PDP-11 Xenix (LONG)

Greg Lehey grog at lemis.com
Mon Oct 13 09:50:43 AEST 1997

On Sun, Oct 12, 1997 at 03:49:22PM -0700, David C. Jenner wrote:

(excuse me if I reformat it; your mailer has jagged the paragraphs)
> Frank Wortner wrote:
>> Since I'm the one that started this --- albeit indirectly --- let me try to
>> explain.
>> Way back when --- about 1981 or 82 --- I worked for a small (now defunct)
>> software company.  We owned 2 PDP-11/23s.  Initially,  we ran a distribution
>> of the Sixth Edition on them.  That came from a company in New York ---
>> that's where I am geographically,  BTW --- called Yourdon.  The system was
>> called UV6.
>> After a while,  we decided to upgrade to V7.  At the time,  we had begun a
>> relationship with another (now defunct) firm called Lifeboat Associates
>> (also in New York,  later in Tarrytown, NY).  They distributed microcomputer
>> software,  principally CP/M-based.  They were a Microsoft distributor.
>> Microsoft had just started Unix development at the time.  Lifeboat sold us a
>> V7 system:  Microsoft PDP-11 Xenix.  I know it was Microsoft because the
>> tape lables said so, and I remember that the line printer printed release
>> notes contained a banner page that indicated that they came from Microsoft's
>> DEC 20(!) (cheerfully named "Microsoft Heating Plant").
>> PD.-11 Xenix was essentially V7,  but it had a few added features.
> snip
>> BTW,  if John or Bob reads this list,  l'd like to say "Thank you" to both
>> of them.  Also thanks to Warren for his work preserving the old Unix
>> software.  It's a great deal of fun to see old "friends" again,  and I think
>> it will be just as much fun to see software and "hardware" combinations that
>> I didn't have access to in the "good old days."  Thanks also to SCO for
>> binary licenses for these "historic" systems;  I hope that they will be able
>> to license source code in the near future.
> OK, Frank is likely correct.  But I still don't think you'll find it
> anywhere on the 'net!  It would be nice if it were in the PUP
> archives, though.  Getting it there might be hard because MS might
> still have some rights to it.

> I did some digging, and here are some relevant dates:

>  8/25/80 Microsoft announced DEC PDP-11 XENIX (along with versions
> for several other machines--Intel 8086, Zilog Z8000, and Motorola
> M68000).  [This would have to be Version 7 based.]

> 10/01/80 Microsoft notes PDP-11 XENIX is "scheduled for release".
> [It's not clear if this means it was actually released on that
> date.]

Somewhere in this time frame, Microsoft's Robert Greenberg wrote an
extensive article about XENIX for Byte ("The UNIX Operating System and
the XENIX Standard Operating Environment"), which was published in the
June 1981 issue.

Some quotes: 

  The XENIX operating environment combines two key elements: the
  design of the widely acclaimed UNIX operating system and the
  inclusion of the major high-level languages that are standard within
  th 8-bit micormcomputer world (see figure 1).  Microfosft's
  transport of the XENIX system to major 16-bit microprocessors has
  made it the first hardware-independent operating system.


  It had become clear that the support of a commercial software
  company was essential if UNIX was to become a software standard.  In
  August of 1980, Microsoft announced that it would offer and support
  XENIX, a commercial version of the operating system, on 16-bit
  microprocessors.  Working closely with Western Electric and a newly
  formed commercial users' organization, Microsoft intends to
  establish a standard industry version of UNIX that can provide a
  chightly productive environment worthy of meeting the challenges of
  software development in the 1980s.

> 12/08/81 Microsoft and SCO signed a letter of intent for SCO to be a
> second- source of XENIX.  [No mention of PDP-11; just that XENIX was
> being upgraded to System III at that time.]

This is interesting.  I had thought that SCO was Microsoft's UNIX
operation that gradually became disowned as DOS became predominant.  I
know that Microsoft maintained a significant interest (controlling?)
in SCO for a long time.  Do you have any indication of the
relationship between Microsoft and SCO at the time?

>  1/22/85 Microsoft and AT&T announce plans for compatible future
> releases of XENIX and UNIX [based on System V].

>  1/31/86 Microsoft and SCO announce new agreements for SCO to be
> prime distrubutor of XENIX System V to VAR and VAD channels.

>  2/15/89 Microsoft makes 20% minority investment in SCO.  [I seem to
> recall that SCO got (all?) XENIX rights at this time.]

> So it looks like there was a window of about a year when a Version 7
> based XENIX was probably available.  Certainly starting in 1983
> Microsoft announced all sorts of versions of XENIX for other
> hardware, including IBM System 9000 (yes, there really was a HAL
> 9000 (Motorola MC68000-based)--I had a couple), IBM PC/AT, AT&T UNIX
> PC and PC 6300, and Compaq machines.


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