Operating System

1. Chapter (2)
Operating System Overview
Dr. Hnin Lai Nyo
Lecturer
Faculty of Computer Science

2. Lecture Contents
 Lecture 1: Operating System Objectives and Functions
 Lecture 2: The Evolution of Operating System
 Lecture 3: Major Achievements
 Lecture 4: Developments Leading to Modern Operating Systems
 Lecture 5: Virtual Machines
 Lecture 6: OS Design Considerations for Multiprocessor and Multicore
FACULTY OF COMPUTER SCIENCE, UNIVERSITY OF COMPUTER STUDIES

3. Lecture 1: Operating System Objectives and Functions
FACULTY OF COMPUTER SCIENCE, UNIVERSITY OF COMPUTER STUDIES
 What is Operating System?
 Operating System Objectives
 Operating System Functions
 Operating System Services
 Key Interfaces

4. Learning Objectives
FACULTY OF COMPUTER SCIENCE, UNIVERSITY OF COMPUTER STUDIES
 To introduce the basic elements of computer system and their relationships
 To understandd the key function of an operating system
 To know the operating system services

5. FACULTY OF COMPUTER SCIENCE, UNIVERSITY OF COMPUTER STUDIES
 A program that controls the execution application programs
 An interface between applications and hardware
What is Operating System?

6. FACULTY OF COMPUTER SCIENCE, UNIVERSITY OF COMPUTER STUDIES
What is Programming Language ?
Operating System Objectives
Ability to
evolve
An OS should be constructed in such a way as to permit the
effective development, testing and introdiction of new system
functions without interfering with service
Efficiency
An OS allows the computer system resources to
be used in an efficient manner.
Convenience An OS makes a computer more convenient to use

7. FACULTY OF COMPUTER SCIENCE, UNIVERSITY OF COMPUTER STUDIES
Operating System Functions
 The Operating System as a User/Computer Interface
Application programs
Libraries/utilities
Operating System
Execution hardwre
Memory
translation
System interconnect
(bus)
I/O devices
and
networking
Main
memory
Application
programming interface
Application
binary interface
Instruction set
architecture
Software
Hardware
Figure 2.1 Computer Hardware
and Software Structure

8. FACULTY OF COMPUTER SCIENCE, UNIVERSITY OF COMPUTER STUDIES
Operating System Functions
.
.
.
Memory
Operating
system
software
Programs
and data
Processor Processor
I/O controller
I/O controller
I/O controller
.
.
.
OS
Programs
Data
Storage
.
.
.
Printers,
keyboards,
digital camera,
etc.
Computer System
I/O devices
Figure 2.2 The Operating Ssystem
as Resource Manager
 The Operating System as Resource Manager

9. FACULTY OF COMPUTER SCIENCE, UNIVERSITY OF COMPUTER STUDIES
What is Programming Language ?
Operating System Services
 Program development
 Program execution
 Access to I/O devices
 Controlled access to files
 System access
 Error detection and response
 Accounting

10. FACULTY OF COMPUTER SCIENCE, UNIVERSITY OF COMPUTER STUDIES
Key Interfaces
 Instruction set Architecture (ISA)
 Application binary interface (ABI)
 Application programming interface (API)

11. FACULTY OF COMPUTER SCIENCE, UNIVERSITY OF COMPUTER STUDIES
Summary
In this lecture, you learned about
 Operating system and its objectives
 The OS as a user computer interface and as a reosurce manager
 Services of Operating system

12. Learning Outcomes
FACULTY OF COMPUTER SCIENCE, UNIVERSITY OF COMPUTER STUDIES
After the end of the lecture, the students will be able to:
 know three objectives of an OS design
 Understand the services and functions of an operating system

13. References
FACULTY OF COMPUTER SCIENCE, UNIVERSITY OF COMPUTER STUDIES
1. “Operating Systems, internal and Design Principles” by William
Stallings, 7th Edition, ISBN 13: 978-13-230998-1.