1 Chapter 2 Operating Systems: Software in the Background

2/26 What is an Operating System? Set of programs between application software and hardware

3/26 Operating System Definitions Kernel – main program Booting

4/26 Functions of an Operating System Manage computer’s resources User interface Services for application software

5/26 Basics of a Personal Computer Operating System Platform Operating system Hardware Application software is platform specific

6/26 Comparing User Interfaces Command line Text based User must memorize commands Graphical user interface Icons Mouse Nothing to memorize

7/26 Home/Consumer Market Windows 95 and Windows 98 Plug and Play Object Linking and Embedding (OLE) Long file names Internet browsing DVD Wizards Utilities

8/26 Home/Consumer Market Windows Me More multimedia support Restores system files Automatic updates Home network wizard

9/26 Corporate Market Windows NT Network environment Stronger security features NT workstation and NT server

10/26 Corporate Market Windows 2000 Windows NT and Windows 98 Personalized preferences Windows 2000 Professional and Windows 2000 Server

11/26 Windows XP Extends Windows Me More stable environment Network Server Desktop Computer Professional Client Personal Client

12/26 Windows CE Subset of Windows Embedded Systems Pocket computers Internet connectivity

13/26 Other Operating Systems Mac OS UNIX LINUX

14/26 Network Operating Systems Sharing of resources Data security Troubleshooting Administrative control

15/26 Operating Systems for Large Computers Mainframes Used by many people at once Several programs in memory Special problems

16/26 Sharing the CPU Multiprocessing Multiple CPUs Each CPU with one program Programs run simultaneously

17/26 Sharing the CPU Multiprogramming Multiple programs Programs run concurrently Event-driven Interrupts

18/26 Sharing the CPU Time-sharing Multiple users Time-driven Time slice

19/26 Memory management Partitions or regions Foreground Background

20/26 Memory Management Virtual storage Paging Page table Thrashing Memory protection

21/26 Resource Allocation Sharing storage resources Sharing printing resources Spooling

22/26 Utility programs File manager allows you to view directories allows copy, move, rename, delete, etc. Windows Explorer

23/26 Utility programs Device drivers Backup and restore File compression WinZip

24/26 Utility programs Defragmenter