Parameter Table - Roland GR-77B Owner's Manual

c. PARAMETER TABLE
DCO (Digitally Controlled Oscillator)
DCO is the Digitally Controlled Oscillator that controls
the pitch and generates the waveforms that are the
sound source of the synthesizers. Owing to its digitally
control system, this offers superior pitch stability com-
pared to the VCO (Voltage Controlled Oscillator). The
GR-778 has 2 DCO's.