The most thorough reference I've found for the Game Boy SPU is unfortunately the Gambatte source code itself since it's a fairly accurate emulator and open sour

The most thorough reference I've found for the Game Boy SPU is unfortunately the Gambatte source code itself since it's a fairly accurate emulator and open source. Unfortunately it's also not the most human-readable code (due to micro-optimizations and lack of comments, plus it's C++ which is already a -10 handicap in readability). In the meantime you can try to dig around my code which is not nearly as accurate but (hopefully) should be easier to understand: https://github.com/simias/gaembuoy/blob/master/spu.c https://github.com/simias/gaembuoy/blob/master/spu.c It seems to work fine with all games I've tested, although of course that's only a tiny subset of the console's library...