Comments by "Scott Franco" (@scottfranco1962) on "The Man Who COULD Have Been Bill Gates [Gary Kildall]" video.

  1. No, it was not reverse engineered nor did it need to be. Many people made CP/M compatible systems, including ZCP/M and, ahem, me. In fact, CP/M was compiled from PL/I code (Gary's own language) and not assembly language. Compilers in those days weren't very good. No way would you have even wanted to use that code.
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  2. A bit overly simplistic. CP/M had serious technical shortcomings at the time of the introduction of the IBM-PC. CP/M had been around for several years by then on the 8080, then Z80 CPU (time did not begin with the IBM-PC). Much of this was due to the fact that CP/M, and the applications it ran, had to be stuffed into very little memory, 64kb (a tiny fraction of today's computers). CP/M did get translated into the 8086/88, but was still seriously behind technically. It required each application to keep its own file information, had no concept of where the end of a file was, and had limited support for applications greater than 64kb even on the 640kb IBM-PC. QDOS was a clean sheet compatible of CP/M, but didn't rip off Gary's code. Regardless, Microsoft rapidly improved the system far beyond its original implementation, with all of the limitations of CP/M addressed. Digital research actually did come back with GEM, a graphical environment that ran lighter and faster than Windows, and that is another story. The marketplace beat Gary. Nothing more.
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