New Gateway to Computer Science 7

NEW GATEWAY BOOK
to
7
COMPUTER
SCIENCE

VideoWTiuthtorials

Approved by Government of Nepal, Ministry of Education, Curriculum Development
Centre, Sanothimi, Bhaktapur as an Additional Learning Material.

NEW GATEWAY
TO

COMPUTER SCIENCE

7

Authors

Dinesh Adhikari
Dilendra Prasad Bhatt

Laxman Adhikari
Shekhar Poudel

Shubharambha Publication Pvt. Ltd.
Kathmandu, Nepal

Published by:

Shubharambha Publication Pvt.Ltd.

Kathmandu, Nepal
URL: www.shubharambhapublication.com.np
E-mail: shubharambha.publication@gmail.com

www.facebook.com/shubharambhapublication

New Gateway to Computer Science Book-7

Authors : Dinesh Adhikari, Dilendra Prasad Bhatt,

Laxman Adhikari, Shekhar Poudel

Layout Design : Ram Malakar

Video Content : Dinesh Adhikari

Language Editor : Krishna Prasad Regmi

Copyright © : Dinesh Adhikari

Edition : First 2076

: Second 2077

ISBN : 9789937579315

© : Publisher

No part of this book may be reproduced or transmitted by means (electronic,
photocopying, recording or otherwise) without prior written permission from the
publisher. Any breach of this condition will entail legal action and prosecution.

Printed in Nepal

Preface

It has become a fundamental right of children to get computer education. It is
very essential to get basic to advance knowledge about computer education to
compete the future. Nepal government has prescribed the syllabus and course
outline for the computer education from primary to higher secondary level. But
students are not able to get quality education due to the lack of systematic course
book and the computer system in the school. So we have developed the complete series
of computer science.
Along with the evolution of human beings new thoughts, area of knowledge and
technology also developed together. Among the eruptions, ICT (Information and
Communication Technology) is one which has unquestionably become important part
of human beings. A person is not better than a caged pigeon if s/he is far from computer
technology in this century. New Gateway to Computer Science is a complete package
which obviously supports a lot to the students as this is one of the most useful Text Book,
so far available in the market.
This book is completely prepared considering the level of the students. This text has the
various salient features like it focuses on child psychology, pictorial descriptions, video
tutorials, quiz section, practical sections, etc.

How to get video tutorials?
1. Install QR code reader apps on your mobile device (smart phone) from play store.
2. After installation, open the apps from your device.
3. When you open this apps, a camera will appear.
4. Move your camera over the QR code picture (Scan here for video tutorials) that
is provided in your text book.
5. Now QR code reader automatically scans it and displays the link of related video.
6. Touch on the link and open it in YouTube for video tutorials.
Ensure that you have internet connection before scanning the code from the

text book.

It is impossible to acknowledge all who have directly or indirectly encourage me to
prepare this book on this single page. My special thanks goes to the students and teachers
of different schools for their regular interactions during the preparation of this book.
Comments and constructive suggestions are highly welcomed from the readers and
professionals to update this text book.

Dinesh Adhikari
dinesh.nayaghare@gmail.com

Content

Unit 1: Fundamental Knowledge and Skill of Computer 5-148

1. Introduction to Computer ...........................................................................6

2. Historical Development of Computer .......................................................19

3. Generations of Computer ..........................................................................30

4. Types of Computer ...................................................................................39

5. Introduction to Computer Hardware and Software ..................................49

6. Operating System......................................................................................66

7. Word Processing Progra­m- 2010 .........................................................87

8. Spreadsheet Software -2010....................................................................106

9. Presentation Software- 2010 ...................................................................135

Unit 2: ICT, Computer Ethics and Cyber Crime 149-181

10. ICT and Computer Ethics ......................................................................150

11. Computer Virus........................................................................................157

12. Introduction to Computer Networking.....................................................164

13. Introduction to Internet and E-Mail ......................................................172

Unit 3: Computer Number System 182-191

14. Computer Number System .....................................................................183

Unit 4: Computer Graphics and Multimedia 192-217

15. Computer Graphics .................................................................................193

16 .Introduction to Multimedia .....................................................................210

Unit 5: Concept of Computer Programming 218-244

17. Programming Language and Program Designing Tools.........................219

18. Computer Programming in QBASIC ....................................................229

Quiz Section 245-252

Unit 1

Fundamental Knowledge and

Skill of Computer

This unit covers the following chapters.

Chapter 1 Introduction to Computer
Chapter 2 Historical Development of Computer
Chapter 3 Generations of Computer
Chapter 4 Types of Computer
Chapter 5 Introduction to Computer Hardware and Software
Chapter 6 Operating System
Chapter 7 Word Processing Program - 2010
Chapter 8 Spreadsheet Software - 2010
Chapter 9 Presentation Software - 2010

5

Chapter

1 Introduction to Computer

Learning Outcomes

At the end of this lesson, the students will be able to:
tell the definition of computer.
explain the working principle of computer.
list out the advantages and disadvantages of computer.
write the application areas of computer.

Let's Update

. The first electronic computer ENIAC weighed more than 27 tons and took
up 1800 square feet.

. TYPEWRITER is the longest word that you can write using the letters
only on one row of the keyboard.

. Doug Engelbart invented the first computer mouse in around 1964 which
was made of wood.

Introduction

Computer is a machine that performs calculations and process information
with amazing speed and accuracy. A computer is an electronic device that
can perform a variety of operations with a set of instructions. Computer
can access and process data millions of times faster than humans. A
computer can store data and information in its memory, process them
and produce the desired results. Computer is also used as a data processor
device. Input is needed to accomplish a task; a process is carried out on
the input to obtain the output. Every process follows this Input-Process-
Output (IPO) cycle.

6 New Gateway to Computer Science Book- 7

Working principle of computer

INPUT - PROCESS - OUTPUT and STORAGE is the basic working principle
of the computer. Computer receives and processes data according to a
set of instructions given by the user and send to the user as a result. The
results of the processing are usually sent through an output devices.

Input Process Output

Storage

Feedback

Input

Input is any data and instructions entered
into the memory of the computer. It is the act
of entering the data to the computer with the
help of input devices such as keyboard, mouse,
scanner, microphone, light pen, etc.

Processing

The Central Processing Unit (CPU) is
responsible to process the data. When a
computer gets the input with the help of input
devices then it starts to process the data. A
CPU handles all the instructions that it receives
from hardware and software which are available
on the computer. The CPU is also called as
the brain of the computer system.

Introduction to Computer 7

Output

An output unit displays the result after
processing. The main task of output unit is
to display the result. The output is always
meaningful. The output devices can be a
monitor, printer, or speakers. There are two
types of output devices. They are soft copy and
hard copy output.

Storage

The storage devices are capable of holding
information either in permanent or in temporary
form. The storage devices such as hard disk,
pen drive, memory card, etc. are responsible
to store the computer data permanently. A
Random Access Memory (RAM) is a temporary
memory of the computer. The hard disk is the
permanent storage device. Storage devices are
the component of the computer system which are most essential.

Functional units of computer

In order to carry out the operations mentioned in the previous section,
the computer allocates the task between its various functional units. The
central processing unit is divided into three separate units for its operation.

The CPU is the brain of any computer system. It is just like brain that takes
all major decisions, makes all sorts of calculations and directs different parts
of the computer functions by activating and controlling the operations. The
different sections of CPU are discussed below.

Arithmetic Logical Unit (ALU)
Control unit. (CU)
Memory Unit (MU)

8 New Gateway to Computer Science Book- 7

1. Arithmetic Logical Unit (ALU)  

After you enter the data through the input devices, it is stored in the
primary storage unit. The actual processing of the data and instruction
are performed by Arithmetic Logical Unit. The major operations
performed by the ALU are addition, subtraction, multiplication,
division, logic and comparison. Data are transferred to ALU from
storage unit when required. After processing, the output is returned
back to the storage unit for further processing and getting it stored.

2. Control Unit (CU)

The next component of CPU is the
Control Unit, which acts like the
supervisor seeing that whether
the things are done in a proper
manner or not. Control Unit is
responsible for coordinating various
operations using time signal. The
control unit determines the sequence
in which the computer programs and instructions are executed. Things
like processing of programs stored in the main memory, interpretation
of the instructions and issuing of signals for other units of the computer
are done to execute them. It also acts as a switch board operator
when several users access the computer simultaneously. Thereby, it
coordinates the activities of the computer’s peripheral equipment as
they perform the input and output. 

3. Memory Unit (MU)

This is the storage unit of the CPU. All
data and instructions that need to be
processed are stored here before they
are retrieved by the control unit and
sent to the ALU.

Introduction to Computer 9

Quick Learn!

¬¬ A computer is an electronic device that can perform a variety of
operations with a set of instructions.

¬¬ Computer is also used as a data processor device.
¬¬ INPUT-PROCESS –OUTPUT and STORAGE is the basic working

principle of computer.
¬¬ Input is the act of entering the data to the computer with the help

of input devices.
¬¬ A CPU handles all the instructions that it receives from hardware

and software.
¬¬ The main task of output unit is to display the result.
¬¬ The storage devices are capable of holding information

permanently.
¬¬ The computer system is divided into three separate units for

its operation. They are arithmetic logical unit, control unit and
memory unit.
¬¬ The major operations performed by the ALU are addition,
subtraction, multiplication, division, logic and comparison.
¬¬ Control Unit is responsible for coordinating various operations
using time signal.

Characteristics of the computer

The computers are the most useful and powerful devices in different fields
for different purposes. They have the capacity of doing complex tasks.
Nowadays, the uses of the computers are increasing day by day because of
the following characteristics.

Speed:  A computer is a very fast machine which can work at a very high
speed. It takes only few seconds for calculations the data that we take hours

10 New Gateway to Computer Science Book- 7

to complete. The computer can perform millions of instructions within a
few seconds. The speed of the computer is measured in Hertz (HZ).

Accuracy: If the data and instructions given are correct the result given by
the computer will always be accurate. The term GIGO (Garbage in Garbage
Out) applies in this context. If we feed wrong data the computer will also
display the wrong result.

Diligence: A computer is capable of doing the required task again and again
without losing its speed and accuracy. A computer is free from tiredness,
lack of concentration, weakness, etc. It can work for long hours without
creating any errors. It can work for a long time without any rest. If millions
of calculations are to be performed,
a computer will perform every
calculation with the same accuracy.

Versatility: Versatility means
the capacity to perform completely
different type of work. Computers
can be used in different fields for
various purposes. There is a great
role of the computer in every sector
like in education, entertainment,
communication, documentation,
science, engineering, etc.

Storage: Storage means having the capacity to store the data for
the future use. The computer can store a huge amount of data and
information. We can store data in the secondary storage devices such
as hard disk, memory card, CD, DVD, etc. When we save the data in
the secondary storage, then we can get it easily whenever we need.
The computer has also a primary storage devices such as RAM and
ROM.

Introduction to Computer 11

Advantages and disadvantages of the computers

Advantages:

We can work fast and easily with the help of the computer.
It is possible to store a large volume of data.
The output of the computer is always correct if correct input is

given.
A computer can work for a long time.
When user gives commands, it starts to work automatically.

Disadvantages

A computer is useless without electricity.
It may create health problems.
A computer cannot work itself.
It does not have its own decision making capacity.
It may create unemployment problem.
A trained person is required to handle the computer.

Application areas of computer

The computer is an essential part of human life. It is almost impossible
to work without the computer system and technology. Computers play a
vital role in every field. Most countries are being developed rapidly due to
the computerization. Computerization has been done in business, banking,
electronic publishing, engineering, creative designing, fashion designing,
etc. It is used in railways, airlines, defence service, research establishments,
etc. Some of the popular application areas of the computer are discussed
below.

Computer in Education

A teacher can make his/her teaching
techniques interesting and interactive with
the help of the computer tools. Nowadays,
the computers are commonly used in schools

12 New Gateway to Computer Science Book- 7

and colleges for teaching and learning activities. Students can also use the
computer as their learning tools. Students can search about various topics
on the internet and teacher also can take help of the internet and do lots of
research work, so that they can collect lots of ideas and information about
the learning process. A teacher can prepare a slide and demonstrate it in
the class. Students also can do research work in their various subjects that
they want.

Computer in Bank

The banking and financial sectors are using
the computer technology to provide fast
services to the customers. Banks are using
the computer massively these days. With
the help of the computer they can keep the
records of customers, check the balance,
verify the signature, deposit and withdraw
money, etc. Online banking, mobile banking, ATM (Automated Teller
Machine) card, Electronic Fund Transfer system, etc. are also done
because of the use of the computer at bank.

Computer for entertainment

Computers now have almost unlimited access
to any music in the world. Many website
services allow the users to purchase individual
tracks or albums directly from the computer.
Computers also allow musicians to create
artificial instruments to record with MIDI
instruments. Some websites also offer free streaming of television show
and live broadcasting with the help of the internet. In some cases, users
may not even need to pay for the cable service or television because of
online video content.

Computer at hospital

Doctors can get a help from the computer and other
technological devices which are implemented to

Introduction to Computer 13

make the patient feel more secure, more safe, and easier. Hospitals are
using the computer to keep the records of patients, doctors and staff. They
use the computer to keep and display the duty rosters of doctors also. The
computers are used to check the various internal organs of human, so that it
is easy to find out the health problems. X-Ray , CT-Scan, test of heart, test
of kidney, endoscopy, ultrasound, etc. are possible to do within a minute
with the help of the computer. So there is a great role of the computer in
medical science sector as well.

Computer in scientific research

The computers have changed the ways in
which scientific research is compiled and
analysed. Scientists, engineers and researchers
are able to collect various data to work with
research project. The importance of the
computer in scientific research is very high
and the use of the computer can help scientific
research immensely. It is almost invaluable
and priceless tool. 

Computer in business

Almost every business organizations use the computer to complete their
daily tasks. Making contact with clients and
inputting data for reports are easy because
of the computer system. Computers allow to
promote businesses in a more efficient way to
manage affairs in comparison to traditional
paper and folders. Businesses use a variety of
different types of computers such as desktops,
laptops, smartphones and even tablets,
depending on their needs. With computers, employees are able to work
anytime, anywhere.

14 New Gateway to Computer Science Book- 7

Computer in communication

Communication is a way to convey a message,
an idea, a picture, or speech that is received
and understood clearly and correctly by the
person for whom it is sent. The World Wide
Web, Internet and email are massively used to
exchange data these days. Social networking
sites like Facebook, Twitter, Viber and
LinkedIn are being used these days to exchange
information very easily. Social networking provides us with a constant
stream of updates and information than that of sending individual notes.

Quick Learn!

¬¬ We can work fast and easily with the help of the computer.

¬¬ When a user gives commands, the computer starts to work
automatically.

¬¬ A computer is useless without electricity.

¬¬ A trained person is required to handle the computer system
properly.

¬¬ Nowadays, the computers are commonly used in school and
college for teaching and learning activities.

¬¬ With the help of the computer at bank, we can keep the records
of customers, check the balance, verify the signature, deposit and
withdraw money, etc.

¬¬ Hospitals are using the computers to keep the records of patients,
doctors and staff.

¬¬ At hospital the computer can be used for X-Ray, CT-Scan, test of
heart, test of kidney, endoscopy, ultrasound, etc.

¬¬ Social networking sites like Facebook, Twitter, Viber and LinkedIn
are being used these days to exchange the information very easily.

Introduction to Computer 15

1. Choose the best answer from the given alternatives.

a. The act of entering data to the computer is called:

i. Input ii. Process iii. Output

b. Which of the following is a temporary memory?

i. ROM ii. RAM iii. Hard disk

c. Which of the following is the functional unit of the computer?

i. Control Unit ii. Arithmetic Logic Unit iii. Both

d. Which of the following is called the brain of the computer?

i. RAM ii. Hard Disk iii. CPU

e. Which of the following is the application areas of a computer?

i. Business ii. Science & Technology

iii. Both (i) and (ii)

f. For what purpose are computers used at bank?

i. To keep the record of doctors.

ii. To verify the signatures

iii. To work with animations.

g. Which of the following is possible to do with the computer
technology at hospital?

i. X-Ray and CT Scan

ii. Test of heart iii. Both

h. Which of the following is related to social media?

i. Twitter ii. Ms-Word iii. PowerPoint

2. State whether the given statements are true or false.

a. Input is the act of entering the data to the computer.

b. A CPU handles all the instructions that it receives from hardware
and software which are available on the computer.

c. A ROM handles all the instructions that it receives from hardware
and software.

d. The main task of input unit is to display the result.

16 New Gateway to Computer Science Book- 7

e. We can work fast and easily with the help of the computer.
f. Nowadays, the computers are commonly used in school and

college for teaching and learning activities.
g. We can keep the records of customers, check the balance, verify

the signature, deposit and withdraw money, etc. at bank with the
help of computer.

3. Write down the single technical term for the following.

a. A computer unit that is used for the actual processing of data and
instruction.

b. The unit which is responsible for coordinating various operations
using time signal.

c. It is the brain of any computer system.
d. It is a way to convey a message, an idea, a picture, or speech that

is received and understood clearly and correctly by the person for
whom it is sent.
e. A storage device that is capable for holding information
permanently.

4. Fill in the gaps with correct word(s).

a. Input is the act of entering the data to the computer with the help
of ...................... devices.

b. A ...................... handles all the instructions that it receives
from hardware and software which are available on the computer.

c. The ...................... is the basic storage component of the computer
system which is most essential to operate the computer.

d. The computer system is divided into three separate units for its
operation. They are Arithmetic Logical Unit, ...................... and
Central Processing Unit.

e. With the help of computers, we can keep the records of customers,
check the balance verify the signature at......................

f. ...................... are used to check the various internal organs of
human.

g. Facebook, Twitter, Viber and LinkedIn are popular ......................
web sites.

Introduction to Computer 17

5. Write full form of the following:

a. GIGO b. ATM c. CPU

d. ALU e. CU. f. IPO

g. RAM h. ALU

6. Answer the following questions.

a. Define the computer with its working principle.

b. What are the functional units of the computer?

c. Mention any four advantages and disadvantages of the computer.

d. Write any six application areas of the computer.

e. List out the different character of the computer.

f. What is the role of the computer in communication?

g. Why are the computers popular at banking sector?

h. Name any three social networking web sites.

i. Why is the computer called a versatile machine?

j. Define the following terms:

i. Input ii. Processing

iii. Output iv. Storage

Project work and Activity

a. Divide students in various group and conduct a presentation on the
following topics.

¬¬ Working principle of the computer.

¬¬ Application areas of the computer.

b. Conduct a speech competition about the “Role of the computer for
the development of a country.”

18 New Gateway to Computer Science Book- 7

Chapter Historical Development of
Computer
2

Learning Outcomes

At the end of this lesson, the students will be able to:
tell about the mechanical, electro-mechanical and electronic calculating

devices.
write the history of computer in Nepal.

Let's Update

. There are more than 5000 new computer viruses released every month.
. If there was a computer as powerful as the human brain, it would be able

to do 38 thousand trillion operations per second and hold more than 3580
terabytes of memory.
. An average person normally blinks 20 times a minute, but when using a
computer he/she blinks only 7 times a minute.

Introduction

The development of modern computer has a very long historical background.
The history of the computer started from the Stone Age. People use the
stones and other objects for the counting. The history of computer would
use from the history of number system and it was used for counting. The
hindu philosophers were the developer of the computer number system.
Many inventors worked a lot for the development of different calculating
devices. According to the technology and concept used on devices, there are
three types of calculating devices such as manual calculating device, electro
mechanical and electronic devices.

Historical Development of Computer 19

Mechanical Calculating Devices

Abacus

Abacus was the first manual calculating device
developed by the Chinese people before 3000
BC. The abacus was made from the wooden
frame with beads sliding on wires. It has two
parts. They are called heaven and earth which is
separated by the mid bar. Each bead of heaven
has the value 5 and each bead of earth has the value 1. The first abacus was
most likely based on a flat stone covered with sand or dust.

Napier’s Bone

A Scottish mathematician and politician John
Napier developed a machine called Napier’s
Bone in 1617 AD. In 1614 AD he developed the
concept of logarithm. Napier also gave the idea
of the decimal fraction by starting the use of
decimal points. Napier Bones was also used as
a calculator. It was used for the calculations of
product and quotients of numbers.

Slide Rule

The slide rule has two sets of scales joined
together with a marginal space between the
scales. Slide rule was the invention of William
Oughtred which was introduced in 1620 AD.
The slide rule was based on logarithm. It was
a mechanical analog device that was used for
making numerical computations and reading
such as multiplication, division, powers, roots,
functions, etc.

20 New Gateway to Computer Science Book- 7

Pascaline

A French mathematician Blaise Pascal
developed this device in 1642 AD at the age
of 19. He developed this device to support his
father who worked as a tax commissioner. This
device was able to add and subtract only. It was
capable to do the calculations upto eight digits
only. Pascal’s machine consisted a series of gears
with 10 teeth each, representing the numbers 0
to 9. As each gear made one turn it would trip
the next gear up to make 1/10 of a revolution. The Pascal programming
language was named in his honour. 

Stepped Reckoner

Gottfried Wilhelm von Leibniz invented a
calculating machine known as Leibniz’s
Wheel or the Step Reckoner in 1673 AD. It could
add and subtract, like Pascal’s machine, but it
could also multiply and divide. This device was
also called as Leibniz calculating device. It was
used in many calculating machine till 1970 AD.

Jacquard’s Loom

Joseph Marie Jacquard, a silk weaver, invented
this machine in 1804 AD. This loom was the first
to use punched card with punched holes. The
punched cards control the actions of the loom,
allowing automatic production of intricate
woven patterns.

Charles Babbage's Engine

Babbage is known as the Father of the modern
computer. He was the first person to develop
the concept of modern digital computer which
works on the principle of Input-process-output
and storage. Babbage was born on December
26, 1791 AD at London and died on October
18, 1871 AD. He was a popular mathematician,
philosopher, inventor and mechanical engineer.

Historical Development of Computer 21

The inventions of Babbage are given below.
i. Difference engine

It was the first invention of Babbage
introduced in 1822 AD. It was big in size. It
was powered by the steam. Later on it was
developed for commercial purpose also. It
was an automatic mechanical calculator
designed to tabulate polynomial functions.

ii. Analytical engine

It was the second invention of Babbage
which was introduced in 1833 AD. The
analytical engine was general purpose
mechanical computer. This device
contained the store, mill, input and output
section.

Quick Learn!

¬¬ Abacus was the first manual calculating device developed by the
Chinese people before 3000 BC.

¬¬ The abacus has two parts they are called heaven and earth which
was separated by the mid bar.

¬¬ A Scottish mathematician and politician John Napier developed a
machine called Napier’s Bone in 1617 AD.

¬¬ In 1614 AD John Napier developed the concept of logarithm
¬¬ The slide rule has two sets of scales joined together with a marginal

space between the scales.
¬¬ The slide rule was the invention of William Oughtred which was

introduced in 1620 AD.
¬¬ A French mathematician Blaise Pascal developed Pascaline in

1642 AD.
¬¬ Pascaline was capable to do the calculations upto eight digits only.
¬¬ Gottfried Wilhelm von Leibniz invented a calculating machine

known as Leibniz’s Wheel in 1673 AD.
¬¬ Babbage is known as the father of the modern computer .
¬¬ Analytical engine and difference engine were the inventions of

Babbage.

22 New Gateway to Computer Science Book- 7

Tabulating Machine

In 1887, Dr. Herman Hollerith developed this
machine. The tabulating machine was designed
to assist in summarizing information stored
on punched cards. It was used to process data
for the 1890 of U.S. Census. Hollerith invented
the punch card technology. In 1896 AD Hollerith
founded the Tabulating Machine Company
which is popularly known as International
Business Machine Company these days.

Lady Augusta Ada Lovelace

Lady Augusta Ada Lovelace was a daughter
of Lord Byron. She was born in December
1815 AD and died in November 1852 when
she was of just 36 years. She was the first to
recognise that the machine had applications
beyond pure calculation, and created the
first  algorithm  proposed to be carried out by
such a machine. As a result, she is often regarded
as the first to recognise the full potential of a "computing machine" and the
first computer programmer.

Electro-Mechanical Calculating devices

Mark I

It was the first electromechanical calculating
device developed by Howard Hathaway Aiken
who was born in 1901 AD. He was a professor
of Harvard University of the USA. This device is
also called as Howard Mark I. It was built by IBM
in 1937 AD. It was also called ASCC (Automatic
Sequence Controller Calculator). It was huge with about 5 tons weight, 51
feet long, 8 feet height and 2 feet in depth.

Historical Development of Computer 23

ABC ( Atanasoff Berry Computer)

The Atanasoff-Berry Computer was the
electromechanical digital computer built in
1942 AD at Iowa State University by John
Vincent Atanasoff and Clifford Berry. This
computer is regarded as the first digital
computer. It has electronic switching elements
and could perform binary arithmetic.

Quick Learn!

¬¬ Lady Augusta Ada Lovelace was a daughter of Lord Byron.
¬¬ Lady Ada is called the first computer programmer.
¬¬ In 1887, Dr. Herman Hollerith developed Mark I.
¬¬ Hollerith invented the punch card technology. T
¬¬ Mark I was the first electromechanical calculating device devel-

oped by Howard Hathaway Aiken.
¬¬ The Atanasoff-Berry Computer (ABC) was the electromechanical

digital computer built in 1942 AD.
¬¬ ABC is regarded as the first digital computer.
¬¬ ABC has electronic switching elements and could perform binary

arithmetic.

Electronic Calculating Devices

ENIAC (Electronic Numerical Integrator and Calculator)

It  was the  first general-purpose electronic
computer built in 1946 at University of
Pennsylvania, USA by John Mauchly and J.
Presper Eckert. It was named as Electronic
Numerical Integrator and Calculator

24 New Gateway to Computer Science Book- 7

(ENIAC). ENIAC contained 17,468 vacuum tubes, 7,200 crystal diodes,
1,500 relays, 70,000 resistors, 10,000 capacitors and around 5 million
hand-soldered joints. Input was possible in this device from an IBM card
reader, and an IBM punch card was used for output. These cards could be
used to produce printed output offline using an IBM accounting machine.

EDSAC (Electronic Delay Storage Automatic Calculator)

EDSAC stands for Electronic Delay Storage
Automatic Computer.  It was developed
by M.V. Wilkes at Cambridge University
in 1949. Two groups of individuals were
working at the same time to develop the first
stored-program computer. It performed
arithmetic and logical operations without
human intervention. The key to the success
was in the stored instructions which it
depended upon only for its operation. This machine marked the beginning
of the computer age.  It used stored program concept for the first time and
also used the binary numbers.

UNIVAC (UNIVersal Automatic Computer)

The UNIVAC was designed principally by
J. Presper Eckert and John Mauchly, the
inventors of the ENIAC. It was the  first
commercial computer invented in the
United States. The machine contained
5,600 tubes, 18,000 crystal diodes, and
300 relays. It utilized a Mercury delay line,
magnetic tape, and typewriter output. The
UNIVAC was used for general purpose
computing with large amounts of input and output. The UNIVAC was also
the first computer equipped with a magnetic tape unit and was the first
computer to use buffer memory.

Historical Development of Computer 25

EDVAC (Electronic Discrete Variable Automatic Computer)

EDVAC stands for Electronic Discrete
Variable Automatic Computer. It was
developed in 1952. The concept of storing
data and instructions inside the computer
was introduced in this device. John William
Mauchly and John Presper Eckert developed
this device. It was the first computer based
on stored program concept. This computer
also worked on binary digits and used stored program concept. It used
6,000 vacuum tubes and 12,000 diodes which consumed 56 kilowatt
power. It was popularly used upto 1961 AD.

Quick Learn!

¬¬ ENIAC was the  first general-purpose electronic computer  built
in 1946 AD.

¬¬ John Mauchly and J. Presper Eckert were the inventors of ENIAC.
¬¬ EDSAC was developed by M.V. Wilkes at Cambridge University in

1949 AD.
¬¬ EDVAC was developed in 1952 AD.
¬¬ John William Mauchly and John Presper Eckert developed EDVAC.
¬¬ EDVAC was the first computer based on stored program concept.
¬¬ EDVAC used 6,000 vacuum tubes and 12,000 diodes which

consumed 56 kilowatt power.

26 New Gateway to Computer Science Book- 7

History of Computer in Nepal

The IBM 1401 model computer which belongs to the second generation
was introduced in Nepal for the first time in 2028 BS. This computer was
brought on rent and after that another second generation mainframe
computer ICL 2950/10 model was introduced in Nepal. To work with
the technology, Yantrik Sarinikaran Kendra (Electronic Data Processing
Center) was established which was later called as National Computer Centre
(NCC). After 2039 B.S. microcomputer like; Apple , Vector, Sirus, etc. were
introduced in Nepal. After the year of 2039 BS, computers have been used
in different government sectors like banking, agriculture, universities,
etc. Now, there are thousands of computer in states providing computer
education, assembling, maintenance, etc. across Nepal. Now a days, the
latest technologies and devices are available in our country.

1. Choose the best answer from the given alternatives.

a. Which of the following was the first manual calculating devices?

i. RAM ii. ABACUS iii. Slide Rule

b. When was slide rule developed?

i. 1642 AD ii. 1620 AD iii. 1720 AD

c. What was the second invention of Babbage?

i. Difference Engine

ii. Analytical Engine iii. IBM

d. Who was the founder of tabulating machine company?

i. Babbage ii. Hollerith iii. Pascal

e. Who was the father of Lady Ada?

i. Babbage ii. Pascal iii. Lord Byron

f. Which was the first commercial computer?

i. ENIAC ii. EDSAC iii. UNIVAC

Historical Development of Computer 27

2. State whether the given statements are true or false.

a. Abacus was the first manual calculating device.
b. In 1619 AD, John Napier developed the concept of logarithm.
c. Hollerith invented the punch card technology.
d. ABC is also named as the first digital computer.
e. EDSAC was developed by M.V. Wilkes at Cambridge University

in 2004 AD.
f. John Mauchly and J. Presper Eckert are the inventors of Analytical

engine.
g. EDVAC used 6,000 vacuum tubes and 12,000 diodes which

consumed 56 kilowatt power.
h. A Scottish mathematician and politician John Napier developed

a machine called Napier’s Bone in 1617 AD.

3. Write down a single technical term for the followings.

a. It was the first general purpose electronic computer built in 1946
AD.

b. The first model of computer that was brought for the first time in
Nepal.

c. The first manual calculating device developed by Chinese.
d. The first invention of Babbage which was introduced in 1822 AD.
e. The first general purpose electronic computer built in 1946 AD.

4. Fill in the gaps with correct word(s).

a. Abacus has two parts. They are called ………….. and earth.
b. A Scottish mathematician and politician John Napier developed

a machine called Napier’s Bone in ……… AD.
c. A French mathematician …… developed Pascaline in 1642 AD.
d. Babbage is known as the ………………….. of the modern computer.
e. Analytical engine and ………………………. engines were the

inventions of Babbage.
f. In 1887, Dr. ………………… Hollerith developed Mark I.
g. The Atanasoff -Berry Computer (ABC) was the ………………………….

digital computer built in 1942 AD.
h. ENIAC was the  first general-purpose electronic computer  built

in ……………….. AD.

28 New Gateway to Computer Science Book- 7

5. Write down the full forms of the following abbreviations:

EDSAC , UNIVAC , EDVAC, EDSAC, IBM, ABC, NCC

6. Answer the following questions.

a. What was the first manual calculating device? When was it
invented?

b. Write a few lines about Jacquard’s loom.
c. For what purpose was tabulating machine developed?
d. Which computer is called the first digital computer?
e. Explain ENIAC.
f. Who were the inventors of UNIVAC computer?
g. Which was the first computer that was based on stored program

concept?
h. Make a list of any six computers used in the history of the

computer.

Project work and Activity

a. Divide students in various groups and conduct a presentation on
the following topic.
¬¬ Historical Development of Computer

b. Prepare a chart as given below and paste it to decorate your class
room. Also paste one at your school’s notice board.

S.N. Name of Device Name of Inventor Date of Invention
1.
2.
3.
4.
5.
6.
7.
8.
9.
10.

Historical Development of Computer 29

Chapter

3 Generations of Computer

Learning Outcomes

At the end of this lesson, the students will be able to:
explain different types of computer generations, and their memory unit.
tell the features of each generation of computer.
write the name of computers used in different computer generations.

Let's Update

. The house where Bill Gates lives, was designed using a Macintosh computer.
. The first ever hard disk drive was made in 1979, and could hold only 5MB

of data.
. A group of 12 engineers designed IBM PC and they were called “The Dirty

Dozen”.

Generation First Generation
of Second Generation

Computer Third Generation
Fourth Generation
30 New Gateway to Computer Science Book- 7
Fifth Generation

Introduction

Computer Generation is the process of changing the technology that the
computers used. Initially, the generation term was used to distinguish
between varying hardware technologies. Nowadays, generation includes
both hardware and software, which together makes up an entire computer
system. There are five computer generations till date based on the period
of development and the features combined. Each generation has been
discussed in detail along with their time period, memory component and
features in the sections prearranged underneath.

Generation of Computer

The generations of computers are explained below.

First Generation

The first generation computers were used

during 1946-1958. Vacuum tubes were the

memory component of these generations

of computer. It was developed by Lee De

Forest. Vacuum tubes were like electric

bulbs which produced a lot of heat. IBM 650

They were very expensive and only large

organizations were able to afford it. Punch cards, paper tape, and magnetic

tape were used as input and output devices. The computers in this generation

used machine code as the programming language.

The name of the first generation computers are:

ENIAC (Electronic Numerical Integrator And Calculator)
EDSAC (Electronic Delay Storage Automatic Calculator)
EDVAC (Electronic Discrete Variable Automatic Computer)
UNIVAC (Universal Automatic Computer)

Generations of Computer 31

Feature of the first generation computers

They used valves or vacuum tubes as their main electronic component.
They were large in size, slow in processing and had less storage

capacity.
They consumed lots of electricity and produced lots of heat.
Their computing capabilities were limited.
They were not so accurate and reliable.
They used machine level language for programming.
They were very expensive.

Second Generation

The second generation computers were used

during 1959-1964. The memory component

was transistor of this generation. John

Bardeen and Walter Brattain were the

inventors of transistors. These computers

were cheap, consumed less power, were more

compact in size, were more reliable and faster UNIVAC II
than the first generation. In this generation,

magnetic cores were used as the primary memory and magnetic tape and

magnetic disks as secondary storage devices. Assembly language and high

level programming language were used during this generation.

The names of the second generation computers are:

IBM 1620, IBM 1401, IBM 7094

CDC 1604, CDC 3600

UNIVAC 1108

Feature of second generation computers

Transistors were the main memory components.
They have more reliable than previous generation computers.
The size was smaller than the first one.
It generates less heat as compared to previous generation.
It consumed less electricity as compared to previous generation.
It was faster than the first generation computers.
The processing speed was measured in microsecond.

32 New Gateway to Computer Science Book- 7

Quick Learn!

¬¬ Computer Generation is the process of changing the technology
that the computers used.

¬¬ There are total five computer generations till date.

¬¬ The first generation computers were used during 1946-1958.

¬¬ Vacuum tubes were the memory components of the first generations
computer.

¬¬ Vacuum tubes were like electric bulbs which produced a lot of heat.

¬¬ The second generation computers were used during 1959-1964
AD.

¬¬ The memory component of the second generation was transistor.

¬¬ John Bardeen and Walter Brattain were the inventors of
transistors.

¬¬ In the second generation, magnetic cores were used as the primary
memory.

Third Generation

The third generation computers were used

during 1964-1970. The memory component was

Integrated Circuit (IC). A single IC had many

transistors, resistors and capacitors along with

the associated circuitry. It was invented by Jack

Kilby and Robert Noyce. This development made

computers smaller in size, reliable and efficient IBM 370
in function. Remote processing, Time-sharing,

Real-time and Multi-programming operating system were used during this

generation. High level language like FORTRAN, COBOL , etc. was used

during this generation.

Generations of Computer 33

The name of the third generation computers are:

IBM-360 series
Honeywell-6000 series
PDP(Personal Data Processor)
IBM-370/168
TDC-316 computers were used during third generation.

Features of the third generation computers

They used Integrated Circuit (IC) chips in place of the transistors.
Semiconductor memory devices were used.
The size was greatly reduced, the speed of processing was high, they

were   more accurate and reliable.
Large Scale Integration (LSI) and Very Large Scale Integration (VLSI)

were also developed.
The mini computers were introduced in this generation.
They used high level language for programming.

Fourth Generation

The fourth generation computers are being used
from 1971 to till date. Microprocessors are the
main memory components of this generations
of computer which are also called VLSI. The
microprocessor is made with the help of Large Scale
Integration (LSI) and Very Large Scale Integrated
(VLSI) circuits. The fourth generation computers Apple/ Machintosh
are more powerful, compact, reliable, and affordable. As a result, it gave rise
to personal computer (PC) revolution. All the Higher level languages like C,
C++, JAVA, Visual Basic, PHP, etc. are used in this generation. Windows,
UNIX, Linux, Mac OS, etc. are the popular operating system used by this
generation.

34 New Gateway to Computer Science Book- 7

The name of the fourth generation computers are:
DEC 10, STAR 1000, PDP 11
CRAY-1(Super Computer), CRAY-X-MP(Super Computer),
IBM PC, Apple Macintosh
Features of the fourth generation computers
It uses VLSI technology to produce a single microprocessor.
It is very cheap and portable than previous generations.
It is very accurate and versatile.
The working speed is up to picosecond and femtosecond.
It has very advanced type of input and output unit such as scanner,

light pen, touch screen, etc.

Fifth Generation

The development of the fifth generation started
from 1990 which is still incomplete. The
fifth generation computers are mainly future
computers. Some modern computers belong
to this generation. The aim of these computers
is to develop devices that respond to natural
language input and are capable of learning
and self-organization. In these computers
massive numbers of CPUs are used for more
efficient performance. Voice recognition is a special feature in these
computers. This generation is based on parallel processing hardware and
AI (Artificial Intelligence) software. AI is an emerging branch in computer
science, which interprets means and method of making computers think
like human beings. We can imagine that this computer will be able to
use natural languages like English, Germany, French and even Nepali for
processing.

Features of the fifth generation computers

The concept of Artificial Intelligence (AI) will be used.

It will be able to understand various natural languages.

It will be able to think and decide.

The operating speed will be faster than the fourth generation
computers.

It will create the advancement in Parallel Processing.

Generations of Computer 35

Quick Learn!

¬¬ The third generation computers were used during 1964-1970 AD.
¬¬ The memory component of the third generation was Integrated Circuit

(IC).
¬¬ IC was invented by Jack Kilby and Robert Noyce.
¬¬ The fourth generation computers are being used from 1971 AD.to till

date.
¬¬ Microprocessor are the main memory component of the fourth

generation computer.
¬¬ The microprocessor was made with the help of Large Scale

Integration (LSI) and Very Large Scale Integrated (VLSI) circuits.
¬¬ The fifth generation is based on parallel processing hardware and

AI (Artificial Intelligence) software.
¬¬ AI is an emerging branch in the computer science, which interprets

means and method of making the computers think like human
beings.

1. Choose the best answer from the given alternatives.

a. Which of the following belongs to the first generation of computer?

i. IC ii. ABACUS iii. Vacuum Tube

b. In which generation were punch cards and magnetic tape used

as input and output devices?

i. First ii. Second iii. Third

c. Which generations of computers were used during 1959-1964?

i. First ii. Second iii. Third

d. In which generation, does ‘CDC 1604’ computer belong?

i. Second ii. Third iii. Fourth

e. Which of the following computer belongs to the third generation

computer?

i. IBM-370/168 ii. ICL 2900 iii. CDC 1604

36 New Gateway to Computer Science Book- 7

2. State whether the following statements are true or false.

a. There are total six computer generations.
b. The first generation computers were used during 1946-1958.
c. Vacuum tubes were like electric bulbs which produced a lot of

heat.
d. The third generation computers were used during 1959-1964 AD.
e. John Bardeen and Walter Brattain were the inventors of Vacuum

Tube.
f. The memory component of the third generation computer was

Integrated Circuit (IC).
g. The development of the fifth generation computer started from

1990 which is still incomplete.
h. The second generation computers were based on parallel

processing hardware and AI (Artificial Intelligence) software.
3. Write down the single technical term for the following:

a. The memory component used by the first generation computer.
b. The memory component used by the second generation computer.
c. The generation of computer which was used during 1964 to 1970

AD.
d. It is made with the help of LSI and VLSI.
e. It is an emerging branch in computer science, which interprets

means and method of making computers think like human
beings.
4. Fill in the gaps with correct word(s).

a. ………………… were the memory component of the first generation
of computer.

b. The memory component of the …………… generation was
transistor.

c. The third generation computers were used during 1964 to………….
AD.

d. Microprocessors are the main memory components of the
…………. generation computer.

e. Integrated circuit was invented by …………… and Robert Noyce.
f. The memory component of the…………… generation was

Integrated Circuit (IC).

Generations of Computer 37

5. Match the following devices with their generations.

Vacuum Tube Second generation

Transistor Third generation

Integrated Circuit Fourth generation

Microprocessor First generation

6. Answer the following questions.

a. What is a computer generation? What are the types of the
computer generations?

b. Write down the memory components of each generation
computer.

c. Mention any four features of the first generation computer.
d. Write down the name of the second generation computers.
e. Write any three special features of the fourth and the fifth

generation computer.
f. Name the devices that were used during the third and the fourth

generation computer.
g. Explain about the first generation computer.

Project work and activity

a. Divide students in various groups and conduct a presentation on
the topic.

¬¬ The generations of computer.

b. Complete the given chart and demonstrate it in the class.

Name of Memory Used One special
Component date feature
Generation
First
Second
Third
Fourth
Fifth

38 New Gateway to Computer Science Book- 7

Chapter Types of Computer

4

Learning Outcomes

At the end of this lesson, the students will be able to:
tell the different types of computer.
define analog, digital and hybrid computer.
identify the personal computer, super computer, mainframe computer,

minicomputer, etc.
explain the types of digital computer.

Let's Update

. The original name of windows was Interface Manager.
. The first microprocessor created by Intel was the 4004. It was designed for

a calculator.
. IBM 5120 from 1980 was the heaviest desktop computer ever made.

Introduction

People are using different types of computers according to their
requirement. Computers are classified on the basis of their work, size,
brand and model. The computers that you are using at your home and the
computers that are being used for film animation are different. The types
of computers are classified according to the purpose of uses such as special
purpose and general purpose. Here we are going to discuss some common
types of computer.

Types of Computer 39

Analog Computer

The computers which provide us with
continuous information are called
analog computer. They represent
physical quantities in the form of
waves or in continuous form. Analog
computers are used to process analog
data. Analog data is continuous in
nature and which is not discrete or
separate. Such type of data includes
temperature, pressure, speed, weight,
voltage, depth, etc. Analog computers
are the first developed computers which
provided the basis for the development of the modern digital computers.
The Speedometer of a car measures speed, the change of temperature is
measured by a thermometer, the weight is measured by weight machine.
The speedometer, thermometer, weight machine, etc. are the examples of
analog devices.

Digital Computer

A digital computer works with digits
to represent numerals, letters or other
special symbols. A digital computer can
be used to process numeric as well as
non-numeric data. The computers which
present physical quantities with the help
of symbols or numbers and provide us
with discrete information are called
digital computers.
Digital Computers operate on inputs
which are ON-OFF type and its output is
also in the form of ON-OFF signal. Normally, an ON is represented by a '1'
and an OFF is represented by a '0'. So we can say that digital computers
process information which is based on the presence of an electrical charge.
Most of the computers available today are digital computers.

40 New Gateway to Computer Science Book- 7

Hybrid Computer

A hybrid computer is a combination
of analog and digital computers. It
combines the best features of both types of
computers. It has the speed of analog
computer and the memory and accuracy
of digital computer. Hybrid computers are
used mainly in specialized applications.
Hybrid computer processes both
continuous and discrete data.
For  example  a petrol pump contains a processor that converts fuel flow
measurements into quantity and price values. In hospital Intensive Care
Unit (ICU), an analog device is used which measures blood pressure and
temperature. which is then converted and displayed in the form of digits.

Quick Learn!

¬¬ The computers which provide us with continuous information are
called analog computer.

¬¬ Analog computers are used to process analog data.
¬¬ Analog data is continuous in nature and which is not discrete or

separate.
¬¬ A digital computer works with digits to represent numerals, letters

or other special symbols.
¬¬ A digital computer can be used to process numeric as well as non-

numeric data.
¬¬ A hybrid is a combination of analog and digital computers. It has

the best features of both analog and digital computers.
¬¬ Hybrid computer processes both continuous and discrete data.

Types of Computer 41

Personal Computer

Personal computers are small, comparatively
inexpensive computers designed for personal
use. Personal computers are based on the
microprocessor technology that enables to put
an entire CPU on one chip. Personal computers
are used for word processing, accounting,
desktop publishing, and database management
applications. Personal computers are designed as single-user systems,
these systems are normally linked together to form a network.

Super Computer

Supercomputers are the fastest computers
developed so far. Supercomputers are very
expensive and are being using for specialized
applications that require huge amount of
mathematical calculations. For example, weather
forecasting, scientific simulations, (animated)
graphics, fluid dynamic calculations, nuclear energy research, electronic
design, and analysis of geological data .

Mainframe Computer

Mainframe computer is very large in size and is an
expensive computer capable of supporting hundreds
or even thousands of users simultaneously.
Mainframe computer executes many programs

42 New Gateway to Computer Science Book- 7

concurrently and supports many simultaneous executions of programs.
Mainframe computers are not a powerful as supercomputers, but they
are quite expensive. Many large firms and government organizations
use Mainframe computers to run their business operations. Hundreds of
user can work together with this computer system at a time. Mainframe
computers are the fastest computers with large data storage capacity,
Mainframe computers can also process and store a large amount of data.

Mini Computer

It is a midsize multi-processing system capable of supporting up to 250
users simultaneously. A minicomputer is a type of computer that possesses
most of the features and capabilities of a large computer but is smaller in
physical size. Minicomputers are used by small
businesses and firms. Minicomputers are also
called as “Midrange Computers”. These computers
are not designed for a single user. Individual
departments of a large company or organizations
use Minicomputers for specific purposes.

Workstation Computer

Workstation is a computer used for engineering
applications like CAD (Computer Aided Design)
and CAM (Computer Aided Manufacture),
desktop publishing, software development,
and other types of applications. Workstations
generally come with a large, high-resolution
graphics screen, a large amount of RAM, inbuilt
network support, and a graphical user interface.
Most workstation computers have mass storage device such as a disk drive.

Types of Computer 43

Quick Learn!

¬¬ Personal computers are small, comparatively inexpensive
computer designed for an individual user.

¬¬ Personal computers are used for word processing, accounting,
desktop publishing, and database management applications.

¬¬ Personal computers are designed as single-user systems.
¬¬ Supercomputers are the fastest computers developed so far.
¬¬ Supercomputers are very expensive and are used for specialized

applications.
¬¬ Mainframe computer is very large in size and is an expensive

computer capable of supporting hundreds or even thousands of
users simultaneously.
¬¬ The mainframe computers are the fastest computers with large
data storage capacity.
¬¬ Minicomputers are used by small businesses & firms.
¬¬ Workstation computers are mostly used for engineering
applications like CAD, CAM , etc.

Types of Digital Computer

Microcomputer

A microcomputer is a computer with
a central processing unit (CPU) as a
microprocessor designed for individual
use; a microcomputer is smaller than a
mainframe and a minicomputer. Desktop,
laptops, personal digital assistant (PDA),
tablets and smartphones are the examples
of microcomputer. The microcomputers
are widely used as the fastest growing
computers. These computers are the

44 New Gateway to Computer Science Book- 7

cheapest among the other three types of computers. The Micro-computers
are specially designed for general proposes like entertainment, education
and personal work. Dell, Apple, Samsung, Sony and Toshiba. companies
are producing various microcomputers these days.

Laptop / Notebook Computer

Laptop computer is a portable
personal computer powered by a battery
or an AC cord plugged into an electrical
outlet. Laptop computers are another
category of personal computers. These
computers are small in size and light
packed in. These computers are moveable
because they work on batteries and
can operate without an external power
source. Laptop computers are also called
Notebook computers. DEL, HP, ACER, SAMSUNG, TOSHIBA, etc. are the
popular laptop manufacturing companies.

Quick Learn!

¬¬ A microcomputer is a computer with a central processing unit
(CPU) as a microprocessor designed for individual use.

¬¬ A microcomputer is smaller than a mainframe and a minicomputer.
¬¬ Desktop, laptops, personal digital assistant (PDA), tablets and

smartphones are the examples of microcomputer.
¬¬ The microcomputers are widely used as the fastest growing

computers.
¬¬ Microcomputers are the cheapest computers among the other

types of computers.
¬¬ The Microcomputers are specially designed for general proposes.
¬¬ Laptop computer is a portable personal computer powered by a

battery or an AC cord plugged into an electrical outlet.
¬¬ DEL, HP, ACER, Samsung, etc. are the popular laptop

manufacturing companies.

Types of Computer 45

1. Choose the best answer from the given alternatives.

a. Speedometer is an example of ……………computer

i. analog ii. digital ii. hybrid

b. Which of the given computer operates data in ON-OFF method?

i. Analog ii. Digital iii. Hybrid

c. Which of the following computer has the quality of both analog

and digital computer?

i. Hybrid ii. Supercomputer iii. Microcomputer

d. Which of the following computer is a type of computer that
possesses most of the features and capabilities of a large computer
but is smaller in physical size.

i. Hybrid ii. Supercomputer iii. Digital computer

e. Which of the following computer is called Notebook computers.

i. Laptop ii. Super computer iii. Minicomputer

f. Which computer are called as “Midrange Computers”.

i. Minicomputer ii. Supercomputer iii. Microcomputer

2. State whether the given statements are true or false.

a. Analog computers are used to process digital data.

b. Analog data is discontinuous nature and which is not discrete or
separate.

c. A digital computer can be used to process numeric as well as non-
numeric data.

d. A hybrid computer is a combination of analog and digital
computers.

e. Personal computers are designed as multi-user systems.

46 New Gateway to Computer Science Book- 7

f. A microcomputer is smaller than a mainframe and a
minicomputer.

g. Microcomputers are the cheapest among the other types of
computers.

h. Desktop computers are very small in size as laptop computers.

3. Write down the single technical term for the followings.
a. A computer that works with digits to represent numbers, letters
or other special symbols.
b. A device used to measure the speed of vehicles like car, motorbike
etc.
c. A computer which has the quality of both analog and digital
computer.
d. These types of computers are small, comparatively inexpensive
and specially designed for personal use.
e. A portable computer powered by a battery or an AC cord plugged
into an electrical outlet.

4. Fill in the gaps with correct word(s).

a. ……………… are used by small businesses & firms.
b. A …………………… is a computer with a central processing unit

(CPU) as a microprocessor designed for individual use.
c. Desktop, laptops, personal digital assistant (PDA), tablets and

smartphones are the examples of ……………………..
d. The Microcomputers are specially designed for …………………

proposes .
e. …………………. are also called as “Midrange Computers”.
f. A ……………………… is a combination of analog and digital

computers.
g. A ………………… computer can be used to process numeric as well

as non-numeric data.
h. Analog data is continuous nature and which is not

…………………….…
i. ……………………… computer processes both continuous and

discrete data.

Types of Computer 47

5. Write full form for the following abbreviations:

a. PC b. CAM c. CAD d. PDA

6. Match the following types of the computers with their
continuations.

Analog Computer combination of analog and digital computer

Digital Computer designed for single user

Hybrid Computer speedometer

Personal Computer works with digits

7. Answer the following questions.

a. What is analog and digital computer?
b. What type of computers are hybrid computers?
c. What is supercomputer?
d. What is the use of workstation computer?
e. Which computer is called midrange computer?
f. Write any three points about personal computer.

Project work and activity

a. Collect the figure of analog, digital , hybrid, super and mainframe computer
and paste them in a chart paper.

b. Conduct a presentation program about personal computer.

48 New Gateway to Computer Science Book- 7

Chapter Introduction to Computer
Hardware and software
5

Learning Outcomes

At the end of this lesson, the students will be able to:
explain input , output , and processing hardware.
identify the different types of printer.
tell about the computer software and its types.
write about the application software and its types.

Let's Update

. Charles Babbage in 1833 invented all the parts that are now used for the
modern computer. But the first ‘modern’ computer was invented only 120
years later.

. The Z1 was the first fully operational digital computer developed by
KonradZuse in 1936.

. In 1939, KonardZuse created the Z2 as the first  electro-mechanical
computer in the world.

Introduction

A computer hardware represents the physical components of a computer
that can be seen and touched. Input devices like keyboard, mouse, output
devices like printer, monitor, secondary storage devices like hard disk, CD,
DVD, internal components like microprocessor, mother board etc. are the
computer hardware. The computer software is a set of programs, which is
designed to perform a well-defined function. A program is a sequence of
instructions written to solve a particular problem.

Introduction to Computer Hardware and software 49