Add EPSM sound expansion

[ghost]

https://famistudio.org/

According to the FamiStudio, they modded the NES with EPSM sound expansion mod

[carmiker]

This is a fairly big ask. It's a rather complex Yamaha FM synthesizer with SSG support. I've emulated the SSG portion myself and ported the OPN portions Aaron Giles' amazing YMFM project to C, so I have some familiarity. However, the problem is integrating such code into Nestopia. The APU and more specifically the resampling methodology is extremely complex, and actually not even very high quality -- I am hoping to replace the internal resampler in order to pass APU tests that currently fail. When I do that I may look at the feasibility of adding yet another addon sound chip to Nestopia.

[MinecraftMario27]

Actually, it's YMF288. Mesen-X is only the NES Emulator that plays EPSM/YMF288. YMF288/EPSM is the sound chip that has 3 Square Channels SSG, 6 FM Channels, 6 Drums. FamiStudio, NES Music Maker has EPSM audio expansion and FamiStudio has ROM export (.nes .fds). Similar to FamiTracker