Chapter 2 Hardware and Software. Information system users must work closely with information system...

Chapter 2

Hardware and Software

Information system users must work closely with information system professionals to define business needs, evaluate options, and select the hardware and software that provide a cost-effective solution to those needs Identify and discuss the role of the essential

hardware components of a computer systemList and describe popular classes of computer

systems and discuss the role of each

Fundamentals of Information Systems, Fourth Edition 2

Systems and application software are critical in helping individuals and organizations achieve their goals Identify and briefly describe the functions of the

two basic kinds of softwareOutline the role of the operating system and

identify the features of several popular operating systems


Do not develop proprietary application software unless doing so will meet a compelling business need that can provide a competitive advantageDiscuss how application software can

support personal, workgroup, and enterprise business objectives

Identify three basic approaches to developing application software and discuss the pros and cons of each


Choose a programming language whose functional characteristics are appropriate for the task at hand, considering the skills and experience of the programming staffOutline the overall evolution and

importance of programming languages and clearly differentiate among the generations of programming languages


The software industry continues to undergo constant change; users need to be aware of recent trends and issues to be effective in their business and personal life Identify several key software issues and

trends that have an impact on organizations and individuals


Hardware can improve productivity, increase revenue, reduce costs, and provide better service

Managers are expected to know about hardware To help define business needs To ask questions and evaluate options when

buying equipment Software is indispensable for any computer

system Systems software needed for input,

calculations, and output Application software aids in productivity


Choosing the right computer hardware requires understanding its relationship to the information system and needs of the organization

Hardware objectives are subordinate to, but supportive of, the information system and the current and future needs of the organization


Central processing unit (CPU)Arithmetic/logic unit (ALU): performs

calculations and makes logical comparisonsControl unit: accesses, decodes and

coordinates data in CPU and other devices Primary memory: holds program

instructions and data for processing Secondary storage: more permanent

storage Input and output devices Communications devices



Figure 2.1: Hardware Components

System unitHouses the components responsible for

processing (the CPU and memory) All other computer system devices are

linked either directly or indirectly into the system unit housing


Clock speed: series of electronic pulses produced at a predetermined rate that affects machine cycle timeClock speed is often measured in megahertz

(MHz), or millions of cycles per secondClock speed for personal computers is in the

multiple gigahertz (GHz), or billions of cycles per second, range


Physical characteristics of the CPUDigital circuits on chipsTo turn a digital circuit on or off, electrical

current flows through silicon



Table 2.1: Units for Measuring Computer Storage

Random access memory (RAM)TemporaryVolatile

Read-only memory (ROM)Usually nonvolatile


Multiprocessing: simultaneous execution of two or more instructionsMulticore microprocessor: shares workload

among two or more independent processors in a single computer

Parallel processing: links several processors to operate at the same time, or in parallel

Grid computing: collection of computers working to solve a common problem


Secondary storageAlso called permanent storageNonvolatileGreater capacity and greater economy than

memory Access methods, storage capacities, and

portability required are determined by the information system’s objectives


Sequential access: data must be accessed in the order in which it is storedSequential access storage devices (SASDs)

Direct access: data can be retrieved in any orderDirect access storage devices (DASDs)


Magnetic tapes Secondary storage used primarily for backups

Magnetic disks Direct access secondary storage, e.g., hard

disk RAID

Stores extra bits so that data can be reconstructed if system fails

SAN Provides high-speed connections between

data storage devices and computers over a network


Optical disksDirect access optical disc, e.g., CD-ROM

Digital video disk (DVD)Stores several gigabytes of data

Flash memoryNonvolatile silicon computer chip


Personal computer input devicesKeyboard, mouse

Speech-recognition technology Input devices that recognize human speech

Digital cameras Input device used with PC to record/store

images in digital form Terminals

Input and display devices that perform data entry and input at the same time


Touch-sensitive screensAllow display screens to act as input

devices as well as output devices Bar-code scanners

Employs a laser scanner to read a bar-coded label

Magnetic ink character recognition (MICR) devicesCode data on banking forms, such as

checks


Pen input devicesActivate a command, enter handwritten

notes, and draw objects Radio Frequency Identification (RFID)

Employs a microchip with an antenna to broadcast its unique identifier and location to a receiver


Display monitors (CRTs)Output quality measured by number of

pixels and dot pitch Liquid crystal displays (LCDs)

Easier on eyes, use less electricity, take up less space than CRTs

Organic light-emitting diodes (OLEDs)Directly emits light rather than using

backlightSharper colors and thinner displays


Printers and plotters: hard copy outputPrinters: laser, inkjet Plotters: used for general design work

Digital audio playerStores, organizes, and plays digital music

files



Table 2.3: Types of Computer Systems

Computer programs: sequences of instructions for the computer

Documentation: describes program functions

Systems software: coordinates the activities of hardware and programs

Application software: helps users solve particular problems


Sphere of influence: the scope of problems and opportunities addressed by a particular organization Personal Workgroup Enterprise



Table 2.4: Classifying Software by Type and Sphere of Influence

Controlling operations of computer hardware is one of the most critical functions of systems software

Also supports application programs’ problem-solving capabilities

Different types of systems software include:Operating systemsUtility programs


Operating system (OS): programs that control the hardware and interface with applications

Common hardware functionsGet input (e.g., keyboard)Retrieve data from disks and store data on disksDisplay information on a monitor or printer


Combinations of OSs, computers, and users:Single computer with a single userSingle computer with multiple usersMultiple computersSpecial-purpose computers



Figure 2.8: The Role of Systems Software

Activities performed by the operating systemPerform common computer hardware functionsProvide a user interface and input/output

managementProvide a degree of hardware independenceManage system memory


Activities performed by the operating system (continued)Manage processing tasksProvide networking capabilityControl access to system resourcesManage files


Common hardware functionsGet input from keyboard or some other input

deviceRetrieve data from disksStore data on disksDisplay information on a monitor or printer


User interfaceAllows individuals to access and command

the computer systemCommand-based user interface: uses

text commandsGraphical user interface (GUI): uses

icons and menus to send commands to the computer system


Hardware independenceApplication program interface (API):

allows applications to make use of the operating system

Memory managementConverts a user’s request for data or

instructions to the physical location where the data or instructions are stored



Figure 2.9: Application Program Interface Links Application Software to the Operating System

Processing tasksMultitasking: more than one program running

at the same timeTime-sharing: more than one person using a

computer system at the same timeScalability: ability to handle an increasing

number of concurrent users smoothly Networking capability: aids users in

connecting to a computer network


Operating Systems (continued)

Access to system resourcesProtection against unauthorized accessLogins and passwords

File managementEnsures that files in secondary storage are:

Available when needed Protected from access by unauthorized users



Table 2.5: Popular Operating Systems Across All Three Spheres of Influence

Microsoft PC operating systemsPC-DOS and MS-DOS: early, command-

driven OSsWindows XP: greatly improved stability and

security over previous versions of WindowsWindows XP N: for European marketWindows XP Professional X64: for

computers with newer 64-bit capabilitiesWindows XP Media Center Edition:

incorporates additional multimedia featuresVista: latest version of Windows


Apple operating systemsOften provides cutting edge tools in

graphics and music not available from Microsoft

Mac OS X Jaguar (OS X.2) Panther (OS X.3) Tiger (OS X.4): support for 64-bit computing,

Dashboard, Spotlight, etc.


LinuxDeveloped by Linus Torvalds in 1991Open-source productOnly the kernel of an OSSeveral distributions available with

capabilities/applications that form a complete OS Examples: Red Hat Linux, Caldera OpenLinux


Windows Server UNIX NetWare Red Hat Linux Mac OS X Server


z/OS MPE/iX and HP-UX Linux


Palm OS Windows Embedded Windows Mobile


Give users the ability to solve problems and perform specific tasks

Interact with systems software; systems software then directs the hardware to perform tasks


Proprietary software: unique program for a specific application, usually developed and owned by a single company

Off-the-shelf software: existing software program that can be purchased

Customized package



Figure 2.13: Types of Application Software


Table 2.6: A Comparison of Proprietary and Off-the-Shelf Software


Table 2.6: A Comparison of Proprietary and Off-the-Shelf Software (continued)

Serves the needs of an individual user Includes personal productivity software

Enables users to improve their personal effectiveness



Table 2.7: Examples of Personal Productivity Software


Table 2.7: Examples of Personal Productivity Software (continued)

Software suite: collection of single application programs packaged in a bundleMicrosoft Office: most popular general-

purpose software suiteOther general-purpose software suites:

Corel’s WordPerfect Office, Lotus SmartSuite, Sun Microsystems’s StarOffice

Integrated application packages: offer a range of capabilities for less money than software suitesExample: Microsoft Works



Table 2.8: Major Components of Leading Software Suites

Workgroup application software: support teamwork, whether people are in the same location or dispersed around the world

Groupware: software that helps groups of people work together more efficiently and effectively



Table 2.9: Ernst & Young’s “Three Cs” Rule for Groupware

Software that benefits an entire organization

Enterprise resource planning (ERP) software: programs that manage a company’s vital business operations for an entire multisite, global organization



Table 2.10: Examples of Enterprise Application Software

Used in businesses of all sizes and types to increase profits or reduce costs

Available in every industryExample: analysis to increase the cure rate for

cancer


Sets of keywords, symbols, and a system of rules for constructing statements

Allow humans to communicate instructions to be executed by a computer

Syntax: a set of rules associated with a programming language

Different languages have characteristics that make them appropriate for particular types of applications



Table 2.11: The Evolution of Programming Languages

Software issues and trends receiving increasing attentionSoftware bugsCopyrights and licensesSoftware upgradesGlobal software support


Software bug: defect in a computer program that keeps it from performing as it is designed to perform

Tips for reducing impact of software bugs include:Register all software so that you can receive

bug alerts, fixes, and patchesCheck the manual or read-me files for work-

aroundsAccess support area of the manufacturer’s

Web site for patches Install the latest software updates


Most software products are protected by law using copyright or licensing provisions In some cases, you are given unlimited use

of software on one or two computers In other cases, you pay for your usage—if

you use the software more, you pay more Some software now requires that you

register or activate it before it can be fully used


Software companies periodically revise their programs and sell new versions

Revised softwareMay offer new and valuable enhancementsMay just contain complex program code

changes that offer little in terms of additional capabilities

Software upgrades usually cost much less than the original purchase price


For large, global companies, getting adequate software support at all their locations for their standardized, companywide systems is a big challenge

Large vendors such as Sybase, IBM, and Hewlett-Packard typically contract out support for their software to local providers


Hardware: central processing unit (CPU), input and output devices, communications devices, primary storage devices, and secondary storage devices

Random access memory (RAM): temporary and volatile

Read-only memory (ROM): usually nonvolatile

Multiprocessing: simultaneous execution of two or more instructions


Sequential access: records retrieved in order

Direct access: records retrieved in any order

Computer programs: sequences of instructions for the computer

Systems software: coordinates the activities of hardware and programs

Application software: helps users solve problems


Operating system (OS): set of computer programs that control the hardware and interface with applications

Graphical user interface (GUI): uses icons and menus to send commands to the computer system

Programming languages: allow humans to communicate instructions to be executed by a computer


Chapter 2 Hardware and Software. Information system users must work closely with information system...

Documents

Transcript of Chapter 2 Hardware and Software. Information system users must work closely with information system...