The VL-1 was the first instrument of Casio's VL-Tone product line, and is sometimes referred to as the VL-Tone. It combined a calculator, synthesizer, and sequencer. Released in 1980 and selling for around £39.95 ($69.95 in the USA), the VL-1 is notable for its kitsch value among electronic musicians due to its cheap construction and its unrealistic, uniquely low-fidelity sounds. In particular its unique rhythm sounds are featured in tracks by several popular artists, including Trio's 1982 hit single 'Da Da Da'.

The 27-key keyboard had a range of two and a half octaves. Its sounds were mostly composed of filtered squarewaves with varied pulse-widths. It featured six voices; piano, fantasy, violin, flute, guitar, and ADSR. The ADSR function allowed you to create your own original sounds. The synthesizer was programmed by entering a number into the calculator section's memory, then switching back to keyboard mode. As well as this, the VL-1 also had changeable tone and balance, basic tempo settings and a real-time monophonic music sequencer, which could play back up to 99 notes. There were also 10 pre-loaded rhythms which utilized just three basic drum sounds.

The VL-1 featured a small LCD display capable of displaying 8 characters. This was primarily used for the calculator function, but also displayed notes played.