cg@myrias.UUCP (Chris Gray) (08/06/86)
Using video RAMs can certainly cut down on bus contention, but can they provide the fancy features that the Amiga has? I don't know the details of them, but I thought that they just provided a one-bit output through which a selected row of the RAM could be shifted out. Thus, the length of the row is controlled by the RAM chip itself (or are there parameters you can give the chip? Can you gang them to make rows longer than the chip supports?) Also, how do things like scrollable playfields, variable resolution, variable size playfields, etc. fit in? I suspect a solution using video RAMs would be quite complicated. The Atari could do it, since they just have three fixed- format screen types (lo-res, med-res and hi-res (monochrome)), and none of the playfield stuff. Sprites wouldn't affect anything, but would still be stealing a little bit of the bus. Having multiple resolutions/depths on the CRT at one time, done by sliding "screen"s up and down, should be fun. Chris Gray (...!ihnp4!alberta!myrias!cg)