First post, by Kubik
Folks,
as far as I know (the information is floating around for years), it's possible to use 256kx1 chips in all banks of PC-XT mainboard, and after adding 74LS158 to the empty socket U84 and replacing PROM at U44 with a GAL, it's possible to have RAM mapped to UMB. I have seen the equations for the GAL, but I'd prefer to have working and tested JEDEC file for the GAL, as I don't want to spend time experimenting with all those variants of equations I've seen.
Did someone tried that already and can share the JEDEC file?
THanks 1E6!