Turing Tumble

 This device was made by Alan Turing.It's a game that  demonstrates logic gates via mechanical computer. It's a teaching device primarily used for teaching on logical concept of computer programming.

It contains following major parts.

• Ball drops. The standard version uses two ramps which store a given number of balls. A switch at the bottom of the board triggers the release of the initial ball (typically blue), from the top left of the panel. The second ramp, on the right, contains red balls.
• Ramps and crossovers. The green ramp allows the balls to run down it one way and release it in only that direction, whereas the orange crossover lets balls traverse it to either side both ways, i.e. from right to left and vice versa.
• Interceptors. This black piece stops a ball.
• Bits. This is a one-bit storage: it changes direction when a ball rolls through, such that the next ball goes to the other side.
• Gear and gear bits. Gear bits are exactly like regular bits, but they can be connected to gears. The gears allow for linking state changes, thus integrally adding extra (abstract) power.