THE HISTORY OF CALCULATORSt Mechanical, electromechanical, 01' electronic devices

that perform arithmetic operations automatically arecalled calculators. Calculators perform the basicmathematical functions -addition, subtraction,multiplication, and division- and many can also do morecomplicated calculations, such as' normal and inversetrigonometric fttnctions. Few inventions of recent timeshave had such a profound influence on daily life inindustrialized nations as the hand-held, or pocket,electronic calculator. ['hes-e calcu a ors are used to save

time and to reduce the chance of making mistakes and are found wherever people dealfrequently with numbers -in stores, offices, banks, schools, laboratories and homes.

2. The oldest calculating aid is the abacus, wniClíl.has been used for thousands of.years. consists of movable counters placed on a marked board or strung on wires. Anearly form of the slide rule, often regarded as the first successful analog calculator,was developed in 1620 by the English mathematician Edmund Guukr. The slide rulewas originally used to multiply or divide numbers by adding or subtracting theirlogarithms. Later it became possible to use slide rules to extract square roots and, insome cases, to calculate trigonometric functions and logarithms.

;~ The first mechanical digital calculati~g machine -the predecessor of themodern calculator-was an arithmetic machin~ devised by the French mathematician

, Blaise Pascal in 1642. Later in the 17th century Gottfried Wilhelm Leibniz created amore advanced version of Pascal's machine. It used a shaft with teeth fixed along itand a cogwheel with ten teeth. The edge of this cogwheel showed in a dial and wasmarked with the numbers O to 9. When the number 4, for example, was set on the Y[ll>OZÁS

machine, the shaft moved so that only four of the teeth interlocked with the cogwheel.When the shaft was turned once, the cogwheel advanced by four tenths of a revolutionso that the number showing on the dial increased by four. In this way addition wasperformed. To multiply 4 by 5, the number 4 was set on the machine and the shaft wasrotated five times. Figures were carried over by turning the shaft backward, anddivision was performed by repeated subtraction.

4 In 1878 W.T. Odhner invented the pin-wheel. When a number was set on iJmachine using ·lri device-, the correspondmg number of pins was raised on wheels rif~carried on the main shaft. When the shaft was turned, the pins interlocked with thecogwheels, whose revolutions gave the answer to the sum in the same way as did those_in Leibniz's machine. The invention of the pin-wheel made it possible to build neaterand more easily driven machines.

S The first commercially successful key-driven calculator, later called theComptometer, was invented by Dorr Eugene Felt in 1886. Key-driven calculators couldbe operated very rapidly and were widely used in offices. In one kind of keY-driven'lcalculator, called a key-set machine, the number keys were first depressed, or cocked. Prtl<41Then a second action -turning a crank or starting a drive motor- transferred thenumber set into the keyboard to the numeral wheels. The key-set principie was used

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e ating machines that printed results on paper tape because it was not possible: re printers directly from the keys.

~ The first commercially successful rotary calculator 'was developed by Frank S.. and Jay R. Monroe in 1912. Rotary calculators incorporated a rotary

ani m for transferring numbers set into the keyboard to the adding-wheel unit.==-ce the rotary drive lent itself to high-speed repeated addition and subtraction,

- machines could multiply and divide rapidly and automatically.

7 Developments in electronics in the 1940s and 1950s made possible the creatione computer and the electr~ic calculator. Electronic desktop calculators,

. troduced in the 1960s, performed much the same functions as rotary calculators butad virtually no moving parts. The development of miniature solid-state electronice.•.ices brought a series of electronic calculators that were capable of far morenctions and far faster operation than were their mechanical predecessors. Today

mo t mechanical calculators have been replaced with electronic models.

Most modern hand-held electronic calculators can perform not only addition,ubtraction, multiplication, and division but also can handle square roots, squaring,

and percentages when the appropriate key is pressed. The data being entered and thefinal result are displayed on a screen using either light-emitting diodes (LEDs) orliquid-crystal displays (LCDs).

~ Special-purpose calculators have been developed for use in business,engineering, and other fields. Some o Le~ are able to handle sequences of tasksmuch like those done by larger computers. Sophisticated electronic calculators can beprogrammed with complicated mathematical formulas. Some models employinterchangeable pre-programmed software modules capable of 5,000 or more programteps, though the necessary data must still be keyed manually. Many units have a

built-in or an accessory printer, and some can plot data points and print alphabeticcharacters. Some calculators are made with rudimentary cornputer games that can beplayed on the calculator's display screen.

Source: Compton's Interactiue Encyclopedia. Copyright © 1994,1995 Compton's NeiosMedia, Inc.

Exercises

References.Indicate what the following words in italics refer to in the text.

Par. Line Word .Answerl. 1 10 These calculators ... ~0t/O~ ~a.kr:í

2. 2 1 ...which has been ... ~ ~

3. 2 2 It consists ... .~~

4. 4 2 ... this device ... .~h-~

5. 9 2 Some of these... ~;J ~~rlCA' -~S-<.,

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Vocabulary.Circle the appropriate meanings in column B for the words in column A. Take thecontext into account!

ColumnA Column Bpocket a) a small bag for earrying things in, whieh is made of cloth.(par 1, line 9) ~ to take something for yourself, espeeially dishonestly.

e) something that is small enough to put in your poeket.shaft a) a pole or rod which forms the handle of a tool or weapon.(par 3, line 7) ~ a rod of a maehine whieh turns iR sras" te l'a,.¡;¡& pOl11sr SB tg th •.•machine

e) a long, either vertical or sloping, passage through a building or through the ground.reuolution. a) a change in the way a country is governed.(par 3, line¡f) b) a very important change in the way that people do things.

-& ~ one continued circular movement around a fixed point.drive a to provide the power to make a machine operate.(par 5, line 8) b) to travel a distance in a motor vehicle.

c) to force SOmeone or something to do something.

Compound nouns.Circle the head noun and explain the meaning of the following compound nouns.

Par Line Compoun.d noun Meaningl. 3 1 mechanical digital calculating~ch~ n-.~~~

2. 5 1 commercially successful key-driven ~ ~d-f'.'vCJto,.. ~ i$ S·/.IV

3. 6 4 high-speed repeatedcMditi~ tl.A¿dxtn,... w/....td,.. ~J ~ii( 4-1....)'4. >f..-eJ..

4. 7 4-5 miniature sclid-state eleetroni~viC€§) oÚVtCw w~~ ¿lu.:trv~c-l~..t-~ 1-

5. 8 4 light-emitting€d~ 1'~k"odM ptWJ..- ~ 1At-!"

Chronology.Complete the following time line by retrieving key information from the texto

DateI¿,h:>

Event

Development of the slide rule_·-=~.!J/--_~~-=-=:"":':::::":"',r _E~uJ.'S ~t~c;.. ~f/'.t..1642

~' tdJ4"2..

1878

1886

1"12

An advanced version of the mechanical digital calculating machine was ereated{)¡/.Á-fW' j J1'l?n~

Development ofthe rotary calculator by Frank S. Baldwin and Jay R. Monroe

~r -r: ~~c.. ~r~-~ 19408-1950s

1960

Nowadays ,

16I' /In N>'\ ~ 1;~ +ed: "<j~ ~tf..... ~W¿,I' r av....

\,.1* ~~ l~ l~40~ ·-/\i)s-vs. Tfu. t4:f ie~ ~~ ~()..wt ~ f-11¡~j¡.{¿ t~~ ~~. vJlu.v..? ~ tk 1960)?

dLdro,wc.. ~!~ ~.t-4,~

¡~\ ~ ~. to llI-L-

rue I False.Based on information in the text, indicate if the following statements are true (T) orfal e (F).

F~ 1.

o

The Compometer consisted of a set of pins that were raised on wheels and lf 5carried on the shaft.

2. The rotary calculator could divide and multiply automaticaUy due to the key set tf' "-principle that allowed repeated additions and subtractions at high speed.

3. The first mechanical calculators were invented in the course of the 17th 'lf 3century.Special-purpose calculators are similar to computers because they can handle f..,.great task sequences.

5. Jay R. Monroe and Frank Baldwin developed the rotary calculator by the end of ff'the 20th century. Clkr~ of-tL..., ~"-'"'1)Sophisticated electronic calculators have the advantage of permitting a lot of \??functions because they can be programmed with mathematical equations.

7. The pin-wheel was invented~ the second half of the 19th century. ir 4-

o

o 4.

o

o 6.

oComprehension questions

1. Identify a process described in the texto In the space provided, indicate theparagraph number and lis.t the ste.p.s. . .' J~\r3 - l. ~~A~¡.s:H~ ~LkWL-«..cw- l'TlJ

2. TI.... ~ W'<:l\Ie--i +~ s~ ~t.r 01 ~ &....l0"j a....... .::..aa~ v. s'UA-UU.,:3 . .4. '<

2. The purpose of the last paragraph is to:

a) provide a brief definition of special-purpose calculators.® indicate some of the features of special-purpose calculators.e) describe the process ofusing special-purpose calculators.

This text and its actioiiies were coniributed. by Pro(. Yris Casarl ..

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