1. Introduction to Operating Systems An Overview of Microcomputers What’s Contained in and Attached to a Microcomputer? Purpose, Types, and Functions.

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Introduction to Operating Systems

An Overview of MicrocomputersWhat’s Contained in and Attached to a Microcomputer?

Purpose, Types, and Functions of Microcomputer Operating Systems

Yesterday’s Operating SystemsDesktop OSs Available Today

Chapter

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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

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 Since the 386DX, Intel Microprocessors support three modes

Real mode

286 protected mode

386 protected mode

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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

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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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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)

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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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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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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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

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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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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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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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


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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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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)

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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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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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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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Categories of Operating Systems Single-User/Single-tasking Single-User/Multitasking Multi-User/Multitasking Real-Time

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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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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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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

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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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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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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

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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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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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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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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

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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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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

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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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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

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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

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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

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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 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

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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.

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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

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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

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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

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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

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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

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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. Introduction to Operating Systems An Overview of Microcomputers What’s Contained in and Attached to a Microcomputer? Purpose, Types, and Functions.

Documents

common microcomputer

functions of microcomputer

evolution of microcomputer

memory slots

memory romramsystem

memory chipsvolatile

modetotal address space

rom bios manufacturerswhats