OPL1

OPL1, short for Operator Type-L, is the first member of Yamaha's OPL family of FM synthesis integrated circuits. It was designed as an affordable FM synthesis chip for consumer electronics and early personal computers. The design implements operator-based frequency modulation, allowing a small set of four-operator voice channels and configurable operators per voice, enabling a range of timbres from bell-like tones to metallic textures. It includes envelope generation and user-accessible registers to control operator levels, frequencies, and modulation.

Released in the 1980s, OPL1 laid the groundwork for Yamaha's subsequent OPL2 and OPL3 devices, which expanded the number of channels and operator configurations and became widely used in sound cards such as AdLib and Sound Blaster-compatible hardware. While OPL1 itself saw limited direct adoption in mainstream PC sound cards, its concept and architecture influenced later chips and FM synthesis on PC hardware.

Today, OPL1 is mainly of historical interest. It is studied by retro-computing enthusiasts and musicians as the progenitor of the FM-synthesis lineage that dominated 1980s and early 1990s computer sound.