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The 19th Century: First Programmable Computing Devices |
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Until the 19th century "early computers", probably better described as calculating machines, were basically mechanical devices and operated by hand. Early  calculators like the abacus worked with a system of sliding beads arranged on a rack and the centerpiece of Leibniz's multiplier was a stepped-drum gear design.
Therefore Charles Babbage's proposal of the Difference Engine (1822), which would have (it was never completed) a stored program and should perform calculations and print the results automatically, was a major breakthrough, as it for the first time suggested the automation of computers. The construction of the Difference Engine, which should perform differential equations, was inspired by Babbage's idea to apply the ability of machines to the needs of mathematics. Machines, he noted, were best at performing tasks repeatedly without mistakes, while mathematics often required the simple repetition of steps.
After working on the Difference Engine for ten years Babbage was inspired to build another machine, which he called Analytical Engine. Its invention was a major step towards the design of modern computers, as it was conceived the first general-purpose computer. Instrumental to the machine's design was his assistant, Augusta Ada King, Countess of Lovelace, the first female computer programmer.
The second major breakthrough in the design of computing machines in the 19th century may be attributed to the American inventor Herman Hollerith. He was concerned with finding a faster way to compute the U.S. census, which in 1880 had taken nearly seven years. Therefore Hollerith invented a method, which used cards to store data information which he fed into a machine that compiled the results automatically. The punch cards not only served as a storage method and helped reduce computational errors, but furthermore significantly increased speed.
Of extraordinary importance for the evolution of digital computers and artificial intelligence have furthermore been the contributions of the English mathematician and logician George Boole. In his postulates concerning the Laws of Thought (1854) he started to theorize about the true/false nature of binary numbers. His principles make up what today is known as Boolean algebra, the collection of logic concerning AND, OR, NOT operands, on which computer switching theory and procedures are grounded. Boole also assumed that the human mind works according to these laws, it performs logical operations that could be reasoned. Ninety years later Boole's principles were applied to circuits, the blueprint for electronic computers, by Claude Shannon.
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Punch card, 1801
Invented by Joseph Marie Jacquard, an engineer and architect in Lyon, France, the punch cards laid the ground for automatic information processing. For the first time information was stored in binary format on perforated cardboard cards. In 1890 Hermann Hollerith used Joseph-Marie Jacquard's punch card technology for processing statistical data retrieved from the US census in 1890, thus speeding up data analysis from eight to three years. His application of Jacquard's invention was also used for programming computers and data processing until electronic data processing was introduced in the 1960's. - As with writing and calculating, administrative purposes account for the beginning of modern automatic data processing.
Paper tapes are a medium similar to Jacquard's punch cards. In 1857 Sir Charles Wheatstone applied them as a medium for the preparation, storage, and transmission of data for the first time. By their means, telegraph messages could be prepared off-line, sent ten times quicker (up to 400 words per minute), and stored. Later similar paper tapes were used for programming computers.
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