PDP-11/23 Debugging

Noel Chiappa jnc at mercury.lcs.mit.edu
Thu Nov 20 13:37:44 CST 2014

    > From: tony duell

    > Err, isn't the first question 'Do you have a logic analyser?'

Depends on who you're talking to... :-)

    > From: Ben Sinclair

    > I did find a Sigma brand M8043 equivalent on eBay for a decent price
    > (via a make best offer). Is using non-DEC hardware just adding more
    > variables, or are they generally okay?

There are 3 factors to consider in using non-DEC boards these days, I find.

#1 - Can you get documentation? (In this case, yes. I have some where the
answer is a resounding no, e.g. a Clearpoint DCME/Q4E 4MB PMI memory card.)

#2 - Can you get the cables/etc? I don't know the answer in this case; I will
note that this apparently doe not use the same cable as a DLV11-J - it uses a
40-pin header - _but_ you may be able to plug your DLV11-J cable into it.
There's an page that talks about it a bit:


although note that there seems to be something wrong with the URL for
the image of the board on that page, this works:


and according to that page, you can plug a 10-pin shell into the 40-pin
header. Seems slightly dubious to me, but maybe it'd work!

#3 - How good were the boards when they were new? Reliable, flaky, etc? In
this case, Sigma mostly made pretty good stuff, although I have no experience
with this particular card.

Your call!


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