Casio VL-Tone, keyboard
The Casio VL1 (or VL-Tone) was one of those truly bizarre products in musical history.
Half calculator, half 'synthesiser'... it had almost nothing to redeem itself other than its low cost - you certainly didn't buy one for its sounds which, as you might imagine, were cheap and cheezy. Apparently, the thing was originally designed to be produced solely as a 'musical instrument' (I use the term loosely!). One of the four Kashio brothers who founded the company was a would-be musician as well as an electronics engineer and he had designed a simple and inexpensive LSI (Large Scale Integration) chip that could be used for musical purposes but executives at the company weren't confident that it had enough features to sell in its own right so some bright spark at Casio had the idea to add (no pun intended!) a calculator! Obvious really! What else would you add to a small, portable musical instrument?! I guess that as one of the world's leaders in calculator manufacture, they had the technology for free.