From: Mike Naberezny (mike_at_naberezny.com)
Date: 2008-09-18 19:03:54
Marko Mäkelä wrote: > And some guys successfully replaced some PLA with an EPROM; > a small wonder, because EPROMs have much longer access time than the > signal propagation time in the PLA. My 8296D had a bad PLA in UE5. I recently replaced it with an EPROM using a small adapter: http://mikenaberezny.com/projects/pla-eprom/ The EPROM that I used is an AM27C512-45 (45ns) from AMD. I compared the propagation delay table on its datasheet against the datasheet for the Signetics 82S100. Chip Enable to Output on the 82S100 is typically 15ns, max 40ns. The AM27C512-45 datasheet only gives max, 45ns. Input to Output on the 82S100 is typically 35ns, max 80ns. Address to Output on the AM27C512-45 datasheet only gives max, 45ns. Of course, I do agree that any old EPROM is probably not suitable. I think the AM27C512-45 is a viable replacement based on this data. The computer works well with it installed. Regards, Mike -- Mike Naberezny (firstname.lastname@example.org) http://6502.org Message was sent through the cbm-hackers mailing list
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