z Comp-Intro

7/31/2019 z Comp-Intro

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Session - 1

Basics Of Computers



6/20/2012 Introduction to Computers 2

A Desktop Machine




A Computer System

• Hardware

• Software

• User

Hardware

Software

User




Software

• Software is set of programs (which are step bystep instructions) telling the computer how toprocess data.

• Software needs to be installed on a computer,usually from a CD.

• Softwares can be divided into two groups:

- System SW- Application SW




Software (Contd.)

System Software

• It controls the overall operation of the system.

• It is stored in the computer's memory andinstructs the computer to load, store, andexecute an application.

• Examples: Operating System (OS), Translators

DOS, Windows, Unix etc.




Software (Contd..)

Application Software

• They are Softwares written to perform specifictasks.

• The basic types of application software are:

word processing, database, spreadsheet,desktop publishing, and communication.

Examples: MSOffice, Tally, MSOutlook,

ISBS, MODBANKER BANKSOFT




Advantages of Using Computers

• Speed: Computers can carry out instructions in lessthan a millionth of a second.

• Accuracy : Computers can do the calculations withouterrors and very accurately.

• Diligence : Computers are capable of performing anytask given to them repetitively.

• Storage Capacity : Computers can store largevolume of data and information on magnetic media.




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 - )




Types of Computers

On the basis of Computing Power & Size:

• Laptop / Palmtop

• Micro Computer / Desktop

• Mini Computer / Mainframe• Super Computer




Language of Computers

• Computers only understand the electronicsignals.

Either Current is flowing or not.

• Current Flowing : ON

• Current Not Flowing : OFF

• Binary Language

• ON : 1

• OFF : 0

• Bit, Byte, KB, MB, GB




Computer Network

• A Computer Network is interconnection ofComputers to share resources.

• Resources can be : Information, Load,Devices etc.




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.




Benefits of Computer Networks

• Information Sharing

• Device Sharing

• Load Sharing

• Mobility

• Fast Communication

• Anywhere Anytime Banking




Internet

• Internet is a huge network of computer networks.

• Internet provides many services:

– Email

– World Wide Web (www)

– Remote Login (Telnet)

– File Transfer (FTP)




End Of Session #1

ANY Queries ??????




CPU ( Central Processing Unit)

• The central processing unit (CPU), alsoknown as just a "processor”, is the "brain"

of your computer.

• It contains various electronic circuits.




VDU (Monitor)

• This is the television-like screen where the resultsof a computer's tasks are displayed.

• Monitors come in all sizes, but most commonlythey are either 15 or 17 inches

(measured diagonally from one corner of the

screen to the opposite corner).




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, butinstead of moving an arm, which strikes the

paper, it sends an electronic impulse to thecomputer, which displays a character on themonitor.




• 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 amouse pad, the cursor on the screen moves.

• A cursor is a small symbol displayed on the

computer screen (normally a diagonal arrow thatis used as a pointer) that shows you what themouse is referencing on the screen.

Mouse




Printer

• A printer is designed to output informationfrom a computer onto a piece of paper.

• There are three kinds of printers:

dot matrix, laser, and inkjet.




Scanner

• A scanner is a device used to copy an image offpaper and convert it into a digital image, whichcan be saved as a computer file and stored on a

hard drive.

• Scanners can also use a special kind oftechnology called Optical Character Recognition(OCR) to read text from paper and save it as aneditable document file



Session # 2

Inside The CPU Cabinet




A Look Inside.

Floppy

CD




power

supply

hard

drive

motherboard

A Look Inside ..

CD-ROM

drive

floppydrive

cards




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)




What these components do.

• Power Supply – (heart) supplies power to all the circuitryand devices.

• Motherboard – (body) acts as a manager for everything

on the computer – connects all the other componentstogether.

• CPU – Central Processing Unit – (brain) this does all the

work of computing.




What these components do..

• RAM – Random Access Memory – (short-termmemory) holds data and program instructionsthat the computer is currently using.

• Hard Drive – (long-term memory) holds all of theinformation that needs to be stored betweenuses of the computer.

• Floppy and CD-ROM drives – (mouth/ears) allowyou to give data to the computer and take dataaway from the computer.

h h d




What these components do…

• Card Slots – (fingers) Allows other components to

be added to the computer.

• Video card – (face) Does all of the processingnecessary to get stuff looking nice on screen,

quickly.

• Sound card – (vocal cords) Allows sounds fromHD or CD-ROM to be played.

• Network Card – (telephone) allows computer totalk to other computers over a wire.




Power Supply

SMPS – Switch Mode Power SupplySwitching 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.




Motherboard




CPU

Examples: Intel Family – Pentium 4, 3, 2, Pentium,

XEON, ItaniumAMD -- Athlon, K62IBM -- CyrixMotorola -- 68000 Series

CU

ALU

MemoryRegisters

• A Single Chip




RAM




Hard Drive

We won’t remove this.




Floppy Drive




CD-ROM Drive




Ribbon Cables

polarized




Video Card




Sound Card




Back of Computer

Remove these screws




End of Session # 2

Queries???




CPU

• The central processing unit or (CPU) is the "brain"of your computer. It contains the electronic circuitsthat cause the computer to follow instructionsfrom memory.

• The CPU contains three main parts, all housed

in a single package (Chip):

– Control Unit (CU)

– Arithmetic Logic Unit (ALU)

– Memory

BACK



Session # 3

Computer Peripherals




Major Peripherals

• Keyboard

• Mouse

• Hard Disk

• Floppy Disk• CD ROM

• Printer

• Scanner

• Joystick




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




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




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.




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

CD ROM




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




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.




Scanner

• Input Device, Converts a hard copy into acomputer 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 produceseditable documents.




End of Session #3

Queries???



Session - 4

Overview of Operating System




What is Operating System

OS is system software, which may be viewed ascollection of software consisting of procedures foroperating the computer.

It provides an environment for execution of programs(application software).

It’s an interface between user & computer.




Computer Machine

(Hardware)

User / Programmer

Operating System

Human Understandable Language(High Level Language)

Machine Language(Low Level Language)




Types of OS

Multiprogramming OS

Multitasking/Multiprocessing

Multiuser OS

Time Sharing OS

Real Time OS

Distributed OS




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 thecommand 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.




Functions of OS

File Management

Memory Management

Process Management

Device Management




Types of Processing

Serial Processing

The job is processed at the time when

it is submitted.

Batch Processing

The similar jobs are bunched together andare kept for processing at an later time.




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 thecommand interpreter, which interprets the commands given by user.

It provides an environment for execution of various application programs

like MS-Word, MODBANKER, ISBS etc.




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 conversingwith 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 becopied from one location to another




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, oropen a DOS shell within the Windows environment.

Ist Method: Terminating Windows Environment

Select “Restart in MS-DOS Mode” from Shut Down in StartMenu.

IInd Method: Opening DOS Shell in Windows

Select Start>Programs>Accessories>Command Prompt (XP)Start>Programs>Accessories>MS-DOS Prompt (98)




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 aletter, 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 thevarious 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”.




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 3characters.

The filename can contain alphabets and numbers. It cannotcontain any special character other than underscore (_) andalso no spaces.




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.




Organization of files in DOS (Contd.)

Concept of Path: Every file can be specified by enumeratingall 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 thepath, 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).

Organization of files in DOS (Contd.)




g ( )

/

circulars loans personnel

january february

retire.txt

rest.txt abc.txt

officer.txt new.dat

Fig. Hierarchical Structure of Files

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.




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. Thesecontents could also be edited here and on saving, the contents of file willchange.

type: Displays the content of a file.

C:\> type <filename>

This will display the contents of file on the computer. The contents of file couldonly be viewed but could not be changed, as in the case of edit.





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, usethis 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.





copy: Copies a file.

C:\> copy <source> <destination>

This will copy the file from the source location to the specified destination. Thecommand creates a copy of the file on the destination i.e. the file would befound 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. Thefile from the source location would be removed and would be moved to thedestination.

S DOS C d (C d )





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.

Overview of Windows




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 casein DOS.

The user can just point and click on the Icons provided to him on the

screen.

Folders and Documents




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.




End of Session #4

Queries???




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 coordinatesall the activities of the computer.




QUIZ

3. What is the unit of measuring the speed of theprocessor?

Mega Hertz or Kilo Hertz ( No. of CPU

Cycles/second)

4. What is a computer network?

It is interconnection of computers to make aLAN,MAN or WAN.

QUIZ




QUIZ

5. Name any three storage devices.

Hard Disk, Magnetic Tape, Compact Disk.

6. What is command to create directory?C:\>MD <<dir-name>>

QUIZ




QUIZ

7. What is Internet?

It is the network of networks.

8. What are different types of printers?Dot Matrix Printer, Inkjet

Laser



QUIZ




QUIZ

11. What is the difference between PrimaryStorage and Secondary Storage?

Primary Storage is temporary storage,fast and costly.

Secondary storage is permanent, slow and

cheap.

QUIZ




QUIZ

12. What is MODEM. Why it is required?

It is Modulator Demodulator. It is used toconnect 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- 3characters.

QUIZ



QUIZ

14. What is the command in DOS to see thecontents of the file?

C:\> Type<<File Name>>

15. What are the two types of Software?

Systems Software

Application Software

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