OP4@PSUVMA.BITNET (09/06/86)
Hi all!
I seem to be having some trouble with the Z80 cartridge I purchased recently
for my C-64. It doesn't want to boot up on my machine. I did find some
information that the Z80 will not work on the later models of the C-64,
namely, the 3rd and 4th models.
Does anybody out there have any information on how to make the Z80 work on
these later models? It would be a great help.
Thanks in advance,
Bill Myers
Penn State/York
OP4@PSUVMA.BITNET
daveh@cbmvax.cbm.UUCP (Dave Haynie) (09/09/86)
> Xref: cbmvax net.micro.cbm:455 net.micro.cpm:598 > > Hi all! > I seem to be having some trouble with the Z80 cartridge I purchased recently > for my C-64. It doesn't want to boot up on my machine. I did find some > information that the Z80 will not work on the later models of the C-64, > namely, the 3rd and 4th models. > Does anybody out there have any information on how to make the Z80 work on > these later models? It would be a great help. > > Thanks in advance, > > Bill Myers > Penn State/York > OP4@PSUVMA.BITNET > You've found a classic problem , which is waht resulted in the Z-80 card being discontinued. The original card worked fine on the C64 that it was designed for. That machine used a Revision 5 (as I recall) VIC chip. Later on, the VIC was revised to cure a problem it had with sparkling characters. That impacted on total system timing, but no effort was made to fix the CP/M card. The result is that if you have a system with a REV 7 or 8 VIC, you have less than about 50% chance of the CP/M card working. -- /\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\ Dave Haynie {caip,ihnp4,allegra,seismo}!cbmvax!daveh "I gained nothing at all from Supreme Enlightenment, and for that very reason it is called Supreme Enlightenment." -Gotama Buddha These opinions are my own, though for a small fee they be yours too. \/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/