Did you know that Microsoft made their own version of UNIX, all the way back as far as 1979, before MS-DOS and Windows was even a thing!? As usual, no story of computing folklore would be complete without a bit of controversy, and the story of Xenix is not short of a fair few crazy moments! Controversy aside, I bet you’ll learn a good bit about a bit of history today, that could have changed the way we see and use computers a whole lot, if Xenix had won the day. Get ready for a compelling story!
Learn about: Legal battles! Product mergers! Acquisitions! UNIX on the original PC and Apple Lisa! Steve Ballmer on Cocaine!
IBM therefore decided that sooner or later — and preferably sooner — MS-DOS simply had to go.
This much was obvious. What was less obvious was where this new-from-the-ground-up IBM operating system should come from. Over months of debate, IBM’s management broke down into three camps.
One camp advocated buying or licensing Unix, a tremendously sophisticated and flexible operating system born at AT&T’s Bell Labs. Unix was beloved by hackers everywhere, but remained under the thumb of AT&T, who licensed it to third parties with the wherewithal to pay for it. Ironically, Microsoft had had a Unix license for years, using it to create a product they called Xenix, by far the most widely used version of Unix on microcomputers during the early 1980s. Indeed, their version of Xenix for the 80286 had of late become the best way for ambitious users not willing to settle for MS-DOS to take full advantage of the PC/AT’s capabilities. Being an already extant operating system which Microsoft among others had been running on high-end microcomputers for years, a version of Unix for the business-microcomputing masses could presumably be put together fairly quickly, whether by Microsoft or by IBM themselves.
In page 286 of Byte Magazine - Inside the IBM PC one of the main advantages of MS-DOS 2.0 is supposed to be its Xenix compatibility. That is why MS-DOS 1 had CP/M style system calls while MS-DOS 2 added Unix style ones.