1. Lecture 13 Operating Systems
Introduction to Information Technology
Lecture 13 Operating Systems
Dr. Ken Tsang 曾镜涛
Room E408 R9
With thanks to Dr. HP Guo

2. Outline Software Basics What is an Operating System
History of Operating Systems
Booting the Computer
Functions of Operating Systems
Types of Operating Systems
Utility Programs in Windows XP

3. The Computer Level Hierarchy

4. Software Basics Computer = Hardware + Software Software
Application software
Address users' specific needs in the real world
word processing, music software, image editing, games, database programs, inventory control systems, etc.
System software
Operating system
Device drivers
Utilities
Programming software tools (compilers, debuggers, etc.)

5. Computer System

6. Who Creates Computer Software?
Programmers
High-level language, easy for humans
C++, Java, etc
Low-level language, used by CPU
Machine language
Compiler
Translate high-level language into low-level language

7. Compilation

8. Operating Systems
A set of programs containing instructions that maintain and manage the computer resources, such as CPU, memory and input/output devices
Provide an interface through which the user can interact with the computer
The core of a computer’s system software

9. History of Operating Systems
Batch processing
Professional operators (humans!) combined decks of cards into batches, or bundles, with the appropriate instructions allowing them to be processed with minimal intervention
A program called a resident monitor allowed programs to be processed without human interaction

10. History of Operating Systems
Resident Monitors
Monitors were the precursors of modern day operating systems
The monitor started the job, gave control of the computer to the job, and when the job was done, the monitor resumed control of the machine

11. Spooling
Increases in CPU performance made punched card batch processing less efficient
Magnetic tape (as buffer) offered one way to process decks faster
SPOOLing
Simultaneous Peripheral Operation Online
Allows I/O and CPU computations to occur in parallel
the simplest form of multiprogramming
Spooling example: print spooling

12. History of Operating Systems
Multiprogramming Systems
allow several executing programs to be in memory concurrently
Timesharing system
permits many users to share the same CPU
the CPU switches between user sessions very quickly, giving each user a small slice of processor time

13. Evolution of Operating Systems
First-generation computers
Hardware: vacuum tubes and relays
Human operators
Second-generation Computers
Hardware: transistors
Batch processing was introduced as a means to keep the CPU busy
Monitors helped with the processing
spooling

14. Evolution of Operating Systems
Third-generation computers
Hardware: integrated circuits
timesharing
Fourth-generation Computers
Hardware: VLSI
Today’s multi-task, multi-user operating systems

15. Functions of an Operating System?
start the computer
provide a user interface
manage programs
administer security
manage memory
control a network
provide file management and other utilities
monitor performance
establish an Internet connection
schedule jobs and configure devices

16. Start the Computer What is booting?
Process of starting or restarting a computer
Cold boot Turning on computer that has been powered off
Warm boot Restarting computer that is powered on

17. Dual-Boot
Dual-Boot permits two or more operating systems to be installed on one computer

18. How does a personal computer boot up?
Step 1. Power supply sends signal to components in system unit
Step 4. Results of POST are compared with data in CMOS chip
Step 5. BIOS looks for system files in floppy disk drive or CD/DVD drive, and then hard disk
Step 2. Processor accesses BIOS to start computer
Step 6. Kernel (core) of operating system loads into RAM
Step 3. BIOS runs tests, called the POST, to check components such as mouse, keyboard, and adapter cards
Step 7. Operating system loads configuration information and displays desktop on screen

19. User Interface What is a user interface?
Controls how you enter data and instructions and how information displays on screen
menu-driven interface
command-line interface

20. GUI Graphical User Interface
User interacts with menus and visual images such as icons and buttons

21. File System
Hierarchical Directories

22. Windows File naming Four parts C:\Windows\System\WinTrust.hlp Drive
Path
File name
File type (extension)
C:\Windows\System\WinTrust.hlp

23. Single User / Multitasking
Working on two or more programs that reside in memory at same time
Foreground contains program you are using
Background contains programs that are running but are not in use

24. Memory Management Optimizing use of random access memory (RAM)
With virtual memory (VM), portion of hard disk is allocated to function as RAM
This process is called paging
When an OS spends much of its time paging, instead of executing application software, it is said to be thrashing

25. Scheduling Job Jobs A job is operation the processor manages
Adjusts schedule based on job’s priority
Jobs
Receiving data from input device
Sending information to output device
A job is operation the processor manages
Processing instructions
Transferring items between storage and memory

26. Spooling Sending print jobs to buffer instead of directly to printer
Print jobs line up in queue
Addresses the “slow-I/O vs fast-CPU” problem

27. Program that tells operating system how to communicate with device
Device Driver
Device Driver
Program that tells operating system how to communicate with device
With Plug and Play, operating system automatically configures new devices as you install them
Also called driver

28. Types of Operating System
Stand-Alone Operating Systems
works on a desktop computer, notebook computer, or mobile computing device
Network Operating Systems
designed specifically to support a network
Embedded Operating Systems
Found on most mobile computers, PDAs, and other small devices

29. DOS (Disk Operating System)
Developed in early 1980s for personal computers O
Used command-line interface when first developed, later included menus S
Hardly used today because it does not offer GUI

30. DOS: Dirty Operating System
Tim Paterson

31. Windows

32. More Windows

33. And More Windows

34. Coming soon: Windows Vista (Longhorn)

35. Windows Family Windows Version Year Released Windows 3.x 1990
Windows NT
Windows
Windows NT Workstation
Windows
Windows Millennium Edition 2000
Windows 2000 Professional 2000
Windows XP 2001
Windows XP SP2 2004

36. Windows XP Microsoft’s fastest, most reliable Windows operating system
Five editions: Home Edition, Professional Edition, Tablet PC Edition, Media Center Edition, and 64-bit Edition

37. Mac OS X Available only for computers manufactured by Apple
Macintosh operating system has been model for most GUIs

38. UNIX Used by power users because of its flexibility and power
Most versions offer GUI
Both a stand-alone and a network operating system

39. Unix: 1969
Ken Thompson
Dennis Ritchie
Father of C
Turing Award

40. Dennis: A Professional Truck Driver

41. Ken: A Chess Player
Belle: ACM chess tournament Championship in 80, 81, 82, 86

42. BSD Unix: 1977 BSD Unix vi BSD TCP/IP Co-founder of Sun
'It's very simple – you read the protocol and write the code.'"
BSD Unix vi
BSD TCP/IP
Co-founder of Sun
Sparc Microprocessor
NFS(Network File System)

43. Linux Popular, free, multitasking UNIX-type operating system
Open-source software
code is available to public
Both a stand-alone and a network operating system

44. GNU & Linux (1991)
Richard Stallman
Linus Torvalds

45. Others

46. Mac OS

47. Network OS NetWare UNIX / Linux Windows Server 2003 Solaris
Designed for client/server networks
Windows Server 2003
Upgrade to Windows 2000 Server
UNIX / Linux
Multi-purpose operating system
Solaris
Version of UNIX developed by Sun Microsystems
Specifically for e-commerce applications

48. Embedded OS What are two operating systems for PDAs?
Windows Mobile for Pocket PC
Palm OS for Palm, Visor, and CLIE

49. Symbian OS
Open-source, multitasking operating system designed for smart phones
Make telephone calls, save appointments, browse Web, send and receive and faxes, and more

50. Utility Program System software that performs maintenance-type tasks
Also called utility

51. Windows Explorer
File Manager

52. System Information

53. Windows Registry
A central record of all the settings and information relating to Windows and the software and hardware you have installed on your computer
Use Regedit to change it

54. Registry Editor

55. Summary Software Basics What is an Operating System
History of Operating Systems
Booting the Computer
Functions of Operating Systems
Types of Operating Systems
Utility Programs in Windows XP

56. The pdf slides and glossary are here: