[pups] Interesting PDP/Xenix History

Michael Davidson MichaelDavidson at pacbell.net
Thu Mar 28 09:58:13 AEST 2002

Lars Buitinck wrote:

>I'm getting really confused with all these companies.  If I understand
It  was all very complicated ...
... much too complicated to describe accurately in a short piece of email.

One thing to understand is that the companies that you mention (and, of
course, many others, all had ongoing relationships with each other that
often lasted for a period of several years, so licenses and technology
transfers weren't usually just "one-time" events.

I have added a few comments below which may help to add to the confusion.

>AT&T/Western Electric sold UNIX rights to Microsoft.
Not exactly. The only time that UNIX *rights* were really *sold* or 
were with the various changes in ownership of the group which developed
UNIX. ie the USL -> Novell -> SCO -> Caldera  series of transactions.

Microsoft was just another licensee of various versions of UNIX, starting
with V7 and ending up with System V Release 3.2

>Microsoft had HCR develop XENIX from V7.
Once again it isn't as simple as that - I'm not sure of the exact 
sequence of
events - HCR (which was acquired by SCO in the early 1990's)  was yet
another independent licensee of various versions of UNIX and had done
work on both V6 and V7. Perhaps Mike Tilson can shed some more
light on exactly what went on back in those days - I will ask him when I
get the chance.

>SCO licensed XENIX from Microsoft.

>SCO then subsubsublicensed XENIX to various vendors.
Yes, although SCO's main business was in selling shrinkwrapped OS
products for standard Intel hardware - SCO did sublicense the code
to a few people - mainly large OEMs.

More information about the TUHS mailing list