History of computing

It is difficult to identify any one device as the earliest computer, partly because the term "computer" has been subject to changeable interpretations over time.

Originally, the term "computer" referred to a person who performed numerical calculations (a human computer), often with the aid of a mechanical calculating device. Examples of early perfunctory computing devices included the abacus, the slide rule and arguably the astrolabe and the Antikythera mechanism (which dates from about 150-100 BC). The end of the center Ages saw a re-invigoration of European mathematics and engineering, and Wilhelm Schickard's 1623 device was the first of a number of mechanical calculators constructed by European engineers.

However, none of those devices fit the current definition of a computer because they could not be programmed. In 1801, Joseph Marie Jacquard made an development to the textile loom that used a sequence of punched paper cards as a template to allow his loom to weave intricate patterns automatically. The resulting Jacquard loom was an important step in the improvement of computers because the use of punched cards to define woven patterns can be viewed as an early, even though limited, form of programmability.