1. Introduction to Operating Systems
Chapter 1
Introduction to Operating Systems
McGraw-Hill

2. Learning Objectives
LO 1.1 Describe the purpose and functions of operating systems LO 1.2 Describe major events in the evolution of operating systems LO 1.3 List and compare the common operating systems in use today

3. An Overview of Operating Systems
What is a Microcomputer?
A computer built around a microprocessor
Microprocessor is a special integrated circuit (IC) that performs calculations and processing
An IC (chip) is a small electronic component made up of transistors and other miniaturized parts
Microprocessor also called central processing unit (CPU)
Many other ICs in a computer

4. A typical PC with components

5. An Overview of Operating Systems
What’s Inside a Microcomputer?
A least one CPU
Motherboard
RAM
ROM BIOS
Also attached
Keyboard
Display
Printer
Pointing Device and much more

6. An Overview of Operating Systems
What’s Inside a Microcomputer?
More About ROM BIOS
Program code for basic control of devices
Many components contain additional ROM BIOS
Device drivers install in OS for each device
ROM BIOS includes power-on-self test (POST)

7. Figure 1-1 An example of a BIOS start-up message

8. An Overview of Operating Systems
What’s Types of Microcomputers are in Use Today?
Desktops and Laptops
Servers
Handheld Devices
Growing number and types
Most popular are smartphones (iPhone, BlackBerry, etc.)

9. A PC laptop

10. Two MacBook laptops

11. An Overview of Operating Systems
Functions of Operating Systems
An Operating System is:
The central control program(s) for a computer
Loads when computer is turned on
Kernel (main component) remains in memory
Manages low-level OS tasks
Acts as intermediary between applications & hardware

12. An Overview of Operating Systems
Functions of Operating Systems
User interface
Job management
Task management
Memory Management
File management
Device management
Security

13. The functions of an operating system

14. An Overview of Operating Systems
User Interface
AKA the ‘shell’
A software layer for user interaction
Includes the command processor
Includes the visual components of the OS
Character-based command line
GUI

15. Figure 1-2 MS-DOS prompt

16. Figure 1-3 A typical GUI screen

17. An Overview of Operating Systems
Job management
Controls the order and time in which programs are run
Task management
Found in multitasking operating systems
Controls the focus
Allows user to switch between tasks

18. An Overview of Operating Systems
Memory Management
Manages placement of programs and data in memory
Virtual memory manager moves code and data to virtual memory (file on hard drive)

19. An Overview of Operating Systems
File Management
AKA data management
Allows the OS to read, write, and modify data
Data is organized into files
Allows users to organize their files into containers called folders or directories

20. An Overview of Operating Systems
Device Management
Controls hardware through device drivers
A device driver is unique to a device
Created by the manufacturer of the device to work with a specific operating system

21. An Overview of Operating Systems
Security
Provides password-protected authentication of the user before allowing access
Checks user name and password
Restricts the actions that can be performed on a computer, customized for each user

22. An Overview of Operating Systems
Categories of Operating Systems
Single-User/Single-tasking
Single-User/Multitasking
Multi-User/Multitasking
Real-Time
16-, 32-, and 64-bit OSs

23. Figure 1-4 Single-user/single-tasking

24. Figure 1-5 Single-user/multitasking

25. Figure 1-6 Multiuser/multitasking

26. Figure 1-7 Example of a device containing a real-time embedded system

27. Table 1-1 Windows Memory Limits

28. Yesterday’s Operating Systems
UNIX–The OS for All Platforms
1975: UNIX version 6 emerged from Bell Labs Computing Science Research Center (Bell Labs)
OS for many platforms
Free versions: BSD, Net BSD, Open BDS, & Open Solaris. Commercial versions: AIX, OpenServer (derived from SCO UNIX), & HP/UX
Traditional CLI shell
GNOME and KDE GUIs

29. Yesterday’s Operating Systems
The Evolution of Microcomputer OSs (cont.)
Theoretical designs started as early as the 1820’s
Early computers were single-purpose, with no need for OS
1970s: TRS-80 and Apple II microcomputers
OSs evolved from need for multipurpose computers

30. Yesterday’s Operating Systems
The Evolution of Microcomputer OSs (cont.)
The Killer App
VisiCalc spreadsheet helped sell the Apple II
First IBM-PC sold without a killer app
DOS outsold CP/M for IBM-PC due to pricing
The Second Killer App
Lotus 1-2-3, a DOS-based spreadsheet
Created need for IBM/PC
VisiCalc ran on the CP/M OS

31. Figure 1-8 Lotus 1-2-3 spreadsheet

32. Yesterday’s Operating Systems
The Evolution of Microcomputer OSs (cont.)
Apple OS for Apple I and Apple II (non-GUI)
1976: Steve Jobs created Apple I and founded Apple Computer
1977: Apple introduces Apple II at the West Coast Computer Faire in San Francisco
1978: Added disk drives for Apple II
GUI Apple OSs
1982: Apple Lisa computer
1984: Macintosh computer

33. Yesterday’s Operating Systems
The Evolution of Microcomputer OSs (cont.)
GUI Apple OSs (cont.)
1999: Mac OS 9
Multi-user
Weak in memory management and multitasking
2001: Mac OS X
First Mac OS based on UNIX
Has both a GUI and a CLI

34. Yesterday’s Operating Systems
The Evolution of Microcomputer OSs (cont.)
MS-DOS
1981: IBM-PC with PC-DOS by Microsoft
Single-tasking with very limited memory support
No native GUI
No built-in security functions
Microsoft developed several versions of MS-DOS

35. Figure 1-9 MS-DOS prompt with the Format command

36. Yesterday’s Operating Systems
The Evolution of Microcomputer OSs (cont.)
OS/2 (Operating System/2)
1987: Version 1.0 introduced
Developed by Microsoft and IBM
1.0 had costly memory and disk requirements
1990’s: IBM introduced OS/2 Warp mainly for servers
2003: IBM ended development of new versions
2004: IBM sold PC division to China-based Lenovo Group
Students will learn more about DOS in Chapter 4.

37. Yesterday’s Operating Systems
The Evolution of Microcomputer OSs (cont.)
Microsoft Windows
Version is a new level of Windows OS
Edition is a unique product based on a version (several editions per version)
1985: Windows 1 – a GUI on top of DOS
1990: Windows 3.0 provided better support for legacy DOS applications
Windows 3.x works in Real mode, Standard mode, and 386 Enhanced mode
1992: Windows 3.1 successful with MS Office

38. Figure 1-10 Windows 3.1 desktop

39. Yesterday’s Operating Systems
The Evolution of Microcomputer OSs (cont.)
Windows for Workgroups
DOS and earlier versions of Windows had no built-in network support
1992: Windows for Workgroups 3.1 and enabled peer-to-peer networking
Still dependent on DOS

40. Yesterday’s Operating Systems
The Evolution of Microcomputer OSs (cont.)
Windows NT
1993: First Microsoft OS to take full advantage of the capabilities of the Intel 386 protected mode
Two main versions of NT – one for servers and another for desktop computers
1996: Windows NT 4.0 with a GUI similar to Windows 95
Microsoft no longer sells or supports Windows NT

41. Figure 1-11 Windows NT 4.0 desktop with open windows

42. Yesterday’s Operating Systems
The Evolution of Microcomputer OSs (cont.)
Windows 95
1995: Windows 95 introduced; predated Windows NT Workstation
A continuation of the Windows 3.X model: GUI on top of DOS
Both 16-bit and 32-bit code
A new GUI

43. Yesterday’s Operating Systems
The Evolution of Microcomputer OSs (cont.)
Windows 98
1998: An upgrade to Windows 95
More stable
Greater integration with Internet Explorer
More customization options
Support for new devices like DVD drives
Drawback: Lacked local security

44. Figure 1-12 MS Windows 98 desktop with open windows

45. Yesterday’s Operating Systems
The Evolution of Microcomputer OSs (cont.)
Windows Me
2000: An upgrade to Windows 98
Improved music, video, and home networking support
Provided both utilities and applications for dealing with PC software configuration, digital music, and video
Last Windows version based on Windows 95 kernel
Targeted the home market

46. Yesterday’s Operating Systems
The Evolution of Microcomputer OSs (cont.)
Windows 2000
Windows 2000: Introduced in several editions
Windows 2000 Professional (for desktops and laptops)
Windows 2000 Server
Windows 2000 Advanced Server
Windows 2000 Enterprise Edition
Combines the best of Windows 98 and Windows NT

47. Figure 1-13 MS Windows 2000 desktop

48. Yesterday’s Operating Systems
The Evolution of Microcomputer OSs (cont.)
Windows XP
2001: Several editions, but no server version
Most common:
Windows XP Home Edition
Windows XP Professional (enhanced security features)
Windows XP Media Edition
Most editions were 32-bit
Windows XP 64-bit Edition for Intel Itanium processor platform
Support life cycle for XP is ending
Support is ending, but XP is on many desktops, and will remain on many for a few more years.

49. Figure 1-14 MS Windows XP desktop with open windows

50. Table 1-2: Summary of Current Desktop OSs
Today’s Desktop OSs
Point out that the following chapters in this book go into more detail on the current desktop OSs (Windows Vista/7, Linux, and Mac OS X), as well as DOS.
A chapter on Windows XP is also included because it still exists on many desktops. Only since the introduction of Windows 7 have we seen the number of Windows XP desktops begin to dwindle.
Table 1-2: Summary of Current Desktop OSs

51. Today’s Desktop OSs Windows Vista 2007: A new GUI, other improvements
But not widely adopted

52. Figure 1-15 The Windows Vista desktop

53. Today’s Desktop OSs Windows 7
Improvements that solved problems with Vista

54. Figure 1-16: The Windows 7 desktop

55. Today’s Desktop OSs Windows File Systems FAT file systems NTFS
FAT12, FAT16, FAT32, exFAT
Logical structure includes file allocation table and special files called directories
NTFS
Introduced in Windows NT
In subsequent Windows except Windows 9x and Windows Me
Supports very large disk volumes and security

56. Today’s Desktop OSs Windows File Systems
File systems for optical drives
CD-ROM File System (CDFS)
Universal disk Format (UDF)
Live File System

57. Today’s Desktop OSs Mac OS X
Apple used proprietary hardware and software
Mid-1990s to 2005: Apple used Motorola PowerPC
2005 to present: Intel platform
Mac OS X is only licensed to run on Apple computers

58. Figure Mac OS X GUI

59. Today’s Desktop OSs Linux Modeled on UNIX
Named for original developer, Linus Benedict Torvalds
Begun in 1991 by Torvalds and others as open-source for modern computers
Written in the C language using the GNU C Compiler (GCC)
Many free or inexpensive bundles

60. Today’s Desktop OSs Linux (cont.)
Available in both 32-bit and 64-bit distributions
Multitasking / multi-user
Novell, Red Hat, and others distribute such bundles
Fastest-growing computer server OS
Making inroads on desktop computers
Supports several file systems
Old Minux, ext, ext2
Journaling in ext3, ReiserFS, JFS, XFS
Point out that the Linux file systems offer file-level security.

61. Figure 1-18 Red Hat Linux directory listing (ls command)

62. Chapter 1 Summary LO1.1 An Overview of Operating Systems
A computer consists of hardware and two types of software: operating system software and applications software.
The operating system allows the user to interact with the computer hardware.
Certain computer hardware is common to most computers. The basic components include the processor, motherboard, RAM, ROM BIOS, video adapter, display screen, keyboard, pointing device, and other peripherals.

63. Chapter 1 Summary LO1.1 An Overview of Operating Systems (cont.)
Common computers in use today include desktops, laptops, server systems, and handheld devices.
Most, if not all, current operating systems provide a user interface, job management, task manage-ment, memory management, file management, device management, and security.
There are four categories of operating systems: single-user / single-tasking, single-user / multi-tasking, multiuser/multitasking, and real-time.

64. Chapter 1 Summary LO1.1 An Overview of Operating Systems (cont.)
Today’s popular operating systems for desktops and laptops come in versions for 32-bit and 64-bit processing. The biggest advantage of a 64-bit OS over a 32-bit version of the same OS is that the amount of memory supported is much greater in a 64-bit OS.

65. Chapter 1 Summary LO 1.2 Yesterday’s Operating Systems
The history of current computers and their OSs involved many technical advances and the imagination of a multitude of innovative people.
UNIX is the oldest popular operating system and comes in versions for very large computers, as well as microcomputers. It is a portable OS that is usable on a variety of computer system platforms, with only minor alterations required for the underlying architecture.

66. Chapter 1 Summary LO 1.2 Yesterday’s Operating Systems (cont.)
Early microcomputers included the MITS Altair 8800, the Apple I and Apple II, Radio Shack’s TRS-80, and the Commodore, all introduced in the 1970s. The Apple computers came with the Apple OS.
Certain “killer apps,” notably VisiCalc and Lotus 1-2-3, made microcomputers appeal to ordinary people who were attracted to programs that automated formerly manual tasks

67. Chapter 1 Summary LO 1.2 Yesterday’s Operating Systems (cont.)
IBM introduced the PC in 1981, and it far exceeded the expectations of IBM with Microsoft BASIC in ROM and PC DOS for computers with a floppy disk drive.
Microsoft made MS-DOS available to third-party PC manufacturers.
Microsoft Windows evolved from the first version in 1985 to Windows 7, introduced in 2009.

68. Chapter 1 Summary LO 1.2 Yesterday’s Operating Systems (cont.)
The Apple Mac computer, introduced in 1984, came with the MAC OS System. This OS line continued through Mac OS 9, introduced in 1999, and phased out after Mac OS X was introduced 2001

69. Chapter 1 Summary LO 1.3 Today’s Desktop Operating Systems
The operating systems common today include Windows XP, Windows Vista, Windows 7, Mac OS X, and Linux.
Windows supports several file systems for hard drives and optical disks. The most feature-rich and secure file system for hard drives is the NTFS file system.

70. Chapter 1 Summary LO 1.3 Today’s Desktop Operating Systems (cont.)
Mac OS X, based on NextStep, an OS with a UNIX kernel, runs only on Apple Macintosh computers, and while it supports several file systems, the preferred file system for hard drives is HFS+.
Linus Torvalds developed Linux as a collaborative effort beginning in A full multitasking / multiuser operating system, it is available in both 32-bit and 64-bit distributions and can run on nearly any computer.

71. Chapter 1 Summary LO 1.3 Today’s Desktop Operating Systems (cont.)
Linux supports several file systems for hard drives and optical disks. The most feature-rich and secure file system for hard drives is the ext3 file system.