YM2413 , also known as OPLL (short for FM Operator Type-LL ), is an electronic component, a sound generator chip , developed by Yamaha in the mid-1980s. It is best known for using MSX-Music standard audio expansion devices for home computers using the MSX standard, and as an additional sound synthesizer in the Sega Mark III game console . It was also used in a number of arcade slot machines , from 1987 to 1998 .
A similar (but not identical) YM2413 FM synthesizer device was also used in the Lagrange Point game for the Famicom game console. This game used the Konami VRC7 extended memory management chip (mapper) developed by Konami , which also included the FM synthesizer.
Description
YM2413 is the most cheapened version of the YM3812 chip (OPL2). To reduce the price of the device and the capabilities of the chip have been greatly simplified. It allows you to use only one user-defined tool, and also has a set of 15 tools predefined in the manufacture, the parameters of which cannot be changed by the user. Also, the number of possible waveform options is reduced to two, and the number of control registers is markedly reduced. In addition, there is no signal addition circuit for mixing output signals from different channels. Instead, the time separation method is used. The 9-bit DAC of the microcircuit outputs the output values ββof all channels in turn, and its output usually passes through an external analog filter .
A set of 15 predefined tools includes the following tools (according to the documentation):
- 1 - violin
- 2 - acoustic guitar
- 3 - piano
- 4 - flute
- 5 - clarinet
- 6 - oboe
- 7 - pipe
- 8 - organ
- 9 - horn
- 10 - synthesizer
- 11 - harpsichord
- 12 - vibraphone
- 13 - synthesizer bass
- 14 - acoustic bass
- 15 - electric guitar
The names of the instrument sounds are conditional, reflecting their approximate similarity to real instruments. In fact, the quality of the synthesis of instruments is very low, which does not provide recognition of tones, and also contains a high level of noise.
Tool number 0 is user defined. Any of the tools, including the custom one, can be used simultaneously on several channels. Each channel can be assigned volume (16 levels) and pitch (range of 8 octaves) of sound.
Like other chips in the OPL series, the YM2413 has a 6-channel synthesizer mode with 5 predefined percussion instruments. For this chip, this mode is important, since one user instrument is not enough to implement drums in music. The height of the percussion instruments in the 6-channel synthesizer mode cannot be changed.
The drum kit contains the following sounds that mimic the drum kit :
- bass drum (barrel)
- snare drum
- Tom
- crash
- hi-hat
Specifications
- 9 channels of 2 operator synthesis
- A 6-channel synthesizer mode plus 5 percussion instruments is also available.
- Only one tool can be defined by the user.
- One available waveform of the generators (sinusoidal)
- Integrated DAC
- Two separate outputs for melodic and percussion instruments
Links
- YM2413 Application Manual - official documentation on the use of the chip, translated into html format.