pascalina

Pascaline, also called the arithmetic machine, is one of the first mechanical calculators designed to perform arithmetic automatically. It was invented by Blaise Pascal in the early 1640s in France to help his father with tax and bookkeeping.

The device uses a set of interlocking gear wheels, each representing a decimal place; the typical version has eight wheels. A user turns a hand crank; this advances the rightmost wheel by one, and carries propagate to the next wheel whenever a wheel completes a cycle from 9 to 0. The wheels display digits through windows and can be set to display a number. The machine performs addition and subtraction; subtraction can be achieved by turning the crank in the opposite direction or by using complements.

Historical context and production: Pascal built a number of machines between 1642 and 1645. The idea aimed to reduce clerical labor for the state. A surviving example from that period is housed in a French museum.

Legacy: The Pascaline influenced later mechanical calculators, including Gottfried Wilhelm Leibniz's stepped reckoner, and is regarded as an early milestone in the development of computing machinery.

Modern status: It remains an important artifact in the study of the history of computing and demonstrates early decimal carry mechanisms and manual digit registration.