Module 2 : Part 2Module 2 : Part 2

INTRODUCTION

TO HARDWARE & SOFTWARE

INTRODUCTION

TO HARDWARE & SOFTWARE

Module ObjectivesModule Objectives

• At the end of the module, students should be able to: – identify the two major components of operating system

software– understand why a computer isn’t useful without an

operating system– describe the five basic functions of an operating system– describe what happens when the computer is turn on – state three major types of user interfaces– describe the concept of software versions and systems

requirements– identify the differences between types of software

Operating System SoftwareOperating System Software

• System software includes all of the programs needed to keep a computer and its peripheral devices running smoothly

• Two major components of system software are:– Operating systems (OS)– System utilities

The Operating System (OS):The Computer’s Traffic CopThe Operating System (OS):The Computer’s Traffic Cop

• The operating system is a set of programs that perform certain basic functions with a specific type of hardware

• Among the functions of the OS are:– Starting the computer

– Managing programs

– Managing memory

– Handling messages from input and output devices

– Enabling user interaction with the computer

OS Starting the ComputerOS Starting the Computer

• Booting – The process of loading or reloading the operating system into the computer’s memory

• The booting processes are:– Cold boot – Loads the OS when the power

is turned off– Warm boot – Reloads the OS when the

computer is already on

The step-by-step booting process (click for each step):

BIOS is loaded

Power-on Self-test is completed

OperatingSystem is

loaded

System configuration

isaccomplishedSystem

Utilities areloaded

Users areauthenticated

Starting the ComputerStarting the Computer

Step 1: The BIOS and Setup ProgramStep 1: The BIOS and Setup Program

• ROM (Read Only Memory) – Permanent and unchanging memory

• BIOS (Basic Input/Output System) – The part of the system software that includes the instructions that the computer uses to accept input and output

• Load – To transfer from a storage device to memory• ROM loads BIOS into the computer’s memory• Setup program – A special program containing settings

that control the computer’s hardware• The program can be accessed while the BIOS information

is visible

Step 2: The Power-On-Self-Test (POST)Step 2: The Power-On-Self-Test (POST)

• POST (Power-On-Self-Test) – A series of tests conducted on the computer’s main memory (random access memory or RAM), input/output devices, disk drives, and the hard disk

• BIOS conducts a POST to check the input/output system for operability

• The computer will produce a beeping sound and an error message will appear on the monitor if any problems are encountered

Step 3: The Operating System (OS) Loads

Step 3: The Operating System (OS) Loads

• BIOS searches for the OS• Settings in the CMOS (Complementary

Metal-Oxide Semiconductor) determine where to look for the OS

• The operating system’s kernel is loaded into the computer’s memory

• The OS takes control of the computer and begins loading system configuration information

Step 4: System ConfigurationStep 4: System Configuration

• Registry – A database that stores information about peripherals and software

• Peripheral – Device connected to a computer

• Driver – A utility program that makes peripheral devices function properly

• The system is configured from the operating system’s registry

• Drivers are loaded into memory

Step 5: System Utilities LoadsStep 5: System Utilities Loads

• System utilities are loaded into memory

– Volume control

– Antivirus software

– PC card unplugging utility

Step 6: Users AuthenticationStep 6: Users Authentication

• Authentication or user login occurs– User name– Password

• The user interface starts, enabling user interaction with computer programs

OS Managing ApplicationsOS Managing Applications

• Single-tasking operating systems run one application program at a time

• Multitasking operating systems have the ability to run more than one application program at a time

• Multitasking is accomplished by:

– A foreground application – The active program or program in use

– One or more background applications – Inactive program(s) or program(s) not in use

Background application

Foreground application

Example of MultitaskingExample of Multitasking

OS Managing MemoryOS Managing Memory

• Computers use memory to make processing more fluid

• The operating system allocates memory areas for each running program; it keeps programs from interfering with each other

• The operating system uses virtual memory as an extension of random access memory (RAM)

Managing Virtual MemoryManaging Virtual Memory

least recentlyused data or

program instructions

pageswapped

out

swap file

Virtual memorymanagement

hard diskpage

swapped in

most recentlytransferred data or

program instructions

memory

OS Handling Input and OutputOS Handling Input and Output

• Input and output devices generate interrupts, or signals, that tell the operating system that something has happened

• The OS provides interrupt handlers or mini-programs that begin when an interrupt occurs

• Interrupt request (IRQ) lines handle the communications between input/output devices and the CPU

• An IRQ conflict causes system instability when two devices try to use the same IRQ line

OS Providing the User InterfaceOS Providing the User Interface

• The user interface is that part of the operating system with which the user interacts with a computer

• User interface functions:

– Start application programs

– Manage disks and files

– Shut down the computer safely

Command-Line InterfaceCommand-Line Interface

• Command-line:– The user is required to type keywords or

commands in order to enter data or give instructions

Menu-driven User InterfaceMenu-driven User Interface

• Menu-driven:– Text-based menus are used to show all of

the options available to the user

Graphical User Interface (GUI)Graphical User Interface (GUI)

• Graphical user interface (GUI):

– Uses graphics to create a desktop environment

– Icons (small pictures) represent computer resources

– Programs run within on-screen windows

System Utilities: Tools for Housekeeping

System Utilities: Tools for Housekeeping

• System utilities are programs that help the operating system manage the computer system’s resources

• Types of utilities:

– Backup software

– Antivirus software

– Disk scanning

– Disk de-fragmentation

– File management

– File-searching software

– File compression

• Application software refers to programs that enable the user to be productive when using the computer

Application SoftwareApplication Software

Personal Productivity

Word Processing

Spreadsheets

Address Books

Multimedia/Graphics

Desktop Publishing

Photo Editing

3D Rendering

Internet

Web Browsers

E-Mail

Home/Education

Personal Finance

Tax Preparation

Reference

Games

• General Purpose applications are applications used by many people to accomplish frequently performed tasks

General-Purpose ApplicationsGeneral-Purpose Applications

Microsoft Office

WordPerfect Office 12

Lotus SmartSuite

Word processing

Microsoft Word WordPerfect Word Pro

Spreadsheet Microsoft Excel Quattro Pro Lotus 1-2-3

Database Microsoft Access Paradox Lotus Approach

Presentation Graphics

Microsoft PowerPoint

Corel Presentations

Freelance Graphics

Personal information managers

Microsoft Outlook Corel Central Lotus Organizer

Software SuitesSoftware Suites

System RequirementsSystem Requirements

• System requirements refers to the minimum level of equipment needed to run a program

– Platform– PC or MAC– Microprocessor– Drive– 3.5 Floppy or CD-ROM– RAM– Available hard disk space

Sample Minimum System Requirements• IBM compatible PC with a 486 PC processor or better (Pentium®

recommended)• Microsoft Windows® 95• 12 MB RAM (16 MB recommended)• Hard disk space (standard installation approx. 100 MB)• CD-ROM drive (2x or better)• Mouse or other pointing device

• Software producers include a version number with their products

• Version numbers identify the release of the program being used

• Recent releases have numbers greater than earlier releases (Recent Ver. 6.0; Earlier Ver. 1.0)

– Whole numbers are major revisions (1.0, 2.0, 3.0, etc.)

– Decimal numbers refer to maintenance releases or updates and fixes (1.1, 1.2, 1.3, etc.)

Software VersionSoftware Version

Commercial Software, Shareware, Freeware and Public Domain Software

Commercial Software, Shareware, Freeware and Public Domain Software

• Most computer software is copyrighted

• Software piracy – Infringing on a program’s copyright– Copyrighted software can not be:

• Copied• Altered• Used on more than one computer

• Types of copyrighted software:– Commercial – Buy before using it– Shareware – Try it before you buy it– Freeware – Free software, but it can’t be copied and/or

sold

• Public domain software is not copyrighted. There are no restrictions on using, copying, altering, or selling the software Open Source

Commercial Software, Shareware, Freeware and Public Domain Software

Commercial Software, Shareware, Freeware and Public Domain Software

ReferencesReferences

• Slides adapted from course materials of Daley, B. “ Computers Are Your Future 2006, Complete Ed”. Prentice Hall, 2006.