GS1

Since licensing the FM tone generator developed by Stanford University in 1973, Yamaha focused on creating a digital tone generator for the Electone.
One month after the debut of the F-70, Yamaha released the GS1, which featured the FM tone generator as well as a two types of touch control function, which changes the tone depending on how hard the keys are played.
Chick Corea headlined the Japanese catalog for the GS1.