I recently acquired a Lisa 2/5 as a project. PSU fixed, corrosion repaired. It has 2x 512K RAM cards in it.
Getting an error 70. I have narrowed it down to 1 card. The bad card is in slot MEM 1, MEM 2 left empty.
Enter service mode, Read memory location $186 gives 0000 0000 0000 0004. Cool! From what I read, that means the chip at Row E, Column 20 is bad.
Replaced the HM4864P-2 with a now socketed Fairchild MB8264-20, which I believe to be compatible.
Still get error 70!
Memory location $186 now gives 0000 0000 0000 0404
So it appears that not only did the RAM I replace still not work, but now i have a new bad bit on column 3 row E?
Thoughts?
Getting an error 70. I have narrowed it down to 1 card. The bad card is in slot MEM 1, MEM 2 left empty.
Enter service mode, Read memory location $186 gives 0000 0000 0000 0004. Cool! From what I read, that means the chip at Row E, Column 20 is bad.
Replaced the HM4864P-2 with a now socketed Fairchild MB8264-20, which I believe to be compatible.
Still get error 70!
Memory location $186 now gives 0000 0000 0000 0404
So it appears that not only did the RAM I replace still not work, but now i have a new bad bit on column 3 row E?
Thoughts?