> When IBM made the PC, they wanted something like CP/M, so Microsoft took an 8086 port of CP/M and made it into MS-DOS.
It gets stranger than that.
MS-DOS was a clone of CP/M, not a port. And it wasn't originally made by Microsoft: it was made by Seattle Computer Products and called QDOS and later 86-DOS, and Microsoft bought it from them. As a side note, the name MS-DOS came later: the original version for the IBM PC was called "PC DOS", and the name "MS-DOS" first appeared when Microsoft began courting the clone market. The version of the OS for IBM products continued to be called PC DOS, and after Microsoft and IBM fell out, IBM continued to maintain PC DOS as an independent fork while Microsoft continued to develop MS-DOS.
But, getting back to the point...
IBM originally wanted a straight-up port of CP/M by the original author (Gary Kildall). When IBM tried to contact Kildall, he wasn't home, and his wife (who was officially his business partner) talked to them instead. His wife laid down a number of demands that made IBM wary of doing business with the Kildalls. So Microsoft swooped in and offered up DOS at a very low price. The IBM PC launched with PC DOS, written by Microsoft in collaboration with IBM.
Shortly after the launch, IBM patched things up with the Kildalls: Gary developed a port called CP/M-86 as part of the deal, and IBM offered their customers a choice of operating systems. By that point, though, IBM had negotiated a great deal with Microsoft and a very expensive deal with the Kildalls. An IBM PC equipped with PC DOS cost considerably less than an IBM PC equipped with CP/M-86, and nobody wanted to buy the latter when they could save a lot of money and buy the former. Besides, x80 CP/M apps wouldn't run on CP/M-86, and PC DOS had already built up a wealth of popular apps since it came out first, so CP/M-86 died in what was possibly the first instance of an "app gap".
I would argue that the very first instance of a true "app gap" occurred much earlier in computing, when the very first computer was replaced by the very second computer ever made, and it is a constant in computing so far ..
It gets stranger than that.
MS-DOS was a clone of CP/M, not a port. And it wasn't originally made by Microsoft: it was made by Seattle Computer Products and called QDOS and later 86-DOS, and Microsoft bought it from them. As a side note, the name MS-DOS came later: the original version for the IBM PC was called "PC DOS", and the name "MS-DOS" first appeared when Microsoft began courting the clone market. The version of the OS for IBM products continued to be called PC DOS, and after Microsoft and IBM fell out, IBM continued to maintain PC DOS as an independent fork while Microsoft continued to develop MS-DOS.
But, getting back to the point...
IBM originally wanted a straight-up port of CP/M by the original author (Gary Kildall). When IBM tried to contact Kildall, he wasn't home, and his wife (who was officially his business partner) talked to them instead. His wife laid down a number of demands that made IBM wary of doing business with the Kildalls. So Microsoft swooped in and offered up DOS at a very low price. The IBM PC launched with PC DOS, written by Microsoft in collaboration with IBM.
Shortly after the launch, IBM patched things up with the Kildalls: Gary developed a port called CP/M-86 as part of the deal, and IBM offered their customers a choice of operating systems. By that point, though, IBM had negotiated a great deal with Microsoft and a very expensive deal with the Kildalls. An IBM PC equipped with PC DOS cost considerably less than an IBM PC equipped with CP/M-86, and nobody wanted to buy the latter when they could save a lot of money and buy the former. Besides, x80 CP/M apps wouldn't run on CP/M-86, and PC DOS had already built up a wealth of popular apps since it came out first, so CP/M-86 died in what was possibly the first instance of an "app gap".