Casiotone

Casiotone refers to a series of home electronic keyboards released by Casio Computer Co. in the early 1980s.

These first keyboards used a sound synthesis technique known as Vowel-Consonant synthesis to approximate the sounds of other instruments (albeit not very accurately). Most Casiotone keyboards were small, with miniature keys designed for children's fingers, and were not intended for use by professional musicians; they usually contained a rhythm generator, with several user-selectable rhythm patterns, and often the means to automatically play accompaniments. While the name "Casiotone" disappeared from Casio's new keyboard catalog when more accurate synthesis technologies became prevalent, their low cost and abundance made them fairly common fixtures in garage rock bands. Musicians and bands known to use Casiotone keyboards include: Alexis Taylor of Hot Chip, Dan Deacon, Lettie, Maurizio Arcieri of Krisma, Kevin Parker of Tame Impala, Turnstyle, Trio, Cobol Pongide and Hedluv, Chiara Lee of .

Old Casiotone keyboards came in three distinct families, separated by the method of synthesis.

The later, more professional range of keyboards, the CZ series, used phase distortion synthesis, which is mathematically almost identical to Yamaha's frequency modulation synthesis, although implemented slightly differently in order to avoid patent infringement.

After the release of famous Casio SK-1 in 1985, gradually PCM sample based tone generator became dominant in Casio keyboards line. After the 1990s, most Casio keyboards utilize PCM tone generator or its variants.

...
Wikipedia