Turing Tumble
Videos
Turing Tumble is a game and demonstration of logic gates via mechanical computing.
A beginner's Turing Tumble layout
Digi-Comp II
Videos
The Digi-Comp II was a toy computer invented by John "Jack" Thomas Godfrey (1924–2009) in 1965 and manufactured by E.S.R., Inc. in the late 1960s, that used 1⁄2 inch (12.5 mm) marbles rolling down a ramp to perform basic calculations.
Huge wooden replica of Digi-Comp II by Evil Mad Scientist. The original is a much smaller toy made of wood and plastic.