hi
Seems theres a bug in zsnes (for this game), which results in a weird display of the info panels (race info, and speed/gear etc)
It works perfect in snes9x
thanks
F-1 Grand Prix (J) bug (in 1.42 as well as all wip...)
Moderator: ZSNES Mods
F-1 Grand Prix (J) bug (in 1.42 as well as all wip...)
Last edited by geoslake on Mon Oct 16, 2006 9:13 pm, edited 1 time in total.
Read how to report a bug properly: http://board.zsnes.com/phpBB2/viewtopic.php?t=3821
-
byuu
This bug also affects Sink or Swim. When VIRQ is enabled and fires on a scanline, writing the same VIRQPOS into $4209-a on the same scanline will cause the IRQ to fire again. It is currently blocked by ZSNES, causing the screen skipping.
Example of correct behavior:
VCOUNTER=8, VIRQPOS=9
... run one scanline ...
VCOUNTER=9, -> Fire IRQ #1
... write #$0009 into $4209-a while VCOUNTER still=9 -> Fire IRQ #2
...
Example of ZSNES behavior:
VCOUNTER=8, VIRQPOS=9
... run one scanline ...
VCOUNTER=9, -> Fire IRQ #1
... write #$0009 into $4209-a while VCOUNTER still=9 -> nothing happens
...
It has not been 100% verified if HCLOCK must be >= HIRQPOS when HIRQs are also enabled, but I believe that is the case. Nevertheless, these two games only use VIRQs.
Example of correct behavior:
VCOUNTER=8, VIRQPOS=9
... run one scanline ...
VCOUNTER=9, -> Fire IRQ #1
... write #$0009 into $4209-a while VCOUNTER still=9 -> Fire IRQ #2
...
Example of ZSNES behavior:
VCOUNTER=8, VIRQPOS=9
... run one scanline ...
VCOUNTER=9, -> Fire IRQ #1
... write #$0009 into $4209-a while VCOUNTER still=9 -> nothing happens
...
It has not been 100% verified if HCLOCK must be >= HIRQPOS when HIRQs are also enabled, but I believe that is the case. Nevertheless, these two games only use VIRQs.
