[cctalk] Re: First non-IBM PC-DOS Compatible PC

On 6/5/23 22:28, Tom Gardner via cctalk wrote: That's a tricky one,I think. For example, if a single programmer read the IBM PC BIOS listing (or even disassembled it) and then wrote a new one from scratch, that derivative BIOS in the view of the IBM legal beagles would not have been legal. If, on the other hand, the same programmer never saw any of the code, but read the API description and wrote a BIOS, that would be legal. Both ERSO and Phoenix resorted to a "clean room" method where one team read the PC BIOS and wrote a description, which served as a specification for a derivative BIOS. I think that the descriptions were cleaned up a bit and published as the Phoenix BIOS books. But I think the first "clean room BIOS" was in the Columbia MPC-1600, June 1982. --Chuck