The Difference Engine
The Difference Engines were calculators designed by Computer Pioneer and Mathematician, Charles Babbage.
Babbage began in 1821 with Difference Engine No. 1, designed to calculate and tabulate polynomial functions. The design describes a machine to calculate a series of values and print results automatically in a table. Integral to the concept of the design is a printing apparatus mechanically coupled to the calculating section and integral to it. Difference Engine No. 1 is the first complete design for an automatic calculating engine. |
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The Analytical Engine
Babbage conceived this idea in 1834. The Analytical Engine has many essential features found in the modern digital computer. It was programmable using punched cards, an idea borrowed from the Jacquard loom used for weaving complex patterns in textiles. The Engine had a 'Store' where numbers and intermediate results could be held, and a separate 'Mill' where the arithmetic processing was performed. It had an internal repertoire of the four arithmetical functions and could perform direct multiplication and division. It was also capable of functions for which we have modern names: conditional branching, looping (iteration), microprogramming, parallel processing, iteration, latching, polling, and pulse-shaping, amongst others, though Babbage nowhere used these terms. It had a variety of outputs including hard-copy printout, punched cards, graph plotting and the automatic production of stereotypes - trays of soft material into which results were impressed that could be used as molds for making printing plates.