Am 17.08.2021 um 17:40 schrieb Warner Losh <imp at
bsdimp.com>:
Having looked at the sources to both and running diffs with tuhs, I can confirm this is
the case. And ultrix-32 had different version numbers than ultrix-11. But the vax and mips
versions shared the same sources as far as I can tell (though I don't know if it is
common ancestor or operationally the same repo).
Ultrix-32 for RISC (=MIPS) was developed based on the VAX version,
which was also Ultrix-32. DEC dropped the ?-32? with Ultrix 4.
The DECstation 3100 came out in 1989. I don?t have sources for
Ultrix-32 version 3.X, but Ultrix versions 4.X just share sources.
It is clear that Ultrix/RISC added a few bits and pieces from MIPS,
but it?s nothing that would prevent a common source tree.
As far as I remember, the name ?-32? came from the first Ultrix
release, which was ?32m? version 1.0 or something like that. ?32?
meaning 32bit VAX and ?m? meaning ?MicroVAX?. A bunch of
RX50 floppy images from 1984 (or 85?) have been preserved, I think?
AFAIR the first Ultrix-32 only ran on the MicroVAX I.
Dennis