20-10-2022, 08:27 PM
Best to keep it pristine and hook up a 32K SRAM on an expansion board.
It should be pretty easy to do with a single 32K RAM and a decoding GAL.
Piggybacking chips makes it difficult to replace faulty ones and looks messy.
If you want to replace the 4116s with 4164s be aware that 4164 DRAMs don't require the +12V and -5V voltages and that the +5V pin moved to the old +12V pin.
The old +5V pin becomes A7, the old -5V pin becomes NC (No connection)
It should be pretty easy to do with a single 32K RAM and a decoding GAL.
Piggybacking chips makes it difficult to replace faulty ones and looks messy.
If you want to replace the 4116s with 4164s be aware that 4164 DRAMs don't require the +12V and -5V voltages and that the +5V pin moved to the old +12V pin.
The old +5V pin becomes A7, the old -5V pin becomes NC (No connection)