Fall 2009
Lecture 1
Operating Systems: Configuration & Use
CIS345
Introduction to Operating Systems
Mostafa Z. Ali
mzali@just.edu.jo
1-1
Chapter
1
Introduction to Operating Systems
An Overview of Microcomputers
What’s Contained in and Attached to a Microcomputer?
Purpose, Types, and Functions of Microcomputer Operating Systems
Yesterday’s Operating Systems
Desktop OSs Available Today
Learning Objectives
• Describe the microcomputers in use today
• Identify common computer hardware components
• Describe the purpose and functions of microcomputer operating systems
• Describe major events in the evolution of microcomputer operating systems
• List and compare the common microcomputer operating systems
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An Overview of Microcomputers
• What is a Microcomputer?
– A computer built around a microprocessor
• Microprocessor performs calculations or processing • A personal computer (PC) is a microcomputer that complies with hardware standards set and supported by Microsoft and Intel
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An Overview of Microcomputers
• What Types of Microcomputers Are Used Today?
– Desktops and laptops
– Servers – provide services to other computers
– Handheld devices – designed for a specific purpose
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What’s Contained in and Attached to a Microcomputer?
• Microprocessor
– Also known as the CPU or processor
– Central component of a microcomputer
– Performs calculations
– One or more per microcomputer
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What’s Contained in and Attached to a Microcomputer?
• Microprocessor (continued)
– Since the 386DX, Intel Microprocessors support three modes: • Real mode • 286 protected mode
• 386 protected mode
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What’s Contained in and Attached to a Microcomputer?
• Microprocessor (continued)
– Real mode
• Intel processors power up in this mode
• Total address space = 1MB
• 640KB limit for OS and application • Single‐tasking
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What’s Contained in and Attached to a Microcomputer?
• Microprocessor (continued)
– 286 protected mode • Total address space = 16 MB
• Can multitask certain applications
• Does not support virtual machines
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What’s Contained in and Attached to a Microcomputer?
• Microprocessor (continued)
– 386 protected mode
• Total address space = 4GB
• Supports the use of virtual machines
• Multitasking
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What’s Contained in and Attached to a Microcomputer?
• Microprocessor (continued)
– Processors can work with 8‐bit, 16‐bit, 32‐bit, and 64‐bit chunks of data
– The number of bits (binary digits) is the size of data that can be processed at one time
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What’s Contained in and Attached to a Microcomputer?
• Motherboard and Chipset
– Motherboard – central circuit board
– Contains one or more CPU slots or sockets into which the processor is plugged
– Chipset, memory slots, voltage regulator module (VRM), ROM BIOS, and the expansion bus slots are components of a motherboard
– Chipset controls the flow of signals to and from the processor and other components
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What’s Contained in and Attached to a Microcomputer?
• Memory
– Chips that store programs and data
– Random‐access memory (RAM)
– Read‐only memory (ROM)
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What’s Contained in and Attached to a Microcomputer?
• Memory (continued)
– RAM
•
•
•
•
System, main, or physical memory
Used by active programs
One or more circuit cards with memory chips
Volatile – all is lost when the computer is powered off
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What’s Contained in and Attached to a Microcomputer?
• Memory (continued)
– ROM BIOS
• Stores programs permanently
• Called ‘firmware’ since it is non‐volatile
– ROM BIOS contains:
• Code for starting the computer
• Code for controlling communications between the processor and other components • A setup program for configuring system options
• Configuration information stored in a special kind of non‐volatile RAM called the CMOS RAM
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What’s Contained in and Attached to a Microcomputer?
• ROM BIOS configuration information – Disk drive types and capacity
– Disk boot order
– System memory
– Connectors (ports)
– Power management
– Other information determined by
motherboard and ROM BIOS manufacturers
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What’s Contained in and Attached to a Microcomputer? • Video Adapter and Display
– Video adapter – circuitry that sends the controlling output signals to the display screen
– Display screen – a monitor or a flat panel display (FPD) for visual output from the computer
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What’s Contained in and Attached to a Microcomputer?
• Keyboard
– An input device with a typewriter style layout of alphanumeric and punctuation keys
– Includes additional function, control, arrow, and editing keys
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What’s Contained in and Attached to a Microcomputer? • Pointing Device
– Required to move a graphical pointer (cursor) around in a GUI
– Mouse is the most common pointing device –
connects via a physical cable or a wireless connection.
– Other pointing devices: touch pad, track ball, joystick, and light pen
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What’s Contained in and Attached to a Microcomputer? • Disk Drives
– Store data and programs
– Encoded on surface of small spinning platters
– Magnetic or optical technology
– Floppy drives and hard disk drives use magnetic technology
– Compact disk (CD) and digital versatile disk (DVD) drives use optical technologies
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What’s Contained in and Attached to a Microcomputer? • Peripheral Devices
– Broad term for nonessential add‐on devices
– Includes printers, scanners, pointing devices, digital cameras, external modems, and disk drives
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Purpose, Types, and Functions
of Microcomputer Operating Systems
• What is an Operating System? – An Operating System is:
• The central control program for a computer
• The intermediary between applications & hardware
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Purpose, Types, and Functions
of Microcomputer Operating Systems
• Operating System Functions
– User interface
– Job management
– Task management
– Memory Management
– File management
– Device management
– Security
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Purpose, Types, and Functions
of Microcomputer 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
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Purpose, Types, and Functions
of Microcomputer 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
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Purpose, Types, and Functions
of Microcomputer 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)
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Purpose, Types, and Functions
of Microcomputer 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
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Purpose, Types, and Functions
of Microcomputer 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
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Purpose, Types, and Functions
of Microcomputer 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
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Purpose, Types, and Functions
of Microcomputer Operating Systems
• Categories of Operating Systems
– Single‐User/Single‐tasking
– Single‐User/Multitasking
– Multi‐User/Multitasking
– Real‐Time 1-30
Yesterday’s Operating Systems
• First the machines…
– Charles Babbage designed the first computer in the 1820s
– Apple II was the first microcomputer to combine critical elements like keyboard, monitor, operating system, and desirable and useful applications
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Yesterday’s Operating Systems
• Then the Operating Systems
– Early single‐purpose computers included system functions
– OSs did not exist as separate entity
– OSs evolved from need for multipurpose computers
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Yesterday’s Operating Systems
• DOS, CP/M, Apple, and the Killer App
– To be widely accepted a computer needed a ‘killer app’
– VisiCalc was the killer app of 1970’s micro‐
computers – VisiCalc ran under the CP/M OS – VisiCalc contributed to the success of the Apple II – Both PC DOS and a version of CP/M were available for the IBM PC 1-33
Yesterday’s Operating Systems
• The Second Wave (second killer app)
– Lotus 1‐2‐3 – a DOS spreadsheet application that is fast and provides added functionalities
– Lotus 1‐2‐3 became the killer app for the IBM‐PC/PC DOS combination.
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Yesterday’s Operating Systems
• OS/2 (Operating System/2) – Version 1.0 introduced in 1987
– Developed by Microsoft and IBM – 1.0 had costly memory and disk requirements
– IBM introduced OS/2 Warp in 1990’s – IBM has ended development of new versions
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Yesterday’s Operating Systems
• Microsoft Windows
– 1985 first version – GUI on top of DOS
– Windows 3.0, introduced in 1990, 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 1-36
Yesterday’s Operating Systems
• Windows for Workgroups – DOS and earlier versions of Windows had no networking
– Windows for Workgroups 3.1 and 3.11 enabled peer‐to‐peer networking
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Desktop OSs Available Today •
•
•
•
DOS from Microsoft
Windows NT
Windows 98
Windows ME
•
•
•
•
•
Windows 2000
Windows XP
Macintosh OSs
UNIX
Linux
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Desktop OSs Available Today
• DOS from Microsoft
– DOS provides support for interaction with disk drives
– Microsoft’s first version of DOS, called PC DOS
– Introduced with the first IBM‐PC in 1981
– Each major version of DOS supported new disk capacities
– DOS has a text‐mode command line interface
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Desktop OSs Available Today
• Windows NT – First Microsoft OS to take full advantage of the capabilities of the Intel’s 386 protected mode
– Two main versions of NT – one for servers and another for desktop computers
– Windows NT 4.0, introduced in 1996, has a GUI similar to Windows 95
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Desktop OSs Available Today
• Windows 98 – An evolutionary development compared to the earlier Windows operating system in terms of GUI and integrated components
– New options for customizing the GUI, including tighter integration with Microsoft’s Web browser, Internet Explorer (IE)
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Desktop OSs Available Today
• Windows 98 (continued)
– Comes with drivers and support for devices like DVD drives
– It was the choice for PCs with plug and play (PnP) hardware, not supported by Windows NT
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Desktop OSs Available Today
• Windows Me
– Introduced in 2000 as an upgrade to Windows 98
– Improved music, video, and home networking support
– Provides utilities as well as applications for dealing with PC software configuration, digital music, and video
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Desktop OSs Available Today
• Windows 2000
– Family of OS products, introduced in 2000
– Combines the best of Windows 98 and Windows NT
– Windows 2000 Professional, Windows 2000 Server, Windows 2000 Advanced Server, and Windows 2000 Enterprise Edition 1-44
Desktop OSs Available Today
• Windows XP
– Several products, but no server version
– Most common are Windows XP Home Edition and Windows XP Professional
– Improved GUI as well as several network‐ and security‐related features
– Default desktop only contains the Recycle Bin
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Desktop OSs Available Today
• Macintosh Operating Systems
– Designed to run on Apple Macintosh computers, but “can be” installed on a regular PC (Intel‐based)
– Mac OS X Leopard, and Mac OS X Snow Leopard are common today
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Desktop OSs Available Today
• Macintosh Operating Systems (continued)
– Macintosh computers generally use the PowerPC chip with an architecture that is enhanced for graphics and multimedia
1-47
Desktop OSs Available Today
• UNIX
– Introduced by Bell Labs Computing Science Research Center (Bell Labs) as UNIX Version 6 in 1975
– A portable operating system for mini‐computers and mainframe computers
– Supports timesharing and multi‐user systems
– An excellent server operating system as it utilizes resources carefully, allowing only the required services to be loaded
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Desktop OSs Available Today • UNIX (continued)
– The current commercial versions of UNIX include Sun Microsystems’ Solaris, Hewlett‐
Packard’s HP‐UX, IBM’s AIX, and Compaq’s Tru64 UNIX
– Many open source versions of UNIX are also available, which can be changed according to requirements
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Desktop OSs Available Today
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 GNU C Compiler (GCC)
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Desktop OSs Available Today
Linux (continued)
– Distributed free
– Vendors sell bundles with extras (utilities, GUIs, manuals)
– Novell, Red Hat, and others distribute such bundles
– Fastest‐growing computer server OS
– Making inroads on desktop computers
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Chapter Summary Microcomputers Today
– A computer consists of hardware, applications software, and operating system software
– The operating system allows the user to interact with the computer hardware
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Chapter Summary
Common Microcomputer Hardware
– The basic components of a microcomputer are processor, motherboard, memory, video adapter and display, keyboard, pointing device, disk drives, and peripheral devices
– You can identify hardware components by a visual inspection, by observing information displayed during the boot up process, and by accessing a ROM BIOS setup program
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Chapter Summary
Purpose and Functions of Microcomputer
Operating systems
– Certain functions are provided by most, if not all, current operating systems. These functions include a user interface, job management, task management, memory management, file manage‐
ment, device management, and security. – The operating system makes everything work together
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Chapter Summary
Purpose and Functions of Microcomputer
Operating systems
– You can identify most of the functions provided by your operating system by careful observation. For instance, evidence of support of the security function includes a required logon procedure when you start your computer, and the need for authorization to access resources on your local computer. 1-55
Chapter Summary
Purpose and Functions of Microcomputer
Operating systems
– There are four categories of operating systems: •
•
•
•
Single‐User/single‐tasking
Single‐User/multitasking
Multi‐User/multitasking
Real‐Time – A Single‐User/single‐tasking operating system is one that allows only a single user to perform a single task at a time
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Chapter Summary
Purpose and Functions of Microcomputer
Operating systems
– An operating system that allows a single user to perform two or more functions at once is a Single‐
User/multitasking operating system – A Multi‐User/multitasking operating system is an operating system that allows multiple users to run programs simultaneously on a single network server, called a terminal server 1-57
Chapter Summary
Purpose and Functions of Microcomputer
Operating systems – Real‐time operating systems are defined by their speed and ability to work with special real‐time applications programs. A Real‐time operating system is a very fast, relatively small OS that is often embedded, meaning it is built into the circuitry of a device and not normally loaded from a disk drive 1-58
Chapter Summary
Major Events in the Evolution of Microcomputer Operating Systems
– The history of current microcomputers and their OSs involved many technical advances and the imagination of a multitude of innovative people – You can find many accounts of the history of computers and operating systems by searching the Internet 1-59
Chapter Summary
What OSs Are Available Today?
– The microcomputer operating systems common today include MS‐DOS, several versions of Windows (Windows 98, Windows 2000, and Windows XP), Mac OS X, and several versions of UNIX and Linux – Each of today’s common operating systems is best suited for certain uses 1-60
Chapter Summary
What OSs Are Available Today?
– Microsoft desktop OSs are common in the business environment – Both UNIX and Linux can be found on high‐
end servers and on desktop computers. The use of Linux is growing on all types of systems – The Mac OSs are commonly used in education and in graphic workstations 1-61