1. Introduction to OS & Computer organization © Prof. Aiman Hanna Department of Computer Science Concordia University Montreal, Canada

2. 2 Introduction to OS What is an OS? What is an OS? Software: Software: System software System software Application software Application software

3. 3 Application Software System Software Hardware (a)End User View (b) Application Programmer View (c) OS Programmer View Application Software Application Software System Software System Software Hardware cut save print send malloc() fork() open() read-disk track-mouse start-printer Software/Hardware

4. 4 Different Software/Hardware Interfaces Hardware Resources Trusted OS (Abstract Resources ) Software-Hardware Interface OS Interface System Software (More Abstract Resources ) API Application Software Human-Computer Interface

5. 5 Introduction to OS Different Kinds of OS Different Kinds of OS Batch Batch Timesharing Timesharing Real-time Real-time Dedicated (Embedded) Dedicated (Embedded) …etc. …etc.

6. 6 Basic Functions of OS Resource Abstraction Resource Abstraction Resource Sharing Resource Sharing Resource Isolation Resource Isolation

7. 7 Advantages of Sharing Multiprogramming Multiprogramming Multitasking Multitasking

8. 8 Computer Organization Von Neumann Architecture Von Neumann Architecture ALU ALU Control Unit Control Unit I/O Devices I/O Devices …. ….

9. 9 Memory Organization IR, MDR, PC, … IR, MDR, PC, … Fetch cycle Fetch cycle Interrupt cycle Interrupt cycle

10. 10 Where is this week coverage in the textbook? Chapter 1: Chapter 1: All chapter with the following exceptions All chapter with the following exceptions  Skip: VxWorks (page 33), Windows CE (page 36) Chapter 2: Chapter 2: All chapter with the following exceptions All chapter with the following exceptions  Skip: Using Files (page 48 until page 52), Using FORK/JOIN & QUIT (page 55 until the end of this chapter, including Lab Exercise (page 76))  Note: Parts of this skipped sections may be allocated to the lab

11. 11 Where is this week coverage in the textbook? Chapter 4: Chapter 4: Sections 4.1, 4.2 & 4.3 Sections 4.1, 4.2 & 4.3  Nothing to be skipped from these sections  Other parts of chapter 4 is covered in week 2