DreamShell 100% Compatibility - Possible?

[SWAT]

The problem not in reading speed in general )) It's more than enough. Only on SD this is a problem, additional problem.
The stream of stereo PCM alternates channels every sector on CD. But DC AICA can't play manually this stream buffer, we need split to separate channels, and for it I writed code on ASM in ISO Loader, for using SH4 optimizations. At splitting we need temporary buffer, before send it to AICA memory for playing, and it uses DMA too, but it's another DMA, and it used with SD too.
For real CDDA uses I2C bus for transfer PCM stream from CD and it directly played by AICA from special input, it's not uses AICA channels and memory in general, sound mixed inside a chip and not uses any other resources. That is why it's difficult to emulate CDDA playback, since we have to use additional resources that were not affected in the original and the problem is not only in memory (RAM and SRAM) or DMA, but also in AICA channels too, the games uses all channels in a loop, such is the driver in SDK's...

Partially the problem can fix if we split channels on PC and make reading data from drive directly to sound memory. As I known GD DMA can transfer data to AICA memory from drive directly (by docs, not test it). But sound memory still will be used and AICA channels too...