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59 lines
No EOL
2.1 KiB
Markdown
59 lines
No EOL
2.1 KiB
Markdown
# Neo Geo/Yamaha YM2610
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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.
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its soundchip is a 3-in-1: FM, YM2149 (AY-3-8910 clone) and ADPCM in a single package!
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# effects
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- `10xy`: set LFO parameters.
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- `x` toggles the LFO.
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- `y` sets its speed.
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- `11xx`: set feedback of channel.
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- `12xx`: set operator 1 level.
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- `13xx`: set operator 2 level.
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- `14xx`: set operator 3 level.
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- `15xx`: set operator 4 level.
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- `16xy`: set multiplier of operator.
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- `x` is the operator (1-4).
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- `y` is the mutliplier.
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- `18xx`: toggle extended channel 2 mode.
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- 0 disables it and 1 enables it.
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- only in extended channel 2 system.
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- `19xx`: set attack of all operators.
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- `1Axx`: set attack of operator 1.
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- `1Bxx`: set attack of operator 2.
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- `1Cxx`: set attack of operator 3.
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- `1Dxx`: set attack of operator 4.
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- `20xx`: set SSG channel mode. `xx` may be one of the following:
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- `00`: square
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- `01`: noise
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- `02`: square and noise
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- `03`: nothing (apparently)
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- `04`: envelope and square
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- `05`: envelope and noise
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- `06`: envelope and square and noise
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- `07`: nothing
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- `21xx`: set noise frequency. `xx` is a value between 00 and 1F.
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- `22xy`: set envelope mode.
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- `x` sets the envelope shape, which may be one of the following:
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- `0: \___` decay
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- `4: /___` attack once
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- `8: \\\\` saw
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- `9: \___` decay
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- `A: \/\/` inverse obelisco
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- `B: \¯¯¯` decay once
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- `C: ////` inverse saw
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- `D: /¯¯¯` attack
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- `E: /\/\` obelisco
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- `F: /___` attack once
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- if `y` is 1 then the envelope will affect this channel.
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- `23xx`: set envelope period low byte.
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- `24xx`: set envelope period high byte.
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- `25xx`: slide envelope period up.
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- `26xx`: slide envelope period down.
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- `29xy`: enable SSG auto-envelope mode.
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- in this mode the envelope period is set to the channel's notes, multiplied by a fraction.
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- `x` is the numerator.
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- `y` is the denominator.
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- if `x` or `y` are 0 this will disable auto-envelope mode. |