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CP/M creator Gary Kildall's memoirs released as free download

(spectrum.ieee.org)
244 points rbanffy | 1 comments | 18 Jul 25 10:22 UTC | HN request time: 0s | source
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csense ◴[18 Jul 25 16:07 UTC] No.44606352[source]▶
"Glenn came to my tool shed computer room in 1975, so we could "adapt" CP/M to the IMSAI hardware. What this means is that I would rewrite the parts of CP/M that manage things like diskette controllers and CRTs.

Well. come on, I'd already done this so many times that the tips of my fingers were wearing thin, so I designed a general interface, which I called the BIOS (BASIC I/O System) that a good programmer could change on the spot for their hardware. This little BIOS arrangement was the secret to the success of CP/M.

With the BIOS in place, a programmer could make CP/M work with their specialized hardware. With all those hobbyists out there, believe me, there was no shortage of specialized hardware. Glenn and I built a BIOS that afternoon and stuck CP/M on an IMSAI. He demo'd it to Ed Faber and the IMSAI engineers, and they loved it."

Writing a BIOS for a new machine in a single afternoon. Those were the days...

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WalterBright ◴[18 Jul 25 16:14 UTC] No.44606433[source]▶
In retrospect, MS-DOS was a rather trivial program. Sometimes I wonder why I and/or many others did not write an equivalent, even just for fun.
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1. zozbot234 ◴[18 Jul 25 16:18 UTC] No.44606487[source]▶
There wasn't much of a point in writing a replacement when MS-DOS was bundled with your computer. The FreeDOS project only got started when Microsoft first announced that the then-new Windows 95 would start to move away from MS-DOS and people saw the writing on the wall.