1. Basics Of Computers
VIVEK KUMAR SINGH

2. Introduction to Computers
A Desktop Machine
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Introduction to Computers

3. Introduction to Computers
A Computer System
User
Hardware
Software
User
Software
Hardware
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4. A Computer System (Contd.)
In general, a computer is a machine which accepts data, processes it and returns new information as output.
Processing
Data
Information
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5. Introduction to Computers
Software
Software is set of programs (which are step by step instructions) telling the computer how to process data.
Software needs to be installed on a computer, usually from a CD.
Softwares can be divided into two groups:
- System SW
- Application SW
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Introduction to Computers

6. Introduction to Computers
Software (Contd.)
System Software
It controls the overall operation of the system.
It is stored in the computer's memory and instructs the computer to load, store, and execute an application.
Examples: Operating System (OS), Translators
DOS, Windows, Unix etc.
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7. Introduction to Computers
Software (Contd..)
Application Software
They are Softwares written to perform specific tasks.
The basic types of application software are:
word processing, database, spreadsheet, desktop publishing, and communication.
Examples: MSOffice, Tally, MSOutlook,
ISBS, MODBANKER BANKSOFT
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8. Advantages of Using Computers
Speed: Computers can carry out instructions in less than a millionth of a second.
Accuracy : Computers can do the calculations without errors and very accurately.
Diligence : Computers are capable of performing any task given to them repetitively.
Storage Capacity : Computers can store large volume of data and information on magnetic media.
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9. History of Evolution Of Computers
Two Eras:
Mechanical Era (Before 1945)
Electronic Era ( )
Can be divided into generations.
First Generation (1945 – 1954)
Second Generation (1955 – 1964)
Third Generation (1965 – 1974)
Fourth Generation ( )
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10. Introduction to Computers
Types of Computers
On the basis of Computing Power & Size:
Laptop / Palmtop
Micro Computer / Desktop
Mini Computer / Mainframe
Super Computer
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11. Introduction to Computers
Language of Computers
Computers only understand the electronic signals.
Either Current is flowing or not.
Current Flowing : ON
Current Not Flowing : OFF
Binary Language
ON : 1
OFF : 0
Bit, Byte, KB, MB, GB
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12. Introduction to Computers
Computer Network
A Computer Network is interconnection of Computers to share resources.
Resources can be : Information, Load, Devices etc.
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13. Types Of Computer Networks
On the basis of Size:
Local Area Network (LAN)
Its a network of the computers locally i.e. in
one room, one building.
Wide Area Network (WAN)
Its a network of the computers spread widely
geographically.
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14. Benefits of Computer Networks
Information Sharing
Device Sharing
Load Sharing
Mobility
Fast Communication
Anywhere Anytime Banking
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15. Introduction to Computers
Internet
Internet is a huge network of computer networks.
Internet provides many services:
World Wide Web (www)
Remote Login (Telnet)
File Transfer (FTP)
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16. Introduction to Computers
End Of Session #1
ANY Queries ??????
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17. CPU ( Central Processing Unit)
The central processing unit (CPU), also
known as just a "processor”, is the "brain"
of your computer.
It contains various electronic circuits.
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18. Introduction to Computers
VDU (Monitor)
This is the television-like screen where the results of a computer's tasks are displayed.
Monitors come in all sizes, but most commonly they are either 15 or 17 inches
(measured diagonally from one corner of the screen to the opposite corner).
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19. Introduction to Computers
Keyboard
The keyboard looks like a typewriter.
It contains all the letters of the alphabet, numbers and some special symbols.
It operates like a typewriter keypad, but instead of moving an arm, which strikes the paper, it sends an electronic impulse to the computer, which displays a character on the monitor.
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20. Introduction to Computers
Mouse
Its a device that is used to control the computer.
A cable connects the mouse to the computer.
When the mouse is moved on a pad, called a
mouse pad, the cursor on the screen moves.
A cursor is a small symbol displayed on the
computer screen (normally a diagonal arrow that
is used as a pointer) that shows you what the
mouse is referencing on the screen.
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21. Introduction to Computers
Printer
A printer is designed to output information from a computer onto a piece of paper.
There are three kinds of printers:
dot matrix, laser, and inkjet.
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22. Introduction to Computers
Scanner
A scanner is a device used to copy an image off paper and convert it into a digital image, which can be saved as a computer file and stored on a hard drive.
Scanners can also use a special kind of technology called Optical Character Recognition (OCR) to read text from paper and save it as an editable document file
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23. Session # 2
Inside The CPU Cabinet

24. Introduction to Computers
A Look Inside.
Floppy CD
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25. Introduction to Computers
A Look Inside ..
power supply
CD-ROM drive
floppy drive
cards
hard drive
motherboard
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26. Introduction to Computers
A Look Inside…
Identify all the major components:
Power Supply
Motherboard
Memory
Card Slots
Cards (sound, video, network)
CPU, heatsink and fan
Drives (floppy, hard and CD-ROM)
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27. Introduction to Computers
A Look Inside….
RAM BANK
Card Slots (ISA & PCI)
CPU, Fan, Heatsink
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28. What these components do.
Power Supply – (heart) supplies power to all the circuitry and devices.
Motherboard – (body) acts as a manager for everything on the computer – connects all the other components together.
CPU – Central Processing Unit – (brain) this does all the work of computing.
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29. What these components do..
RAM – Random Access Memory – (short-term memory) holds data and program instructions that the computer is currently using.
Hard Drive – (long-term memory) holds all of the information that needs to be stored between uses of the computer.
Floppy and CD-ROM drives – (mouth/ears) allow you to give data to the computer and take data away from the computer.
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30. What these components do…
Card Slots – (fingers) Allows other components to be added to the computer.
Video card – (face) Does all of the processing necessary to get stuff looking nice on screen, quickly.
Sound card – (vocal cords) Allows sounds from HD or CD-ROM to be played.
Network Card – (telephone) allows computer to talk to other computers over a wire.
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31. Introduction to Computers
Power Supply
SMPS – Switch Mode Power Supply
Switching Transistors
Outputs + 5V, -5V, +12 V, -12 V
Typical Costs are:
ATX – Rs.700
Non ATX – Rs.300
Usually, SMPS comes with the CPU Cabinet.
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32. Introduction to Computers
Motherboard
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33. Introduction to Computers
CPU CU
A Single Chip
ALU
Memory
Registers
Examples: Intel Family – Pentium 4, 3, 2, Pentium,
XEON, Itanium
AMD Athlon, K62
IBM Cyrix
Motorola Series
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34. Introduction to Computers
RAM
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35. Introduction to Computers
Hard Drive
We won’t remove this.
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36. Introduction to Computers
Floppy Drive
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37. Introduction to Computers
CD-ROM Drive
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38. Introduction to Computers
Ribbon Cables
polarized
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39. Introduction to Computers
Video Card
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40. Introduction to Computers
Sound Card
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41. Introduction to Computers
Back of Computer
Remove these screws
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42. Introduction to Computers
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43. End of Session # 2 Queries???
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44. Introduction to Computers
CPU
The central processing unit or (CPU) is the "brain" of your computer. It contains the electronic circuits that cause the computer to follow instructions from memory.
The CPU contains three main parts, all housed
in a single package (Chip):
Control Unit (CU)
Arithmetic Logic Unit (ALU)
Memory
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BACK

45. Session # 3
Computer Peripherals

46. Introduction to Computers
Major Peripherals
Keyboard
Mouse
Hard Disk
Floppy Disk
CD ROM
Printer
Scanner
Joystick
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47. Introduction to Computers
Keyboard
Keypad contains:
Alphabets
Numbers
Special Symbols
Function Keys
qwert Keyboard (Typewriter Keyboard).
On key press it sends a code (ASCII Code) to the CPU.
Plug N Play device.
Typical Cost is Rs.300 – Rs.1200
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48. Introduction to Computers
Mouse
Pointing & Click Device.
Two / Three Buttons
Wheel / Optical Mouse
Normally Left Click – Select/ Run
Right Click – Popup Menu
Typical Cost is Rs.100 – Rs1000
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49. Introduction to Computers
Hard Disk
Magnetic Memory Device.
Non-removable storage device.
Several Circular Magnetic Disks are housed in a single case.
Data is stored as 1s & 0s.
Typical Capacity is 20 GB -80 GB
Typical Cost is Rs.2200 – Rs6000
Cost/Bit is Low.
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50. Introduction to Computers
Floppy Disk
Magnetic Memory Device.
Removable storage.
A single circular mylar plastic disk, coated with magnetic material is packed in a protective plastic casing.
Typical size is 3.5” & Capacity is 1.44MB
Typical Costs are:
Floppy Drive -- Rs.300
Floppy Disk -- Rs.10
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51. Introduction to Computers
CD ROM
Optical Device.
Removable Storage.
Read Only Memory.
Typical Capacity is 550 Mb – 800MB
Typical Costs are:
Drive Rs.1000
Disk Rs10 – Rs.35
Related Terms:
CD Writer
WORM
CD RW
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52. Introduction to Computers
Printer
Output Device, Produces Hard Copy
Types:
Dot Matrix
Inkjet
Laser
Typical Cost Ranges from Rs.3500 – Rs.2 lacs
Related Terms:
Impact – Non Impact
Ribbon, Cartridge, Toner, Duty Cycle
Major Vendors in India:
HP, Cannon, Samsung, TVS, Epson etc.
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53. Introduction to Computers
Scanner
Input Device, Converts a hard copy into a computer file.
Used to Scan Signatures, Photographs etc.
Optical Device.
Typical Cost Rs.4000 – Rs.75000
Major Vendors in India:
HP, Umax, Cannon
Nowadays Scanners with OCR produces editable documents.
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54. Introduction to Computers
End of Session #3
Queries???
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55. Session - 4 Overview of Operating System

56. What is Operating System
OS is system software, which may be viewed as collection of software consisting of procedures for operating the computer.
It provides an environment for execution of programs (application software).
It’s an interface between user & computer.
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57. Computer Machine (Hardware)
User / Programmer
Operating System
Human Understandable Language (High Level Language)
Machine Language (Low Level Language)
Computer Machine (Hardware)
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58. Introduction to Computers
Types of OS
Multiprogramming OS
Multitasking/Multiprocessing
Multiuser OS
Time Sharing OS
Real Time OS
Distributed OS
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59. A Second Classification
This Classification is based on the type of interface Operating System provides for the user to work in.
Character User Interface (CUI)
The User has to type the commands on the command prompt to get the work completed.
Ex. DOS, UNIX.
Graphical User Interface (GUI)
The User need not type any commands. He/She just point and clicks on the desired Icon to get the work done.
Ex. Windows (9X, XP, NT, 2000), Linux.
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60. Introduction to Computers
Functions of OS
File Management
Memory Management
Process Management
Device Management
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61. Introduction to Computers
Types of Processing
Serial Processing
The job is processed at the time when it is submitted.
Batch Processing
The similar jobs are bunched together and are kept for processing at an later time.
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62. Introduction to Computers
MS-DOS Overview
MS-DOS is an acronym for MicroSoft Disk Operating System
It is a CUI based operating system.
It provides user with a command prompt (generally called as C:\) where various command could be typed.
When one operates in the DOS environment, one interacts with the command interpreter, which interprets the commands given by user.
It provides an environment for execution of various application programs like MS-Word, MODBANKER, ISBS etc.
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63. Introduction to Computers
What is Command
It is a string of characters which tells the computer what to do.
When one types commands to a computer, one is conversing with the operating system's command interpreter.
For example, to copy a file called file.txt from the 3-1/2" floppy drive to the hard drive, one could type
C:\> copy a:\file.txt c:\
The word "copy" is a DOS command which causes files to be copied from one location to another
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64. Entering the DOS Environment
If the OS is DOS then the system will directly show prompt (C:\>)
If the OS is windows one must either terminate the Windows environment, or open a DOS shell within the Windows environment.
Ist Method: Terminating Windows Environment
Select “Restart in MS-DOS Mode” from Shut Down in Start Menu.
IInd Method: Opening DOS Shell in Windows
Select Start>Programs>Accessories>Command Prompt (XP)
Start>Programs>Accessories>MS-DOS Prompt (98)
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65. Introduction to Computers
Files and Directory
Files
A file is a collection of Records.
It is the smallest unit of File System (Storage) in a computer.
Any document created using computer is a file. This document could either be a letter, any excel sheet, any image or even a database.
Directory
A collection of files is directory (in DOS) or folder (in Windows)
It is analogous to the Office Folder which contains various documents.
A directory/folder eases the management of related files/ documents, like the various circulars related to personnel could be placed in a directory called “personnel” and all the circulars related to loans could be placed in a directory called “loans”.
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66. Introduction to Computers
Filenames in DOS?
The filename in DOS have the following format.
<name>.<ext>
It has two parts the name and the extension.
The name could be of 8 characters and the extension of 3 characters.
The filename can contain alphabets and numbers. It cannot contain any special character other than underscore (_) and also no spaces.
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67. Organization of files in DOS
The DOS file system is a hierarchical file system.
Files are collected into directories, and directories may contain both files and other directories.
There is always a directory which is not contained by any other, called the root which is represented by the backslash '\' character.
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68. Organization of files in DOS (Contd.)
Concept of Path: Every file can be specified by enumerating all of the directories between the root and it, separated by the backslash '\' character, and appending the file name to the end.
The drive which contains the root is specified at the head of the path, separated from the root by a colon (':')
The hard drive is most commonly known as the C: drive, and the floppy drives are usually called A:(3-1/2 inch) and B: (5-1/4 inch).
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69. Organization of files in DOS (Contd.)/
circulars
loans
personnel
officer.txt
new.dat
january
february
retire.txt
abc.txt
Fig. Hierarchical Structure of Files
rest.txt
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70. Introduction to Computers
Some DOS Commands
dir: Listing of all the directories.
C:\> dir
cls: Clears the screen.
C:\> cls
copy con: Creates a file.
C:\> copy con <filename>
< Write your Contents Here>
Press Ctrl-Z (^Z) to finish writing.
Ex: C:\> copy con test.dat
Lets Make UCO a top class Bank.
Ctrl-Z (^Z)
1 file(s) copied. (A Message will be shown on the system)
This will create a file named test.dat having some data.
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71. Some DOS Commands (Contd.)
edit: Edits a file.
C:\> edit <filename>
This will open a editor window where the contents of file can be seen. These contents could also be edited here and on saving, the contents of file will change.
type: Displays the content of a file.
C:\> type <filename>
This will display the contents of file on the computer. The contents of file could only be viewed but could not be changed, as in the case of edit.
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72. Some DOS Commands (Contd.)
md: Make Directory.
C:\> md (directory name>
This will create a directory with the specified name.
cd: Change Directory.
C:\> cd (directory name>
This will change the directory from current directory to the specified directory.
rd: Remove Directory.
C:\> rd (directory name>
If the directory is needed to be removed permanently from the computer, use this command. For this command to be executed it is necessary that the directory should be empty and user should be on a directory above it.
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73. Some DOS Commands (Contd.)
copy: Copies a file.
C:\> copy <source> <destination>
This will copy the file from the source location to the specified destination. The command creates a copy of the file on the destination i.e. the file would be found on both the location.
move: Moves a file.
C:\> move <source> <destination>
This will move the file from the source location to the specified destination. The file from the source location would be removed and would be moved to the destination.
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74. Some DOS Commands (Contd.)
ren: Renames a file.
C:\> ren <old filename> <new filename>
This will change the name (rename) of the file to a new name as specified.
del: Deletes a file.
C:\> del <filename>
This will delete the file permanently from the system.
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75. Introduction to Computers
Overview of Windows
Windows is an GUI based operating system.
It is also developed by Microsoft Corporation, which is headed by Mr. Bill Gates.
Over the years the Microsoft have evolved various versions of Windows. Win95, Win98, Win2000, Win ME, Win NT, Win XP.
It gives user a handy environment where he doesn’t have to remember and learn the syntaxes of various commands as is the case in DOS.
The user can just point and click on the Icons provided to him on the screen.
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76. Introduction to Computers
Folders and Documents
Folders are a way to organize your documents within drives in Windows as are the directories in DOS.
A document is each thing that you create on a computer. A document can be made using any type of software.
Now click on the folder “From your Teacher”
Then click on the Document “Welcome to Class”
Explain the software program that was used to create this document.
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77. Introduction to Computers
End of Session #4
Queries???
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78. Introduction to Computers
QUIZ
1. Name any four devices of a Computer.
Keyboard, Mouse, Scanner, Light Pen.
2. What is the job of CPU?
Central Processing Unit controls and coordinates all the activities of the computer.
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79. Introduction to Computers
QUIZ
3. What is the unit of measuring the speed of the processor?
Mega Hertz or Kilo Hertz ( No. of CPU Cycles/second)
4. What is a computer network?
It is interconnection of computers to make a LAN,MAN or WAN.
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80. Introduction to Computers
QUIZ
5. Name any three storage devices.
Hard Disk, Magnetic Tape, Compact Disk.
6. What is command to create directory?
C:\>MD <<dir-name>>
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81. Introduction to Computers
QUIZ
7. What is Internet?
It is the network of networks.
8. What are different types of printers?
Dot Matrix Printer, Inkjet
Laser
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82. Introduction to Computers
QUIZ
9.What is the use of Scanner?
It is used to copy the real image on paper to be stored as digital image in the computer.
10. Why Operating system is required?
It is required to provide the interface between the user and the computer.
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83. Introduction to Computers
QUIZ
11. What is the difference between Primary Storage and Secondary Storage?
Primary Storage is temporary storage, fast and costly.
Secondary storage is permanent, slow and
cheap.
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84. Introduction to Computers
QUIZ
12. What is MODEM. Why it is required?
It is Modulator Demodulator. It is used to connect the PC to the Internet using Analog Telephone Lines.
13. What is the maximum length of file name in DOS?
First Name- 8 characters, Last Name- 3 characters.
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85. Introduction to Computers
QUIZ
14. What is the command in DOS to see the contents of the file?
C:\> Type<<File Name>>
15. What are the two types of Software?
Systems Software
Application Software
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