1. Chapter 06: System Software

2. Definition  Master program  Controls all hardwares connected to computer  Collection of programs Users Application software Operating System/ system software Hardware

3. System Software/Operating Systems

4. Operating Systems  A collection of programs that handle technical tasks, including managing computer resources  Every computer has an operating system (OS), such as Windows 7 or Mac OS X  The OS provides the interface between the user and computer, and is required to run applications

5. Functions of an Operating System  Manages computer resources  Coordinate memory, processing storage, and printers  Monitor system performance  Provide security  Start-up the computer  Provides user interface  Character-based interface  Graphical user interface (GUI)  Runs applications  Multitasking  Foreground and background applications

6. Program Interface Humans User Programs O.S. Interface O.S. Hardware Interface/ Privileged Instructions Disk/Tape/Memory The Layers Of A System System

7. Layers of System Software

8. Booting  Booting is the process of bringing OS from Hard disk to RAM

9. Categories of Operating Systems  Hundreds of operating systems  Three basic categories  Embedded operating systems (handheld)  Network operating systems (linked computers)  Stand-alone operating systems (desktop)

10. Storage Hierarchy Very fast storage is very expensive. So the Operating System manages a hierarchy of storage devices in order to make the best use of resources. In fact, considerable effort goes into this support. 1: Operating Systems Overview10 Fast and Expensive Slow an Cheap

11. Operating System - Properties 1. Batch processing Mr. Mohamm ed Rahmath

12. Operating System - Properties 2. Multitasking Mr. Mohamm ed Rahmath

13. Operating System - Properties 3. Multiprogramming Mr. Mohamm ed Rahmath