Module 2 : Part 2 INTRODUCTION TO HARDWARE & SOFTWARE INTRODUCTION TO HARDWARE & SOFTWARE

Module 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 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 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 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 Operating System is loaded System configuration is accomplished System Utilities are loaded Users are authenticated Starting the Computer

Step 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) 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 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 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 Loads System utilities are loaded into memory –Volume control –Antivirus software –PC card unplugging utility

Step 6: Users Authentication Authentication or user login occurs –User name –Password The user interface starts, enabling user interaction with computer programs

OS  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 Multitasking

OS  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 Memory least recently used data or program instructions page swapped out swap file Virtual memory management hard disk page swapped in most recently transferred data or program instructions memory

OS  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 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 Interface Command-line: –The user is required to type keywords or commands in order to enter data or give instructions

Menu-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): –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 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 Software

Personal Productivity Word Processing Spreadsheets Address Books Multimedia/Graphics Desktop Publishing Photo Editing 3D Rendering Internet Web Browsers Home/Education Personal Finance Tax Preparation Reference Games General Purpose applications are applications used by many people to accomplish frequently performed tasks General-Purpose Applications

Microsoft Office WordPerfect Office 12 Lotus SmartSuite Word processing Microsoft WordWordPerfectWord Pro SpreadsheetMicrosoft ExcelQuattro ProLotus DatabaseMicrosoft AccessParadoxLotus Approach Presentation Graphics Microsoft PowerPoint Corel Presentations Freelance Graphics Personal information managers Microsoft OutlookCorel CentralLotus Organizer Software Suites

System 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® 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 Version

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

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