mirror of
https://github.com/tildearrow/furnace.git
synced 2024-11-06 21:05:04 +00:00
99 lines
3.6 KiB
Markdown
99 lines
3.6 KiB
Markdown
# Neo Geo/Yamaha YM2610
|
|
|
|
originally an arcade board, but SNK shortly adapted it to a rather expensive video game console with the world's biggest cartridges because some people liked the system so much they wanted a home version of it.
|
|
|
|
its soundchip is a 4-in-1: 4ch 4-op FM, YM2149 (AY-3-8910 clone) and 2 different format ADPCM in a single package!
|
|
|
|
# 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 2 mode.
|
|
- 0 disables it and 1 enables it.
|
|
- only in extended channel 2 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. `xx` may be one of the following:
|
|
- `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. `xx` is a value between 00 and 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.
|