And the winner is ...

r7683 /src/mame/ (machine/snes.c includes/snes.h): [SNES]: Moved the i/o update status inside a timer, this fixes F-1 Grand Prix Part 2 booting

For whatever reason, the scanline timer was jumping from 240 to 257 (!), hence it wasn't updating the i/o status (that happens on line 242 in this case). I've forced that to happen on a separate timer.

*Does I/O update happens when the NMI is disabled?

EDIT: notice that this update requires a clean recompile (or a forced driver/snes.c compile), otherwise inputs doesn't work at all.

Last edited by Kale; 04/03/10 03:47 PM.