(from Wikipedia) Xenix is a discontinued version of the Unix operating system for various microcomputer platforms, licensed by Microsoft from AT&T Corporation in the late 1970s. The Santa Cruz Operation (SCO) later acquired exclusive rights to the software, and eventually replaced it with SCO UNIX (now known as SCO OpenServer). SCO Xenix for the PC XT shipped sometime in 1984 and contained some enhancement from 4.2BSD; it also supported the Micnet local area networking. In the mid-to-late 1980s, Xenix was the most common Unix variant, measured according to the number of machines on which it was installed. sco-xenix86-2.1.3.zip contains a bootable hard disk image and is copied from http://www.hampa.ch/pub/pce/pre/pce-20170208-df19414/machines/pce-20170208-df19414-xt-xenix86-2.1.3.zip