calculators
INTRODUCTION
Electronic, electromechanical electronic devices that perform mathematical operations automatically are referred to as calculators. Calculators perform functions that perform the most basic Arithmetic functions, including subtraction, division, and multiplication. Many are also capable of performing more complex calculations, such as regular and inverse trigonometric function ( see trigonometry). Few technological innovations in recent years have had as significant an influence on our daily lives as the handheld or pocket, electronic calculator. These calculators are used to cut down on time and decrease the possibility of making mistakes and can be found in places where you need to be able to use numbers frequently, in office spaces, in banks, stores and laboratories, in schools, and in the homes of people.
The early calculators were mechanical: they carried out calculations using machine components like disks gears, drums and drums. They were powered via hand, and later electricity. By the mid-1950s many of these mechanical calculators were replaced with electronic calculators, which contained integrated circuits, in some cases similar to those found in computers--to execute mathematical functions. In reality, the modern electronic calculators of today are actually specifically designed, or even special-purpose computers. They include built-in instruction on how to use certain operations.
As with other processing systems for data, calculators are of two types: analog and digital. Analog calculators are able to work with different physical quantities, such as fluid flow or voltages for instance--and solve mathematical problems through the creation of a physical analogy to the issue. Slide rules, clocks and utilities meters can be examples that are analog calculators. Digital calculators include the tools most often thought of as calculators. They work directly with the numbers or digits. They function by counting, listing while comparing and then rearranging these numbers. A common set of digital calculators include adding machines, cash registers as well as handheld or desktop electronic calculators.
PRINCIPLES OF MECHANICAL CALCULATORS
The fundamental part of all mechanical calculators includes a set numeral-adding wheels. In a key-driven mechanical calculator (and in most others) they can be seen through a row of small windows that are located on the front on the front of your machine. Each wheel has the numerals from 0 to 9 engraved around the edges. Beneath each wheel is a column of keys with identical digits. Depressing the number 1 key in a column turns its numeral wheel one step; depressing the number 2 key rotates the wheel twice; and the cycle continues. When the 1 and 2 keys are pressed consecutively each time, the wheel is moved forward one step, and then two moresteps, finally signalling three. A column of numbers may be added rapidly by entering the numbers into the keyboard and seeing their sum in the windows. Mechanisms that lock the numeral wheels automatically enable carrying overs. Multiplication is carried out by repeating addition. Subtraction is achieved through indirect methods and division is done by repeated subtraction.
PRINCIPLES OF ELECTRONIC CALCULATORS
The functions of electronic calculators are accomplished by integrated circuits -- tiny arrays made up consisting of thousands, even millions, of transistors. They contain permanent instructions for addition to, subtraction, multiplication, division and (in more advanced calculators) other functions. The numbers that are entered by the user are briefly stored in addresses or locations, within the memory known as random-access (RAM) that contains room for the numbers entered and created at any time by the calculator. The numbers that are stored in these addresses are then processed by circuits, which contain the instructions for mathematical operations.
HISTORY
The oldest tool for calculating is the abacus, which has been in use for a number of many thousands of years. It's composed of movable, counters placed on a marked board or strung over wires. The first version of the slide rule often regarded as the first ever successful analog calculator was invented in 1620, with the help of the English mathematician Edmund Gunter. This rule initially used to divide or multiply numbers by subtracting or adding their logarithms. Then it was possible to make use of slide rules in order to extract square roots, and in certain cases, to calculate trigonometric function and logarithms.
MECHANICAL CALCULATORS
The first digital mechanical calculator, which was the predecessor to the modern calculator was an arithmetic machine designed by French mathematician Blaise Pascal in 1642 ( see Pascaline). Later in the 17th century Gottfried Wilhelm Leibniz created a more sophisticated model of the machine that Pascal had designed. It used a shaft with more and longer teeth fixed on the shaft and a cogwheel that had 10 teeth. The edges of the cogwheel was displayed as a dial. It was marked with the numbers 0 to 9. When the cogwheel was positioned in certain directions along the shaft and then turning the shaft the shaft, two numbers could be added. To multiply two numbers it was necessary to rotate the shaft several times. Subtraction was accomplished via turning the shaft backward while division was done through subtraction repeated.
In 1878 W.T. Odhner came up with the idea of the pin wheel. When a number was set on a machine with this device, the number of pins were raised by wheels on the primary shaft. When the shaft was turned, these pins joined with cogwheels, whose rotations gave answers to the question similarly to the way they did the cogwheels in Leibniz's machine. This invention of the pin-wheel made it possible to construct sleeker and easier to drive machines.
The first commercially successful key-driven calculator, later called the Comptometer was invented by Dorr Eugene Felt in 1886. Key-driven calculators could be operated very quickly and were frequently used in offices. For a specific type of key-driven calculator, known as key-set machines, the number keys were first depressed, or cocked. After that, turning a crank or beginning an engine--transferred the numbers put into the keyboard to the wheels for numerals. The principle of key-set was employed for calculating machines that printed their results on paper tape since it was impossible to control printers directly using the keys.
The first successful commercially-produced rotary calculator was invented by Frank S. Baldwin and Jay R. Monroe in 1912. The first rotary calculators were equipped with a rotary device that transferred numbers from the keyboard into the adding-wheel unit. Since the rotary drive lent itself to high-speed repeating subtraction and addition the machines were able to be able to multiply and divide extremely quickly and even automatically.
Special-purpose mechanical calculators consist of the cash register. It was invented in 1879 , by James Ritty, a storekeeper in order to guarantee the honesty of his clerks. The first bookkeeping machine, an adding-printing device--was made in 1891 with the help of William S. Burroughs, one of the bank's clerks. Punch-card machines, originally used to regulate the operation of weaving machines, were made to adapt to processing information early in 1880s. Herman Hollerith of the United States Bureau of the Census. They read information from cards whose patterns of holes represented numbers as well as letters.
ELECTRONIC CALCULATORS
Technology advancements in the 1940s and 1950s made possible the invention of the computer and the electronic calculator. Electronic desktop calculators that were first introduced in the 1960s, were able to perform the same function as rotary calculators but they were without moving parts. The development of miniature electronic devices that used solid state technology brought a series of electronic calculators with much more functions and faster performance than their mechanical predecessors. Today most mechanical calculators have been replaced with electronic models.
These modern handheld electronic calculators can perform not only addition, subtraction, multiplication and division, but can deal with square roots, percentages, and squaring. All this is accomplished by pressing the appropriate key. press. The data entered as well as the result displayed on a display using or light emitting diodes (LEDs) or liquid-crystal display (LCDs).
Special-purpose calculators have been developed for use in business, engineering as well as in other fields. Some of them are able to perform a series of tasks similar to those done by larger computers. Advanced electronic calculators are able to be programmed using complex mathematical formulas. Some models employ interchangeable preprogrammed software modules with thousands or more of program steps, but the required data needs to be entered manually. Many units have a built-in printer, or an optional one with graphing capabilities, while some models can draw mathematical equations. A lot of calculators have basic computer games that can be played on the calculator's display screen. In fact, the distinction between calculators and portable digital assistants (PDAs), and portable computers has been blurred because all of these devices now typically use microprocessors.
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