[pups] PDP-9?

Johnny Billquist bqt at update.uu.se
Mon Aug 19 04:04:41 AEST 2002

On Sun, 18 Aug 2002, Lars Buitinck wrote:

> we all know that UNIX first ran on the PDP-7 and then on the PDP-11/20,
> but does anyone know anything about PDP-9 UNIX?  it\'s mentioned in \"The
> UNIX Time-Sharing System\" in the V7 manual:
> \"The earliest [version of UNIX] (circa 1969-70) ran on the Digital
> Equipment Corporation PDP-7 and -9 computers.\"

Hmmm, I cannot exactly answer that, but the PDP-7 and PDP-9 were both
18-bit machines, and somewhat compatible, I believe.
The whole line is (I believe):

PDP-4 -> PDP-7 -> PDP-9 -> PDP-15

So I guess that if you had it running on a PDP-7, you could probably
almost take the code unmodified and run it on the PDP-9.
The PDP-15 have a different bus (Unibus?) I believe, and thus,
peripherials are different from the predecessors.
This obviosuly affects the OS. :-)


Johnny Billquist                  || "I'm on a bus
                                  ||  on a psychedelic trip
email: bqt at update.uu.se           ||  Reading murder books
pdp is alive!                     ||  tryin' to stay hip" - B. Idol

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