In 1982 Bob Yannes, who would later co-found Ensoniq, was given the task of developing a soundchip for the Commodore 64 in the shortest possible time. At that time, he worked at MOS Technology, one of Commodore's main suppliers. "MOS 6581 Sound Interface Device" - the SID-chip - was a very well-constructed sound-chip for its time. Sequential Circuits were also interested in buying it in large amounts. Because of its hectic phase of development, full documentation of the chip's possibilities was never finalized: the first one was written for the prototype and it changed so many times that, like Bob Yannes told in an interview with Andreas Varga, it didn't make sense at all anymore. Nonetheless, the SID's possibilities were soon recognised, mainly by the game-producers who assured the huge success of the Commodore 64. Until then there had not been a soundchip of that calibre in a home-computer. The SID remained one of the main chips in the field for a good few years. This chip was Bob Yannes first shot at developing a phase-accumulating oscillator, the fundament of all wavetable synthesis-based systems. At the beginning, he had planned to sell the SID mainly to the synthesizer industry, but the production capacity could hardly keep up with the growing demand for the C64. Once there were enough chips, Yannes wasn't working for Commodore anymore.