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What is a computer?
A computer is an electronic machine that accepts information, stores it, processes it according to the instructions provided by a user and then returns the result. -
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Abacus
Was invented in 2600 BC by Chinese -
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Cogs
The machine had a series of interlocking cogs (gear wheels with teeth around their outer edges) that could add and subtract decimal numbers. -
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Calculators
It is a measure of the brilliance of the abacus, invented in the Middle East circa 500 BC, that it remained the fastest form of calculator until the middle of the 17th century. Then, in 1642, aged only 18, French scientist and philosopher Blaise Pascal (1623–1666) invented the first practical mechanical calculator, the Pascaline, to help his tax-collector father do his sums. -
Engines of Calculation
A computer, on the other hand, is a machine that can operate automatically, without any human help, by following a series of stored instructions called a program (a kind of mathematical recipe). Calculators evolved into computers when people devised ways of making entirely automatic, programmable calculators. The first person to attempt this was a rather obsessive, notoriously grumpy English mathematician named Charles Babbage . -
"Father of computers"
Many regard Babbage as the "father of the computer" because his machines had an input (a way of feeding in numbers), a memory (something to store these numbers while complex calculations were taking place), a processor (the number-cruncher that carried out the calculations), and an output (a printing mechanism)—the same basic components shared by all modern computers. During his lifetime, Babbage never completed a single one of the hugely ambitious machines that he tried to build. -
Charles Babbage
Almost all computers in use today follow this basic idea laid out by Babbage, which is why he is often referred to as 'the father of computers.' The analytical engine was so complex that Babbage was never able to build a working model of his design. It was finally built more than 100 years later by the London Science Museum. -
Turning-tested
One of the key figures in the history of 20th-century computing, Alan Turing (1912–1954) was a brilliant Cambridge mathematician whose major contributions were to the theory of how computers processed information. In 1936, at the age of just 23, Turing wrote a groundbreaking mathematical paper called "On computable numbers, with an application to the Entscheidungsproblem," in which he described a theoretical computer now known as a Turing machine -
Bush and the bomb
At the time when C-T-R was becoming IBM, the world's most powerful calculators were being developed by US government scientist Vannevar Bush (1890–1974). In 1925, Bush made the first of a series of unwieldy contraptions with equally cumbersome names: the New Recording Product Integraph Multiplier. Later, he built a machine called the Differential Analyzer, which used gears, belts, levers, and shafts to represent numbers and carry out calculations in a very physical way, like a gigantic mechanica -
First electronic computer
The very first electronic computers were developed by Konrad Zuse in Germany in the period 1935 to 1941. The Z3 was the first working, programmable and fully automatic digital computer. The original was destroyed in World War II, but a replica has been built by the Deutsches Museum in Munich. -
First modern computer
The World War II years were a crucial period in the history of computing, when powerful gargantuan computers began to appear. Just before the outbreak of the war, in 1938, German engineer Konrad Zuse (1910–1995) constructed his Z1, the world's first programmable binary computer, in his parents' living room. -
First modern computers
The following year, American physicist John Atanasoff (1903–1995) and his assistant, electrical engineer Clifford Berry (1918–1963), built a more elaborate binary machine that they named the Atanasoff Berry Computer (ABC). It was a great advance 1000 times more accurate than Bush's Differential Analyzer. These were the first machines that used electrical switches to store numbers: when a switch was "off", it stored the number zero; flipped over to its other, "on", position, it stored the number -
ENIAC
Around the same time, the British built the Colossus computer to break encrypted German codes for the war effort, and the Americans built the Electronic Numerical Integrator Analyzer and Computer, or ENIAC. Built between 1943 and 1945, ENIAC weighed 30 tons and was 100 feet long and eight feet high.
