mcoppey

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

Linards Ticmanis

On 01/31/2012 03:16 PM, mcoppey wrote:
> 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?

Admittedly I don't know about the //c, but I did the same thing, putting
an American mainboard in a European machine, with a //e.

In the //e you have to switch the video ROM only if you want or need the
non-US characters, such as German umlauts etc. I had to build an adapter
to fit in the larger ROM. Maybe the //e has an 28 pin socket even on the
American board though?

If you want to use the corresponding local keyboard, you'll also have to
switch the keyboard decoder ROM, at least in the //e you do.

I'm not sure whether a PAL IOU works in a NTSC mainboard; I use a
multi-norm TV as output and it can deal with NTSC, so I left the NTSC
IOU in my //e when I put in an American mainboard. Even if you swap the
IOU, the American mainboard will output NTSC-50, not real PAL, so you
can't use it with a PAL-only color monitor. Of course with a monochrome
screen it doesn't matter.

There are list of Apple chip numbers floating around on the web, via
Google you should be able to find out the numbers of the affected chips,
then you can identify them by number on your motherboards. Or you could
follow the traces on the board from the Standard-Dvorak (or US/local)
switch connection; it will lead to the keyboard and video ROMs. The
smaller one is the keyboard ROM.

--
Linards Ticmanis