..... Click the link for more information. is also a calculator but performs other functions as well.
Mechanical and Electromechanical Calculators
Early devices used to aid in calculation include the abacus abacus (ăb`əkəs, əbăk`–), in mathematics, simple device for performing arithmetic calculations.
..... Click the link for more information. (still common in E Asia) and the counting rods, or "bones," of the Scottish mathematician John Napier Napier, John, 1550–1617, Scottish mathematician. He invented logarithms and wrote Mirifici logarithmorum canonis descriptio (1614), containing the first logarithmic table and the first use of the word logarithm.
..... Click the link for more information. . The slide rule slide rule, instrument for making numerical computations and readings, the results of which may be read easily and quickly after performing simple mechanical manipulations.
..... Click the link for more information. , invented in 1622 by William Oughtred, an English mathematician, was widely used to make approximate calculations, but it has been replaced by the electronic calculator. In 1642, Blaise Pascal Pascal, Blaise (blĕz päskäl`), 1623–62, French scientist and religious philosopher.
..... Click the link for more information. devised what was probably the first simple adding machine using geared wheels.
In 1671 an improved mechanism for performing multiplication by the process of repeated addition was designed by Gottfried W. von Leibniz Leibniz or Leibnitz, Gottfried Wilhelm, Baron von
..... Click the link for more information. . A machine using the Leibniz mechanism was the first to be produced successfully on a commercial scale; devised in 1820 by the Frenchman Charles X. Thomas, it could be used for adding, subtracting, multiplying, or dividing. A mechanism permitting the construction of a more compact machine than the Leibniz mechanism was incorporated into a machine devised late in the 19th cent. by the American inventor Frank S. Baldwin. Later the machine was redesigned by Baldwin and another American inventor, Jay R. Monroe. At about the same time, W. T. Odhner of Russia constructed a machine using the same device as Baldwin's. Charles Babbage Babbage, Charles (băb`ĭj), 1792–1871, English mathematician and inventor.
..... Click the link for more information. , an English mathematician, and William S. Burroughs, an American inventor, also made important contributions to the development of the calculating machine.
Early mechanical adding machines were equipped with a keyboard on which numbers to be added were entered, a lever to actuate the addition process, and an accumulator to display the results. A full keyboard consisted of 10 columns of keys with 9 keys in each column, numbered 1 through 9. Each column could be used to enter a figure in a particular decimal place so that a number up to 10 digits long could be entered; if no key was pressed in a given column, a zero was entered in that decimal place. The lever was pulled in one direction when a number was to be added and in the opposite direction when it was to be subtracted. The accumulator was a set of geared wheels, each corresponding to a decimal place and having the digits 0 through 9 printed on its circumference. When a given wheel made a complete rotation, the next wheel was advanced by one digit. The mechanical adding machine remained essentially the same until the mid-1960s, with improvements consisting of motors to actuate additions and subtractions and mechanisms to print out results on a paper tape.
Electronic Calculators
Electronic calculators, which became available in the early 1960s, at first were merely faster and quieter adding machines. The invention of the microprocessor and advances in integrated-circuit technology made small, but highly sophisticated, calculators possible, and by the mid-1970s they were in wide use. Simple calculators perform only the basic four functions of addition, subtraction, multiplication, and division. More sophisticated calculators can perform trigonometric, statistical, logarithmic, and other advanced calculations.
Some electronic calculators are actually small computers with limited memory and programming capabilities. Some of these programmable calculators can accept plug-in semiconductor memory cards or programming modules for special applications, such as financial calculations, unit, currency, or number-system conversions, or engineering calculations. Others are also available that include nonmathematical functions such as data storage and schedule organizing. The personal digital assistant, a hand-held device optimized as an organizer with communications capability and accepting handwritten input, is a bridge from calculators to full computer function.
Early electronic calculators had numeric displays made from light-emitting diodes (LEDs). They have been supplanted by liquid-crystal displays (LCDs), whose lower power consumption helps to reduce battery drain. Some calculators use an LCD readout to provide a graphic, as well as numeric, display. CMOS, or complementary metal-oxide-semiconductor (see integrated circuit integrated circuit (IC), electronic circuit built on a semiconductor substrate, usually one of single-crystal silicon. The circuit, often called a chip, is packaged in a hermetically sealed case or a nonhermetic plastic capsule, with leads extending from it for
..... Click the link for more information. ), technology is also preferred for battery-operated models because of its low-power requirements. Some calculators are powered by solar cells solar cell, semiconductor devised to convert light to electric current. It is a specially constructed diode , usually made of silicon crystal. When light strikes the exposed active surface, it knocks electrons loose from their sites in the crystal.
..... Click the link for more information. in ordinary room light.
Bibliography
See B. Randell, The Origins of Digital Computers: Selected Papers (1982); J. P. Haney, Calculators (3d ed. 1985).
calculator
Machine for performing arithmetic operations and certain mathematical functions automatically. Blaise Pascal devised a digital arithmetic machine in 1642. By the late 19th century, such machines had become smaller and easier to use, and desktop machines appeared in the early 20th century. Electronic data-processing systems in the mid-1950s led to the obsolescence of mechanical calculators. Miniature solid-state devices ushered in calculators that could perform mathematical functions in addition to basic arithmetic, and also store data and instructions in memory registers, providing programming capabilities similar to those of small computers.
calculator
A machine that provides arithmetic capabilities. It accepts keypad input and displays results on a readout and/or paper tape. Unlike a computer, it cannot handle alphabetic data.
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| The First Handheld Calculator |
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| In 1967, Texas Instruments introduced the first handheld calculator. The opened unit in the picture shows the paper tape used as output. (Image courtesy of Texas Instruments, Inc.) |
calculator
calculator [′kal·kyə‚lād·ər]
| calculator - bitty box |
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