What is MSX-Music?
(thanks to FRS) MSX-Music is a standard for FM-based sound-generation on MSX. It came later (1987) than the MSX-Audio standard (1985), as a Panasonic proprietary extension, the FM-PAC. It is using a more limited version of the MSX-Audio BIOS, patched to use the much cheaper and incompatible Yamaha YM2413. This means it blocks ADPCM commands explicitly and that only 1 user-instrument can be used at a time. The size is also smaller: only 16kB. It’s obscure why Panasonic did choose the YM2413 to build an incompatible cheaper sound cartridge for the MSX when they could have chosen the YM3526, which was 100% FM compatible with the Y8950 (MSX-Audio), lacking only the ADPCM registers. The ADPCM commands could then just be blocked, as they did on the MSX-Music BIOS. Being incompatible with the MSX-Audio, the MSX-Music was not designed to be used for direct OPLL access, but many games did it. ASCII got even further on weakening the standard when made the terrible mistake of choosing the MSX-Mus
