Domino computer

Some constructs are reminiscent of digital circuits, suggesting that not only telegraph-like tools can be shown, but also simple information processing modules.

At the Manchester Science Festival in 2012, mathematician Matt Parker and a team of volunteers worked together to build a domino binary adder which could add two three-bit inputs and produce a 3-bit output, which ran successfully.

The following day, they attempted to build a 4-bit adder, which they completed, but the final test run had some errors (one due to signal bleed between chains of dominoes, and one timing issue).

[7] In 2018, at Bank Muscat headquarters in Oman, a team of American British Academy (ABA) Grade 12 students led by Saatvik Suryajit Korisepati, assisted by Alex Freyer, Zoltan Sojitory, and other computer students, used 15,000 dominoes to build a 5-bit adder able to add any numbers up to the sum of 63.

[8] In January 2024, a team of Finnish high school students successfully built a 6-bit adder out of over 10,000 dominoes.

An OR gate built from dominoes, with the bottom left and bottom right dominoes as its inputs and the top domino as its output. If the bottom left or the bottom right domino is pushed (or if both are pushed), then the top domino will fall; if neither is pushed, it will not fall.
A NOT gate implemented in a domino computer; when A is knocked down, the path from PWR to NOT A is interrupted, so NOT A remains standing.
The two domino logic gates, from which, with the addition of NOT, all other gates can be built. The XOR gate is dependent on timing.