Calculator 

A calculator is a small special-purpose device for performing numerical calculations. Nowadays many people always have a calculator with them as part of their mobile phone and/or personal digital assistant. Engineers and accountants often make use of calculators, where a computation isn't complex enough to demand the use of a general-purpose computer. Children often use calculators for school work. Some watches contain a calculator.

Today calculators are electronic, but in the past mechanical and clerical aids such as slide rules, abaci, books of mathematical tables and Napier's bones were used, and a "calculator" was a person who made calculations.

Today most calculators are handheld microelectronic devices, but in the past some calculators were as large as many of today's computers. The first mechanical calculators were mechanical desktop devices, which were soon replaced by electromechanical desktop calculators, and then by electronic devices using first thermionic valves, then transistors, then hard-wired integrated circuit logic.

A pocket calculator is a small battery-powered or solar powered electronic digital computer made possible by integrated circuit and semiconductor technology. Typically they are limited to a single-number display and a few basic functions of arithmetic, but some modern ones have more of the features of a general-purpose computer. Pocket calculators rendered the slide rule obsolete.

Calculators vary in their capabilities. Some are limited to only basic arithmetic; others support trigonometric and other mathematical functions. The most advanced are programmable and graphing calculators and include features of computer algebra systems.

The first hand-held, as opposed to desktop calculators, went on sale in 1970 with models from Sharp and Canon, weighing around 1.7 lb. The first pocket-sized model came out in 1971 from Bowmar[?], with four functions and an eight-character red LED display, for $240.
The first with scientific functions was the 1972 HP-35[?] from Hewlett Packard; it, along with all later Hewlett Packard calculators, used Reverse Polish Notation. The most common early scientific calculator was the TI-30[?] from Texas Instruments.

The line between a graphing calculator and a handheld computer[?] isn't always clear, as some advanced calculators such as the TI-89 and TI-92[?] can differentiate and integrate functions, run word processing software and can even connect to the Internet.

In March 2002, Hewlett Packard announced that the company would no longer produce calculators, which was hard to fathom for some fans of the company's products; the HP-48[?] in particular had an extremely loyal customer base. Nevertheless HP continued producing calculators. But the latest models don't have the mechanical quality HP's older calculators were famous for.

The business calculator HP-12C[?] is still produced. It was introduced in 1981 and is built until today with nearly no changes. For 2003 several new models were announced, including an improved version of the HP-12C, the "HP-12C platinum edition".

The word "calculator" is occasionally used as a pejorative term to describe an inadequately capable general-purpose computer, as discussed in the Jargon file.

We need information on history of calculators, early mechanical calculators, etc...

See also: slide rule, abacus, adding machine , List of calculators

External Links

• The Museum of HP Calculators [1] (http://www.hpmuseum.org)
• Early Calculators [2] (http://www.hpmuseum.org/prehp.htm)
• http://www.ti.com/corp/docs/company/history/calc.shtml