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About F-1 race
Posted: Thu Jan 09, 2014 9:56 am
by Boolean
Hi, everyone.
A strange situation occurred when my emulator run F-1 race.
Screen flashes once, then the lights change color.
This behavior was repeated four times(because 4 lights) before the car rush.
Did this behavior occured because of no APU implementation?
Re: About F-1 race
Posted: Thu Jan 09, 2014 11:51 am
by WedNESday
Boolean wrote:Did this behavior occured because of no APU implementation?
Certainly not.
Re: About F-1 race
Posted: Thu Jan 09, 2014 6:54 pm
by Boolean
WedNESday wrote:Boolean wrote:Did this behavior occured because of no APU implementation?
Certainly not.
Thank you.
Re: About F-1 race
Posted: Thu Jan 09, 2014 7:14 pm
by Zepper
Notice that each time the grid lights change (and plays a buzz sound), the screen glitches. It may be related with APU, yes.
Re: About F-1 race
Posted: Thu Jan 09, 2014 7:54 pm
by cpow
Zepper wrote:Notice that each time the grid lights change (and plays a buzz sound), the screen glitches. It may be related with APU, yes.
Even if it is, the question to begin with is loaded with too many freaking variables.
Re: About F-1 race
Posted: Thu Jan 09, 2014 8:07 pm
by Zepper
The game writes $C0 to $4017, disabling frame IRQs, plus writes $00 to $4001/4005 (sweep off) and to $4011, plus $0F to $4015.
RAM at $01Cx are mirrors of the sound registers, like $01C0=$4000,$01C1=$4001,$01C2=$4002 etc.
Interesting, the game does a couple of timed writes to $4017 (always $C0).
Re: About F-1 race
Posted: Fri Jan 10, 2014 3:40 am
by WedNESday
Zepper wrote:Notice that each time the grid lights change (and plays a buzz sound), the screen glitches. It may be related with APU, yes.
When the APU is enabled/disabled on WedNESday there is no glitching. Therefore something is wrong with his emulator. Obviously it must be to do with sound then.
Re: About F-1 race
Posted: Fri Jan 10, 2014 6:11 am
by thefox
WedNESday wrote:Zepper wrote:Notice that each time the grid lights change (and plays a buzz sound), the screen glitches. It may be related with APU, yes.
When the APU is enabled/disabled on WedNESday there is no glitching. Therefore something is wrong with his emulator. Obviously it must be to do with sound then.
Why didn't you mention this right off the bat?
Re: About F-1 race
Posted: Fri Jan 10, 2014 8:02 am
by WedNESday
Sorry thefox. Just to clarify that WedNESday runs it just fine.
What I mean is no APU emulation means that it cannot be to do with the APU as I remember running this on WedNESday with NO APU emulation and it was error free. Obviously, its a timing issue where the NES updates the PPU address but outside of VBLANK. Or it could be a Sprite 0 problem.
Boolean how is the emulator on blargg's Sprite 0 tests?
Re: About F-1 race
Posted: Fri Jan 10, 2014 10:22 am
by Boolean
WedNESday wrote:Sorry thefox. Just to clarify that WedNESday runs it just fine.
What I mean is no APU emulation means that it cannot be to do with the APU as I remember running this on WedNESday with NO APU emulation and it was error free. Obviously, its a timing issue where the NES updates the PPU address but outside of VBLANK. Or it could be a Sprite 0 problem.
Boolean how is the emulator on blargg's Sprite 0 tests?
blargg's sprite 0 hit tests(sprite_hit_tests_2005.10.05) and ppu tests(blargg_ppu_tests_2005.09.15b) almost pass. But there are some errors.
VirtuaNES has the same result.
Error code:
2) Should miss when entirely in left-edge clipping
2) Hit time shouldn't be based on pixels under left clip
6) Palette read should also read VRAM into read buffer