Racmeister

Teknologi, fremtid, samfund

Computerhistorie: Selvbiografi fra manden, der lavede det første PC-styresystem


“Using the simulator, I developed all of the CP/M operating system in PL/M using a minicomputer. Just like the early days of the i4004, I used no hardware. But, by using the simulation, I knew that CP/M worked. I just couldn’t figure out how to make that damn disk drive work. I even made a program editor, the infamous ED that proved true under that simulator. This was 1974. Out of frustration, I called my good friend from the University of Washington, John Torode. John was a Ph.D. graduate of the Electrical Engineering Department there, and I figured if John couldn’t build that controller, no one could. He did build it. He designed a neat little microcontroller and, after a few months of hardware and software testing, that microcontroller started to work. We loaded my CP/M program from paper tape to the diskette, and “booted” CP/M from the diskette, and up came the prompt * This may have been one of the most exciting days of my life, except, of course, when I visited Niagara Falls One Day. We loaded ED onto the diskette, and I typed *ED The ED program editor came up quite well and alive. Ok, so far, so good. I made up a file with ED and put it to disk. The DIR command showed us the file was there, and the TYPE command showed us that what we typed was what we entered using the ED program.”

Ordene er et citat fra Gary Kildall’s aldrig tidligere udgivne selvbiografi. Den kan man nu læse, hvilket er en helt unik mulighed for at genopleve den helt særlige dirrende spænding, som computerverdenen var fuld af i 1980’erne.

Kildall døde i 1994 (var alkoholiker, så der er den triste del af hans liv).

Hvad der ikke er trist, er hans bidrag i 1970’erne og et stykke ind i 1980’erne.

Kildall skrev nemlig styresystemet CP/M, som var det første *rigtige* styresystem til mikrocomputere og det første *rigtige* styresystem, som jeg personligt havde mulighed for at eje en kopi af og bruge til noget på mine tidlige, Z80-baserede computere.

CP/M kunne det basale: Læse og skrive på disk, sende output til skærm, hente input fra tastatur osv. De helt fundamentale operationer, som en computer har brug for at kunne. Det var fantastisk for mig som ung nørd at skrive assembler i hånden, compilere og have et styresystem under til at tage sig af hardwaren.

Mærkeligt nok blev CP/M ikke den store vinder. Sådan lidt poppet genfortalt gik det i starten af 1980’erne op for IBM, at de skulle bygge en personlig computer (PC) og de skulle bruge et styresystem. De gik så til Kildall for at købe et styresystem (CP/M), men forhandlingerne gik i fisk. Han var ikke lige hjemme og hans kone ville ikke lige skrive under på en NDA.

“IBM approached Digital Research in 1980, at Bill Gates’ suggestion, to negotiate the purchase of a forthcoming version of CP/M called CP/M-86 for the IBM PC. Gary had left negotiations to his wife, Dorothy, as he usually did, while he and colleague Tom Rolander used Gary’s private airplane to deliver software to manufacturer Bill Godbout. Before the IBM representatives would explain the purpose of their visit, they insisted that Dorothy sign a non-disclosure agreement. On the advice of DRI attorney Gerry Davis, Dorothy refused to sign the agreement without Gary’s approval. Gary returned in the afternoon and tried to move the discussion with IBM forward, but accounts disagree on whether he signed the non-disclosure agreement, as well as if he ever met with the IBM representatives.” Citatet hentet fra Wikipedia.

Uden CP/M snakkede IBM videre med Microsoft. Det førte til DOS, MS-DOS, Windows, OS/2 og en hel masse software, som siden har sat normen i computerverdenen i tre årtier. Kildall var ude igen, men han havde lavet et meget fundamentalt første bidrag.

Og nu er der selvbiografien til rådighed. Start her.

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