PDP-11/73 questions

From: Dennis Boone <drb_at_msu.edu>
Date: Tue Nov 9 18:32:44 2004

I found an OEM 11/73 at Salvage this morning. It was built by Netcom.
I'm trying to identify a few boards that are in it. Wonder if anyone
can help?

There's a pair of double-width boards marked KHV1, one says "COMMS
CHIPCARD", the other says "DMA CARD". The boards are connected by
a wide ribbon cable. The latter has a handwritten tape label which
says "Modified 422 / DTR tied active / provides xmit clks". I take
this to mean this is some type of RS-422 interface, but can't find
any notes about it online.

The other item (two of them, actually, identical) has virtually no
identifying markings. It's a quad width board, marked "(C) Orange,
CA 92665". The reverse has a small icon of a whale, and says
"MOEBI QUICK". There may be text under then handles, but they're
essentially riveted onto the board. In the center of the back edge
of the board, there's a wide ribbon cable connector. Multiport serial
boards perhaps?

I believe this was probably a Merit SCP machine (node CES1), for anyone
who was around educational networking in Michigan over 15 years ago.
There's a board in the machine which is definitely a custom item,
marked "MFV (C) 1984 UMNET", which I'm sure was developed by the U of
Michigan/Merit folks. The latter appears to have its own processor,
EPROMs, etc.

The other boards in the machine are the CPU, and a DEC 128k RAM board.

Images (warning: LARGE, about 3 MB each) are at:

        http://yagi.h-net.msu.edu/img_1282.jpg (quad board)
        http://yagi.h-net.msu.edu/img_1284.jpg (double board, COMMS)
        http://yagi.h-net.msu.edu/img_1286.jpg (double board, DMA)

Any assistance would be much appreciated.

Dennis Boone
Received on Tue Nov 09 2004 - 18:32:44 GMT

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