its 16 channel wavetable/PCM chip, with (optional) stereo support.
Its also has envelope, this feature has similar as AY PSG's one but its shape is also stored at RAM, and each nibble in envelope data is for each output: so i decided to added some feature for more stereo-ish envelope.
Split: Envelope shape will be splitted to Left and Right half for each output.
HInv, Vinv: Envelope shape will be Horizontally/Vertically mirrored the left one.
Max sample length is sample bank size of Seta 2 arcade hardware (currently not emulated yet, nor it doesn't support on VGM).
Chip id is temporary, it can be changed with to suggestions.
OPM FM sound expansion by Yamaha, for their CX series MSX computers: It's needs converter when connect it to standard MSX cartridge slot.
Successor is SFG-05, It has YM2164 OPP instead YM2151 OPM.
YM2413 (drums mode)
Standalone YM2413 with allows drum channel.
Sound Expander for Commodore 64
OPL FM Sound expander cartridge for Commodore 64, it's placeholder until OPL is implemented.
MSX-MUSIC:
MSX's sound standard, appeared after MSX-AUDIO. it's basically OPLL FM sound expansion for MSX.
SSI 2001:
ISA Sound card with SID 6581. SID input clock is driven from ISA clock, so I modified flags value check routine.
Sound Blaster w/Game Blaster Compatible
Earliest Sound Blaster models has featured with Game Blaster compatiblity, It's has 2 SAA1099s like CMS/Game Blaster. It's removed at later models, but some hardware has just empty socket; you can restore this feature when you mount SAA1099 at empty socket.
Sharp X1:
Predecessor of X68000. it has built in AY PSG like competitors of the same period, but it has YM2151 FM sound addon in later models. FM sound is embedded in turbo Z, and that is succeeded by X68000.
X68000 hasn't AY, instead OKI MSM6258.
YM2151 in OutRun Board and X Board is 4MHz
