[TUHS] Can PDP-11/23 PLUS run Unix?

[Clem Cole via TUHS]

Below

On Fri, Feb 27, 2026 at 8:50 AM Noel Chiappa via TUHS <tuhs at tuhs.org> wrote:

>     > From: Matt Gilmore
>
>     > Here is a salient document:
>
>     > Therein Ted Kowalski describes the process of moving UNIX from the
>     > PDP-11/70 to the PDP-11/34
>
> Why he started with the /70 version, which is a far way more complicated
> than
> the /23 & /34, instead of the already extant /40 version, which is almost
> exactly what one needs for the /23 & /34, is completely unclear to me.
>
He didn't actually.   About 6 months before Ted arrived at CMU for his OYIC
master's time[IIRC Wayne Gramlich and Danny Klien had fingers in that pot
too], I worked on the 11/34 port of V6 to the 11/34.  We started with the
11/40 version and changed a few things that differed between the 40 and 34
(CMU-EE/CS did not have an 11/23 in the mid/late '70s).   Ted brought with
him the V6++/TS bits from USG.  We switched to his kernel and already had
his USG-based system running. [I think I have an archive of that system].


I believe he wrote that document in 1981 for USG release of Unix 4.0, as
documentation on the differences.