Is there any advantage to having diagonal mirroring?
That is:
AB
BA
rather than the traditional horizontal/vertical mirroring
After looking it over, it looks like it would allow nearly flawless 4-way scrolling. You'd still have tile/palette glitches in the corners of the screen, but at least you could have the left 8 pixels of the screen unmasked, and you'd have minimal scrolling artifacts since the absolute top and bottom rows of tiles are offscreen on most NTSC televisions anyway.
However, given that I can't think of any game that uses this type of mirroring, it must not have been a good idea.
Edit: Son of a bitch, I just saw that this was mentioned in the wiki. None the less, that means at least two people have come to the same conclusion. I'd like to test this out somehow (and maybe even use it), but do any other non MMC5 boards allow this type of mirroring?
That is:
AB
BA
rather than the traditional horizontal/vertical mirroring
After looking it over, it looks like it would allow nearly flawless 4-way scrolling. You'd still have tile/palette glitches in the corners of the screen, but at least you could have the left 8 pixels of the screen unmasked, and you'd have minimal scrolling artifacts since the absolute top and bottom rows of tiles are offscreen on most NTSC televisions anyway.
However, given that I can't think of any game that uses this type of mirroring, it must not have been a good idea.
Edit: Son of a bitch, I just saw that this was mentioned in the wiki. None the less, that means at least two people have come to the same conclusion. I'd like to test this out somehow (and maybe even use it), but do any other non MMC5 boards allow this type of mirroring?