(from Wikipedia)
PC/IX was the first Unix implementation for the IBM PC XT available
directly from IBM. According to Bob Blake, the PC/IX product manager
for IBM, their "primary objective was to make a credible Unix system -
[...] not try to 'IBM-ize' the product. PC-IX is System III Unix." PC/IX
was not however the first Unix port to the XT. Venix/86 preceded PC/IX
by about a year, although it was based on the older Version 7 Unix.

The main addition to PC/IX was the INed screen editor from ISC. INed
offered multiple windows and context-sensitive help, paragraph
justification and margin changes, although it was not a fully fledged
word processor. PC/IX omitted the System III FORTRAN compiler, the tar
file archiver and did not add BSD tools like vi or the C shell. One
reason for not porting these was that in PC/IX individual applications
were limited to a single segment of 64 KB of RAM.

pcix-1.0.zip holds bootable floppy and hard disk images, and is copied from
http://www.hampa.ch/pub/pce/pre/pce-20170208-df19414/machines/pce-20170208-df19414-xt-pcix-1.0.zip