11) Computer Theory Notes

8/12/2019 11) Computer Theory Notes

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COMPUTER THEORY NOTES:

Computer meaning

The characteristics of computers

The first computer of the world

The Generations of computers

The basic electronic components of computers

The types of computers

Computer hardware& software


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A) Computer meaning :

Computer is electronic device, used for information processing. Its

accept the instructions by the user with the help of input devices than

stored in its memory, process it next produce the result on output

devices.

Computer can works on I! cycle. I! means Input& !utput"

processing cycle. #howing on down.


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B) The characteristics o computer:

a) Spee!:

Computer can work at an incredible speed. The speed of the

computer is measured in terms of

$illiseconds

$icrosecond

%anoseconds or ico seconds.

The speed of processing is it is accepting million instructions per

second.") Accurac#:

In working being fast computer also accurate, they either give the

correct answer or not at all.

c) Consistenc#:

Computers being machine are highly consistent, they never get

bored too.

!) Automatic:


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Computer can work automatically by itself because once stored on

a ob they carry in until the ob is finished normally without any

human assistance.

e) Storage capacit#:

Today's computer can stored huge amount of data. !nce recorded

a piece of information is never forgotten the storing capacity of

computer measured by (ilobyte, mega byte& gigabyte.

) $%e&i"i%it#:

computer are used not only one thing, it is used toentertainment)movie, song, animation*, account maintaining,

creating letters& letter heads, play games, weather forecasting,

railway reservation counter, aircraft, satellite, studio designing and

sending the information in whole +ord)internet*. & multimedia.

C) The irst computer o the 'or%!:

S% no Nation Year Computer

Name

(nnoator

China -/ bc 0bacus

1 #cotland 23 %apier bones #ir. 4ohn

%apier

5 6rench 2-1 ascaline )ascal

calculator*

$r. 7laise

ascal

- Germen 23 0rithmetic $r. Gatrified


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replica

8ngland 9th

century

:ifference

engine

#ir. Charls

babage

2 ;#0 9-< $ark I =award aikey

C=0>?8# 7070G8 is a father of the computer, professor of

Cambridge university was invented @:I66>8%C8 8%GI%8A in

9thcentury, which is called the first computer of the world.

*) Computer generations:

articulars stgeneration 1nd

generation

5rd

generation

-th

generation

thgenerati

Bear 9"< 99"2- 92"3/ 93"T>0%

, !#C0?

?!G!, C,

CDD,

:atabase

?!G!,

CDD,

:atabase

8lectric /kwEhour less less less 15/watsEho


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consumption

#iFe /x/ feet E1// siFe

of valve

less smaller


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7asic electronic components used inside of the computer

which are reuired to working computer.

,) -accume tu"es:

This component were designed with as Hvalves' also

called as vaccum tubes as basic electronic components

in stgeneration computers

.) Transistors:

Transistors were used an assembly language could usedfor programming, Transistor were used in place of

vaccum tubes as a basic electronic component in 1nd

generation computers. This siFe of transistor was

E1// siFe of valve.

/) (ntegrate! circuits:

IC is a composition of many transistors in integrated

form many transistors integrated in single IC reduced

the siFe & cost of the components, because only one IC

replaced many transistors. IC used for language

6!>T>0%, 0#C0? in 5rdgeneration computers.

0) Micro processor:$icro processor is a integrated form of of entire

electronic circuits along with the components on a

single silicon chip.


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It is used for -th& thgeneration computes.

E) T#pes o Computers:

+e have 1 classifications about computer types.

a) Base! on si1e 2 capa"i%it#:

The computers can be divided in to four categories based on their

siFe & capability.Micro computer:

ersonal computer is known as microcomputer, microcomputer is

very simple & built with only one single IC& only one $icroprocessor.

It is used on schools, home& personal use. !nly one person can operate

at a time.

Mini computer:

$ini computer is advanced than microcomputer in terms of

performance, speed. 0t the most < persons can use simultaneously work

on a single minicomputer is much more than micro computers.

Mainrame computers:

Computers which are big in siFe and faster than minicomputer areknown as mainframe computer. $ore than < persons can work

simultaneously on single mainframe computers.

8x >ailway, airlines etc.


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Super Computer:

#uper computer is specially designed computer built with more

number of processor for particular purpose, it is used special

applications like military, weather fore casting, space, satellite work etc.

0>0$"/// is the first Indian super computer.

") Base! on %o' o inormation2 har!'are:

The basis of flow of information& hardware computers can be

classified 5 categories.

*igita% computer:

:igital computer used 1 digits H/' & H' as the switch can be either

on or off. They can understand only machine language that is in the form

H/' &H'.

Computers which consist of large number of interconnected

switch in IC work on digital electronic techniue are called

digital computer.

Ana%og computer:

0nalog is Greek words which mean @comparing between 1 valuesor 1 uantitiesA. The analog computers number indicated as a result of

voltage& current, like as clock. 0nalog computer worked with electric


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signals. These computers are used control robot, rockets lunching pad

etc,

H#"ri! computer:

The computer which have a characteristic of both digital & analog

computers are called hybrid computer. This is used for robot, pathfinder,

temperature control, C%C machine, computer with multimedia etc.

Computer Har!'are2 Sot'are:


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Har!'are:

Computer is not only one thing, it is integration form many

hardware. =ardware means the visible parts of computer, like monitor,

printer, C;, keyboard, mouse etc. it's all parts helps to working

properly.The parts of computer

Computer in fact is an integration of many parts, each part its

own specific ob that cannot be replaced another part, there

fore it is very important to study the used and working of the

various parts of computer.

0ll these parts classifieds in following as

* Input devices

1* !utput devices

5* C;

a* 0?;b* C;

c* $;

-* #ome important parts


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a+ (nput !eices:

The devices which we used to feed the informationEdata to

computer that device are called input devices.

"+ 3e#"oar!:

The keyboard containing alphabets from 0 to J, & numbers / to 9

& many other function keys )K LMNO&PQRSD*. It is used enter the

textEdata &number &operate other function. There are 1 types of

keyboarda. normal keyboard

b. multimedia keyboard

c+ Mouse:

$ouse is used to operate the system by selecting menus& used to

painting & drawing pictures. Its having a 1"5 buttons on a top, it is used

painting.

There are 5 types of mouse.

a. %ormal mouse

b. !ptical mouse

c. ower mouse

!+ Scanner:#canner is used scan the images, photos &with the help of scanner

we can input alphabets, logos, letter heads in to computer.

e+ 4o#stic5:


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It is used to playing games

+ 6e" camera:

It is used feed our photos to computer.

g+ Output !eices:

The devices that are used to getting the result the processed

information from the computer.

,+ Monitor:

It's like T. !n a monitor we can see which we are typing &

processed data. The siFe of monitor is 3 inches to 9 inches. There

are several types of monitors.

a. 7lack and white monitor

b. color monitor

c. digital monitor

d. T6T monitor

e. C>T monitor

.+ Printer:

rinter paint on result or out put in a color or black.

a. ink et printer ink


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b. :ot"matrix printer power &tape

c. ?aser et printer

/+ Spea5ers:

It is used to listen the music &sound.

%ote C: &6loppy are also using both input &out put device

we have learn about its in memory devices.

/) CENTRA7 PROCESS(N8 UN(T 9C P U)

The information or data is sent to the computer using input

device the dataEinformation is processed in the c p u. =ence c p u can be

termed as the brain of computer

a* 0rithmetic logic unit )0 ? ;*

b* Control unit )C ;*

c* $emory unit )$ ;*

A) A 7 U:

+hen we have to calculator something like 1D1 we apply our

brain similarly the computer will calculate in the 0?; of C;.

This kind of produce of calculating is called @dataprocessingA.

B) Contro% Unit:


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C; is which control all activities by sending signal to

different parts of computer at appropriate time. This enable be

smooth functioning of computer.

C) Memor# Unit:

In computer language memory means storage of all the data

or information is stored in the memory in the forms of / & , that

is /& is called bits. In a memory unit information is organiFed inthe form of cells, each cell can store either / or U the group of


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>0$ is temporary memory unit. It works only when the computer

is switched on, the stored information can be changed, erased or

rewritten, as the data can be accessed randomly to read &write using this

memory.

.) ROM:

>!$ is temporary memoryU the information stored in will not be

last even when the computer is switched off, because the data orinformation stored in >!$ is read only. +e cannot change this

according to our reuirements.

i) Secon!ar# memor#:

This is permanent memory, its stores all the information even

when the computer is switched off. It is also called backup memory. 8x

floppy, hard disk, cd etc.

ii) $%opp# !is5 2!rie:

6lexible & circular plastic plate coated with magnetic oxide, the

data is stored on the floppy. 6loppy drive is reuired to read the floppy.

Two types of floppy

$ini disk .1"inch floppy disk.1 mb.

$icro disk 5."inch floppy disk

.-- mb.


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iii) C* 9compact !is5):

Cd is optical disk, this is circular plastic plate, that it is coated with

highly reflective material the data is recorded on this disk by focusing a

laser beam on surface of the disk. The storing capacity of cd is 2-/

mb. Cd drive is reuired to this which is used to read the cd.

i) Har! !is5:

=: is a group of rounded metal plates mounted one above the

other which is created magnetic material. It can store more dataU the

storage capacity of =: is 1 G7 to 12/ G7.

RPM: )revolution per minute* the speed of rotation of hard

disk while reading & writing is measured revolution per minute.

H*C: hard disk controller

.) Some important parts o computer:

a) Smps:9s'itch mo!e po'er supp%#)

#mps is a main unit that supply reuired electric current to

various circuits and components.

") Coo%ing an:

#mps by on it built fan which exhaust the hot air& keeps the

system cool while working. !ne or more fans are there insidethe system & may have proper functioning.

c) Mother "oar!:


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$other board is made of a special type of plastic, metallic

tracks are attached on this board. +orking of whole

computer system is based on the electronic circuits board of

the computer is called mother board. The micro processor

chip is called as cpu is fixed motherboard & memory

chips)>0$& >!$* are also affixed on the mother board, all

input& output slats )monitor, printer, mouse, keyboard,

floppy, hard disk, cd rom etc.* are also fixed on a same

board& 6:C)floppy disk controller*, =:C)hard diskcontroller*& display adapter card also fixed.

!) Micro processor:

It is made by siliconU microprocessor also called C; is tinny

sure or rectangular chip

e) *isp%a# a!apter car!:

The information displays on monitor is reuired display

adaptercard. It is a small circuit's board fixed in

motherboard.

Types

0. monochromes display cardsingle color old

monitor

b. G0video graphics adapter

c. #G0super video graphics adapter


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Notes:

a. Cd& floppy is using both input, output& memory devices.

b. %ow a day's pen drive is also there.

c. $any other parts ex. T tuner card, ?0% card, cable are

used different purposes.

Computer sot'are:

+hen particular problems is to we solved by the computer. It

necessary to design instructions for the computer to carry out the

assigned task, the art of writing this instruction is called programming.

rogramming is nothing but a set of well defined instructions such set of

program or programming is called software, software cannot be touched

or seen, it is only to make the computer work. There are 1 types of

software.

a* #ystem software or operating software

b* 0pplication software

a) S#stem sot'are or Operating sot'are:This is collection of programming for the management of

computer systemU this program is given by the manufacture of the

computer. 0ll the basic software is called as system or operating system.


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It is essential for any computer without this software no computer

will work or functioning. #oftware communicates between the operator

and system undo & manages the computer computer devices connected

to the computer.

#ystem software is.

:os;%IV

+indows

?inux

a+ *os:

This is single user operating system developed by 7ill gates and

ull 0llen in early in 9


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11) Computer Theory Notes