[TUHS] Date madness

Noel Chiappa jnc at mercury.lcs.mit.edu
Thu Dec 14 06:22:26 AEST 2017

    > From: Tom Ivar Helbekkmo

    > My /83s have them, but I'm not so sure it's a feature of the CPU board:
    > there's this thought nagging in the back of my head that the ToY thing
    > actually sits in the front panel module with the various buttons on it.

/83 documentation seems to be very thin on the ground, alas.

It's definitely not the CPU; the KDJ11-B CPU (of the /83) manual
(EK-KDJ1B-UG-001) makes no mention of it; and in the PDP-11/94E System User
and Maintenance Guide (EK-KDJ1E-UG-001), section D.2 "PDP-11/94 and 11/84
Hardware Differences" (the /?3 and /?4 models use the same CPU board, but a
different backplane, with QBUS/UNIBUS converter, so this could equally well be
titled "PDP-11/93 and 11/83 Hardware Differences") says "Time of Year Clock",
indicating the 83/84 don't have one.

Several companies made after-market ToD clocks to plug into the QBUS, e.g.


Is something like that what your /83 has?


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