The Casio SK-1 is a small sampling keyboard made by Casio in 1985. It has 32 small sized piano keys, four-note polyphony, with a sampling bit depth of 8 bit PCM and a sample rate of 9.38 kHz for 1.4 seconds, a built-in microphone and line level and microphone inputs for sampling, and an internal speaker and line out. It also features a small number of four-note polyphonic preset analog and digital instrument voices, and a simple additive voice. The SK-1 includes one pre-arranged piece of music, the Toy Symphony, which is played when the "Demo" button is pressed.