First in what would become a long line of cheap keyboard instruments, Casio's VL-Tone boasts four instrument presets, white-noise beats, a 100 step sequencer - and here's where the "convergence" part comes in - a calculator!

The VL-Tone had some famous users like Devo and Human League, but most recently you may remember a car ad featuring the band Trio's song "DaDaDa" which uses a VL-tone beat throughout. Besides its novelty and historic value, there's little that makes the VL-tone an interesting "keyboard" today, though you have to admire Casio including some limited sound creation capabilites.

After mention of the VL-tone, people always bring up the Kraftwerk song "Pocket Calculator" - specifically the line "it plays a little melody". Folks often think that this song uses the VL-tone, but it doesn't. "Pocket Calculator" is more a tribute to the VL-tone - and why not? Combining a little synth and a calculator is a great idea. As cool and flexible as modern synthesizers are today, you still can't use one to figure out how much to tip on a lunch split three ways.