Friday, October 26, 2007

A Brief History of Computers (1600 - 1940)

Computers are a significant part of today's society. Most of us have computers around us all the time. But computers have come a long way, further than most people realize.

The first automatic calculator was built in 1623 by Wilhelm Schikard. It was of course, completely mechanical, and not at all electrical or electronic. It could only add and subtract numbers up to six digits. Similar devices capable of adding numbers with more digits or in different bases were made soon after.

In 1671, Gottfried Liebniz made a machine that could multiply numbers. Liebniz also refined the binary system used in all modern computers. In 1774, Philipp Hahn built a calculator capable of all four primary functions.

In 1791, Charles Babbage was born. Although he never actually completely any calculating machines, his work was far ahead of his time and he was very influential. In 1822, he began designing his "difference engine" which would solve sixth-degree polynomials up to thirty digits.
Unfortunately, he lost support for the difference engine, so he began designing the "analytical engine", a general purpose computer, run off steam power, that could be programmed with punch cards and that would be capable of doing any computation modern computers can do. Had it been finished it would have been the first Turing machine, before Turing was even born.

In 1906 vacuum tubes were invented by Lee De Forest. In 1919 William Eccles and F. W. Jordan developed the first flip-flop circuit, a necessary component of electrical computers. In 1924, William Bothe built an AND logic gate, another necessary component of electrical computers. In 1930, Vannevar Bush built a partly electrical version of Babbage's difference engine, capable of solving differential equations.

In 1936, Alan Turing published a paper in which he introduced the concept of a Turing machine and showed that it is impossible to have a general solution to whether a program will continue infinitely or not. A Turing machine is a theoretical machine that read a tape and perform actions on the tape based off instructions on the tape.

Next time: A history of computers from 1940 to present.

No comments: