I think you can find some good (and somehow complete) technical information about it on Spritesmind, but you will have to dig a bit to find it i guess (can't find it easily right now).byuu wrote: If only someone would document that beyond the fact that it exists ... I'd love to emulate it =(
Haha, good point you made here Well honestly i think it's still quite difficult to argue the opposite but indeed we can agree or disagree.I mean, apparently there is as we're having it, but ... we can agree to disagree, I suppose.
I should have been more specific: outside the HDMA channels.Don't tell that to the -nearly every game in the library- that used HDMA and per-scanline IRQs to do exactly that ... :/
They are here for that but still, if you don't properly time your code and your VRAM writes goes a bit outside the VBlank period, bang ! On the MD, nothing wrong happen... you just lost a bit of time.
To be honest that happen on many old systems and probably on the SNES as well. Still if you access invalid memory area mean you probably have something really wrong in your code !And how easy it is to hard-lock the memory controller.
Except it works in 256px instead of 320px but Indeed it can (almost) mimic the classical Megadrive mode 5.Mode 2 on Super NES is essentially equivalent to native mode on the Genesis.
The point is that Mode 1, Mode 2 and Mode 7 represents about 95% of use case, other modes are almost useless and make everything much more complicated for nothing.
Not only... you can also do fast 5/6 consecutive word writes per scanline without stalling the CPU which is very useful to not waste cpu time on raster effect for instance. You can also do code interlacing to improve VRAM upload capability but that is edge usable i guessWhich I would find most useful for tile data decompression from ROM to VRAM.