[TUHS] Release Dates, Systems History - (was Did System V Really Prevent 5BSD?)

[Warner Losh via TUHS]

On Fri, Jan 2, 2026 at 4:32 PM Mary Ann Horton via TUHS <tuhs at tuhs.org>
wrote:

> On 12/29/25 13:10, Clem Cole via TUHS wrote:
> > - Initial Internal Release: Some sources indicate an initial release in
> >        1980. This was likely a pre-commercial version known internally
> by names
> >        such as UNIX/TS 3.0.1 or UNIX Release 3.0.
> >        - Official Commercial Release: AT&T formally announced System III
> in
> >        late 1981, and it was first made publicly (commercially)
> > available outside
> >        of the Bell System in 1982.
> My UNIX Release 3.0 manual is dated June 1980. It's from Dolotta,
> olsson, and Petruccelli, Lab 364. The Acknowledgements page describes it
> (the manual) as descended from V6, UNIX/TS 1.1, and PWB/UNIX 2.0. My
> understanding is that this eventually turned into System III.
> > AT&T's UNIX System V had major releases starting with the initial System
> V 1983,
>
> My UNIX Release 5.0 manual is dated June 1982. It was internal to Bell
> Labs Division 452 (the computer centers). I understand this turned into
> System V.
>

4.1BSD was July 1981
4.1aBSD was April 1982
4.1cBSD was  Late 1982

This leaves us with Kirk's story lining up in two possible ways:
1. If the reason is System V, then the dates line up well to 4.1->5.0 plans
    changing to 4.1->4.2.
2. If the reason is Unix 5.0 plans that were hatched when 3.0 was released,
    then it does line up with the 4->5BSD plans vs 4BSD -> 4.1BSD actual.

I'll see if I can get a peek at the dates of the printouts next time I'm at
Kirk's
house which would tell us for sure. He's quite sure the reason was AT&T.
I see now that I didn't ask this detail... I'll follow up with him.

Warner