Chapter 8

Operating Systems and Utility Programs

Serena Oldhouser

System Software

System software consists of the programs that control or maintain the operations of the computer and its devices.

Serves as an interface between user, application software, and computer hardware.

Two Types of System Software

Operating SystemsSet of programs containing instructions that coordinate

all the activities among computer hardware resources.Stored on hard drive

Utility Programs Performs maintenance tasks

Operating System

Different sizes of computer use different operating systems

Operating system is sometimes called the platform

Functions of an Operating System Starting the Computer Recovery Disk User Interface Managing Programs Managing Memory Scheduling Jobs Configuring Devices Establishing an Internet

Connection Monitoring Performance Administering Security

Starting the Computer Called Booting

Cold boot- Turning on a computer that has been powered off completely

Warm boot- Restarting a computer that already is powered on

Kernel-Core of an operating system Manages memory Starts applications Assigns the computers resources Memory resident-Remains in memory while computer is running

Recovery Disk

Special disk used to start the computer when the hard disk becomes damaged and can not boot by itself

Also called a boot diskContains a few system files that will start the

computer

Command-Line Interface A user types commands or presses special keys on

the keyboard to enter data and instructions Uses sets of commands called the command

language. Used by advanced users Difficult to use because they require exact

spelling, grammar, and punctuation Gives more control over setting details

Menu-Driven Interface

Provides menus as a means of entering commands Easier to learn

Graphical User Interface

Interact with menus and visual images such as icons, buttons, and other graphical objects to issue commands

Used by most users today Many incorporate features similar to those of a

Web browser.

User Interface

Controls how you enter data and instructions and how information is displayed on the screen.

Three types of user interfacesCommand-lineMenu-drivenGraphical

Managing Programs

Single user/single tasking operating systemAllows one user to run only one program at a time

Single user/multitasking operating systemAllows one user to run two or more programs at a time

Only one program can be in the foreground at a time, others are in the background

Managing Programs Multi-user

Enables two or more users to run programs simultaneously

Multiprocessing Supports two or more processors running programs at the same

time

Fault-tolerant computer Continues to operate when one of its components fails

Duplicate components such as processors, memory, and disk drives. Used by Airlines, communications networks & ATM’s

Managing Memory Necessary to optimize the

use of RAM May run out of RAM when

using multiple programs

Virtual memory allocates a portion of a storage medium to function as additional RAM Slower then RAM

Scheduling Jobs

Operating system determines the order in which jobs are processed Include receiving data from an input device, processing

instruction, sending information to an output device, & transferring items from storage to memory and from memory to storage

Configuring Devices

DriverSmall program that tells the operating system how to

communicate with a specific deviceLoads each time you boot the computerNeeded by the mouse, keyboard, monitor, printer, card

reader, scanner, etc.

Establishing an Internet Connection

Some systems include a web browser and e-mail program

Monitoring Performance Program that assesses and reports information

about various computer resources and devices Used to monitor

ProcessorDisksMemoryNetwork usage

Used to identify problems and resolve problems

Administering Security

Assign User ID’s or User Name Use Passwords Prevents unauthorized users from accessing

computer resources Records successful and unsuccessful logon

attempts

Operating System Utility Programs Utility Program

Allows a user to perform maintenance-type tasks

Utility Programs File manager

Formats and copies disks Displays list of files on a

storage medium Checks the amount of free

space

Image Viewer Displays and copies the

contents of a graphics file Allows the user to see the

image without opening Paint or another image editing program

Utility Programs Uninstaller

Removes programs along with any associated files

Disk Scanner Detects and corrects

physical and logical problems on the hard disk or floppy disk

Searches for and removes unnecessary files

Utility Programs Disk Defragmenter

Reorganizes the files and unused space on a computer’s hard disk

Allows the operating system to access data more quickly and programs to run faster

Reorganizes files so that they are stored in contiguous sectors

Diagnostic Utility Complies technical

information about the computer’s hardware and certain system software programs and then prepares a report outlining any identified problems

Suggests courses of action to resolve problems found

Utility Programs Backup Utility

Allows users to copy selected fields or an entire hard disk onto another disk or tape

Many compress the size of files to use less storage space

Screen Saver Displays a moving image if

there is no keyboard or mouse activity for a specified period of time

Types of Operating Systems Device –Dependant

Runs only on a specific type of computer Proprietary software

Privately owned and limited to a specific vendor or computer model

Device-Independent Run on computers provided by a variety of manufacturers Allows you to retain existing application software and data files

even if you change computer models or vendors

Three Categories of Operating Systems

Stand-aloneDOS, Windows, Mac OS X, OS/2 Warp Client, Unix,

Linux Network

Netware, Windows server, OS/2 Warp Server for e-business, UNIX, Linux, Solaris

EmbeddedWindows CD . NET, Pocket PC 2002, Palm OS,

Symbian OS

Three Categories of Operating Systems

Stand-AloneComplete operating system that works on a desktop

computer, laptop, or mobile computing deviceSometimes called, Client operating systems

Network Operating SystemDesigned specifically to support a network

Resides on a serverWork with Client operating systems

Three Categories of Operating Systems

Embedded Operating SystemsUsed in most PDA’sResides on a ROM chip

Stand-Alone Utility Programs Antivirus Programs

Protects a computer from being infected by a virus or worm or removes any that are found

Personal Firewalls Detects and Protects a

personal computer from unauthorized intrusions.

Monitor all transmissions to and from a computer

Stand-Alone Utility Programs File Compression

Shrinks the size of a file Takes up less disk space

then the original file

Personal Computer Maintenance Identifies and fixes

operating system problems Detects and repairs disk

problems