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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.
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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
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 • What Types of Microcomputers Are Used Today? • Desktops and laptops • Servers – provide services to other computers • Handheld devices – designed for a specific purpose
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 • Since the 386DX, Intel Microprocessors support three modes • Real mode • 286 protected mode • 386 protected mode
Microprocessor (continued) • Real mode • Intel processors power up in this mode • Total address space = 1MB • 640KB limit for OS and application • Single-tasking • 286 protected mode • Total address space = 16 MB • Can multitask certain applications • Does not support virtual machines • 386 protected mode • Total address space = 4GB • Supports the use of virtual machines • Multitasking
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
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
What’s Contained in and Attached to a Microcomputer? • Memory • Chips that store programs and data • Random-access memory (RAM) • Read-only memory (ROM) • 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
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
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
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
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 • 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
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
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
Purpose, Types, and Functionsof Microcomputer Operating Systems • What is an Operating System? • An Operating System is: • The central control program for a computer • The intermediary between applications & hardware • Operating System Functions • User interface • Job management • Task management • Memory Management • File management • Device management • Security
Purpose, Types, and Functionsof 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
Purpose, Types, and Functionsof 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 • Memory Management • Manages placement of programs and data in memory • Virtual memory manager moves code and data to virtual memory (file on hard drive)
Purpose, Types, and Functionsof 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
Purpose, Types, and Functionsof 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
Purpose, Types, and Functionsof 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
Purpose, Types, and Functionsof Microcomputer Operating Systems • Categories of Operating Systems • Single-User/Single-tasking • Single-User/Multitasking • Multi-User/Multitasking • Real-Time
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
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
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
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.
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
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
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
DOS from Microsoft Windows NT Windows 98 Windows ME Windows 2000 Windows XP Macintosh OSs UNIX Linux Desktop OSs Available Today
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
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
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 • 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
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
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
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
Desktop OSs Available Today • Macintosh Operating Systems • Only run on Apple Macintosh computers • Mac OS 9 and Mac OS X common today • Macintosh hardware and software are proprietary products of Apple Computer Company • Macintosh computers generally use the PowerPC chip with an architecture that is enhanced for graphics and multimedia
Desktop OSs Available Today • UNIX • Introduced by Bell Labs Computing Science Research Center (Bell Labs) as UNIX Ver 6 in 1975 • A portable operating system for mini-computers and mainframes • Supports timesharing and multi-user systems • An excellent server operating system as it utilizes resources carefully, allowing only the required services to be loaded • 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
Desktop OSs Available Today Linux • Modeled on UNIX • Named for original developer, Linus Torvalds • Begun in 1991 by Torvalds and others as open-source for modern computers. • Written in the C language using GNU C Compiler (GCC) • 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
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
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
Chapter Summary Purpose and Functions of MicrocomputerOperating 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
Chapter Summary Purpose and Functions of MicrocomputerOperating 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.
Chapter Summary Purpose and Functions of MicrocomputerOperating 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
Chapter Summary Purpose and Functions of MicrocomputerOperating 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
Chapter Summary Purpose and Functions of MicrocomputerOperating 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
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
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 9, Mac OS X, and several versions of UNIX and Linux • Each of today’s common operating systems is best suited for certain uses
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