October 1979 S2.50 kilobaud MICROCOMPUTING for business . education . FUN! In This Issue—35 Articles Including: Special Emphasis on 6800 Systems Six Articles The World Power Systems Scam page 56 Exatron's Stringy Floppy: a Mass Storage Alternative page 98 Ulysses in Computerland: in Quest of Business Systems page 128 Inexpensive Logic Analyzer page 172 Complete Table of Contents on page 5. Fpcot PEflGCM One-Drive System: S399. (40-track) & $675. (77-track) Two-Drive System: S795. (40-track drives) & S1350. (77-track drives) Three-Drive System: $1195. (40-track drives) & S2025. (77-track drives) Requires Expansion Interface. Level II BASIC & 16K RAM Low Cost Add-On Storage for Your TRS-80*. In the Size You Want. When you're ready for add-on disk storage, we're ready for you. Ready with six mini-disk storage systems — 102K bytes to 591K bytes of additional on-line storage for your TRS-80*. • Choose either 40-track TFD-100™ drives Whether you need a single, 40- — 197K, 394K and 591K bytes for one-, or 77-track TFD-200™ drives. track TFD-100™ add-on or a three-drive two and three-drive systems. add-on with 77-track TFD-200™s, you PATCH PAK #1™, our upgrade • One-, two- and three-drive systems im- get more data storage for less money program for your TRSDOS*, not only mediately available. from Percom. extends TRSDOS* to accommodate 40- and 77-track drives, it enhances • Systems include Percom PATCH PAK Our TFD-100™ drive, for example, TRSDOS* in other ways as well. PATCH #1™, on disk, at no extra charge. PATCH lets you store 102.4K bytes of data on PAK #1™ is supplied with each drive PAK #1™de-glitches and upgrades one side of a disk — compared to 80K system at no additional charge. bytes on a TRS-80* mini-disk drive — TRSDOS* for 40- and 77-track operation. The reason you get more for less and 102.4K bytes on the other side, too. from Percom is simple. Peripherals are Something you can't do with a TRS-80* • TFD-100™ drives accommodate "flippy not a sideline at Percom. Selling disk drive. That's almost 205K bytes per disks." Store 205K bytes per mini-disk. systems and other peripherals is our mini-disk. • Low prices. A single-drive TFD-100™ main business — the reason you get costs just S399. Price includes PATCH And the TFD-200™ drives provide more engineering, more reliability and PAK #1™ disk. 197K bytes of on-line storage per drive more back up support for less money. > Enclosures are finished in system- In the Product Development Queue ... a printer interface for using your TRS-80' with any compatible "Tandy-silver" enamel. serial printer, and ... the Electric Crayon™ to map your computer memory onto your color TV screen — for games, animated shows, business displays, graphs, etc. Coming PDQ! ™ TFD-100. TFD-200 PATCH PAK and Electric Crayon are trademarks ot PERCOM DATA COMPANY •TRS-80 and TRSOOS are trademarks ol Tandy Corporation and Radio Shack wtiich have no relationship to PERCOM DATA COMPANY To order add-on mini-disk storage for your TRS-80*, or request additional literature, call Percom's toll-free number: 1-800-527-1592. For detailed Technical infor- mation call (214) 272-3421. PERQOM Orders may be paid by check or money order, or charged to Visa or Master Charge credit accounts. Texas residents must add 5% sales tax. PERCOM DATA COMPANY, INC. 211 N. KIRBY • GARLAND. TX. • 75042 Percom peripherals for personal computing' E NTRTEC DATA SYSTB^IS I SUPRBRAIN The Honor Graduate There's been a lot of talk lately debugger. And, with SuperBrain's office typewriter. Sophisticated about intelligent terminals with S-100 bus adapter, you can even add users will acclaim SuperBrain's twin small systems capability. And, it's a 10 megabyte disk! Z-80 processors which transfer data always the same. The systems More than an intelligent terminal, to the screen at 38 kilobaud! Inter- which make the grade in perfor- the SuperBrain outperforms many facing a printer or modem is no mance usually flunk the test in other systems costing three to five problem using SuperBrain's RS- price. At least that was the case times as much. Endowed with a 232C communications port. But best of all, you won't need a PhD in com- until the SuperBrain graduated with hefty amount of available software puter repair to maintain the Super- the highest PPR (Price/Perfor- (BASIC, FORTRAN, COBOL), the SuperBrain is ready to take on your Brain. Its single board design makes mance Ratio) in the history of the servicing a snap! industry. toughest assignment. You name it! General Ledger, Accounts Receiv- So don't be fooled by all the fresh- For less than $3,000*, SuperBrain able, Payroll, Inventory or Word Pro- man students in the small systems users get exceptional performance cessing ... the SuperBrain handles business. Insist on this year's honor for just a fraction of what they'd all of them with ease. graduate ... the SuperBrain. expect to pay. Standard features in- Your operators will praise the clude: two dual-density mini-flop- SuperBrain's good looks. A full = NTE3TEC pies with 320K bytes of disk storage, ASCII keyboard with a numeric key- 64K of RAM to handle even the most pad and function keys. A non-glare, DATA sophisticated programs, a CP/M • dynamically focused, twelve inch Disk Operating System with a high- = SYSTEMS screen. All in an attractive desktop 2300 Broad River Road, Columbia, SC 29210 powered text editor, assembler and unit weighing less than a standard (803) 798-9100 TWX: 810-666-2115 •Quantity one. Dealer inquiries invited. Solve your personal energy crisis. Let VisiCalc Power do the work. With a calculator, pencil and paper you can spend hours plan- Or say you're an engineer working on a design problem and are ning, projecting, writing, estimating, calculating, revising, erasing wondering "What if that oscillation were damped by another 10 and recalculating as you work toward a decision. percent?" Or you're working on your family's expenses and Or with VisiCalc and your Apple* II you can explore many wonder "What will happen to our entertainment budget if the more options with a fraction of the time and effort you've spent heating bill goes up 15 percent this winter?" VisiCalc responds before. instantly to show you all the consequences of any change. VisiCalc is a new breed of problem-solving software. Unlike Once you see VisiCalc in action, you'll think of many more prepackaged software that forces you into a computerized uses for its power. Ask your dealer for a demonstration and dis- straight jacket, VisiCalc adapts itself to any numerical problem cover how VisiCalc can help you in your professional work and you have. You enter numbers, alphabetic titles and formu- personal life. las on your keyboard. VisiCalc organizes and displays this You might find that VisiCalc alone is reason enough to information on the screen. You don't have to spend your own a personal computer. time programming. VisiCalc is available now for Apple II computers, with Your energy is better spent using the results than forother personal computers coming soon.The Apple gettiitg them. II version costs just $99.50 and requires a 32k disk system. Say you're a business manager and want to project For the name and address of your nearest VisiCalc your annual sales. Using the calculator, pencil and dealer, call (408) 745-7841 or write to Personal paper method, you'd lay out 12 months across a Software, Inc., Dept. K, 592 Weddell Dr., sheet and fill in lines and columns of figures Sunnyvale, CA 94086. If your favorite on products, outlets, salespeople, etc. You'd dealer doesn't already carry Personal calculate by hand the subtotals and summary Software products, ask him to figures. Then you'd start revising, erasing give us a call. and recalculating. With VisiCalc, you simply fill in the same figures on an electronic "sheet of paper" and let the computer do the work. Once your first projection is complete, you're ready to use VisiCalc's unique, powerful recalculation feature. It lets you ask "What if?',' examining new options and planning for contingencies. "What if" sales drop 20 percent in March? Just type in the sales figure. VisiCalc instantly updates all TM—VisiCalc is a trademark of other figures affected by March sales. Personal Software, Inc. 'Apple is a registered trademark of Apple Computer, Inc. kilobaud micro info T.M. [Iji This symbol next to a title in MICROCOMPUTING ™ the table of contents indicates that the article is a business- application article. Manuscripts Contributions in the form of manu- contend och '79 scripts with drawings and/or photo- graphs are welcome and will be con- sidered for possible publication. We The SWTP Computer System First ot a two-part series on disks for SWTP P. Shuman, P Stark 30 can assume no responsibility for loss or damage to any material. Please PAIA 8700 Revisited Continuing coverage ot the 8700. This time-making music. Rod Hallen 40 enclose a self-addressed, stamped Inexpensive TRS-80 Printer Interface Small System Hardware's TRS-232. Sherman P. Wantz envelope with each submission. Pay- 44 ment for the use of any unsolicited 46 Eyes for the AC-30 Mod to add monitoring features to the AC-30. Jerry Sorrels material will be made upon accep- tance. All contributions should be di- 48 Expanded TRS-80 Disk Operations First in a two-part series. Allan J.