14 Apr
2009
14 Apr
'09
5:21 p.m.
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
example?
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.
=tony