7A-*Functions of Operating SystemsProvide a user interfaceRun programsManage hardware devicesOrganized file storage

Types of Operating SystemsReal-time operating systemVery fast small OSBuilt into a deviceRespond quickly to user inputMP3 players, Medical devices

Types of Operating SystemsSingle user/Single tasking OSOne user works on the systemPerforms one task at a timeMS-DOS and Palm OSTake up little space on diskRun on inexpensive computers

Types of Operating SystemsSingle user/Multitasking OSUser performs many tasks at onceMost common form of OSWindows XP and OS XRequire expensive computersTend to be complex

Types of Operating SystemsMulti user/Multitasking OSMany users connect to one computerEach user has a unique sessionUNIX, Linux, and VMSMaintenance can be easyRequires a powerful computer

Multi user/Multi tasking OS

Providing a User InterfaceGraphical user interface (GUI)Most common interfaceWindows, OS X, GnomeUses a mouse to control objectsUses a desktop metaphorShortcuts open programs or documentsOpen documents have additional objectsTask switchingDialog boxes allow directed input

Graphical User Interface

Providing a User InterfaceCommand line interfacesOlder interfaceDOS, Linux, UNIXUser types commands at a promptUser must remember all commandsIncluded in all GUIs

Command Line Interface

Managing HardwarePrograms need to access hardwareInterruptsCPU is stoppedHardware device is accessedDevice drivers control the hardware

Organizing Files and FoldersOrganized storageLong file namesFolders can be created and nestedAll storage devices work consistently

Enhancing an OSUtilitiesProvide services not included with OSGoes beyond the four functionsFirewall, anti-virus and compressionPrices vary

Copyright 2006 by The McGraw-Hill Companies, Inc. All rights reserved.McGraw-Hill Technology Education

Chapter 7AEnd of Chapter

*Teaching TipFile and folder storage is covered in chapter 6. *Teaching tipIt is true that multi-tasking operating systems are complex. However both XP and OS X make the multitasking process painless for the user. *Teaching tipMulti-user Multitasking OS's are found on supercomputers, mainframes and minicomputers. Through Linux, a PC can also support user sessions and terminal connections. *Insider informationThe first commercial GUI was the Xerox Star.

Teaching TipThere are several types of dialog boxes. Any errors are displayed in a dialog box. This box is system modal - it requires a response before returning to the OS. Save and print boxes are application modal - The box must be dealt with before returning to the application. However, other OS tasks can be performed.*Teaching tipDemonstrate the command line interface in Windows by running cmd. In the command line interface use ping and ipconfig as commands that cannot be run in the GUI. *Discussion pointThe mouse uses an interrupt. Many users will move the mouse while waiting for the CPU to finish a task. What does moving the mouse do to the current process?

Teaching tipDiscuss what can happen when the wrong driver is installed on a computer. *Discussion pointWith Windows XP and SP2, Microsoft has included a firewall and pop-up blocker both typically considered utility software. In the near future, the core services provided by an OS may include security features.