The Yamaha DX7 synthesizer’s clever exponential circuit, reverse-engineered #MusicMonday #ReverseEngineering @kenshirriff

Ken Shirriff continues reverse engineering the Yamaha DX7 digital synthesizer OPS “operator” chip that generated the sound waveforms. A key part of the OPS chip is an exponential circuit, which is used for frequency calculation and envelope application. Ken examines this circuit—implemented by a ROM, shifter, and other circuitry—in detail...