Operating System – An Introduction : Operating System – An Introduction V. Vasantha M.E.,
Senior Lecturer,
Dept. Of Information Technology,
National Engineering College,
K. R. Nagar, Kovilpatti.
vasantha14@yahoo.com
Operating System - Definition : Operating System - Definition Operating System (or shortly OS) primarily provides services for running applications on a computer system. 9/23/2010 2 SPOS Unit I Vasantha Vivek
Operating System Functionality : Operating System Functionality 9/23/2010 3 SPOS Unit I Vasantha Vivek
OS Functions : OS Functions Resource Allocation
User Interface 9/23/2010 4 SPOS Unit I Vasantha Vivek
Resource Allocation : Resource Allocation Static Allocation
Dynamic Allocation
Resource Table
Resource Sharing
Sequential Sharing
Concurrent Sharing 9/23/2010 5 SPOS Unit I Vasantha Vivek
Terms & Terminologies : Terms & Terminologies Resource Preemption
CPU Scheduling
Program
Process
Job
Batch Forceful deallocation of resources Deciding which program to get CPU & how much time Set of computations or instructions Execution of a program or a part of of program Sequence of programs Sequence of user jobs 9/23/2010 6 SPOS Unit I Vasantha Vivek
Evolution of OS : Evolution of OS 9/23/2010 7 SPOS Unit I Vasantha Vivek
Evolution of OS – Contd., : Evolution of OS – Contd., Batch Processing System
Multiprogramming System
Time Sharing System
Real Time OS ( RTOS ) 9/23/2010 8 SPOS Unit I Vasantha Vivek
OS Examples : OS Examples Desktop, server - OS-X, Windows, Linux, *BSD, ...
PDA - PalmOS Windows/CE
Cell phones - Symbian, JavaOS
Real-time - VxWorks, pSOS 9/23/2010 9 SPOS Unit I Vasantha Vivek
Exercises : Exercises Define Turn around time.
Batch procesing aims at ____________________.
FCFS scheduling is used by __________________. 9/23/2010 10 SPOS Unit I Vasantha Vivek
Match it : Match it Concurrent CPU System call
& IO Opreations
Program makes a Throughput
request to OS
N Multiprogramming
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Tf – To 9/23/2010 11 SPOS Unit I Vasantha Vivek
Find Me : Find Me N O I T P M E E R P
S I N G A P P W
M L I T S K I G U T A N
K L E N A R 9/23/2010 12 SPOS Unit I Vasantha Vivek
Slide 13 : 9/23/2010 SPOS Unit I Vasantha Vivek 13 Queries ??? http:\\wiziq.com\vasantha