The Korg DVP-1 Digital Voice processor was released in the early 1980's. It consisted of a Vocoder with its own internal waveforms, a five part Harmonizer, a Pitch-shifter and an Internal Synth. The Vocoder is very intelligible. While the Harmonizer does not sound super realistic, it has its own unique effect. It has five polyphonic voices, four with chorus on, unison mode and 64 memory patches to store your settings. It has been used by Vangelis, Matrix and GASR.