ppt slides

• 1. Operating Systems Tim Ji Lecture 1
  • Outline

• • Course Information

• • History of Operating Systems

• • Basic Components of OS

• Lab 1

• Become familiar with Linux

• Readings

• Chapter 1

2. 1 Course Information

• Official Course Outline

• • On course webpage, MS Word document

• Course Objectives/Learning Outcomes

• • Understand OS algorithms

• • Be able to write multitasking programs with a variety of inter-process communication methods

• • Be able to write scheduling, paging algorithms

• Textbook: Tanenbaum, Modern Operating Systems 2 ndEdition, Prentice Hall

3. 4. Course Information (2)

• Instructor

• • Name: Tim Ji

• • Email tji AT conestogac.on.ca

• • Office: 2A503, x2230

• • Office hour: Drop by my office or by appointment

• Grading

• • 3 tests, 20% each:60%

• • Assignments + Labs: 40%

• Assignments

• • Due in class at the end of lecture, 20% reduction in the assignment mark for each school day it is late.

• • The assignments must be your own work. Cheating/copying other peoples files will result in both papers receiving zero.

5. Course Information (3)

• Labs

• • Lab tasks will be demonstrated in the following week lab, and lab reports must be submitted by the end of the lab. You have 1 week to finish the lab task.

• Course website

• • http://www.conestogac.on.ca/~tji/os

• • Announcements, assignments, lecture handouts, etc.

• • Check it out at least once per day.

• Study to pass

• • You have to pass both the tests portion and the assignments portion

• Assignments/Labs marking

• • Demonstrate your task in lab

• • Answer questions regarding to your own task

• • Programming style of printouts of your source code, for programming assignments/labs

6. Introduction to Operating Systems

• Topics:

• • Role and purpose of the operating system

• • History of operating system development

• • Functionality of a typical operating system

• Learning Objectives:

• • Explain the objectives and functions of modern operating systems.

• • Describe how operating systems have evolved over time from primitive batch systems to sophisticated multiuser systems.

• • Describe the functions of a contemporary operating system with respect to convenience, efficiency, and the ability to evolve.

7. Early Computers

• First Computer

• • Charles Babbage (1791-1871) designed the first true digital computer called theanalytical engine .

• • That was purely mechanical and intended to do math operations

• • The engine was supposed to be made of brass, and steam powered

• • He did not actually built the machine but inspired others in the field.

8. Early Computers

• Babbage also thought of the concept ofsoftware

• And hired the first programmer (LadyAda , Countess of Lovelace) for his analytical engine

9. Current Computer Systems

• A computer system consists of

• • hardware

• • system programs

• • application programs

10. What is an Operating System (1)

• Microsoft Glossary:

• • Thesoftwarethat controls the allocation and usage of hardware resources such as memory, central processing unit (CPU) time, hard disk space, and peripheral devices (like speakers or a mouse).

• • The operating system is the foundationsoftwareon which programs, such as Word or Excel, depend.

• • An example of an operating system is Microsoft Windows XP.

11. What is an Operating System (2)

• Provide a service for clients - a virtual machine (top-down view)

• Anoperating systemis a layer of the computer system (a virtual machine) between the hardware and user programs.

• • Multiple processes

• • Multiple address spaces

• • File system

12. What is an Operating System (3)

• Resource manager (bottom-up view)

• Anoperating systemis aresource manager . Resource management includes

• • Transforming resources - to provide an easier to use version of a resource

• • Multiplexing resources - create the illusion of multiple resources

• • Scheduling resources - when and who gets a resource

• The hardware resources it manages include

• • Processors - process management system

• • Memory - memory management system

• • I/O devices - I/O system

• • Disk space - file system

13. What is an Operating System (4)

• The hardware resources are transformed into virtual resources so that an operating system may be viewed as providing avirtual computers , one to each user. Avirtual machine(top down view) consists of

• • Processes - virtualization of the computer including a virtual processor that abstracts the cpu - user mode instruction set + system calls

• • Virtual memory - virtualization of physical memory

• • Logical devices - virtualization of physical devices

• • Files - virtualization of disk space

14. What is an Operating System (5)

• The general functions of an operating system

• • Allocation - assigns resources to processes needing the resource

• • Accounting - keeps track of resources - knows which are free and which process the others are allocated to.

• • Scheduling - decides which process should get the resource next.

• • Protection - makes sure that a process can only access a resource when it is allowed

• Basic Functions

• • Process management

• • Resource management

• • • Device managment

• • • Memory management

• • • File management

15. History of Operating Systems (1)

• First generation 1945 - 1955

• • Technology:vacuum tubes & plugboards

• • Programming:setting some switches

• • Programming language:machine language

• • Tasks:tables of sine, cosine, logarithms

• • OS:none

16. A Famous Remark

• "I think there is a world market for maybe five computers."

• • Thomas Watson, chairman of IBM - 1943

17. History of Operating Systems (2)

• Second generation 1955 1965

• • Technology:Transistors

• • Programming:Punched cards

• • Programming languages:FORTRAN & Assembly

• • Tasks:Scientific

• • Computer:Mainframes

• • OS:Batch system

• Universities started to buy computers (millions $)

18.

• • bring cards to IBM 1401 machine (good at card reading)

• • read cards to tape

• • put tape on IBM 7094 which does computing

• • put tape on IBM 1401 which prints output offline

Early Batch System 19. Famous Remarks

• "I have traveled the length and breadth of this country and talked with the best people, and I can assure you that data processing is a fad that won't last out the year.

• • The editor in charge of business books for Prentice Hall - 1957

20. History of Operating Systems (3)

• Third generation 1965 1980

• • Technology:ICs

• • Programming:Punched card