I've been using a 4 MHz 6502B for my SBC and was considering upgrading to a 65C02 later on.

the problem I have now seems to be voltage. I have just blown out my second 6502B, the 6522 may or may not be ok. The emulator reads a voltage of 5.2 volts there.

How tolerant are the 65C02 and 65C22 to overvoltage? If they seem ok, I will make the switch and pronto.

Dang, and just got the matrix switching and 3 seconds later...dead ....

_________________
"My biggest dream in life? Building black plywood Habitrails"

The absolute max in the spec.s is usually 7V. I suppose some parts will go well beyond that without blowing, but I've never had any reason to find out. Any semi-well behaved 5V supply should be perfectly safe. If you're concerned about a spike at turn-on, you can put a 5-watt 5.6V or 6V zener diode across the supply. (Make sure the anode goes to ground.)

The only time I may have blown any 65-family part would have been from the time I let a metal tool roll under the wire-wrapped board while it was powered up and short pins together. I didn't even bother to find out what went. I just replaced all the ICs and was up again in a couple of minutes. I've gotten a couple of Rockwell 65c22's awfully hot from a latch-up situation possibly from powerline spikes on a printer connected with a long cable and powered up from a different AC circuit, but no damage was done. It hasn't happened in many years, and I think the WDC parts are more resistant to that latch-up condition anyway.

The 6502B also tends to run hot since I am pushing it at the full 4 MHz, so its prolly in the best interest to swtich over anyways.

The power supply I am using for test is an arcade switching power supply. Its been old faithful on my test rig. When the board gets into the pinball, then it has to deasl with the pinball power supply.

Methinks me needs to do some purchasin out here......

_________________
"My biggest dream in life? Building black plywood Habitrails"

The supply voltage range will be specified in the datasheet somewhere. It's usually 5V +/- 10%: you can trust the specified parameters (bus timing and so on) for any supply voltage from 4.5V to 5.5V. CMOS parts will probably be a lot more tolerant on the low end.

The NMOS ones are tough. I once had the power connected backwards (a mistake, and not mine) to a board containing a 6502, a couple of 6522s, a 27256, 62256, and a handful of HC parts. It was a few seconds before we realised that the power LED [i]really[/i] should be on. Unplug, swap wires, plug back in. Worked fine.

Agreed they are tough little buggers. On the arcade games I work on, their failure rate is super low compared to 8080s, Z80s and 68000s. Buyt having two CPUs fail during bench testing, methinks its time for the upgrade anyways....

_________________
"My biggest dream in life? Building black plywood Habitrails"