First post, by Durandal
Hey guys, I've got an IBM PS/55 Type 5551-T1B that I recently restored and I'd like to upgrade it to a 486 of some kind.
It has a 386DX-20 CPU so I was thinking about putting a Cyrix 486DRX2 66MHz in it, but will it be able to reach the full 66MHz or will it only run at 40MHz? There's a 40MHz crystal on the motherboard labeled OSC.
It also only has 1920KB RAM so I'd like to find some more RAM for it too if possible, the RAM module part number is P/N 65X1211 and it uses IBM 89X8922 chips. I have no idea if it's non-parity or what. The little RAM expansion board that slots into the front of the main motherboard has 2 memory slots that say 2 - 4MB under each one, so 10MB may be the maximum for this machine. I live in Australia where RAM like this is hard to find, so I'd like to make sure whatever I'm ordering from overseas will actually work before I end up spending $30 on 2 month postage.