Download Introduction to Operating Systems

Operating Systems
Introduction to Operating Systems
Prepared by: Dhason
Topic & Structure of the lesson
Introduction to Operating Systems
• Basic functions of operating systems
Operating Systems
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Learning Outcomes
Introduction to Operating Systems
• At the end of this lecture YOU should be able to:
- Discuss the functions of operating systems
Operating Systems
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Introduction
Introduction to Operating Systems
• A computer system consists of :
- users, application programs, operating
systems and hardware
• An operating system is the layer of software that
manages all parts of the hardware and presents an
interface that is easier to understand
• An operating system shields programmers from
hardware complexity
Operating Systems
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Introduction (cont.)
Introduction to Operating Systems
• An operating system can be defined as :
- a program that acts as an intermediary
between a computer user and the computer
hardware
- a resource allocator
- a resource manager
- a control program
Operating Systems
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Basic Functions of an Operating System
Introduction to Operating Systems
• Accepts commands from the user
• Provides desired services to the user and user programs
• Act as a system manager / resource manager
- controls hardware and software
- act as an interface between user and system
• Manages resources of the computer effectively
Operating Systems
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Services of an Operating System
Introduction to Operating Systems
A. Services provided to users and programs:
Program Execution – loads a program in memory, runs
and terminates the execution either normally or
abnormally
Input-Output Operations – control input-output devices
File System Manipulation – allow reading, writing,
deletion, creating of files
Operating Systems
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Services of an Operating System (cont.)
Introduction to Operating Systems
Communication – manage shared memory or
message passing for the exchange of
information between processes
Error Detection – take measures to correct errors
to ensure a consistent state
Operating Systems
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Services of an Operating System (cont.)
Introduction to Operating Systems
B. Services to ensure efficient operation of the operating
system:
Resource allocation – CPU scheduling routines for
memory, input output devices, file storage to decide the
best method to utilize the CPU
Accounting – which users are using what kind and how
much resources. Usage statistics for performance
improvement
Protection – user, process and data protection
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Quick Review Questions
Introduction to Operating Systems
1) State and explain one function of operating systems
Operating Systems
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Question and Answer Session
Introduction to Operating Systems
Q&A
Operating Systems
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