COMPUTER SOFTWARECOMPUTER SOFTWARE

EDIT Module 1: Introduction to EDIT Module 1: Introduction to Information TechnologyInformation Technology

Think of a computer as a robot.

What do you want it to do?

We Want a Computer To:1. Read input data from source documents or secondary

storage.2. Process the data.3. Display the results. 4. Print the results.5. Store the results.6. Transmit the results.7. Protect itself and the data.8. Keep track of things that it is doing to restart.9. Count things to reflect performance. 10. Do multiple things at the same time.

For the computer to be able to For the computer to be able to perform all these requires the perform all these requires the user to instruct the computer user to instruct the computer

software to control the machinesoftware to control the machine

Why is this topic important

Hardware is the engine and software is the gas that makes it run.

To understand software concepts is to understand how real work gets done on computer-based systems within a business.

To understand software is to appreciate the specific details that must be addressed for a new computer-based application to be implemented.

Important Topics Major categories of software.

The importance of operating systems and related systems software.

The increasing importance of application packages.

Challenges to implement application packages.

The evolution of programming languages and the reason for so

many languages.

Computer Software

The detailed instructions that control

the operation of a computer system.

Provide tools to people. Intermediary between people and data. Manage the computer resources. Selecting appropriate software for an

enterprise is a key management decision.

Overview of Computer SoftwareOverview of Computer Software

General- Purpose Programs

General- Purpose Programs

Application- Specific

Programs

Application- Specific

Programs

System Management

Programs

System Management

Programs

System Development

Programs

System Development

Programs

Application Software

Application Software

Computer Software

Computer Software

System Software

System Software

Trends in Computer SoftwareTrends in Computer Software

FirstGeneration

FirstGeneration

SecondGeneration

SecondGeneration

ThirdGeneration

ThirdGeneration

FourthGeneration

FourthGeneration

FifthGeneration

FifthGeneration

User-Written ProgramsMachine Languages

Packaged ProgramsSymbolic Languages

Operating SystemsHigh-Level Languages

DBMS Fourth- Generation LanguagesMicrocomputer Packages

Natural & Object-Oriented

LanguagesMultipurpose

Graphic- Interface Network-enabled Expert-Assisted

Packages

Trend: Toward Easy-to-Use Multipurpose Network-Enabled ApplicationPackages for Productivity and Collaboration

Trend: Toward Visual or Conversational Programming Languages andTools

Application Software:Application Software:End User ApplicationsEnd User Applications

1) General Purpose Application Programs1) General Purpose Application Programs Software Suites – Microsoft OfficeSoftware Suites – Microsoft Office

– Word Processing - Word / Works / ClarisWord Processing - Word / Works / Claris– Spreadsheet – Excel / FoxPro / LotusSpreadsheet – Excel / FoxPro / Lotus– Database Managers - Access / Dbase/SybaseDatabase Managers - Access / Dbase/Sybase

Web Browsers – Internet Explorer / NetscapeWeb Browsers – Internet Explorer / Netscape Electronic Mail – MS Outlook / Express / Electronic Mail – MS Outlook / Express /

EudoraEudora Presentation Graphics – Power Point / FlashPresentation Graphics – Power Point / Flash

Application Software:Application Software:End User ApplicationsEnd User Applications

2) Application-Specific Programs2) Application-Specific Programs Application Software Packages support Application Software Packages support

managerial and operational uses:managerial and operational uses:– AccountingAccounting

– Transaction ProcessingTransaction Processing

– Customer Relationship ManagementCustomer Relationship Management

– Electronic CommerceElectronic Commerce

System Software:Computer System Management

1) System Management Programs• Operating System

- Resource Management

- File Management

- Task Management

• Network Management Programs• Database Management Systems• System Utilities

System Software:Computer System Management

2) System Development Programs• Programming Language

- BASIC / C++ / COBOL / JAVA/TURBO-PASCAL

• Programming Translators- Assemblers – translates assembler language- Compilers – translates high level language [translate

the program (source code) into machine code (object code), then execute the object code.]

Programming Languages

Machine LanguagesUse binary coded instructions

1001 10011100 1101

High Level LanguagesUse brief statements

Compute X = Y + Z

Markup LanguagesUse embeddedcontrol codes

Assembler LanguagesUse symbolic codedinstructions

LOD YADD Z

Fourth GenerationLanguagesUse natural statements

Object-OrientedLanguagesDefine objects thatcontain data and actions

Document.write(“Hi There”)

<H1>First heading</H><!ELEMENT Product (#Item | manuf)>

SUM THE FOLLOWINGNUMBERS

In short:In short:

SoftwareSoftware– Application vs. SystemApplication vs. System

Application SoftwareApplication Software– General purpose General purpose

applications for end applications for end usersusers

System SoftwareSystem Software– Manage hardware, Manage hardware,

software, network, data software, network, data resourcesresources

Operating SystemsOperating Systems– Five basic functions:Five basic functions:

» User interfaceUser interface

» Resource ManagementResource Management

» File ManagementFile Management

» Task ManagementTask Management

» Utilities for support Utilities for support servicesservices

Programming Programming LanguagesLanguages– Five major levels:Five major levels:

» Machine languageMachine language

» Assembler languageAssembler language

» High-level languageHigh-level language

» Fourth-GenerationFourth-Generation

» Object-OrientedObject-Oriented

Systems SoftwareSystems Software

Definition:Definition:– All programs related to coordinating All programs related to coordinating

computer operationscomputer operations ComponentsComponents

– Operating SystemOperating System– Utility programsUtility programs– Program language translatorsProgram language translators

Operating SystemOperating SystemHidden SoftwareHidden Software

Definition – provides access to all resourcesDefinition – provides access to all resources KernelKernel

– Manages the operating systemManages the operating system– Memory residentMemory resident– Loads set of programs that lies between applications Loads set of programs that lies between applications

software and the hardwaresoftware and the hardware– Fundamental software that controls non-resident portions of Fundamental software that controls non-resident portions of

the OS as neededthe OS as needed Booting – Loads the kernel into memoryBooting – Loads the kernel into memory

Operating SystemA software program that acts as an intermediary

between a user of a computer and the computer

hardware.

Exist because it is a reasonable way to solve the

problem of creating a usable computer by better

managing the computer resources.

The basis for standardization of application

software. (the platform)

Functions of an Operating SystemFunctions of an Operating SystemFunctions of an Operating SystemFunctions of an Operating System

ResourceManagement

ResourceManagement

TaskManagement

TaskManagement

UserInterface

UserInterface

File (Data)Management

File (Data)Management

Utilitiesand OtherFunctions

Utilitiesand OtherFunctions

Use of Use of hardware hardware resourcesresources

Use of Use of hardware hardware resourcesresources

Managing the Managing the accomplishment accomplishment of tasksof tasks

Managing the Managing the accomplishment accomplishment of tasksof tasks

Managing Managing Data and Data and Program FilesProgram Files

Managing Managing Data and Data and Program FilesProgram Files

Sort, Merge, Sort, Merge, Performance, Performance, etc.etc.

Sort, Merge, Sort, Merge, Performance, Performance, etc.etc.

Functions of OSFunctions of OS

Manage the computer’s resourcesManage the computer’s resources– CPUCPU– MemoryMemory– Disk drivesDisk drives– PrintersPrinters

Establish a user interfaceEstablish a user interface

Execute and provide services for applications Execute and provide services for applications softwaresoftware

Carries out all input and output operationCarries out all input and output operation

Multiprogramming - executing two or more programs concurrently using the same computer.

Multiprocessing - executing two or more instructions simultaneously in a single computer by using multiple central processing units.

Graphical User Interface (GUI) - part of the operating system that uses graphic icons to issue commands and make selections.

Operating System Functions

User InterfaceUser Interface

Facilitates communication between the user and Facilitates communication between the user and the operating systemthe operating system

Two formsTwo forms– Command lineCommand line

» Text-basedText-based» Key commandsKey commands» Examples: MS-DOS, UnixExamples: MS-DOS, Unix

– Graphical user interface (GUI)Graphical user interface (GUI)» Visual imagesVisual images» MenusMenus» Examples: Windows, Mac OS, LinuxExamples: Windows, Mac OS, Linux

UNIX Linux OS/2 Mac OS IBM MVS, VM

• DOS

• Windows .X

• Windows NT

Popular Operating Systems

OS is HiddenOS is Hidden

User interested in application User interested in application software to make the PC software to make the PC usefuluseful

Application software is Application software is platform specificplatform specific

User must be aware of the User must be aware of the type of OStype of OS

User should be aware of the User should be aware of the functions of OSfunctions of OS

What is the platform of your What is the platform of your system?system?

A common question posed to a A common question posed to a system vendor, manufacturer or even system vendor, manufacturer or even

the organization utilizing the the organization utilizing the system…..system…..

PlatformPlatform

Definition:Definition:Computer hardware and operating Computer hardware and operating system software that dictate what other system software that dictate what other software can runsoftware can run

E.g. WintelE.g. WintelIntel-based PC running on Intel-based PC running on

Microsoft WindowsMicrosoft Windows

Types of OSTypes of OS

Command lineCommand line

Single user PCSingle user PC

Network Operating System (NOS)Network Operating System (NOS)

Command-line: MS-DOSCommand-line: MS-DOS

Command-line interfaceCommand-line interface

Prompt – system is waiting for you to do Prompt – system is waiting for you to do somethingsomething

Key a commandKey a command

Not user-friendlyNot user-friendly

Single-user PC: Single-user PC: Microsoft WindowsMicrosoft Windows

Graphical user Graphical user interfaceinterface

Eases access to Eases access to the OSthe OS

Most new Most new computers come computers come with Windows with Windows already installedalready installed

Network Operating System Network Operating System NOSNOS

Designed to permit computers on a network Designed to permit computers on a network to share resourcesto share resources

ExamplesExamples– Windows 2000 ServerWindows 2000 Server– Novell Net WareNovell Net Ware

ProvidesProvides– Data securityData security– TroubleshootingTroubleshooting– Administrative controlAdministrative control

NOS FunctionsNOS Functions

Split between client and server computersSplit between client and server computers ServerServer

– File managementFile management

ClientClient– Requests to the serverRequests to the server– MessagingMessaging– Has own local OSHas own local OS

Makes the resources appear as if they are Makes the resources appear as if they are local to the client’s computerlocal to the client’s computer

Early Days of Windows OSEarly Days of Windows OS

Operating environment for MS-DOSOperating environment for MS-DOS

Shell – layer added between users Shell – layer added between users and DOSand DOS

Windows TodayWindows Today

Home/consumer marketHome/consumer market– Windows 95Windows 95– Windows 98Windows 98– Windows Millennium Edition (ME)Windows Millennium Edition (ME)

Corporate marketCorporate market– Windows NTWindows NT– Windows 2000Windows 2000

Windows XPWindows XP Pocket computers and Internet appliancesPocket computers and Internet appliances

– Windows CEWindows CE

What are the prominent features What are the prominent features of Windows?of Windows?

Prominent feature of Prominent feature of Windows: GUIWindows: GUI

On-screen picturesOn-screen pictures– IconsIcons– MenusMenus

» Pull downPull down» Pop upPop up

– Click to activate a Click to activate a command or functioncommand or function

FastFast EasyEasy IntuitiveIntuitive

Windows 95 and 98Windows 95 and 98

Self-contained OSSelf-contained OS DOS commands still availableDOS commands still available Start programs byStart programs by

– Start buttonStart button– Double clicking the iconDouble clicking the icon

Task bar permits movement between open Task bar permits movement between open programsprograms

Long file names up to 255 charactersLong file names up to 255 characters Plug and playPlug and play Object linking and embedding (OLE)Object linking and embedding (OLE)

Windows 98 AdditionsWindows 98 Additions

Internet / intranet browsingInternet / intranet browsing

Support for DVD and additional Support for DVD and additional multimedia componentsmultimedia components

Support for large hard drivesSupport for large hard drives

TV viewer and broadcast abilityTV viewer and broadcast ability

Wizards / Help AssistantWizards / Help Assistant

Improved Windows FeaturesImproved Windows Features

BackupBackup Interfaces with other softwareInterfaces with other software Networking featuresNetworking features SecuritySecurity Dr. WatsonDr. Watson

WindowsWindows

Helps reduce the cost of owning and Helps reduce the cost of owning and maintaining a PCmaintaining a PC

Windows MEWindows MEMillennium EditionMillennium Edition

Multimedia support -- Windows Media Player 7Multimedia support -- Windows Media Player 7 JukeboxJukebox

– Record music CDs as digital filesRecord music CDs as digital files Windows Movie MakerWindows Movie Maker

– Basic video editingBasic video editing Windows Image AcquisitionWindows Image Acquisition

– Scanner and digital cameraScanner and digital camera

Windows MEWindows MEMillennium EditionMillennium Edition

Reliability FeaturesReliability Features– System File ProtectionSystem File Protection– AutoUpdateAutoUpdate– System RestoreSystem Restore

Help CenterHelp Center Home Network SupportHome Network Support

– Wizard for connecting multiple computers and Wizard for connecting multiple computers and peripheralsperipherals

– Multiple users can share a single Internet Multiple users can share a single Internet connectionconnection

Windows NTWindows NTNew TechnologyNew Technology

Engineered for stabilityEngineered for stability Strong securityStrong security VersionsVersions

– NT WorkstationNT Workstation– NT ServerNT Server

DrawbacksDrawbacks– Lacks support for older Windows and MS-DOS Lacks support for older Windows and MS-DOS

software and hardwaresoftware and hardware– Complex to learn and useComplex to learn and use– Requires more memory and processing powerRequires more memory and processing power

Windows 2000Windows 2000

Stability featuresStability features Security featuresSecurity features Uses simple approach to hardware setup Uses simple approach to hardware setup

from Windows 98from Windows 98 VersionsVersions

– Windows 2000 Professional for individual usersWindows 2000 Professional for individual users– Windows 2000 for network serversWindows 2000 for network servers

Was intended for both the corporate and Was intended for both the corporate and home use, replacing Win NT and Win 98home use, replacing Win NT and Win 98

Windows 2000Windows 2000

ComplexComplex

Heavy demand for computer resourcesHeavy demand for computer resources

Improvements over windows NTImprovements over windows NT– Maintains user preferencesMaintains user preferences– Self-healing applications softwareSelf-healing applications software– Supports Windows 98 file structureSupports Windows 98 file structure– Uses plug and playUses plug and play– Provides improved support for laptopsProvides improved support for laptops

Windows XPWindows XP

Extends Windows ME and provides a Extends Windows ME and provides a more stable environmentmore stable environment

Two categoriesTwo categories – Network serverNetwork server

» 3 versions based upon network complexity3 versions based upon network complexity

– Desktop computerDesktop computer» 2 versions2 versions

Professional ClientProfessional Client Personal ClientPersonal Client

Windows CEWindows CE Consumer ElectronicsConsumer Electronics

Where usedWhere used Embedded systemsEmbedded systems

– Industrial controllersIndustrial controllers– RobotsRobots– Office equipmentOffice equipment– CamerasCameras– TelephonesTelephones– Home entertainment devicesHome entertainment devices– Automobile navigation systemsAutomobile navigation systems

Pocket PCPocket PC Internet appliance marketInternet appliance market

Windows CEWindows CE Consumer ElectronicsConsumer Electronics

Subset of WindowsSubset of Windows Less memoryLess memory

Smaller screensSmaller screens

Little or no file storageLittle or no file storage

Provides Internet connectivityProvides Internet connectivity

Mac OSMac OS

First First commercially commercially successful GUI successful GUI (1984)(1984)

Served as a Served as a model to other model to other GUI systemsGUI systems

UNIXUNIX

SupportsSupports– Multi-userMulti-user– Time-sharingTime-sharing

Character-based systemCharacter-based system Command-line interfaceCommand-line interface Runs on various processors and many Runs on various processors and many

types of computerstypes of computers Primary OS used on Internet serversPrimary OS used on Internet servers

LINUXLINUX

UNIX-like OSUNIX-like OS Open-source softwareOpen-source software

– Download it freeDownload it free– Make changesMake changes– Distribute copiesDistribute copies– Restriction – any changes must be freely Restriction – any changes must be freely

available to the publicavailable to the public PC SetupPC Setup

– PC comes with Windows installedPC comes with Windows installed– Install LINUX in a dual-boot configurationInstall LINUX in a dual-boot configuration

LINUXLINUX

Advantages over WindowsAdvantages over Windows– Extremely stableExtremely stable– Internet supportInternet support– Reinstallation is simplerReinstallation is simpler

DisadvantageDisadvantage– Scarcity of applicationsScarcity of applications

Large ComputersLarge Computers

Used by many people at onceUsed by many people at once OS works “behind the scenes” so users OS works “behind the scenes” so users

can share resources (hardware & can share resources (hardware & software)software)

OS must controlOS must control– Who gets access to resourcesWho gets access to resources– What keeps the programs from different What keeps the programs from different

users from getting mixed up with one users from getting mixed up with one anotheranother

Sharing MemorySharing Memory

Program must be in memory to be Program must be in memory to be executedexecuted

ProblemsProblems– Programs compete for spacePrograms compete for space– May have a very large programMay have a very large program– Memory space for each program must not Memory space for each program must not

overlapoverlap

Memory ManagementMemory Management

The process of providing separate The process of providing separate memory space to programsmemory space to programs

Memory Protection keeps one Memory Protection keeps one program from interfering with anotherprogram from interfering with another

Sharing StorageSharing Storage

Several users need to access the same Several users need to access the same disk packdisk pack– One wants to writeOne wants to write– Another wants to readAnother wants to read

OS keeps track of the I/O requestsOS keeps track of the I/O requests

OS processes I/O requests in order OS processes I/O requests in order receivedreceived

Utility ProgramsUtility Programs

Come with System SoftwareCome with System Software Handle special needsHandle special needs Perform secondary choresPerform secondary chores Do not need to be memory residentDo not need to be memory resident

Functions of Utility programsFunctions of Utility programs

File managerFile manager – provide access to lists of stored files – provide access to lists of stored files Backup and Restore – make duplicate copies of Backup and Restore – make duplicate copies of

important files and return the copy to the hard drive if important files and return the copy to the hard drive if neededneeded

File compressionFile compression – reduces the amount of disk – reduces the amount of disk space required by a filespace required by a file

Disk defragmenterDisk defragmenter – reorganize files so they are – reorganize files so they are stored contiguously on disk providing for faster stored contiguously on disk providing for faster accessaccess

Device driversDevice drivers – convert operating system – convert operating system instructions into commands that are known to a instructions into commands that are known to a specific devicespecific device

Are all operating systems the same?

Features and functions.Features and functions.

Advantages and benefits.Advantages and benefits.

From Personal Computers to Mainframes?

Summary

Operating systems are the foundation of a computer operation.

Operating systems benefits include better resource utilization, better system performance, gains in cost-effectiveness and better overall management of the entire system.

Without operating systems with advanced features and functions, computing would still be in its very early stages.