I' am try to back to life an AM700.
After changing capacitors, washing pcb, check for corroded track the unit boot up and enter diagnostic mode. After solve some issue I dropped in a FP RAM error, I have posted a a screenshot in photo album AM700 folder. Anyone could help me to decode this error?
I've never seen one of those before, but TekWiki has a full service manual
for it (http://w140.com/tekwiki/wiki/AM700). I find this pretty
interesting, as this device is from a time when Tek (and others) had pretty
much stopped issuing component-level service manuals for their devices. You
have a copy, I hope?
In the service manual, there's a table with the CPU's memory map, which
claims this about the afflicted range:
0E00 0000 – 0EXX XXXX I/O Processor Shared Memory/Registers
I took a quick look at the service manual, and my guess is that this'd be
referring to the memory that's shared with the front-panel processor. In
the Theory of Operation it says "The address bus to the front panel
RAM is buffered by bidirectional data buffers on diagram 7", so maybe those
could be at fault?
The processor's data bus seems to be pulled high, so if you have a bad
output driver, you'd get a stuck-hi bit.
On Tue, Jun 9, 2020 at 3:11 PM Juri Ghisio via groups.io <yurighisio=