View Full Version : IC voltage compatibility between different models of Commodore 64

March 24th, 2010, 07:23 AM
I read the wikipedia article on C64 that claims the original "breadbox" model motherboard and C64C motherboard run at different voltages (12V vs. 9V). My current PAL C64 is built from a breadbox model motherboard (Rev.A I think) that had a broken VIC-II chip and worn out keyboard, and a VIC-II chip from a C64C that had a faulty serial port but working keyboard and VIC-II. I built it into the C64C case as it's easier on the wrists when programming.

I believe I've always used the old PSU (as per motherboard), but never experienced any problems with it (though I rarely use the machine these days). Would the voltage difference damage the working VIC-II chip I got from the C64C? As replacement chips get more expensive, preserving the machine in working condition is always on top of my mind.

March 25th, 2010, 07:16 AM
It's actually the SID chip which comes in 9 or 12V versions. The 64 itself still runs from the same power supply and voltages are converted internally for the specific SID installed.