Indivision AGA sits on top of the Lisa chip, so a "riser" would have to have an empty PLCC84 chip to make connection with the flickerfixer. In addition to such a non-existent part (at least not to my knowledge), signal length would harm signal quality. I would have done that long ago, especially with so many A4000D/CD32 versions in stock, that you're hopefully buying this xmas season :-)
Jens
Is it true there will be an Indivision AGA (A1200) MKII ? If so any word on the improvements. I want to buy one...
