The earliest known version of 86-DOS, which is basically the great grandfather of Microsoft DOS has arrived on the internet, thanks to a tech enthusiast who has uploaded the version to the Archive.
Xenix RSS
Long before Windows, and even before MS-DOS, Microsoft sold a Unix-based operating system it called Xenix in 1980. It was the first OS made by the company, but it eventually sold it off in 1987.
Windows, MS-DOS, OS/2... and Xenix? Once upon a time, Microsoft was selling the world's most popular version of Unix, and rumor has it that they even used it to develop DOS and Windows.
