calculators
INTRODUCTION
Electronic, electromechanical electronic, or electronic devices that do mathematical calculations automatically are called calculators. Calculators perform calculations using the standard Arithmetic operations--subtraction, addition division, and multiplication. Many are also able to perform more complex calculations, like habitual and inverse trigonometric calculations ( see trigonometry). Few technological innovations in recent years are having such a significant influence on the daily routine as the handheld, or pocket, electronic calculator. These calculators are utilized to save time as well as to decrease the likelihood of making mistakes and are found wherever there are people who frequently deal with numbers - in offices, retail stores, banks, schools, laboratories, and even at home.
The first calculatorswere mechanical: they performed their computations using machine components like disks drums, and gears that were powered via hand, and later electricity. In the late 1950s, a lot were mechanical calculators were being replaced by electronic calculators, which contained integrated circuits--in certain cases, similar to those found in computers--to do mathematical functions. In reality, the modern electronic calculators nowadays are purpose-built, or special-purpose computers. They are equipped with instructions that tell you how to conduct certain operations.
As with other computing systems, calculators are of two types: analog and digital. Analog calculators operate with variables in physical quantities, like fluid flow or voltages for instance. They also solve math-related problems by creating physical analogies to the issue. Clocksand slide rules and utility meters are all examples from analog calculators. Digital calculators include the tools most frequently thought of as calculators. They directly deal with numbers or digits . They work by counting, listing while comparing and then rearranging the digits. Common digital calculators include cash registers, adding machines and handheld or desktop electronic calculators.
PRINCIPLES OF MECHANICAL CALCULATORS
The fundamental part of all mechanical calculators is a set of numeral-adding wheels. In a key-driven mechanical calculator (and in many other models) they are visible through a row of windows at the top of the device. Each wheel is adorned with the numbers of 0 through 9 around the edges. Behind each wheel, there is a column of keys with the same numbers. Pressing the number 1 key in a column spins the numeral wheel one step. pressing the number 2 key will rotate the wheel for two steps, and that goes on. When the 1 and 2 keys are used in sequence, the wheel advances one step, then two moresteps, finally signalling 3. This means that a column may be added rapidly by typing the numbers in the keyboard and then reading their totals in the windows. Mechanisms that lock the numeral wheels automatically allow for carryovers. Multiplication is performed by repeated addition. Subtraction is achieved through indirect methods and division is accomplished by repeated subtraction.
PRINCIPLES OF ELECTRONIC CALCULATORS
The operations of electronic calculators can be performed using integrated circuits, tiny arrays consisting of thousands, millions of transistors. These circuits are equipped with permanent instructions for subtraction, subtraction, multiplication, division as well as (in more sophisticated calculators) additional functions. The numbers input by the operator are briefly stored in addresses or places, in the memory known as random access (RAM) which is a storage space for the numbers used and created at any moment through the computer. The numbers stored in these locations are then processed by the circuits, which contain the instructions for the mathematical operations.
HISTORY
The most ancient calculating aid is the abacus, which has been in use for a number of decades. It is comprised of movable counters, which are either placed on a marked board or hung on wires. An early version of the slide rule, widely regarded as the first successful analog calculator, was created in 1620 in 1620 by English mathematician Edmund Gunter. The slide rule was originally employed to multiply or divide numbers by subtracting or adding their logarithms. Then it was possible to utilize slide rules to determine 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 algebraic machine devised by French mathematician Blaise Pascal in 1642 ( see Pascaline). In the 17th century, Gottfried Wilhelm Leibniz created a more advanced variation of Pascal's machines. It was based on a shaft that had gradually longer teeth that were fixed to the shaft and a cogwheel that had 10 teeth. The cogwheel's edge displayed on a dial and was marked with the numbers 0 to 9. The cogwheel was placed in a specific direction along the shaft, and then turning the shaft to rotate it, two numbers could be added. When multiplying two figures by turning the shaft multiple times. Subtraction was made using the shaft turned in reverse while division was done by repeated subtraction.
In 1878 W.T. Odhner invented the pin-wheel. When an amount was set on a machine using this device, the number of pins would be moved up on wheels attached to the main shaft. When the shaft was turned, the pins interlocked with the cogwheels, whose rotations gave the answer to the sum in the same way as did those on Leibniz's machines. The invention of the pin-wheel was what made it possible to design cleaner and more easy-to-drive machines.
The first commercially successful key-driven calculatorlater known as the Comptometer was invented by Dorr Eugene Felt in 1886. Key-driven calculators could be operated quickly and were frequently used in offices. For a specific type of calculator that was driven by keys, referred to as a key-set machine, the number keys were first pressed, or cocked. After that, turning a crank or starting an engine--transferred the numbers that was entered into the keyboard onto the numeral wheels. The key-set concept was utilized in the calculation of machines that printed outputs on paperstape because it was impossible to control printers directly using the keys.
The first commercially successful rotary calculator was developed by Frank S. Baldwin and Jay R. Monroe in 1912. The first rotary calculators incorporated a rotary mechanism to transfer numbers that were set on the keyboard onto the adding-wheel unit. Because the rotary drive lends itself to high-speed repetition of addition and subtraction and division, these machines were able to increase and decrease quickly, as well as automatically.
The special-purpose calculators consist of the cash register. The cash register was invented in 1879 , by James Ritty, a storekeeper to ensure the integrity of his staff. The first bookkeeping device--an adding printing device -- was created in 1891, with the help of William S. Burroughs, an employee of a bank. Punch-card machines, originally used to regulate the operation weaving machines, were made to adapt to information processing through the 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
Developments in electronics in the 1940s and 1950s made possible the development of computers as well as the electronic calculator. Electronic desktop calculators made their debut in the 1960s, were able to perform the similar functions to mechanical calculators but they were without moving components. The introduction of miniature electronic devices with solid-state electronics brought an array of electronic calculators with far more functions and far faster performance than their mechanical counterparts. Today most mechanical calculators have been replaced by electronic models.
The latest handheld electronic calculators can not only perform multiplication, subtraction and division but can handle square roots percentages, and squaring. This is by pressing the appropriate key. pressing. The data that is entered and the final result are shown on a screen with the use of either light-emitting diodes (LEDs) or liquid-crystal screens (LCDs).
Special-purpose calculators were designed for use in engineering, business and other areas. Some of them are able to manage a variety of tasks similar to those performed by larger computer. Advanced electronic calculators are able to be programmed using complex mathematical formulas. Some models are equipped with interchangeable software modules with 5,000 or more program steps, though the necessary information must be entered manually. Many units have a built-in or accessory printer and some even graph mathematical equations. Many calculators come with basic computer games that are played on the calculator's display screen. In reality, the line between calculators as well as personal digital assistants (PDAs), and portable computers has been blurred because all these devices now typically use microprocessors.
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