FixUntilBroken
New Member
Yesterday I started working on restoring a Compaq Portable and I replaced the keyboard foam pads. It had a couple more issues such as a 501 error and a bad B: drive so I opened it up. I also wanted to check the bios revision to see if I could add an XT IDE and I found it had a 100298-005 bios chip dated '84 which according to PCJRs website is rev F. I'm trying to fix an XP machine that I use my Willem eprom programmer on so I can dump the bios. It also had the U35 decoding PROM which is marked with the Texas Instruments logo and the numbers "8428XF 100340-001A TBP18S030N". The computer had banks 2 & 3 populated with 16 64k x 1 chips and I swapped in some 256k x 1 chips to get it to 640k. The 501 error is also manifested as graphical corruption in a couple games I tried such as Night Mission and Rogue. It looks like the MC6845P CRT controller chip is damaged as the plastic packaging has a grey discoloration surrounding the center of the chip so I've ordered a new one to swap in but it won't be here for a while.
