2022-01-16 06:10:43 +00:00
# Yamaha YM2151
2022-03-26 18:55:20 +00:00
the sound chip powering several arcade boards and the Sharp X1/X68000. Eight 4-op FM channels, with overpowered LFO and almost unused noise generator.
2022-03-22 05:58:07 +00:00
it also was present on several pinball machines and synthesizers of the era, and later surpassed by the YM2414 (OPZ) present in the world-famous TX81Z.
2022-01-16 06:10:43 +00:00
# effects
- `10xx` : set noise frequency of channel 8 operator 4. 00 disables noise while 01 to 20 enables it.
- `11xx` : set feedback of channel.
- `12xx` : set operator 1 level.
- `13xx` : set operator 2 level.
- `14xx` : set operator 3 level.
- `15xx` : set operator 4 level.
- `16xy` : set multiplier of operator.
- `x` is the operator (1-4).
- `y` is the mutliplier.
- `17xx` : set LFO speed.
- `18xx` : set LFO waveform. `xx` may be one of the following:
- `00` : saw
- `01` : square
- `02` : triangle
- `03` : noise
- `19xx` : set attack of all operators.
- `1Axx` : set attack of operator 1.
- `1Bxx` : set attack of operator 2.
- `1Cxx` : set attack of operator 3.
- `1Dxx` : set attack of operator 4.
