Turing machine
A Turing machine is a hypothetical device that manipulates symbols on a strip of tape according to a table of rules.
Description
Despite its simplicity, a Turing machine can be adapted to simulate the logic of any computer algorithm.
At a very high level, the machine consists of a memory tape divided into cells.
A "head" (e.g. a pencil/eraser) traverses the memory one cell at a time, writing or erasing data (e.g. numerical digits) based on user-specified rules.
The "machine" was invented in 1936 by Alan Turing who called it an "a-machine" (automatic machine).
The Turing machine is not intended as practical computing technology, but rather as a hypothetical device representing a computing machine.
Turing machines help computer scientists understand the limits of mechanical computation.
Turing completeness is the ability for a system of instructions to simulate a Turing machine.
Programming languages
A programming language that is Turing complete is theoretically capable of expressing all tasks accomplishable by computers.
Nearly all non-markup programming languages are Turing complete.
See also
- Abstract machine
- Church, Alonzo
- Computer science
- Entscheidungsproblem
- Finite-state machine
- Lambda calculus
- Non-deterministic Turing machine
- Programming language
- Theoretical computer science
- Turing, Alan
- Turing completeness
- Universal Turing machine
External links
- Turing machine @ Wikipedia
- Web Turing machine @ appspot.com
