1. OPERATING SYSTEMS
T S Pradeep Kumar
VITCC
http://www.pradeepkumar.org
Lecture 1

2. OVERVIEW
 What is an Operating System
 History of Operating system
 Modern OS Functionality
 Recent Developments in OS

3. WHAT IS AN OPERATING SYSTEM
Interacts
USER
Hardware

4. SERVICES
Tasks
CPU
File System
Scheduling
OS
services
Networking Memory

5. COORDINATION
Coordinates
multiple
applications and
processes in a fair
manner

6. GOAL
The goal in OS
development is to
make
the machine
convenient to use
(a
software engineering
problem) and
efficient (a system
engineering
problem)

7. ILLUSIONAL FEELING TO AN USER PROVIDES A SERVICE EVERYONE NEEDS
FINALLY….

8. ALWAYS THERE WHEN YOU NEED, NEVER ALLOCATES RESOURCES EFFECTIVELY
BREAKS AND PROVIDES SAFETY AND SECURITY
FINALLY….

9. A complex
System but
keep it as
simple as
possible so
that It will
work
FINALLY….

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

11. 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

12. HISTORY
 Phase 3 – Hardware is very cheap, humans
are cheap
 Personal Computing

13. 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

14. RECENT DEVELOPMENTS
 Mobile OS
 Symbian, Meego, Android, iOS…..
 Surface OS
 Click this to see a video

18. QUESTIONS???