Commodore 128D PAL Computer

I just bought a very nice looking Commodore 128D computer from eBay from a seller in Slovakia, which is a 220V / 50 Hz PAL unit. Before I pulled the trigger on the purchase, I did some research on whether or not you could even run a PAL machine in North America, mainly due to the difference in powerline frequency: 50Hz for PAL vs. 60Hz for NTSC. It's simple enough to use a step-up transformer to convert our 120V AC to 220V AC to satisfy the voltage requirement of the power supply inside the unit, and I successfully did this with a number of 220V SFD-1001's I bought before I converted their power supplies to switch mode units which will run on either power system, are a fraction of the weight and produce a tenth of the heat the stock linear power supplies produce, even when the drive is idle. Unlike SFD drives which only use 12VDC and 5VDC internally, computers like the Commodore 64 and 128 also derive some timing signals from the powerline frequency. Specifically, the CIA chips which hold the C64's "real" time clock, base their timing signals on the frequency of the incoming AC sine wave, so having the wrong frequency coming in will make the clock run faster or slower, depending on which way you are going.

There have been a number of suggestions online such as building a discreet clock signal generator that ignores the power frequency altogether, making the computer run the same way on either frequency. The only real other consideration is the video signal output, which comes from the VIC chip. In order to convert from one system to the other, you have to replace the VIC chip (or VIC-II in the 128) with one from the corresponding power standard, and there's a few changes you need to make on the board as well like changing a timing oscillator crystal and adjusting some traces.

A large part of me is very curious to see how games and particularly demos run on a PAL machine, since probably the vast majority of new software coming out for the 64 is written in Europe on PAL computers.