice cuing and a listening function can be added. The kit contains all parts and documentation. Among the kit's contents are a regulated multiple-voltage power supply, a pro- grammed monitor PROM (program- mable read-only memory) compatible with all existing Ohio Scientific In- struments' functions and capable of for- matting the video display with screen clear function callable under BASIC or assembly language, and sample pro- grams. The price is $95 from A H Systems Inc, 9710 Cozycroft Ave, Chatsworth CA 91311, (213) 998-0223. Circle 565 on inquiry card. AIM-65 Enclosure This enclosure is designed for the AIM-65 microcomputer. It is made out of high-strength ABS plastic and comes with mounting hardware, wire, and switches. All parts are pre-cut and drilled, and there is room for two addi- tional boards. The color is white with a blue base. The enclosures are $49.95 plus $2.50 for shipping and handling. Contact Don-El Enterprises, 3261 Michigan Ave, Costa Mesa CA 92626, (714) 546-7481. Circle 566 on inquiry card. Modem Microphone from Novation Super Mike was engineered specifi- cally to eliminate data-distorting second harmonics. This Federal Communica- tions Commission (FCC) registered microphone slips into your telephone handset, replacing the existing carbon microphone. The device eliminates the carbon granule packing problems that can cause a difference in reproduction level from telephone to telephone. Priced at $9.95, Super Mike is available from hobby stores, retail electronic outlets, and industrial distributors. For complete information contact Novation, 18664 Oxnard St, Tarzana CA 91356, (213) 996-5060. Circle 567 on inquiry card. The Nobus-Z The Nobus-Z contains a 4 MHz Z80A microprocessor, the CP/M operating system, 64 K bytes of dynamic program- mable memory, dual-density 8-inch floppy-disk drives with 600 K bytes per side, and a 6 K-byte color text and graphics feature. Console configurations range from a keyboard and television set to separate word-processing display ter- minals. A typical 70 K-byte system with 600 K bytes of disk storage costs under $3000. For more information, contact Exo Electronics Company, POB 3571, Culver City CA 90230, (213) 390-6527. Circle 568 on inquiry card. AIM-65 Expansion The Memory-Mate, a 16 to 48 K-byte programmable-memory expansion board offers AIM-65 expansion for develop- ment system and process-control ap- plications. The memory is assignable in 4 K blocks, with each of the blocks posi- tionable anywhere in the system. The board also features full parity check cir- cuitry and includes protection for AIM's 4 K on-board programmable memory. Another feature is programmable write protection in 4 K blocks. Four 8-bit bidirectional, 6522-type I/O (input/out- put) ports are included on the board. In addition, the board includes a program- mable tone generator for audible warn- ings and sockets for up to 4 K PROM (programmable read-only memory). Price of the Memory-Mate with 16 K bytes of storage, connector to AIM, and manual is $475. Write AIM-Mate Series, Forethought Products, 87070 Dukhobar Rd, Eugene OR 97402, (503) ^85-8575. Circle 569 on inquiry card. Floppy Disk Insurance? Micro Lab has instituted a new plan for microcomputer users: Micro Lab Disk Insurance. The policy is being of- fered with the purchase of its Data Fac- tory product line. The package is sold to the user with two locked versions of the master disk. If a master disk becomes damaged during the policy period, the policyholder may return the inoperative copy to Micro Lab for immediate free replacement. Users can switch to the backup master disk without any break in service. In addition, if an update in the program should occur, users will be notified, and the older versions will be revised at no cost. The policy sells for $17.50 per year. The Data Factory, a data-base management system, is offered in Applesoft and other forms. The pro- gram can run with one or two disk drives, but needs 48 K bytes with Applesoft in read-only memory. Infor- mation can be obtained by writing or calling Micro Lab, 811 Stonegate Dr, Highland Park IL 60035, (312) 433-7877. Circle 570 on inquiry card. The PMC-80— Compatible with the TRS-80 Personal Micro Computers Inc, 475 Ellis St, Mountain View CA 94043, (415) 968-1604, is offering a software- and hardware-compatible equivalent of the Radio Shack Model I, Level II TRS-80. The PMC-80 has a cassette tape recorder, 16 K bytes of programmable memory. Level II Microsoft BASIC in- terpreter in ROM (read-only memory), a power supply, computer, and keyboard. The system will display on either a television monitor or on a television set using a built-in VHF channel 3 modulator. All software available for the TRS-80 will operate in the PMC-80. Level II BASIC or SYSTEM cassettes will load in the PMC-80 without volume adjustments. All peripherals designed for the TRS-80 parallel port interface to the PMC-80 through an interface adapter available from the company. The price for the PMC-80, according to the manufacturer, is about $200 less than a comparably equipped TRS-80. Circle 571 on inquiry card. 342 September 1980 © BYTE Publications Inc Wh8t% New? MISCELLANEOUS Multibus-Compatible Multimemory Board A Multibus-compatible memory module that can accommodate industry- standard ROMs (read-only memory), EPROMs (erasable programmable read- only memory), and static programmable-memory integrated cir- cuits in any combination is available from Artec Electronics Inc, 605 Old County Rd, San Carlos CA 94070, (415) 592-2740. The board contains sockets and memory interface logic for up to sixteen twenty-four-pin memory devices. It can contain a maximum of 64 K bytes of EPROMs or 32 K bytes of static programmable-memory circuits. The board can operate with only one socket filled. Memory addresses are in- dependently assigned for each socket with wire-wrap jumpers. Any multiple of 1 K bytes can be addressed within a 64 K-byte address space. Memory access time is wire-wrap selectable. The low- power interface circuitry contains inhibit logic for each of two banks of eight memories. The multimodule board can interface with any 8-bit Multibus- Printer from Matchless The MS-204 printer is compatible with the TRS-80, Apple, PET, or any Centronics-type system. This 132-column, bidirectional, 9-by-7 dot- matrix printer has a printhead life of 100 million characters. Among the features are a print speed of 125 cps (characters per second) and throughput print speed of 63 lines per minute. The adjustable sprocket feed mechanism allows the use of forms from 6.4 to 24 cm wide (2.5 to 9.5 inches), with loading from either the bottom or rear. Uppercase and lower- case characters are provided. The printer provides preprogrammed and program- mable tab postions, and top of form and bottom of form functions. The retail price is $795 from Matchless Systems, 18444 Broadway, Gardena CA 90248, (213) 327-1010. Circle 575 on inquiry card. compatible microcomputer. The price of the board is $175, not including memory circuits. Circle 572 on inquiry card. PDP-11 FORTH This FORTH system runs on any PDP-11 or LSI-11 microprocessor and requires less than 24 K bytes of memory. The floppy disk contains an RT-11 directory with FORTH in Macro-11 source, with extensive com- ments; this source can be assembled and run under RT-11, or under RSX-llM, or stand-alone, with or without EIS. The disk is single-density, but will run on a dual-density drive under RT-11. PDP-11 FORTH implements the FORTH Interest Group (FIG) language model, with full- length names to 31 characters, and ex- tensive compile-time checks. In addition, an editor, a FORTH assembler, and a string package in FORTH source, are in- cluded. The system on disk, the PDP-11 FORTH User's Guide, A FORTH Primer, FORTH Introduction Reprints, an installation manual, and an assembly listing comprise the entire system. The cost is $140 from John S James, POB 348, Berkeley CA 94701, (415) 526-8815. Circle 576 on inquiry card. Desk-Top Calculator with a Voice The Model SP1260-D, a talking calculator from Canon, is expected to be used in general business offices, banks, brokerage houses, schools, hospitals and factories. The unit's speech synthesizer is used when the operator wants to check entries on the roll paper.' The voice feature eliminates the need for two employees to check lists of numbers. The calculator can store up to 128 items of data, including the final result of the input. The SP1260-D incorporates the voice feature, a 12-digit capacity, memory for accumulating results, item counting, decimal point selection, and more, for $399. Contact Canon Calculator Division, Canon USA Inc, 10 Nevada Dr, Lake Success NY 11042. Circle 573 on inquiry card. All-CMOS Single-Board Microcomputer Pacific Cyber/Metrix Inc, 6800 Sierra Ct, Dublin CA 94566, (415) 829-8700, has announced availability of an all- CMOS (complementary metal-oxide semiconduc- tor) single-board microcomputer capable of plugging directly into the Intel-originated Multibus card cage. The PPS-1201 features a CMOS 6100 microprocessor, 4 K bytes of memory that can be configured as any combination of CMOS programmable memory and CMOS EPROM (erasable programmable read-only memory), a program- mable real-time clock, memory expansion controller, three 12-bit-wide parallel ports, and a single serial port. Also included is a transparent 1 K-byte monitor and debugger plus a binary bootstrap for loading on-board programmable memory through the serial port. The 6100 microprocessor employs a binary instruction set identical to that of the Digital Equipment Corporation PDP-8 and VT-78 DECsta- tion minicomputers, so software development can be carried out on any of these machines. The price for the 1201 is $995. Circle 574 on inquiry card. SOFTWARE WANTSO If you are an inventive programmer and could use an extra income, please call: (213)894-9154 \Yc lire interested in ( jiinies iuid Business software. Royalty or (]asli-oiit basis. DATAvSOFT 16606 Schoenborn St. Sepulveda, Ca. 91343 Circle 261 on inquiry card. September 1980 © BYTE Publications Inc 343 WhstlsNew? PUBLICATIONS Report on Personal Computers Covers Trends, Systems, Software, and Vendors Datapro Research Corporation's All About Personal Computers, traces the develop- ment of personal computers, discusses the future of the devices, and outlines how to buy a system. Also featured are reports on fifteen of the top personal computers, plus directories listing vendors of computers, software, peripherals, and publications. All About Personal Computers is available for $25 from Datapro Research Corporation, 1805 Underwood Blvd, Delran NJ 08075, (609) 764-0100. Circle 577 on inquiry card. Report on Voice Processing The technologies of speech recognition and speech synthesis have been im- plemented into computer systems and have been employed in transportation, quality control, auto assembly, bank deposit transfer, and consumer products. In the April 1980 issue of Data Entry Awareness Reports, MIC (Management Information Corporation) discusses the voice-processing state of the art, its applications, and how to use it. This report is available to subscribers of Data Entry Awareness Reports or can be pur- chased separately by check for $15. Contact Voice Processing Report, Management Information Corporation, 140 Barclay Center, Cherry Hill NJ 08034, (609) 428-1020. Circle 578 on inquiry card. A Catalog from Wintek A catalog containing information and specifications on Wintek's Sprint 68 development system/control computer with Wizrd multitasking DOS (disk operating system), macro editor, assembler, C compiler, 12 K BASIC, and 4 K industrial BASIC, is now available. The catalog also discusses alternatives for software development, Wintek's design and educational ser- vices, and cross software products. Con- tact Wintek Corporation, 1801 South St, Lafayette IN 47904, (317) 742-8428. Circle 579 on Inquiry card. Computer Selection Handbook Written specifically for small businesses and consultants, the Com- puter Selection Handbook presents a nontechnical method for selecting com- puter systems. This book concentrates on the practical and business aspects of choosing the right computer for your small business. The Computer Selection Handbook explains how to document small-business computer needs, solicit and evaluate vendor proposals, make the selection decision, and manage the installation and operation of the new system. The handbook is available directly from Decision Resources Cor- poration, 28203 Ridgefern Ct, Rancho Palos Verdes CA 90274, (213) 377-3533, for $35. Circle 580 on inquiry card. BASIC Training for Compucolor Computers BASIC Training for Compucolor Computers, by Joseph J Charles, is intended for beginning users of the Compucolor II computer and is designed to serve as an introduction to Com- pucolor II BASIC. There are over 100 example programs and dozens of exer- cises in the book. The topics covered in- clude the first steps of entering and listing programs, BASIC statements, functions, graphics, random-access files, flow-charting, subroutines, and more. The price of the book is $14.95, and it is available from Joseph J Charles, Dept B, POB 750, Hilton NY 14468, Circle 581 on inquiry card. Back Issues of Dr Dobb's Journal Dr Dobb's Journal of Computer Calisthenics and Orthodontia: Running Light Without Overbite, volumes 1, 2, and 3, are available from Hayden News. Almost everything from all issues of Dr Dobb's Journal for a particular year have been gathered into these volumes. They are priced at $18.95 each from Hayden Book Company, 50 Essex St, Rochelle Park NJ 07662, (201) 843-0550. Circle 582 on inquiry card. Archer Engineer's Notebook Radio Shack has published a hand- book of 415 electronic circuits for elec- tronics hobbyists, experimenters, tech- nicians, and engineers. Applications are included for most of the integrated cir- cuits sold by Radio Shack. Dozens of problem-solving circuits are described. Tips and techniques for beginners are included. The book is divided into two major sections: digital and linear. It was compiled and hand-executed by Forrest M Mims III. The Archer Engineer's Notebook is available from participating Radio Shack stores and dealers for $1.99. Circle 583 on inquiry card. AIM-65 Newsletter from Rockwell A newsletter for owners of AIM-65 microcomputers is available on a subscription basis from the Newsletter Editor, Rockwell International, POB 3669, RC55, Anaheim CA 92803, (714) 632-2321. Interactive responds to readers' questions, publishes articles by users, reports on the activities of AIM-65 users groups, and supplies ar- ticles on novel applications. The cost is $5 for six issues. Circle 584 on inquiry card. BITS Catalog The fall issue of the BITS catalog is available. BITS is a distributor of computer publications located at 25 Rt 101 W, POB 428, Peterborough NH 03458, (603) 924-3356. This catalog features publications from BYTE, Osborne/McGraw-Hill, Scelbi, and others. The catalog is priced at $0.50. Circle 585 on inquiry card. 344 September 1980 © BYTE PublicaHons Inc Whsl^New? PUBLICATIONS Health Planning Publication Hapenney Associates has announced a publication entitled Data Bits. It is writ- ten for health planners, and is designed to coordinate the data and automation efforts of health planners within the 205 health-systems agencies and 51 state health planning and development agencies in the US. It examines technological advances in automated data processing that may affect health planners. Items of interest regarding happenings at the federal level are pro- vided, as well as information regarding current activities of different agencies. Data Bits is published monthly. Subscriptions are available at $60 per year. Single issues are $5 per copy. Con- tact the Assistant to the Editor, POB 1076, Columbia MD 21044, (301) 596-0874. Circle 586 on inquiry card. User Ratings of Computer Systems User Ratings of Computer Systems, from Datapro Research Corporation, 1805 Underwood Blvd, Delran NJ 08075, (609) 764-0100, details the results of a survey of 14,900 computer users that produced 4614 usable responses that provided ratings of 7871 installed sys- tems from sixty-four vendors, along with information on applications, software, languages, problems, and future user plans. The survey covers personal computers, mainframes, minicomputers, and small-business com- puters. The report also includes sum- maries of ratings for various software applications, which languages are most commonly used on different systems and configurations, and how users felt about documentation for systems. Copies are available for $25. Circle 587 on inquiry card. Bulletin on DC-to-DC Power Supplies A data sheet introducing a selection of thirty new 5 and 6 watt, DC-to-DC power supplies is available from Sola Electric, 1717 Busse Rd, Elk Grove Village IL 60007, (312) 439-2800. The low-profile switching converters are designed for printed-circuit board mounting. Specification charts provide basic technical data, operational and physical descriptions. Circle 588 on inquiry card. The MicroShopper Guide to Microcomputers MicroShopper 80: The New Com- puters is a 192-page business and per- sonal guide to microcomputer hardware and software, published by P G I Publishing, a division of The Phoenix Group, 1425 W 12th PI, Tempe A2 85281, (602) 967-1421. This fifth edition features photographs of microcomputer systems, peripherals and accessories, plus industry literature from more than 100 manufacturers representing over 500 products. It is designed for first-time computer users, consultants, dealers, and data-processing profes- sionals. Definitions, explanations, and reviews of equipment are provided. MicroShopper is priced at $9.95 retail or $11 including postage and handling, direct from P G I. Circle 589 on inquiry card. TRS-80 Supply Catalog The TRS-80 DOSHS (Directory of Software, Hardware, and Services) is designed to help users locate software, hardware, and support services for the TRS-80 microcomputer. The catalog contains hundreds of listings for S-100 adapters for the TRS-80, books, color- graphic units, TRS-80 units, consulting services, floppy disks, expansion inter- faces, RS-232 interfaces, light pens, lowercase modification kits, magazines, newsletters, plotters, printers, rentals, repair services, speech synthesizers, and more. It is available for $6 from Pen-Ter Research, 9633 Rosehill Rd, Lenexa KS 66215. Circle 590 on inquiry card. International Directory of Software The International Directory of Soft- ware is a one-volume directory featuring over 3200 independently marketed soft- ware products available from American and European suppliers. Each product is indexed within as many as five categories. Systems and applications software are listed in the directory under a total of 107 categories, including com- munications, compilers, data manage- ment, development aids, systems soft- ware for mainframes, systems software for microprocessors, utilities, account- ing, administration, production and distribution, modeling, and other categories for various specialized ap- plications software. Data on each prod- uct describes its date of origin, installed base, function, terms for purchase or leasing, operational mode, configuration requirements, and the names and ad- dresses of suppliers worldwide. The In- ternational Directory of Software is priced at $140. Contact CUYB Publica- tions Inc, First Federal Bldg, Suite 401, Pottstown PA 19404, (215) 326-5188. Circle 591 on inquiry card. The BOOK: Accessing the TRS-80 ROM, Volume I The BOOK is the first of three volumes on machine- and assembly-language ac- cess to the Level II BASIC ROM (read- only memory) in the TRS-80 Model I microcomputer. This volume details the mathematic subroutines and data for- mats. A fully commented listing of these routines is provided. Included in the book is a memory map of the entire machine that provides descriptions of over 500 memory locations. The BOOK is available at computer stores or from In- siders Software Consultants, POB 2441, Springfield VA 22152, (703) 960-2998, for $14.95 plus postage and handling. Circle 592 on inquiry card. Catalog from OK Machine and Tool Corporation This catalog from OK Machine and Tool Corporation, 3455 Conner St, Bronx NY 10475, (212) 994-6600, features numerous wire-wrap tools and supplies, controllers, tape readers, cir- cuit boards, and other items for homebrewers. A price list is also available. Circle 593 on inquiry card. September 1980 © BVTE Publications Inc 345 WbstVNGW? SOFTWARE High-Resolution Package for the AIM-65 The MTU K-1009-1C Text/Graphics Printout program permits the AIM-65 to print text and high-resolution graphics without modifications to the computer or the printer. The contents of the AIM-65 text buffer are reproduced as ten lines of up to 127 characters per line. The display is created as a 320-by-200 dot matrix. The program provides the Quick Print mode that generates the im- age on one paper strip, and the Quality Print mode that generates the image as two 320-by-lOO strips to be taped together. The program is priced at $25 from Micro Technology Unlimited, 2806 Hillsborough St, POB 12106, Raleigh NC 27605, (919) 833-1458. Circle 594 on inquiry card. Genealogy Program AppleRoots is a genealogy software package that can be used for human or animal genealogy. It has seventeen user- definable fields. Functions include system initialization; record entry, change, delete; print index or records; print list of children, family records, or four-generation pedigree chart. All printer functions can be displayed on the screen or sent to the printer. All func- tions are menu-oriented and no pro- gramming is required to customize the system for personal use. The package is written in Applesoft and requires one disk drive and an Apple II with 24 K bytes of programmable memory. The system sells for $39.95 from Computer Data Systems Corporation, 695 E 10th N, Logan UT 84321, (801) 753-6990. Circle 595 on inquiry card. Educational Software Educational Software, 801 E 6th Ave, Helena MT 59601, developers of educa- tional software for the preschool thru eighth grade student, has announced a line of programs for the home-computer user. The programs provide positive feedback and cover a wide group of sub- jects for the young home-computer user. The programs measure the user's perfor- mance during each session and are designed for easy modification by the consumer. Circle 596 on inquiry card. XYBASIC Interpreter for 8080, 8085, and Z80 Systems XYBASIC is a language designed specifically for measurement and process control. It offers the standard features of BASIC plus machine-language linking, software interrupts, and bit manipula- tion commands. Versions are available for SBC/80, CP/M, ISIS-II, Intellec 8 Mod 80, and MDS-800 systems. The nonstandard XYBASIC versions, with a patchable I/O (input/output), make the language adaptable for 8080, 8085, and Z80 sytems. By allowing XYBASIC and the user's program to be placed in ROM (read- only memory), a program can be developed on the target system, put in ROM, and run. This eliminates the problems of floppy-disk program storage in hostile environments. XYBASIC op- tions include a 9511 version utilizing the floating-point circuit, an EDIT version providing edit commands, an extended disk version for use with CP/M systems, and a real-time clock version for SBC/80S. XYBASIC is available in in- teger or extended forms. Versions start at $350. Custom versions can be made. For information, contact Mark Williams Company, 1430 W Wrightwood, Chicago IL 60614, (312) 472-6659. Circle 597 on inquiry card. Apple Users Gain Access to Dow Jones News and Stock Quotes Apple Computer Inc, 10260 Bandley Dr, Cupertino CA 95014, (408) 996-1010, has introduced the Dow Jones News and Quotes Reporter, a software package that puts Apple users in touch with financial news. The program retrieves, displays, and optionally prints selected news stories from the Dow Jones News Service, the Wall Street Journal, and Barron's magazine, plus it can list price quotations for more than 6000 securities. The user gains access through a telephone and modem, and, to access news stories, the user selects News Retrieval Service from the menu. Once a password has been verified, the user can select a news category or company, scan a list of headlines about it, and view the story. Stock quotes can be gained in the same way. The system will run on an Apple II or Apple II Plus with a minimum of 48 K bytes of program- mable memory. Also required are a 16-sector format Apple Disk II with a controller, a modem, a video monitor, and a telephone. A printer is optional. Owners will receive $25 of connection time when they purchase the package, which retails for $95. Circle 598 on inquiry card. CP/M Advanced BASIC Compiler This compiler, called the Topaz Com- piler, produces a relocatable object file that is auto-linked with several libraries to produce a CP/M-compatible .COM file. Two types of floating points are available as well as integer and a fixed- point format. The compiler supports REPEAT... UNTIL, WHILE... DO, IF...THEN...ELSE, BEGIN. ..END, and CASE... OF techniques. All structured statements may be nested. The compiler supports double- and single-precision floating point, fixed-point packed binary-coded decimal, integer, string and character data types. Disk files may use a packed binary format or an ASCII (American Standard Code for Informa- tion Interchange) storage format. Any -COM file can be loaded and executed from control of a BASIC program. Commands can be executed under pro- gram control after the .COM file is finished. The price is $249.95 from Midwest Digital, 863 Wood Ave, Wichita KS 67212, (316) 721-1671. Circle 599 on inquiry card. 346 September 1980 © BYTE Publications Inc What l8 New?" SOFTWARE Symbolic Dissassembler for 6809 Computers The 6809 symbolic disassembler is written for users of the 6809 microprocessor. DISASM6809 is re- entrant, able to be put in ROM (read- only memory), and position- independent. It is called as a subroutine once for each instruction to be disassembled. All necessary parameters, including the address of the user's out- put routine, are passed in registers. The disassembler can produce alphanumeric symbols in both the label and operand fields. Invalid op codes are detected. The program requires under 2 K bytes of space and uses approximately 32 bytes of memory on the calling stack. Output format is syntactically identical to Motorola's assembly- language definition. DISASM6809 is available as a commented assembly listing with instructions for $25. Contact C R Bilbe, 6933 Cedarwood Cir, Colorado Springs CO 80918. Circle 600 on inquiry card. Order-Entry Software Package for Small Businesses Order Entry will handle the documen- tation and control of purchasing and sales. The information from Order Entry can be processed through the accounts payable, accounts receivable, inventory control, and general ledger programs from Compumax, updating these modules to reflect purchase and sales ac- tivity. Order Entry includes generation and printing of purchase and sales orders, computation of tax and registra- tion of deliveries against outstanding purchase orders and of shipments against outstanding sales orders, along with complete purchase and sales order history reports. The program is available in Micropolis 1053/11 (48 K), Apple II, PET (DOS 2.0), and Microsoft under CP/M versions. For further infor- mation, contact Compumax, POB 1139, Palo Alto CA 94301, (415) 321-2881. Circle 601 on inquiry card. Microsoft BASIC Interpreter for the Z8000 BASIC-Z8000 is an interpreter for the 16-bit Z8000 microprocessor. This inter- preter uses an expanded internal nota- tion that takes advantage of the Z8000's 32-bit instructions. The accuracy of in- ternal calculations is in excess of eight digits for single precision and eighteen digits for double precision. Variables are stored using the proposed IEEE (Institute of Electrical and Electronics Engineers) standards, allowing for a double- precision range of exponents from —308 to +308. BASIC-Z8000 is fully language-compatible with Microsoft's BASlC-80 and -86 interpreters. Release 5.0. Microsoft BASIC progams can be run on the 8080, 8086, Z8000 inter- preters without modification. Evaluation copies of BASIC-Z8000 may be pur- chased for $350 (extended) or $600 (disk), from Microsoft, 10800 NE 8th St, Suite 819, Bellevue WA 98004, (206) 455-8080. Circle 602 on inquiry card. Be a BYTE Author With BYTE's recent growth, we are now able to offer you more of the best articles and features about personal computing. Since much of the information in BYTE is supplied by you, the reader, you now have an even better chance to be a paid BYTE author. Our current needs include: • Articles: BYTE Is always looking for well-written articles that cover the field of microcomputing. • Hardware/Software/System Reviews: BYTE is expanding its review of hardware, software, and computer systems. We are looking for detailed, comprehensive reviews as well as short (one- to three-page) reviews. • Technical/Education/Languages Forums: These forums allow readers to take a stand on various issues or to clarify points made in the magazine. • Programming Quickies: Do you have a program you'd like to share as a Programming Quickie? Send it in with a page or two of explanation. • Systems Notes, a new feature, is devoted to sharing both hardware and software tips and techniques that you've found useful for any microcomputer brand or homebrew design. We will pay $20.00 for short submissions and the stan- dard BYTE rate for articles that are one typeset page or longer. We are interested in material about the Apple, Radio Shack TRS-80, Commodore PET/CBM, Exidy Sorcerer, Atari, Ohio Scientific, Compucolor, Microsoft BASIC, CP/M, and S-IOO-bus computers. as well as other computer brands and homebrew designs. Undocumented information about a par- ticular computer (eg: machine-language routine entry points) is also useful. General Format and Treatment All submissions, including letters and other nonpaid material, should be typed, double spaced, and on white paper. All listings should be computer printouts using a fresh ribbon and unlined white paper only. (Look closely at your printout to make sure that the typeface is as dark and solid as possible so that we can photo-reproduce it for the magazine printing.) Cassette tapes or 5-inch floppy disks are acceptable, as are 8-inch CP/M floppy disks. No unused submissions can be returned without a self-addressed envelope and sufficient postage. We will accept or reject each submission within three months of receipt, four months for articles. Full payment for short submission or advance partial payment for articles and larger submissions will be sent with the letter of acceptance. Completing payment for articles and longer submissions will be sent at the time of publication. Standard BYTE payment, except where noted above, is $50 per magazine page of material. We hope to hear from you soon. Would you like to know more about being a BYTE author? If so, then send a large, stamped, self-addressed envelope to: Author Information BYTE Publications 70 Main St Peterborough NH 03458 September 1980 © BYTE Publications Inc 347 Wbsl^New? SOFTWARE Civil Engineering Package The USA Civil Engineering package from Universal Software Applications Inc, 13001 Cannes Dr, St Louis MO 63141, (314) 878-1277, consists of three independent programs. The first is the USA COGO Civil Engineering Coor- dinate Geometry program that can be used for right of way surveys, highway design, bridge geometry, interchange design, construction layout, airport design, and other applications. Some of the COGO commands included are distance, locate/azimuth, locate/bearing, inverse/azimuth, points/intersect, azimuth/intersect, arc/line/points, arc/arc/intersect, area, simple/curve, and deflection/LS. The second program is available for roadway design or subdivision design; it is entitled the USA Earth Design Earth- work Quantities program. It features in- dependent input files for vertical curve, existing ground, proposed section, and design requirements files. Output is by section and includes the station, eleva- tion of profile grade, assumed factors for cut and fill, area, volume and ac- cumulated volume. Finally, there is the USA Stress Struc- tural Engineering Systems Solver which performs linear analysis of elastic, statically-loaded plane-framed struc- tures. Structure, number of joints/members/loadings, joint coor- dinates, member incidences and proper- ties, loading, member and joint loads, tabulate, solve, and stop, and a host of other commands are included. Output consists of the input structure data for each loading condition, the horizontal, vertical, and rotation components of deflection at each joint, the axial forces, shear forces, and moments at the ends of each member or optionally at interior points. The programs will run on Z80, 8080, and 6502 systems with a minimum of 32 K bytes of memory. The one-time lease price is $1000 for individual pro- grams, $2250 for all three programs, and $1750 for any two. Circle 603 on inquiry card. Apple II Statistical Program Rosen Grandon Associates has an- nounced A-STAT 79, a general-purpose statistical package for the Apple II. The system is a subset language of the P-STAT 7% package for mainframe com- puters. The program can have as many as forty-five variables for each of 2000 cases. A-STAT is designed for market research, survey analysis, social and economic modeling, simulations, or teaching statistics. Statistical procedures include file definition and descriptive statistics, frequency distributions, bivariate frequency distributions, the ability to create square correlation matrices, multiple regression and path analysis of linear combinations of variables, permanent file modification, variable transformations, and descriptive statistics file production, and more. A-STAT runs on the Apple II or Apple II Plus systems with 32 K bytes of memory and Applesoft in ROM (read- only memory), or 48 K bytes and Applesoft software. One or more floppy-disk drives are required. It is priced at $100 from Rosen Grandon Associates, 296 Peter Green Rd, Tolland CT 06084. Circle 604 on inquiry card. COBOL for the TRS-80 Radio Shack COBOL can make the TRS-80 Model II compatible with many existing COBOL programs, including some written for mainframe computers. This development system offers multikey ISAM (index sequential-access method) files. Features include a one-pass com- piler, full screen formatting, full ANSI (American National Standards Institute) Level 2 I/O (input/output), program linkage, and segmentation. The Radio Shack COBOL development system, with a reference manual, user's guide, sample program, and floppy disk is priced at $299 from participating Radio Shack stores and dealers, and Radio Shack Computer Centers. Circle 607 on inquiry card. polyFORTH-CP/M polyFORTH-CP/M from FORTH Inc can run on nearly any 32 K-byte or larger CP/M-based system. The pro- gram resides on a CP/M floppy disk as a command file. When loaded, it finds and links up to the CP/M I/O (in- put/output) drivers, initializes itself, and responds "up" on the system console. The program runs in place of CP/M, utilizing only the CP/M I/O drivers. FORTH Inc's 8080 polyFORTH system on a floppy disk and a manual con- taining the interface material are pro- vided. A CP/M utility that allows transferring polyFORTH blocks to a CP/M file and transferring a CP/M file to polyFORTH blocks is also provided. Source code is supplied for the entire system. polyFORTH-CP/M is available from M & B Design, 820 Sweetbay Dr, Sunnyvale CA 94086, (408) 243-0834, for $4750. Circle 608 on inquiry card. Inventory-Control System for Cromemco Computers Feith Software has announced the release of its inventory-control system for manufacturers, wholesalers, and retailers. It is designed to run on any Cromemco- or CP/M-compatible system having dual floppy-disk drives, 48 K bytes of programmable memory, and a 132-column printer. It features parts ex- plosions of finished goods and assemblies, automatic generation of pull sheets, and it will remove parts from stock after a production run. A full audit trail of inventory transactions is maintained. The capacity of the system on a double-density 8-inch floppy disk is over 2000 inventory items and 2000 transactions per disk. Reports are pro- vided for economic order quantities, reordering, ABC analysis, and stock status. The package comes on an 8-inch floppy disk, with a manual and program listings for $250. For details, contact Feith Software, Cedarbrook Hills A-1103, Wyncote PA 19095, (215) 887-9780. Circle 605 on inquiry card. Z8000 Software from Hemenway The RAZ8002ML resident assembler, which includes the LINKZ8002 linking loader, comprises a two-pass macro- assembler and a one-pass linking loader. They are designed to run under Hemen- way Associates Inc (located at 101 Tre- mont St, Suite 208, Boston MA 02108, (617) 426-1931) HA-CP/Z8000 operating system in a 32 K-byte system. The RAZ8002ML has full macroassembler facilities and conditional assembly of up to eight nested levels. It produces a listing and a sorted-symbol table that generates relocatable and linkable object code. The program uses a hash-coded symbol table and binary search of the mnemonic table, and it allows separately assembled routines to share data for production of programs suitable for ROM (read-only memory) circuits. All Zilog-defined op codes are recognized, and a set of pseudo-operation instruc- tions is included. The program is priced at $350. Circle 606 on inquiry card. 348 September 19S0 © BYTE Publications Inc ^1 PRIORITY ONE ELECTRO. MULTIMODE FLOPPY DISK CONTROLLER ll|^H ralifnrniarnmniitprSvQtpm^ CCS-2422 HUVJ (California (lompuier Systems ^OPy^ ' Factory Assembled & Tested ' Based on Western Digital 1793 ' IBM Format Compatible ROM Controlled Addressing Aulo Boot • Single and Double Density • 5'// and 8" Drives ''l/f o Write Precompensation ^3* ' Fast Seek if Voice Coil Type Drives ' Auto Eject (Persci) ' Read Data Separator ' Data Input Filtering I Digital Data Separator ' 2K Byte EPROM (2716) (or Auto Boot ' Auto Wait Port Select ' Led's to Indicate Boot. Select and Bank > Foui Drive Select Lines Drive Compatibility liitef faces to both 5 25" and 8" double- and single-sided drives in any combination up to tour dnves total Is bus-compatible with Shugart ci(UlMemorex5 25'ancl8"drivesand can be madecompatiblewith a Wide variety of soft-sectored drives. For voice coif dnves. fast seek optiralion can be eiUier software or hardware enabled Disk ContrDller Chip Uses the power ful Western Digital 1793 disk controller chip This chip ptOvides IBf^-compatible single and double density tormatting. per- toims the lead data separation, provides comprehensive track and sector status information, etc. Bank Select Cnn be hardware-assigned to one of eight banks Bank then software- selected by ou''-iutting bank select byte to port AOh Bank-select system can be disabled entirely or |ust at power-on and reset so ttiat Uoivti comes up enabled. Onboard ROfV) Conies with on-board. 2K EPROfVI containing both monitor firmware and a bootstrap loader tor loading CPIM from disk. Board can be uonliguied to either load in CPIM on system, systempower-on and reset Of on a monitor command After CPIM is loaded, monitor and bootstrap loader are disabled. The monitor firmware contains loutifies for reading and writing to/from disks, for dumping, moving, rind changing memory, etc POM. when selected, generates the PHANTOfVI line for memory overlay. ROfVIs selection handled by 150mA: -16V (5) 70mA max. • No software initialization required lor board operation, although board parameters may be altered by software 2 lbs. Reg. Sale GBT - INTERFACER I UKT $199.00 $189.00 GBT - INTERFACER I A&T $249.00 $219.00 INTERFACER II The new Interfacer II l/Oboard incorporates onechannel of serial I/O with all the features of the INTERFACER dual RS232 serial board, plus 3 full duplex Parallel ports. The serial section includes all the features you've come to expect- a hardware UART, on-board crystal controlled Buad rate genera- tor, hardware/software programmability, RS232 handshaking lines with real RS232 drivers, current loop & TTL drivers, full interrupts and more!!! The parallel selection utilizes LSTTL octal latches for latched input & output data with 24mA drive current, attention, enable & strobe bits for each parallel port (each with selectable polarity), interrupts for each input port, separate 25 pin connectors with powerforeachchannel anda status portforinterruptmask and port status. All in all - an incredibly flexible and easy to use board. Reg. Sale GBT - INTERFACER II UKT $199.00 $189.00 GBT - INTERFACER II A&T $249.00 $219.00 ECONOROM 2708 Has provisions for wait states for 4MHz operations. Configured as four 4K blocks - each independently addressable and disable- able. Power-on jump. Does NOT include 2708s. Includes all sup- portchips, sockets, regulators, heat sinks, etc. Sold in UNKIT form only. Shipping Weight 2 lbs. GBT - ECONOROM 2708 UKT S85.00 o>5^ ^^'^ Reg. GBT-SPECTRUfVI (Color grapfiics) KIT. 339.00 GBT-SPECTRUfVl (Color graphics) A&T. 399.00 GBT-CPU-Z80 KIT. ... 225.00 Sale GBT-CPU-Z80 A&T 319.00 GBT-CPU-8085 KIT 349.00 GBT-CPU-8085A&T 210.00 GBT-CPU-8085/8088 KIT. Reg. Sale .295.00 269.00 ,235.00 220.00 . 325.00 259.00 .385.00 365.00 v^e^ A^'^ ^^' Reg. Sale GBT-CPU-8085/8088 A&T 495.00 449.00 GBT-BOX-DESK (8-100 Mainframe) 289.00 269.00 GBT-BOX-RACK (S-100 Mainframe). . .329.00 309.00 ECONORAM XIV 16Kx8forS-100.Addressableonany4K boundary. Directaddressingonupto24 address lines. Fully meets lEEES-IOObuss. specs. Low power, hi speed static memory. Operates up to SMHz with newest 8085/8086/8088 CPUs. Can be used with 8080, Z80. 8085. 8086. 8088. Z8000. etc. Reg. Sale Reg. Sale GBT - ECONORAM XIV UKT $299.00 $279.00 GBT - ECONORAM XIV A&T $349.00 $298.00 PRIORITY ONE ELECTRONICS Circle 263 on Inquiry card. PRIORITY ONE ELECTRONICS Features: • 'QM at 8 Amps • '1Q\/at4Amps • 16V at 1 Amps • 110V/220V Adjustable Input • Industrial Quality • Fused Outputs • Conservatively Rated • Rack Mountabie • Cut Out for Fan • Manufactured by Alpha Power • Brand New! • Documentation Included Priority 1 Eiectronics made this special pur- chase when a large OEM customer defaulted. Take advantage of the Great Opportunity! HURRY, limited quantity. At these prices they won't last long. S-100 POWER SUPPLY SPECIAL PURCHASE or 2 for $60 00 TRS-80/APPLE MEMORY EXPANSION KITS ^ 4116'sRAMS ufMmi i Wim ./8for$48'» ADD $3.00 FOR PROGRAMMING JUMPERS FOR TRS-80 KEYBOARD 4116's 100 pes & UP $5.20 each "^^ 1000 DCS & UP $4.45 each. s- COMPUTER SYSTEMS I INC. Z+80CPU IEEE S-100 COMPATIBLE PI EXPANDABLE + DYNAMIC MEM0RY(16K to 64K) + IK Ram On Board + 2 Programmable Timers + Switch Selectable 2 or 4 MHZ ■•■ Power On Jump to On-Board IK or 2K EPROM (2708-2716-2732) Can be Addressed on any IK, 2K or 4K Boundary Bare Board $ 45.00 A&T $229.95 Kit $169.95 IK Memory Kit $ 12.00 Programmable Baud Rate Selection (110 to 9600) On-Board EPROM May be Used in Shadow Mode, Allowing Full 64K RAM to be Used On-Board USART lor Synchronous or Asynchronous | RS-232 Operation (On-Board Baud Rale Generator) + Works With Cromenco Systems + + Uses 3242 Refresh Chip + 4 Layers Mean A Quiet Board + I Bare Board $ 49.95 32K Kit 16K Kit $295.95 32K A&T 16KA&T $345.95 48K Kit $444.95 Bank Selectable Write Protect Phantom Output Disable Switch Selectable Output Disable $369.95 48K A&T $494.95 $419.95 64K Kit $519.95 CLOCK CALENDAR + + Time of Day in Hours, Minutes and Seconds + 24 Hour Time Format Month and Day Date Function 64KA&T $569.95 Bare Board $45.00 Kit $99.95 A&T $149.95 Simple Read Instructions Allow Simple Interface to Basic, CPM, Etc. Will Run With 4 MHZ Processors Can be Located at any Group ol 4 1/0 Port Addressed I LIST PRICE ^79^^ SALE PRICE ^59^^ ORDER G0M8AR4e PROTECT YOUR INVESTMENT PROTECT YOUR OATA WITH THE ISOBAR ELECTRICAL OUTLET STRIPCONSISTSOF A MASTERPOWERSWITCH, INDICATOR, AND 4 INDIVIDUAL 3 WIRE OUTLETS, EACH WITH ITS OWN NOISE FILTER AND SURGE SUPPRESSORTO PROTECT YOUREQUIPMENT FROM DANGER- OUS TRANSIENTS FROM OTHER EQUIPMENT PLUGGED INTO YOUR ISOBAR OR FROM WHATEVER THE POWER COMPANY IS DOLING OUT WARNING: "Murphy's Law" predicts that after reading this ad and not acting, your equipment will soon be destroyed by a fatal Glitch. ^•njv*^ GOLD 3 LEVEL WIRE WRAP f,t6 SOCKES 14, 16 & 24 PIN RNS-14G3 120/842.00 RNS-16G3 104/S40.00 RNS-24G3 51/536.00 TILOW PROFILE SOCKETS TIS-16LP 10Q/SI6.00 TIS-MLP 100/S14.00 RS232and "D" SUB-MINIATURE CONNECTORS P = Plug. IVIale Type - S = Socket. Female Type - PART NO. DESCRIPTION IS C = Cover, Hood PRICE . 10-24 CN0-DE9P 9 PIN MALE $ 2.10 $ 1.90 CN0-DE9S 9 PIN FEMALE S 2JD S 2.40 CN0-0E9C 9 PIN COVER S 1.50 S 1.25 CND-0AI5P 15 PIN MALE S 2.75 S 2.45 CN0-0A15S 15 PIN FEMALE S 3.95 S 3.60 CN0-DA15C 15 PIN COVER $1.50 S 1.30 CN0-0B25P 25 PIN MALE $ 3.50 S 3.25 CN0-0B25S 25 PIN FEMALE $ 4.60 S 4.35 S 4.20 CN0-D851212 1 PC. GREY HOOD $ 1.60 $ 1.45 $ 1.30 CND-P25H 2PC.GREYH000 S 1.50 S 1.25 CNO-0851226 2 PC. BLACK HOOD $1.90 $1.65 CN0-DC37P 37 PIN MALE S 5.80 S 5.10 CNQ-0C37S 37 PIN FEMALE $8.70 S 7.70 CN0-DC37C 37 PIN COVER $ 1.80 $ 1.55 CN0-D050P 50 PIN MALE $8.75 $7.75 CN0-0050S 50 PIN FEMALE $11.65 S10.25 CN0-0050C 50 PIN COVER $ 2,00 $ 1.80 CND-D20418 HARDWARE SET 2 PR. $1.00 S 0.80 CND-RS2328FcLAslfcABLE8C0^^ FT. 519-95 $17.95 $15.95 CND-5730360 RRiNTER^CONNEaOR « 9-00 S 7.50 $ 6.00 25-99 S 1.70 S 2.10 S 1.10 S 2.15 $ 3.20 S 1.10 S 3.00 % 1.10 S 1.45 S 4.45 S 6.70 S 1.30 S 6.70 S 8.90 S 1.60 S 0.70 3 LEVEL GOLD WIRE WRAP SOCKETS PRICE* 'Pries basod on gold not exceeding $400.00 per oz. \ferbatim Pan No. SeclorinQ Pk. ol Z Box ol 10 VflBMD 525DI vubmqszsio VRBMQ5Z5)6 VflBfD3Z!000 VflBFD34IOOO Soil Secioi Hafd lOSectof Hard iSSeclot HatdSecioi SoitSectO) Mfctopolis Sliug.itiaOil IBM 3/40 S 8.95 S 8.95 J 8.95 sn.95 S1I.95 S2995 SZ9.S5 JZ9.95 $37.00 S37.00 SHIPPING WEIGHT I LB BE SURE TO ORDER YOUR KASSETTE/10 LIBRARY CASE BELOW KASETTE/10 LIBRARY 10 300 baud data rate. Compatible with Bell 103 and 113, Answer/Originate. Full/ Half Duplex. Special self test features. THE STAR MODEIVI FROM LIVERMORE LIST PRICE $199.00 SALE PRICED $139.00 MEMORY HEADQUARTERS me 16K 5 Volt only EPROM. ne^^ea;; 2708 8K 450ns EPROM 8/^55°° :il14-3L 1Kx4 300ns Low Power. 8 M5°° lOO-fM^'^ea, 5257-3L4Kx1 300ns Low Power. .8/*55''° 100 + *52Sea. 2102AL-2 U9 250ns in lots of 20, 1.25 ea. 100+ 1.10 ea. BLACK 8" DISKETTE BLUE HOLDER $4.50 BIEGE or3/$11.00 BLACK 5'.' DISKrnE fCni HOLDEr, $1.25 ""^^l^ or 3y$10.00 'CALIFORNIA __ Computer Systems • S-100 compatible • Industrial/commer- cial quality construction • Flip-top cover • Excellent cooling capability • 12 slot capability (uses model 2501 A) • Input 105, 115, or 125 VAC • Output + 8 VDC20A, + -16 VDC 4A • Active ter- mination of all bus lines • Fan and cir- cuit breaker included • Rugged con- struction CCS-2200A Assembled & Tested 35 lbs $399.95 CCS-2200AK Kit 35 lbs $349.95 Circle 263 on inquiry card. PRIORITY ONE ELECTRONICS 16723K Roscoe Blvd. Sepulveda, CA 91343 Terms: Visa, MC, BAG, Check, Money Order. U.S. Funds Only. CA residents add 6% sales tax, Minimunn order S10.00 Prepaid U.S. orders less than $75.00 include 5% shipping and handling. MINIMUM $2.50. Excess refunded. Just In case ... please include your phone no. Prices subject to change without notice. We will do our best to maintain prices thru Sept 1980. 'SOCKET and CONNECTOR prices based on GOLD, not exceeding $500 per oz. 'Sale Prices are for prepaid orders only credit card orders will be charged appropriate freight PRIORITY ONE ELECTRONICS FOR MORE INFORMATION SEE I OUR 52 PAGE AD in JANUARVl BYTE OR SEND $1.00 FORI CATALOG ■ Sale Prices are for prepaid I orders only • Quantities are | limited, subject to prior sale CREDIT CARD ORDERS WILL BE I CHARGED APPROPRIATE! FREIGHT BYTE September 1980 351 7400 74LS00 SN7400N .19 SN74123N 59 74LS00N 35 74LS164N 1.19 SN7401N .22 SN74125N .39 74LS01N 28 74LS165N .89 SN7402\ 22 SN74126N .44 74LS02N 28 74LS166N 2.48 SN7403N 22 SN74128N .59 74LS03N 28 74LS168N 1.89 SN7404N 22 SN74132N .69 74LS04N 39 74LS169N 1.89 SN7405N .23 SN74136N .95 74LS05N 28 74LS170N 1.99 SN7406N .23 SN74139N' .95 74LS08N 39 74LS173N .89 SN7407N .23 SN74141N .69 74LS09N 39 74LS174N .99 SN7408N .26 5N74142N 2.95 74LS10N 28 74LS175N .99 SN7409N ,23 SN74143N 2.95 74LSnN 39 74LS181N £.20 SN7410N .22 SN74144N 2.95 74LS12N 39 74LS190N 1.15 SN7411N .29 SN74145N 62 74LS13N 47 74LS191N 1.15 SN7412N 29 SN74147N 1.95 74LS14N 1.25 74LS192N .98 SN7413N .39 SN74148N 1.20 74LS15N 39 74LS193N .98 SN7414N .59 SN74150N 99 74LS20N 26 74LS194N 1.15 SN7416N .29 SN74151N .67 74LS21N 38 74LS195N .95 SN7417N .29 SN74152N- .67 74LS22N 38 74LS196N .89 SN7420N .22 SN74153N .67 74LS26N 39 74LS197N .89 SN7421N ,35 SN74154N 1.19 74LS27N J9 74LS221N 1.49 SN7422N .29 SN74155N .82 74LS28N 39 74LS240N 299 SN7423N .29 SN74156N .89 74LS30N 26 74LS241N 2.49 SN7425N .29 SN74157N .69 74LS32N 39 74LS242N 229 SN7426N 29 SN74158N 1.65 74LS37N 79 74LS243N 2.29 SN7427N 29 SN74160N .95 74LS38N 39 74LS244N 2,95 SN7429N .45 SN74161N ,95 74LS40N 26 74LS245N 8,95 SN7430N ,23 SN74162N .89 74LS42N 79 74LS247N 1,10 SN7432N .29 SN74163N .87 74LS47N 79 74LS248N 1.10 SN7437N .29 SN74164N .97 74LS48N 79 74LS249N 1.69 SN7438N .29 SN74165N .97 74LS51N 26 74LS251N 1.79 SN7439N .29 SN74166N 1,20 74LS54N 35 74LS253N ,98 SN7440N .24 SN74167N 1,95' 74LS55N 35 74LS257N ,98 SN7441N 79 SN74170N 1,69 74LS73N 45 74LS258N 98 SN7442N 57 SN74172N 5.95 74LS74N 59 74LS259N 2,95 SN7443N .79 SN74173N .79 74LS75N 68 74LS260N 69 SN7444N .79 SN74174N ,89 74LS76N 45 74LS261N 249 SN7445N .79 SN74175N .89 74LS78N 65 74LS266N ,59 SN7446N .79 SN74176N .85 74LS83AN 99 74LS273N 1.75 SN7447N .59 SN74177N .85 74LS85N 1 19 74LS275N 4.40 SN7448N .79 SN74179N 1.80 74LS86N 45 74LS279N .59 SN7450N 23 SN74ieON ,75 74LS90N 75 74LS283N 1.10 SN7451N .23 SN74181N 1.75 74LS92N 75 74LS290N 1.29 SN7453N ,23 SN74182N ,75 74LS93N 75 74LS293N 1,95 SN7454N ,23 SN74184N 1,95 74LS95N 88 74LS295N 1,10 SN7459N 29 SN74185N 195 74LS96N 98 74LS298N 129 SN7460N 23 SN74186N 9,95 74LS107N 45 74LS324N 1,75 SN7470N .39 SN74188N 3.90 74LS109N 45 74LS347N 1.95 SN7472N .34 SN74190N 1.15 74LS112N 49 74LS348N 1.95 SN7473N .38 SN74191N 1.15 74LS113N 49 74LS352N 1.65 SN7474N 36 SN74192N fl5 74LS114N 55 74LS353N 1-,65 SN7475N .38 SN74193N .85 74LS122N 55 74LS363N 1,49 SN7476N ,36 SN74194N .85 74LS123N 1 19 74LS365N .99 SN7479N 4.60 SN74195N .85 74LS124N 1 35 74LS366N .99 SN7480N -59 SN74196N .85 74LS125N 89 74LS367N .99 SN748JN 1.10 SN74197N .85 74LS126N 89 74LS368N .99 SN7482N 1.10 SN74198N 1-39 74LS132N 79 74LS373N 2.75 SN7483N .55 SN74199N 1.39 74LS136N 59 74LS374N 2.75 SN7485N 65 SN74221N 1.39 74LS138N 89 74LS375N .69 SN7486N ,39 SN74251N .95 74LS139N 89 74LS377N 1.95 SN7489N 1,75 SN74273N 1.05 74LS145N 1 25 74LS385N 1,95 SN7490N .39 SN74279N .89 74LS148N 1.49 74LS386N ,65 SN7491N ,65 SN742e3N 2.15 74LS151N 79 74LS390N 1,95 SN7492N ,52 SN74284N 3.90 74LS153N 79 74LS393N 1.95 SN7493N .49 SN74285N 3.90 74LS154N 2 49 74LS395N 1.70 SN7494N .7 2 SN74290N 1.25 74LS155N 1 19 74LS399N 2.95 SN7495N 65 SN74298N 95 74LS156N 99 74LS424N 2,95 SN7496N .72 SN74365N .68' 74LS157N 99 74LS668N 1.75 SN7497N 310 SN74366N .68 74LS158N 75 74LS670N 2,29 SN74100N .99 SN74367N ,79 74LS160N 98 81LS95N 1.99 SN74107N ,32 SN74368N .79 74LS161N 1 15 81LS96N 1,99 SN74109N ,53 SN74390N 1.90 74LS162N 98 81LS97N 1,99 SN74116N 1,95 SN74393N 1.90 74LS163N 98 81LS98N 1,99 SN74121N .29 SN74490N 1.90 SN74122N .39 1 ^%#^ Lir. II EAF { c rlM lOS 78H05 5,95 LM1414N 1,90 CD4000 ,29 CD4093 .99 76M06 1 49 LM1458CN/N .49 CD4001 .29 CD4094 2.95 78M.G. 1 49 MC1488N 1.49 CD4002 ,29 CD4098 2-49 LM105H 99 MC1489N 1,49 CD4006 1,39 C04099 2-25 LM108AH 2.95 LM1496N .89 CD4007 ,29 MC14408 12.95 LM300H 79 LM1556N 1.50 CD4008 1,39 MC14409 12,95 LM301CN/H 35 LM1800N ,79 CD4009 ,59 MC14410 12.95 LM304H 98 LM1820N ,95 CD4010 ,59 MC14412 12.95 LM305H 89 LM1850N ,95 CD4011 29 MC14415 8,95 LM306H 325 LM1889N 3,95 CD40T2 ,29 MC14419 495 LM307CN/H 29 LM2111N 1,75 CD4013 49 CD4501 ,39 LM308CN/H 98 LM2900N ,99 C04014 1,39 C04502 1,65 LM309K 1 49 LM2901N 2.50 C04015 1,39 CD4503 ,69 LM310CN 1 25 LM2917N 2,95 CD4016 ,59 CD4505 8,95 LM311D/CN/H 98 CA3013T 2,29 CD4017 1,19 CD4506 ,75 LM312H 1 75 CA3018T 1.99 CD4018 1 19 CD4507 ,95 LM317T 2.75 CA3021T 3,49 CD4019 49 C04508 3,95 LM318CN/H 1 49 CA3023T 2,99 CD4020 1 19 CD4510 1,39 LM319N/H 1 25 CA3035T 2,75 CD4021 149 CD4511 1,39 LM320K-XX- 1. 49 CA3039T 1.49 CD4022 1 29 CD4512 1 39 LM320T-XX- 1,25 CA3046T 1.29 CD4023 .38 CD4515 3,95 LM320H-XX* 1 25 LM3053N 1,49 CD4024 79 CD4516 1,69 LM323K 4 95 ■CA3059N 3,25 C04025 38 CD4518 1,39 LM324N 1 25 CA3060N 3,25 C04027 .79 C04520 1,39 LM339N 95 CA3062N 4,95 CD4028 ,99 CD4555 4,95 LM340K-XX- 1 49 LM3065N 1.49 CD4029 1,29 CD4556 ,99 LM340T-XX' 1,25 CA3080N 1.29 CD4030 ,69 CD4566 2,25 LM340H-XX- 1, 25 CA3081N 1,69 CD4031 3 25 74C00 .39 LM344H 195 CA3082N 1,69 CD4032 2 15 74C02 ,39 LM348N 1.85 CA3083N 1.99 C04034 3.25 74C04 39 LM358CN 98 CA3086N 1.29 CD4035 1 19 74C08 ,49 LM360N 1 49 CA3089N 2.75 CD4037 1,95 74C10 .49 LM372N 1 95 CA3096N 2,49 CD4040 1,29 74C14 1.65 LM376N 3.75 CA3097N 1,99 CD4041 1,25 74C20 .39 LM377N 375 CA3130T 2,49 C04042 ,99 74C30 ,39 LM380CN/N 1 25 CA3140T 2,49 CD4043 99 74C32 .99 1.M381N 1 79 CA3146N 2,49 CD4044 99 74C42 1.85 LM383T 1 95 CA3160T 1.49 CD4046 2.25 74C48 2.39 LM386N 1 49 CA3190N 1,95 CD4047 1,25 74C73 .99 LM387N 1. 49 CA3401N ,69 CD4048 69 74C74 99 LM390N 1.95 MC3423N 1,49 CD4049 69 74C85 2.49 NE531V/n 375 MC3460N 3,95 C04050 69 74C69 4,95 NE555V 39 SG3524N 3,95 CD4051 1,10 74C90 1,85 NE556N 98 CA3600N 3.50 CD4052 1,10 74C93 1,85 NE561T 19.95 LM3900N .59 CD4053 1 10 74C95 1,85 NE5628 7.95 LM3905N 1.49 CD4055 395 74C107 1.19 NE565N/H 1.25 LM3909N .98 CD4056 295 74C151 2,49 NE566H/V 1 75 RC4131N 2,95 CD4059 995 74C154 3,50 NE567V/H 1 50 RC4136N 1,10 CD4060 139 74C157 2-10 NE592N 275 RC4151N 4,50 CD4066 89 74C160 2-39 LM702H 2.99 RC4194 4.95 CD4069 35 74C161 2.30 LM709N/H 29 RC4195 4.40 CD4070 ,69 74C163 239 LM710N/H 98 ULN2001 1.25 CD4071 ,35 74C164 239 LM711N/H 39 ULN20a3 1.50 CD4072 35 74C173 259 LM715N 1 95 SN75450N .59 CD4073 35 74C174 2,75 LM723N/H 75 SN75451N .49 CD4075 ,35 74C175 2-75 LM733N/H 98 SN75452N .49 CD4076 1,29 74C192 2,39 LM739N 1 15 SN75453N 49 CD4077 35 74C193 i39 LM741CN/H 33 SN75454N ,49 CD4076 .35 74C195 2,39 LM741CN-14 19 SN75491N .89 CD4081 35 74C922 795 LM747N/H 79 SN75492N 89 C04062 35 74C923 695 LM74aN/H 39 SN75493N .89 CD4085 1.95 MM80C95 150 LM760CN 2 95 SN75494N .89 CD4089 2 95 MM80C97 1,25 LM1310N 1.90 RETAIL STORES OPEN MON-SAT 13tO"B"E. Edinger STORE 674 EJ Camino Rea STORE 13tO"B"E. Edinger #1 Santa Ana, CA 92705 Showrooms, Retail, Warehouse BECKMAIV Digital Multimeters \^S-^ noo° C hoce d Mutos - The re C H 3 ) 1 la s a U aiove leab«K. 7lni 29130365 ("US 025'l«)Vils: actnacy 11-ieTECH3CChasa05%Vdcacciiracyan(!alti' " ' txilwithaut Insta-Odms"" conlmuityluicliixi w II le 1 ampojr- TECH300 Digital Mutlimeler S100. TECH 310 Oigrlal Multimeler S130 VC-201 Vinyl Carrying Case. S10. DC-202 Deluxe Carrying Case S24. HV-21 1 High Vollago Probe S35. RP-221 RPProbe ,....S35. C1-231 ACCurrenlClamp S42. □ L-241 Deluxe TeslLead Kit S10. TL-242 SpareTesI Leads S6. (6 PCS.) MUSIC MACHINE 9"^ WITH 9 VOICES! • NENViUseslaleslSlalecllheAflLSlTectinology • Reouiesotiiyaneiilol tor 9 voices • Uscstl^ee AY3'S9lOslo (Koiiie (we vniss (Offiercn^iiint (TOdeis ha«orily3 VOCES) • IncKxies 5C»l«ae • SmU3t£sll»«ALF Boards • Playsnwsc genoaiefl by ine ALF iaasi • APPIE'" H •oi^riEDe • ALF soffAare requral 3 Times More Powerful Than ALF! KIT JI99 95 ASSEMBLED »N0 TESTED J259.95 THE BONE RONE I*" '> ^X<4^. • SKIERS • JOGGERS • SKATERS • CYCLERS Voumusthear it and feel it to believe it? AM/FM stereo surrounds and tills your txxly with sound No earplugs. You v/ear iC t^k ~®s $65 95 FLOPPY DISK DRIVES MPl B51-5VV', 40 tracks , 279,00 Shugar: SA400-5VV 35 tracks . . , 295,00 Shugat1800/801R 8' 475,00 Siemeris Shugart Compatible Model FDD-1 20-80 429.00 PERSCI Model 277 Dual 1195 00 WANGO/SIEMENS 5'." Drive , . . 290.00 MPl B52 5',VDual 395.00 WANGO/SIEMENS 282 Dual 5V." , . , , 395.00 WANGO/SIEMENS 82 290 00 MONITORS Sanyo 9" 5169,95 Sanyo 15" 279.00 Leedex 12" 139.95 Molorola 1 2". High Resoiulion, 22 MHz, OEM Model 5M3000-340 219,00 Zenith 13"ColorMonilor, , . 499,00 MGA 13"Co)orTV 349.00 VAMPl9"ColorMonilor... 575.00 VAMP 15"Color Monitor. . . 449,00 ^^TB CONTINENTAL SPECIALTIES Msdel 300) Digital Capacitance Meter 27500 Model 333 Tri-Mcde Ccxiiparator 295,00 Modil LM-3 40-channel Logic Monilor , 58500 Model lM-1 Logic Monitor 60.00 Model IM-Z Logic Monitor ., 147.00 MudtlZOOl SweepaUeFurctionGenerator . . . 186,00 Modal SOOl Universal Counter-Timer l , 360,00 Model 6001 650 MHz FfcquencyCainler 385,00 MAX-100 100 MHz Portable Frequency Cajnler , , 14900 PS-500 500 MHz Decade Prescaler 70,00 MUX-SD 50 MHz Handheld Freqttency Counter 77,00 MM-550 550 MHz Handheld Frequeicy Counter , , 165,00 Model 400) Pulse Generator 835,00 Model DP-) Oigilal Pulser 83,00 Logic Probes Model lP-1 Digital Logic Probe 50,00 Model IP-Z Economy Logic Probe 28,00 Model lP-3 High Speed Logic Probe 77 00 Model lPK-1 Logic Probe Kit 21.95 Logic Probe Accessaies 21 Model ITC-l.lTC-Z Logical Analysts Kits 220/250 Ladw\nced computer fPHQDUCTS (Apple II. 16K or Apple II. Plus $990 \\ DISK SYSTEM SPECIAL Apple II Plus W/48K Supermod Video Modulator Disk II w/Controller Integer Based ROM Card. Reg. 32,220.00. ACP Price $ 1 8 1 9.00 SAVE S401 .00 Hi-Speed Serial I/O Centronics Printer I/O Applesolt II Firmware Apple Clock Intfol X-10 System Intfol X-10 Controller Alt Music Synthesizer t6 Ch Analog Input 2 Ch Analog Output 13-Key Keypad ViSi-Calc 518900 OS65 Oigi-Sector 199 95 Apple Graphics Tablet 18900 DC. Hayes Modem II 269 00 Oisk II w/Controller 26995 Disk il Pascal Lang System Parallel Pnntef Card Conimunicadons Ca»d BusinessSoltwarePkg 1799 25995 24995 164 95 11995 12500 S349 00 Integer ROM Card 72500 Pioto Card 349 95 MiRModulalor 55900 Sanyo Cassette 45900 16K Upgrade Kit 45000 Desktop P;an 165,00 8" Floppy CofilroUer 18900 Heuristics Speechlab 62500 Romptus -f Cofvus 10 Megabyte Ori«e Supertalker 4625 00 Casliier S1890Q 2195 2995 54 95 6295 9800 35000 17900 16900 27900 250 00 AATARr8oo&400 >^ Personal Computer System ATARI 800 $825.00 ATARI 400 $449.00 ATARI 800 Includes: Computer Console, BASIC Lang. Cartridge, Education System Master Cartridge. BASIC Language Programming Manual, 800 Operator's Manual w/Notebook, Atari 410 Program Recorder. 16 K RAM Module, Power Supply, TV Switch Box, Pidpliiiiii Stimn-XOHCinuiti Education Sys wn Haste Cad m^ Atari BASIC 59901 49900 C900 2800 SSOO 5500 4200 4200 EdiicitlOB STitim Ctiulli mtnmt us Hisiory US Govw/roenl Supevi^ry Skills World History iWestwn) Base S(i«logy Ciiree»«iQ PiDOKJjes Prnc5*solAc»oufil»ia Great ClascicslEngiiSio Biisiness C onvnunfca loos Basic Psyoiwioa/ . Elleci.vewndnfl Auto Mecrunics PtlKipies of Eioromt 5 Speilinq Base Eieciiicity DasicAigetva Sliic Gi M iti N|n> CuuRit GuOe to BASIC Pro^anmng BASIC GamE Preyaro 8 K RA M llemrt MoUuIe 16KRAM M&niry MoOute inutltit Blank Oiskelles Oisk File Maiiatier lk«u»r) Cinlrtliri Dnving ConlroHer Paii Paddle Controller Pair Jo>stick Conlrodet Pa « Texas Instruments 99/4 personal' COMPUTER Superior Color, Music, Sound and Graphics - and a Powerful Extended Basic -All Built In. Tl 99/4 Console only available for S659.00 $1099.00 C^ commodore PET ,o^^3 $775.00 DISCOUNT PRICES 77500, 202380-ColPiainPapH Pnntet 69500 9750Q 2040 Oui Mim OiSk Onve 125000 97500 Pet lolEEE CaWe 3995 125000 IEEE toiEEE CatHe 4995 125000 C2N ExloiHl Cassette Deck 9500 79500 a lBm,m. without $174.95 $154.95 cruise canlrol Anonboa fl navigatoBlmn^joiei (ojaitcnKtiJes. neks, a^d tECFBatiavat wt»d es. Featires caak con Ud fuel manage men sysienx Bipcavvuler, niiNiiunciioned auatt2 civsiai litre C(xnie<. plusmanycthei ijnctitns HOME BURGLAR ALARM ACP PRICE ONLY $189.00 • No installation • Protects a whole house • Turns on lights automatically • Powerful electric siren • Exit and entry delay • Battery back-up BACK TO SCHOOL SPECIALS Texas Instruments Speak & Spell 559.95 Speak & Spell Modules, 1 5,95 Spelling Bee 32,95 Dataman 21,95 Little Professor.... i3,95 Mr. Challenger , 33,95 30SP Student Math Kit 18,95 Coleco Ouiz Wiz 525,95 Quiz Wiz Cailridges 5,99 Mattel Brain Baffler S45,95 Ttie tfiermostat that uses microprocessor technology to save fuel and money. PROGRAMMABLE r TEMPERATURE CONTROLLER $69.95 A fully automatic electronic thermo- stat. Easy to install and operate. Compare thie cost: TPI's temperature controller is thie lowest priced elec- tronic thiermostat on tfie market. SINGLE BOARD COMPUTER SELECTION GUIDE BOARD KIM-1 SYM-1 Cromemco SD-SBC100 AIM 65 Cosmac Vip PROCESSOR ACP PRtCE ENCLOSURE 6502 169.00 Add 29.95 6502 239.00 Add 39.95 Z80 409.00 N/A Z80 239.00 N/A 6502 375.00 Add 49,95 1802 199.00 Inc. t2 Tustfn, CA 92680 Specializing In Systems P.O. Box 1 7329 Irvine, Calif. 9271 3 Direct Order Lines: (714) 558-8813 (800) 854-8230 or (800) 854-8241 FOR INTERNATIONAL ORDERS: 1401 E. Borchard (714)953-0604 Santa Ana, CA92705 TWX:910-595-1565 352 BYTE September 1980 Circle 264 on inquiry card. X l:=^COMPUTER STATICV IRAN BOARDS^ • S-100 32K (uses 2114) Jj^\^k^! ASSEMBLED Kit I'A* ^ 450ns. 499.00 450ns. 469.00 250ns. 539.00 250ns. 499.00 Bare Board 49.95 Bare Board w/all parts less mem. 99.95 WOW! • S-100 16K (S-1 00 Compatible) • Low Power • 2 MHz or 4 MHz • Assembled & Tested 2 MHZ....S250.00 4 MHz.... S265.CMD • LOGOS I BK ASSEMBLED 450 ns. 149.95 KIT 450ns. 125.95 250ns. 169.95 250ns. 149.95 Bare PC Board w/Data S21.95 "Saecfal Offer" Buy (4) 8K 450ns. Kits SI 1 700 The VISTA V-60 Disk Drive System s,^„ ^,„, ,^,^, • 23% more storage capacply than Iwo drive system ns-io • iJOday waframy • 10 (rack cetcn at NO CHARGE t 39Siia t vom tUSOOD t 3(95 THE VISTA V-200 FOR EXIDY >: Starting as low s $1199.00 ItM CiftdtT C«ril|Q 18.50 Intro to Micros Vol. Ill TfteaiBSO SALE • SYBEX COMPUTER BOOKS • SALE 6502 Games ' . SI? 95 Iniro to Personal Ji Bu'iini's?; Computinci i?V)5 Mircnprocessors From Ctiips Io Systoms 1 2 IF) Microprocessor Inierlacitiy Techniques . . 1235 Progr.imming IheZeO ' 12 95 PiDgramming meZQOOO . 12 95 PfOiiramminq iho 6502 .. .12 95 6502 Applications Boo1( 12 95 FIRST TO OFFER PRIME PRODUCTS TO THE HOBBYIST AT FAIR PRICES! 1 . Proven Quality Factory tested products only. 2. Guaranteed Satisfaction 3. Over $1,000,000.00 Inventory 1980 CATALOG NOW AVAILABLE. Send $2.00 for your copy of the most complete catalog of computer products. A must for the serious computer user. MICROPROCESSORS .SI 89 00 . 14900 ...,10.75 Z6001 16 bit tc Z8002 16 bil tc zao ZSOA F-8(3850) 16.95 2650 18.95 C0 1802 13,95 8060A 8,50 8080A 4WHi 19.95 SALe8085 19,95 8008-1 . 1495 2901 9.90 2901A. 14.95 2903 -t-bil Superslice 29.95 TMS9900JL 49.95 CP1600 39.95 6502 11.50 6502A 16.95 IM6100 29.95 6800 11,75 68008 2.0 MHj 19.95 6B02P 17.95 8035 19.95 8755 49.95 8748 69.95 6809 64.95 8086 69,95 ADVANCED SUPPORT AM951 1 Arith, Processor ... 1 75.00 9512 Arilh Processor 175.00 9513 Univ. Timing 79.95 AM9517 DMA Controller 16.95 AW9519Universann1errup(... 18.95 Z-80 SUPPORT CHIPS 2.5 MHz 875 4.0MHI 12.95 2 5 MHz 8 75 Z60PIO Z80A-PIO Z80-CTC Z80A-CTC Z80-DMA 2.5 MHz 29.95 Z80A-DMA 4.0 MHz 36.95 Z80-SIO/0 2.5 MHz 35.95 •Z80A-SiO/0 4.0 MHZ 39 40 Z80-S1O/1 2.5 MHz 35 95 ZBOA-SIO/l 4.0 MHz 39.40 ZBOSlO/2 2.5 MHz 35 95 Z80-SIO/2 4 0MHi 39 40 8080/8085 SUPPORT 8155/8156 I/O .- 24.95 8755 I/O with Eptom 64.95 8202 Dyn Ram Com 34 95 8205/74S 138 Decoder .... 3 95 821 2 8 bit I/O 2.75 8214 Priority Int 5.25 82I6BUS Driver 2.75 8224 Clock Gen 2.95 8224-4 (4MHz) 9.75 8226 Bus Driver 3.95 8T26 Bus Driver 2.95 8228 Sys, Control 5.50 8238 Sys Cont 5.50 8251 Prog. I/O 6.95 8253 Int. Timer 16.95 8255 Prog. I/O 6.S0 8257 Prog. DMA 16 95 8259 Prorj. Irll. 17.95 8275 CRT Controller 59.95 8279 ProQ. Keyboard 18 95 6800 SUPPORT CHIPS 6810 126 X 8 Ram. 4.75 6820 PIA - 5.95 6821 PIA : 6-50 6628 Priority Int 9,95 6834-1 512x8Eprom 16.95 6845/HD46505 CRT Conl... .39.95 6847 Color CRT 49 95 6850 ACIA .5 95 6852 Serial Adapter 5 95 6860 Modem 10,95 6862Modulator 11.95 6871 A l,0MHzOSC.... 25.95 6875 8.25 6880 Bus Driver .,,2.95 MC66466 1995 68047 24.95 1802 SUPPORT CHIPS 1821 SCD2KRAM 25.00 1822 SCO 256 x 4 RAM 1 6.95 1824 CD 32x8 RAM ...9 95 1852CD8biI l/o 10,95 1854 Uart ..10.95 1856CDI/0 895 1857 CD I/O.. ..8.95 1861 12.95 6502 SUPPORT CHIPS 6520PIA 7.50 6522 Mult 11,95 6530002.003,004,005 2 1 .95 6532 1995 6551 19,95 PROMS 2708 450ns 8.25 2708-6650 ns 7 50 1702A 4.95 2732 74,95 2716-5V , 29.95 2716-5V, 12V 2995 2758-5V 29 95 5203AQ 1395 5204AO 14.95 IM 5610 390 SALE 8223 32x8 2.95 82S115512 x8(rS) 16.95 82512332x8 4.90 825126 256x4 .., 4 90 825129 256 x 4 (T5) 4 90 825130 512 X 4 (OC) 6 50 82523 695 82S131, 14 95 825137 14.95 NOTE: WE PROGRAM PROMS CHARACTER GEN. 25 13-001 (5V)Upper 9 50 2513-005 (5*. Uower... ... 10.95 2513-ADM3(5VlLower . 1495 MCM6571 11.75 MCM6571A 11.75 MCM6574. 14 50 MCM6575 . 14.50 UARTS/BAUD RATE TRt60?B(5V 12VI 3 95 AY51013(5V l?VI AY5101:u 577-10 to HOic HVd (JS Ap,iie f.|c 577'lfi IbHoit njfd Miriiiooiis • 4D IHACKS. double SIOEa. DDUBK IKNSin 5'. 550-01 ScllSecloiK)SA4M MPI W 550 10 tOtloif Kflrti BASr ■■VAltGCO 4702 4 95 V,'D19^il COM 5016 16 95 KEYBOARD ENCODERS AY5-237G 13 75 AY5-3600 13.75 HD0165 9 95 74C922 9,95 FDtflO 01 FDiOOJ? FDI0;:01 ', CtBTlPlEO DISREtTES :'e!)?ns.l, 37-1 leDenv ( Sr.uT Soli Doutiie Derrsil Soil tcutiip SK)f<) OoiDit I'o-Silv 3-« -1980 VOLUME DEALER PRICING AVAILABLE WE ALSO STOCK DYSAN-CALL cFIMS: Use Check, M/C. VISA. AMEX CB o' COD COD requi-es 25''. deposit Charge Orders please include expiration date Foreignpay US Funds Ordfr by phone, mail o> IWX MINIMUM SIO 00 Please in- cludemagazineissueandphoneno SHIPPING US A addS2 00lorl,ri; 2 lbs For surlace add 30c lor add.- honal lbs For air add 70: tor addi- l,«nal lbs FOREIGN Add lOS ship- ping and handlmq COD'sSl 85e«tra Not responsible (or typos Some I sale We re- al adder RETAILSTORESOPEN MON-SAT STORE 1310"B"E. Edinger STORE 674 El Camino Real 1 Santa Ana, CA 92705 #2 Tustin, CA 92680 IS, Retail, Warehouse Specializing in Systems P.O. Box 1 7329 Irvine, Calif. 9271 3 Direct Order Lines: (714) 558-8813 (8CX)) 854-8230 or (BOO) 854-8241 FOR INTERNATIONAL ORDERS: 1401 E. Borchard (714)953-0604 Santa Ana, CA92705 TWX:91 0-595-1565 Circle 264 on inquiry card. BYTE September 1980 353 The Supermarket for TRS-dO"^ /\CiCi"On ^^OrnpOnOriTS (and other computers, too] In stock now immediate delivery The VISTA V-80 Disk Drive System • 23%nnore storage capacity than TRS-80 • 120 day warranty • 40 track patch at NO CHARGE Single drive system $ 395.00 Two drive system $ 770.00 Four drive system $1450.00 Two drive cable $ 29.95 Four drive cable $ 39.95 The VISTA V-80 Expansion Module • Provides double density modification to your current Radio Shack interface (lets you format diskettes in either single or double density). • Increases storage capacity up to 204K bytes (on single 40 track drive). • Includes all hardware $239.00 software The VISTA Model II • Provides one, two or three drives. • Adds up to 15 million bytes of on-line storage. • 120 day warranty • Does everything Radio Shack's expansion system will do. ..for less! $1000.00 Single drive Expansion System $1550.00 Two drive Expansion System $2100.00 Three drive Expansion System $ 525.00 Additional drives alone The TRS-80 Printers Centronics 730... $945.00 7x7 dot matrix- '^IBL* 80 column ^i^ - -* Anadex DP8000... $895.00 9x7 dot matrix- 80 column VISTA Printer... $745.00 5x7 dot matrix- 80 column Cables $27.50 each Add On Drives MPI B51 40 Track, Double Densi1y-204K $275.00 MPI B52 Dual Head, Double Density-408K $375.00 Siemens FDD1 00-5 40 Track Double Density204K $275.00 Siemens FDD100-5 Flippy, records both sides $290.00 Siemens FDD100-8 8" Single Sided Drive $448.00 Other Products 1. VISTA Verbatim diskettes [hard or soft sector) Certified 40 track $ 38.95 2. 16K RPM upgrade kits, guaranteed for 120 days. PRIME PRODUCT $ 74.50 3. NEW! DOS + $ 110.00 4. LNW expansion bare board $ 66.95 5. H.C. Pennington book, TRS-80 Disk and Other Mysteries $ 18.95 6. DDT Disco-Tech disk drive timer $ 19.95 7. Cryptext (An Encryption Module) $299.00 The VISTA V-200 for Exidy , • Completely packaged system, tested and ready to plug in, includes: > power supply, two 40 track drives, case, controller, all cabling and . total CPM documentation. | • Storage capacHy from 400K to 1.2 meg. • System software-VISTA CP/M Disk Operating System and BASIC-E Compiler recorded on 5-1/4" diskettes. Price: Starting as low as $1199.00 CALL TOLL-FREE 800-854-8017 'TRS-30 is a registered trademark of Radio Shack The Vista Computer Company 1401 Borctnard Street • Santa Ana. California 92705 • 714/953-0523 354 BYTE September 1980 Circle 265 on inquiry card. TERMINAL DATA CORPORATION MODEL 1200 RS 232 DATA SPLITTER a vailable in kit form Model 1200K gives the terminal or micro- processor user a second interface for a printer, plotter, cassette or tape drive. It operates at any speed & isolates the two output devices from each other, while providing 2 RS-232 interfaces from the terminal or microprocessor. The kit consists of 3 RS 232 connectors, printed circuit board, all necessary components, enclosure, mounting hardware & assembly in- structions $67,00 write or call TERMINAL DATA CORP. 11678 Coakley Cir. RockvJIle, MD 20852 (301)881-7655 :pmiiii@M 8K BYTE STATIC RAM MODULE FOR THE G800; COMPATIBLE WITH THE MOTOROLA EXORcisef" BUS AND 2 KIT. TWO SEPARATE 4k ADDRESSES; EACH MAY BE USED AS RAM OR TREATED AS ROM. SWITCHES SET ADDRESSES AND CONTROL RAMiROM OPTION. ALL IC's ARE SOCKETED; EACH IC HAS A BYPASS CAPACITOR. ACCESS TIME: 450 NSEC. DIMENSIONS; HEIGHT 8.425IN. WIDTH 9.750 IN. THICKNESS .062 IN. SIGNALS: R'W. VMA OR VUA UUMPERI. (l2 STATIC RAM; LOW POWER 2102AN 4L OR EQUIVALENT. THE ALI688K COMES ASSEMBLED ANO TESTED WITH A ONE YEAR WARRANTY. PRICE $250 APPLIED LOGIC, INC P.O. BOX 328 JAMAICA, NEW YORK 114 15 (212) 459-4064 "EXORciser is a trademaik uf Mntoroln, Inc. S-100 A/D fllmiiiiTHiiimii niiiiiiiiiiififif • S-100 Bus Compatible A/D Converter • 12 Bit Accuracy • 16 Channel Analog Input • Programmable Gain Amplifier with Sample-and-Hold • High Quality Commercial/ Industrial Construction 2 and 4 Channel, 12 Bit D/A Boards also available. CALIFORNIA DATA CORPORATION 3475 out Cone jo Road, Suite CIO Newbury Park, California 91320 (805)498-3651 Circle 266 on inquiry card. Circle 267 on inquiry card. Circle 268 on inquiry card. -Diskettes = 8 inch'Soft/hard secio^: SngI sidC'Sngl dens $2.95 SngI sidB'dbte dens $3.55 SngI side-nevensbl $4.55 Dble sidC'Sngl dens $4.55 Dbie side -dble dens $4.90 5 inch'Soft/hand sector: SngI side '40 Tnk $2.75 Dble side '40 Tnk $4,05 SngI side' 77 Tnk $4.35 Visa/Mst.Chg/COD - call [20614884552 HARREX CORPORATION Media Sales Division P.O. BOX 249 Kenmone, Wash. 98028 PASCAL For programmers learning or desir- ing to learn PASCAL for the APPLE computer. LEARN BY EXAMPLE Three practical-useful PASCAL pro- grams (Text & Code) are now available on minidisk for only $55.00. Filecreate, fileupdate, and files earch will help you produce in just a very short time. Order today from: Personal Programs By Victor P.O. Box 60034 Sunnyvale, CA 94086 (CA Residents add $3.57 Tax) CUSTOM PROGRAMS UPON REQUEST 80X24 VIDEOTERM "^ 7X9 MATRIX DISPLAY FOR APPLE II® LOWER CASE W/ DESCENDERS i r HtGISIEnEO TKAOE 80 columns by 24 lines with easy to read 7x9 dot matrix, upper and lowercase with descenders using shift lock feature • IK firmware incorporates PASCAL and BASIC protocalls so user is not required to enter machine language programs or change PASCALS. Misc. info, or Gotoxy files • Compatible with all APPLE II peripherals so user won't need new software patches for future software products • Crystal controlled dot clock for excellent character stability • VIDEOTERM is the same size as t he Apple language card and power consump- tion is held to a minimum through the use of CMOS and lower power devices • Character set can be user de- finable up to a maximum of 128 symbols of 8x16 dot matrix font • Display control character mode and four standard display formats controlled by escape sequen- ces • Built in light pen capability • Inverse display mode • 50/60 HZ operation • Sockets on all IC's. PRICE:Withoutgraphic EPnOMS34S OPTIONS: Graphics EPROM line dwg.S2S ViDEO SWITCH PLATE. Inserts in case slot lo choose between APPLEII- and VIDEOTERM S12 MANUAL:S15 VIDEX 306D N.W. Thistle PI. Corvallis. OR 97330 Phone(S03)75B-0S21 9QS Circle 269 on inquiry card. Circle 270 on inquiry card. Circle 271 on inquiry card. SINGLE BOARD COMPUTER $99.50* with 6800 MPU. 6850 serial I/O, 2 6820 parallel I/O (32 lines), 512 RAM, socket for 2708, 2716, EROM. Interface modules for industrial control, data acquisition, lab Instrumentation, on 44 pin 4M!"x6'/2" PCB's. RAM, ROM, CMOS RAM/battery, A/D, D/A, Driver/Sensor, Serial I/O, Parallel I/O, Counter/Timer. IEEE 488 GPIB, floppy controller. *OEM (500 piece) price wiNii:i: 1801 South Street Lalayette.lN 47904 Phone (317) 742-6428 Corp. SAVE IS-SO% OF VOIR lUSli SI'ACE HUFF n PUFF • Bit compress your files with savings up to 50% • Cut your TP connect time by up to 50% • Z-80 code compatible with CP/M and CROMEMCO CDOS • Free 30 day money back guarantee HUFF n PUFF is available on 8" diskette, single or double density for $75. (California residents add 6% sales tax) J and S SOITWARK 2406 TORRIJON TL.VCi: C.VRLSKAI) CA. 92(Mm GET, Paid€ for using your Computer ^ FUN' EasN CES3i^ RUSH COUPON FOR ^^ ^ FREE FACTS ^G^^^ SPARETIME Send today to — DAR-B9 » _i^"-^' 31 10 Fulton Ave, Sacramento CA 95821 Circle 272 on inquiry card. Circle 273 on inquiry card. Circle 274 on inquiry card. H9 OUINCRS! Upgrade your video terminal mith one of these long overdue kits: GRRFIX — Graphical display capa- bilities assembled and tested $69.95. Hit $59.95. CURSOR CONTROL - R total of 8 functions assembled and tested $34.95. Hit $29.95. FLICK€R FR€€ — 4800 baud operation assembled and tested $79.95. Hit $69.95. All have q Pull 6 month njarrontv. NORTHUICST COMPUTCR SCRVICCS, INC. 8503 N.€. 30th Rvenue Vancouver, UJR 98665 S-100 VOICE The ARTICULATOR board allows you to record, store, and playback any vocabulary on your S-100 computer. Input speech is digitized by the ARTICULATOR and sent to the computer via an on-board port for storage at 1K to 2K bytes/sec. This data is then sent back from the computer to the ARTICULATOR for very high quality playback. On-board VOX switching minimizes memory storage requirements. PRICE - $319 A&T AVAILABLE NOW Quintrex, Inc., 9185 Bond Shawnee Mission, Ks. 66215 (913)888-3353 EVERY MONTH 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. CUTU^UT^R SHO!^t=tSR P.O. Box F-14 Titusville, FL 32780 (305)269-3211 MasterCharge or VISA orders only, Call TOLL FREE 800-327-9920 Circle 276 on inquiry card. Circle 277 on inquiry card. Circle 278 on inquiry card. 12" BLACK & WHITE LOW COST VIDEO TERMINAL $139.00 LIST Add $5 for shipping and handling Texasresidenlsadd5% sales tax. • Ideal for home, personal and business computer systems; surveillance monitors • 12" diagonal video monitor • Com- posite video input • Compatible with many computer systems • Solid-state circuitry for a stable & sharp pic- ture • Video bandwidth— 12 MHz ±3 DB • Input im- pedance— 75 Ohms • Resolution— 650 lines Minimum IN Central 80% of CRT; 550 LinesMinimum beyondcentral80% ofCRTrefEIARS.375 • Dimensions— 11.375" high: 16.250" wide; 11.250" deep (exclude video input con- nector) • Weight— 6.5 KG (14.3 lbs) net Use Master Qiarge/Visa or send money order. Micro Products Qnlimited P.O. Box 1525. Arlington, TX 76010 817/461-8043 Dealer inquiries welcome fiflPPLE ) SUPER SALE 16K Apple II CQQCnn or Apple II Plus ^// J.UU Apple Disk II w/controller Applesoft or Integer Cards $529.95 $159.95 Pascal Language Card $459.95 10 Megabyte Disk forApple $4695.00 DC Hayes Modems $339.95 Graphics Tablet $695.00 UCfiTRTI CamPLJTiR STORE P.O.BOX 1000 DESTIN FL 32541 ACROSS FROM RAMADA INN 904-837-2022 Credit Cards Accepted FOR SALE: Unusecd Polymorphic System 8813 with 32K Ram Memory with floppy disk drives, printer interface and Abern-Sopher Multiwriter in. System has Canadian import tax paid. Offers for complete system to; Bishop Management, #8-825 McBride Blvd., New Westminster, B. C, Canada. V3L5B5. (604) 525-8148. Circle 279 on inquiry card. Circle 280 on inquiry card. Circle 281 on inquiry card. clbis YOUR HEADQUARTERS FOR SALES • SERVICE • SUPPORT THE BEST NEW YORK AREA PRICES ON ALL OHIO SCIENTIFIC COMPUTERS - LOCAL USERS GROUP - BUSINESS AND PERSONAL SYSTEMS PROFESSIONAL BUSINESS SOFTWARE: Accounts Receivable Accounts Payable Wholesale Industry Distribution Grants Accounting System Payrol I ALSO AVAILABLE: "Eaton LRC 7000+ Plain Paper Printer. . .$356. *Okidata Microline 80 Printer- upper/lower case, graphics, any paper, software selectable print size 827. "Hazeltine 1420 Terminal 948. MASTERCHARGE £ VISA WELCOME Designers & Builders of information Systems, Inc. One Mayfair Road - Eastchester, New York \0707 (914)779-5292 (212)933-4170 Now on Disk Learn FORTH FORTH is a structured high level language that dramatically cuts program development time. You can expand the FORTH language by defining new operations and data types. FORTH programs arc compiled to reduce memory space and speed execution. tinyFORTH is a complete version of the powerful FORTH language tailored to (he TRS-80. The disk tinyFORTH sys- tem is a stand-alone operating system with FORTH, a text editor, an a.ssembler. and graphics. Learn FORTH on your own computer. The tinyFORTH user's manual contains hundreds of examples to teach you FORTH in a hands-on style. tinyFORTH for 16k level II TRS-80; Disk version and full documentation $49.95 Cassette version and full documentation S29.95 Documentation only (disk version) $14.95 All orders arc fully guaranteed. Add $1 .50 for postage and handling. Order with check, money order. Visa, or Master- charge. Write for a FREE booklet describing FORTH. The Software Farm Box 2304 Dept. A31 Rcston, VA 22090 micro-fTiQdness The Perfect Gift for every Computer 'Hut' Ao Acuroi micfO'Compucef chip ^otorged &000% tob^ome Q \