Hi All, I just wanted to say "Thank you" to everyone who helped me fix this classic IBM XT motherboard with the Diagnostic ROM image and the settings for the AWARD POSTcard. Long story short, I replaced a 74LS245 and a faulty DRAM chip and now the board boots fine. Of course half the fun is finding what actually works, what doesn't, what appears to be broken but actually works, what is broken but appears to be working, etc. You know the drill, I am sure. Fixing an old broken 16 bit VGA card which works in an 8 bit ISA slot helped a lot. As did the old style PC/XT style floppy drive controller... So anyway, it's fixed and I booted MS-DOS 5.0 and the Advanced IBM Diagnostics from a 5.25" floppy disk drive. So I think we are there. THANKS! Andrew Lynch PS, BTW the XT Diagnostic ROM image seems to work best when burned into a 2764 EPROM. I tried various other types of EPROM but the 2764 seems to work best. I think IBM did some weird remapping of their custom Mask BIOS ROM...