How I Solved the DC VA0 JAP Black Screen Issue in Four Games!

[CrisMod]

(02.11.2023 21:52)Freudi93 писал(а):  Yes this is axectly the Problem i have. Also dave mirra freestyle bmx
Quake 3
Railroad Tycoon II - Gold Edition
Sega Gt
Toy Racer
Toy Commander

Have same Problem

Hello Freudi93,

I've tested the games you listed:

1. Dave Mirra Freestyle BMX
2. Quake 3 Arena
3. Railroad Tycoon II - Gold Edition
4. Re-Volt
5. Sega GT
6. Toy Commander
7. Toy Racer

I conducted numerous tests using Loaders that support CDDA, and I even tried the physical disc as an additional test. Based on the tests I performed, I can confirm that when CDDA is activated (in those listed games), in-game music exhibits crackling while all other environmental and graphical sound effects work well.

If CDDA is deactivated, you can hear all the graphical, environmental, and menu selection sound effects but not the background music (or a part of it). I might have figured out why this happens, and I'll try to explain it in simple terms (here, @SWAT may either confirm or refute this theory).

This issue appears to be related to how the game handles music, which is loaded kind of separately from other in-game sound effects and environmental audio. When CDDA is active, will force to load the background music but isn't entirely loaded into RAM with the game and rather fetches data continuously, communicating with the SSD/CF/HDD, and so on. In fact, I observed that the background music, being somewhat separate from the game's effects, in certain games that require more RAM and almost fill up the entire RAM space, there isn't enough room to accommodate the Loader along with all the game's assets. With the physical disc, everything works normally because it utilizes the hardware without "emulating" the GDROM.

Therefore, it seems that with CDDA active, the background music is constantly loaded and unloaded in small blocks (as the rest of the RAM is occupied by DS Loader, preloaded scene textures and so on) within a limited RAM space. This is because some games consume nearly all available RAM, and in terms of development, I believe that @SWAT faces a significant challenge. What he has achieved so far in managing all of this within hardware with precise resources (for certain games) is truly outstanding.

In games that don't consume all available RAM, the background music with CDDA enabled sounds fine. However, in cases where a game has heavier 3D graphics and consumes more RAM, there's less space available for CDDA to load additional background music that is separate from the game. Consequently, when there's limited space, the Loader must constantly load and unload data into RAM, fetching data continuously from the IDE, which leads to those annoying audio crackles.

It seems reminiscent of when, a few years ago, I created Sonic 64 for Dreamcast using the Mario 64 image, where the Nintendo 64 textures consumed most of the RAM. To overcome this, I had to consider a possible RAM upgrade, increasing it from 16 to 32MB.