Yamaha YM2203

It was the progenitor of Yamaha's OPN family of FM synthesis chips used in many video game and computer systems throughout the 1980s and early 1990s.

It was used in a variety of NEC computers, along with various arcade game machines.

The YM2203 has the following features: The YM2203 and the rest of the OPN synthesizer family generate sound via frequency-modulated digital sine waves.

It included 12 operator "cells", each generating a 13-bit sine wave at a programmable frequency, the volume of which is controlled by a programmable ADSR envelope generator.

The ADSR parameters, multiplier and detune settings for each operator, combined with the algorithm, make up what are known as instrument patches.