Session - 1 Basics Of Computers

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Session - 1Basics Of Computers
VIVEK KUMAR SINGH vivek_at_bhu.ac.in
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A Desktop Machine
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A Computer System
User

• Hardware
• Software
• User

Software
Hardware
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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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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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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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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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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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History of Evolution Of Computers

• Two Eras
• Mechanical Era (Before 1945)
• Electronic Era (1945 - )
• Can be divided into generations.
• First Generation (1945 1954)
• Second Generation (1955 1964)
• Third Generation (1965 1974)
• Fourth Generation (1975 - )

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Types of Computers

• On the basis of Computing Power Size
• Laptop / Palmtop
• Micro Computer / Desktop
• Mini Computer / Mainframe
• Super Computer

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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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Computer Network

• A Computer Network is interconnection of
  Computers to share resources.
• Resources can be Information, Load, Devices etc.

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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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Benefits of Computer Networks

• Information Sharing
• Device Sharing
• Load Sharing
• Mobility
• Fast Communication
• Anywhere Anytime Banking

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Internet

• Internet is a huge network of computer networks.
• Internet provides many services
• Email
• World Wide Web (www)
• Remote Login (Telnet)
• File Transfer (FTP)

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• End Of Session 1
• ANY Queries ??????

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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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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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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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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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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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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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Session 2

• Inside The CPU Cabinet

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A Look Inside.
Floppy
CD
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A Look Inside ..
power supply
CD-ROM drive
floppy drive
cards
hard drive
motherboard
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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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A Look Inside.
RAM BANK
CPU, Fan, Heatsink
Card Slots (ISA PCI)
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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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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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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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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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Motherboard
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CPU
CU

• A Single Chip

ALU
Memory Registers
Examples Intel Family Pentium 4, 3, 2,
Pentium,
XEON, Itanium AMD --
Athlon, K62 IBM --
Cyrix Motorola -- 68000
Series
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RAM
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Hard Drive
We wont remove this.
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Floppy Drive
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CD-ROM Drive
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Ribbon Cables
polarized
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Video Card
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Sound Card
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Back of Computer
Remove these screws
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(No Transcript)
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End of Session 2Queries???
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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

BACK
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Session 3
Computer Peripherals
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Major Peripherals

• Keyboard
• Mouse
• Hard Disk
• Floppy Disk
• CD ROM
• Printer
• Scanner
• Joystick

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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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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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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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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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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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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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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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End of Session 3

• Queries???

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Session - 4Overview of Operating System
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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).
• Its an interface between user computer.

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Computer Machine (Hardware)
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Types of OS

• Multiprogramming OS
• Multitasking/Multiprocessing
• Multiuser OS
• Time Sharing OS
• Real Time OS
• Distributed OS

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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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Functions of OS

• File Management
• Memory Management
• Process Management
• Device Management

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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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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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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\gt 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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Entering the DOS Environment

• If the OS is DOS then the system will directly
  show prompt (C\gt)
• 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 StartgtProgramsgtAccessoriesgtCommand
  Prompt (XP)
• StartgtProgramsgtAccessoriesgtMS-DOS Prompt (98)

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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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Filenames in DOS?

• The filename in DOS have the following format.
• ltnamegt.ltextgt
• 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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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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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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Organization of files in DOS (Contd.)
circulars
loans
personnel
officer.txt
new.dat
january
february
retire.txt
abc.txt
rest.txt
Fig. Hierarchical Structure of Files
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Some DOS Commands

• dir Listing of all the directories.
• C\gt dir
• cls Clears the screen.
• C\gt cls
• copy con Creates a file.
• C\gt copy con ltfilenamegt
• lt Write your Contents Heregt
• Press Ctrl-Z (Z) to finish writing.
• Ex C\gt 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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Some DOS Commands (Contd.)

• edit Edits a file.
• C\gt edit ltfilenamegt
• 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\gt type ltfilenamegt
• 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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Some DOS Commands (Contd.)

• md Make Directory.
• C\gt md (directory namegt
• This will create a directory with the specified
  name.
• cd Change Directory.
• C\gt cd (directory namegt
• This will change the directory from current
  directory to the specified directory.
• rd Remove Directory.
• C\gt rd (directory namegt
• 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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Some DOS Commands (Contd.)

• copy Copies a file.
• C\gt copy ltsourcegt ltdestinationgt
• 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\gt move ltsourcegt ltdestinationgt
• 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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Some DOS Commands (Contd.)

• ren Renames a file.
• C\gt ren ltold filenamegt ltnew filenamegt
• This will change the name (rename) of the file
  to a new name as specified.
• del Deletes a file.
• C\gt del ltfilenamegt
• This will delete the file permanently from the
  system.

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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
  doesnt 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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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.

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End of Session 4

• Queries???

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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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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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QUIZ

• 5. Name any three storage devices.
• Hard Disk, Magnetic Tape, Compact Disk.
• 6. What is command to create directory?
• C\gtMD ltltdir-namegtgt

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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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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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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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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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QUIZ

• 14. What is the command in DOS to see the
  contents of the file?
• C\gt TypeltltFile Namegtgt
• 15. What are the two types of Software?
• Systems Software
• Application Software