Our LEGO Turing machine uses a tape based on a classic interpretation of computer memory: switches. Additionally, it uses a light sensor to determine the value of a switch: if the switch is on, the sensor will see the black colour of the switch’s surface. But if it is turned off, the sensor will see the white colour of the LEGO beam, making it possible to distinguish between the states. Finally, a rotating beam mounted above the tape can flip the switch in both directions.
The team used a software to execute programs in a basic Turing machine language that can be found on github.
Wikipedia defines a Turing machine is “a device that manipulates symbols on a strip of tape according to a table of rules. Despite its simplicity, a Turing machine can be adapted to simulate the logic of any computer algorithm, and is particularly useful in explaining the functions of a CPU inside a computer.” The creators point out that despite being called a ‘machine,’ a Turing machine is not a physical machine rather its a a theoretical model of a of a computer that can do anything the computers of today or tomorrow can do.
More on the LEGO Turing Machine here: legoturingmachine.org/
More info on the exposition here: cwi.nl/2012-alan-turing-year (in Dutch)
More info on the making of this video here: ecalpemos.nl/2012/06/18/lego-turing-machine-video/