Extra A/MBM Edition m x H DO > m g H o Inside tfo IBM PCs o m m 5 o 0) 3 CD 3 CD- CD Turbo GameWbris™ Also recentjy released, Turbo GameWorks is what you think it is: "Games" and "Works." Games you can play right away (like Chess, Bridge and Go-Moku), plus the m Works— which is how computer ™ games work. All the secrets and strategies of game theory are there for you to learn. You can play the games "as is" or modify them any which way you want. Source code is included to let you do that, and whether you want to write your own games or simply play the off-the-shelf games, Turbo GameWorks will give hours of diversion, education, and intrigue. George Koltanowski, Dean of American Chess, and former President, United States Chess Federation, reacted to Turbo GameWorks like this, "With Turbo GameWorks, you 're on your way to becoming a master chessplayer'1 and Kit Woolsey, writer, author, and twice Champion of the Blue Ribbon Pairs, wrote, "Now play the world's most popular card game— Bridge . . . even program your own bidding or scoring conventions" Suggested retail: $69.95, Turbo Graphix Toolbox" It Includes a libraiy of graphics routines for Turbo Pascal programs. Lets even beginning programmers create hJgh-resolution graphics with an IBM, Hercules,™ or compatible graphics adapter. Our Turbo Graphix Toolbox Includes all the tools you'll ever need for complex business graphics, easy windowing, and storing screen images to memory. It comes complete with source code, ready to compile. Suggested retail: $69.95. Recognition lor Borland International has come Irom business, trade, and media, and includes both product awards and awards lor technical excellence and marketing. Borland was named "Company ol the Year" by PC Magazine; Sidekick, the ft / best seller lor the IBM PC, was named "Product ol the Year" by InloWorld; Turbo Pascal was selected one ol PC Week's Top 10 Products lor 1984; SuperKey won one ol PC Magazine's "Best ol 1985" awards; Rellex, The Analyst was recognized in the "Software Products ol the Year" awards by Into World; and Rellex and SideKick were both nominated lor British Micro Awards in 1986 . Turbo Database Toolbox* A perfect complement to Turbo Pascal, because it contains a complete library of Pascal procedures that allows you to search and sort data and build powerful database applications. Having Turbo Database Toolbox means you don't have to reinvent the wheel each time you write a Turbo Pascal program. It comes with source code for a free sample database— right on disk. The database can be searched by keywords or numbers. Update, add, or delete records as needed. Just compile It and It's ready to go to work for you. Suggested retail: $69.95. Technical Specifications: TURBO PASCAL 3.0 Minimum memory:128K; includes 8087 and BCD features for 16-bit MS-DOS and CP/M-86 systems. CP/M-80 version minimum memory: 48K; 8087 and BCD features not available TURBO DATABASE TOOLBOX Minimum memory: 128K. CP/M-80 minimum memory: 48K. Requires Turbo Pascal 2.0 or later. TURBO GRAPHIX TOOLBOX* Minimum memory: 192K. Requires PC/MS-DOS 2.0 or later. Turbo Pascal 3.0, and IBM C6A, Hercules Monoctrome Card or equivalent. TURBO TUTOR 2.0 Minimum memory: 192K. CP/M-80 version minimum memory 48K. Requires PC/MS-00S 2.0 or later and Turbo Pascal 3.0. TURBO EOITOR TOOLBOX* Minimum memory: 192K. Requires PC/MS-DOS 2.0 or later and Turbo Pascal 3.0. TURBO GAMEWORKS* Minimum memory: 192K. Requires PC/MS-DOS 2.0 or later and Turbo Pascal 3.0. TURBO PROLOG* Minimum memory: 384K. REFLEX: THE ANALYST* Minimum memory: 384K. Requires IBM CGA, Hercules Monochrome Card or equivalent. Works wilh Intel's AboveBoard-PC and -AT; AST's RAMpage! and RAMpage! AT; Quadram's Liberty-PC and -AT; Tecmar's640 Plus; IBM's EGA and 3270/PC; AT&T's 6300 and many others. REFLEX WORKSHOP* Minimum memory: 384K. Requires Rellex: The Analyst. Two disk drives or hard disk recommended. TURBO LIGHTNING* Minimum memory: 256K. Two disk drives required. Hard disk recommended, LIGHTNING WORO WIZARO* Minimum memory: 256K. Requires Turbo Lighlning. Turbo Pascal 3.0 required to edit source code. SIDEKICK* Minimum memory: 128K. TRAVELING SIDEKICK* Minimum memory: 256K. SUPERKEY* Minimum memory. 128K. 'For IBM PC, AT, XT, PCjr and true compatibles only, running PC/MS-DOS 2.0 or later. inm Pascal Turbo Pascal® 3.0 '%r the IBM PC, the benchmark Pascal compiler is undoubtedly Borland International's l\irbo Pascal'' says Gary Ray of PC Week. We and more than 500,000 other people around the world think Mr. Ray got that right. Since launch, Turbo Pascal has become the de facto worldwide standard in high-speed Pascal compilers. Described by Jeff Duntemann of PC Magazine as the 11 Language deal of the century" Turbo Pascal is now an even better deal than that— because weVe included the most popular options (BCD reals and 8087 support). What used to cost $124.95 is now only $99.95! You now get a lot more for a lot less: the compiler, a complete— ]y integrated programming environment, and BCD reals and 8087 support— all for a suggested retail of only $99.95. DP* uoriana s business productivity programs: Reflex: The Analyst' Analytical database manager. Provides complete new look at data normally hidden by programs like 1-2-3" and dBASE * Best report generator for 1-2-3. |\ Reflex Workshop' Important new addition to Reflex: The Analyst. Gives you 22 different templates to run your business right. SideKick' Complete RAM-resident desktop management includes notepad, dialer, calculator and more. Traveling SideKick' Electronic version of business/personal diaries, daytime organizers; works with your SideKick tiles; important professional tool. SuperKey" Keyboard enhancer. Simple macros turn 1000 keystrokes into 1. Also encrypts your tiles to keep confidential tiles confidential. Borland's Electronic Reference Programs: Turbo Lightning' Works with all your programs and checks your spelling while you type] Includes 80,000-word Random House* Concise Dictionary and 50,000- word Random House Thesaurus. Forerunner of Turbo Lightning Library. Lightning Word Wizard^ Includes ingenious crossword solver and six other word challenges. If you're into programming, Lightning Word Wizard is also a development toolbox and the technical reference manual for Turbo Liahtnina ^ Turbo Tutor® 2.0 Just released (July '86), the new Turbo Tutor can take you from "What's a computer?" on through to complex data structures, assembly languages, trees, tips on writing long programs in Turbo Pascal, and a high level of expertise. Source code for everything is included. New split screens allow you to put source text, in the bottom half of the screen and run the examples in the top half. There are quizzes that ask you, show you, tell you, teach you. You get a 450-page manual— which is not as daunting as it sounds, because unlike many software manuals, it was not written by oran- gutans. (With our all "almostrfree" upgrade, you can upgrade to Turbo Tutor 2.0 by sending us your master diskettes, proof of purchase, and $10.00, which covers shipping and handling.) Suggested retail: $39.95. Turbo Editor Toolbox* Recently released, we called our new Turbo Editor Toolbox a "construction set to write your own word processor." Peter Feldmann of PC Magazine covered it pretty well with, "A 'write your own word processor7 program for intermediate level programmers, with lots of help in the form of prewritten procedures covering everything from word wrap to pull-down windows" Source code is included, and we also include MicroStar, a full- blown text editor with pull-down menus and windowing. It interfaces directly with Turbo Lightning to let you spell-check your MicroStar files. JerrT Pournelle of BYTE magazine said, "The new Turbo Editor Toolbox is the Turbo Pascal source code to Just about anything you ever wanted a PCoompatlble text editor to do" Suggested retail: $69.95. ^ BOPl-AN News from Borland International! Vol 1 No. 1 w. •e frequently surprise people with inventive, imaginative software, and people frequently surprise us with the way theyuse it. For example, you'll read on this page how Michael J. WatJons of the Petroleum Technology Center in Houston, Texas, used Turbo Pascal® (and Turbo Graphix Toolbox" and Turbo Tutor®) to cut down the tedium and time in creating Circular Performance Profile Charts (CPPCs). We didn't know they existed, but you learn something new every day! Applications like CPPCs might not fit your exact needs, but at the same time they might stimulate fresh ideas in your mind about how you can put Turbo Pascal and the Turbo Pascal family to work for you. And thank you for your interest in and support for Borland International. pl^L— Philippe Kahn, President, Borland International INSIDE STORIES! ■ Turbo Pascal 3.0, already described by PC Magazine as 'language deal of the century'' is now an even betler deal than that, because we've included the most popular options (BCD reals and 8087 support). What used to cost $124.95 is now only $99.95! ■ Completely new Turbo Tutor 2.0 now available. New software. New manual. New split screens. New quizzes. Only $39.95. Upgrades available under Borland's "Almost-Free" upgrade plan. Details inside. LATE NEWS! ■ June/July Special Artificial Intelligence Issue of The Micro Technical Journal says, "Turbo Prolog looks like it's going to be a winner, for both the beginner and professional programmer." Turbo Pascal deliberately programmed to go around in circles Circular charts (or CPPCs) are used by Michael J. Watkins of the Petroleum Technology Center in Houston, Texas, to plot a single performance property for a large number of elastomers, which have elastic, rubber-like properties. Mr. Watkins wrote ub saying, "Because CPPCs condense a lot of data in one graphic, they can be very tedious and time-consuming to draw" What he did to solve those problems was to write a Turbo Pascal program for IBM® personal computers to "generate these charts quickly and easily" He used Turbo Pascal "because it has a companion set of very powerful graphics programs (Turbo Graphix Toolbox) which greatly simplifies the required programming. Turbo Pascal is not a difficult language to use and can be easily learned by persons who can program in FORTRAN or BASIC. An excellent tutorial (Turbo Tutor) is available for the novice or experienced programmer. The Turbo Pascal products are also very moderately priced" *-*• ^.JT. Ii'-./ V, \ ! /"■■£££ / >y ■■■/ 1 »^*v. /'■-■rr'- A EOHLANfl r 1 * Step-by-step tutorial, demo programs with source code included! Borland's new Turbo Prolog is the powerful, completely natural introduction to Artificial Intelligence Prolog is probably one of the most powerftjl computer program ming languages ever conceived, which is why weVe made it our second language— and "turbo- charged" it to create Turbo Prolog.1 Our new Turbo Prolog, the natural language of Artificial Intelligence, brings supercomputer power to your IBM* PC and introduces you step-tjy- step to the fascinating new world of Artificial Intelligence. And does all this for an astounding 199.95. s^ Turbo Prolog is to ]^eW Prolog what Turbo Pascal9 is to Pascal! Our Turbo Fiscal astonished everyone who thought, of Rascal as "Just another language " We changed all that— and now Turbo Rascal Is the de facto worldwide standard, with hundreds of , thousands of enthusiasts and users in I' universities, research centers, schoolB, and with pro- fessional program- mers, students, and hobtylsts. You can expect at least the same Impact from T\irbo Prolog, because while Turbo Prolog Is the most revolutionary and natural programming language, it Is also a complete development environ- ment—Just like Turbo Pascal Minimum memory 384K ^Turbo Prolog offers generally the fastest and most approachable imple- mentation of Prolog. Danyi itulrfn, ■■ AIBrpert'' j^^ Even if you've never p^ programmed before, ^^ our free tutorial will get you started right away You'll get started right away because we have Included a complete step-bystep tutorial as part of the 200-page Turbo Prolog Reference Manual Our tutorial will take you by the hand and teach you everything you're Jlkety to need to lmow about 'Turbo Prolog and artificial intelligence. For example: once you've completed the tutorial, youll be able to design your own expert systems utilizing Turbo Prolog's powerful problem-solving Think of Turbo Prolog as a high-speed electronic detective. First you feed it information and teach it rulea Then Turbo Prolog "thinks" the problem through and comes up with all the reasonable answers— almost Instantly. If you think that this is amazingpycu Just need to remember that Turbo Prolog Is a 5th-generaUon language— and the kind of language that 21st century computers will use routinely. In fact, you can compare Turbo Prolog to Turbo Rascal the way you could compare Turbo Rascal to machine language. r^w You get the complete ¥m Turbo Prolog lJ J programming system ~ for only $99.95 You get a complete Turbo Prolog development system Including: ■ The llghtuJng-fast Turbo Prolog incremental compiler and the Interactive Turbo Prolog editor. ■ The 200-page reference manual which Includes the step- ty-step Turbo Prolog tutorial ■ The five GeoBase™ natural query language database Including commented source code on disk— realty to compile. GeoBase Is a complete database designed and developed around U.S. geography. It Includes cities, mountains, rivers, and highways, and comes complete with natural query language. Use GeoBase Immediately "as ls,n or modify it to fit your own interests. So don't delay— don't waste a second-get Turbo Prolog new. $99.96 Is an amazingly small price to pay to become an Immediate authority— an Instant expert on artificial intelligence! The 21st century is only one phone call away. , BORLAND INTERNATIONAL 4585 SCOnS VALLEY DRIVE scorrs valley, ca 95066 (408)438-8400 TELEX: 172373 TTTJIfll I want XJJU{ the best! For credit card orders or the dealer nearest you call (800) 255-8008 in CA call (800) 742-1 133 Oggte Prvdut Price — Tuto Prolog — fefer The Arofysl fete* MtflVty — Rdkx. %fer Mtar&fep _ TutO /tear 3.0 w/8087 & BCD _ Tuto Past* lor CPIUSO Tuto D&tass Tootoox — Tuto Gapta Tooixu Tuto Tutor 2.0 Tuto Editor Tooixu — Tuto Gamemats _ Tuto UoMmg — LJQMwna HIM Wizard — Tuto Ugtmhg, Liojtwng Wotd Wizard — Sifefic* _SArf»r. Totekrrg SideXkk — StpeKey Ouafc USA add $10 per copy ft art AM res. art safes tax $99.95 J_ 149.95m ;_ 69.95* *_ 199.95-$- 99.95 *_ 69.95 $- 69.95 $- 69.95 $- 39.95 $- 69.95 $- 69.95 $- 99.95 $- 69.95 $- 149.95 $- 64.95 $- 69.95m$- 125 00-$- 69.95 $- $- $- Prices h*ide shipping to af US dies. Csrddhf desate you computes system: kermis: —8-bi — 16-t* fuse: —PCOOS —CPfhMO —t&OOS _ CPftM6 JUy cunfMMers name and model is: The disk sin I use is: D 3W D 55*' D 6" Payment VISA MC Montyoder Check Credit card expiration date I, <*• I I I 1 I I I I I I MOT COPY PROJECTED BG1& "ftVQW HOMEY-BACK GUARANTEE SteppaigAdOfess: . G* Sate Zfr COOs and (**d&ofaWU NOT be accepted lyBortod. OUa* USA makepayrme by bankdrafi. payable m US doits draw) on a US hart. 1*1*31 rm Oiler unbl Septerrtxs 1, 1996. "YES, i wtom 60 days of pudase you fad tat f* product does not perform in accontmce mti our dam* cat our custom service depwtnoi andwewW gtadfy arrarjje * retard. Prices sir/ect to change mtvut notice. Turbo Prolog 1.0 Technical SpecUicattoat C mpiler ktjemsial compiler genuairq native in-line tode and linkable object modules. The linking lormat ixkHes a inker and is ccnjaB&e with the PC-DOS linker. Large memory model mT(..»t CompHes over 2500 lines per mhae on a &&ri mpc. intcsactive Mtrni &* %&&* *Ktofc$ tl powerful tteractrve test toVot. i toe compiler detects an error fte editor McnjatKa^posgK^tocOMUxapfifopriatelyfitxiaiit code, AHut-fm, TuboftolcQpmQjamafl caf ft pitor, and view the wring program's souve code. Type System: A tlexibte object-oriented type system is stfjportBd, Windowing Support- The sysm axjports toft gopht and tepeirOvliui F\* VO taffles, fxxtfrg-tornaltal HO. iicjjB. jnrf random access fas numeric ftttwit: Hegerx -32767 to 32767; fears. n-mtoii+m. Debugging: Conyiele built-in trace debuggng cap&Mes allowrtg single stepping olpogratrx. Inquiry 42 for End-Users. Inquiry 43 for DEALERS ONLY. H fi J m T£ff m ti HI 2 'jf i tttfMUCTWJT -^WWIP «i , / ^V V ^g _^ fcJ9^* pfflfe fc*^P*I^ t&O k > ^ HHB When computers get down to business , they move up to Maxell. Maxell was first to provide you with a 5W high density floppy disk, Just another example of how we keep you a step ahead, maxell THE GOLD STANDARD leriea, fiO Oxford Drive. Moonachie, Nl 0707- COVER ILLUSTRATED BY ROBERT TINNEY BYTE VOLUME II. NUMBER II. 1986 Inside the IBM PCs Editorial: The Struggle for Compatibility by G. Michael Vose 6 What's New 11 Book Reviews 23 The IBM RT Personal Computer by Richard O. Simpson 43 TVie IBM PC Convertible by G. Michael Vose 83 Intel's 80386 Architecture by Paul Wells 89 Virtual Memory, Virtual Machines by }on Shiell 110 A Protected-Mode Program for the PC AT by Ross P. Nelson 123 IBM PC Accelerators by Stephen S. Fried 140 Lotus/ Intel/ Microsoft Expanded Memory by Ray Duncan 168 Performance Programming by ]oel Rosenblum and Dan \acobs 181 RAM-Loadable Character Sets for the IBM PC by Richard Wilton 197 Speeding Up the PC AT by Brian K. Roemmele 209 Using Assembly Routines in MS-FORTRAN Programs by Mark Dahmke 217 Memory Manipulations by Alan R. Miller 232 Writing Assembly Language Interrupt Routines by William J. Claff 249 C Versus Assembly- C Plus Assembly by Tom Hogan 267 Best of BIX 288 BYTE's Ongoing Monitor Box 342 Listings From BIX page 320 From BYTEnet (617) 861-9764 on disk see insert card following page 176 in print see insert card following page 176 eBYTE IISSN 0360-5280) is published monthly with one extra issue per year by McGraw-Hill Inc. Founder lames H. McGraw (1860-19481. Executive, editorial, circulation, and advertising offices: One Phoenix Mill Lane. Peterborough. NH 03458. phone (6031 924-9281. Office hours: Mon-Thur 8:30 AM - 4:30 PM. Friday 8:30 AM - 1 :00 PM. 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Foreign subscriptions and sales should be remitted in US funds drawn on a U.S. bank. Please allow six to eight weeks for delivery of first issue Printed in the United States of America. Address all editorial correspondence to the Editor. BYTE. One Phoenix Mill lane. Peterborough NH 03458 Unac- ceptable manuscripts will be returned if accompanied by sufficient first-class postage. Not responsible for lost manuscripts or photos. Opinions expressed by the authors are not necessarily those of BYTE. Copyright © 1985 by McGraw-Hill Inc. All rights reserved. Trademark registered in the United States Patent and Trademark Office Where necessary, permission is granted by the copyright owner for libraries and others registered with the Copyright Clearance Center (CCC) to photocopy any article herein for the flat fee of SI 50 per copy of the article or any part thereof. Correspondence and payment should be sent directly to the CCC 29 Congress St.. Salem. MA 01970. Specify ISSN 0360-5280/83. SI. 50. Copying done for other than personal or internal reference use without the permission of McGraw-Hill Inc. is prohibted. Requests for special permission or bulk orders should be addressed to the publisher BYTE is available in microform from University Microfilms International. 300 North Zeeb Rd. Dept. PR. Ann Arbor. Ml 48106 or 18 Bedford Row, Dept. PR. London WCIR 4EI England Subscription questions or problems should be addressed to: BYTE Subscriber Service. P.O. Box 328. Hancock. NH 03449 BYTE 1986 Extra Edition • Inside the IBM PCs BYTE SENIOR VICE PRESIDENT/PUBLISHER Harry L. Brown EDITOR IN CHIEF Philip Lemmons BIX MANAGING EDITOR. BYTE Frederic S. Langa EXECUTIVE EDITOR. BIX George Bond ASSISTANT MANAGING EDITOR Glenn Hartwig CONSULTING EDITORS Steve Ciarcia Jerry Pournelle Ezra Shapiro Bruce Webster SENIOR TECHNICAL EDITORS Ion R. Edwards, Reviews G. Michael Vose, Themes Gregg Williams, Features TECHNICAL EDITORS Dennis Allen Richard Grehan Ken Sheldon George A. Stewart Iane Morrill Tazelaar Tom Ihompson Charles D. Wesion Eva White Stanley Wszola ASSOCIATE TECHNICAL EDITORS Curtis Franklin, Jr.. Best of BIX Margaret Cook Gurney. Book Reviews Brenda McLaughlin. Applications Software Reviews. San Francisco COPY EDITORS Bud Sadler. Chief Ieff Edmonds Faith Hanson Nancy Hayes Cathy Kingery Paula Noonan Warren Williamson Judy Winkler ASSISTANTS Peggy Dunham. Office Manager Martha Hicks L. Ryan McCombs June N. Sheldon NEWS AND TECHNOLOGY Gene Smarte. Bureau Chief. Costa Mesa Jonathan Erickson. Senior Technical Editor. San Francisco Rich M alloy, Senior Technical Editor. New York Cindy Kiddoo. Editorial Assistant. San Francisco ASSOCIATE NEWS EDITORS Dennis Barker, Microbytes Cathryn Baskin, What's New Anne Fischer Lent. What's New CONTRIBUTING EDITORS Jonathan Amsterdam, programming projects Mark Dahmke. video, operating systems Mark Haas, at large Rik Jadrnicek. CAD. graphics, spreadsheets Robert T. Kurosaka. mathematical recreations Phil Lopiccolo. computers in medicine Alastair J. W. Mayer, software Alan R. Miller, languages and engineering Dick Pountain, U.K. Roger Powell, computers and music William M. Raike, \apan Phillip Robinson, semiconductors ART Nancy Rice. Art Director Joseph A. Gallagher. Associate Art Director Jan Muller. Art Assistant Alan Easton. Drafting PRODUCTION David R. Anderson. Production Director Denise Chartrand Michael J. Lonsky Virginia Reardon TYPOGRAPHY Sherry McCarthy Chief typographer Len Lorette Donna Sweeney SENIOR EDITOR David Betz ASSOCIATE EDITORS 'IONY LOCKWOOD Donna Osgood. San Francisco MICROBYTES DAILY Dennis Barker. Coordinator. Peterborough Gene Smarte. Bureau Chief. Costa Mesa Cathryn Baskin, Peterborough Jon Erickson. San Francisco Martha Hicks Peterborough Cindy Kiddoo. San Francisco Anne Fischer Lent. Peterborough Rich M alloy, New York Lynne Nadeau. Peterborough David Needle, San Francisco Wayne Rash. Washington. 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BYTE 1986 Extra Edition • Inside the IBM PCs ft 0 •i > C ^*= — ^ >•?: JFi T* THE CHOICES. Remember when your biggest problem was no storage space in your wagon? No room for your boats, trains, cars, and planes. Your choice was to either get rid of some toys or get a bigger wagon. Now your wagon has turned into an IBM PC-XT. Your boats, trains, and cars are now database, spreadsheet, and word processing files. But your choice for more storage is still about the same: either get rid of some "toys" or get a bigger "wagon." GETTING A BIGGER WAGON. Since every bit counts, you can now upgrade your computer with a CORE 43 MB half height drive and still give yourself room to grow. IBM's standard XT contains only a 10 or 20 MB full height drive, which filled up faster than you thought it would. Your PC-XT may even accomodate 2 CORE drives. That's 86 MB and a floppy all inside the box. IBM PC-XT and IBM PC -AT are registered trademarks of Internationa] Business Machines. Inc. A SIMPLE TRANSITION. Installation is easy. Everything is supplied for you to install in less than 30 minutes. Have a drive already? Simply remove the old and slide in the new. SHIFT INTO HIGH GEAR. Our half height drives are the fastest in the world. With an average access time of less than 26 ms, these drives are 4-5 times faster than the standard XT ( and more than 30% faster than an IBM PC-AT ). Load, save, sort, and retrieve data in record time. Plus, they're one half the size! Ideal for networks and file servers, and they support both DOS and XENIX. CORE INTERNATIONAL 7171 N. Federal Hwy. Boca Raton. FL 33431 (305) 997-6055 Telex: 315 809 CORE INTL DEBE Vectra is a registered trademark of Hewlett Packard. Inquiry 76 NEVER GET STRANDED. Our read/write heads unconditionally and automatically go to a safe landing zone and lock there on power off. Unlike the factory issue XT drive ( and most others ), our drives protect you from head crashes and lost data. They'll never leave you crying. They're also fully shock mounted for your XT or even a portable computer. THE ROAD TO SUCCESS, CORE International is the world's largest supplier of high performance IBM PC-AT compatible drives. This high performance is now available in a half high form factor for other compatibles including HP Vectra, Zenith, AT&T, and the entire Compaq line. All drives are backed by a one-year warranty in addition to a choice of on-site, local, or exchange maintenance services supported by CORE and other major maintenance companies. Contact us directly or see your local CORE Authorized Dealer for details. XENIX is a trademark of Microsoft. Inc. INSIDE THE IBM PCs EDITORIAL The Struggle for Compatibility The IBM Personal Computer, intro- duced in the fall of 1981, celebrates its fifth birthday this year. With the flattery quotient nearing 1.00, the folks in Boca Raton should be proud of their progeny as the homes and of- fices of customers around the world slowly fill with imitation PCs. 1986 is proving to be the Year of the Clone. What makes building clones so easy? Why can anybody who feels like it put together a clone, rent a mailbox, and rake in a pile of cash? The key to clone building is the use of standard parts and the availability of crucial system software, like Phoenix Technology's IBM PC-com- patible BIOS and Microsoft's MS-DOS. While there are subtle incompati- bilities from clone to clone, there are usually enough similarities from machine to machine to make most clones perform acceptably as copies of the PC. This is particularly true for application software written to make DOS and BIOS calls instead of direct- ly addressing a machine's hardware. Compatibility with the IBM PC has been a contraposition for IBM. Wide availability of machines that can all run the same software has prompted the creation of thousands of programs. The availability of this software has assured the sale of machines that will run all these great programs. IBM's problem has been that other com- panies can provide this now-standard computer more cheaply than IBM. So the IBM PC created an archetype around which a flourishing industry has sprouted. Could this industry- building scenario work in reverse? TOWARD A 32-BIT BUS Standard This past spring, a group of hardware and software makers got together to talk about creating a bus standard for extending the IBM PC AT's 16-bit bus to 32 bits. The extra 16 bits would ac- commodate the Intel 80386 micro- processor as the engine for new com- puters and peripheral devices de- signed to work with the new 3 2 -bit bus. The name chosen for this new bus is Personal Computer Extended Technology (PCET). The PCET bus makes possible the construction of personal computers and peripheral devices based on the Intel 80386 processor in the absence of a standard 80386 machine from IBM. Many people speculate that IBM will either be late with an 80386- based machine or build an 80386 ma- chine that uses a proprietary operat- ing system (or maybe both). In any case, the PCET bus circumvents IBM by establishing a standard bus around which other manufacturers can build 80386 machines. A half dozen 80386 machines using the PCET bus would establish a standard that might sur- vive, regardless of actions taken by IBM. Since the PCET bus is an extension of the PC AT bus, machines built around this bus could use existing graphics and memory-expansion cards and existing versions of MS- DOS— and thousands of existing ap- plication programs. The PCET bus provides a painless way to build "turbo" ATs— machines that function like an AT but at two to three times the speed. Once an existing base of turbo Afe develops, software houses can create new operating systems— or adapt existing ones like UNIX— to tap the potential of the 80386. Hardware companies can build graphics and memory boards for a new class of workstations that are based on the 80386. Thus, a whole new genre of clones can be built, using standard, off- the-shelf parts along with adapted BIOS software and existing operating system and application programs. These new clones will actually predate the machine they are designed to replace! It seems that the personal computer world may take on an odd. ironic tilt. PCET-bus-based machines may sur- vive as a group only if IBM's 80386 machine is not an open-architecture machine. Ikndy is gambling that IBM will make an 80386 machine that can be cloned. If this turns out to be the case, any company selling a PCEl:bus computer should get in touch with an auctioneer. The obvious question arises about whether or not people really need turbo ATS. Only 13 percent of the owners of IBM computers require the power of an AT Maybe only 13 per- cent of AT owners will benefit from the power of a turbo AT. Even if this were the case, that would still create a niche for approximately 40,000 80386-based computers. But another problem is the issue of affordability. Is using an 80386 in a single-user machine a waste of hardware re- sources? Is it cost-effective? Modifications are already available for Apple's Macintosh that permit the use of an MC68020 processor and MC6888 1 math coprocessor and the addition of up to 4 megabytes of RAM. These modifications, when coupled with a IK- by IK-pixel moni- tor, transform a Mac into a high- performance workstation. But the cost is high-$7000 to $9000. Building similarly equipped turbo A'Ifc may turn out to be just as expen- sive. At that price, buyers who need a full-fledged workstation (in contrast to the folks who want to run Lotus 1-2-3 faster) might look at Sun, Apollo, [continued) BYTE 1986 Extra Edition • Inside the IBM PCs co»»» N6$s CAHH.HO^° ASlHO • 6 BOAR T, «n«?V «* -TS*1 cggiB if rm ■ It makes desktop publish a piece off cake! Tall Tree Systems introduces another breakthrough in desk- top publishing with JLASER PLUS. We've combined a 2 MB EMS memory board and an interface to both a Canon®-based laser printer and scanner. JLASER PLUS increases the perfor- mance of both devices and gives you a low- cost solution to the limitations you've been experiencing with them. Furthermore, the same memory that is made available to your printer and scan- ner is also available for all your other conven- tional applications. You get system mem- ory, expanded LIM memory, extended memory in an AT- type machine, RAM Disk and print spooler — all in a single slot! Supporting JLASER PLUS is a host of soft- ware packages, such as PC Paintbrush + *5* from ZSoft, Dr. Halo D.P.E. from Media Cyber- netics, LaserGL from Software Express, Ventura Publisher from Xerox, Page Builder from White Sciences, Le Print from Le Baugh Software, Fancy Font and Fancy Word from SoftCraft, Inc., and many more to be announced. It takes a techno- logical innovator like Tall Tree Systems to provide a major advancement like JLASER PLUS. And we don't stop at performance. We also deliver value, which is truly icing on the cake. TALL TREE SYSTEMS 1 1 20 San Antonio Road Palo Alto, CA 94303 (415) 964-1980 Canon is a registered trademark of Canon. Inc. All software packages listed are trademarks of their respective companies. TALL TREE SYSTEMS inquiry 275 ©1986 Py Tall Tree Systems. All rights reserved. Inquiry 179 INCOMPARABLY COMPATIBLE 3.5" FLOPPY DRIVE FOR YOUR PC OR COMPATIBLE Get 720K of Storage NOW On all DOS 2.0 and above. MANZANA produces a full line of 3.5" disk drive systems: • Host-powered external drives • Self-powered external drives • Internal drives All MANZANA systems come with 3FIVE™, our sophisticated but easy-to- use software package which allows you to read and write to most 3.5" formats including: IBM PC Convertible, Toshiba Tl 100 & T3100, Zenith Z-181, Atari ST, DG/One, GridCase, Kaypro 2000, HP 1 10 & 150, Tandy 600, Datavue 23 & 24, Apricot, Sony M35 & SMC-2000 Most of our systems support popular copy programs facilitating transfer between 3.5" and 5 l/4" disks. EDITORIAL MANZANA . . the Industry Pioneer in 3.5" Peripherals CALL OR WRITE FOR MORE INFORMATION, hi Canada, contact Quay Computer Corp, at (416) S90-2&4L In U.K., call Systems Constructors at 0202-297315, Come sec us at Comdex/Fall Booth 734 at the Ballv (irand MANZANA1" MicroSy stems, Inc. P.O. Box 2117 Goleta, CA 93118 (805) 968-1387 1-2-3 faster) might look to Sun, Apollo, DEC, or IBM's RT PC for more stable hardware and software. The one application area that can potentially benefit most from 80386 performance is graphics. Intel's new microprocessor can permit the crea- tion of workstations with a great deal of graphics power. But the trend in graphics processing is to offload graphics to its own processor, either custom-built, as in the Amiga, or off- the-shelf parts, like the 7£xas In- struments TMS34010. There is also the problem of the 16-bit EGA stan- dard and how it can be adapted to a 32-bit environment. Technology Driven Regardless of the need for 80386- based machines, technology has a way of evolving for its own sake. Peo- ple need to find out what is possible, whether it be with airplanes or com- puters. Therefore, the PCET-bus specifica- tion effort makes sense from a re- search and development point of view. It establishes a common starting ground for machine designs using a new processor. The PCET-bus design goals seek to provide a high-speed bus for 3 2 -bit memory and memory-mapped data transactions. The bus also needs to be flexible enough to permit 3 2 -bit co- processor cards to become alternate bus masters. The PCET bus pipelines address and control information, making this information for a subsequent bus cy- cle available in the latter stages of the current bus cycle. The bus design calls for a default to two wait states but can be operated with one or no wait states by activating additional control signals. Compatibility with the existing 16-bit PC AT bus is a must for the PCET bus to take advantage of exist- ing graphics and memory standards. (An interesting outgrowth of the PCET- bus specification effort is that the committee first had to codify the AT bus.) A mix of 16- and 32-bit bus masters can drive the PCET bus to ac- commodate refresh, direct memory access, and other tasks. The memory map for the PCET bus shows the entire 4-gigabyte address space of the 80386 as being available to the bus, except the 640K-byte to 1 -megabyte area reserved for ROM and video devices. Mechanically, the PCET bus extends the data lines of the PC AT bus by 40 pins. The data lines on the RT PC bus, already 40 pins instead of 36 as in the AT also get another 40 pins. We still need to ask some legitimate questions about the PCET bus. Is it possible to achieve nearly the same 80386 performance on a 16-bit bus feeding a 32-bit cache? Since 85 per- cent of all CPU operations are read operations, caching operands may allow an 80386 to operate almost as fast with a 16-bit bus as it would with a 32-bit bus for some applications. Another question about a 32-bit standard bus: What if companies ig- nore it and create their own bus? There have been widespread reports of 80386-machine projects at Com- paq and Zenith that will feature pro- prietary 3 2 -bit bus designs. The PCET bus, no matter how elegant its design, will fade away like the dodo if every- one ignores it. Another Round Regardless of the creation of the PCET bus, there will be new machines built around the 80386. The early machines will be expensive and will have no software to fully exploit their power. They may serve as a bridge from the current PC world to a future 80386-machine-based environment. These new machines will undoubted- ly raise a different set of compatibili- ty problems with the machines and software that preceded them. But we'll buy them anyway. — G. Michael Vose Senior Technical Editor Look for IBM-related conferences and special events on BIX starting in late October. Current plans call for a special event on "System Software for the 80386," plus con- ferences on the RT PC and the PC Convertible. BYTE 1986 Extra Edition • Inside the IBM PCs ^ w The Most Powerful LAN Fits on a Disk. Network Rawer. \bu knew that someday there would be a powerful LAN that dldnl need old-technology network boards. It would be fast, easy to install, and run 99% of PC- DOS software. It would be expandable; provide remote access, password-protection, and enable you to use Inex- pensive terminals as workstations in a PC-DOS environment. Dream no more; because the power is here. Its name is LANLink^ A Software-Driven LAN Powerful Enough To Use RS-232 Ports for Network Communications, In development for over three years, LANUnk™ represents the next generation of local area networks. All of the logic which has traditionally resided on network boards is onlANLink's Satellite and Server Diskettes. No additional hardware is required. Inexpensive serial ports replace "Kilobuck" Network Interface Boards making Installation costs one-third that of a board-driven network. How To Configure a Smart Network... With Dumb Terminals, But Without Dedicated Servers. Boosting a wide variety of configurations. LANLink™ is most often set up as a "Star" having up to eight satellites connected to a cen- tral, nondedicated server. Larger networks can have multi- ple servers, supporting a total of 73 or more network users. [MAN™ (Remote-LAN) gives users the ability to interact with a LANLink™ network in real time via modem. Plus, if MulfiLink Advanced™ is run on a Satellite, inexpensive dumb terminals can be used to access network disks, files, and programs. THE SOFTWARE LINK, JNCv/CAMADA 250 Cochrane Drtoa Suite l£ Markham. Ontario L3R SB7 CAUj 416M7T54S0 LANUnk^MurUUnk Advanced1*1 & fl-LANwara trademarks or The Software Link, Inc. IBM, PC, & PC-DOS are trademarks of I0M Corp. WordStar 2000, dBASE til, and Lotus 1-2-3 are trademarks of WordPro, AsHtory Tate, and Lotus Development Corp,, respectively. 99% of PC-DOS Applications Run In a Totally- Transparent Network environment If you know DOS, you air dy know how to use LANLink?1* COPY transfers files among users, and a 2-drive PC Satellite boots 1-2-3 from the Server's hard disk with the entry crlotus. Each satellite's access can be limited to specific disks, printers, and su directories. A wide variety of software Including Lotus 1-2-3, dBASE III, and WordStar 2000 is fully compatible. LANLink™ has a collision-free data transfer rate which exceeds 115.000 BP& Power Up Your PCs Today. For complete details and the authorized dealer nearest you, call The Software Link TODAY The LANLink™ Starter Kit is $495 and includes modules for both a Server and a Satellite. For a limited time^ 50 feet of shielded RS-232 cable will be included free of charge. Additional Satellite Modules are only $195, each, LANLink™ is immediately available and comes with a money-back guarantee. VISA, Ma AMEX accepted. Inquiry 263 THE SOFTWARE LINK, INC. Developers of LANUnk^and MuitiUnk Advanced1* 8601 Durwoody Place, Suit© 632, Atlanta, GA 30339 Tetex 4996147 SWLINK CALL: 404/998-0700 Dealer Inquiries Invited Use the Brains your IBM Wasn't born wtra Right at your fingertips in CompuServe's IBM® Forums. In the IBM New Users Forum you'll swap ideas with other new PC users, learn to use Forum features, and pose even basic questions to PC experts. Our IBM Junior Forum gives PCjr® users a reliable source for tips on software, hardware, telecommunications, games and other interests. In the IBM Software Forum you'll trade tips with other IBM PC and AT users on utility software, word processing, DOS and other operating systems. Visit the IBM Communications Forum for advice on the features and compatibil- ity of communications software and hardware, PC Bulletin Boards, micro- mainframe interfaces and more. The IBM Hardware Forum addresses hardware topics of all types, plus product updates and announcements. Easy access to free software. • Download first-rate, non