Applied OS

Chapter 1: Introduction

Chapter 1: Introduction
What Operating Systems Do
Computer-System Organization
Computer-System Architecture
Operating-System Structure
Operating-System Operations
Process Management
Memory Management
Storage Management
Protection and Security
Distributed Systems
Special-Purpose Systems
Computing Environments

Operating System Concepts – 7th Edition, Jan 12, 2005

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Objectives
To provide a grand tour of the major operating systems components To provide coverage of basic computer system organization

Operating System Concepts – 7th Edition, Jan 12, 2005

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What is an Operating System?
A program that acts as an intermediary between a user of a computer and the computer hardware.
Operating system goals:
Execute user programs and make solving user problems easier. Make the computer system convenient to use.
Use the computer hardware in an efficient manner.

Operating System Concepts – 7th Edition, Jan 12, 2005

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Computer System Structure
Computer system can be divided into four components
Hardware – provides basic computing resources
CPU, memory, I/O devices
Operating system
Controls and coordinates use of hardware among various applications and users
Application programs – define the ways in which the system resources are used to solve the computing problems of the users Word processors, compilers, web browsers, database systems, video games
Users
People, machines, other computers

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Silberschatz, Galvin and Gagne ©2005

Four Components of a Computer System

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Silberschatz, Galvin and Gagne ©2005

Operating System Definition
OS is a resource allocator
Manages all resources
Decides between conflicting requests for efficient