40 lines
1.5 KiB
Markdown
40 lines
1.5 KiB
Markdown
# Yamaha YM2413/OPLL
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the YM2413, otherwise known as OPLL, is a cost-reduced FM synthesis sound chip, based on the Yamaha YM3812 (OPL2). thought OPL was downgraded enough? :p
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OPLL spawned also a few derivative chips, the best known of these is:
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- the myth. the legend. THE VRC7. 6 channels, *rather interesting* instruments sound bank, no drums mode
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- Yamaha YM2423, same chip as YM2413, just a different patch set
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- Yamaha YMF281, ditto
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# technical specifications
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the YM2413 is equipped with the following features:
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- 9 channels of 2 operator FM synthesis
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- A drum/percussion mode, replacing the last 3 voices with 3 rhythm channels
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- 1 user-definable patch (this patch can be changed throughout the course of the song)
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- 15 pre-defined patches which can all be used at the same time
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- Support for ADSR on both the modulator and the carrier
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- Sine and half-sine based FM synthesis
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- 9 octave note control
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- 4096 different frequencies for channels
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- 16 unique volume levels (NOTE: Volume 0 is NOT silent.)
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- Modulator and carrier key scaling
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- Built-in hardware vibrato support
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# effects
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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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- `16xy`: set multiplier of operator.
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- `x` is the operator (1 or 2).
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- `y` is the mutliplier.
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- `18xx`: toggle drums mode.
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- 0 disables it and 1 enables it.
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- only in drums 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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