11/23+ Console cables

Noel Chiappa jnc at mercury.lcs.mit.edu
Mon Feb 16 14:53:58 CST 2015

    > From: Roe Peterson

    > Really?

Really! :-)

I can see a crystal on the cabkit, and if you look at the interface spec
('Microcomputers and Memories', 1982, pg. 628), it's clear it must use the
External Clock for the baud rate to be switch selectable on the cabkit.

    > I always assumed the rotary switches just replaced the 4 bits from the
    > dipswitch.

That is the case for the KDJ11-B, which is why I assumed the same thing was
the situation with the 11/23+. But it's not...

    > Where can I find a schematic?

Good question. I would assume in the 11/23+ print set, but I looked there, and
couldn't find it. Maybe that print set (MP01236) is just for the CPU board
itself, and there's some other print set for the larger system, including the
cables, but I can't immediately think what I should look for.

FWIW, the part number for the cabkit is 54-15422-01.

(I think the 54- prefix means 'assembly', but I'm not sure. I should collect
a list of all the DEC part prefixes - I looked, but there doesn't seem to be


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