While the chip provides 9 channels of FM synthesis or 6 FM channels plus 5 percussion instruments, its true power lies in its capability for . The data defining these sounds—patches, operator settings, and envelope behaviors—is often stored in a binary format known as instruments.bin .
But many tools expect (e.g., MSX PLAYER), so you can repeat or combine patches. ym2413+instrumentsbin
| Byte | Parameter | Description | |------|-------------------------|-------------| | 0 | Feedback / Algorithm | Bits 0-2 = algorithm (1 or 0), bits 3-5 = feedback | | 1 | Operator 1 (Carrier) | Multiplier, total level (MSB), KSR, etc. | | 2 | Operator 2 (Modulator) | Same as above | | 3 | Operator 3 (Carrier) | Same as above | | 4 | Operator 4 (Modulator) | Same as above | | 5 | Attack / Decay 1 | AR (4 bits) + DR (4 bits) for operator 1 | | 6 | Attack / Decay 2 | AR + DR for operator 2 | | 7 | Sustain / Release (all) | SR (4 bits) + RR (4 bits) for all operators | While the chip provides 9 channels of FM
Unlike most FM synthesis chips that require every instrument to be programmed from scratch, the YM2413 features a built-in Instruments ROM containing 15 hard-coded melody patches and 5 rhythm sounds. total level (MSB)