> > > > This is what Simon proposed some time ago (that is, adding a souped up CPU > > and a chunk of memory, neither of which the ASIC knows anything about, and > > some kind of linkage which allows the new CPU to write to the Sam's memory > > if it wants (which it has to do in order to display a picture)). > > > > You could be really cock-eyed and have split the memory banks - let the > ASIC deal with the lower 256K and the new processor deal with the top > 256K as fast as it likes. Ok, this means that any video data will have > to be in the lower 256K. Just think of all that refresh-logic, bank > switching circuitry that you'd have to design..... >
BEat you to it :) 4 banks, 128k in size. You can choose which bother to update the internal memory, and which just run along at full pelt :) Simon
