Hi, according to the Apple II reference manual, the Europlus (50 Hz) model has a different main crystal frequency than the standard NTSC model. I have a Europlus that I want to convert to NTSC, in order to get color output (Europlus video is monochrome if you don't have a PAL video card, which I don't).
I have reverted the X- and O-pad changes, but I'm not sure what frequency the current main crystal is. I think it is labeled something like "197-000"...
So my questions are:
1) what frequency is the main crystal in the Europlus, and in the standard NTSC model?
2) how do I know the frequency of my current crystal?
3) are modern CRT monitors capable of displaying both PAL and NTSC, or do I need to get a NTSC-only monitor?