My friend and i started coding a NES emulator, the cpu is almost ready, so the APU, so i started coding the PPU but i realized something.
The init code http://wiki.nesdev.com/w/index.php/Init_code has this little piece of code:
If the accumulator is always zero how can the BPL go to next line?
Maybe it could be just a stupid question but i couldn't find the answer neither searching in the wiki, neither the forum.
Thanks in advance
The init code http://wiki.nesdev.com/w/index.php/Init_code has this little piece of code:
Code:
@vblankwait1:
bit $2002
bpl @vblankwait1
bit $2002
bpl @vblankwait1
If the accumulator is always zero how can the BPL go to next line?
Maybe it could be just a stupid question but i couldn't find the answer neither searching in the wiki, neither the forum.
Thanks in advance