1.3 A brief history

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A BRI EF HI STORY

Para 1.3

Data

Instructi ons Process Output

Input

FIGURE 1.1 : DATA PROCESSING

The vari ous i nput and output devices used duri ng the process are discussed i n the co m i ng units.

1.3 A BRIEF HISTORY

Around 4t h cent ury B . C. a si mpl e counti ng ai d was i n ventedi n Babyl oni a ( nowIra q) na med ( Fi g. 1. 3). It was a wooAbacus den rack hol di ng t wo horizontal w ires w it h beads strung onthe m . Nu mbers were represented usi ngthe positi onof beads on the rack. The si mple calcul ati ons were carriedout by appropri atel y pl aci ngthe beads. In 1642, a French mathe matici an and phil osopher Bl aise Pascal FIGURE 1.3 : ABACUS i nvented a calcul ati ng device na med “ Addi ng Machi ne” ( Fi g. 1. 4). It was an i mprove ment over Abacus. It -is

also known as “ Nu merical Wheel Calcul ator” . It uti lized a trai n of 8 movable di als to add su ms of upto 8 fi gures l ong. As one di al t urned co mpl ete revol u ti onit mechanicall yt urne d the next di al. It provi ded a fair degree of accuracy and speed. The first auto mated co m put er was i nvent ed -by

, a pro Charles Babbage fessor of mathe matics at

FIGURE 1.4 : ADDING MACHINE

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Para 1.3

BASI C COMPUTER CONCEPTS AND NET WORKI NG

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Ca mbri dge Uni versity, Engl and, i n1822. Herealizedthat manyl ongcalcul ati ons usuall y consisted of a series of acti ons which were constantl y repeated and hence coul d possi bl y be auto mated. He persuaded the British govern ment to fi nance his desi gnto buil da machi nethat woul dcalcul atetablesforl ogarith ms He desi gned an auto matic calcul ati ng machi ne that he called the ‘ .

Difference Engine

’ . It was stea m powered and full y auto mated. For his contri buti ons i n the fiel d, Charles Babbage is also known as The evol uti on of co mputers can be di vi dedfather of computers. i nto 5 generati ons: 1. First Generati on (1940-1956) : Vacuu m Tubes 2. Second Generati on (1957-1963) : Transistors 3. Third Generati on (1964-1971) : Integrated Circuits (I Cs ) 4. Fourth Generati on (1971- Present) : M icroprocessors 5. Fifth Generati on ( Present and Beyond) : Artifici al Intelli gence

First Generation (1940-1956): Use of Vacuum Tubes The co mputers made and used duri ng the years 1940 to 1956 are believed to be the first generati on of co mputers which used vacuu mt ubes for circuitry and magnetic dru ms for me mory. The size of first generati on co mputers was often enor mous, taki ng up the entire roo m . They were very expensi ve to op erate and i n additi on used a great deal of electricity, generated a l ot of he at, which was often the cause of malfuncti ons. The first generati on co mputers relied on machi nel anguage, thel owest progra mm i ngl anguage, progra mmed i n stri ngs of ‘ 0’ s and‘ 1’ s. It was very difficult totrace and correct the progra m m i ng errors, if any. The exa mples of first generati on co mputers are UNI VAC and ENI AC .

Second Generation (1957-1963): Use of Transistor The second generati on co mputers used Transistors i n pl ace of vacuu mt ubes. The transistor was i nventedi n 1947 but it was usedi n co mputers i n onl y l ate 1950’ s. The transistor was superi or to the vacuu mt ube i n the sense that it made co mputers s maller, faster, cheaper and more energy-efficient. It di dn ’t require a co mplete roo many more. However, even thoughit was ani mprove ment over the vacuu mt ube the transistor still generated a great deal of he at whichso meti me subjectedthe co mputer to da mageitsi nternal sensiti ve parts. Second-generati on co mputers used asse mbl y l anguage for progra mm i ng. So me earl y versi ons of COBOL and FORTRAN were also used by the second generati on co mputers.

Third Generation (1964-1971): Use of Integrated Circuits In 1958, the devel op ment of the i ntegrated circuit (I C) took pl ace but it coul d be usedi n co mputers onl y after m i d of 1960s which brought si gnificant change i n co mputi ng. I Cs used silicon chi ps, called se m iconductors, which drasticall y i ncreased the speed and efficiency of co mputers. As a result, the co mputers beca me s maller i n size as more co mponents were squeezed onto the chi p.

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