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Computer Science For BS, Slides of Computer Science

Punjabi University Computer Science

Chapters of BS computer science

Typology: Slides

2018/2019

Uploaded on 12/24/2021

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This book is compiled for all

BS/ADP disciplines. This book

includes first 10 chapters (from

page 1 to 205) are related to

computer concepts and other

chapters are related to the

Windows 7, MS office 2010

(Word, Excel, PowerPoint,

Access), and InPage 2000 with

practical.

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Download Computer Science For BS and more Slides Computer Science in PDF only on Docsity!

This book is compiled for all

BS/ADP disciplines. This book

includes first 10 chapters (from

page 1 to 205) are related to

computer concepts and other

chapters are related to the

Windows 7, MS office 2010

(Word, Excel, PowerPoint,

Access), and InPage 2000 with

practical.

Chapter 1 Introduction to Computers

INTRODUCTION TO COMPUTER

What is Computer?

Chapter 1 - Introduction to Computer

What is Computer?

“Computer” derived from “compute” → means to calculate
In past, computer was normally considered to be a calculating device used to perform arithmetic operations
But today, computers are used in every field of life to solve problems of different kinds
Definition of Computer
- A computer is an electronic machine that is used to solve different kinds of problems according to a set of instructions given to it
Function of computer
- Accepts data and instructions (as input) and stores them in its own memory
- Processes or manipulates data according to given instructions and produces information (known as output)
- Stores information permanently on storage devices for later use
- Retrieves information from storage devices when required

Data & Information Data

Word ‘data’ refers to facts concerning things, people, objects, events, etc.
A collection of raw facts and figures → data
Word ‘raw’ means unprepared or unprocessed
Data may consist of text, numbers, images, audio, and video
Data is collected for different purposes
It does not give clear and proper meanings
- It cannot be used directly for decision-making
Example → A list of class students, showing students roll numbers, names, obtained marks, etc. Information
Processed data
Processed data (information) gives clear and proper meanings
- It can be used for decision-making

Data Processing

A process to convert data into information
Different operations are performed on data to convert it into useful information - Operations → arithmetic, data sorting, and data formatting
Data can be processed manually or by using a computer
Today, data is processed using a computer
Data and instructions are given to computer, It processes data according to given instructions and converts into required information or results

Characteristics of Computer Speed

High-speed electronic device
A computer can perform billions or trillions of operations or tasks per second
- Operations → arithmetic & sorting operations, displaying images, recording audio/video, playing music, and showing video or movie
Speed of a computer → in microseconds or nanoseconds
Usually, measured in Mega Hertz (MHz) or Giga Hertz (GHz)
Different computers have different speeds Accuracy
Computer does not make any kind of mistakes in calculations
It processes data and produces a 100% accurate result
Accuracy of result depends upon correct input data and set of instructions given to computer - If any mistake in input data → computer does not produce an accurate result
Computer can perform billions or trillions of operations in one second without any error

Characteristics of Computer Reliability

Electronic components in a modern computer have a very low failure rate
Modern computer can perform complicated calculations without creating any problem
In general, computers are very reliable and do all tasks accurately
Many personal computers have never needed a service call
Communication networks are also very reliable and generally available whenever needed
Nowadays, all large industries and organizations/companies are dependent on computers and their entire business is running through computers → have blindly trust in computers Consistency
People often have difficulty to repeat the same actions again and again in same way and to get the same result - For example, a lecturer feels difficulty to repeat a lecture in a classroom again and again
A computer can repeat same actions consistently (again and again) without losing its concentration - To run a spell checker (built into a word processor) for checking spelling in a document - To play multimedia animation for training purposes - To deliver a lecture through a computer in a classroom etc.
A computer will carry out the activity in an exact manner every time

Characteristics of Computer Versatility

Versatility refers to capability of a computer to perform different kinds of tasks with same accuracy & efficiency
Different types of tasks can be performed through computer
- At one moment we are playing a game on computer, the next moment we are composing and sending an e-mail, etc.
- In colleges and universities, computers are used to deliver lectures to students
That is why computers are being used in every field of life such as universities/colleges, hospitals, banks, offices, hotels, at homes, industries for manufacturing products, etc. Multitasking
A computer has the capability of multitasking
A user can perform multiple tasks on computer at the same time
Example → a user can print a document on printer, while listening to naats.

Characteristics of Computer Communication

A computer has capability of communicating with other computers in a computer network
Nowadays, computers are mostly used for exchanging messages or information through computer networks all over the world - Example → information can be received or sent through Internet with the help of computers Diligence
A computer can continuously work for hours without creating any error
It does not get tired while working
After hours of work, it performs operations with same accuracy and speed as first one No Feelings
A computer has no feelings or emotions
It detects objects based on the instructions given to it
Based on our feelings, taste, knowledge, and experience we can make certain decisions and judgments in our daily life
On the other hand, a computer cannot make such judgments on its own
Its judgments are totally based on the instructions given to it

Types of Computers

Chapter 1 - Introduction to Computer

Analog Computers

Word “analog” means continuously varying in quantity
Analog computers accept input data in continuous form and output is obtained in the form of graphs
These computers accept input and give output in the form of analog signals
Output is measured on a scale
Examples of analog data → voltage, current, sound, speed, temperature, pressure, etc. values - These values continuously increase and decrease
Analog computers are used to measure continuous values
Analog computers are usually built for special purposes
They have very high-speed computing elements used to process physical quantities
Analog computers have low memory size and have fewer functions

Digital Computers

Word “digital” means discrete
It refers to a binary system, which consists of only two digits, i.e. 0 and 1
Digital data consists of binary data represented by OFF (low) and ON (high) electrical pulses
These pulses are increased and decreased in discontinuous form rather than in continuous form
In digital computers, quantities are counted rather than measured
A digital computer operates by counting numbers or digits and gives output in digital form
It represents data in digital signals 0 and 1 and then processes it using arithmetic and logical operations
Today most of the computers used in business, educational institutions, hospitals, offices, and at homes are digital computers - Examples → IBM PC and Apple Macintosh - Calculators, digital watches, digital scoreboards, and digital thermometers

Hybrid Computers

Combined features of both analog and digital computers
These computers contain both digital and analog components
In hybrid computers, users can process both continuous (analog) and discrete (digital) data
These are special-purpose computers
These are very fast and accurate
These are used in scientific fields
In hospitals, these are used to watch the patient’s health condition in ICU (Intensive Care Unit)
These are also used in telemetry, spaceships, missiles, etc.

Computer Science For BS, Slides of Computer Science

Related documents

Partial preview of the text

Download Computer Science For BS and more Slides Computer Science in PDF only on Docsity!

This book is compiled for all

BS/ADP disciplines. This book

includes first 10 chapters (from

page 1 to 205) are related to

computer concepts and other

chapters are related to the

Windows 7, MS office 2010

(Word, Excel, PowerPoint,

Access), and InPage 2000 with

practical.

Chapter 1

Introduction to Computers

What is Computer?

Types of Computers