Introduction to OS Computer organization Dr Aiman Hanna

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

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

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

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

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

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

Advantages of Sharing l Multiprogramming l Multitasking 7

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

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

Where is this week coverage in the textbook? l Chapter 1: l All chapter with the following exceptions Skip: Vx. Works (page 33), Windows CE (page 36) l Chapter 2: l 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 10

Where is this week coverage in the textbook? l Chapter 4: l Sections 4. 1, 4. 2 & 4. 3 Nothing to be skipped from these sections Other parts of chapter 4 is covered in week 2 11