Hi,
I resurrected an Soltek SL56D5. New (used) CPU-socket (pita to remove), caps, reflow this and that.
It's got 512kB cache, and one footprint on the PCB is empty.
The present cache-chip is the ISSI IS61SP6464-100pq, 64k x 64 -> 512kB.
The epox VP3 got dismantled for parts, 5V has gone in places it shouldn't. And there lies a Winbond W25P240AF-6 - also 64k x 64 -> 512kB.
Is the winbond pin-compatible and can it be paired with the ISSI, or am I better of getting another ISSI-chip?
The winbond is 66/75MHz, while the ISSI is 100/117MHz. This can be an issue.
Edit: Stupid, sleep-deprived me. One is QFP100, the other QFP128 ...

Furthermore, is a larger TAG needed? I will have to get back to you with info on the current tag. Surely, some jumpers need to be set - any idea of these?