[TUHS] Re: UNIX on (not quite bare) System/370

[Clem Cole <clemc@ccc.com>]

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On Mon, Dec 19, 2022 at 1:54 PM segaloco via TUHS <tuhs@tuhs.org> wrote:

> All I can comment is there are a number of #ifdef u370 sections added to
> System V.  Happened somewhere between 3.0 and 5.0, likely UNIX/TS.  This is
> my understanding of Bell-adjacent platform work:
>
> PDP-7          - Research, 1969
> PDP-11         - Research, 1970
> Interdata 8/32 - Research, 1977
> VAX            - Research, 1979 (or did USG do 32V, it's sitting in my USG
> folder...)
> 3B20           - UNIX/TS 4.x, 1981
> System/370     - UNIX/TS?, 198x
> 3B5            - Release 5.0, 1982
> M68000         - System V, 1983
> Z8000          - System V, 1983
>
>
Sadly, do I wish it was this linear as you present ;-)    Simply - it was
not.

Just like the folks outside of the Bell System, inside, there were several
forks, many of which have been discussed here.

Research was its own bloodline.  Ken/Dennis et al..   This, of course, was
what seeded much of the external work at the Universities with the BSD
bloodline as a direct result. There was a good bit of porting work done
there, such as the work on the Interdata,  IBM S/360,  and Honeywell, but
most of that work tended to leave the labs in an indirect form.

PWB 1.0/2.0 started a different thread - Glaser, Mashey, et al...  as a
fork of Research Sixth Edition.  After many twists and turns, that
bloodline would become the Unix Support Group (a.k.a. USG) in Summit (Steve
Johnson - a.k.a. yaccman - was a manager in Summit and has offered some
enlightenment on this list over the years).  As we have often discussed
here, the TS line is hugely impure.  There is a great question of what was
TS and what was not.  What was the name and what was actual technology?
It's clear it started based on AT&T politics of the mid-late 70s, but as
things changed at AT&T and their own internal Unix wars - names and
technologies shave been blurred and some of the details were lost to time.
 We know that the PWB thread  (and >>name<< ) would >>eventually<< become
the many flavors of Sys V and it was the 'official' line that AT&T started
to market -- at first to the Operating Companies and later more widespread
commercially.  What was PWB and what was TS is not completely clear? (I
think Werner may have done so of the best sleuthing here and has reported
his learnings in the past).

Part of the issues we have as historians was because threads and those
twists and turns started before the breakup and were controlled by rules of
the 1956 consent decree (TS and PWB itself are examples) and other things
happened afterward as Charlie Brown (AT&T CEO) wanted to make a run at
being in the computer business.  Pre breakup, the AT&T >>commercial<< work
was targeted for the Operating Companys. Each group often did different
things to deal with specific projects that were being targeted to solve
problems that the OCs had.

As was pointed out before, the switching folks in Indian Hill not only
needed to build things like SW for the ESS#5 (the 370/TSS-based stuff
mentioned yesterday helped to support that project) but they were also
working on a very slick single system image Unix system [Tom Bishop at
friends] that ran on the 3B duplex and some other HW - the /400 IIRC]
(FWIW: Tom used to be findable - I've tried to get him on this list a few
times).  But you will see some #ifdefs in various codes that ended back up
in Summit that really are from that work.   That said, if I understand
things that have been suggested here, officially the Duplex system used an
OS that Indian Hill created but was >>seeded<< from Summit, but not the
Summit released directly [i.e., IH acted the same way as DEC, Sun, IBM, etc
might have].

Holmdel ( Reisner et al.) had several projects.  The best we3 can tell,
is that bloodline seems to have died off due to some internal AT&T politics
and reorgs, although a  number of things from it seem to have shown up in
other bloodlines and different people brought some of the ideas.  For
instance, while it's not directly there, SVR3's memory system >>seems<< to
have had some Reisner's influence.   Again we don't have direct evidence
other than different people's recollections and some comments people here
and elsewhere have found in different sources.

Columbus ( Dale's team ) did a great deal of work in several areas.  Some
of it has been recovered, but not all.  Mary Ann, is a one-time member of
that team and often comments and fills in some of the history here.  FWIW:
The PWB 3.0, a.k.a. System III release, got a bunch of the technology from
CBUNIX (again discussed at length here over the years) - shared mem,
semaphore, ipc, etc.

These are just a few and I apologize to anyone that was not mentioned.  I
offered some highlights to make my point.

If you are newer to the list, I respectfully suggest that instead of
restarting some of this discussion, please go back into the old Mail
archives and you will see a great deal of detail.

The most important point I will leave you with is that the different UNIX
flavors influenced each other - inside and outside the Bell System.  As
Larry points out, politics often had a more substantial influence on what
'won' than the 'goodness' of the technology itself in many cases.  But the
path from the root to any of the leaves includes a great deal of
cross-fertilization. It seems to me to be a bit disingenuous to offer a
linear statement from one of the bloodlines and infer that was how it all
worked, just because some #ifdefs have been found in a few places in some
of the different pieces of code, be kernel portions or user space.
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