IT 10103 IT 10103 Introduction to Information TechnologyIntroduction to Information Technology

CHAPTER 08 – Operating SystemCHAPTER 08 – Operating System

System SoftwareSystem Software

System Software?System Software?Programs that control or maintain the Programs that control or maintain the

operations of the computer and its devices.operations of the computer and its devices.The interface between the user, application The interface between the user, application

software, and the computer’s hardware.software, and the computer’s hardware.

System SoftwareSystem Software

Two Types of System SoftwareTwo Types of System Software

Operating SystemsOperating SystemsUtility ProgramsUtility Programs

System SoftwareSystem Software

Operating System SoftwareOperating System SoftwareCoordinates all the activity of the computer Coordinates all the activity of the computer

hardwarehardware

System SoftwareSystem Software

Operating System SoftwareOperating System SoftwareResides on the Hard Drive usually found on Resides on the Hard Drive usually found on

the 1the 1stst Hard Drive Partition or Drive C:\ Hard Drive Partition or Drive C:\

System SoftwareSystem SoftwareOperating System FunctionsOperating System Functions

Starting A ComputerStarting A ComputerProviding a User InterfaceProviding a User Interface

Managing ProgramsManaging ProgramsManaging MemoryManaging MemoryScheduling JobsScheduling Jobs

Configuring DevicesConfiguring DevicesEstablishing Network ConnectionsEstablishing Network Connections

Monitoring PerformanceMonitoring PerformanceFile ManagementFile Management

Controlling a NetworkControlling a NetworkAdministering SecurityAdministering Security

System SoftwareSystem SoftwareStarting A ComputerStarting A Computer

Booting a ComputerBooting a ComputerCold Boot – Turning on the computerCold Boot – Turning on the computerWarm Boot – Restarting the computerWarm Boot – Restarting the computer

System SoftwareSystem Software

How does a personal computer boot up?How does a personal computer boot up?Step 1. Power supply sends signal to com-ponents in system unit

Step 4. Results of POST are compared with data in CMOS chip

Step 2. Processor accesses BIOS to start computer

Step 3. BIOS runs tests, called the POST, to check components such as mouse, keyboard, and adapter cards

Step 5. BIOS looks for system files in floppy disk drive or CD/DVD drive, and then hard disk

Step 6. Kernel (core) of operating system loads into RAM

Step 7. Operating system loads configuration information and displays desktop on screen

System SoftwareSystem SoftwareProviding a User InterfaceProviding a User Interface

Controls how data is entered and how Controls how data is entered and how information is displayedinformation is displayed

Three Types:Three Types:Command-Line InterfaceCommand-Line Interface

Menu-Driven InterfaceMenu-Driven InterfaceGraphical User Interface (GUI)Graphical User Interface (GUI)

System SoftwareSystem SoftwareCommand-Line InterfaceCommand-Line Interface

System SoftwareSystem SoftwareMenu-Driven InterfaceMenu-Driven Interface

System SoftwareSystem SoftwareGraphical User Interface (GUI)Graphical User Interface (GUI)

System SoftwareSystem SoftwareManaging ProgramsManaging Programs

There are four ways an OS manages There are four ways an OS manages programs:programs:

System SoftwareSystem SoftwareReal-time operating systemReal-time operating system (RTOS) (RTOS)

Real-time operating systems are used to control Real-time operating systems are used to control machinery, scientific instruments and industrial systems. machinery, scientific instruments and industrial systems.

An RTOS typically has very little user-interface An RTOS typically has very little user-interface capability, and no end-user utilities, since the system will capability, and no end-user utilities, since the system will

be a "sealed box" when delivered for use. A very be a "sealed box" when delivered for use. A very important part of an RTOS is managing the resources of important part of an RTOS is managing the resources of the computer so that a particular operation executes in the computer so that a particular operation executes in precisely the same amount of time every time it occurs. precisely the same amount of time every time it occurs. In a complex machine, having a part move more quickly In a complex machine, having a part move more quickly just because system resources are available may be just just because system resources are available may be just as catastrophic as having it not move at all because the as catastrophic as having it not move at all because the

system is busy. system is busy.

System SoftwareSystem SoftwareSingle-user, single taskSingle-user, single task

As the name implies, this operating system is As the name implies, this operating system is designed to manage the computer so that one designed to manage the computer so that one user can effectively do one thing at a time. The user can effectively do one thing at a time. The

Palm OSPalm OS for Palm handheld computers is a good for Palm handheld computers is a good example of a modern single-user, single-task example of a modern single-user, single-task

operating system. operating system.

System SoftwareSystem SoftwareSingle-user, multi-taskingSingle-user, multi-tasking

This is the type of operating system most people This is the type of operating system most people use on their desktop and laptop computers today. use on their desktop and laptop computers today.

Microsoft's Microsoft's WindowsWindows and Apple's and Apple's MacOSMacOS platforms are both examples of operating platforms are both examples of operating

systems that will let a single user have several systems that will let a single user have several programs in operation at the same time. For programs in operation at the same time. For

example, it's entirely possible for a Windows user example, it's entirely possible for a Windows user to be writing a note in a word processor while to be writing a note in a word processor while

downloading a file from the Internet while printing downloading a file from the Internet while printing the text of an e-mail message. the text of an e-mail message.

System SoftwareSystem SoftwareMulti-userMulti-user

A multi-user operating system allows many A multi-user operating system allows many different users to take advantage of the different users to take advantage of the

computer's resources simultaneously. The computer's resources simultaneously. The operating system must make sure that the operating system must make sure that the

requirements of the various users are balanced, requirements of the various users are balanced, and that each of the programs they are using has and that each of the programs they are using has

sufficient and separate resources so that a sufficient and separate resources so that a problem with one user doesn't affect the entire problem with one user doesn't affect the entire community of users. Unix, VMS and mainframe community of users. Unix, VMS and mainframe operating systems, such as operating systems, such as MVSMVS, are examples , are examples

of multi-user operating systems of multi-user operating systems

System SoftwareSystem SoftwareMulti-ProcessingMulti-Processing

Supports two or more processors (CPU)Supports two or more processors (CPU)

Aysmmetric: one CPU does the work of the system, the other

CPUs service user requests.

Symmetric: All processors can be

used by the system and users alike. No CPU is

special.

System SoftwareSystem SoftwareManaging MemoryManaging Memory

To optimize the use of random access To optimize the use of random access memory or RAM. One way to do this is to memory or RAM. One way to do this is to

utilize Virtual Memoryutilize Virtual Memory

System SoftwareSystem SoftwareVirtual MemoryVirtual Memory

The OS allocates a portion of storage (usually The OS allocates a portion of storage (usually the hard drive) to function as additional RAM.the hard drive) to function as additional RAM.

System SoftwareSystem SoftwareVirtual MemoryVirtual Memory

The OS allocates a portion of storage (usually The OS allocates a portion of storage (usually the hard drive) to function as additional RAM.the hard drive) to function as additional RAM.

Step 1. The operating system transfers the least recently used data and program instructions to disk because memory is needed for other functions.

Step 2. The operating system transfers data and program instructions from disk to memory when they are needed.

System SoftwareSystem SoftwareWindows Vista ReadyBoostWindows Vista ReadyBoost

Windows ReadyBoost lets users use a Windows ReadyBoost lets users use a removable flash memory device, such as a removable flash memory device, such as a

USB thumb drive, to improve system USB thumb drive, to improve system performance without opening the box. performance without opening the box.

Windows ReadyBoost can improve system Windows ReadyBoost can improve system performance because it can retrieve data kept performance because it can retrieve data kept on the flash memory more quickly than it can on the flash memory more quickly than it can

retrieve data kept on the hard disk, retrieve data kept on the hard disk, decreasing the time you need to wait for your decreasing the time you need to wait for your

PC to respond.PC to respond.

System SoftwareSystem SoftwareWindows Vista ReadyBoostWindows Vista ReadyBoost

ReadyBoost does ReadyBoost does notnot cache file writes—it's a cache file writes—it's a write-through cache. That way, you never lose write-through cache. That way, you never lose

any precious data that's meant to be written to a any precious data that's meant to be written to a hard drive. After all, a flash memory key can get hard drive. After all, a flash memory key can get yanked out of a system at any time. The cache yanked out of a system at any time. The cache itself is encrypted using AES-128 encryption, so itself is encrypted using AES-128 encryption, so

no one can steal your flash memory key and no one can steal your flash memory key and casually browse through the cache file to see casually browse through the cache file to see

what you've been doing. what you've been doing.

System SoftwareSystem SoftwareScheduling JobsScheduling Jobs

Determines the order in which jobs are Determines the order in which jobs are processed. A job is an operation the processed. A job is an operation the

processor manages.processor manages.Utilizes a BufferUtilizes a Buffer – a segment of memory for – a segment of memory for

temporary storage of items until neededtemporary storage of items until neededUtilizes SpoolingUtilizes Spooling – sending a job to a buffer – sending a job to a buffer

instead of directly to a device (printers)instead of directly to a device (printers)Utilizes a QueueUtilizes a Queue – a list in the buffer of jobs – a list in the buffer of jobs

waiting to be completedwaiting to be completed

System SoftwareSystem SoftwareConfiguring DevicesConfiguring Devices

The OS configures through a Device Driver or The OS configures through a Device Driver or Driver. Each hardware component of a Driver. Each hardware component of a

computer has a device driver. It is how the computer has a device driver. It is how the OS communicates with the hardware.OS communicates with the hardware.

Plug-N-Play – the OS automatically configures Plug-N-Play – the OS automatically configures any new devices connected to the computerany new devices connected to the computer

System SoftwareSystem SoftwareEstablishing a Network ConnectionEstablishing a Network Connection

Provides the means of making a connection Provides the means of making a connection to a network including the Internetto a network including the Internet

Usually a Web Browser is provided for the Usually a Web Browser is provided for the Internet connection functionInternet connection function

System SoftwareSystem SoftwareMonitoring PerformanceMonitoring Performance

A part of the OS that shows the performance A part of the OS that shows the performance statistics of the system. Useful for statistics of the system. Useful for

troubleshooting problems or just seeing how troubleshooting problems or just seeing how well your system works.well your system works.

(In Windows XP it is located under the (In Windows XP it is located under the Task Manager Dialog Box)Task Manager Dialog Box)

System SoftwareSystem SoftwareFile ManagementFile Management

Saving, Reading, Copying, Moving, DeletingSaving, Reading, Copying, Moving, DeletingWindows Explorer is the primary file manager Windows Explorer is the primary file manager

in Windows XPin Windows XP

System SoftwareSystem SoftwareControlling a NetworkControlling a Network

Some Operating Systems are specifically Some Operating Systems are specifically designed to control networks. These types designed to control networks. These types

are called Network Operating Systems (NOS).are called Network Operating Systems (NOS).They coordinate the activities of the networkThey coordinate the activities of the network

System SoftwareSystem SoftwareAdministering SecurityAdministering Security

The OS provides a way to control user access The OS provides a way to control user access through security authentication. through security authentication.

Example: Logging into this labs computersExample: Logging into this labs computers

System SoftwareSystem SoftwareSystem UtilitiesSystem Utilities

A program that allows us to perform A program that allows us to perform maintenance or management of our maintenance or management of our

computers. These include File Managers, computers. These include File Managers, Image Viewers, Uninstallers, Disk Scanners, Image Viewers, Uninstallers, Disk Scanners, Disk Defragmenters, Diagnostics, Backup, Disk Defragmenters, Diagnostics, Backup,

Screen Savers, Spyware/Adware Removers, Screen Savers, Spyware/Adware Removers, and Antivirus Utilities.and Antivirus Utilities.

System SoftwareSystem SoftwareStand-Alone Operating SystemsStand-Alone Operating Systems

DOSDOSWINDOWSWINDOWSMAC OS XMAC OS X

UNIXUNIXLINUXLINUX

System SoftwareSystem SoftwareNetwork Operating SystemNetwork Operating System

NETWARENETWAREWINDOWS SERVERWINDOWS SERVER

UNIXUNIXLINUXLINUX

SOLARISSOLARIS

System SoftwareSystem SoftwareEmbedded Operating SystemEmbedded Operating System

WINDOWS CEWINDOWS CEWINDOWS MOBILEWINDOWS MOBILE

PALM OSPALM OSSYMBIAN OSSYMBIAN OS

System SoftwareSystem SoftwareTypes of Utility SoftwareTypes of Utility Software

Antivirus ProgramsAntivirus ProgramsPersonal FirewallsPersonal FirewallsFile CompressionFile Compression

Personal Computer MaintenancePersonal Computer Maintenance

System SoftwareSystem SoftwarePersonal FirewallPersonal Firewall

System SoftwareSystem SoftwareQUESTIONS ?QUESTIONS ?

System SoftwareSystem SoftwareBUYERS GUIDE 2006BUYERS GUIDE 2006

PAGE 444PAGE 444

System SoftwareSystem SoftwareASSIGNMENT 06ASSIGNMENT 06

Buy a New PC Computer (Pretend)Buy a New PC Computer (Pretend)You can choose whatever components you You can choose whatever components you

want from any supplier or retailer.want from any supplier or retailer.Explain to me why you chose this computer Explain to me why you chose this computer

and what it will do for you. Also list the and what it will do for you. Also list the individual components of the computer and individual components of the computer and

the final total cost of the system. the final total cost of the system. You have a budget of: $ 5,000.00You have a budget of: $ 5,000.00

System SoftwareSystem SoftwareSome Starting Points:Some Starting Points:

System ResellersSystem Resellerswww.dell.comwww.dell.com

www.gateway.comwww.gateway.comwww.hp.comwww.hp.com

Parts ResellersParts Resellerswww.newegg.comwww.newegg.comwww.mwave.comwww.mwave.com

www.buy.comwww.buy.comwww.pricewatch.comwww.pricewatch.com