Tone signal generator for producing multioperator tone signals using an operator circuit including a waveform generator, a selector and an enveloper

A system for generating a frequency modulation (FM) multioperator tone comprising:

• an operator circuit, the operator circuit generating a plurality of virtual operator outputs, each virtual operator output being generated during a respective time slot, the operator circuit including a storage location, the storage location holding the virtual operator output of one of the plurality of virtual operator outputs, the operator circuit using the operator output of the one of the plurality of virtual operator outputs as a modulation input for a next sequential virtual operator of the plurality of virtual operator outputs, the operator circuit including
• a waveform generator that furnishes a waveform signal in response to a phase angle address signal, the waveform generator comprising a plurality of wave tables, each storing a different waveform,
• a selector that selects one of the wave tables in response to a plurality of selection signals such that the selected wave table provides the waveform signal upon being addressed by the phase angle address signal, whereby selection of the selected wave table varies with each selection signal, and
• an enveloper that impresses an envelope signal on the waveform signal to produce an enveloped signal, the enveloped signal being used as a carrier or modulator for generating the FM multioperator tone, and
• an output accumulator, the output accumulator selectively receiving each of the plurality of virtual operator outputs, the output accumulator selectively accumulating some of the plurality of virtual operator outputs to provide the multioperator tone.