When the PPU is doing the dummy sprite pattern fetches for "sprite $FF". Does anyone know which, if it is predictable, row of the sprite gets fetched?
The reason I ask is that while it probably doesn't make a huge difference (or at the least, I'm not aware of anything that would care). But it does change what address is read. For example.
In 8x16 sprite mode the possible addresses read are any value from:
depending on if it is the first or second fetch
In 8x8 mode, there are a bunch of possible options as well:
So this may just be an academic excessive, but does anyone know which row is fetched from this "dummy sprite"
The reason I ask is that while it probably doesn't make a huge difference (or at the least, I'm not aware of anything that would care). But it does change what address is read. For example.
In 8x16 sprite mode the possible addresses read are any value from:
Code:
$1FE0 - $1FE7 or
$1FE8 - $1FFF
$1FE8 - $1FFF
depending on if it is the first or second fetch
In 8x8 mode, there are a bunch of possible options as well:
Code:
$0FF0 - $0FF7 or $1FF0 - $1FF7
$0FF8 - $0FFF or $1FF8 - $1FFF
$0FF8 - $0FFF or $1FF8 - $1FFF
So this may just be an academic excessive, but does anyone know which row is fetched from this "dummy sprite"