History of Computers - Turing Machine
The Turing machine is a theoretical concept for a computer conceived by Alan Turing in 1936.
Overview
A Turing machine consists of four parts: an infinitely long strip of tape divided into separate cells, each with a symbol on it, a "head" which reads the tape, a "state register" which stores the current state of the machine, and a table of instructions. The table has instructions that usually say "move to cell x" or "change the symbol on cell x and move to cell y", and correspond with the current cell the machine is reading.[1] It is not intended as a practical computer, but as a theoretical idea of a computer. It was introduced by Alan Turing in his 1936 paper "On Computable Numbers, with an Application to the Entscheidungsproblem."[2] The idea was further developed in his 1948 paper "Intelligent Machines."
Significance
The Turing machine is significant to the history of computing because it provides the basis and definition for all computer algorithms. The programming of the algorithm are represented by the table of instructions, and the input and output are represented by the tape. It is also significant today because it was the first concept of the computers we see and use in our lives. It is similar in most respects to the computers of today: it is programmable, has expandable storage space and rewriteable memory in the tape, and even has a form of ROM in the table of instructions.
References
- ↑ http://plato.stanford.edu/entries/turing-machine/
- ↑ http://www.cs.virginia.edu/~robins/Turing_Paper_1936.pdf
