197801 Byte Magazine Vol 03 01 The Brains of Men and Machines

aD _— MINIFLOPPY Sil? Sick sverem Your computer system needn't cost a fortune. Some computer kits include little more than a mother board and a front panel, and you pay extra for everything else you need to: make an operating computer. SWTPC doesn't do it that way, so you can get your Southwest Technical 6800 Computer up and running at a bargain cost compared with most other systems. Itcomes complete at $395, with features that cost you extra with many other systems. The Extras You Get These extras include 4K of random-access memory, a mini-operating system in read-only memory, and a serial control interface. They give you 1) a considerable amount of working memory for your programs, 2) capability through the mini- operating system to simply turn on power and enter programs without having to first load in a bootstrap loader, and 3) an interface for connecting a terminal and beginning to talk with your computer immediately. Low-Cost Add-Ons Now that you have a working computer, you'll probably want to add at least two features soon, more memory and interfaces for needed accessory equipment. Memory for our 6800 is another bargain. You can get 4K memory boards for just $100 and 8K boards for only $250. Our interfaces cost little ul For just $35 you can add either a serial or parallel interface board. (And you won't have to buy several interfaces on a costly board to get just the one you want.) Peripheral Bargains Your computer is no good without at least a terminal for entering data and viewing computer output, and you will probably want a good method of storing programs and data. We offer you a line of high-quality peripherals at low prices. (You can prove this by just comparing prices.) Buy our CT-64 Video Terminal for only $325 and our CT-VM Monitor with matching cover for $175. Our MF-68 Dual Minifloppy costs just $995, complete with Disk BASIC and a disk operating system. For cassette storage our AC-30 Cassette Interface gives simple control for one or two cassette recorders. You can get inexpensive hard copy with our PR-40 Al- phanumeric Line Printer. We back up the 6800 system with low-cost software, including 4K and 8K BASIC. Compare the value you get with our computer and peripher- als before you buy. We think you'll find that SWTPC gives you more for your money in every way. —— 995 for the Dual Minifioppy ——— $250 tor the PR-40 Line Printer $828 for the C1-64 Terminal ____ $79.50 tor AC-30 Cassette Interface ‘Err coe pecnnis! _—_—. $175 for the CT-VM Monitor —— Or BAC # Exp. Date. H 219 W. Rhapsody, San Antonio, Texas 78216 $395 for the 4K 6800 Computer OrMc # Exp. Date! La don: Southwest Technical Products Co., Lid. Name ——____ Address __ ‘Tokyo: Southwest Technical Products Corp./Japan Zip City State sa —aLircle 102 on inquiry card. 1 can now have the industry’s the new Cromemco Z-2D computer. You can | fast because the Z-2D come ped with a 5” floppy di arnlich| more so And ever so much ly than Pvt cas~ e. you get our well- PU card the proven and sh li p handle 21 ¢ and d creat You can a ‘on this: Cromemco is committed to supplying quality rt fully as drive : DD) os. 21s ss 8495, Danenn, co or oe u 7 Circle 30 on inguiry card. = Ww . 7 i+ p 2 The easy way to get disk storage, FORTRAN IV, and other programming power Control up to: four 8” drives Here's a new disk controller and disk drive combination that will set you up for truly powerful disk storage. new controller is extremely versatile. You can use it with either our new 5” single disk drive or our 8” dual disk drive. In fact, the con- troller will interface up to three 5” or four 8” drives. That means you can have enor- mous disk storage since the new con- troller puts 92 kilobytes on each side of a5” diskette and 256 kilobytes on an 8” diskette. Recording is in soft- sectored 1BM format. FORTRAN IV AND MORE You can get still more Cromemco disk operation aids. For example, we also offer FORTRAN !V for our com- puter users. And as in so many things, we are the first manufacturer in the field to offer this advanced program for the Z-80 pP. Besides FORTRAN IV we also offer our special BASIC (14-digit precision), our Z-80 Assembler, and now an en- tertainment diskette with over a doz- en of our Dazzler® games. KEYBOARD CONTROL The new Model 4FDC disk con- troller (supplied in our Z-2D) is for our Z-2 computer or any S-100 bus computer using our Z-80 CPU card. You should also know about these other capabilities of the new con- troller: © {ts PROM-resident Disk Operating System (RDOS) gives you key- BYTE January 1978 Control up to three 5” drives ‘Cromemco 4?" Single 5” disk drive Dual 8” disk drive board control of your disk drive and also includes a bootstrap to load our powerful CDOS disk operating system supplied on all Cromemco diskettes. © The controller will interface your CRT terminal through its RS-232 serial port. May save you an I/O, © [thas 5 programmable interval timers. e It has vectored interrupts. © And it has an 8-bit parallel input port and an 8-bit parallel output port. LOOK TO THE FUTURE This new disk controller equips you for the future as well as for now, Not only can you now have very large storage, but the features of the controller and the standard IBM for- mat protect you from early obso- lescence. ‘CRT terminal interface USI circuitry 1 kilobyte PROM STORES/FACTORY This new card and the disk drives are in production and available, So contact your computer store or the factory today and you can have the power of FORTRAN IV and a large memory right away. PRICES Model 4FDC-K Disk Controller kit. Model 4FOC-W Disk Controller assembled Model WFD 5" single disk drive assembled Model PFO-K 8” dual disk deive kit . Model PFD-W 6” dual disk drive assembled Saess Disk drives are complete with power supply, case and cables. SOFFWARE Purchasers of Cromemco computers or drives may purchase software on 5” oF 6” diskettes as follows: 5” Diskette Ge Model__ Model FORTRANIV — FDF-S 2-80 Assembler FDA-S ‘16K BASIC FDB-S Dazztor® games FDG-S Price. ree $95 FDA-L FOB-L FOG-L $95 $95 Cromemco Specialists in comput and peripherals 2400 CHARLESTON RD., MOUNTAIN VIEW, CA 94043 © (415) 964-7400 Circle 30 on inquiry card, In the Queue BUTE January 1978 Volume 3 Number 1 Foreground 37 ADD MORE ZING TO THE COCKTAIL Hardware—Ciarcia 58 A FLOPPY DISK INTERFACE | Hardware—Allen 94 THE WATERLOO RF MODULATOR Hacks—Banks 161 MOUNTING A PAPER TAPE READER Mardware—Bryant Background u THE BRAINS OF MEN AND MACHINES: Biological Models for Robotics Robotics—Kent | 27 THE IRS AND THE COMPUTER ENTREPRENEUR Taxes and Business—Hughes 84 THE MOTOROLA 6800 INSTRUCTION SET Software—Jessop 86 A USER’S REACTION TO THE SOL-10 COMPUTER Product Review-Bumpous 108 THE SECOND WORLD COMPUTER CHESS CHAMPIONSHIPS Perfect Information Games—Jennings 122 STRUCTURED PROGRAMMING WITH WARNIER-ORR DIAGRAMS: Part 2 Software—Higgins 144 SIMULATION OF MOTION: Model Rockets and Other Flying Objects Modelting—Smith 150 A NOVICE'S EVE ON COMPUTER ARITHMETIC ‘Numbers—Ledder 162 NOTES ON BRINGING UP A MICROCOMPUTER Hardware—Libes Nucleus 4 In This BYTE 6 What Is This Phenomenon Personal Computing? 36 Letters 120 BYTE's Bits 136,160 Book Reviews 139 Clubs, Newsletters 165 Technical Forum: A Nate on Advances in Technology 168 What's New? 190 Classified Ads ote, | 192 BOMB q (Gy) . 192 Reader Service See ] VTE a outtanee moniniy tv BYTE Pubsianion ne, 70 Main i, Peterbarough NH O245B_ Ades ma excep ste senonons 10 aliove address’ hore (603! 924.7217 Aduret all editorial correspondence to the editor at the above addee. Unaceesrobie manuscriots will be teturned sl accompanied by sulfvcent firs class postage Not responsible for fost manu serois of photor Opinions expressed by the authors are nt necessardy those af BYTE. Address al subscriptions, change of J Searess, Form 3578, acd fulblimens complaint to BYTE Subscriations, PO Box $80, Martinvlle NJ OBB36. Second cats Gostage paid at Peterborough NH G248E and at additional mauling ollecesUSPS Publcation No. 102410. Canagan second flats regetration No. 9321 Subscriptions ave S16 for one year. $27 tor two years, and $99 for tree years sn the USA and «te pontessions. In Canada and Mexico, S17-50 ar one yenr, S22 ‘ar two years, and S46.50 (or three years S25 for a one year ubicripion by surface ea worldiwde Au detvery to selected areas at addivonal rates avaiable upon request. 25 far 9 one yeat subtcrption by are delvary ro Europe Single copy price $2.00 in the USA and «ts possessions, $2.40 mm Canada and Mexico, $3.50 + Europe, and $4.00 elsewhere. Formgn subtcriations and sales should be remitted im Unued States tunds Prirted in United States af Amarica Ente contents copyright 1977 by BYTE Publicaniany inc All rights reterved PUBLISHER, Virginia Pesctihe EDITOR IN CHIEF Gael T Helrners Ir PRODUCTION MANAGER, Judith Havey ADVERTISING DIRECTOR Debra Boudreau CIRCULATION MANAGER Gregory Spitefaden EDITORS Christopher P Morgan Blaise W Liffick ASSISTANT PUBLISHER Efizabeth CO-OF EDITOR Scott Morrow PRODUCTION EDITORS. Karen Gregory Nancy Salmon ADVERTISING Noreen Bardsley PRODUCTION ASSISTANT | Hurd Chery! CIRCULATION ASSISTANT Pamela R Heastin DEALER SALES Ginnie F Boudricaw TRAFFIC MANAGER Edmand O Kelly |r ART Wai Chiu Li U Etten Shamonsky BOOK PUBLISHER Christopher E Smith CONVENTION SUPERVISOR Elizabeth Alpaugh EXECUTIVE SECRETARIES fill Cattiban Patricia Clark Laura A Hanson RECEPTIONIST Jacqueline Earnshaw CLUBS AND NEWSLETTERS. David Wormak DRAFTING Douglas Glen ‘Stephen Kruse Lyne Malo Bill Moretlo Dorothy Shamonsky TYPOGRAPHY Custom Marketing Resources Inc Goodway Graphics PHOTOGRAPHY Ed Crabiree PRINTING Rumford Press NEW PRODUCTS EDITOR Daniel Fyistra ASSOCIATES Walter Banks Steve Ciarcis David Fytstra Portia Isaacson BITS INC Floyd W Retling ‘Medellin Stephens fim Teavisans Ronald Witzhe ADVERTISING SALES, SOUTHERN CALIFORNIA: Buckley Boris Associates Ine 912 South Barrington Suite 202 {Los Angeles CA 90049 (213) 826-1621 NORTHERN CALIFORNIA: Jules € Thompson Inc Hearst Building Suite 1111 San Francisco CA 94103 (425) 362-8547 BYTE January 1978 G | . 36.87" = GAMA SOM/SEC BOM/S5EC ————> som/sec O oe =: The compleat robotics experi- menter must have a thorough back- ground in biological models of be- havior and control, as noted in November’s editorial. With this issue, Ernest W Kent begins the first install- ment of a four part series with The Brains of Men and Machines, Part 1: Biological Models for Robotics. Dr Kent has provided readers with a thoroughly understandable _ intro- duction to a number of concepts essential to an understanding of the human brain and its simulation in robotic mechanisms. (Page 11) Can the experimenter who runs a small computer business deduct the price of additional memory for the computer? What kind of tax records should the small business keep? If you've been thinking of opening your own sma!l computer business, read Elizabeth M Hughes’ The IRS and the Computer Entrepreneur for the answers to these and many more tax questions. (Page 27} Last month, Steve Ciarcia described an inexpensive 8 channel digital volt- meter driven by a microcomputer. Read Add More Zing to the Cocktail in this month’s Ciarcia’s Circuit Cellar and find out how to add multiple ranges, AC and DC input capability and overvoltage protection to the basic circuit. {Page 37) When designing a floppy disk inter- face, the experimenter is faced with the continuous battle of hardware 4 BYTE january 1978 ty UU Cy versus software tradeoffs. David M Allen’s A Floppy Disk Interface balances the two extremes and shows you how to get a floppy disk system up and running. (Page 58) Paul M Jessop explores the func- tional organization of The Motorola 6800 Instruction Set showing Two Programming Points of View. (Page 84) Robert Bumpous provides A User's Reaction to the SOL-10 Computer in this issue. Learn a bit more about the Processor Technology computer’s design and assembly procedures in Robert's article. (Page 86) In what is probably the world’s simplest such design, Walter Banks describes a neat hack, The Waterloo RF Modulator, used to convey digit- ally generated video information from a computer to a standard television (Page 94) Cae ae mo On a battlefield for (intellectual) titans, the forces of black versus white met recently in Toronto. Who won? It was the artificial intelligence ex- perimenters, who demonstrated their nonartificial intelligence in construct- ing the programs entered in the Second World Computer Chess Cham- pionships, held last August during the IFIPS show. 16 programs met in logical conflict, with CHESS 4.6 con- quering all to win the current title. Turn to Peter Jennings’ article for asummary of the action. (Page 708) In Structured Programming with Warnier-Orr Diagrams, Part 2: Coding the Program, David A Higgins uses the program design completed in part 1 and demonstrates how to efficiently turn a diagram into a working BASIC program, {Page 122) Continuing the discussion of mo- tion calculated with a personal com- puter, Stephen Smith’s article Simula- tion of Motion: Model Rockets and Other Flying Objects turns to the need for simulating angular degrees of freedom and components of force along different directions. (Page 144) Are you uncertain as to how basic arithmetic operations such as mul- tiplication and division are performed on your computer? If so, Wayne H Ledder’s article A Novice's Eye on Computer Arithmetic may help you out. (Page 150) Using the RAECO paper tape read- er requires a mounting. See Jack Bryant's article on Mounting a Paper Tape Reader to see how this unit can be installed in an SwTPC 6800's cabinet. (Page 167) Building a homebrew system based on one of the many microprocessor chips available today is an interesting challenge. In Notes on Bringing up a Microcomputer, Sol Libes provides some general background information on the process of wiring and checking out a microcomputer based system. (Page 162) TARBELL SETS STANDARDS For Hobbyists and Systems Developers Sales to thousands of hobbyists over the past two years have proven the Tarbell Cassette Interface to be a microcomputer industry standard. Tarbell Electronics continues research and development to produce new and efficient components to fill hobbyists’ changing needs. TARBELL CASSETTE INTERFACE Plugs directly into your IMSAI or ALTAIR* Fastest transfer rate: 187 (standard) to 540 bytes/second Extremely Reliable—Phase encoded (self-clocking} 4 Extra Status Lines, 4 Extra Control Lines 37-page manual included Device Code Selectable by DIP-switch Capable of Generating Kansas City tapes also No modification required on audio cassette recorder Complete kit $120, Assembled $175, Manual $4 TARBELL FLOPPY DISC INTERFACE * Plugs directly into your IMSAI or ALTAIR® and handles up to 4 standard single drives in daisy- chain. Operates at standard 250K bits per second on normal disc format capacity of 243K bytes. Works with modified CP/M Operating System and BASIC-E Compiler. * Hardware includes 4 extra IC slots, built-in phantom bootstrap and on-board crystal clock. Uses eoeeecenee . WD 1771 LSI Chip. * 6-month warranty and extensive é Socupeniaton: Compatible Disc Drives Kit $190....... Assembled $265 Ask about our disc drives priced as low as $525. * Gold plated edge pins TARBELL © Takes 33 14-pin ICs or * Mix 40-pin, 18-pin, 16-pin and PROTOTYPE ic BO ARD © Location for 5 volt regulator Model 1010 * Suitable for solder and wire wrap © ALTAIR/IMSAI compatible Price: $28.00 For fast, off the shelf delivery, all Tarbell Electronics products may be purchased from computer store dealers across the country. Or write Tarbell Electronics direct for complete information. “ALTAIR is a trademark/tradename of MITS, Inc. 20620 South Leapwood Avenue, Sulte P ‘a Carson, California 90746 (213) 538-4251 Circle 105 on inquiry card. BYTE January 1978 Editorial What Is This Phenomenon Personal Computing? Articles Policy BYTL is continually seeking quality manuscripts written by individuals who care applying personal computer systems, designing such systems, or who have Anowledge which wilt prove uselul to ‘our readers. For w more formal descrip- tion of procedures and requicements, potential authors should send w self. eddressed, stamped envelope to BYTE Authors’ Guide, 70 Moin St, Peter: borough NH 03458. Articles which are occepted ure purchased with a rate of up ta $50 per magacine page, bused an technical quality and suitability for BYTE’s teadership. Each month, the wuthors of the two leading articles in the reader poll (BYTE’s Ongoing Monitor Box or “BOMB") are presented with bonus checks of $100 ond $50, Unsolicited materials should be occomponied by full ame and address, us well us return postage, ® By Carl Helmers People newly acquainted with the personal computer concept often are baffled by the idea, What does it mean to have and use a personal computer? Why are such computers all of a sudden becoming a prominent technological feature of our culture? In posing these questions and writing a short essay on the subject, a key purpose is to provide a brief overview and summary of personal computing for our newer readers, an exercise which it is neces- sary to perform from time to time. But the same exercise helps me to review and get a perspective on what is happening, and will, | hope, serve readers familiar with the field as an opportunity for reflection upon the marketplace as it is seen today. The very fact that | even have to take into account the existence of new readers is a revealing statement about the nature of the growth which has occurred in this field: when BYTE magazine was started by me, my partner Virginia Peschke and several associates in mid-1975, the starting point was essentially zero—the 250-odd subscribers to a newsletter technical publication | had been publishing for about a year. Now, as the 29th monthly issue of BYTE magazine goes to press, the November 1977 issue has just been delivered to over 105,000 people by subscription or sales in over 600 com- puter stores. As nearly as we can tell, we are still in the exponential growth stage of our circulation and have by no means saturated the prospects for interested readers. But this is only a reflection upon the industry as a whole. We could not support such a large circulation if it weren’t for the fact that there is a large and active group of manu- facturers who are producing and selling the products which our readers need and use as personal computing oriented people. Why? Ours is a culture of the mind. Western this field. So What Is the Current Personal Computer User Like? Scheduled for mailing January 15 1978 Is a new BYTE reader survey, Approximately 5000 readers selected at random from our subscription mailing list in December will receive a detailed question- naire concerning numerous aspects of personal computer use and enjoyment, as well as normal demographic data. A summary of the Statistics from this survery will be published in BYTE after the analy- sis is completed (as was done last year), If your name is picked, we'd appreciate your response to the survey, in the interest of creating an accurate statistical record of what is happening and has happened In © BYTE January 1978 civilization’s most prominent characteristic is that it salutes the individual thinking being (and indeed its generalizations to any sentient beings which may exist in the universe). The individual human mind is the temple from which all the appurtenances of modern civilization spring. Our market oriented civilization, more than any other, tends to recognize and promote the pro- ducts of the individual thinker, whether engineer, novelist, scientist, manager, student, capitalist, lawyer or a host of other specializations. To think is the standard human mode of operation, a part of the built-in equipment which has evolved in the species Homo sapiens. The fact that humans have personal values and resultant emotions and feelings is in no way inconsistent with this descrip- tion of humanity. If | know joy at some aspect of living, the fact that I can perceive such is often enhanced, if not made possible, by the operation of my mind. If | know sorrow at some other aspect of living, the act of knowing is made possible by the oper- ation of my mind. And of course, | gener- alize this: | am not the only active being on this planet, Every one of the readers of this essay is a unique variation on a similar theme. Into this milieu of a culture which celebrates and promotes individual achieve- ment as a way of life springs an achieve- ment of numerous individuals working in concert, the modern large scale integrated circuit, the computer on a chip. The result is today’s real life version of what might have been a science fiction scenario in past decades. The human mind from which this achievement springs is a portable, fairly efficient, and quite remarkable thinking machine, a product of countless millennia of evolution where the guiding standard has been success as an organism in a complicated environment. The human mind is intricately involved with the phenomenon which is the computer as we know it in this culture: the computer is a genuine manifestation of a hard to define science fiction concept, the “thought amplifier.” As a practical reality, it involves no technological extensions of biology, no mystical force fields, not one jota of built-in enmity for humans. The computer in all its uses is nothing more than an extension of the mind of its user. The programs which we all put into our com- puters are crystallizations of our own thought processes in a form which can be Continued on page 142 Look To The North Star HORIZON Computer. HORIZON ™— a complete, high-performance microprocessor system with integrated floppy disk memory. HORIZON is attractive, professionally engineered, and ideal for business, educational and personal applications. To begin programming in extended BASIC, merely add a CRT or hard-copy terminal. HORIZON-1 includes a Z80A processor, 16K RAM, minifloppy™ disk and 12-slot 5-100 motherboard with serial terminal interface — all standard equipment. ‘WHAT ABOUT PERFORMANCE? The Z80A processor operates at 4MHZ — double the power of the 8080. And our 16K RAM board lets the Z80A execute at full speed. HORIZON can load or save a 10K byte disk program in less than 2 seconds. Each diskette can store 90K bytes. AND SOFTWARE, TOO HORIZON includes the North Star Disk Operating System and full extended BASIC on diskette ready at power-on. Our BASIC, now in widespread use, has everything desired in a BASIC, in- cluding sequential and random disk files, formatted output, a powerful line editor, strings, machine language CALL and more. EXPAND YOUR HORIZON Also available— Hardware floating point board (FPB); addi- tional 16K memory boards with parity option. Add a second disk drive and you have HORIZON-2. Economical serial and parallel |/O ports may be installed on the motherboard. Many widely available 5-100 bus peripheral boards can be added to HORIZON. QUALITY AT THE RIGHT PRICE HORIZON processor board, RAM, FPB and MICRO DISK SYS- TEM can be bought separately for either Z80 or 8080 5-100 bus systems. HORIZON-1 $1599 kit; $1899 assembled. HORIZON-2 $1999 kit; $2349 assembled. 16K RAM—$399 kit; $459 assembled; Parity option $39 kit; $59 assembled. FPB $259 kit; $359 assembled. Z80 board $199 kit; $259 assembled. Prices subject to change. HORIZON offered in choice of wood or blue metal cover at no extra charge. Write for free color catalogue or visit your local computer store. NortH SitaR *& COMPUTERS 2465 Fourth Street « Berkeley, California 94710 * (415) 549-0858 Circle 78 on inquiry card. BYTE January 19787 Introducing Apple II. You've just run out of excuses for not owning a personal computer. : Clear the kitchen table. Bring in the color TV. Plug in your new Apple I and connect any standard cassette recorder/player. Now you're ready for an evening of discovery in the new world of personal computers. Only Apple II makes it that easy. It’'sa —_ 7 comple ready to use computer, not a kit. At $1298, it includes video gra- phics in 15 colors. It includes 8K bytes ROM and 4K bytes RAM—easily expandable to 48K bytes using 16K RAMs (see box). But you don’t even need to know a RAM froma ROM to use and enjoy Apple Il. For example, it’s the first personal computer with a fast version of BASIC permanently stored in ROM. That means you can begin writing your own programs the first evening, even if you’ve had no previous computer experience. The familiar typewriter-style keyboard makes it easy to enter your instructions. And your programs can be stored on—and retrieved from— audio cassettes, using the built-in cassette interface, so you can swap with other Apple II users. ; You can create dazzling color displays using the unique Oe ee hics Belen inds in Apple A a rite simple programs to display beautiful Taierdoccopic designs. Or invent your own games. Games like PONG—using the game paddles. supplied. You can even add the dimen- sion of sound through Apple II's built-in speaker. But Apple Il is more than an advanced, infinitely flexible game machine. Use it to teach your children arithmetic, or spellin; for instance. Apple makes learning fun. Apple I can also manage household finances, chart the stock market or index recipes, record collections, even control your home environment. Right now, we're finalizing a peripheral board that will slide into one of the eight available mother- board slots and enable you to com; music elec- tronically. And there will be other peripherals announced soon to allow your Apple II to talk with another Apple II, or to inter- face to a printer or teletype. ; pple II is designed to grow with you as your skill and experience with computers grows. It is the state of the art in personal computing today, and compatible upgrades and peri- pues will keep Apple II in the fore- nt for years to come. rite us today for our detailed brochure and order form. Or call us for the name and address of the Apple II dealer nearest you. (408) -1010. Apple Computer Inc., 20863 Stevens Creek Boulevard, B3-C, Cupertino, i 6014. Bh Apple I™ is a completely self-contained computer system with BASIC in ROM, color graphics, ASCII keyboard, light- weight, efficient switching power supply and molded case. It is supplied with BASIC in ROM, up to 48K bytes of RAM, and with cassette tape, video and game I/O interfaces built-in. Also in- cluded are two game paddles and a demonstration cassette. SPECIFICATIONS © Microprocessor: 6502 (1 MHz). * Video Display: Memory mapped, 5 modes —all Software-selectable: + Text—40 characters/line, 24 lines upper case, + Color graphics—40h x 48v, 15 colors + High-resolution graphics—280h x 192v; black, white, violet, green _ (12K RAM minimum required) + Both graphics modes can be selected toinclude 4 lines of text at the bottom of the display area. + Completely transparent memory access. All color generation done digitally. * Memory: up to 48K bytes on-board RAM (4K supplied) » Uses either 4K or new 16K dynamic memory chips + Up to 12K ROM (8K supplied) ¢ Software + Fast extended integer BASIC in ROM. with color graphics commands + Extensive monitor in ROM “1/0 + 1500 bps cassette interface + 8-slot motherboard + Apple game I/O connector + ASCII keyboard port + Speaker - Composite video output Apple Iis also available in board-only form for the do-it-yourself hobbyist. Has all of the features of the Apple II system, but does not include case, keyboard, power supply or game paddles. PONG is a trademark of Atari Inc. *Apple Il plugs into any standard TV using an inexpensive modulator (not supplied). Order your Applell now. from any one of the following authorized dealers: ALABAMA Computerland 3020 University Or. 8.W Huntsville 539-1200 ALASKA The Aipha Corporation 300 W Int] Auport Ro. Anchorage 279-1316 Team Elecironics Anchorage 276-2823 Anchorage 272-4823, Faubanks 456-4157 ARIZONA Byte Shop Tempe 694-1129 Phoenix 942-7800 Tucson 327-4576 CALIFORNIA SNC Bester as Long Beach 598-0444 Byte Shop Citrus Heights 961-2983 Palo Allo 227-8080 Pasadena 684-3313 San Jose 377-4685 San Mateo 341-4200 ‘Sana Ciara 249-4221 Walnut Creek 993-6252 Computerlend EiCerrita 233-5010 Hayward 538-4080 Inglewood 776-8080 Mission Viewo 770-0131 San Diego 560-9912 San Feancisco 545-1592 Thousand Oaks 495-3554 Tustin 544-0542 emputer Components S848 Sepulveda Blvd. Van Nuys 786-7417 Computer Country S08 E. Tst. St Tustin 838-4770 Computer Playground 6789 Westminster Avenue Westminster 898-8330 Computer Store 1093 Mission Si. San Francisco 431-0680 ‘The Computer Store 820 Broads Sama Moni 451-0713 Electric Brain 3038 N Cedar Ave. Fresno 207-8479 Home Entertainment Emporium 2100 Sepulveda Manhattan Beach 546-2501 Raindow Computing, Ine. 10723 Wine Oat Granada Hil 360-2171 ‘Strawberry Electronics, 2 Glen Way 9 Belmont $95-023 COLORADO Byte Shop 3464S Acoma St Englewood 761-6232 ‘Team Etecironies Boulder 447-2368 Colorade Springs 596-5566 Fort Collins 484-7500 Grand Junction 245-4455 Gresley 356-3800 Longmont 772-7800 Pueblo 545-0703 CONNECTICUT Camputeriand 2475 Black Rock Turnpike Fairhela 374-2227 Wiser (oats 627-0108 DELAWARE Computertand Kirkwood Highwa Newark 73 10 BYTE famuary 1978 FLORIDA Byte Shop FA Lauderdale 561-2983 Miami 264-2883, GEORGIA DataMan. tne. 3001 N. Fulton Drive Allante 233-0532 HAWAI Real Share 190 S. Xing Steet #880 Honolulu "536-1041 ILLINOIS ‘Computeriand Arlington Heights 255-6488 Wiles 967-1714 Oaklawn 422-8080 Dats Domain 1612 € Algonquin Ra. Seine 397-8700 Evanston 328-6800 ‘Team Electronics Carpentersvile 428-6474 Decatur 877-2774 Galesburg 344-1300 Moline 797-8261 Peoria 692-2720 Rock island 788-9595, Rocktoré 399-2577 Schaumburg 882-5864 Springtield 525-8637 INDIANA ‘Tue Data Domain Fort Wayne 484.7611 Bloomington 334-3607 West Lalayette 743-3955 Indianapoks 251-3139 The Home Computer Center 2S E. 62nd st ‘Indianapous 251-6800 Dubuque $83-9195 lowa City 338-3681 Sioux City 252-4507 Sioux City 277-2019 Wetetloo 235-6507 Yiao Mawes tn Bes Mawes a0 1447 KANSAS Barney & Associates 425 N. Broadway Prisourg 231-1970 ‘Team Electronics Garden City 276-2911 Hutchinson 652-0632 Lawrence 841-3775 Manhattan 538-4836 Saba 827-9364 Topeka 287-2200 ‘Wichwla 685-8826 Wiohita 942-1415 Wachita 682-7559 KENTUCKY terland 8138. Lyndon Lane isvite 425-8308 ‘Tha Data Domain Lexingion 233-3346 Louisville 456-5242 MARYLAND TOG Fresrck oad Rockwile 948-7676 Computers, ‘3A Allegheny Ave. Towson 674-4742 MASSACHUSETTS ler Stove, Inc nige Street Burlington 272-8770 MICHIGAN Team Electronics Escanaba 786-3911 Menominee 854-2213 MINNESOTA ‘Team Electronics Minnetonka 544-7412 Edina 920-4817 Eden Prairie 941-8901 SGemidy 751-7880 Yallmar 235-2120 St Cloud 253-8326 Owatonna 451-7248 Hibbing 263-8200 Yugnia 741-5919 St Anthony 789-4368 ‘West St. Pavl 451-1765 Minneapoks 377-9840 St Paul 227-7223 St Cloud 251-1335 Minneapolis 889-3288 Manneapolis 378-1185 Maplewood 777-3737 Mankato 387-7937 Eveleth 749-8140 St Paul 636-5147 MISSOURI tectonic Components, nl 1306-8 Sou Hwy 6: Colwmba 443-5225 Team Eleciromes Mall 301 Stadium Btvd, Cobumbia 445-4496 MONTANA, ‘Computers Made Easy 415 Morrow Bozeman 586-3065, ‘Team Electronics Great Fas 852-3281 Missoula $49-4419 NEBRASKA Team Electronics Grand Isfand 381-0559 Lincoln 435-2959 Omang 397-1665 ‘Omaha 333-3100 Nortakk 379-1161 North Platte 534-464 NEW HAMPSHIRE ‘Computermart 170 Wain Street Nasiiua 883-2386 NEW JERSEY Compuleriand 2 De Har Street Morristown $39-4077 NEW YORK Gomputertand Bulfato 836-6511 Ithaca 277-4888 ‘Computer Mant of N.Y, 118 Madison Ave. New York 686-7923 Co-op Electronics $148 Main Street Glarence 634-2193 NORTH CAROLINA Byte Shop 1213 Hillsborough St Raleigh 833-0810 Computer Room 1729 Garden Terrace Crarlatte 373-0875, Rom’ & Ram's rabies Vay Mal Raleigh 761-0003 NORTH DAKOTA Team Electronics Bismarck 223-4546 Faigo 282-4562 Grand Forks 746-4474 Minot 852-3281 ‘Williston 72-7631 OHIO Somputaand 1304 SOM Cen hiayheld ets, reo ‘The Data Domain Daylor Cincinnati 2230 961-6733 48 OKLAHOMA Bis, Bytes & Micros. 1186 N. Macarthur Bid. Oklahoma City 947-5646 High Technotox 1020 W. Wils Oxia iy 843-9667 sam Electronics. ise vd Norman 329-3456 Oklahoma Cy 634-3357 Oklahoma City 848-5573 Stillwater 377-2050 Tulsa 633-4575 Tulsa 262-5751 Yokon 373-1994 OREGON Team Electronics Bend 389-8525 Canby 265-2539 Salem 3643278 PENNSYLVANIA Computer Mar of PA Fou Ne 202 King of Prussia 265-2580 SOUTH DAKOTA Team Electronics Prerte 224-1881 Rapid City Sioux Falls Sioux Falls Sioux Falls Watertown (408) 996-1010 EURAPPLE 343-8363 396-3730 399-1421 339-2287 886-4725 TEXAS Byte sh S31 Fone Houston 977-0664 Computerland Houston 997-0909 Austin 452-6701 Computer Shops. Inc, 13933 North Coniral Dallas 234-3412 The Somoue Shop 6812 San Pedi San Anfono 828-0869 Computer Terminal 2101 Myrtle St El Paso. 532-1777 The KA Computer Store 1200 Majesty Orve Dallas, VIRGINIA ‘The Computer Hardware Store 816 Franklin St Aiexandiia 548-8085 Home Computer Center Virginia Beach 340-197, Newport News 595-1955 Tunderville Elactronies 0x Tiberville 696-8926 WASHINGTON Toam Electronics 23 W. Yakima Yakima 453-0313 WASHINGTON, D.C. Seroatown Computer Store 3 Washington, D.C. 382-2127 WISCONSIN ‘Team Electronics Eau Glaire 834-0328 Eau Ctawre 834-1288 Madison 244-1999 Racine 554-8505 ‘Sheboygan 458-8791 Rhinelander 369-3900 LaCrosse 788-2250 ‘Wausav 842-3364 ‘Milwaukee 672-7600 Manitowoc 684-3393 Milwaukee 354-4880 Oshkosh 233-7050 WYOMING — Electronics se ges Casper 235-6691 CANADA Future Byte 2274 Rothland Montreal, Que. 731-4638 AUSTRALIA Somputrand 22-58 Chreneo ge Sydney, NSW 29-3-153, applic computer inc: 10260 Bandley Drive Cupertino, California 95014 European Operations of Apple Computer, Inc. 2031 Byron Street Palo Alto, CA 94301 (415) 964-7020 Circle 4 on inquiry card. The Brains of Men and Machines Part 1: Biological Models for Robotics Ernest W Kent, Associate Professor Dept of Psychology The University of IMinois at Chicago Circle Chicago IL 60680 The idea of a machine that thinks like a man has always fascinated us. If we talk about substantial improvements in processor design, it is relegated to a few technical journals, but if we talk about robots, or write stories about computers with person- alities, or make movies about HAL, everyone gets interested, and computer buffs stay up all night trying to figure out how to make their machines behave like that. An artificial “intelligence,” in the sense in which we apply that term to our own thought processes, has been a recurring theme dating back to antiquity, despite the fact that no such machine has ever existed. | don't know why this is so, perhaps it springs from a desire to understand our own thoughts, or perhaps the human race is just lonely. We keep hoping for dolphins and Martians to start talking to us too. Whatever the reason, the idea is a potent one, and an enduring source of interest. Why then don’t we build computers that think like men? Well, people have certainly tied, and some very elegant software has been created towards that end, but the results have always been frustratingly limited. You have all heard the old adage that a computer to equal the human brain would require a machine the size of the Empire State Building with the electrical output of Niagara Falls to power it, but that was always just an excuse. Aside from the fact that whoever coined that notion didn't have any idea of what a brain-like computer would require, the fact is that we would have built it anyway, if we’d known how. Moreover, when thal guess was made, we were making computers out of 12AX7s, and it’s a long way from the 12AX7 to the 2-80. We would certainly build that machine loday, if we knew how. What then is the problem? Our big fast machines can do elegant and complex mathematics, even proofs, far beyond our own powers, yet we have the greatest difficulty making them display even the slightest degree of common sense. The System 370 can do amazing things with numbers, but it wouldn’t have the intelligence to duck if you swung a club at it. A frog could do better at dealing with its environment. | assure you that the problem has nothing to do with any mysterious properties of the brain. If we have learned anything about the brain, it is that it is a machine. A complex machine to be sure, but a machine nonethe- less. This notion frequently upsets people; they are bothered by the suggestion that they might be ‘only a machine.” | think that this is the wrong interpretation. The stalement that the brain is a machine does not mean that it is “only” a machine in the sense of the simple machines of limited ability that we have produced, Rather, it isa statement that extends our concept of what amachine can do. It does not denigrate what the brain can do. Of course, it raises the possibility that we can design a machine that thinks like a man, with all of the attendant problems of philosophy and theology that that raises. One could take refuge in the notion that brain and mind may somehow be different, but the evidence is that when the brain is manipulated experimentally, all of our mental processes, our sensations and percep- tions, our feelings and emations, our in- tellectual processes, our memories, even our states of consciausness are manipulated too. The evidence suggests that this manipulation BYTE January 1978 a 42 BYTE January 1978 is predictable and occurs in the same fashion in all individuals. Why are we having so much trouble making our computers behave in brain-like fashions if both are machines and both information processing machines at that? | think the answer is that we are trying to make a wrench do a screwdriver’s job. What | mean is that while all information proc- essing machines may theoretically be capable of imitating all others, Turing didn’t say that all had to be built to handle all problems with equal ease. In point of fact, the brain’s architecture is quite different from that of computers as we customarily build them, and different in ways that are very instruc- tive with regard to the problem of building a “thinking machine.” The brain and the computer have both developed in an evolutionary manner, with “survival of the fittest’”” determining what features were retained and what were dis- carded. The differences in their designs arise from the fact that nature and computer engineers have different notions of what constitutes “‘fittest."" There are two aspects to this difference: the nature of the prob- lems the machine is required to solve, and the nature of the hardware available to build the machine. The successful brains, the ones whose genes contributed to the next genera- tion, were the ones that had good designs for solving problems like recognizing and avoid- ing dinosaurs, and recognizing and catching frogs. Ability at higher mathematics was never a very important criterion in deter- mining successful brain design, and our poor brains get quickly strained when they're required to do much of it. Computer design was judged from the beginning in terms of its success at mathematical function, and as a result they are very good at it, but very bad at catching frogs. The kind of hardware available to com- puter engineers and to organic evolution was also different, and in part determined the differences in architecture of successful brains and computers. Although the logic gate and the neuron have a great deal in common as we shall see, some of their differences turned out to have far-reaching consequences. The brain never had speed on its side, neurons operate in milliseconds not nanoseconds, but it never lacked for quan- tity. (You want million bit bytes and ten thousand legged gates? Sure, how many trillion?) The computer engineers on the other hand were limited in quantity by the expense and difficulty of assembly of their components, which dictated designs that were hardware conservative. This was com- pensated by using the speed of electronic components to substitute for quantity. Thus, our computers emphasize small bytes and few registers, but achieve high data thruput with iterative reuse of these components at great speeds. Bus oriented design and other hardware conservative adaptations arise from these same considerations. In contrast, parallel multiprocessor de- signs with hierarchical organization, which the brain uses with wild abandon, are only seen in the most primitive form in our current computers and computer networks. The brain also has no compunctions about freely mixing digital and analog computing elements, using each to best advantage where needed. Thus, the brain and the computer have cach found a design best suited to the problems they are required to solve and the hardware available, albeit big brains can do some computer-like functions, poorly; and big computers can do some brain-like func- tions, poorly. Curiously enough, both the brain and the computer seem to have settled on a single basic organization whether the device is large or small. We all know how a computer works in principle, although different machines differ in detail. The processor, the bus, the clock, memory, the IO interface, all are arranged according to the same basic plan in large machines and small. Similarly, the brain of the white rat in my laboratory is of the same design, basically, as the brain reading this page. All the same parts are included in both, and hooked up in the same way. The differences are in capacity and relative development of the parts. Brains are even more similar to one another than computers. What | am suggesting is that the com- puter has developed an architecture that is optimized for logical and mathematical problems, but that that is not an optimal architecture if the problem is to display basic common sense, whether it can do Fourier transforms or not. Thus, our machines as presently configured are terribly inefficient at the kinds of problems brains. solve easily, and prodigious feats of program- ming, vast amounts of memory and all the speed that can be mustered give us only the most trivial results. | am not going to suggest that we try to build a hardware replica of the brain. We don’t have the hardware or the knowledge yet, | would like to suggest however that if we are interested in approaches to a science of robotics, it would be very instructive to examine the only model of an intelligent machine that is available to us, and to try to identify principles of operation that could Is your career growing as fast as ours? EARNINGS PER SHARE (In Dollars) 288 NETSALES 9547 (Millions ot Dol.ars) New Products Engineers (Analog and Digital) Your responsibilities will in- clude new product introduction of state-of-the-art processors, peripherals and controllers to our Systems Integration Divi- sion. A BSEE degree or the equivalent is required witha minimum of 3 or more years of related experience. Diagnostic Programmers You will design, code and debug assembler language Programs for fault isolation, to the chip level, in digital sys- tems. You will also write func- tional level system exercisers for stand-alone and disc-based real-time operating systems. A technical degree or the equiv- alent experience is needed, together with a thorough under- standing of digital system hardware. Hardware trouble- shooting experience and 3 or more years’ programming experience, preferably in diagnostics is very desirable, especially with strong assembly language skills. 1973 1974 1975 1976 1977 (1977 Fiscal Year) Test Engineers You will be responsible for PCB test engineering support for digital products such as CPU's, memories and options. Experience is required in solving engineering problems. as they relate to test equipment, diagnostics, test philosophy and component fault isolation. You will also initiate and imple- ment improvements to the testing process and equipment, and provide coordination for the introduction of new prod- ucts into production. A BSEE degree and two or more years" experience in PCB test or Test Equipment Design. Manufacturing Engineers You will be responsible for providing floor support in the PCB assembly area. 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To apply for one of the above positions mail your resume to John Prendergast, Data General Corporation, Route 9, Southboro, MA 01772. Data Generalis an equal opportunity employer, M/F. qd, DataGeneral Cuele 31 en inquiry card BYTE Janwary 1978 14 BYTE January 1978 AXONS FROM OTHER NEURONS — SS. Bopy - DENOR TES r INPUTS 7 aroun wie oee AKON TERMINALS te axon ouTPUTS Figure 1: The parts of the neuron, the brain's basic “gate.” Flow of information through this gate is roughly from feft to right. Outputs are digital pulse streams transmitted through the axon and its branches to inputs of other neurons. Inputs are signals from other axons, which are summed by an analog process which weights various sources and fires an output pulse when a threshold is reached. be put to good use with the kinds of hardware that we do have. This is a parti- cularly appropriate time for such an exer- cise, since the hardware revolution has freed us to a degree from some of the original constraints upon computer design, and the growth of the computer hobby community has provided us with a group of cager experimenters who don’t have a large invest- ment in standard approaches, or a require- ment to produce commercially useful business machines. Finally, our under- standing of the operation of the brain has undergone something of a revolution in the last ten years, and we are in a much better position to discern the outlines of its archi- tecture than we were when the computer was born, The time is right, the means are at hand, all we need are the geniuses in the basement workshops. Lam not going to tell you how to build a machine to work like a brain, because | don’t know how. What | propose to do is to tell you, in terms of computer concepts, how a brain works. You supply the ideas from there. It is generally very difficult to explain brain operation to the layman, be- cause he doesn’t have the necessary concepts readily available. | have found, however, that it is very easy to explain brain operation to computer people because it can be translated into terms and concepts with which they are already familiar. If you can understand digital and analog electronics, you can understand in principle, if not in detail, how your brain works. You don’t have to under- stand neurophysiology, neuroanatomy, neuropharmacology, and physiological psychology, (Well, maybe a little bit, but I'll try to keep it painless.) First, you have to get a picture of the basic unit of brain structure. This is calied a neuron. It is a cell like all the others in your body, but it is specialized for information processing. You can think of it as perform- ing much the same function as a logical gate in a digital machine, or an operational amplifier in an analog machine. In fact, itis a very versatile device and can do either or both jobs. The brain uses neurons, billions and billions of them, to do everything it does. Let's look at the diagram of a neuron in figure 1. The output of the neuron appears on the long thin part labeled axon. Think of the axon as a wire. The brain uses them for transmitting information over dis- tance, The difference is that this wire trans- mits only pulse streams, not DC levels. It's a Meet The North Star Family THE NORTH STAR S-100 FAMILY—four high perform- ance products at attractive low prices. Our boards are designed for use in the North Star HORIZON computer and other S-100 bus computers using 8080 or Z80 proces- sors. Visit your computer store for a demonstration, or write for our free color catalog. 16K RAM BOARD No other S-100 bus memory can match the performance of the North Star 16K RAM at any price. 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NorATH SiaR %& CoMmPUTERS Circle 78 on inquiry card. 2465 Fourth Street - Berkeley, California 94710 » (415) 549-0858 BYTE January 1978 15 EXCITATORY INPUTS wwpur iow ONE ONE & SHOT I ] O snot [-——~<) inntatroRY npurs one one > SHOT q I g oNér /——<a cELL Boo Sno SENORITE axon anaLos Aiucocw SUMMING CIRCUIT AXON \ | => shor + > neel \ Fy >_> Figure 2: An equivalent circuit for the neuron, illustrating some of its important properties as an analog and digital device. This model should be compared to the information in figure I. 16 BYTE January 1978 digital wire. All the pulses are always the same height and duration, and can be thought of as binary bits. Only ones and zeros are allowed. Now look at the part labeled axon hillock. That's like a Schmitt trigger. It puts a pulse on the axon whenever the analog voltage in the part labeled cell body crosses a preset threshold value. When- ever this occurs, the voltage in the cell body is reset to the baseline or initial value. This cell body voltage is raised toward the Schmitt trigger’s threshold, or dropped away from it, by the action of pulses impinging on the cell body from the axons of other neurons. The place where an axon meets a cell body is called a synapse, and it only transmits in one direction. Think of it as a diode. Now a synapse may be positive or negative. That is, a pulse at a given synapse may either add to or subtract from the cell body voltage. This is a function of which synapse receives the input, not the nature of the pulse (just like the little inversion circles on logic gate inputs). Remember however that the voltage in the cell body is an analog voltage and is performing an algebraic sum of the inputs. Moreover, the inputs may have different weights. The ones furthest from the axon hillock have the least effect, the ones nearest to it have the greatest effect. Weighting may be reduced greatly by placing the input far out on an extension of the cell body called a dendrite. The effect of an input outlasts the pulse that produces it, so that inputs which do not arrive synchronous- ly in time may still sum within brief time limits. Think of it as a pulse stretcher at each input coupled with a time constant in the cell body. The effect of the finite time constant is to give each input pulse a temporal weighting (ie: the more recently arrived pulses have a greater weight in the sum). When the inputs to the cell body have summed past threshold at the axon hillock, and a pulse has been placed on the axon asa result, we say that the neuron has “‘fired."” An equivalent circuit (for our purposes) of the basic neuron is shown in figure 2. If you study figures 1 and 2 for a moment, you will see that the neuron has digital inputs, which are converted to analog values and operated on algebraically in an analog fashion. The result is then converted back to digital form for transmission. Now this is a very powerful tool. It can act as an AND gate (coincidence of several equally weighted inputs required to reach firing threshold), an OR gate (any PROTECT UN PROTEC ROUNDARY Compuler Product from Prost: Sonex Sretcacctss “7 MOSEL RANTS - THE PROBLEM SOLVING 16K STAIIG RAM Featuring: Bank Select « Memory Protect * Segment Disable * Low Power Consumption - 1.3 Amps. * SOL Phantom « Fully Buffered * 4K Boundary Addressing See the Complete < : Call Us For The Problem Solver Systems Sine - Dealer Alearest You... atUYourLocalDealer i / (213) 888-1714 BOLD LEERUNE AVE.- SUITE A - CARLGH PRA, CA T3O4 Circle 90 on inquiry card. fo) CORTEX: (oe) LiM@tc SYSTEM THALAMUS: MESENCEPHALON DIENCEPHALON HYPOTHALAMUS: CEREBELLUM ‘SPINAL coRD Figure 3: The brain as it appears anatomically. Above: a view of the brain from the left side. Below: A view from the left of the inside of the brain shown cut in half down the center line. The basal ganglia (striatum) which do not show here would be on either side of the thalamus. Motor region Senuity tegen tec® 29 Honk Temporal lobe “erebellum Specifications: The Human Biocomputer Cell Count: 15 billion (all present at birth) ‘Structural Completeness: 50% at birth, 100% at age 15 years Energy Requirements: 20 watts, biochemically fueled Sugar Consumption: 1 teaspoon per hour Biood Flow: 1.5 pints per minute (20% of total body requirement) Oxygen Consumption: 45 cc per minute (STP} (25% of total body requirement) This illustration was supplied by the author. 1B BYTE January 1978 of several inputs can drive the cell past firing threshold), or any of a variety of other functions (NAND and NOR can be achieved by cells with a resting potential above firing threshold, and inhibitory inputs). When you consider that one or more of the inputs to the cell can be feedback from its own axon, and that an average neuron may have ten thousand inputs, you begin to appreciate the possibilities. It can integrate and differ- entiate and do other useful functions by virtue of feedback and analog operation. No one would try to design a very large system out of gates this complex unless someone finds a way to make them in quantity on a chip. Consideration of their operation however reveals some important considerations of brain architecture. First, although neurons can be synchronized by simultaneously driving them with an over- riding input, they are normally asynchro- nous devices. The system can use lacal “clocks” where they are useful, but it doesn’t have a system clock. This permits an interesting development. In synchronous systems, information can only be coded in terms of which lines are active. If you want to indicate on or off status of some condition, you put a zero or one on the appropriate line. But if you want to indicate a numerical value greater than one, you have to do it by coding it as the activity, or lack of it, simultaneously on several lines. For example, we represent numbers by the bit pattern in a byte on the data bus. Now the brain can, and in several instances does, function in this mode. We refer to it as “place coding’ because the information is contained in the location of the incoming signal. However, because it does not have to maintain synchronization, the brain can also encode information in terms of the frequency of arrival of pulses on the axon. We refer to this, obviously enough, as “frequency coding." Examina- tion of the model circuit {figure 2) for the neuron reveals that the greater the positive input drive to the cell body, the more quickly the analog voltage will reach thresh- old, and the more quickly a new pulse will be placed on the axon after the reset following the preceding pulse. This means that it is very easy to use frequency coding to indicate the magnitude of the summed input activity. Due to the “‘pulse stretchers” at the inputs to the neuron, and the time constant of the cell body, pulses that are sequential on the axon can sum with one another to produce a greater analog voltage. This voltage is proportional to the frequency of the incoming pulses, and this achieves decoding of frequency coded input back to the analog mode, High performance, cost effective products for your microcomputer. The Extensys FOS100 Floppy Disk System provides a high performance floppy disk system based upon multiprocessors in a multiuser environment. The FOS100 accomplishes this through a completely integrated hardware and software system. 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Delivery is STOCK to 15 days upon receipt of order, with shipping and handling prepaid in the continental United States. corporation Extensys Corporation 380 Bernardo Avenue Mountain View, CA 94040 (415) 969-6100 20 BYTE January 1978 Interaction of inputs from different axons is termed “spatial summation,” and interaction of sequential pulses on the same axon is termed ‘temporal summation.” One of the interesting things the brain can do with this capability is to use both place and frequency coding simultaneously on the same line. Another advantage is the ability to represent very large numerical quantities with what might be called a “temporal byte,” or integration over a brief time period, of a single input line. As an example, consider the way the brain encodes sensory information from your skin. The type of sensation (ie: heat, cold, pressure, etc) as well as the location of the sensation is place coded. That is, what you feel is a function of which line is active. The magnitude of the sensation, how much you feel, is frequency coded on the same line. Thus, the brain structure receiving the infor- mation can determine the type and location of the stimulation with a “spatial byte,” (place code) which determines the set of active lines, and the intensity of the stimula- tion with a “temporal byte’ of frequency code. The brain’s basic “byte,” therefore, has two dimensions, a spatial dimension and a temporal dimension. Two independent sets of information may be encoded in these two dimensions, and they may then interact in the receiving structure in a way determined by that structure, Notice that the spatial aspect of the byte is essentially digital information, and that the temporal aspect of the byte is essentially analog information, although it is encoded in the frequency of digital pulses. The mathematical treatment of this is an information theorist’s nightmare, although it can be done, but from a practical standpoint there are some clear advantages. Digital information output from a structure which determines the type of action to be taken and analog information output from another structure which determines intensity of action required may ‘‘gate”’ one another ina third location to produce an output stream which simultaneously defines the nature and magnitude of the action taken. One could think of it as specifying the enabling of a set of switches with an appropriately coded digital byte while presenting a set of analog values to the switched lines. We do see this sort of thing of course in some electronic 10 applications, but the brain makes use of this, and much more complicated inter- actions, in its internal processing. It may use the information from one aspect of the byte to determine the nature or extent of the operation to be performed on the informa- tion in the other aspect of the byte. Two additional properties of the neuron need to be mentioned to complete our understanding of the basic gate. The first is a different type of inhibitory input. The “negative synapse” described earlier puts an inhibitory input into the cell body to act on the analog sum there and retard the achieve- ment of firing threshold at the axon hillock. This action of course simply antagonizes (with a specified weight) the action of all the positive inputs. Clearly, it does this without regard to which input it is antagonizing. It is also possible to have a “negative synapse” which antagonizes only a specific synaptic input. This is called ‘presynaptic inhibi- tion,” because it may be thought of as a disable input to one of the input one shots. The final desirable property of the neuron as a computer element is that speed of transmission of pulses down the axon may vary over a wide range (although it is always the same in any given axon). This means that we may use high speed axons to move data quickly, but low speed axons may be employed as delay lines. Since axons can have branches coming off at any point, we may have tapped delay lines. We shall see some stunning examples of the utility of this feature. It should be apparent by now that the basic neuron is an enormously powerful tool. In practice, few situations call for all of the complexity of this device, and it is frequently seen acting as simply a switch or AND gate or other very domestic sort of creature. Indeed, in many situations, neurons take on a variety of specialized shapes and connections which optimize them for one or another function, to the exclusion of others. In all cases however, their operation may be understood in terms of the basic design we have discussed. Now that we have some terms for the basic elements, let us take a leap to the other end of the size spectrum and examine the overall structure of the brain. The exact anatomy is actually of little relevance for our purposes, but it may help to have a visual image of the device as we discuss the features of its parts. Figure 3 shows the general appearance of the human brain, together with some of its internal structure. Figure 4 shows the general organization of the parts as they would appear if the brain were taken out of the body, unfolded, and flattened out in a neat plan view. The functional structures of the brain may be generally divided into two cate- gories, fiber tracts and nuclei (plural of nucleus). Fiber tracts are simply bundles of axons going from somewhere to somewhere else, the cabling and wiring of the brain, The nuclei are groups of cell bodies. Each Art-by-Computer,, - an unusual gift idea File 1 SW SIS Sie all File! File3 File 13 File 19 File 20 File 26 XS | |) 7) KI wel] S File 27 File 41 File 45 File 46 File 6 File 61 Reproductions of graphic designs generated on a Tektronix 4051 Graphics Computer/4662 Digital Plotter these black-on-white prints are 9 3/4H by 12 3/4W and are suitable for framing or mounting. Price: $2.00 ea./$20.00 for the set of 12, postage paid. Specify File #s or Set #1. Send check or money order to: Leland C. Sheppard, Dept B, PO Box 68851, Sunnyvale, California 94086. California residents add 6% sales tax. Allow 2 weeks for personal checks to clear. © Leland C. Sheppard, 1977. Circle 57 on inquiry card. QYTE January 1978-21 INTERNAL —| CAVITY, BASAL GANGLIA (STRIATUM) cEREBELLUM—~ Figure 4: A “plan view” of the brain showing the re- fationship of the major parts as it would appear if it could be unfolded. 22 GY IE January 1978 CORTEX LIMBIC SrSTEM ~— DIENCEPHALON ~~ MESENCEPHALON Spans me ULL “S— spinat coro nucleus may be thought of as analogous to a central processor with a dedicated function, and {in most cases} a hardwired or ROM program. Most of the nuclei are irregular blobs of cell bodies, but in some cases the cell bodies are atranged in layers and the layers form a folded sheet of cells. In this case it is called a cortex rather than a nucleus, but the idea is the same. (The most famous of course is the cerebral cortex, of which humans are very proud because it is better developed in man than in most species.) The cells in the nuclei may be divided into two types: loca! neurons, whose function is in the data processing internal to the nucleus, and whose axons do not leave the nucieus, and output neurons which give rise to the axons that make up the fiber tracts and communicate with other nuclei. There are thousands of nuclei, of all levels of size and sophistication. Unfortunately, there is very little system to their names, and the names are either in Latin, or unpronounca- ble (Nucleus of Darkeschwitz, etc). The fiber tracts are bad too (Habenulointerpeduncular tract). The only rational thing to do with the names of neuroanatomy is to endure them or ignore them. We shall try to ignore them. It will help however if you will take the time to learn the names of a few of the major divisions of the brain which are shown in figure 4 and to remember their basic relation to one another. The most important items, from bottom to top, are: the spinal cord, the medulla, the pons, the cerebellum, the mesencephalon, the diencephalon (and its two major subdivisions, the thalamus and the hypothalamus), the limbic system, the striatum, and the cerebral cortex, This bottom to top sequence corresponds in a general way to a sequence of increasing- ly more global levels of control, from most detailed and specific, to most general and abstract. It also corresponds roughly to the evolutionary sequence from oldest and most primitive to most recent and advanced. All of the apparatus shown here is present by the time the evolutionary level of the mammals is reached. The basic architecture of the system is hierarchical. Each of the major functions of the system is partially organized at each level of the system, rather than particular struc- tures being devoted to particular major functions. At the lowest levels, there are a multitude of relatively simple processing elements doing similar jobs, and at the higher levels there are a few very complex and powerful processing elements defining system goals and priorities, and organizing the activities of the lower levels to achieve them. On the input side, the lowest levels gather raw data which is then progressively ab- stracted, sorted and refined at each stage according to general guidelines which may be hardwired or provided by higher levels, The highest levels then receive abstract symbolic information about the general state of the environment rather than details. (“There is a black cat there” as opposed to “The following points of the visual field are dark.”) Similarly, output functions begin at the highest levels, which determine general goals and strategies and transmit these in the form of statements about more limited momentary objectives to lower levels, which in turn send Information about desired actions and timing to the lowest levels for execution. Thus, at each level there are a number of relatively independent processing elements pursuing their own jobs in parallel real time, while trading information with echelons above and below, and laterally with one another. It follows that it doesn’t make sense to ask where in the brain any large scale function is processed. Different aspects of it will be handled in different portions of functional subsystems which are represented at all major levels of the physical system. It might sound hopeless to try to follow the operation of such a device, but in practice there is order, not chaos. At the lower levels where semi-independent processors are most numerous, there is least diversity among them. The organization is in many ways like a military command chain, and one doesn’t Continued on page 96 \ UP AND RUNNING TDL EQUIPMENT USED BY NEW JERSEY PUBLIC TELEVISION TO PROCESS NEW JERSEY GUBERNATORIAL PRIMARY ELECTION RETURNS John Montagna, computer engineer (above left), lead this successful network team in generating election results speedily, efficiently and reliably using predominantly TDL hardware and soft- ware. Montagna created three programs to get the job done. The text for a SWAPPER pro- gram was written and assembled using the TDL TEXT EDITOR and Z80 RELOCATING MACRO ASSEMBLER. The SWAPPER text and all debugging was run through TDL’s ZAPPLE MONITOR. The relocatable object code was punched onto paper tape. A MAIN USERS program updated votes and controlled air dis- play. An ALTERNATE USERS program got hard copy out and votes in. The latter two programs were written in BASIC. Montagna modified the ZAPPLE BASIC to permit time- sharing between the two USERS programs. TDL’s XITAN SYSTEMS have the capacity to do similar tasks for you. Write to us for XITAN information and the name of your nearest TDL dealer. Circle 107 on inquiry card. Four screens were incorporated, two terminals entered votes as they came in and were used to call back votes to check accuracy. Mon- tagna called on the power and flexibility offered by TDL’s ZPU board and three Z-16 Memory boards. Montagna’s setup worked constantly for over four hours updating and displaying state-wide and county-wide results without flaw. “t chose TDL because they have all the soft- ware to support their hardware, and it’s good; it has the flexibility to do the job.” John Montagna We salute John Montagna and NEW JERSEY PUBLIC BROADCASTING for spearheading the micro-computer revolution. { TECHNICAL 1] DESIGN 2/1 ABs RESEARCH PARK BLDG.H 1101 STATE ROAD PRINCETON, NEW JERSEY 08540 (609) 921-0321 BYTE |zouary 1978 23 In this magazine, alone, there are probably a dozen ads for small computers. New companies are breaking ground like spring flowers. How, then, do you determine which computer offers the features you need most...at the price you can afford? We'd like to propose seven basic questions to help you make an intelligent decision. How complete is the computer system? Many buyers of small computers are in for a rude awakening when they have to spend additional money for interfaces. The Sol-20 Terminal Computer was the first complete small computer system. Everything you need to make it work is included in the basic package. Is powerful system software available? It won't do if your system is “tongue-tied? Processor Technology Corporation has devoted more effort to the development of software than any other small computer maker. Our latest offering is the first fully implemented disk operating system for a small computer: PTDOS. It contains over 40 major commands, several languages and numerous utilities. Our high level languages include Extended BASIC, Assembler, FORTRAN? FOCAL and PILOT* Is the system easy to expand? More and more computer owners are expanding their small computers to handle business and other specialized requirements. The largest Sol system can handle 64K bytes of RAM memory and operate with a three megabyte on-line disk memory. Sol systems use the S-100 Bus. So you can use a wide variety of hardware. *Avuiluble soon. 24 BYTE January 1978 Seven points to consider nero z you buy your An \ Ymall computed re is the computer well-engineered? Our Sol systems are the most conservatively rated and ruggedly built in the industry, period. In addition we designed them with you, the user, in mind; Sols are easy to build and a joy to operate. Does it have proven reliability? What is the track record? There are over 5,000 Sol systems in the field. Our track record for reliable performance is unparalleled in the small computer field. Does it have good factory support? A computer is a complex piece of hardware. So you want to be sure it is backed up with complete manuals, drawings and a factory support team that cares. Processor Technology offers the most extensive documentation of any small computer manufacturer. And we maintain a patient, competent telephone staff to answer your questions. Are maintenance and service people accessible? ®@ Where are they located? Processor Technology has maintenance and service people in over 50 cities around the U.S. As you continue turning the pages, see how we stack up to the other computers in this magazine. If we've succeeded in whetting your appetite, see your Sol dealer or write for information on the complete family of Sol computers. Processor Technology Corporation, Box B, 7100 Johnson Industrial Drive, Pleasanton, CA 94566. (415) 829-2600. Circle 89 on inquiry card. Subsystem Each board is a standout. Together, they're a powerhouse. In the beginning there were boards, thousands of them. That's how we started in the business. Making memories and interfaces for other people's computers...and making them better. Now that our own Sol has become the number one small computer, you might think we're putting less emphasis on our board business. Not so. We're just doing more creative things with them. One neat package gets your computer on the air. For example, we've built Subsystem B, which ties together five Processor Technology modules into acompletely integrated system that makes other S-100 Bus computers work almost as well as our Sol. Subsystem B includes a memory module. three input/output modules, a general purpose memory, and appropriate software. A specialized software program called CUTER knits together your computer and its peripherals to create an integrated, smoothly working system. It's the fastest, cleanest way to geton line, and it costs less than if you bought each module separately. You get your choice of two low power, reliable memory modules in 8K or 16K capacity. Our VDM-1 video display module (still $199 in kit) is the industry standard display device with over 6,000 in use. Our CUTS high speed. low cost (S110 in kit) audio cassette interface is the most reliable on the market and is supported by our broad line of cassette software including Extended BASIC, FORTRAN* PILOTS FOCAL and numerous others. And our 3P +S input/output module offers a low cost way to handle virtually all the 1/O needs of any S-100 Bus compatible computer system. There are close to 10,000 in the field. Price is just $149 in kit. Yes, we may have become the maker of the Number | small computer — the Sol. But we haven't neglected the quality of our board business. We can't afford to... because we use many of them in our own computers. For our most recent literature and price list see your dealer or write Processor Technology Corporation, Box B, 7100 Johnson Industrial Drive, Pleasanton, CA 94566, (415) 829-2600. Processor Technology “Available soon. See it at your Sol dealer... ARIZONA Byte Shop Tempe 813 N. Scottsdale Rd. Tempe, AZ 85281 (602) 894-1129 Byte Shop Phoenix 12654 N. 28th Dr. Phoenix, AZ 85029 (602) 942-7300 Byte Shop Tucson 2612 E. Broadway Tucson, AZ 8571! (602) 327-4579 CALIFORNIA The Byte Shop 1814 Universi ly Aye. Berkeley, CA (415) SYees68 The Byte Shop 6041 Greenback Lane Citrus Heights, CA 95610 (916) 961-2983 Computer Center 1913 Harbor Blvd. Costa Mesa, CA 92627 (714) 646-0221 The Byte sop Hayerard, CA 84541 (415) 537-2983 The Byte Shop 16508 Hawthorne Blvd. Lawndale, CA 90260 (213) 371-2421 The Computer Mart 633-8 West Katella Orange, CA 92667 (714) 633-1222 Byte Shop 496 South Lake Ave. Pasadena, CA 91101 (213) 684-3311 Micro-Computer Application Systems 2322 Capitol Avenue Sacramento, CA 95816 (916) 443-4944 Byte Shop 321 Pacific Ave. San Francisco, CA 94111 (415) 421-8686 The Byte Shop 2626 Union Avenue San Jose, CA 95124 (408) 377-4685 The Byte Shop 509 Francisco Blvd, San Rafael, CA 94801 (415) 457-9311 Byte Shop of Tarzana 18423 Ventura Bivd. Tarzana, CA 91356 (213) 343-3919 The Byte Shop 2989 North Main St. Walnut Creek, CA 94596 (415) 933-6252, 26 BYTE January 1978 COLORADO Byte Shop 3101 Wainut St. Boulder, CO 80301 (303) 449-6233 FLORIDA Byte Shop of Fort Lauderdale 1044 East Oakland Park Blvd. Ft, Lauderdale, FL 33334 (05) 561-2983 Byte Shop of Miami 7825 Bird Road Miami, FL 33155 (305) 264-2983 Microcomputer Systems Inc. 144 So. Dale Mabry Hwy. Tampa, FL 33609 (813) 879-4301 GEORGIA Atlanta Computer Mart 5091-B Buford Hwy. Atlanta, GA 30340 (404) 455-0647 ILLINOIS, Champaign Computer Company Stan, Nell Street Champaign, ih 61820 (217) 359-58: The wanbare — 623% South Wright St. Champaign, IL 61820 (217) 352! 5435 itty bitly machine co. 1322 Chicago Ave. Evanston, IL 60201 (312) 326-6800 itty bitty machine co, 42 West Roosevelt Lombard, IL 60148 (312) 620-5808 INDIANA The Data Domain 406 So. College Ave. Bloomington, IN 47401 (812) 334-3607 The Data Domain 7027 N. Michigan Rd. Indianapolis, IN 46268 (317) 251-3139 IOWA The Computer Stora of Davenport 4128 Brady Street Davenport, [A 62806 (319) 386-3330 KENTUCKY The Data Domain 3028 Hunsinger Lane Louisville, KY 40220 (502) 456-5242 MICHIGAN The Computer Store ‘of Ann Arbor 310 East Washington Ann Arbor, MI 48104 (313) 995-7616 General Computer Store 2011 Livernois Troy, Mi 48084 (313) 362-0022 MINNESOTA ae pepe, Inc. 3515 W. 71 Minnea| cits an 55435 (612) 927-5601 NEW JERSEY Hoboken Computer Works. No. 20 Hudson Place Hoboken, NJ 07030 (201) 420-1644 The Computer Mart ‘of New Jersey 501 Route 27 Iselin, NJ 08830 (201) 283-0600 NEW YORK The Computer Mart of New York 118 Madison Ave. New York, NY 10001 (212) 686-7923 The Computer Corner 200 Hamilton Ave, White Plains, NY 10601 (974) 949-3282 NORTH CAROLINA ROMs ‘N’ RAMs: Crabtree Valley Mall Raleigh, NC 27604 (919) 781-0003 OHIO Byte Shop 2492 Chester Lane Columbus, OH 43321 (614) 486-7761 Computer Mart of Dayton 2665 S. Dixie Ave. Dayton, OH 45409 (513) 296-1248 OREGON Byte Shop Computer Store 3482 SW Cedar Hills Blvd. Beaverton, OR 97005 (503) 644-2686 The Real Oregon Computer Co. 205 West 10th Ave. Eugene, OR 97401 (603) 484-1040 Byte Shop Computer Store 2033 SW 4th Ave. Portland, OR 97201 (503) 223-3496 RHODE ISLAND Computer Power, Inc. M24 Airport 1800 Post Rd. Warwick, Ri 02886 (401) 738-4477 SOUTH CAROLINA Byte Shop 2018 Green St. Columbia, SC 29205 (803) 771-7824 TENNESSEE Microproducts & Systems 2307 E. Center Street Kingsport, TN 37664 (615) 245-8081 TEXAS Computer Port |. Collins Arlington, TX 76011 (817) 469-1502 Computertex 2300 Richmond Ave. Houston, TX 77006 (713) 526-3456 Interactive Computers 7646% Dashwood Rd. Houston, TX 77036 (713) 772-5287 Neighborhood Computer Store #20 Terrace Shopping Center 4902 - 34th Street Lubbock, TX 79410 (806) 797-1468 The Micro Store 634 So. Central Expressway Richardson, TX 75080 (214) 231-1096 Processor i VIRGINIA The Computer Systems Store 1984 Chain Bridge Rd. McLean, VA 22101 (703) 821-8333 The Home Computer Center 2927 Virginia Beach Blvd. Virginia Beach, VA 23452 (804) 340-1977 WASHINGTON Byte Shop Comptes Store 14701 N.E. 20th Bellevue, WA B00 (206) 746-0651 The Retail Computer Store A410 N.E. 72nd Seattle, WA 98115. (206) 524-4101 WISCONSIN ‘The Madison Computer Store 1863 Monroe Street Madison, WI $3711 (608) 255-5552 The Milwaukee Computer Store 6916 W. North Ave. Milwaukee, WI 53213 (414) 259-9140 WASHINGTON D.C. Georgetown Computer Store M Street NW Washington, D.C. 20004 (203) 362-2127 CANADA Trintronics 160 Elgin St. Place Ball Canada Bisranentee atarto KaP 204 Computer Hie Ltd. 1543 Bayview Ave. Toronto, Ontario M1K 4K4 (416) 484-9708 First Canadian Computer Store Ltd. 44 Eglinton Ave. West Toronto, Ontario M4R 1A1 (416) 482-8080 The Computer Place 186 Queen St. West Toronto, Ontario MSV 1Z1 (416) 598-0262 Basic Computer Group Lid. 1548 East 81 Vancouver 8.0, V6 4R8 (604) 736-7474 Pacitic Computer Store 4509 Rupert St. Vancouver, B.C. VSR 2/4 (604) 438-3282 Circle 89 on inquiry card. ay The IRS and the Elizabeth M Hughes 5831 Hillside Dr Doraville GA 30340 Few computer hobbyists ever have enough money to put into expanding, up- grading or otherwise improving their sys- tems, New products for the home computer are appearing almost daily and new needs ("If | only had another 4 K of mem- ory. . .") become visible as the computer re- ceives increased use. It’s hardly surprising, then, that many small-systems owners are thinking of ways to make their com- puters pay for themselves. Many succeed in penetrating the chinks in the armor of the local business community (or whatever) and begin to earn some money from the enterprise. The ecstasy of turning a dollar from a hobby activity is hard to beat, but after that first burst of excitement, it's necessary to remember the cloud on the horizon: the Internal Revenue Service (IRS), which is interested in a/f earnings. The purpose of this article is to acquaint you with the additional tax schedules you must prepare and records you must maintain if you start earning money with your computer. On the brighter side, it will also give you an idea of the deductions you can take on the strength of your new status as a small business. Tax law is complex, however, and an article of this length can only offer a thorough overview of the situation. Anyone starting a small business would be well- advised to augment the information pre- sented here by getting the free [RS publica- tions on the subject which are listed at the end of this article. Are You a Small Business? In deciding whether or not you are a “small business” for federal income tax purposes, the main considerations are (a) did you earn any money from the enter- Computer Entrepreneur prise in question during the past year?; and {b) do you want to take deductions based on your status as a small business? If you take business-based deductions, your business can be a comfortable tax loss, but only for a short time. If you do not pro- duce a taxable profit during at least two of every five consecutive years, you do not qualify as a business, in which case you may find yourself in the uncomfortable position of having claimed deductions in previous years from a nonexistent business. There- fore, unless you seriously intend to expand your money earning computer activities to the point of making a net profit, it’s wise to simply report computer income under miscellaneous income on your regular tax form and leave it at that. Other considerations arise on a state or local level. Before you decide to become a small business, be sure to find out what's involved in your area. Zoning ordinances in some cities render even in-the-home businesses illegal in certain areas. Some cities and states require an annual licensing fee from a// small businesses, and state law varies radically regarding which goods or services are subject to sales tax. Inquiring into these matters at the outset will prevent problems later. In most areas, small businesses are not required to incorporate or to register their trademarks, if any (although they are per- mitted to do so); but all states and some municipalities have laws regarding small businesses which must be taken into con- sideration. Telephone calls to state and local government offices will usually answer these questions efficiently. Satisfying the IRS New smali businesses, especially if they are responsible for tax losses in their first The ecstasy of turning a dollar from a hobby activity is hard to beat, but after that first burst of excitement, it's neces- sary to remember a cloud on the horizon: the IRS, BYTE Jamary 1978 27 New small businesses, especially if they are responsible for tax losses in their first year or wo, are prime targets for IRS. audits. One successtul business 1 know keeps records in paper bags, ane marked “expense” and the other 28 “income.”” BYTE January 1978, year or two, are prime targets for IRS audits. The thought of being audited by the IRS strikes terror into even the most innocent hearts, but if you keep complete and accurate records you can face even that contingency with unruffled calm. The general rule is keep everything. In detail, this translates into keeping all receipts for business expense, paying as many business expenses by check as possible to provide the additional documentation of a cancelled check, and keeping thorough records of all income from your business. Remember that the IRS is always looking for falsified records of all sorts and has no reason to suppose that you haven’t been doing the same, so don’t rely on your com- puter printout or handwritten records to satisfy them. All those odd sized receipts may be a pain to keep, but if you're audited, they'll save the day. Records needed fall into three categories: income, outlay and miscellaneous. Income records serve as the basis for calculating your total business income at tax time. For example, if you bill someone for a computer service, keep a copy of the invoice you send out and note on it such particulars as date, service, customer’s name and address, and postage required to send the bill. When pay- ment is received, mark the invoice with the date of payment and file a photocopy of the check with it. A record of the date of pay- ment is especially desirable if you are paid in cash, and for this reason an inexpen- sive receipt book can be a worthwhile investment. Records of outlay serve to document expenditures made for the business. They are especially important because they support any business deductions you claim at the end of the year. Anything purchased exclusively for business use is a safe deduc- tion. Thus, if you buy a cassette which is used solely for business data (as opposed to programs for your private amusement), it counts as a business expense; but if you buy a sheet of stamps, you can only count as business expense those stamps used for business purposes, such as mailing bills or advertising, Miscellaneous records document your claim to be a business. They include copies of any advertising you do, business cor- respondence, and announcements (or news- clips) of activities you participated in which mention that you are the proprietor of your business. The central fact to remember is that the IRS takes nobody's word for anything and looks at any record with a critical eye. Fraud and conspiracy to defraud are ever present, and the IRS is continually on guard against them. Therefore, any record which involves a business other than your own (eg: the company you bought x from), a bank, or another individual (a customer, a news reporter, whatever) helps your cause by providing someone who can altest to your business activities, Afl of this inevitably sounds paranoid, but a little well-placed forethought and paranoia can save trouble later. Getting Organized Naturally, all these documents amount to a lot of paper, usually in odd sized scraps that have the knack of vanishing at incon- venient moments. There are — several approaches to making life easier al tax time. One successful “small business’ | know uses paper bags. The entrepreneur of this enter- prise keeps one marked expense and one marked income by the desk and pitches all documents into one or the other. When preparing tax forms, he sorts the bags, com- bining related documents into rubber- banded bundles, and, after the forms are mailed, puts all the documents pius a copy of the tax forms into one large paper bag. Stapled shut and labelled with the year, it then takes its place among previous years’ bags on a shelf as insurance against the day the IRS decides to audit. | personally prefer a somewhat more complicated system employing file folders. Each client or type of expense has its own file folder which | can use not only for tax purposes but as a basis for estimating antici- pated needs. If the money can be available before the expense arises, life is made easier; and if a service can be offered Lo a client just as he/she is about to request it, business flows more smoothly. Regardless of system, however, the principle is the same: keep hard copy proving the legitimacy of every deduction and every bit of claimed income. Try dif- ferent approaches until you find the one that suits you best, and then stick with it. It's your best defense against allegations of tax fraud, If all this sounds like a lot of trouble, you're right. But it has advantages. And in the language of income tax, ‘‘advantage” is spelled deduction. Small business expenses are deductible. What counts as a business expense? Schedule C, the main tax form businesses must fill out (more about this later), lists several categories. Let’s consider them one by one. typical accéss time. Assembled. Tested. Burned in. Guaranteed.’ - ~ > Like our 16k dynarhic RAM, Built as solid as the 4,400 year-old pyramids. - > ve « * didn’t stop . - ' a : Ancient Egyptians © Bank Select . ~ © Condgervative thermal design with just one pyramid. The Great, ©’ Write Protect with alarm for * Complete S-100 compati- “ Pyramid stands on the Plainof ~ - — each 4k block bility, including the Alpha of Gizeh with two other monuments © Full Schmitt trigger buffering MicroandZ-2. _ = i erected for kings and queens. + ¢ No DMA restrietions The Great 16k Dynamic - Dynabyte didn’t stop withone . ¢ Complete S-100 bus com- Memory. $399. 16k dynamic RAM, either. Now * , patibility, including the Alpha © Highly cost effective you can get 16k and 32k fully Micro and Z-2. * No wait states Static RAM’s that are built with the The Great 32K Static © Transparent refresh same unmatched Memory. 250 ns., $995. 450 * 16k addressing boundaries ability and manufa Skill ns., $925. * Widest S-100 mainframe and that went into Egypt’s wonders of © 4k boundary addressing disk system compatibility the ancient world. ¢ Full Schmitt trigger buffering All of Dynabyte’s memories Hines We SY Cum: il a © No DMA restrictions et vad industrial grade stand- completely built. Assembled, ards. ign, components, con- tested and bumed in. We don’t Dyn: v struction, testing and perfor- leave anything undone. That way, ia id Be antl s ites E mance. But if a module ever needs can buy any Dynabyte repair, we provide factory service Paacens ioe. that it is backed acest Bt: can be fun; wih 24 hour turnaround for both by a factory guarantee for one full z warranty and non-warranty work. 7 , But how about testing it? ‘ bass and semt kits 'can't Do you have the test programs waeh os se ilinerad apy Our 16k static and our 32k and equipment? Do you know Pyneby emt your localcompal static and our which memory test program | Store. You can also pick up com- static are available with either 250 uncovers pattern sensitivity? plete product information while ns, or 450 ns. access time. Our Or which finds shorted data yey ene: fe 250 ns. module is completely bits but won’t find address it if you haven’t got a local compatible with the 4MHz Z-80A decoder faults? computer store, write Dynabyte, . The 450 ns. modules We do. It’s our business. We Inc., 4020 Fabian, Palo Alto, CA are compatible with the 8080 and have the 200 MHz osclllo- | 94303. Or telephone (415) the faster 3MHz 8085 processors. peal in ut anlar 494-7817. The Great 16k Static urn-in chambers, an e tes! programs. We find the bugs, rr eta ns., $555.450 even the subtle ones. = ‘aie block akong dt - Which ees you concentrate DYNABYTE addressing on computing. boundaries Builders of Great Memories Circle 37 on inquiry card. BYTE January 1978 29 The cost of replacing a 2102 programmable memory which gave up the ghost is deductible as a repair cost, but upgrading it to a 2102-1 or adding another 4 K bytes of memory to the system is an improvement and must 30 be treated differently. BYTE January 1978 Depreciation If you buy any income producing property or property used in your business which has a limited useful life that can be reasonably estimated, you may, during the years of its useful life, recover some of its cost in the form of depreciation. If, for example, you buy an item to use in your business that will wear out of need replace- ment in time, you can deduct a certain percentage of its cost every year of its estimated life. If you are using the item for nonbusiness as well as business purposes, you may only deduct the depreciation for the period of business use. Thus, if you buy a computer which will be used one third of the time for business and the other two thirds of the time for nonbusiness uses, only one third of its annual depreciation can be deducted as a business expense. There are many ways of calculating depreciation, Tax law surrounding it is too complicated for thorough discussion in an article of this length, but since much of the expense of a small computer business arises from purchases of depreciable property, it is well worth a detailed study if you start your own computer-oriented business, Taxes on Business and Business Property This includes tax on business property (if you conduct your business on land you own and on which you must pay property tax); personal property tax, sales tax, gasoline tax, and the like if they were incurred in the ordinary course of business; state imposed corporate franchise tax; and, if you have employees, employment taxes. Of these, only sales tax (in applicable states) and gasoline tax are apt to be worth the computer entrepreneur's time as deductions, but be sure lo deduct all that apply and are documented. Other Business Property Deductions If you rent an office from which you conduct your business, the rent is deductible. If you operate from your home, however, you get no such deduction except under very special circumstances which are discussed in greater detail below. Unless you are engaged in your business full time, however, attempting to get this deduction will almost certainly be more trouble than it's worth. Routine repairs and maintenance of business property (the office, if any, the computer, etc) are deductible only if they do not increase the value, utility or life expectancy of the repaired item. Thus, the cost of replacing a 2102 programmable memory which gave up the ghost unexpec- tedly is deductible as a repair cost, but up- grading it to a 2102-1 or adding another 4 K of memory to the system is an improve- ment and must be treated differently. If you carry business insurance, the premiums are deductible. Salaries, Wages, and the Like If you have employees, there are deduc- tions for salaries, wages, commissions and numerous forms of employee benefits, but you may not deduct any salary, wage or cumpensation paid to yourself. [f you claim deductions in these categories, be prepared to prove that the service paid for (eg: date entry) actually was rendered, that the pay- ment for the service actually was made, and that the rate of pay was reasonable. You may also deduct the fees of lawyers, accountants and the like whose services your business uses. Financial Business Deductions You may claim deductions for bad debts arising from sales or services, for interest on loans made for or by the business, and for a number of other more complex financial matters which arise from certain business tax breaks. Unfortunately, computer enire- preneurs are not likely to qualify for the tax breaks, so | merely mention their existence in passing. Other Business Expenses Most of your deductions are apt to fit into this category. If you're renting an office, you can deduct the costs of heat, light, telephone and trash removal. These are also deductible if you qualify for a deduction for conducting business in your home, but in any event you can safely deduct business long distance telephone cails. The cost of postage is deductible for all business correspondence including mailed advertisements and bills, as is any paper and printing expense which you incur for your business. Similarly, your investment in receipt books, file folders and other supplies used to maintain tax records is deductible. One of the largest deductions of the com- puter entrepreneur will probably be for reference and research materials, If you purchase books or magazines which give you information which contributes to the success of your business (eg: an issue of a magazine containing a program for a service you subsequently sell), the cost of the pub- lication is a deductible expense. Member- ships in professional societies, subscriptions Price/Performance no one else has put together. IMSAI Introduces the PCS-80/30 Integrated Video Computer (13 mHz microcomputer (3K ROM monitor [2K RAM (8 expansion slots (J 14mHz peated intelligent CRT (24 x 80) (7 Intelligent Keyboard (Parallel interface (12 serial interfaces (Graphic and edit CRT functions {28 amp power supply (All for $1499* assembled and tested. Software: ASSEMBLER, DOS, TTY and ACR BASIC, Commercial /Scientific BASIC, FORTRAN IV and more. Memory Options: 4, 16, 32 and 64K RAM memory bo