[TUHS] PG3 or Gen3.0?

[segaloco via TUHS]

On Thursday, May 7th, 2026 at 18:19, Warner Losh via TUHS <tuhs at tuhs.org> wrote:

> "USG mod level 3.33" might be the best moniker.
> 
> Unix Operating System Generic makes the most sense to me, since Bell
> entities would take that and turn it into the specific OS for their switch,
> billing system, etc. USG curated the research products into something that
> people could use.
> 
> Warner
>

Pirzada's thesis gives these timeframes for USG's initial version:

73-12-15 - USG Release 1.0
74-04-?? - USG Release 2.0
74-11-?? - USG Release 2 mod 2.24 (PG Issue 1)
76-01-?? - USG Release 3.0 mod 3.33 (PG Issue 2)
77-03-?? - USG PG Issue 3 (No Release or mod number given).

So there was the release mod level and the issue of the generic.  This dual versioning scheme also appears in CB-UNIX, which has manuals featuring "Editions" like 2.1, 2.3, but then a kernel featuring "releases" like 2 and 3.  I've documented this situation a bit in the wiki here:

https://wiki.tuhs.org/doku.php?id=systems:cb1

By the way just to summarize since I've made a lot of noise about it but maybe haven't explained the basics: Program Generic Issue 3, or PG3 as I've been calling it, is the last "supported" USG release inside AT&T prior to reorganization of USG's efforts behind the UNIX/TS and ongoing PWB projects.  In particular, UNIX Program Generic was intended as a UNIX packaging that met BTL standards.  This made for several pecularities:

- Printed manuals (of which Issue 2 and Issue 3 are the only confirmed widely-printed releases) contained OSDD (Operations Systems Deliverable Documentation) headers, common to other BTL systems documentation in requiring the document code, date, issue number, etc. printed in the outer corner of the page, much like Bell System Practices (BSP) documents.
- The literature and sources themselves were arranged in this PG-, PA-, PD-, etc. nomenclature found in other AT&T projects like switching stuff in Columbus.
- Other AT&T projects built on top of Program Generic then cite it or at least adhere to similar documentation requirements such as COSMOS and MERT Release 0.

So yeah the "USG supported UNIX for the BTL user community" was one part of their responsibilities, but with Program Generic that also expanded to supporting UNIX as a standard AT&T OS for building telco and related systems on top of.  While UNIX was the in-house solution, AT&T also maintained standards for systems development on top of other operating systems such as OS 1100 and VMS.  Some documentation can be found here in BSP section 007 on Information Systems:

https://www.telecomarchive.com/007.html

Anywho, probably enough from the firehose on mid 70s USG activities for now.  I'm just so glad some of this stuff is finally preserved properly and folks are talking about it.  Program Generic in particular is very "Bell-ish" so tickles the overlap between my UNIX and telecom interests well.

- Matt G.