Turing machine

abstract computation model; mathematical model of computation that defines an abstract machine which manipulates symbols on a strip of tape according to a table of rules

ability of a computing system to simulate Turing machines

may have a set of rules that prescribes more than one action for a given situation; state and tape symbol no longer uniquely specify things; rather, many different actions may apply for the same combination of state and symbol

two-dimensional Turing machine with emergent behavior

turing machine that can simulate an arbitrary Turing machine on arbitrary input by reading both the description of the machine to be simulated as well as the input thereof from its own tape

non-deterministic Turing machine which chooses between the available transitions at each point according to some probability distribution

abstract machine used to study decision problems

model of quantum computation

hypothetical computational model

A 2-state 2-color turmite on a square grid. Starting from an empty grid, after 8342 steps the turmite (a red pixel) has exhibited both chaotic and regular movement phases.|thumb|250x250px

Turing machine that always halts for any input

essay by Roger Penrose

hypothetical computing device

essay by Roger Penrose

abstract calculator

graph Machine

hypothetical computing devices