33 lines
1.1 KiB
Markdown
33 lines
1.1 KiB
Markdown
# Arcade (Yamaha YM2151/PCM)
|
|
|
|
this chip combination was used in the Sega OutRun, X and Y arcade boards, and perhaps a few others.
|
|
the actual PCM chip had 16 channels, but the number has been cut to 5 in DefleMask for seemingly arbitrary reasons.
|
|
|
|
# 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.
|
|
- `1Exx`: set AM depth.
|
|
- `1Fxx`: set PM depth.
|
|
- `20xx`: set PCM frequency.
|
|
- only works on the PCM channels.
|
|
- `xx` is a 256th fraction of 31250Hz.
|