Den Sun, 25 Mar 2018 15:52:57 +0200 skrev Michał Pleban <lists@michau.name>: > Hello! > > As some of you are already aware, Ruud has started working on the 8088 > card replica for CBM-II computers. With his permission, I put the > initial version of the card online: > > https://github.com/MichalPleban/cbm2-8088-card > > The card has been tested and works. As a bonus, I added my PC > emulation layer and PC-DOS 3.2 boot files in the card EPROM, so it > can boot almost instantly (after the 6509 code has been loaded from > disk, that is). Excellent! > Our next goal is to replace the 6565 chip with a 8255, so that the > card could be make with standard, easy to obtain parts. Btw the original schematics (CBM_8088_CPU_co-processor_schematic.pdf) is hard to read. Just to make sure, is it indeed an 6525? All pin numbers / signals match a 6525 while the schematics says "6523" which seems like a bad copy. If you are anyway going to change the construction, maybe you should consider some dual port ram? Although probably both more expensive and harder to get, it would be far nicer and probably faster too. (In the long run, IMHO it would be best to make a replica B motherboard with faster RAM and 8088 synced to the 6509 signals in a way that makes it possible for both processors to access ram pseudo simultaneously. Some time in a distant future...) -- (\_/) Copy the bunny to your mails to help (O.o) him achieve world domination. (> <) Come join the dark side. /_|_\ We have cookies.Received on 2018-03-26 03:00:02
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