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Elrolution and Historv of computers - chapter 1

1. lntroduction:

ln the modern life, no one can think without computer. Computer has become very essentialthing in

our life. Todiy computer is used not only for calculating but for many other activities. For example

computerized telephone, switching centre's control traffic of millions of calls and keep line of

communication untangled, super market scanner that calculates the bill and keep the inventory qorrect,

Automatic teller machines ( ATM) that controls the bank transaction anywhere in the world.

From where this technology has come from? So it is important to understand their growth.

The development of computer from early device to latest computer is classified in to the below category

. Mechanical calculating device

r Electromechanicalcalculating

r Electronic computer

2. Mechanical calculatins devices:

They are classified as below

. Manualcalculatingdevice

. Semi automatic calculating device

3. Mechanical calculating devices

l. Manual calculating device

a. Abacus: This is the first manualcalculating device developed around 3500 BC. lt is rectangular frames

with number of rods. There are 17 rods in abacus. The horizontal line is called bar. Above the bar there

is one bead and below the bar there are 4 beads.

On the bar there are 5 points. From middle to left side called positive side and middle to right side is

called negative side. When the beads touch the baronly, it has value. The middle point is called unitpointorone'srods. lnone'srod,fromdownif onebeadtouchesthebar,thentheanswerisone. lf two

touches the bar, then the value is two. The upper bead has the value 5.

Next to one's rod is ten's rod in the left side. Then 100's rod, 1"000's rod.

We can calculate addition, subtraction, multiplication, division and square root easily using abacus

b. The Napier bones:

r lt is used in 17th centuryr We can calculate multiplication, division even square rooJ and power.

r lt has rectangular strip of wood or bones with figures marked on one side.

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Each rod was divided in ten squares.The top square was a digit from O to 9The square below has multiple of digits

Thesedevicescoulddomostofthecalculationsbyitself(automatic)

r First semiautomatic mechanical device developed by Braise pascal and known as pascal,sPa sca line

' Blaise Pascal is the son of a French tax collector invented this to help his father.r He invented this called as numeric wheel calculator.o He used g movable dials to calculate g digit numbers.o The wheel is numbered from o to 9 and they are arranged in rows as 1,s , L0,s , L00,s ect.' rf one's wheer compretes one revorution, 10,s wheer wiil move one unit.' The disadvantage in this machine is there is rimitation to addition

b.Leibnitz Machine;

r This was invented in 1673 by a German mathematician and philosopherGottfried wilhem vonLeibn itz

' This was developed for addition , multiplication, division and subtr-actionr Multiplication and division was done by shift mechanism brought about by series of slides.r ln the base -ten system, when a digit is multiplied with r.0, shifts:one place to left and dividing adigit with 10 , shifts one place to right. j '

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' This is used for controiling the weaving to make the comprex pattern easyo He used punched card to control the movement of threads by prese4ce or absence of hole inthe cardsr Punched card stored the instruction on the punched card.. The presence and absence of holes are like binary system

d.Difference eneine: ( 1g22)

r charles Babbage proposed a machine to compile mathematicaltable called difference engine.. lt was powered by steam and was long as locomotiver rt courd have stored program and carcurate and print resurt automaticailyr The machine was never compreted due to mechanicar difricurties

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e. Analvtical eheine (1832)

After working on difference engine for 10 years, the Babbage inspired to begin work on firstgeneral purpose computer which is called analytical engine.It is a steam powered engine.It consists of 5O,O0O components

r rt's basic design is input, process, store and finaty wit get the output.o we can store memory 'o0o

numbers up to 50 decimar digits rong.o lt contained a millwith control unit that allowed processing instruction in any sequence andoutput device to produce printed output.r He barrowed idea of punched card to encode the machine instruction from theJacquard loomr lt does not perform one mathematicaltask. But difterent kinds of calculation

f.Punched card: 1gg9

r An American inventor Herman Hollerith used Jaquard room concept for calculating.' His task was to find a faster way to compute the US censusr ln 1990, it took 7 years to complete the US census.o Due to increase in population, the Bureau feared that it would take more than 10 years to countthe latest populationr Herman used punched card to calculate the US census an& completed within 3 years.'

i"T:r:'nch on a card represented one number and combination ottwo prn.r,u, represent on

. 80 characters can be stores in a single card. :r He brought this punched in to the business world and found Tabulaiing machine company in1896 and rater it became rnternationar Business machine ( rBM)in;;;i,.0'"'"'

5. Electromechanical catculatine

a. Markt: (t937 _ L9441

r Howard H'Aiken a Harvard engineer working with IBM , developed an all electroniccalculator by 1944r The purpose of the computer is to create batistic chart for US navyr lt was about half as long s footballfield and contains about 500 miles of wires.r lt was commonly referred was, an electronic relay computer.r rt used electromagnetic signar to move the mechanicar parts.r lt was slow ( it took 3 to 5 seconds for one calculation)r rt is infrexibre but it perform basic arithmetic and more complex equation

5. Technological Advancement

r ln 1898 ' Valdemer Paulson developed recording devices consisting of tapes and drums thatstored electrical info rmation

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Class IX - CHAPTER 1

. Lee de forest, in 1906, invented thermionicvalves called asvacuum tubes. lt switch electricalsignal electronically

r Alan Turning a British mathematician established theoretically that a complex problem having a

logical solution can be split in to a set of simple steps and can be solved easily. All moderncomputers works on this principle.

. Claude Shannon, en electrical engineer showed an electronic switching circuit could be used toperform logical and arithmetic operation. He used Boolean algebra for the first time.

7. Electronic computer: classified in to various generation on the basis of technical development

a.ABC { 1937 - 1938) : Atonsoft Berrv computer.

r This is the first electronic computer used vacuum tubes in the place of electromechanical relaysr lt was special purpose computer.r During Second World War, they planned todevelopthe computerto help in designing and

coding/ decoding of rnessages.

. By 1941, German Engineer Konared zuse had developed a computer called Z3 TO DESIGN Aeroplane and Missiles.

r ln 1943 , the British completed a secret code breaking computer called colossus

First Generation Computers: (1946 - 195.8)

ENIAC (1939 - 1946) : Electronic Numerical lntegrator and computer

r lt was developed by John Presper Eckert and John W.Mauchly.ThiswasconsideredasthefirstelectronicgeneralpurposecomputerI This consists of 18,000 vacuum tubes, 7O,AOO resistors, and 5 million solder joihts. This computer consurned 160 kilo watt of electrical power.r This is 1000 times faster than MARK I

. This can add two large number in 200 Micro seconds where as MARK lcan calculate in 5 seconds

John Von Neumann a mathematician at Princeton University suggested a distinct improvement in1945

r Use of binary number system to store data and instruction in the computer memoryseq uentia lly

r Use a program to process both data and instructions so that execution will be automatic

EDSAC (1947 - 1.949) : Electronic Delay Storage Automatic Computer

o lt was designed by professor M.Wilkes of Cambridge University and was completed in 1949r ln this, the program was fed into the storage unit by means of paper taper lt uses vacuum tubes and was slightly faster than ENIAC.

o lt was not binary but was the first stored - program electric computer.

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EDVAC ( 1949): Electronic discrete Variable Automatic computer

. Von Neumann designed in 1949 with a memory to hold both a stored program as well as data.

. The key element in this computer was control processing unit which allows all the computerfunctions to be coordinated through single source.

UNIVAC I ( 1951) - Universal Automatic Computer

r ltwas built by Rernington Rand, became one of the commercially available computers.r US census Bureau and the General Electric Owned UNIVAC's

Characteristics of First Generation computers:

. Used Vacuum tube and a magnetic drum for storage

. Operating lnstructions were made for a specific task for which the computer was used.

. Each machine has separate binary code program called machine language

Other first eeneration computers:

MARK ll, MARK ilt, UNTVAC il, BURROUGHS

Second Generation Computers ( 1956 - 19631

This computer used transistor and Magnetic core memory. So this computer was smafler, faster, morereliable and more energy efficient

Featu res:

1. They used machine language with assembly language allowed abbreviated programming codes

to replace long, difficult binary codes.

2. They also contained all the components like printers, tape storage, memory, operating systems,and stored programs

3. The high Sophisticated language COBOL and FORTAN came into common use during this period

Exarnples of Second generation computers:

UNIVAC III, 4OO AND 8OO SERIES, B 5OOO, CDC 1604

Third Generation Computers (1964 - 1971)

Jack Kilby an engineer with Texas lnstruments developed lC - integrated circuit in 1-958 whichconsists of three electronic components. Laterthey fixed more components in the chip and called as

semiconductor.

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Characteristic of third Generation:

1-' lntegrated circuit used and as result the computer became small2' Operating system was used to run the machine with different proBrams at one time with a

central program that monitored and coordinated the computer's memory3. lmprovement in magnetic core and magnetic disks and main memory enlarged4' Output and input device come to the market. optical scanner, magnetic ink character tape ,

video display , and graph plotter came to the market

Eg: system 360, system 370, UNTVAC 1100, pDp-11

Fourth Generation Computer:

I lntegrated circuit (lC)are mostly used in this and the size of the computerwas reducedr LSI - Large Scale lntegration could fit hundreds of components onto one chip.o ln 1980 a very large scale integration (VLSI)squeezed hundreds of thousands of components

- in one chipo Ultra large scale integration (ULSI) squeezed millions of components into one chipo This helps to reduce the size as well the cost of the computero lntel 4004 chip was developed and all the components of a computer (CpU, Memory &

lnput/output control) were assembled on one chip and it is called as Microprocessor. Due tothis greater computing power, large memory was developed. personal and home computersare the examples ;l

r Thiscomputer is more powerful and useci to link into the network and share memory,software, information and communicate with each otherthrough localarea network (LAN)

or telephone line.r lnternet can connect all the computer through worldwide into a single network of

information

' ThecomputernetworkisusedtosendEmails bytypingtheEmail address intheinternetand send messages throughout the world

Fifth Generation computer:

r Fourth generation computers mainly focused on changing the values to transistor and then it tolC which made the computer smaller and high speed. But this cannot think

' Fifth generation computers are expected to fulfillthis requirement and it is called as supercom puter.

' This will have high storage capacity & high speed and can do decision making like human beingr This new development of implementing the human thought process is called "artificial

lntellige nce". There will be new style of programming and hardware for it.

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