Tough to Diagnose issue with PDP 11/40 CPU

Noel Chiappa jnc at
Thu Jun 30 09:21:05 CDT 2016

    > From: William Degnan

    > The problem was a missing KJ11

Ah. Well, if you want to add one (I assume you've just re-jumpered the
machine for the moment), I do have one we can copy (for the PC etch) - I'm
assuming here that originals are now unobtainium.

Also, if you have the KE11-E, but not the KE11-F (the former is a prereq for
the latter), and would like one, I have one I have no use for (Unix doesn't
use that version of the PDP-11 floating point), and would be willing to trade
it for something I do have a use for.

    > My error. Lesson: Always check everything.

Yes, always a good rule when dealing with recovered machines. I always take
them apart and go through them completely, verifying all cables, etc from the
original documentation.


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