[TUHS] Attempting To Build NOSC and BBN UNIXs + ARPANET code

Noel Chiappa jnc at mercury.lcs.mit.edu
Sat Oct 15 06:30:29 AEST 2022

    >> Looking at net_vdh.h, it seems to be a "VDH-11C"
    >> ...
    >> I wasn't able to find anything out about it at all. (I have some
    >> hardcopy manuals for other ACC IMP interface products, and I was going
    >> to look in them to see if any of them listed its manual in a 'see
    >> also', but I can't find them.)

    > From: Lars Brinkhoff

    > Noel Chiappa wrote:

    >> Did VDH PDP-11's have a special VDH interface

    > Sorry, no idea.

That was a semi-rhetorical question; after I typed it, I did some looking,
and came up with the answer above, the ACC VDH-11.

I did eventually find the hardcopy manuals for other ACC IMP interface
products, but none of them mention the VDH11.

On a hunch, I looked to see if there was a VDH11 driver for ELF, and
sure enough, there was:


(If anyone wants to look at it, ktbl.sml hold the register definitions.)

With no manual for the device, and no museum catalog hits to show that
someone has one which hasn't been scanned in yet, that's probably a dead end,
although with the two drivers, one could probably mock up a rudimentary
programmming manual.

I'm not sure there's any point, though; using an LH/DH interface is going to
work as well, and those device are already supported.

    > From: Paul Ruizendaal

    > impio.c: available here:

Thanks for chasing those all down; I knew the BBN system was based on the NCP
Unix (called in this discussion the 'NOSC' system), so I figured it would
have the missing files, in some form.

Looking at a diff between the damaged impio.c in the NOSC tree, and the
impio.c in the BBN tree, there are some changes (in the section where we have
both versions) between the NOSC one and the BBN one, but it will probably be
possible to take the missing piece off the bank end of the BBN one and tack
it on to the NOSC one.

Somewhere in the document scans available online from DOD, there used to
be a long thing from the UIUC people who did the original NCP Unix. I don't
know if it included source; it might have.


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