The Donca-Matic or Disc Rotary Electric Auto Rhythm machine DA-20
was a japanese electro-mechanical drum machine designed as an
improvement on the Wurlitzer
Sideman rhythm machine. This instrument was the first product for what
was to become the
Korg Musical Intrument company. The DA-20 despite being a primitive machine was a major breakthrough
in its day, the DA-20 was soon replaced by an all electronic solid
state model in 1966 the Donca DE-20.