mirror of
https://github.com/tildearrow/furnace.git
synced 2024-11-18 02:25:11 +00:00
101 lines
3.6 KiB
Markdown
101 lines
3.6 KiB
Markdown
# Yamaha YM2608 (OPNA)
|
|
|
|
like YM2203, but with twice the FM channels, stereo, an ADPCM channel and built-in drums ("rhythm")!
|
|
|
|
it was one of the available sound chips for the NEC PC-88VA and PC-98 series of computers.
|
|
|
|
the YM2610 (OPNB) and YM2610B chips are very similar to this one, but the built-in drums have been replaced with 6 sample channels.
|
|
|
|
# effects
|
|
|
|
- `10xy`: **set LFO parameters.**
|
|
- `x` toggles the LFO.
|
|
- `y` sets its speed.
|
|
- `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.
|
|
- `18xx`: **toggle extended channel 3 mode.**
|
|
- `0` disables it and `1` enables it.
|
|
- only in extended channel 3 chip.
|
|
- `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.**
|
|
- `20xx`: **set SSG channel mode.**
|
|
- `00`: square
|
|
- `01`: noise
|
|
- `02`: square and noise
|
|
- `03`: nothing (apparently)
|
|
- `04`: envelope and square
|
|
- `05`: envelope and noise
|
|
- `06`: envelope and square and noise
|
|
- `07`: nothing
|
|
- `21xx`: **set noise frequency.** range is `0` to `1F`.
|
|
- `22xy`: **set envelope mode.**
|
|
- `x` sets the envelope shape, which may be one of the following:
|
|
- `0`: `\___` decay
|
|
- `4`: `/___` attack once
|
|
- `8`: `\\\\` saw
|
|
- `9`: `\___` decay
|
|
- `A`: `\/\/` inverse obelisco
|
|
- `B`: `\¯¯¯` decay once
|
|
- `C`: `////` inverse saw
|
|
- `D`: `/¯¯¯` attack
|
|
- `E`: `/\/\` obelisco
|
|
- `F`: `/___` attack once
|
|
- if `y` is 1 then the envelope will affect this channel.
|
|
- `23xx`: **set envelope period low byte.**
|
|
- `24xx`: **set envelope period high byte.**
|
|
- `25xx`: **slide envelope period up.**
|
|
- `26xx`: **slide envelope period down.**
|
|
- `29xy`: **enable SSG auto-envelope mode.**
|
|
- in this mode the envelope period is set to the channel's notes, multiplied by a fraction.
|
|
- `x` is the numerator.
|
|
- `y` is the denominator.
|
|
- if `x` or `y` are 0 this will disable auto-envelope mode.
|
|
- `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 SSG-EG of operator.**
|
|
- `x` is the operator (1-4). a value of 0 means "all operators".
|
|
- `y` is the value (0-8).
|
|
- values between 0 and 7 set SSG-EG.
|
|
- value 8 disables it.
|
|
- `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.**
|