Turing Tumble

Turing Tumble is a mechanical computer created by Paul Boswell in 2017, operated by marbles. It is targeted for education, but with a big enough board could allow to build any contraption and is Turing Complete.

Marbles move down the board by gravity, controlled by 6 types of parts you can add to the board. When a marble hits the bottom, a new marble from the top is released. Two types of marbles can be released, blue or red.

External resources

 * Turing Tumble kickstarter page with video explanation
 * Emulator in JavaScript