Calculator
A calculator is a small special-purpose device for performing numerical calculations. It should not be confused with a calculating machine. 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 for problems where a computation is not complex enough to demand the use of a general-purpose computer. School pupils and students often use calculators for school work. Also, some wrist watcheses contain a calculator (although this was more a fad of the 1980s).
A basic arithmetic calculator
Today calculators are electronic, and are made by numerous manufacturers, in countless shapes and sizes varying from cheap, give-away, credit-card sized models to more sturdy adding machine-like models with built-in printers. Only a very few companies develop and make modern professional engineering and finance calculators; the most well-known are Casio, Hewlett-Packard (HP) and Texas Instruments (TI). Such calculators are good examples of embedded systems.
In the past, mechanical and clerical aids such as abaci, comptometers, Napier's bones, books of mathematical tables, slide rules, adding machines, or combinations thereof, were used for serious numeric work, and the word "calculator" denoted a person (most often female) who did such work for a living using such aids as well as pen(cil) and paper. Needless to say, this semi-manual process of calculation was tedious and error-prone.
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2 History 3 Trivia 4 See also 5 External links |
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 an 8 – 10 digit 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 modern calculators are programmable, can display graphics, and include features of computer algebra systems.
TI-85 graphing calculator
In 1954, IBM demonstrated a large all-transistor calculator. In 1957, IBM released the first commercial all-transistor calculator (IBM 608). The first hand-helds, as opposed to desktop calculators, went on sale in 1970 with models from Sharp and Canon, weighing around 1.7 lb (770 g).
The first pocket-sized model, the 901B measuring 5.2 by 3.0 by 1.5 in (131 by 77 by 37 mm), came out in the fall of 1971 from Bowmar, with four functions and an eight-digit red LED display, for $240, while in August 1972 the four function Sinclair Executive became the first slimline pocket calculator measuring 5.4 by 2.2 by 0.35 in (138 by 56 by 9 mm) and weighing 2.5 oz (70g). It retailed for around $150 (GBã7979).
The first with scientific functions was the 1972 HP-35 from Hewlett Packard (HP); it, along with all later HP engineering calculators, used reverse Polish notation (RPN) (where a calculation like 6 – 2 is performed by pressing "6", "Enter", "2", and "–", instead of algebraically; "6", "–", "2", and "=").
Most common among early scientific calculators was the TI-30 from Texas Instruments (TI). The first programmable hand-held calculator was the HP-65, in 1974; it had a capacity of 100 instructions, and could store and retrieve programs with a built-in magnetic card reader. A year later the HP-25C introduced continuous memory, i.e. programs and data were retained in memory during power-off. In 1979, HP released the first alphanumeric, programmable, expandable calculator, the HP-41C. It could be expanded with RAM (memory) and ROM (software) modules, as well as peripherals like bar code wands, cassette tape and floppy disk drives, paper-roll printers, and miscellaneous communication interfaces (RS-232, HP-IL, HP-IB).
Monroe mechanical digital calculator
The two leading manufacturers, HP and TI, released steadily more feature-laden calculators during the 1980s and 90s. At the turn of the millennium, the line between a graphing calculator and a PDA/ handheld computer was not always clear (forgetting the keyboard for the sake of the argument), as some very advanced calculators such as the TI-89 and HP-49G could differentiate and integrate functionss, run word processing and PIM software, and connect by wire or IR to other calculators/computers.
In March 2002, HP 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 range in particular had an extremely loyal customer base. Nevertheless, HP restarted their production of calculators in late 2003. The new models, however, reportedly didn't have the mechanical quality and sober design HP's earlier calculators were famous for (instead featuring the more "youthful" look and feel of contemporary competing designs from TI).
The business calculator HP-12C is still produced. It was introduced in 1981 and is built until today with nearly no changes. In 2003 several new models were released, including an improved version of the HP-12C, the "HP-12C platinum edition". The continuing success of this outwardly simple professional calculator indicates that the tech-savvy market of today still appreciates a 'no-nonsense' problem-solving product. This clearly shows a preference difference between the professional business user segment and the student-driven market of graphing calculators.
The word "calculator" is occasionally used as a pejorative term to describe an inadequately capable general-purpose microcomputer. The synonym of this meaning is "bitty box", as discussed in the Jargon file.
Electronic calculators
History
Trivia
See also
(Mechanical calculators)
(Electronic calculators)
External links