[Coco] Using a NTSC Coco in the UK - my findings

[Torsten Dittel]

> A few years ago I was so lucky to snatch an Australian Coco 3 from eBay that
> readily could be connected in Europe to both 240V power and PAL televisions
> (though I still have the CM-8 from back then).

Yeah, I prefer the Aussie version too. The PAL Composite Video signal
ist not the (poor) NTSC signal generated by the GIME itself (this GIME
pin is not connected in PAL machines) but it's mixed on an additional
daughterboard directly from the RGB signal (software works even if only
made for the RGB palette). The Aussie CoCo3 has a modified BASIC ROM
which inits the GIME to 50Hz operation. Since most PAL monitors and TVs
are able to display PAL with 60Hz (although this is outside the PAL
specs) even software poking the GIME back to 60Hz works fine. Shipping
from Australia to UK should be quite cheap anyway.

> Recently however, when I fired it up again it now only get garbage on the
> screen to my great dismay. I know not yet how to solve this problem, but it
> is pretty tragic really... :-(

I had the same probs with one shipped from Australia and after pressing
gently(!) on the GIME it worked again. Looks like a contact problem of
any of the socketed stuff (in your case it's more likely the 512K
board).

Regards,
Torsten