Introduction to OS Introduction to OS & &

Computer organizationComputer organization

© Dr. Aiman Hanna© Dr. Aiman HannaDepartment of Computer Science Department of Computer Science

Concordia University Concordia University Montreal, CanadaMontreal, Canada

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Introduction to OSIntroduction to OS

What is an OS?What is an OS?

Software:Software:System softwareSystem softwareApplication softwareApplication software

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ApplicationSoftware

SystemSoftware

Hardware

(a) End UserView

(b) ApplicationProgrammer

View

(c) OS ProgrammerView

ApplicationSoftware

ApplicationSoftware

SystemSoftware

SystemSoftware

Hardware Hardware

cutsave

printsend

malloc()fork()

open()read-disk

track-mouse

start-printer

Software/HardwareSoftware/Hardware

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Different Software/Hardware Different Software/Hardware InterfacesInterfaces

Hardware Resources

Trusted OS

(Abstract Resources)

Software-Hardware Interface

OS Interface

System Software

(More Abstract Resources)

API

Application Software

Human-Computer Interface

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Introduction to OSIntroduction to OS

Different Kinds of OSDifferent Kinds of OSBatchBatchTimesharingTimesharingReal-timeReal-timeDedicated (Embedded)Dedicated (Embedded)……etc.etc.

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Basic Functions of OSBasic Functions of OS

Resource AbstractionResource Abstraction

Resource SharingResource Sharing

Resource Isolation Resource Isolation

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Advantages of SharingAdvantages of Sharing

MultiprogrammingMultiprogramming

MultitaskingMultitasking

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Computer OrganizationComputer Organization

Von Neumann Architecture Von Neumann Architecture ALUALUControl UnitControl UnitI/O DevicesI/O Devices……..

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Memory OrganizationMemory Organization

IR, MDR, PC, …IR, MDR, PC, …

Fetch cycleFetch cycle

Interrupt cycleInterrupt cycle

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Where is this week coverage in Where is this week coverage in the textbook?the textbook?

Chapter 1:Chapter 1:All chapter with the following exceptionsAll chapter with the following exceptions Skip: Skip: VxWorks (page 33), Windows CE (page 36)VxWorks (page 33), Windows CE (page 36)

Chapter 2:Chapter 2:All chapter with the following exceptionsAll chapter with the following exceptionsSkip: Skip: Using Files (page 48 until page 52), Using Using Files (page 48 until page 52), Using

FORK/JOIN & QUIT (page 55 until the end of this FORK/JOIN & QUIT (page 55 until the end of this chapter, including Lab Exercise (page 76))chapter, including Lab Exercise (page 76))

Note: Parts of this skipped sections may be allocated to the labNote: Parts of this skipped sections may be allocated to the lab

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Where is this week coverage in Where is this week coverage in the textbook?the textbook?

Chapter 4:Chapter 4:Sections 4.1, 4.2 & 4.3Sections 4.1, 4.2 & 4.3 Nothing to be skipped from these sectionsNothing to be skipped from these sections Other parts of chapter 4 is covered in week 2Other parts of chapter 4 is covered in week 2