66 lines
2.3 KiB
Markdown
66 lines
2.3 KiB
Markdown
# Yamaha YM2151
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the sound chip powering several arcade boards and the Sharp X1/X68000. Eight 4-op FM channels, with overpowered LFO and almost unused noise generator.
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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.
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# effects
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- `10xx`: set noise frequency of channel 8 operator 4. 00 disables noise while 01 to 20 enables it.
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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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- `17xx`: set LFO speed.
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- `18xx`: set LFO waveform. `xx` may be one of the following:
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- `00`: saw
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- `01`: square
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- `02`: triangle
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- `03`: noise
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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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- `30xx`: enable envelope hard reset.
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- this works by inserting a quick release and tiny delay before a new note.
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- `50xy`: set AM of operator.
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- `x` is the operator (1-4). a value of 0 means "all operators".
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- `y` determines whether AM is on.
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- `51xy` set SL of operator.
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- `x` is the operator (1-4). a value of 0 means "all operators".
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- `y` is the value.
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- `52xy` set RR of operator.
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- `x` is the operator (1-4). a value of 0 means "all operators".
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- `y` is the value.
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- `53xy` set DT of operator.
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- `x` is the operator (1-4). a value of 0 means "all operators".
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- `y` is the value:
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- 0: +0
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- 1: +1
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- 2: +2
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- 3: +3
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- 4: -0
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- 5: -3
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- 6: -2
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- 7: -1
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- `54xy` set RS of operator.
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- `x` is the operator (1-4). a value of 0 means "all operators".
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- `y` is the value.
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- `55xy` set DT2 of operator.
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- `x` is the operator (1-4). a value of 0 means "all operators".
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- `y` is the value.
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- `56xx`: set DR of all operators.
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- `57xx`: set DR of operator 1.
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- `58xx`: set DR of operator 2.
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- `59xx`: set DR of operator 3.
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- `5Axx`: set DR of operator 4.
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- `5Bxx`: set D2R/SR of all operators.
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- `5Cxx`: set D2R/SR of operator 1.
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- `5Dxx`: set D2R/SR of operator 2.
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- `5Exx`: set D2R/SR of operator 3.
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- `5Fxx`: set D2R/SR of operator 4. |