Knut Roll-Lund writes:
I'm considering to buy an RGB/80-columns card for my IIe.
Will a card from USA would work for me in my European Apple IIe?
I think of the frequencies... My IIe is for 50Hz power and outputs a
50Hz signal for video. Americans use 60Hz for power and video. So would
an RGB card from US output 60Hz video in my machine which would be
incompatible with a European monitor?
If this is a problem, would it be possible to modify the card to 50Hz
(by changing a crystal or something like that)?
The IOU chip in the IIe is responsible for the 50/60Hz video (there are
two different versions of this chip for the IIe with the 50Hz version adding
another 50 black lines at the end of the screen). The main crystal is also
slightly different (14.318 vs 14.25 MHz).
The RGB card will just use whatever frequency the motherboard scans the RAM
at. I have a PAL IIe with a 60Hz IOU chip because I have a Sequential Systems
Meg80z card which could not handle the different refresh pattern and would
not display the first 7 pixels in DHR or 80 column modes.
You are unlikely to have the same problem - I would buy it and try it.