Nivag Swerdna
Veteran Member
I've been occupied elsewhere... what is the current state?
I don't have a dynamic PET, mine is much simpler using static RAM, so I don't have direct experience but one observation is that DRAM will lose a value if it is not refreshed... accessing a DRAM address is effectively a refresh so in the absence of refresh a DRAM will appear to work if you address it frequently enough. Maybe we need to follow through the refresh logic?
PS
A ROM/RAM replacement board doesn't really help in isolating RAM faults since it merely hides them by substitution.
I don't have a dynamic PET, mine is much simpler using static RAM, so I don't have direct experience but one observation is that DRAM will lose a value if it is not refreshed... accessing a DRAM address is effectively a refresh so in the absence of refresh a DRAM will appear to work if you address it frequently enough. Maybe we need to follow through the refresh logic?
PS
A ROM/RAM replacement board doesn't really help in isolating RAM faults since it merely hides them by substitution.