OPERATING SYSTEMS

T S Pradeep KumarVITCC

http://www.pradeepkumar.orgLecture 1

OVERVIEW

What is an Operating System History of Operating system Modern OS Functionality Recent Developments in OS

WHAT IS AN OPERATING SYSTEM

USER Hardware

Interacts

SERVICES

OSservic

es

Tasks

CPU Schedulin

g

MemoryNetworking

File System

COORDINATION

Coordinates multiple applications and processes in a fair manner

GOAL

The goal in OS development is to makethe machine convenient to use (asoftware engineering problem) andefficient (a system engineeringproblem)

FINALLY….

ILLUSIONAL FEELING TO AN USERPROVIDES A SERVICE EVERYONE NEEDS

FINALLY….

ALWAYS THERE WHEN YOU NEED, NEVER BREAKS

ALLOCATES RESOURCES EFFECTIVELY AND PROVIDES SAFETY AND SECURITY

FINALLY….

A complex System but keep it as simple as possible so that It will work

HISTORY

Phase 0 – Hardware is very expensive, no OS exists One User console Uses Card Deck to load programs

HISTORY

Phase 1 – Hardware is expensive, humans are cheap Simple batch processing: load program, run, print

results, dump, repeat Overlapped CPU and IO Operations Multiprogrammed Batch Systems

Phase 2 – Hardware is less expensive than before, still humans are expensive Interactive timesharing Unix

HISTORY

Phase 3 – Hardware is very cheap, humans are cheap Personal Computing

RECENT DEVELOPMENTS

Parallel Operating Systems Shared memory and clock, more tightly

coupled systems Distributed OS

No shared memory or clock, less no of loosely coupled systems

Real Time OS (RTOS) Meeting deadline constraints

RECENT DEVELOPMENTS

Mobile OS Symbian, Meego, Android, iOS…..

Surface OS Click this to see a video

QUESTIONS???