DEC Indicator Panels page

Noel Chiappa jnc at
Fri Aug 19 20:31:12 CDT 2016

    > From: Mike Ross

    >> It seems to be always near the CPU ... there are only a few
    >> possibilities: BA15 (paper tape controller), DW15A (bus converter),
    >> KE15 (extended arithmetic), MM15-A and MK15-A (memory). It might also
    >> be a BD15 ... since that was listed as having an insert for it.

It turns out the KE15 registers are available on the main console, with a
setting on the rotary 'select registers to display' switch.

    > I'm not aware of any memory indicator panels associated with
    > any pdp-15 configuration

I was just being complete/thorough... :-)

    > Bingo!
    > BA15 & TC15 (and many other pics)

Oooh, thanks ever so much for turning that up!!!

So that mystery panel seems to be a general panel, more associated with the

but one quadrant is the KT15 memory management, one is the KA15 priority
interrupt system, and there's general CPU/system stuff throughout (memory
parity, power fail, instruction register).

I'm not sure what it's formal name might be (I don't think it can be BA15,
given all the CPU stuff that's in it). Very odd that the User's Handbook
doesn't cover it when it covers the KT15, the KA15, etc, etc; the print set
might be informative (now that I can see what's on that panel).


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