Old Compaqs have a BIOS on the hard drive. Sp1363.exe will make a boot disk, which will copy the BIOS to your hard drive.
Worked fine with my Presario 900 series (954 CDS) but I think it'll work with any Presario 100-900 series. Maybe others as well?
Couldn't download from Compaq, but I found this site www.compupartner.dk/drivers/Motherboard/Compaq/
It has the following files sp1363.exe sp2373.exe SP2824.EXE sp4701.exe sp5975.exe sp8886.exe