The Microsoft Linux-Xenix

Category Linux, Soft | Permalink | 30. May 2007

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History of Xenix

Microsoft created their own variant of the unix operating system called xenix. They purchased a license for Version 7 Unix from AT&T in 1979, and announced on August 25, 1980 that it would make it available for the 16-bit microcomputer market.

Xenix varied from its 7th Edition origins by incorporating elements from BSD, and soon possessed the most widely installed base of any Unix flavour due to the popularity of the inexpensive x86 processor, even though the port created for Tandy Corporation computers proved to be more robust.

Microsoft did not sell Xenix directly to end users; instead, they licensed it to software OEMs such as Intel, Tandy, Altos and SCO, who then ported it to their own proprietary computer architectures. Microsoft Xenix originally ran on the PDP-11; the first port was for the Zilog Z8001 16-bit processor. Altos shipped a version for their computers early in 1982, Tandy Corporation shipped TRS-XENIX for their 68000-based systems in January 1983, and SCO released their port to the Intel 8086 processor in September 1983. A port to the 68000-based Apple Lisa also existed. At the time, Xenix was based on AT&T’s UNIX System III.

Version 2.0 of Xenix was released in 1985 and was based on UNIX System V. An update numbered 2.1.1 added support for the Intel 80286 processor. Subsequent releases improved System V compatibility.

The end of an era

Xenix served as a workhorse for small businesses. It had the following features that many businesses were looking for in an operating system:

Simple, small, and stable
Unlimited-user licenses
Command-line administration

With all of the benefits, Xenix had some major disadvantages. CD-ROMs, PCI, and mice were not supported (or barely functional) and it just barely supported SCSI disks and tapes, or Networking.

Later versions of Xenix did have networking support (and increased hardware support), but by this time, Linux had already started making its way into the business world.