Squarewave, circuit-bent - Medeli MC-3

"This very common instrument is likely one of the last non- toy squarewave keyboards; it was regularly sold at least until 1995, and it is a "must to have" for every real squarewave lover because it is not rare and thus easy to find, has a relatively large keyboard, 4 note polyphony and accompaniment in the unique combination with the famous sounds of a Commodore C64 home computer or classic Gameboy. (Unfortunately none of the really freaky or more advanced C64/ SID sounds are built-in.). It has even a programmable(!) simple drum computer ("custom drummer", only 1 pattern) with 5 drumpad buttons and very electronic sounding special blip percussion. The accompaniment can play nicely disharmonic because it accepts any note combinations and not only those few those establishment defined to be "chords"....(from WarrantyVoid )"

5 switches were installed on this synth to control digital data flow from FM chip to CPU. By turning off one or more of this switches you get interesting new sounds/noises.