Motor Toon Grand Prix (Japan) (OG 1994 Release): Some audio effects replaced with hissing after some gameplay

[thepieddragon]

Problem: On the original release of Motor Toon Grand Prix on the PSX, some audio effects seem to corrupt into a static-y hiss after playing the game for a few minutes, and the corruption gradually gets worse, soon affecting the music. Rarely, the game crashes.

Reproduce: Play for more than a couple minutes. Most consistantly seems to happen around the s-bends around the dinner plates and wine glasses on the Gulliver House track.

Workaround: None that I am aware of.

MiSTER Hardware: As the pre-configured bundle with the aluminium armor from MIsterAddons, with the IO Direct board and 2 modules of SDRAM.

Core Version: Stable v240922 , Unstable v240830, 2xCPU v240922

MiSTER Version: Stable v240912

Game Formats: Bin/Cue and CHD. Rev 1 exhibits the same issues.

Other Info: I theorized it might have something to do with the dual ram setup. Unfortunately, turning off the second module didn't seem to fix the issue. This also occours regardless of storage device, or video out.

Edit: Just for the sake of thoroughness, I have tested to see if this happens on real hardware (using a PS2 5000x). As expected, it does not.

[PowerDuckSamurai]

Problem: On the original release of Motor Toon Grand Prix on the PSX, some audio effects seem to corrupt into a static-y hiss after playing the game for a few minutes, and the corruption gradually gets worse, soon affecting the music.

There was the same problem on DuckStation. Stenzek fixed it in this commit: https://github.com/stenzek/duckstation/commit/f9f9447013af71920a1826901f50e7d09505d8a7

Rarely, the game crashes.

This problem was on DuckStation too. The following tweaks fixed this problem on DuckStation:

• ForceInterpreter # Fixes crash in pause screen and random hang on the 2nd track.
• dmaMaxSliceTicks: 400 # Fixes random hang on the 3rd track.
• dmaHaltTicks: 155 # Fixes random hang on the 3rd track.

[RobertPeip]

Thanks for finding the first commit! This should be relativly simple to also fix in the core: in this line: https://github.com/MiSTer-devel/PSX_MiSTer/blob/main/rtl/spu.vhd#L1784 it should be if (loopRepeat = '0' and NOISEMODE(index) = '0') then

If anyone wants to build a version with this and try it, that would be great.

The second one isn't really a fix, it's just using different timing models. The core fulfills most DMA timings compared to the hardware, but of course there can always be some edge case. In any case: the core has nothing comparable to these so I can't do much about it using the fix in duckstation. My first try would be to use turbo low and see if the issue is gone.

[Kuba-J]

Hi @thepieddragon , please test this core with a fix

PSX_20241020.zip (unzip before use )

Problem: On the original release of Motor Toon Grand Prix on the PSX, some audio effects seem to corrupt into a static-y hiss after playing the game for a few minutes, and the corruption gradually gets worse, soon affecting the music. Rarely, the game crashes.

Reproduce: Play for more than a couple minutes. Most consistantly seems to happen around the s-bends around the dinner plates and wine glasses on the Gulliver House track.

Workaround: None that I am aware of.

MiSTER Hardware: As the pre-configured bundle with the aluminium armor from MIsterAddons, with the IO Direct board and 2 modules of SDRAM.

Core Version: Stable v240922 , Unstable v240830, 2xCPU v240922

MiSTER Version: Stable v240912

Game Formats: Bin/Cue and CHD. Rev 1 exhibits the same issues.

Other Info: I theorized it might have something to do with the dual ram setup. Unfortunately, turning off the second module didn't seem to fix the issue. This also occours regardless of storage device, or video out.

Edit: Just for the sake of thoroughness, I have tested to see if this happens on real hardware (using a PS2 5000x). As expected, it does not.

[thepieddragon]

Hi @thepieddragon , please test this core with a fix

PSX_20241020.zip (unzip before use )

Played through the gran prix to credits and did not encounter the initial sound issue, nor any other new issues. Used the Rev 1 version of the CHD to test over composite video.

[Kuba-J]

Hi @thepieddragon , please test this core with a fix PSX_20241020.zip (unzip before use )

Played through the gran prix to credits and did not encounter the initial sound issue, nor any other new issues. Used the Rev 1 version of the CHD to test over composite video.

Great! thanks for testing