On 04/15/2018 05:08 PM, allison via cctalk wrote: > On 04/15/2018 10:25 AM, David Griffith via cctalk wrote: >> >> I'm pondering upgrading the CPU of a Pacccomm Tiny-2 Mk2 radio packet >> controller from a 6Mhz Z80 processor and SIO to 10Mhz parts. My >> problem is that the parts already in it appear to be NMOS. The family >> is still being made by Zilog, but for 10Mhz parts, CMOS is all they >> have. Can I just drop in CMOS, change out the crystal/oscillator and >> have things work as expected? >> > No, and why? > > Changing to CMOS can cut power drain. However speeding up clocks can > make the packet controller > broken even if it runs! If you keep the 6mhz clock all will be fine.
Quite correct, Allison. I confined my answer to "Can I drop a CMOS Z80 into an NMOS Z80 socket?" And in particular, why not run the 10MHz part at the original 4MHz or whatever? A 10MHz part doesn't mean that it has to run at 10MHz. As to the rest of the question, I confess that I was blind. --Chuck