I can boot my 10 MHz AT clone with the IBM Version 1 (01/10/84) ROM just fine, but the Version 3 (11/15/85) beeps out a system board error (long-short). I seem to recall that the Version 3 BIOS checked for an 8MHz CPU clock and complained if it was anythng else. I know that the Ver. 2 BIOS checked for a 6MHz clock. Is my memory correct--and does anyone know of a patch? I could do a little digging into the POST code, but I'd rather not duplicate someone else's effort. Cheers, Chuck