IIc 9" monitor with American motherboard

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IIc 9" monitor with American motherboard

I just swapped the 02-motherboard for my European IIc to an American
03-motherboard. Is it possible that this affects the output to the
monochrome 9" monitor? With the old 02-European motherboard the view
was perfectly centered on the screen. With the American 03
motherboard, I can't get the output centered, it moves to the left and
some lines (4) downwards. Finetuning with the rear knobs doesn't
change anything. Am I correct that apart from swapping character
generator and keyboard decoder ROM, I also have to swap the US 60 Hz
IOU chip for the European 50 Hz version and the Video ROM? (the 28pin
2764 equivalent instead of the 2732 equivalent on the US model). And
where is this video rom situated on both motherboards?
mcoppey

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Re: IIc 9" monitor with American motherboard

all viewed effects can be reduced to one single point: the difference between 50 Hz and 60 Hz and the difference in the basic timing of PAL and NTSC..
The 50 hz or 60 Hz affect the timing generation by indirect effects and generate a slight shift in the base of all related parts of the videosignal so the main point to solve the issue is to sweep those parts that are related to the difference between videotiming of the generated PAL or NTSC coding ( i.e. the true difference between US version and German Version of the IIc ) - so the change of the IOU chip and the The Video-ROM should solve the problems.
Video ROM in the US-Version is labeled: 341-0265-A

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