- The Abacus is thought to be the first computer, used long before the term was coined as this was in 500BC. It was developed by the Babylonians to aid simple arithmetic. It was not until 1623 that Wilhelm Schickard made a 'Calculating Clock' which could carry out simple arithmetic by adding and subtracting up to six digit numbers.
- In 1625 William Oughtred invented the slide rule.
- In 1642 the 'Pascaline' was invented by French mathematician, Blaise Pascal, and became fairly popular despite its simplicity.
- In 1668 Sir Samuel Morland invented an adding machine which was suitable for use with English money only.
- Many more simple adding machines were invented for the next 200 years but it was not until 1822 that the first mechanical computer was invented. Charles Babbage invented two machines, the Analytical Engine and the Difference Engine. The machines both worked in theory but at the time they were too complex to be successfully built. The machines used punched cards for input which were extremely early versions of the keyboards we use today.
- In 1853, father and son duo, the Scheutzes, completed the first Tabulating Machine. With 15 digit numbers and a printing output system, this was a huge development and was later built by a London firm, Brian Donkin. The first machine was bought by the Dudley Observatory in Albany, New York to produce astronomical tables. The director was later sacked for such an extravagant purchase. The Tabulating Machine Company later became IMB.
- A multitude of computers were invented and in 1941, the Z3 is thought to have been the world's first operational computer which was invented by Konrad Zuse.
- Colossus Computers were secretly devised by the British during the Second World War to break German codes. -
