Is DOS a Rip-Off of CP/M?
Paterson v. Evans lawsuit dismissedIn his book They Made America (Little, Brown & Co., 2004), author Harold Evans revives claims that DOS is based on the late Gary Kildall's CP/M, using words such...
View ArticleThe Contributions of CP/M
Gary Kildall’s CP/M was the first general-purpose operating system (OS) for 8-bit computers. It demonstrated that it was possible to pare down the giant operating systems of mainframes and...
View ArticleDesign of DOS
I set to work writing an operating system (OS) for the 16-bit Intel 8086 microprocessor in April of 1980. At that point my employer, Seattle Computer Products (SCP), had been shipping their 8086...
View ArticleThe First DOS Machine
Seattle Computer Products (SCP) introduced their 8086 16-bit computer system in October 1979, nearly two years before the introduction of the IBM PC. By "computer system", I actually mean a set of...
View ArticleIBM PC Design Antics
The original IBM PC had a clock speed of 4.77 MHz. The 8088 processor inside was actually specified to run at 5 MHz, so how did IBM end up at 4.77?To tell that whole story we need to briefly transport...
View ArticleAll Those Floppy Disk Formats…
Seattle Computer Products adapted DOS to an array of floppy disk systems. We used North Star, Cromemco, and Tarbell floppy disk controllers, and later designed a floppy disk controller of our own (the...
View ArticlePaul Allen and I
I was recently given a copy of Paul Allen’s autobiography, Idea Man. I haven’t read it yet, but I’ve skimmed the parts where I had a role. And my first reaction is:Really Paul, you don’t know how to...
View Article
