Bob Yannes

Robert "Bob" Yannes (born 1957) is an American electronic engineer who designed the SID audio generator chip for the Commodore 64 and co-founded digital synthesizer company Ensoniq. He designed the Ensoniq 5503 Digital Oscillator Chip (DOC) which was used in both commercial synthesizers and the Apple IIGS home computer.

Biography[edit]

Robert Yannes graduated from Villanova University in 1978. He started out as an electronic music hobbyist before being hired as a chip designer at MOS Technology which had become a part of Commodore. Al Charpentier recruited Yannes partly for his music synthesis knowledge.^[1] He has been infatuated by electronic music since the early 1970s. He claims the song Lucky Man by Emerson, Lake & Palmer influenced him more than any other single song, and also lists Kraftwerk and Mike Oldfield among his influences.^[2]

He designed the MicroPET with help from Al Charpentier which became an unintended prototype for the VIC-20 home computer.

He designed the single-chip sound synthesizer voice chip SID (6581) with enough resolution to produce high-quality music. However, he was unable to refine the signal-to-noise ratio which he desired. He hoped the chip would find its way into polyphonic/polytimbral synthesizers. The SID chip was his first attempt at a phase-accumulating oscillator, the heart of all Wavetable-lookup synthesis.

After he left MOS Technology he co-founded Ensoniq in 1982. The Ensoniq sound chips had multiplexed oscillators designed in such a way that it was possible to produce more voices per chip, typically 32 for Ensoniq's DOC, OTIS, and OTTO sound chips (48 for the final OTTO-48). Given less time constraints than for the SID chip design, a proper MOS op-amp could be implemented to eliminate signal leakage and an improved filter to achieve high resonance. Current^[when?] designs include waveform interpolation, digital filters, and digital effects.^[1]

References[edit]

^ ^a ^b stud1.tuwien.ac.at - Interview with Bob Yannes, 1996-08-30
^ Bagnall, Brian (2005). "The Secret Project 1981". On the Edge - The Spectacular Rise and Fall of Commodore (1 ed.). Winnipeg, Manitoba: Variant Press. pp. 231–237. ISBN 0-9738649-0-7.

[iwya-1] stud1.tuwien.ac.at - Interview with Bob Yannes, 1996-08-30

[bagnall-2] Bagnall, Brian (2005). "The Secret Project 1981". On the Edge - The Spectacular Rise and Fall of Commodore (1 ed.). Winnipeg, Manitoba: Variant Press. pp. 231–237. ISBN 0-9738649-0-7.

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