[TUHS] PG3 or Gen3.0?

[Thalia Archibald via TUHS]

Interestingly, Pirzada calls it “issue 1 of UNIX Operating System Generic
PG-1C300”, never “Program Generic”.

These are the Generic releases mentioned by Pirzada:
- USG release 1.0 (15 December 1973)
- PG-1C300 issue 1: USG release 2 mod level 2.24 (April 1974)
- PG-1C300 issue 2: USG system at mod level 3.33 (January 1976) 
- PG-1C300 issue 3 (spring 1977)

Additionally with the same number scheme:
- PG-1C600: MERT Release 0 (November 1977)

Thalia

> On May 7, 2026, at 16:55, segaloco via TUHS <tuhs at tuhs.org> wrote:
> 
> Received a question from Thalia Archibald concerning my use of the
> nomenclature "PG3" vs Pirzada's "Gen3.0".  I pulled together the info
> below, seems like it might be interesting to the broader audience:
> 
> So it's a bit fuzzy when you get into the weeds. This document[1]
> defines the acronym "PG" as such:
> 
>> At the highest level in the document hierarchy is the
>> Program Document (PG) Index that lists all of the documents
>> associated with a program generic.  A single PG-level directory
>> occupies the corresponding position in the file system hierarchy.
> 
> So within their source control structure you would have directories:
> 
> pg-1c300-01 (issue 1)
> pg-1c300-02 (issue 2)
> 
> And then under those the "PR" directories containing the individual
> groupings of source files, other documents, etc.
> 
> This isn't what I originally based my use of this acronym on though,
> rather just Program Generic (PG).
> Typically if I do see a shorter name,
> the system is just referred to as a "Generic", proper noun. This was
> common practice within AT&T and did not just apply to UNIX[2][3].
> In fact, this first round of USG UNIX (before UNIX/TS and later) was
> very "Bell-ish" compared to later efforts. The manuals were the only
> ones rendered to Bell System standards in that they had the OSD headers
> with document ID, issue, date, etc. rather than just the standard
> manpage masthead. Several of the USG documents of the time look like
> the same typesetting package used for 3ESS generic pidents for instance.
> 
> As I was gathering some of this info, I keep seeing PG-1C300 used where
> the system is referred to in short.  This actually makes sense given
> AT&T's use of the "PG" prefix for a number of different projects.
> For instance, MERT Release 0 is given as PG-1C600[4]. COSMOS, built
> on UNIX by WECo for a frame system in telco offices[5], has
> documentation given as PA-6P014, possibly implying a PG-6Pxxx prefix
> for the underlying generic. Outside of UNIX, PG-3H903 is one of the
> 3ESS generics[6].
> 
> After compiling all of that info, I'm inclined to say that the
> "canonical" names in increasing length are "PG-1C300", then "Generic",
> then "Program Generic". I would think given Pirzada's being at AT&T
> at the time though the "Gen3.0" etc. nomenclature would also be
> acceptable, just maybe not "period".
> 
> - Matt G.
> 
> P.S. As always this is just my own research, I wasn't there so I'd
> certainly get some second opinions if available.
> 
> [1] - https://www.tuhs.org/Archive/Documentation/TechReports/USG_Library/1099_Program_Generic_Control_and_Documentation_on_UNIX.pdf
> [2] - https://telecomarchive.s3.us-east-2.amazonaws.com/docs/bsp-archive/233/233-154-135_I1.pdf
> [3] - https://telecomarchive.s3.us-east-2.amazonaws.com/docs/bsp-archive/234/234-090-161_I1.pdf
> [4] - https://www.tuhs.org/Archive/Documentation/Manuals/MERT_Release_0/Pgs 01-02 Title Page.pdf
> [5] - https://telecomarchive.s3.us-east-2.amazonaws.com/docs/bsp-archive/SPCS/PA-6P014_I3.pdf
> [6] - https://telecomarchive.s3.us-east-2.amazonaws.com/docs/bsp-archive/SPCS/PG-3H903_I10.pdf