In the context of the YM2413, an instruments.bin file is a binary container that stores the parameter data required to program the User Instrument slot (and sometimes overwrite the hardcoded presets in software emulation).

: It was also used in some home computers of the era, providing a richer audio experience.

The famous is a small binary file (often 48 bytes) that writes custom FM parameters into the user instrument slot (channel 8 or channel 0 depending on implementation).

The YM2413, also known as , contains a built-in internal ROM with 15 hard-coded instrument presets (like piano, violin, and flute) and one user-definable slot.