Computers have evolved through different stages before reaching their present state of development. The history of the computer dates back to 3000 BC. Different stages of its development are as follows:
3000 BC - Invention of the Abacus
AD 1500 - Mechanical calculator invented by Leonardo da Vinci
AD 1621 - Slide rule invented.
AD 1640 - Blaise Pascal invents the Arithmetic Machine
AD 1800 - Jacquard invents the first punch cards for storing data
AD 1822 - Charles Babbage invents the Difference Engine
AD 1830 - Charles Babbage invents the analytical Engine
AD 1857 - Sir Charles Wheatstone uses paper tape to store data
AD 1926 - The first patent for semiconductor transistor was filed.
AD 1936 - Dvorak keyboard created.
AD 1937 - Alan Turing defines the Turing Test.
AD 1940 - Konrad Zuse completes the first fully-functioning electro-mechanical computer of the world.
AD 1943 - The first electronic general-purpose computer, ENIAC, produced.