Anomie's Register Doc
@Dreamcast
Published in
SNES
· 7 months ago
... he subscreen pixel at the left edge of the screen is unknown. This is really important with color subtraction: normally, if you have a block of cyan (#00ffff) on main and a block of magenta (#ff00ff) on sub, subtraction would give a block of green. Hires math will give you a block of alternating green and red, which will probably appear yellow on your TV. If you've set $2131 bit 6 and this block is sitting alone in the middle of the backdrop, you'll have a bright line at the left edge where the fixed color was subtracted from the subscreen pixel and no 1/2 was applied (because the previous main pixel had the fixed color subtracted and no ...
