II Computing Vol 1 No 1 Oct Nov 85 Premiere

FOR APPLE II USERS | (COMPUTING U.S.A. $2.95 CANADA $3.50 OCTOBER/NOVEMBER 1985 PREMIERE ISSUE Look! en Up in the sky > It’s Halley’s Comet plot the orbit Z-RAM for the IIc Pro Football Prognosticator College Credit On Line Spreadsheet Horrors How to avoid them Computer Frontiers {| 17795 10 Why every Kgs should have an Apple afte Today there are more Apple® computers in schools than any other computer. Unfortunately, there are still more kids in schools than Apple computers. So innocent youngsters (like your own) may have to fend off packs of bully nerds to get some time on a computer. Which is why it makes good sense to buy them an Apple Ic Personal Computer of their very own. Send them home to a good school system. The IIc is just like the leading computer in education, the Apple Ile. Only smaller. About the size of a three-ring note- book, to be exact. Of course, since the IIc is the legitimate of spring of the Ile, it can access the worlds largest library of educational software. Everything from Stickybear r school. Shapes” for preschoolers to SAT test preparation programs for college hopetuls. In fact, the IIc can run over 10,000 programs in all. More than a few of which you might be interested in yourself. , For example, the best-selling, AppleWorks" 3-in-l integrated soft- ware package. Personal finance and tax pro- grams. Diet and fit- ness programs. Not to mention fun programs for the whole family, Like“Genetic Mapping’ and “Enzyme Kinetics’ One Apple that won't leave them hungry The Apple IIc is easy to set up and learn. And it comes com- plete with most everything you need to start computing in one box. Including a free, easy-to- use 4-diskette course to teach you all about the IIc—when your kids get tired of your questions. As well as a long list of built-in features that would add about $800 to the cost of a smaller-minded computer. The features include: 128K of internal memory— as powerful as the average office computer. The ImageWriter II prints high quality color graphics. A built-in disk drive that could drive up the price of a less-senior machine considerably. And built-in adaptors for adding accessories, like our new ColorMonitor IIc, Image- removing the sprocket paper” If local color isnt enough, Writer" II printer and the Apple you can talk to the rest of the Personal Modem 300/1200. A feast for their eyes. The big 14-inch ColorMonitor lc displays crisp, color graph- ics or a high resolution 80- column monochrome text for word processing. You can print sharp color graphics, too, with our new ImageWriter IL. It also prints And speaking of high quality color, introducing ColorMonitor Ilc. near-letter-quality text in black and white, quickly and quietly. And, with its new SheetFeeder, you can switch to single sheets without The most popular peripherals plug right into the back of the Apple Ic. world through our new wall- mounted Apple Personal Modem 300/1200. With it, you can do your banking at home, check your stocks, gain access to all kinds of information libraries and much more. Which would all add up to avery impressive list of expand- able accessories if it werent for all the others. Like an Apple- Mouse. And an extra disk drive when the time comes. Avoid growing pains. So while your childrens shoe sizes and appetites continue to grow at an alarming rate, theres one thing you know can keep up with them. Their Apple IIc. To learn more about it, visit any authorized Apple dealer. Or talk to your own computer experts, As soon as they get home from school. = @. * Optional accessory may be purchased for ImageWriter I, © 1985 Apple Computer Inc. Apple and the Apple logo, AppleWorks, and Imageliiter are trademarks of Apple Computer, Inc Stickybear Shapes is a trademark of Optimum Resource. Foran autborized Apple dealer near you. call (800) 538-9696. In Canada, call (800) 268-7796 or (800) 268-7637. How to get the most bytes out of | your Apple. Read why Steve Wozniak recommends RamWorks™ expansion cards. Tk machine that Woz built is a powerful business computer. AppleWorks gave it a potent 1-2 combination. Now, RamWorks has added the knock out punch, With RamWorks expand the total memory of your Ile up to an incredible 2.5 MEG. Your AppleWorks will no longer be limited by the amount of factory supplied RAM. And you'll be able to perform virtually any application you want with far greater speed and ease. programs written for them without modification RamWorks was designed so you could take full advantage of future developments in 16 and 32 bit microprocessors. As your needs grow, so can RamWorks. A handy expansion connector allows the latest and greatest co-processor cards to access RamWorks’ memory. And allows you to piggyback another 2 MEG. Clear instructions show you how to plug in more memory. For only $129 you can add an RGB option to your RamWorks and get double high resolution color graphics. All with a super sharp brilliance that’s unsurpassed in the industry. How AppleWorks works best with RamWorks. RamWorks plugs into the Ile auxiliary slot and acts just like Apple’s extended 80 column card, If you buy a 256K or larger card, AppleWorks will automatically load itself into RamWorks. This dramatically More features than you can shake a increases AppleWorks’ speed because it a é | mouse at. effectively eliminates time required to access Aword from the Woz should be sufficient disk Drive 1. Now, switch from word pro- Because there's only one card like cessing to spreadsheet to database manage- T wanted A MeMOLY _ Ramvorks. imagine how you will benefit ment at the speed of light. AppleWorks card for my Apple that _ from these features: + 15 DAY MONEY BACK responds the moment your fingers touch aa GUARANTEE * Sharp 80 column text (with the keyboard, was fast easy 10 USC, without RGB option)» Double high But AppleWorks has certain internal and very compatible; so _ resolution graphics (with or without RGB limits, independent of available memory. ” option) * EXPANDABLE TO 2.5 MEGABYTES Fear not. Only RamWorks removes those I bought RamWorks” year ise 64K or 256K RAMs in any limits with a proprietary, easy to operate combination + Adds memory to AppleWorks program that “patches” onto the boot disk + Co-processor connector + Accelerates in seconds. Only creases the speed of AppleWorks * 100% COMPATIBLE maximum number of re ilable WITH ALL Ile SOFTWARE * RAM disk to you from 1,350 to over 5,000. And only software available (compatible with RamWorks actually increases the number of Applesoft, PRO-DOS, DOS 3.3 and PASCAL— lines permitted in the word processing mode. $29) * RAM disk available for CP/M ($29; is, when you create an AppleWorks file larger than your disk included with our CP/M card) * RGB color option « Takes only nly RamWorks automatically segments it to the appro- one slot ¢ FIVE-YEAR NO HASSLE WARRANTY. priate size. RamWorks then prompts you to insert more disks, so RamWorks with 64K ($179); 128K ($219); 256K ($249); 512K you can save any size file on regular floppies or hard disk. ($319); 1 MEG ($519); 2.5 MEG ($1599). CALL 214/241-6060 TO ORDER YOUR RamWorks TODAY. (9 a.m. to 11 p.m. 7 Days, or send check or money order to Applied Engineering, RamWorks is compatible with more off-the-shelf software MasterCard Vistand © OD iwelconieTesas resides add Sie than any other RAM card. Popular programs like Magic Office sales tax, Add $10.00 outside US.) System, Flashcalc, The Spread Sheet, Diversi-DOS, Supercalc 3A, The most friendly, most expandable card available. Magicalc, etc. (And hardware add-ons like Profile and Sider hard y= i A i disks.) Fact is, RamWorks is 100% compatible with all software Applied Engineering written for the Apple 80 and extended 80 cards. In addition, P.O. Box 798, Carrollton, TX 75006 RamWorks can emulate other RAM cards, so you can use (214) 241-6060 FOR APPLE II USERS COMPUTING Volume 1, Number 1, October/November 1985. If Computing—For Apple II Users is published bimonthly by Antic Publishing, Inc. Editorial offices are located at 524 Second Street, San Francisco, CA 94107. Second class postage applied for at San Francisco and additional mailing offices. POSTMASTER: Send address change to I! Computing, P.O. Box 1922, Marion, OH 43306 FEATURES 36 Education: College Credit On Line 16 Track Halley’s Comet by Paul Cohen ‘ by Donald Tattersfield 5 E Where To Look, When To Look 43 Reviews: E Kermit’s Electronic StoryMaker; E 32 Spreadsheet Horrors The Speller; Newsroom & Print a by Robert Freeman Shop; Visible Pascal — And How to Avoid Them . E 0 44 Sneak Preview: | 40 Pro Football Hardware m3 Prognosticator Z-RAM from Applied by William Marquardt Engineering Beat the Spread With Your Apple i 45 Sneak Preview: 24 For the Fun of It Software by Neil Shapiro Fantavision from Broderbund Games & Entertainment A Software 53 For Kids: Ladybug Color 27 Tales From The Crypt by Caxton C. Foster Drawing Program Cracking Ciphers with by Steven Koepke Computers 79 Graphics: 39 Sotto Voce Color Weaver by Margot Comstock by Gerald Hagopian Reflections by a Former Softalk Editor SOFTWARE LIBRARY 58 Type-In Listings READER SERVICES 6 Editorial Brave New Words DEPARTMENTS 11 Profile: Christopher Cerf, Creative Catalyst by Michael Ciraolo 19 Assembly Language: New 65C02 Instructions by Morgan P. Caffrey 23 Game Frame: 8 Perspectives: : Whither Apple? Ecto Blasters by DeWitt Robbeloth by Stephan Schwirzke DE ee eat ae COLUMNS 51 Top Software Charts 30 Power Programming: 3 ALI 15 Computer Frontiers 52 o II Text Handling in by James Capparell type Ghecken Hi-Res Cutting Edge of Computer by William V. R. Smith Technology 82 New Products FOR APPLE Il USERS OMPUTING Publisher James Capparell Editorial DeWitt Robbeloth, Editor Anita Malnig, Assistant Editor Gerry Villareal, Tichnical Assistant Rebecca Hale, Editorial Assistant Art & Production Marni Tapscott, Art Dinctor Diane Lindley, Production Supervizor Linda Tapscott, Ad Production Coordinator Julianne Ososke, Production Assistant Cover Artist Dave Jensen Contributing Artists Beatrice Benjamin, Alan Okamoto, Paul Ollswang Circulation Les Torok, Manager Hun-sik Kim, Shipping Eve Gowtley, Dealer Sales Brandt-Klingel, Cireulation Consultants Marketing Gary Yost, Director Lisa Wehrer, Mer. Product Distribution Brad Kershaw, Product Specialist Administration Clay Selland, Contaler Lorene Kaatz, Credit Manager Andrew Pope, Retail Service Brenda Oliver, Accounts Receivable Griselda Frias, Accounts Payable Nelly Rodriguez, Data Processing Fidez Bituin, Clerk Tpist Advertising Sales ‘John Taggert, Director Steve Randall Harvey Bernstein Leslie Bouffard Garland & Associates Receptionist — Maria Chavez General Offices and Catalog Customer Service (415) 957-0886 Subscription Customer Service (614) 383-3141 Advertising Sales (415) 661-3400 Garland & Associates (617) 749-5852 Credit Card Subscriptions & Catalog Orders outside California (800) 227-1617 ext. 700 inside California (800) 772-3545 ext. 700 Editorial submissions should include program list- ing on disk and text on disk and paper if prepared with a word procesor. Media will be returned if self-addressed stamped mailer is supplied. Antic Publishing assumes no responsibility for unsolic- ited editorial material No part of this publication may be stored in an elec tronic retrieval system except by the purchaser for his own use, nor reproduced by any means (elec tronic, magnetic, mechanical, optical, photo- graphic, or other) by anyone without prior written, permission of the publisher. I Computing — for Apple IT Users is an indepen- dent periodical not affliated in any way with Apple Computer, Inc. Apple, Apple IT, Apple II+, Apple He and Apple //c are registered trademarks of Apple Computer, Inc. All references to Apple prod- ucts are trademarked and should be so noted. POSTMA‘ Send address change to II Computing, PO. Box 1922, Marion, OH 43306. Copyright 1985 by Antic Publishing, Inc. All rights reserved, Printed in USA EDITORIAL Brave New Words Thanks for giving us a chance to introduce ourselves. IT Computing is a new magazine specifically for those of us who own or use some type of Apple II computer. That in- cludes the II, II+, IIe and IIc and all future computers built around the TI design. We'll also cover the peri- pherals, software and firmware for Apple II machines. Browse through this issue and you will see a mix of informative articles and useful, entertaining programs. We are especially proud to offer you the work of two prestigious authors, astronomer Donald Tattersfield (Halley's comet program) and com- puter scientist Caxton Foster (on cryptanalysis), plus two old friends of yours, Margot Comstock Tom- mervik (of Softalk) and Neil Shapiro (SYSOP of CompuServe's MAUG). Our program lineup also includes “Pro Football Prognosticator;’ which we hope will be more than useful to you. If you prefer not to type in the programs by hand, we offer an at- tractively priced companion disk with the programs already on it. Ask your retailer for details, or call our toll-free number listed on the enclos- ed subscription order form. You may be curious about our bravery (or foolhardiness) in laun- ching a new computer magazine when computer mania seems to be at an ebb, and about our dedication to machines from a company so recently buffeted by internal strife. Well, it is a gamble, but we believe a sound basis exists for taking the chance. Our most important prem- ise is that the computer revolution isn’t over, it has hardly begun! Maybe the fad days are over, but for substantial numbers of us, working and playing with our computers will remain an integral part of our daily lives for years to come. As for supporting Apple IT com- puters, why not? You have one, I have one, and so do a couple million other people. The II’s are fine, ver- satile machines, well supplied with software and peripherals, and still in production from the company that virtually invented _ personal computing. We have confidence in Apple, but even if the company were to falter, that doen’t mean your computer would self-destruct. In some ways, trouble at Apple makes a magazine like ours even mor valuable to you. Valuable to you—that’s what we must be to succeed. If we give you your money’s worth each issue, I think we will have a long, pleasant association. What does value in a magazine mean to you? We think it means: useful, stimulating, chal- lenging, helpful, convenient, eco- nomical, informative, pertinent, at- continued on page 8 LORRAINE CAPPARELL I COMPUTING ‘Superstars aren't just the best in their fields. They're the best, year after year. In the wide world of sports simulations, SSI's COMPUTER QUARTERBACK™ and COMPUTER BASEBALL™ stand out as true superstars. To date, tens of thousands of enthusiastic fans and dozens of maga- zine reviewers alike have cheered their ‘superb display of realism and excitement. By consistently outplaying the competi- tion, our games stand head and shoulders above the crowd. If you're scouting for the best football and baseball strategy games around, take a good look at ours — the ones with the proven performance. You'll know these are the superstars you want to play on your ‘computer. Sign them up at your local computer/software or game store today! If there are no convenient stores near you, VISA & M/C holders can order these $39.95 games direct by calling 800-227- 1617, x335 {toll free). In California, 800- 772-3545, x335. Please specify computer format and add $2.00 for shipping and handling. To order by mail, send your check to: Strategic Simulations, Inc., 883 Stierlin Road, A-200, Mountain View, CA 94043. (California residents, add 7% sales tax.) All our games carry a “14-day satisfaction or your money back” guarantee. WRITE FOR A FREE COLOR CATALOG OF ‘ALL OUR GAMES TODAY. Computer Quarterback is on diskette for 48K APPLE II series, ATARI® home computers, and the COMMODORE 64 Computer Baseball is on diskette for APPLE, ATARI, C-64 and IBM PC® and PCI. APPLE, ATARI, COMMODORE 64 and IBM PC/PCjr are trademarks of Apple Computer, Inc, Atari, In, Commodore Electronics, Ltd, and international ‘Business Machines Corp, respectively STRATEGIC SIMULATIONS, IN PERSPECTIVES BRAVE NEW WORDS continued from page 6 tractive, amusing, profitable, plea- surable, clear, accurate, diverse, and personally enhancing. These are the attributes we strive to achieve in IT Computing. That's a tall order. We know your standards are high, but we are deter- mined to meet them. We want I Computing to be your most welcome companion at your Apple keyboard. We are not competing with other magazines, we are serving you. If you get what you want from us, the competition will take care of itself. Your ideas and suggestions are always welcome. // Dh bte Rabbit DeWITT ROBBELOTH, EDITOR FOR BASIC SKILLS INSTRUCTION SIMPLICITY SUPPORTS SUCCESS! Centurion software programs present les- son material in a straightforward, con- tent-oriented format. No distracting “video game" embellishments compete for attention. Centurion Software pro- grams are even more exciting and motiva- tional because they allow students to compete with themselves, not the com- puter, while gaining skill mastery. Centurion software combines microcom- puter versatility and proven learning principles to provide both interactive an high-speed drill practice learning oppor- tunities. We have the largest, most com- prehensive library of software supporting mastery level learning of Basic Reading, Spelling and Mathematics. Grades K-12. EDUCATIONAL SOFTWARE — BEST FOR BASIC SKILLS — Order either Mixed Math Exercises or Word Unscramble (Grades K through 8) for the sale price of $29.95 (Reg. $39.95) and get our catalog free. (Each Centurion Software Program includes the program diskette, a detailed Learning Guide and a printed Diagnostic/Test Lesson.) Check or money orders only: Name. Address. City. State. Zip. Mail to: Centurion Industries, Inc. 2000 Broadway, Redwood City, CA 94063 Allow 3 weeks for delivery Whither Apple? by DeWITT ROBBELOTH, EDITOR The computer world was stunned in. June when Apple Computer, Inc. announced, in effect, that cofounder and Chairman of the Board Steven Jobs had been unhorsed in a cor- porate joust with Apple’s President and Chief Executive Officer, John Sculley. Sculley convinced the Board of Directors to reorganize the company in a way that removed Jobs from his executive role as general manager of the Macintosh Division. The new “functional” organization did not in- clude a managerial job for Jobs. Of course, he remains as Chairman and major stockholder, and is now char- acterized as “chief visionary” for the company. Most industry savants agree the move was good for Apple, or even crucial. Why? There were serious, fundamental differences between the two about what Apple products should be like, how they should be marketed, and how the company should be run. (What else is there?) Jobs and cofounder Steve Woz- niak epitomized the boy-genius entrepreneurial style. In Apple’s 1984 Annual Report, Jobs appears con- spicuously coatless amid his sar- torially staid executive staff. Having achieved the American dream, Jobs was seen as “cocking a snoot” at cor- porate traditions, according to Apple-watcher Paul Evans of the securities firm S.G. Warburg, Rowe & Pitman, Akroyd. Seemingly at odds with the con- cept that had made the Apple IT such a success, Jobs advocated the closed- box approach to products, with most resources backing the Mac as a business machine to challenge the IBM PC. Sculley favored open, ex- pandable product lines like the Apple II, aimed at soaking up sales where IBM's corporate clout wasn't devast- ating—in education, small busi- nesses and the home. With Jobs in the Macintosh sad- dle, Sculley apparently had little con- trol over half the company. Finally, the failure of the Mac to significantly dent IBM’s armor resulted in losses that gave Sculley a good business reason to challenge Jobs’ control by reorganizing. Apple’s former organization divided the company along product lines—Apple II on one side, Macin- tosh on the other. It was really two companies running side by side, with some glaring duplication of services. The new organization is functional, with sales and marketing on one side, and product operations, includ- ing new product development, on the other. Now what? At his first public ap- pearance since the coup (at Future Computing’s MacForum in San Francisco), Sculley assessed the situation. Apple is still healthy, he said, and will be trimmer after the reorganization. A more disciplined approach to business enacted by Apple’s many good managers and some new outsiders will concentrate on selling all Apple's existing prod- ucts primarily through dealers (as opposed to direct sales by the Apple sales force). continued on page 10 1 COMPUTING There’s More to Managing Your Money Than Dollars & Cents The Home Accountant The all-time #1 best-selling home finance package. The Home Accountant will wisely manage your money on a daily basis as well as plan your financial future. The Home Accountant lets you flag trans- actions for tax time, print net worth and other financial statements, handle multi- ple credit cards and checking accounts PEsgeRenest and can have up to 100 budget categories. i Available for Apple !l/lle THE HOME ACCOUNTANT” ‘nd Financial Panne forthe Macintosh % yee The Home Accountant Expanded Designed for each of use on Apple Ilc/Ile computers. Beside all the great Home The Home Accountant and Financial Planner for the Macintosh Accountant features, the new ProDOS feature provides speedy and accurate disk access, amemo module for appointments and pending bills, and 80-column display. “Home Accountant is considered the granddaddy of personal finance packages.”"—San Jose Mercury News Voted ‘Best Software of the Year’ by A+ readers. The Home Accountant” FCM FCM (Filing, Cataloging, and Mailing) is the perfect mailing list manager for your personal computer. Prints mailing lists and labels, and it’s terrific for other applications such as organizing your record collection or keeping track of party guest lists. One of the few programs designed for the Macintosh that fully employs its unique capabilities. It’s great for running a small business or for department project accounting in a large business. The Home Accountant and Financial Planner for the Macintosh will enable you to wisely man- age your money on a daily basis as well as help you plan your financial future. FCM. Get Rich: Financial Strategies (Module 1) It’s a competitive world. Do you have the financial tools to survive? Get Rich, a handy “reference” program, will give you the right tools to organize your finances. Real Estate Planning (Module 2) For most of us, a home is the biggest investment we ever make. Don’t make a mistake! Consult Real Estate Planning. Insurance Planning (Module 3) We insure our cars, our homes, and our lives, but are we properly covered? Is there a less expensive way? Insurance Planning concentrates on different types of insurance, including life, social security, disability, property, auto, and health. Arrays, Inc. ® 6711 Valjean Avenue @ Van Nuys, California 91406 @ 818-994-1899 WHITHER APPLE continued from page 8 The vision for Apple remains the same, Sculley said. “Apple builds personal computers for individuals, not institutions.” There will be new Apple products, but their develop- ment will be “market driven.” He urged his listeners to stop focusing on “what comes next, and look at what we have to offer people today.” Nevertheless, there will be new products. Sculley firmly supported continuing production and develop- ment for the Apple IT line and en- couraged other companies to jump on Apple’s bandwagon. He specifi- cally instructed Apple’s legal and marketing groups “to Build bridges with outside software and hardware developers, to make it easier for them to work with Apple.” One widely rumored direction is towards the 65C816 chip. This microprocessor from Western Design Center operates in cither of two modes. In emulation mode it works identical to the 6502 or 65C02 chip, so it could maintain com- patibility with existing Apple II soft- ware. In native mode it operates as a 16-bit (or 8-bit) processor and will need new software, but can directly address 16 megabytes of memory (about the same as most main- frames). An operating system for this chip's native mode is being designed that will do for it what CP/M did for the Z-80. The Apple II market continues strong. Future Computing, a research firm, pegs Ie sales in 1984 at about 500,000 units and holding steady, with Ic sales expected to sur- pass that number in 1985. Even if demand is only half that much, it would still indicate substantial inter- est-in this venerable line of com- puters. There are good reasons for this. The open architecture of the IT line continues to stimulate third- party development of hardware and firmware, while a vast library of soft- ware and established user networks help retain the loyalty of Apple II owners. It seems the furor has settled down, but there are still doomsayers. Robert Lydon, publisher of Personal Computing magazine, predicts that Apple Computer, Inc. will not last as a separate company for another two years. As for the home market, “Tt never really existed,” he says. “It was a fad. Just about everyone who was going to buy a computer for their home has done it. And my guess is that most of the computers actually used at home tie in with some business use” Paul Evans, on the other hand, thinks Apple will make it. “It’s a big company, and now it's going to be run like one. It has viable products and a great reputation. There’s room in the market for Apple. It’s going to take a bad quarter or two and write off a lot of problems, then come back strong this Christmas. No question in my mind, Apple will be around a long time.” // COMING NEXT ISSUE: Charles Rubin on “The Ilc As A Business Machine” Muppet Key Software Round-Up High-Tech Toys Analyzing Your Skiing Style Create Your Own Holiday Cards More From our columnists: Comstock, Shapiro, Foster, Capparell. . . Plus: Free Software, Activities for Kids, Bestsellers. . . I COMPUTING [Rourvtine No More Typing SEASONS SPECIAL CHARTER RATE! r] HA RATE! pra hl Action Edition includes Action Disk of software with every issue. : Il Computing YE |] Send me 6 issues of II Computing : m= Action Edition at the special a To. introductory price of $59.95. | understand that every FREE (OD) issue includes a diskette with all software ready to 24 load and go. hours-a-day O Check enclosed 1 Bill my creditcard O VISA CMC 800 Name Co. 227-1617 Address ext. 700 City State Zip (in Calif. Credit Card # AOp-722: 8545 Exp.Date____——_- Signature EKS4 Please allow 4-6 weeks for delivery of your first issue. All Foreign subscriptions add $25.00 per year. ORDERS ONLY! 5 5 ae Charter rate [ OMPUTING over 35% off newstand SPECIAL CHARTER RATE! : ES m Send me 6 issues of // Computing at the special introductory (charter) subscription rate of $11.97. © Check enclosed © Bill me Name Company Address City State Zip Please allow 4-6 weeks for delivery of your first issue. Canadian and Mexican residents add $5.00 Per year. Other Foreign subscriptions add $10.00 per year. i i | I | I ! I I ! ! | ! ! | I l I ext. 133) f ! ! ! | | ! ! | | 1 | 1 l 1 ! I ! | ! ! ] l i] i] BUSINESS REPLY MAIL FIRSTCLASS PERMITNO.645 MARION, OH 43306 POSTAGE WILL BE PAID BY ADDRESSEE [ompvtine- ll Computing PO. Box 1922 Marion, OH 43306 NO POSTAGE NECESSARY IF MAILED IN THE UNITED STATES as BUSINESS REPLY MAIL PERMIT NO.645 MARION, OH 43306 POSTAGE WILL BE PAID BY ADDRESSEE FOR APPLE Il USERS COMPUTING “ {| Computing PO. Box 1922 Marion, OH 43306 NO POSTAGE NECESSARY IF MAILED IN THE UNITED STATES CHRISTOPHER CERF, CREATIVE CATALYST Moves Muppets into software by MICHAEL CIRAOLO Christopher Cerf is a joy to be around. He's a bright, bubbling man whos always in motion— not with manic energy, but with the enthusiasm of someone who can’t stop having a good time. It isn’t easy to capture Cerf on paper. It would be easy to simply say he helped launch the Na- tional Lampoon, designed award-winning software, earned wide acclaim as a writer and editor and won two Grammy awards, one for “The Electric Company” score. Nor would it do justice to his creativity, genius and energy to blithely describe his latest contributions to the Muppet Learning Keys, Kermit’s Electronic StoryMaker, or other software reflecting a 16-year association with the Muppets. tion because he transcends conventional levels of energy and enthusiasm. More than anything else, he likes to have fun. Fortunately, for Apple computer owners, the 42-year-old “Renaissance Kid” has brought his sense of fun to software, in the guise of Jim Hen- son's familiar Muppets. The teams of Henson Associates (HA!) and Christopher Cerf Associates, both of New York, jointly produce software con- sidered educational, though it is far removed from traditional drill-and-practice software. The association started shortly after the begin- funny. . .and useful —a little bit of music, educa- tion and humor” At the time, he worked for Random House’s Beginner Books division, pub- lisher of Dr. Seuss. Excited by the potential of “Sesame Street,’ Cerf joined the multimedia divi- sion of Children’s Television Workshop (produce of “Sesame Street”) the following year. It was there that he met Jim Henson. They collaborated on many successful projects in a variety of media: books, games, toys. “We wanted to do something unusual, unique, useful and state-of-the-art. We Christopher Cerf defies conventional descrip- | ning of “Sesame Street” in 1969. Gerf was already | “hopelessly hooked on doing things that were [§ Gi wanted to be at the cutting edge in something we enjoyed.” Cerf and Henson started, among other projects, M._LT., the Muppet Institute of Technology, where the motto is “Learnum est Funum.’ One of the first M.L'T. products was the Muppet Learning Keys, a colorful, oversized keyboard with numbers, continued on next page OCTOBER / NOVEMBER 1985 letters in alphabetical order, and Stop, Go, Erase and Oops functions. The keyboard plugs into Apples or other computers and is now being sup- ported by other software adapted to work with the Learning Keys. The Learning Keys, named one of the products of the year (1984) by InfoWorld, sold an impressive 60,000 units during its first year. THE BEST PEOPLE When you talk to Cerf about his contributions, he stresses not his accomplishments, but the nature of the team to which he lends his talents as coor- dinator and catalyst. That team is composed of the best people available, according to Cerf. “You don’t teach someone new. You go to the best.” This group of Henson Associates, Cerf Associates and individuals from various publishers is one team — “you can't tell who's working for whom, when it’s working” ‘There are two ways to produce software, accord- ing to Cerf. The first, traditional approach, is to come up with an idea, write a program to repre- sent that idea, and then sell the package. Cerf prefers a second approach, which helps define his role in creating and developing software. Cerf describes his role as that of coordinator, sup- plying creativity and acting as a catalyst. Making excellent software products is akin to producing a movie or a children’s book, wherein, for exam- ple, “The writer doesn’t do everything. You need an illustrator, who can communicate with the author, a cover illustrator and someone to keep all this from becoming too expensive.” Similarly, he says, “A good educational program has clear and well-written text, animation that is effective and a good sense of movement. You want entertaining pacing and the best mus puter can support. Bring all this together with education on the top. The general rules are that you take the best people available who have fun working together, people who are goal-oriented, and you end up being funny and silly and creative” Since few people are top-notch at all the aspects involved in producing state-of-the-art software, Cerf’ team includes writers, animators, artists and programmers. It also includes pioneering computer educators, some of the original Muppet illustrators, ex-Disney animators and former National Lampoon staffers. None of these people are confined to the bounds of their professions—each team member must understand how the group fits together and under- stand the process, so that each request to other members is realistic. Christopher Cerf Associates have made some in-house developments that contributed to the > the com- larger Henson/Cerf team. One such effort was a technique for digitizing illustrations into Apple pro- grams. This enabled them to bring in illustrators who didn’t necessarily have computer experience. COMMITTED TO HAVING FUN Cerf believes that “if you can do something enter- taining and educational, kids will learn. Products have to be entertaining — people have to choose to use the software. “You should be able to explore what you want in the computer, not what the programmer wanted... Early educational software would ask Johnny, what's the capital of Pennsylvania?” and if he couldn't answer, he'd be there all day. Pro- grammers should keep computers from being aggravating” Explorable software lets you change one variable at a time, so that you can understand what your command did. The change, according to Cerf, should change both a sentence and the animation on the screen (in a typical Muppet program). “The ability to change one variable and see the result gives children a sense of total control and power over the program.” Cerfs understanding of kids comes not from parenting—he hasn't —but from understanding his own sense of fun and curiosity. The entertaining nature of Cerf’s software does more than teach. It also sells programs in a sensi- ble, old-fashioned way. “You can’t just throw money at something to have it sell — products have to sell themselves. It has to be word of mouth between kids and parents.” A QUIET TIME? Some would say it is foolish to design software and even introduce products when the entire industry is approaching a standstill. But Cerf has no pa- tience for those who claim the home-computer market is dead or software sales are “flat” “I just want them to go away! Alll the gadget freaks bought computers, and the industry produced 411 nearly identical programs, all with the same ads. We're growing naturally, and that may be slow.” A slow market doesn’t bother him. “It's nice to have some quiet time. We're in a quiet time right now.” Indeed, Cerf is looking beyond the quiescence to things he'd like to see in educational software. “The next big breakthrough in educational soft- ware is sound. Imagine a program that could read a sentence (from StoryMaker) to you. Fd love to hear a character say the letter or word, as it ap- pears on the screen, in the voice of Kermit, not in conventional speech-synthesizer noises.” Although Cerf won't discuss his long-range plans, I. COMPUTING he is willing to talk about some of his upcoming Collaborating with author, humorist and ex-bodyguard Douglas Adams, who wrote the Hitchhikers Guide to the Galaxy (as well as related books, radio show and software), Cerf is working on a conversation program that lets you “talk” with Ronald Reagan. This program would add artificial-in techniques to an updated Eliza-like program. Eliza was a program that could carry on a conversation with you, asking questions and making comments much like a psychiatrist might. In addition, Cerf asks, “What if parody, satire and good writing are added?” He calls the pre of bringing artificial intelligence to Reagan “challenging.” In time for Christmas, Cerfs team will probably The addition to the Muppet Discovery Disk will be a multipurpose program covering most of the kin- proje have more products for the Learning Ke PRODUCT de garten curriculum, according to Cerf. One part will focus on numbers, the structure of words and putting words together. Another part will involve ifying shapes and color ferences. The packz will come on two disks in the school version from Sunburst, and on three disks for the home market from Koala. Another upcoming product is The Mystery of the River of Song, the first in a series of Fraggle imilarities and dif- Rock adventures. These adventures will let you become a Fraggle, in situations where the graphics and text change dynamically: the same situation isn’t always accompanied by the same graphics. CBS will release the Fraggle adventures Looking further, you can expect to see the fruits of collaboration between Lucasfilm and Cerf in conjunction with the upcoming movie Labyrinth. Beyond that, Cerf won't say. // Michael Ciraolo is a researcher for the Boston-based Yankee Group when he’s not honing his skills as a part-time dilettante. His most serious concern is the impact of modern sctence and technology on our society, INFORMATION Muppet Learning Keys Koala Technologies, Corp. 3100 Patrick Henry Drive Santa Clara, CA 95052-8100 (408)946-4483 Kermit's Electronic StoryMaker Simon & Schuster, Inc 1230 Ave. of the Americas New York, NY 10020 (212)245-6400 OCTOBER / NOVEMBER 1985 Expandin Z-RAM for the IIc is available with 256K or 512K of additional memory and a powerful Z-80 microprocessor for running CP/M software. Z-RAM fits neatly inside the IIc. Installation is easy, clear instructions show you how. You'll need a screwdriver and about 10 minutes (if you can change a light bulb you can install Z-RAM). Z-RAM and Appleworks will knock your socks off. A 256K Z-RAM will give you a 229K av and Appleworks will be completely loaded into memory lable desktop Appleworks will now run about 10 times faster in your IIc with 1 disk drive than in other disk drives. And only Z-RAM increases the maximum llc’s with 2 number of records in the data bas processor nd lines in the word And only Z-RAM will auto segment large files so any 1 size file can be saved on regular floppies or a hard disk, A 512K Z-RAM will give you a 413K 6K Z-RAM can be upgraded to 512K by just available desktop. A 2: plugging in more memory chips Z-RAM is also a high speed solid state disk drive. With Z-RAM, your programs will load and save over 20 times faster. Z-RAM’s RAM disk is compatible with Applesoft, Pro- DOS, DOS 3.3, PASCAL and CP/M. And with Z-RAM, you can copy a disk in one pass. Just insert the original, remove the original, insert blank disk! That's it! Z-RAM is another disk drive, only 20 times faster, 4 times larger capacity, and no whirring, clicking or waiting! But before you start panting over all that don’t forget that the Z-RAM card has a buil 7-80 processor chip that allows you to run CP/M programs like Wordstar, dBASE II, Turbo PASCAL, Microsoft BASIC, FORTRAN and COBOL and over 3,000 other CP/M programs. So Z-RAM not only makes Apple programs run better and faster, it lets you run MORE programs. xtra memory, -in high speed g Your IIc With the Z-RAM card installe only now you'll have that extra memory that Appleworks and other programs need. And you can run all that great CP/M software that others can only dream about. , your IIc is still your IIc Z-RAM is 100% compatible with all IIc software and hardware including the mouse, 2nd disk, modem and printer, Z-RAM is easily handled by the IIc power supply as power consumption is kept very low by using two custom integrated circuits and a patent pending power saving design. And Z-RAM is from Applied Engineering, the ‘cessories for the acknowledged leader and innovator of a Apple. Z-RAM comes complete with manual, RAM disk soft Z-80 operating system, CP/M manual and a 5 year no hassle warranty So the next time somebody asks you why you didn’t get an IBM, tell him you bought a IIc because the IBM didn't have enough memory and was too slow and couldn't run CP/M software. And tell him you made it past the 8th grade Z-RAM with 256K Z-RAM with 512K $399 $479 If you want to run CP/M software, but don’t need more memory, may we suggest our Z-80c card. The Z-80c offers the same CP/M performance as Z-RAM but has no memory expansion ports. And the Z-80c will not affect the running of Apple programs. The Z-80c is priced at only $159.00 and should you ever want to upgrade to Z-RAM, we'll refund your full purchase price. Call (214) 241-6060 9 am. to 11 p.m. 7 days a week or Send check or money order to: Applied Engineering P. O. Box 798 Carrollton, Texas 75006 MasterCard gam Vi C.O.D. welcome. No extra charge for credit cards. Texas residents add 54% sales tax. Add $10.00 if outside U.S.A. S a and AR APPLIED ENGINEERING “We Set the Standard” PHOTOGRAPHY LORRAINE CAPPARELL COMPUTER FRONTIERS TO BOLDLY GO by JAMES CAPPARELL, PUBLISHER “Computers—the final frontier, these are the voyages. . ” An unusual introduction to a new col- umn perhaps, but as an old Star Trek fan, I remember it was an invitation like this that opened the door to “strange new worlds.” The impossible became real. I loved it. Similarly, I invite you to join me on a bold ex- pedition, one that should be every bit as exciting and challenging to your imagination. This column, to run in every issue, will take you on your own mission to the edge of computer technology, where the impossible becomes real. lintend to bring you face to face with the issues and problems of this frontier, and introduce you to the scientists and others working there. Much of what I will write about here will be commonplace within five years. You will discover philosophical implications, new vocabulary, and new professi Among these are: knowledge engineering artificial intelligence expert systems fuzzy set logic knowledge representation language translation cybernetics speech recognition robotics computer-enhanced learning The current level of software development is primitive compared to what is coming. Integrated products and fancy word processors notwithstand- ing, software has a long way to go before J will The current buzz word is “user friendly.’ I would like to replace that with “mind-amplifying” or “ability enhancing” After all, this equipment we are so pleased with should amplify our ability to perform. It should act synergistically with the motivator behind it, and that’s you. Software should adapt to your particular style of language and comprehension. A more verbal person would access the same software differently than someone visually-oriented and still feel satisfied with the outcome. The system would adapt to your skills, preferences and goals. This may sound somewhat farfetched, but I hope to show you that such programs are only a beginning. As you will see, terms like word-processing and integrated software describe very limited, unimag- inative interactions. What can be enhanced on a word-processor? Counting words and spelling them correctly? That’s not the stuff I envision. Perhaps because I've been an inveterate Science Fiction reader, I have always expected more. Can you recall the time when you could not say “xerox this?” Xerox, the company, only flourished since 1960. It quickly took its place among the For- tune 500 companies. The next “xerox” is around the corner, and it may be a typewriter that you talk at. What verb will come to mean “talk-typing” a letter? Will most of us still refer to this equip- ment as a typewriter? How about a command writer? “Here, co-write this.” If any of you come up with some good verbs, let me know. Iam sure many of you recall the famous com- puter in the movie “2001” It was the H.A.L. 9000 (Did you ever notice whose initials follow h-a-l in the alphabet?). Stanley Kubrick, the director, in- terviewed many computer specialists of the time. This was about 1966 and he embodied in H.A.L. those functions then thought attainable by the year 2001. Remember, we did not have handheld cal- culators and digital watches then. They may have underestimated the potential. The Apple most of you have on your desk is more powerful than the computer I first programmed in engineering school in 1964, and it’s 1/1000 the size. continued on page 57 James Capparell, publisher of IT Computing and Antic, the Atari Resource, formerly worked as a pro- grammer at NASA’ Ames Research Center and for Ford Aerospace OCTOBER / NOVEMBER 1985 15 TRACK HALLEY’S COMET Where to look, when to look HALLEY’S COMET 1985-1986 y now you must know— via newspapers, television and scientific journals— that Halley’s comet ap- proaches. It last appeared in 1910. In the intervening time it has fol- lowed an elongated elliptical orbit around the Sun, out beyond the or- bit of the planet Neptune, and back again to the vicinity of the Earth. We know that it has been doing this every 76 years or so since 239 BC, and possibly for the last 3000 years. This once-in-a-lifetime event has aroused great interest worldwide. But the coming apparition, unfor- tunately, will not be as spectacular as it was on some previous occasions. So this program will help you to locate the comet at any time —when you are able to see it and even when you cannot. WHAT THE PROGRAM DOES Here is a line breakdown, explain- ing the program for you. You will be prompted to enter your latitude (line 280) in degrees. Enter a positive value if you are north of the equator, or a negative value if south. Before entering your local time (300-350), adjust to normal local time if daylight saving time is in effect. The display will inform you how far the comet is from the Sun and also from the Earth (590, 820). The unit used is the astronomical unit by DONALD TATTERSFIELD (AU), or 150 million km. A display of the current coordinates of the comet will follow (subroutines 5000-5070 and 4000-4030). The former gives right ascension and declination, used by astronomers to describe the position of a heavenly body. Of more immediate use to the layman, the latter subroutine gives the altitude (angle above the horizon in degrees) and the azimuth (bear- ing measured eastwards from north in degrees). Similar information for the posi- tion of the Sun is also displayed us- ing the same subroutines. See below why we need to involve the Sun. If you then opt for a pictorial represen- tation of the position of the comet (reply Y at 1260), the vertical axis represents the altitude from your horizon (0 degrees ) to your zenith (90 degrees), and the comet is shown in the correct quadrant of the com- pass horizontally (subroutines 6000- 6210, 7000-7070, and 9000-9070). The program then gives you the op- portunity to repeat the calculation, cither for a different latitude(1310) or for a different time (1340), or both. WHAT ABOUT THE SUN THEN? The predicted brightness of Halley's comet at this appearance is about that of an average star. Although the comet will be in the sky during the daylight for some of the time, it is most unlikely that you shall see it then because it will be masked by the brightness of the Sun. The sky is dark when the Sun is more than 18 degrees below the horizon. The program will warn you (1300) if the sky is not dark at the time you have selected. Further- more, as the comet approaches the Sun, a tail will develop from the head, or coma. This might spread over an arc of tens of degrees in the sky. ‘The tail always points away from the Sun, so you need the position of the Sun to help calculate the pre- dicted direction (6000-6020) of the comet's tail. MORE ABOUT THE PROGRAM For the comet, variable AA is the semimajor axis and C is the eccen- tricity of the orbit. JD(1) is the Julian date of the time when the comet is nearest the Sun (at perihelion) — look up Julian date in an astronomy book. A(I), B(I) are also constants of Halley's orbit. For the Sun, you can find the data of 260 in the Astronomical Almanac (in this case page C24 of the 1984 edition), as well as the formulas for calculating the coor- dinates of the Sun (640-770). Your selected time is converted to Julian date (370-430). The determination of the position of the comet involves an iterative solution of Kepler's equation, for which there is no known classical solution (440-570). The remainder of the calculations needed for the position of the comet will be found continued on page 18 1 COMPUTING NaSN3F 3AVG NOLWHISNTI in (840-1070) and for the position of the Sun in (1080-1240). Finally, throughout the program there are various safeguards to put calculated angles in the correct quadrant of the circle. In particular, note that since azimuth is measured from 0 to 360 degrees of the com- pass, and you are displaying the comet in one quarter of the compass, you must bring the azimuth ZC of the comet into the range 0 degrees to 90 degrees (6080-6090). Proper scaling for the computer screen takes place in (6100-6120). The color of the d ayed comet and its tail was acceptable on my monitor, but either or both can be changed at (160) and (170) respectively. WHAT HALLEY’S COMET WILL NOT DO Halley's comet will not flash across the sky like a shooting star, nor move even at the apparent speed of an arti- ficial Earth satellite. It should be ble in binoculars by November of this year, and without any optical aid by December —before, if you have a good telescope. It will still be visi- ble in May 1986 in the southern hemisphere. You have plenty of time to see it, but do not expect to see it around February 9, 1986 —it will be behind the Sun. Donald Tattersfield, former head of the Dept. of Mechanical and Production Engincer- ing at North Gloucestershire College of Tichnology in England, is the author of Halley's Comet (Basil Blackwell Publishers), Orbits for Amateurs and other writings on astronomy and astomaulics. He is a member of the British Astronomy Association and a Fellow of the Royal Astronomy Society.// | COMPUTING ASSEMBLY LANGUAGE A CHANGE OF HEART New instructions grace the 65C02 by MORGAN P. CAFFREY The heart of any computer is its Central Pro ing Unit (CPU). Ina microcomputer this is a chip, usually referred to by its number. The revolution in personal computing was built largely on the back of a workhorse chip called the 6502, which was used in Apple II computers and in several other brands. The 6502 chip is a capable CPU, but it could be better, and now it is. Apple Computer is cur- rently installing a more powerful version, called the 65C02, in all new Apple IIc and Apple Ile com- puters. The 65C02 bestows several new options on assembly language programmers — for whom the balance of this article is written. But don't go away, beginners. Though technical, this article includes concepts and language you will confront again. OPCODE: An executable instruction for the microprocessor such as add, substract, read, store, AND, OR, shift-left, shift-right, and so on. OPERAND: The data or location being acted on by the opcode. An immediate value, the content of a location. MODE: A method of using an opcode that differentiates between accessing the operand from an absolute location, froma location pointed to by another location, and so on. Modes provide flexibility to the microprocessor, and it is usually nicer to have a smaller number of opcodes with a variety of modes than a large number of dif- ferent opcodes. ‘The 65C02 is a pin-compatible replacement for the 6502 in all Apple II-type computers. It is part of the “enhancement” upgrade for older Ile’s. It offers lower power consumption and some deft ex- tensions to the parent processor's instruction set. The advantages are very real. The improvements consist of 27 new opcodes made up of ten new instructions and two new ad- dressing modes. (See box for explanation of terms.) Some things ha “ome much simpler, some faster; some more elegant, requiring code. Let's look first at those instructions that are essen- tially extensions of existing instructions, but with different or augmented modes. SIMPLIFIED BRANCHING Was I waiting for this one? You bet! A Branch Always (BRA) instruction. It has no flags to con- trol or predict or manipulate, no faked comparison; you need only branch relative to the present pc tion +127 or -128. It does not change th any processor flag. This change adds simplicity and legibility, but I still wish for a signed, 16-bit branch for additional ease in writing relocatable code. INCREMENT AND DECREMENT ACCUMULATOR I sometimes need to add one or subtract one from the accumulator. Compare the sad methods I have used to the new, simpler version. Table 1 6502 ADDITION SUBTRACTION TAX | STAZPDEST | TAX | STA ZPDEST INX | INC ZPDEST | DEX | DECZPDEST TXA_| LDA ZPDEST | TXA__| LDAZPDEST 65C02 ADD OR SUB INA] DEA It is nice to substitute one instruction for three, even if I don’t use the instruction often. continued on next page te of Morgan P. Caffiey is a programmer/ analyst concentrating on expert systems, databases and tele- communications. soft- war. He was an carly Apple IT owner and former technical editor for Apple Orchard magazine, OCTOBER / NOVEMBER 1985 ASSEMBLY LANGUAGE PUSHING THINGS AROUND Similarly, there are new push instructions. Now, stacks are nice. I like stacks. The stack keeps track of subroutine calls and saves register values that must be restored. The 6502 offers a quick stack (you need to look at other processors to appreciate the speed), but restricts the programmer to 255 bytes. Let’s look at the old and new methods to save the processor status and ail the registers. Table 2 6502 65C02 PHP PHP PHA PHA TXA PHX ; new PHA PHY ; new TYA JSR DOSOMETHING PHA PLY ; new JSR DOSOMETHING PLX ; new PLA PLA TAY PLP PLA - TAX = PLA - PEP - 13 Instructions versus 9 This difference might seem trivial, but if you examine code that extensively uses registers, you'll see this is frequently done. The old processor’s need te channel registers through the A-register is time- consuming and not elegant. The newer method is better. ZERO Zero is so useful. It clears the high-resolution screen to black. It sets my numeric arrays to naught. The 65C02 offers the following simple saving and doesn't bother a single flag: Table 3 6502 65C02 PHA = LDA #0 STZ DEST ; store a zero STA DEST - PLA - 4 Instructions versus 1 In both cases the contents of the A, X and Y registers are the same after as before the opera- tion. This is not always necessary, but frequently it is. The new instruction supports ABS, ZPG, ABS,X and ZPG,X modes. ABSOLUTE INDIRECT ADDRESSING A sweet feature of the 6502 is the indirect address- ing. If you use the Y-register with a single byte loca- tion in the zero page, you can reference any loca- tion in memory. It’s great for accessing and main- taining tables and also for various memory moves. Viewed this way, the 6502 has 128 16-bit memory pointers, any of which you can access with a sim- ple two-byte instruction. The trouble is always that you have had to use the Y-register, which at times is awkward. Fre- quently it is easier and defter to leave Y=0 and manipulate the zero-page pointer directly. The 65C02 has absolute indirect addressing: for example, LDA (ZPG). You don't have to be con- cerned with the Y-register. A single two-byte in- struction can now load, store, add, subtract, com- pare, AND, OR, and EOR anywhere in memory. EXTENDING THE USE OF TABLES The following instructions make a widened use of tables: TABLEBASE EQU « ; symbolic pointer to base of table of routines DA NATIONALDEBT DA BASEBALLAVERAGE DA SUBTRACTION DA DIVISION ~ DA INSERT DA LOWERCASE The construction above creates a table of two- byte execution addresses. You can do something similar with most assemblers; that is, if the pro- gram executes at the location pointed to by any table entry, the described function is performed. The 6502 provides a slightly awkward method to jump to any one of these addresses, but the 65C02 more elegantly indexes the Jump Indirect by X. The problem with the 6502 Jump Indirect is that if, by chance, the assembler that stores the code locates the table entry such that the two-byte value crosses a page boundary (bytes 0, 256, 512, and so on, throughout memory), the low byte would be taken properly but the next byte would be taken from 256 bytes lower. You would execute code at the wrong address. A sharp programmer learns to watch for and avoid these problems. A better processor avoids the problem, and the 65C02 fixes it at the cost of just one cycle—a good trade. 20 1 COMPUTING ASSEMBLY LANGUAGE TABLE JUMPS When preparing the equivalent of a CASE state- ment in assembler, the 6502 has a slightly split per- sonality: nice architecture, but awkward in use. The user presses a key and the code “vectors” to the right routine for the key pressed. In the 65C02, utility is about the same but the routine is simpler. TABLE 4 A = 0,1,2,3,4 ... 127—returned from keyboard 6502 ASLA ; mult by 2 TAX ; make index LDA TABLEBASE,X STA LOC INX LDA TABLEBASE,x ; STA LOC+1 ; high byte JMP (LOC) ; jump indirect 65C02 ASL A TAX JMP (TABLEBASE, X) 8 Instructions versus 3 This new construction saves both space and time. READ/WRITE INSTRUCTIONS Some of the instructions indexed by X that do both a read and a write in a single instruction have been speeded up. ASL LOC,X~—arithmetically shift left the byte LSR LOC,X~—arithmetically shift right the byte INC LOC,X—read, increment, store DEC LOC,X—read, decrement, store These can be used for bit manipulation and for multiplication and division. A savings of one cy- cle may not seem like much, but if the cycle is repeatedly saved all day long, or at a critical junc- ture, the savings become noticeable. (In process- ing every bit on a high-resolution screen — 57,344 bits—you generate some time savings if the im- age changes frequently.) BIT FLIPPERS’ DELIGHT Bit manipulation can seem like Greek even to seasoned assembly language programmers. The idea is to isolate and process a bit (in a number, on the graphic screen, in a controller device). Once again the 6502 seems a little too hard to use, although programmers have coped with and even triumphed over it in various machines. There have been a couple of changes in the bit manipulation capabilities. [ll start with the bad news, which isn’t very bad. A good method for testing individual bits in a memory location, the BIT instruction has lost one rarely used ability. If you perform the BIT instruc- tion in the immediate mode (the same result each time the code is executed), the 6th and 7th bit are not reflected in the processor status flag. If the im- mediate operand is a zero, the Z-flag is set, so the instruction may still be useful. In the 6502 the bit is frequently tested by shift- ing the byte left or right until a processor status flag is altered, then you branch appropriately. The 65C02 design simplifies this read-manipulate-store sequence. The TRB (Test and Reset Bit) does an AND with the present contents of the A-register (usual- ly the “mask”), sets the new value of the bit(s), and automatically stores the results back. TSB (‘Test and Set Bit) does an OR of the A- register and the memory location contents and stores the results back. The only processor flag affected is the zero-flag. ‘The addressing modes are somewhat limited; only absolute and zero-page is provided (no indexing). CONCLUSION Notwithstanding all the wonderful upgrades, the 65C02 could be improved even more. I would like a real 16-bit register. When I increment a zero- page location, I want an increment instruction that can detect a carry and automatically increment the next sequential location. I also want the same thing in reverse for the decrement. I don’t suppose I'll get them soon, but there’s no harm in mentioning it. Finally, the new chip has a few drawbacks. If you use this nice extended set of instructions, the software written won't be compatible with a lot of the existing earlier Apple IT computers, unless the owners individually decide to upgrade. This makes commercial application of the processor's features somewhat more complicated. Also, the exisitng monitor in ROM does not disassemble the new mnemonics, nor can the old mini-assembler in ROM assemble the new instructions. Most of the existing assemblers won't be able to compile the new instructions. I’m sure most assembler manufacturers will upgrade, and some have already. These include Merlin PRO from Roger Wagner Publishing, Lisa 2.6X from Lazer- ware, and Big MACC from Call A.P.P.L.E. // OCTOBER / NOVEMBER 1985 a APPLEWORKS ENHANCEMENTS Read why Applied Engineering is the acknowledged leader in AppleWorks enhancements @ Applied Engineering was first to expand Appleworks beyond 55K. ™@ Applied Engineering was first to eliminate disk access on Drive 1 in Appleworks, thereby dramatically speeding up the program and reducing disk drive wear. @ Applied Engineering was first to expand AppleWorks to 1 megabyte of memory. @ Applied Engineering was first to expand AppleWorks to 2.5 megabytes. ™@ Applied Engineering was first to provide auto segmenting on large files so any size file can be saved on regular floppies. @ Applied Engineering was first to increase the maximum number of records in the data base from 1350 to 5100. ™@ Applied Engineering was first to increase the number of lines in the AppleWorks word processor from 2250 to 5100. @ Applied Engineering was first to display the time and date on the AppleWorks screen. @ Applied Engineering was first to provide auto dating as part of the data base field. @ Applied Engineering was first to provide auto time stamping as part of the data base field. @ Applied Engineering was first to give push- button telecommunication power to AppleWorks by merging the word processor to M.C.I. mail. With all of these firsts, it's no wonder most people choose Applied Engineering when they want enhancements to Appleworks. Especially when you consider that nearly all the “firs ” listed above are “onlys” too. And our Appleworks enhancements are as easy to use as inserting a disk and pressing return because all enhancements are merged with the AppleWorks program disk and stay there out of sight until needed, only now AppleWorks will run up to 20 times faster, and be easier to use at the same time. And we're working on new improvements to AppleWorks all the time, so the few remaining criticisms the software reviewers gave AppleWorks will vanish forever. So if you want more out of AppleWorks, order RamWorks and Timemaster H.O. for the Ie or Z-RAM and IIc System Clock for the IIc. You'll find specifi- cations and prices for these products listed in this magazine. Please look for Applied Engineering in the advertiser's index. There’s no question about how they'll increase your productivity. The only question you'll have is how you ever got along without them. 214-241-6060 A APPLIED ENGINEERING “We Set the Standard” ECTO BLASTER Works with DOS 3.3 and ProDOS. by STEPHAN SCHWIRZKE The house is dark, and worse, it’s haunted! Ghosts appear out of nowhere and rush about trying to drive you away. You have been called in to rid the house of these ectoplasmic interlopers, which you can only do by de-energizing them as they come towards you. You are armed with the latest anti-ghost weapon. Its laser-driven sight projects a “prohibited” sign wherever the joystick directs. When you press the joystick button, a gout of entropy juice squirts out from your position at the bottom of the screen towards the place marked by your sight. If the juice hits a ghost, the ghost shrivels and disappears. Every time you successfully blast a ghost, a can- dle lights on the chandelier so you can see a bit more of the room you are in. When all ten candles are lit, you win the game. But every time a ghost gets past you, a skull is added at the bottom of the screen. Collect ten skulls and you lose. Those of you without a joystick can play from the keyboard by using the alternative lines 320-400 (see listing), and by changing line 4050 to read GET A$: GOTO 60. Keys I, J, K and M control direction of your sight, and the space bar substitutes for the trigger button. There is no TYPO II table for the keyboard alternative. To use TYPO II, enter the entire program for joystick, verify its accuracy, then carefully replace the joystick lines with the keyboard lines. Some Important Variables: S= number of current shape being drawn A(S)=0 shape not being drawn A(S)=1 shape being drawn X= horizontal position of sight y- vertical position of sight S4- speed adjustment in line 5005 to increase difficulty G(S)= horizontal position of ghost U(S)= vertical position of ghost JS)= scale of ghost U(S)= speed of ghost Q(S)= previous scale of ghost (used to erase) Explanation of Program Lines: 80 draws bullet and explosion 90-140 checks for hit 150-170 adjusts difficulty (speed, rate of scaling) 180-200 lights candle 210-270 explodes ghost 280-300 clears room to brightest color, gets rid of any leftover ghost 320-410 reads joystick (or keyboard) 430 erases and draws laser sight 440-550 erases and draws ghosts, adjusts scale, moves ghost left or right, determines if ghost has escaped 1000-1050 resets variables for new ghost 2000-2190 resets variables to draw room 3000-3040 sets up collision values 3050-3100 values used to check for colli- sions, plot room colors, and POKE machine language sound routine 3110-3140 shape tables 4000-4040 = “you lose” message 4050-4060 = awaits button press for new game Ua Listing on page 62 Stephan Schwirzke ts a college student studying computer science. Hes currently writing an arcade game in assembly language. hitiwese™ B. BENJAMIN OCTOBER / NOVEMBER 1985 23 Neil Shapiro is editor-in-chief of MacUser Maga- zine and is also chief sysop of the MAUG Apple Group on CompuServe. FOR THE FUN OF IT OF JEWELS AND GHOULS AND BUTTERFLIES AND STRATEGIES OF WAR by NEIL SHAPIRO The world of gaming on the Apple II is as varied as the people who own the machine. Creating soft- ware ranging from dazzling graphics and anima- tion to complex brain-wrenching games of strategy and tactics, programmers on the Apple II are con- stantly striving to achieve new goals and more ex- citing products. Here are some games that demonstrate this wonderful ability of the Apple IT to amaze and entertain anew. CHAOS AND ORDER RETURN Archon II: Adept from Electronic Arts is a follow- up to its game Archon. That first game was played on a chessboard-like field with pieces moved by joystick. When one piece attempted to take another, the two pieces would engage in fast, arcade-like action to contest ownership of the square. Archon quickly became a classic, with its ingenious com- bination of chesslike strategy and arcade tactics. Well, Adept is even more challenging than its predecessor, and features exciting innovations. In Adept, the Master of Order must struggle against the Mistress of Chaos on a battlefield of the four elements of Earth, Water, Air and Fire. The battlefield screen is a bright, almost dazzling display of the four elements arranged in concen- tric rectangles. The bright-red outer area represents (of course) Fire and features animated flames. In the inner Water area, waves move. Juxtaposed with the rocky green Earth and the calm violet Air, the animated elements make the battlefield screen a visual feas The players each control the Adepts of Order or the Adepts of Chaos. One of the players may be the computer opponent, as the computer can play either side. Two people may play each other, but that requires either the special equipment needed to hook two joysticks to an Apple or keyboard control by one of the players. Unfor- tunately, the quick action in the game makes the keyboard fairly impossible to use. So figure that most of your play will be against the computer, but that’s okay because the computer plays a most respectable game. Each Adept shown on the screen may cast spells, summon an army of demons and monsters, or simply move and fight. The object is to capture six flashing power points that, from turn to turn, move about the outermost corners of each of the four elements. An Adept who casts a spell may summon one of eight varieties of demons or monsters, may heal an ally or weaken an enemy, release an ally or im- prison an enemy, or (not very often) banish one enemy from the board. An aptly named Apoca- lypse spell decides everything in one immense battle. In most moves, the Adepts summon the crea- tures of Order or Chaos to serve them in subse- quent turns. The creatures all have different modes of fighting and different amounts of life force (stay- ing power), depending on which element they are fighting in. The Firebird, for example, can take more blows before dying if it fights in the domain of Fire than in Water. When one creature or Adept challenges another, the battlefield screen clears to a tactical display. This tactical display may feature various obstacles or ter- rain, depending on the element field. But th tion can be fast and furious, as the fighters are con- trolled by joystick. Some fighters, such as Giants, throw rocks; others, such as Sirens, have more in- novative ways of close-in fighting. Learning how the various occult soldiers fight is one of the game's most attractive features. It’s good to see a sequel to a successful game that is not only as good as the first but extends the boundaries of that game's system. Adept is such a success. 24 I COMPUTING GF JEWELS, BUTTERFLIES AND AMOEBAS Finding a new idea in arcade games that is both different and playable is like finding a jewel in the rough. And no one knows more about finding jewels than Rockford, the personably animated main character of Boulder Dash from MicroFun, a rock-and-rolling excursion into fantasy and tac- tically governed reflexes. Featuring 16 caves, this game can satisfy the most jaded arcader. At first glance it s the Dig-Dug school of games: little guy who tunnels about underground. As he tunnels, he can undermine various boulders, caus- ing them to fall through tunnels already dug and crush his enemies —or himself. But whereas Dig- Dug depends on a shoot-em-up philosophy (or at least blow them up), Boulder Dash demands that you think almost as fast as you can scream, madly yanking the joystick back and forth. You see, scattered about in the caves are both jewels to grab and strange enemies that you must overcome. For example, the amoeba, a green amor- phous blob, inexorably advances on Rockford from behind and begins to fill the tunnels as Rockford digs them. But wait, the deadly butterflies hover and glide about in the dangerous caverns— and their very touch is death to Rockford. But if you drop boulders just right, you can guide the but- terflies to impact the sides of the growing amoeba. When that happens, a quick flash lights the screen as the butterfly explodes from its brief amoeba con- tact and turns into a scintillating jewel for Rockford to try to pocket. Bright, colorful animation coupled with a breezy story line make this game more than just a momen- tary diversion TWO GAMES: TWO THEATRES Simulation gaming used to require a person who wasn't afraid to learn a lot of complex rules and do hundreds of calculations, could find up to twenty square feet of floor on which to pla: juggle thousands of tiny cardboard pie knew at least one other person who shared all these traits and skills. That is no longer true. The Apple II can bring complex, historical simulations to its screen in a way that makes such simulation games easier than ever to learn and play. Although these simulations do require thought and concentration, they bring a feeling of reality and veracity to gaming. Carriers At War from Strategic Studies Group (SSG) and Kampfgruppe from Strategic Simula- tions Inc. (SSI) both simulate various World War FOR THE FUN OF IT II actions at a tactical level. Rather than the bold, strategic action of moving entire armies and divi- sions, these games simulate the multitude of smaller events and movements that make up a battle. Carriers At War magnificently simulates the war in the Pacific fought by naval fleets. But even though the rules are com- plex and tightly in- terwoven, it uses command menus that make it easy to enter into play and to keep track of hun- dreds of different items. The display from menus to a strategic map that shows the Pacific islands and the fleets present. You may overlay the map with a weather map, which also indicates the wind or storm velocity. Furthermore, you may zoom in for a closer look at any part of the strategic map. You can keep track of every plane aboard every aircraft carrier — individually — as well as each plane and ship present at various bases. The amount of detail would be truly staggering but for the text screens of multiple-choice menus that quickly become second nature to you. By using these s, you can arm aircraft and send them out ir missions. You can also control the move- on thi ment and the mis: sion ability of every ship in all the fleets you command. Many details are taken into account —how long it will take the planes to clear the runways, how long it takes to arm them, the dis- tance to the target, and so on. And be- cause the computer is doing the calculations, you need only sit back and see how your decisions have turned out. Once you have played the six scenarios cover- ing Pearl Harbor, Coral Sea, Midway, Eastern Solomons, Santa Cruz, and Philippine Sea (and you may take any side in each action, or even play opposing subsidiary commands!), you can design your own dramas. Using keyboard control to move n cursor, you can first design a map an on- PAUSE ON BOULDER DASH STRIKE ORDER CARRIERS AT WAR continued on next page OCTOBER / NOVEMBER 1985 25 KAMPFGRUPPE iON DD cuinera coBHONS" ARCHON II: ADEPT FOR THE FUN OF IT of water, islands, airports, and bases. Although a joystick might have been more useful here, you can draw maps quickly once you have the hang of it. Then you can design the individual characteristics of planes, ships, and carriers, and even program the weather. It's no wonder that the Design Manual that comes with the game has 24 pages and the Player's Manual only 16. Besides its histori- cal accuracy, Car- riers At War is the best-playing simula- tion of naval warfare I have seen on either tabletop or video monitor. Kampfgruppe from SSI recreates the fire and move- ment of the bitterly contested Eastern Front campaigns. For two-player action, each player may take the Russian or German side; solitaire play is also allowed, as the computer can take either side. Of all the computer simulation games on the market, Kampfgruppe gives the most realistic feel of tactic mored combat. Although played on the video game brings to mind tabletop armies of small lead models of tanks and men favored by many so-called miniaturist war gamers as well as by the more serious folk in the Pentagon. On the battlefields of Bryansk, Stalingrad, Kiev, and Berlin (as well as random terrain), the Ger- man and Soviet commanders in the game have to face many of the same strategic decisions made historically as well as taking a hand in the minute- by-minute tactical maneuvering of tanks, artillery, armored guns and infantry. Each grouping of units i ANEPT shown on the screen silhouette. direction a tank is facing, and the ter- But rain. what makes this game innovative is that it implements sight or LOS rules. In noncomputerized gaming, line-of-sight rules often add realism at the expense of playability. | Many tabletop players rue the day they started a game that required long rulers, protractors, pieces of string, and the patience of Job. But add an Apple computer to such a brew and the LOS rules come alive. In Kampfgruppe, all you have to do is to move the cursor atop a unit, press V for view and— presto! — the territory that the unit can see and fire into lights up. There’s no longer any doubt as to whether you can spot a particular unit or if the corner of a wooded area blocks your view. Kampfgruppe is not an easy game, but this new method of showing LOS calculations makes it attractive to the computer war gamer. // PRODUCT INFORMATION ARCHON II; ADEPT Electronic Arts 2755 Campus Dr. San Mateo, CA 94403 (415)571-7171 Requires 64K; $39.95. BOULDER DASH MicroLab, Inc. 2699 Skokie Valley Rd. Highland Park, IL 60035, (312)433-7550 Requires 48K; $40.00. CARRIERS AT WAR Strategic Studies Group TTY. Ltd. 336 Pitt St. Sydney, Australia 2000 Requires 64K; $59.95. KAMPFGRUPPE Strategic Simulations, Inc. 883 Stierlin Rd. Building A-200 Mountain View, CA 94043 800-772-3545 X335 Requires 48K; $59.95. ACTION DISK OWNERS! See page 77 for instructions on DOS 3.3 conversion, if necessary. 26 I COMPUTING TALES FROM THE CRYPT CRACKING CIPHERS WITH YOUR COMPUTER An Introduction by CAXTON C. FOSTER Cryptography is the science of writing messages that no one but the intended receiver can read. Cryptanalysis is the science of reading them anyway. Both sciences date back to antiquity. One of the earliest ciphers, known to the Greeks, is called the skytale (Figure 1). Creencaemerenten ig Figure 1 ‘The sender took a straight rod, and around this he wrapped a long, narrow strip of parchment, spiral fashion, with the edges of the spiral touching. Then he wrote his message on the parchment along the length of the rod, with successive lines around the rod (like on a typewriter platen.) The parch- ment, when removed from the rod, read like gib- berish. It was sent to the recipient whose duplicate rod served to recover the message. Politics and romance have generated the long history of secret writing, and indeed, much of the best work in cryptology was done before the com- puter was invented. However, because the com- puter is so good at detailed routine work, it makes a perfect tool for those of us devoted to reading ciphered messages The computer can’t do all the work, of course. You have to program it to do your dogwork while you use your trained intuition. Training your in- tuition will be the purpose of this column, both in terms of cryptology and of applying your com- puter to the problems that arise. Il supply sam- ple crypts and programs as we go along. Solutions will appear in following i: As you become proficient, our problems will get harder, and eventually we may jointly put our minds to solving the most difficult codes that exist today. They say it can't be done, but never underestimate curious minds served by a computer! I will assume you do know the fundamentals of BASIC and have some kind of Apple II com- puter system. A printer is very helpful, but not necessary. I won't assume you know anything about cryptanalysis, so we'll have to spend some time learning fundamentals. In the “big picture” (Figure 2), Alphy wants to send a me > to Betty so that Charlie can’t read it, even if he can intercept it. sues. PLAINTEXT CIPHERTEXT PLAINTEXT. A ENCODER t DECODER B 1 | eee t J ~interceprion CRYPT. ANALYSIS. oes PLAINTEXT c Figure 2 Alphy composes the message in plaintext, a language he and Betty know, which we will assume is English. Alphy puts the message through a pro- cess known as encipherment. The result, ciphertext, is sent to Betty. Betty then puts the ciphertext through decipherment and recovers the plaintext. Meanwhile, Charlie intercepts the ciphertext. He can't read it unless he can solve the cipher. This process is called cryptanalysis. continued on next page Caxton C. Foster, a Ph.D. in Electrical Engineering, was a Computer Science professor at Univer- sity of Massachusetts. Presently he ts a consultant to Mount Castor Industries of E. Orleans, MA, which designs com- puter programs for school administrative use, Dr. Foster is the author of five books and numerous technical articles. OCTOBER / NOVEMBER 1985 27 TALES FROM THE CRYPT Even if Charlie can solve the cipher, he must do it in time to use the information. With enough time virtually any cipher can be broken, provided there is enough ciphertext to work on. But consider Paul Revere’s code. We all know what two lights in the steeple meant, but the British could never have figured it out because of lack of data. Notice I called Revere's lights a code. A code deals with symbolic substitution of whole words or phrases, whereas a cipher deals with individual let- ters. In the computer world, one meets codes in the guise of passwords, for example, those used to log onto CompuServe. A computer could con- ceivably discover a password by trial and error if the host system did not reject repeated attempts, but usually breaking codes requires much more memory than your Apple II provides. Therefore, we will stick to ciphers. ‘These come in two kinds: transposition ciphers and substitution ciphers. In a transposition cipher the plaintext stands for itself but the letters are arranged in an unusual order. In a substitution cipher, other letters stand for the plaintext letters. Here are two examples. Suppose you found a strip of paper with the following series of letters: PSLCLEEEPNEE- SNHAOADT. It’s obviously ciphertext of some kind. You may want to wrestle with it a bit before looking at the solution below. Ciphertext: PSLCLEEEPNEESNHAOADT Figure 3 When you do solve it, you will notice that the solution depends on the physical placement of the letters, and not on the substitution of the letter by other letters or symbols. This is the railfence cipher, a simple form of transposition cipher. The letters stand for them- selves, but the plaintext message is written in a series of V's, while the ciphertext reads in a single horizon- tal row. We will devote considerable attention to transpositional ciphers. Here is an example of a substitution cipher: KDYLQJ D ZRQGHUIXO WLPH. Can you discover its meaning, knowing that in this case let- ters have been systematically substituted for other letters? The single D is a big clue. This is known as a Caesar cipher because it is of a kind used by Julius himself. Actually, a BASIC program could test for the premise of this substitution, but it’s easy enough without a computer. Give up? Each plaintext letter has been replaced by the letter that occurs three positions later in the alphabet. The single D is a clue because the 2 cle “a” is one of the few one-letter words in English. The peculiarities of the plaintext are very impor- tant in solving substitution ciphers. Substitution ciphers can get very complex. In addition to letter-for-letter substitution, there is a polyalphabetic substitution in which several substitu- tion alphabets are used in rotation (or otherwise), and polygraphic substitution where two or more plaintext letters form the unit for encipherment. The U.S. National Bureau of Standards’ “Data En- cryption Standard” consists of 16 stages of substitu- tion, each followed by a transposition. Almost a century ago, Auguste Kerchoffs laid down six general rules for military cryptography which still hold true today: ii 1. The system should be unbreakable in practice, if not in theory. 2. Assume the enemy knows the system except for the key being used. 3. The key should be easily remembered. 4. Ciphertext must be transmittable by telegraph or teletype. 5. Apparatus must be portable and operable by one person. 6. The system must be easy and uncomplicated. Several of these rules have implications for our work, for example, “transmittable by teletype” im- plies use of letters and symbols belonging to the character set of our computers. But an important additional concept here is the notion of key. The key to a cryptic system is a piece of infor- mation that determines how the system will work in a specific instance. Knowledge of the system is (almost) useless without it, and the key can be changed as often as needed, even at the moment, as long as both sender and receiver have it. Often the key is a single word (easy to remember) whose inherent characteris determine procedure. Consider the following ciphertext: LMVSL SNSNA AIA EI PLI TOPS B LS D OB UUAs UR YS Suppose you know we are using a transposition system in which the plaintext is written out horizon- 28 I COMPUTING TALES FROM THE CRYPT tally in rows of six letters each, and that each col- umn formed by this proc is “read” into the ciphertext format (horizontal groups of five letters) one column at a time. The order of the columns, first to last, is determined by a six-letter key word. A key word can dictate procedure in many ways, but a common way is by the precedence of the various letters in the alphabet. If the key word were HAYDEN, the first column of plaintext to be read out would be the second, or “A’ column, next would come the fourth, or “D” column. The third col- umn to be taken would be the fifth, or “E” column of plaintext, etc. The last column would be the third, or “Y” column. Ofcourse, HAYDEN is not the key word in this cryptogram. But knowing this much, you can solve this cipher by hand, or with a computer program, even if you don’t know the key word. ‘To make it interesting I challenge you all to come up with a BASIC program to mplish this solu- tion. The winners (in our subjective judgment) will receive an appropriate reward yet to be determined (at least their name in print). The key word and how it works will be described in the next install- ment of “Tales from the Crypt.” Send your program to: CRYPT #1, Antic | Publishing, Inc. 524 second St., San Francisco, CA 94107. // Start An Apple Computer Club! If you’re a teacher, community activist, interested parent — you can start an Apple Computer Club. Apple Computer, Inc. organized the Apple Computer Clubs International in 1983; now there are over 15,000 clubs worldwide. You don’t need to be a computer expert to run a club; you just need a sincere interest in com- puters and the role they play in the lives of young people. The Clubs are committed to “improving educational computing by encour- aging the positive use of microcomputers by youth.” Mini and major competitions are held to encourage excellence. Prizes often include trips and computers. An advisor receives Computer Club News, the advisor newsletter, and The Apple Computer Club's International Handbook which provides background and ideas. Register before November 1, 1985 and you'll receive a year of Club benefits for only $10 (half _,_ the regular $20 registration fee) and two blank disks. For more information, contact: APPLE COMPUTER CLUBS INTERNATIONAL Box 948 217 Jackson St. Lowell, MA 01852 (800) 343-1425 OCTOBER / NOVEMBER 1985 29 POWER PROGRAMMING HI-RES LABELER Small caps character set for HGR by WM. V.R. SMITH and STEVE KOEPKE Bill Smith is presi- dent of Artsci, a software company specializing in business products for the Apple IZ, and a former participant in Softalk where this program first appeared. It has been enhanced by Steve Koepke s graphics is one of the mos of the Apple IT computers. Here gram that puts small cap text at your disposal for labeling hi-res screens. Several commercial products now facilitate draw- ing or “painting” in hi-res, and a few give custom character to superimpose on pictures (S NOTES.) The machine language character gen- erators in some of these programs are so sophisti- cated that the simulated text acts exactly as you would expect real text to behave. This program is not as fast or fancy as com- but it works, and it shows you one way to accomplish this task. You will be able to load and save hi-res pictures, write labels using capital letters, numbers and red symbols, posi- tion them on the screen, put optional borders around them, and put optional pointers from them to any area on the screen. Once you understand the program, you may be able to design different custom characters of your own. mercial ones The characters generated by this program are limited to 70 per line. This is because the hi-res screen can display a maximum of 280 pixels (points of light) from left to right. Divide 280 by 70 and you get a width of four pixels per character, Each character needs at least one pixel for horizontal separation, | pi wing an absolute minimum of three to define the character. Note that these characters are reGuite small. They look best on a monochrome monitor or printout. On a color monitor some letters lose definition due to artifacting (unintentional color resulting from the pe on the ion of the pixels relative to the phosphors n). The routine i efficient and adaptable to your own programs. The section at the end, beginning with line 1060, is the first part that runs. It sets up an array, B$(X), and stores the data for creating the characters. Then it builds two shapes: cross hairs for positioning the pointers and brackets for posi- tioning your labels. We put these functions at the end because they are used only once. Data in lines 1150-1230 defines 61 characters from ! through ] (ASCII 33-93). Each is three pixels wide and five pixels tall. Another way to say this is that each character is composed of five rows of three pixels each. Each pixel is either on or off, lit or dark, so there are only eight possible combinations for any row. Let’s represent this in standard binary form as shown below. A dot means the pixel is off, an asterisk means it is on. =n0 wom] * s2 ee = 3 * 4 or) ** 6 sa eee ibilities can be stacked in five rows to create the shape of a character, for example, the letter A. 22 * eo se 7 * ea 5 * gor} Each row of three pixels can be thought of as a binary number for which the decimal equivalent, 30 I COMPUTING POWER PROGRAMMING a single digit, is shown to its right. String the decimal equivalents of the rows together to create a code from which the program can reconstruct the character. For example, 25755 represents the letter A. All the five-digit numbers in the DATA state- ments were determined this way. Each represents -odes, but there are heme — size of character, for the characters by changing th limitations to this example. The program works in stages. We'll break the program down into component parts and describe them sequentially. The first chore is to set up variables and data tables, so line 70 jumps to to the end of the program to do this. Then lines 80—140 establish overall functional structure. Lines 160 through 290 load or save a hi-res picture for you to label. Lines 300—340 accept your input from the keyboard and put it in ANSR$. Notice GET is used instead of INPUT becauseApplesoft BASIC will not accept the comma and colon characters as input. The label can be up to 70 characters long (one line). There is no limit to the number of labels per picture. Lines 350—480 position the label. Use the four keys I, J, K, M as up, left, right, and down, respec- tively to move the positioning brackets around the screen. Lines 490 —520 darken the area where the label goes. This makes the characters more visible. At line 530 the program begins to plot the in- dividual characters of the label. It takes the string in ANSR$ and breaks it into individual characters. The program then translates each character into an ASCII code (See box, page xx), and puts the value into the variable C. one character. You can change the appearance of Then the program looks up the character in the array B$(x) and determines from the code how each of the five rows should look. It puts the number code for each row into variable PL and plots it on the screen in lines 840 —920. Option for the border is in lines 610 — 640; op- tion for the pointer begins at 650 CHALLENGE: Can you redesign the characters in lower case? CHALLENGE II: Can you make the character set taller and wider? ASCII Values for this Program 33 =! 48=0 6=@ 79=0 34 = ¢ 49=1 65=A 80=P 3=# 50=2 6=B 81=Q 36=$ S51=3 67=C 82=R 7=% 5254 6=D 8=5 B=6 58=5 6G=E 84=T 39.=.' 54= 6 ‘OS F 85=.U 40 = ( S5=7 71=G 8=V 41 =) 56'S 8s. “72 =H. Bea Ww 42=* 57 = 9) 73= 1 88 = X 48=+ 58 =. | BS y 44=, 59 W=K 90 =Z 45 =- 60 Tesi 91S 46=. 61 Tf SIM, 92k \ 47 =/ 62 = (8s) N)1: 93'S) ) = 63 = = = NOTES: Some commercial hi-res drawing programs: Fontrix (Data Transformers); Apple Mechanic (Beagle Bros.); Flex Text (Beagle Bros.) // Listing on page 65 NO MORE TYPING!! It’s true when you subscribe to Il Computing’s ACTION EDITION! Every issue will contain programs for Education, Adventure, Utilities, Business and more. Instead of keyboard frustrations and program debugging, all you have to do is Load and Go! Find out more details in the easy-order Subscription forms in this issue. OCTOBER / NOVEMBER 1985 a 32 SPREADSHEET HORRORS And how to avoid them... by ROBERT M. FREEMAN Pe CN preadsheet horror stories. No for Multiplan is kludged to a mutant surge suppressor. Spreadsheet horror stories are the recent revelations showing the risks and hazards of careless spreadsheet use. Thousands of would-be analysts are setting up computerized spread- sheets to assist them in business or personal decision making. They ex- pect the computer to chew up their data and spit out the right answers. So confident are they that they often don't recognize wrong answers when they them. If a person uses a calculator, for instance, to compensate for weak math skills, chances are this person’s math conceptual skills are weak as well. When this conceptual weakness is applied to spreadsheet design, you can imagine what the potential for error might be. Don Valentine, a venture capitalist quoted in Jnc. magazine, said of some entrepreneurs who didn’t make it: “Their thinking is hindered by their reliance upon computers. Since the advent of elec- tronic spreadsheets, projections are no longer written out by hand and really thought about, with the result that many people have no personal understanding of the numbers they're projectin; The Wall Street Journal recently reported an acquisition blunder that cost a Texas oil and gas company millions of dollars—and several ex- ecutives their jobs. The error was 1 COMPUTING ILLUSTRATION PAUL OLLSWANG ii he traced to a faulty financial analysis done with a personal computer spreadsheet model. A marketing manager at a Silicon Valley computer firm, Business Week reported, made an eight-million- dollar mistake on for s for anew line of computers. The manager used the wrong formula for a price discount on components which re- sulted in underestimating co: In Chicago a novice real estate in- vestor used a spreadsheet program template to forecast expenses and OCTOBER / NOVEMBER 1985 Met tii returns on a small office building. Encouraged by the analysis, he bought it. But while the building was an open architecture design, the template formulas for allocating pace reflected traditional closed-office design. As a It, the investor seriously overestimated potential revenue growth and suf- fered a much lower than he had ex e of return d. > using spread- than ever before; more business and personal applications are being programmed using spreadsheets. In addition to the above examples, typical applications inventory man- agement, sales forecasting, budget- ing and a host of others. Experienced spreadsheet users will understand how blunders occur. Most, in fas own horror stories. And, what they include accounting could recount their might agree upon is that cer common problems relate to the very essence of spreadsheet functions continued on next page 33 34 WHAT SPREADSHEETS DO Let’s look briefly at an example of how spreadsheets work and where problems can arise. Then welll ex- plore ways to prevent spreadsheet disasters from happening to you. First, we need an explanation. Personal computer spreadsheets define and preserve numeric élations between measurable entities. This idea of relations is important because a spreadsheet allows users to play with many different combinations of numbers without affecting the rela- tion those numbers have to each other. In forecasting profits, a small business owner might use a spread- sheet program and define profits quite simply: Profits are what’s left from Revenues after Costs of Do- ing Business have been met. The algebraic presentation in a spread- sheet would be Profits = (Revenues — Costs of Doing Business). Note that though Revenues or Costs of Doing Business might change, their relation to one another and to Pro- fits remains the same. A more sophisticated model might include Units Sold, Price, Unit Costs and Overhead. Algebraically, Profits = (Units Sold * Unit price) — (Units Sold * Unit Cost) + (Overhead). (See accom- panying figures.) Even at this level, the formulas are quite simple. A more sophisticated profit equation could include hun- dreds of variables from trade and volume discounts to interest pay- ments and inventory charges as Figure 3 suggests. This kind of com- plexity and repeated elaborations of the spreadsheet model open up enor- mous possibilities for spreadsheet er- ror and, unless discovered, spread- sheet disaster. THE PROBLEMS Specific problems can take many forms: here are several examples. 1. Formulas are inconsistent. The profit equation for one month or quarter is different from other simi- lar periods. This can occur in a var- iety of ways including simple mis- takes in construction, overwriting formulas with other formulas or data, or referencing a field which is used for consolidation or other purposes. 2. Formulas, though consistent, are logically incorrect. This is com- mon in spreadsheets of all sizes and complexities. Ways for this to hap- pen include: simply omitting some entities; misgrouping brackets for isolating algebraic operations; add- ing subtotals instead of subtracting (or vice versa); applying the wrong formula (even though you use it cor- rectly) to a particular function, for example, using a logarithmic growth formula for compound growth; simply omitting some entities. 3. Formulas may reference them- selves, other data or formulas that contribute to their construction. This problem, known as “circular referencing)’ leads to a formula feeding on itself, producing even larger or smaller results as you repeat calculations. 4. Data may be reported in con- flicting magnitudes. Spreadsheet analysts commonly represent mil- lions as thousands. Reconversion (using the thousand figure literally in other parts of the spreadsheet) or misinterpretation by other users may lead to confusion and error. This problem is especially troublesome when consolidation of several spreadsheets is involved, such as when departmental budgets are summed into a company budget. 5. Spreadsheet output is applied inappropriately. “Profits” may mean one thing for financial ac- counting and something entirely dif- ferent for tax accounting or budgeting purposes. Similar amounts entered into the wrong spreadsheet or wrong spreadsheet cell could prove difficult or impossi- ble to reconcile. Gross errors result- ing from these problems usually stand out quickly. The real hazard comes when errors are subtle or when proven spreadsheets are mod- ified without the user being aware of their changed structure or functioning. In these cases, errors frequently go unnoticed. Even when someone does detect them, they are often im- possible to isolate. Imagine having to “cursor” through hundreds or even thousands of cells, reading one for- mula at a time, trying to track down, a problem! And, spreadshe