$3.00 December-January 1987 Low Level Projects From Boots To Device Drivers: Secrets Of MS-DOS . ...... 6 A clean, in-depth look at making MS-DOS work for you. Debugging A Disk .................................... 12 This companion to "Secrets of MS-DOS" uses DEBUG to poke around in MS-DOS. Professionalize Your Programs Using Turbo Pascal's Built-in System Procedures . ............. 16 Turbo Pascal gives you assembly language style access to MS-DOS interrupts. Controlling The Real World With Your PC: Intro To Electronics Step 2 ............................. 22 This is the second part of Bruce's fine series. A great hardware primer. PD-32: Messages From The Board . ..................... 28 The Public Domain 32000 system is hot. The latest developments. Selecting Subsets From Sets: N The Formula For Combinations In Prolog . .............. 34 ,., Real-life solutions to. real-life problems. 00 00 r<"I Introduction To Fractals-. .............................. 36 0-.- 0 If you haven't watched a fractal eat its way across I'- ~ your screen, you've missed something. ~ I'- 0 - '/r -. " "~ ,~ Borland's Turbo Lightning FREE , '~ ,: -:' .', .,\;;; : ....,. - ---;:::.:;::::' :-, ~ '<.":~.; ;:~. ::: .' .... ;<; .; ... :~: ~:::. ,-, ;~ Extra~wide,easy~to­ '......... ,CiiPSr;N¥~'agd . •... ~., ~e~~r~te·t' find Rf!tum key..... ' .. ' ..• . Scroll.Lock '. ,dedicated . IBM changed Sizes' . indicator lights;. NiiineiiCPad again by shrinking their ..... .. IBM has no lights with enlargeq /' Return key. --....----..; . orfthelr xr. '. £nre; key,foilr •Arithmetic -....;.....;..-.- Function keys . Switch­ selectable . compatibility ... with IBM, PC; XT, AT,' PCjr, AT&T and all .' compatibles. IBM's new Enhanced Keyboard runs only on their newXTs,ATs and ignores their installed base which . probably in­ c/iJdes you . .......---..:..... Switch allows you ---- . to swap position of Ctrl and Caps lock. DESK'S IBM moved Ctrl to bottom row, you have nochoicet 101 ENHANCED KEYBOARD for the 10 million PC users IBM just ignored! IBM just announced their new The Turbo-101 Is the best data entry tool Up to now, DataDesk International may be one of redesigned "standard" keyboard for per­ since the pencil! the best kept secrets, but here's what's being said sonal computers. There's only one problem: For users of spreadsheets like 1-2-3, the about our first end-user Keyboard/Borland it won't work on your IBM computer if it Turbo-101's separate cursor controls and software bundle: was purchased priortoJune 19860ron any numeric keypad makes entering numeric "Wbo Can Pass up a Deal? "It's a good keyboard. Good PC compatible purchased at any time! data into cells and moving from cell to cell Department. Talk about an feel: tbe keys have tactile aggressive product!" feedback. No musb at all. Not to worry. Our new Turbo-101 Enhanced as natural as moving your fingers. And for Jobn C. Dvorak, This is about as good a key­ InfoWorld Mar 86 board deal as you're likely Keyboard gives you the layout and en­ word-processing, the 'Selectric' typewriter layout makes the Turbo-101as easy to "It solves all oftbe problems toflnd... 1 bave absolutely no hancements of the IBM with some logical exblblted by tbelr regular besltatlon In recommend­ improvements (see above photo). And it use as a pencil; and with the extra large \ PC/XT keyboard... It's a Ing tbe Model PC8700." Enter, Shift & Control Keys, you'll make so great bargain!" Jerry Pournellf:. works on your existing PC, XT, AT, PCjr, Byte Magazine Sept. 86 few mistakes, you won't even need an PC Productivity Digest AT&T, Epson and virtually all compatibles! May 86 "This keyboard Is neat to eraser! "DataDesk Inti. bas designed type on and feels solid. It Get Borland's Turbo Lightning ™ a sturdy and bandsome key­ bas tactilefeedback keys... 1 For FREE! board tbat bas tactile re­ can type m~chfaster on It." SPECIAL OFFER! sponse... is tbe bardware Test Drive Scorecard: DataDesk-l0 Key Tronlcs-9 To really turbocharge / $149.95* FOR BOTH bargain oftbe year" says ONLY Cbarles Humble, Oregonian Teleconnect Magazine your productivity, we are·/ .. .' May 86 I KEYBOARD & SOFTWARE Jan 86 including, tree-ot-charge, ~. .. ." Includes 30-day money back guarantee and 2 year full warranty. B?rlan.d's red-hot 7i.. ... ' .i.;"'.. .•.:.H.: ....., .•. Llghtnmg sottware ur~owith .' / ·····r:~ To prove that we don't ignore you each keyboard. Now, or your pocketbook, you get our when using SideKick, WordPerfect, Micro­ Turbo-101 Enhanced Keyboard and soft Word, 1-2-3 or most popular programs, Borland's Turbo Lightning for an our Turbo-101 Keyboard will check your astounding $149.95.* No, you didn't spelling as you type, gives you instant read it wrong. During this amazing access to Random House's 80,000-word Introductory Offer you get both Concise Dictionary and 60,000-word keyboard and software for Jess Thesaurus and much, much more! than most software programs ; "Lightning's good enough to make by themselvesl Now, if you're programmers and 'users cheer, executives still feeling ignored, you can ofother software companies weep," says always do what you-know-who Jim Seymour of PC Week. Sold separately, fThrbo Lightning retails for '99.951 wants you to do, ..and buy a new computer to get their keyboard! credit card orders call (800) 826-5398 in CA ca/l INTERNATIONAL (800) 592-9602 7650 Haskell Avenue 'Price does not include adaptor Van Nuys, California 91406 (818) 780-1673 cables required by certain compat· ibles • A limited offer-price subject Turbo-l0l is a trademark of DataDesk International. Turbo Lightning is a to change without notification. trademark of Borland International. IBM and IBM AT are registered trade­ marks of International Business Machines, Inc. 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I always ask for a window seat so I can make nose impressions on the plexiglass. It was dusk as we departed Chicago so I watched as small towns were swallowed up in the deepening twilight. Soon, however, they reappeared below us, twinkling like reflected stars.