71 lines
2.6 KiB
Markdown
71 lines
2.6 KiB
Markdown
# Yamaha YM2151
|
|
|
|
the sound chip powering several arcade boards, the Sharp X1/X68000 and the Commander X16. Eight 4-op FM channels, with overpowered LFO and almost unused noise generator.
|
|
|
|
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.
|
|
|
|
in most arcade boards the chip was used in combination with a PCM chip, like [SegaPCM](segapcm.md) or [OKI's line of ADPCM chips](oki.md).
|
|
|
|
# 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 multiplier.
|
|
- **`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.
|
|
- **`1Exx`**: set LFO AM depth.
|
|
- **`1Fxx`**: set LFO PM depth.
|
|
- **`30xx`**: enable envelope hard reset.
|
|
- this works by inserting a quick release and tiny delay before a new note.
|
|
- **`50xy`**: set AM of operator.
|
|
- `x` is the operator (1-4). a value of 0 means "all operators".
|
|
- `y` determines whether AM is on.
|
|
- **`51xy`**: set SL of operator.
|
|
- `x` is the operator (1-4). a value of 0 means "all operators".
|
|
- `y` is the value.
|
|
- **`52xy`**: set RR of operator.
|
|
- `x` is the operator (1-4). a value of 0 means "all operators".
|
|
- `y` is the value.
|
|
- **`53xy`**: set DT of operator.
|
|
- `x` is the operator (1-4). a value of 0 means "all operators".
|
|
- `y` is the value:
|
|
- 0: +0
|
|
- 1: +1
|
|
- 2: +2
|
|
- 3: +3
|
|
- 4: -0
|
|
- 5: -3
|
|
- 6: -2
|
|
- 7: -1
|
|
- **`54xy`**: set RS of operator.
|
|
- `x` is the operator (1-4). a value of 0 means "all operators".
|
|
- `y` is the value.
|
|
- **`55xy`**: set DT2 of operator.
|
|
- `x` is the operator (1-4). a value of 0 means "all operators".
|
|
- `y` is the value.
|
|
- **`56xx`**: set DR of all operators.
|
|
- **`57xx`**: set DR of operator 1.
|
|
- **`58xx`**: set DR of operator 2.
|
|
- **`59xx`**: set DR of operator 3.
|
|
- **`5Axx`**: set DR of operator 4.
|
|
- **`5Bxx`**: set D2R/SR of all operators.
|
|
- **`5Cxx`**: set D2R/SR of operator 1.
|
|
- **`5Dxx`**: set D2R/SR of operator 2.
|
|
- **`5Exx`**: set D2R/SR of operator 3.
|
|
- **`5Fxx`**: set D2R/SR of operator 4.
|