Ok, found the jumpers for the DL11 in the schematics section on bitsavers. I
have two M7800's, one is set for 777560 and one is set for 776500.
I'm assuming that when a card is jumpered so (the high bits are constant
anyways), that it appears exactly at that address no matter how much memory
is installed in the machine (ie. it doesn't move around based on maxmem).
Anytime I exam 777560 I get an address error. If I exam 776500, I get a 200,
but anytime I store a value and read it back, there's all zero's in the data
register.
Methinks the problem wasn't memory, but something amiss in the cpu section.
Bummer as I have no spare cpu cards. But I guess at this point I still don't
know if it's a unibus problem or a cpu problem.
Something else I noticed is the terminator cards in front and back as well
as the cpu backplan to MF11-L had what I would think is a lot of "up down
wiggle" in them. I'm quite sure they are seated completely, but I can turn
them up or down more than I would think one should be able to. Is that
common?
Hopefully sage listemembers can offer some advice as to where to go next :)
Jay West