Help w/DEC H742 +15V...
ard at p850ug1.demon.co.uk
Tue Apr 14 12:21:42 CDT 2009
> Thanks -- just tried this, and I still get the same behavior from the
> CPU. ACLO and DCLO are now pulled high. Well, this is going to be a
And waht behaviour is that? Can you do anything from the front panel, for
> fun project :). Guess I need to start debugging the CPU, any
> suggestions on where to start? (Anyone have a Unibus extender card?)
I haev most of the DEC extender cards (single, dual, quad, hex), but that's
not a lot of use to you :-)
I trick I commonly use if I don't have the right extender card is to pull
the board I want to work on and solder lengths of wire to useful points
on that PCB. Then put the board back in place, make sure the wires aren't
shorting to anything and then power up. I can then connect my test gear
to the free ends of the wires.
It's slower than using an extender card, of course, but typically I only
need 2 or thre 'goes' (pull board, solder on half a dozen wires, put it
back, test) to find the fault.
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