Hey guys! I'm still working on my hardware implementation of the NES (FPGA-based). At the moment I'm trying to figure out a weird joypad bug that I'm only experiencing with Super Mario Bros. For whatever reason the game won't recognize any of my button presses. I can't even start the game with the Start button. The game runs through it's short little demo just fine but I can't do a thing.
I've tried running 22 other games with my hardware (only ones that don't use any mapper since I have yet to implement any mappers) and none of them have this issue. Is there something special about how Super Mario Bros reads data from the joypads that I don't know about? I mean, I don't see how you could make the process any different than:
write 1 to $4016
write 0 to $4016
read from $4016 (A)
read from $4016 (B)
... etc
Are there some games that do weird things with the joypads that I don't know about?
ANY ideas whatsoever might help me with this. I've been working on this for a _while_ now and I've just about given up!
I've tried running 22 other games with my hardware (only ones that don't use any mapper since I have yet to implement any mappers) and none of them have this issue. Is there something special about how Super Mario Bros reads data from the joypads that I don't know about? I mean, I don't see how you could make the process any different than:
write 1 to $4016
write 0 to $4016
read from $4016 (A)
read from $4016 (B)
... etc
Are there some games that do weird things with the joypads that I don't know about?
ANY ideas whatsoever might help me with this. I've been working on this for a _while_ now and I've just about given up!