Structure
The technology used for a computer changed dramatically since the first practical use digital computer appeared in 1940's, but all computers work on Turing machine and an equivalent principle. Turing machine is the simplest programming machine which can calculate the number that is every computability. I decide whether I record a value in tape memory and carry out whether I move only one position of the head whether I compare the value of the sign that I took out with inside state when I take out an order and an input symbol line including data from the tape without the address-shaped working space, and the Turing machine wants to do it to a state change list and changes inside state and take out the next order. I repeat this procedure till I meet with the order of "the stop". As for the real computer, an order line and data becoming the program among the input symbol lines of the Turing machine and the renewal that it is it distinguish possible input and output line. In addition, input/output mechanism is added to use a calculation result. The input/output mechanism is used for replacing it of programing it. Because random access does memory with an address, the real computer improves by practice efficiency unlike Turing machine. However, the ultimate computing power (I can calculate the number that is every computability) does not change.