[TUHS] PDP-7 and Interdata 8/32 Bell System UNIX Installations?

Phil Budne phil at ultimate.com
Fri Dec 22 03:48:09 AEST 2023

Lars Brinkhoff wrote:
> The back story here is approximately something like the PDP-7 being left
> over from development of William Ninke's Graphic II display systen done
> in cooperation with DEC.

The fast fixed-head disk on the UNIX PDP-7 seems to have been the RB09
for the upcomming PDP-9, and it's been my surmise that the PDP-7 was
likely used until PDP-9s were available for "production" Graphic II
workstations.  I seem to recall the DEC Field Service list for 18-bit
systems only showed the one PDP-7, but multiple PDP-9's equipped with
an RB09.

While working on the PDP-7 UNIX resuscitation (I wrote a stand-in for
the shell, which served until the listings for utilities from the
second half of the alphabet were found and scanned) I once booted UNIX
on under SimH PDP-9 simulation.

I believe the same (Burroughs?) disk was used as the RD10 on PDP-10
systems as a swap device.


shows the RD10 subsystem was $32,500 in 1967.

https://gunkies.org/wiki/PDP-9 says an 8K system was $30K and that a
PDP-7 was $72K.

I don't doubt the custom Graphic II hardware was costly as well.  The
Graphic II project seems to have been well funded, and the demo videos
I've seen show the Graphic systems were meant for doing "real"
(telephone network) related work (I remember seeing one on filter
design), so I imagine the PDP-9 Graphic II systems were in use during
regular work hours.  The Graphic II systems had modem links to a
(GE635?) mainframe, so it's _possible_ the disk was only used for
fast/temporary storage, and it wouldn't matter if someone booted UNIX
after hours...

Ah... I found the simh .ini file I used:

phil at phil-nb9:~$ ls -l /home/phil/pdp7-unix/build/pdp9.simh
-rw-rw-r-- 1 phil phil 613 Mar 27  2016 /home/phil/pdp7-unix/build/pdp9.simh
phil at phil-nb9:~$ cat !$
cat /home/phil/pdp7-unix/build/pdp9.simh
set cpu 8k
set cpu eae
#set cpu history=100
show cpu

# set up SIMH devices:

# UNIX character translations (CR to NL, ESC to ALTMODE):
set tti unix

# RB09 fixed head disk:
set rb ena
att rb image.fs

# uncomment to TELNET in GRAPHICS-2 keyboard/display(!!)
# (requires github.com/philbudne/simh)
#set g2in ena
#att -U g2in 12345

# disable hardware UNIX-7 doesn't know about:
set lpt disa
set drm disa
set dt disa

# PDP-9 hardware
set ttix disa
set ttox disa
set mt disa
set rf disa

# show device settings:
show dev

# load and run the paper tape bootstrap
# (loads system from disk)
load boot.rim 010000

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