75 lines
2.7 KiB
Markdown
75 lines
2.7 KiB
Markdown
# Yamaha YM2151
|
|
|
|
the sound chip powering several arcade boards, synthesizers and the Sharp X1/X68000. 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](msm6295.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 new MULT value..
|
|
- `17xx`: **set LFO speed.**
|
|
- `18xx`: **set LFO waveform.**
|
|
- `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.**
|
|
|
|
## info
|
|
|
|
this chip uses the [FM (OPM)](../4-instrument/fm-opm.md) instrument editor.
|