Principles of Information Systems textbook: Principles of Information Systems, Sixth Edition. Dr.Amer Alzaidi Department of Information Systems

Transcription

1 + Principles of Information Systems textbook: Principles of Information Systems, Sixth Edition Dr.Amer Alzaidi Department of Information Systems

2 Fundamentals of Information Systems, Sixth Edition Chapter 2 Hardware and Software

3 Why Learn About Hardware and Software? Organizations invest in computer hardware to: Improve worker productivity Increase revenue, reduce costs Provide better customer service Managers: Are expected to know enough about their business needs to be able to ask tough questions

4 Computer Systems: Integrating the Power of Technology To assemble an effective and efficient system: You should select and organize components while understanding the trade-offs between overall system performance and cost, control, and complexity Hardware objectives are: Subordinate to, but supportive of, the information system and the current and future needs of the organization

5 Hardware Components Central processing unit (CPU): Arithmetic/logic unit, the control unit, and the register areas Arithmetic/logic unit (ALU): Performs mathematical calculations and makes logical comparisons Control unit: Sequentially accesses program instructions, decodes them, and coordinates the flow of data in and out of the ALU, registers, primary storage, and even secondary storage and various output devices

6 Hardware Components (continued)

7 Processing and Memory Devices: Power, Speed, and Capacity System unit: Houses 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

8 Processing Characteristics and Clock speed: Functions Series of electronic pulses produced at a predetermined rate that affects machine cycle time Often measured in: Megahertz (MHz): millions of cycles per second Gigahertz (GHz): billions of cycles per second Physical characteristics of the CPU Most CPUs are collections of digital circuits imprinted on silicon wafers, or chips, each no bigger than the tip of a pencil eraser

9 Memory Characteristics and Functions Memory: Provides the CPU with a working storage area for programs and data Rapidly provides data and instructions to the CPU Storage capacity: Eight bits together form a byte (B)

10 Memory Characteristics and Functions (continued)

11 Memory Characteristics and Functions Types of memory: (continued) Random access memory (RAM): Temporary and volatile Read-only memory (ROM): Nonvolatile Provides permanent storage for data and instructions that do not change

12 Multiprocessing Multiprocessing: Simultaneous execution of two or more instructions at the same time Multicore microprocessor: Combines two or more independent processors into a single computer

13 Multiprocessing (continued) Parallel computing: Simultaneous execution of the same task on multiple processors to obtain results faster Grid computing: Use of a collection of computers to work in a coordinated manner to solve a common problem

14 Secondary Storage and Input and Secondary storage: Output Devices Compared with memory, offers the advantages of nonvolatility, greater capacity, and greater economy Considerably slower than memory

15 Access Methods Sequential access: Data must be retrieved in the order in which it is stored Devices used called sequential access storage devices (SASDs) Direct access: Records can be retrieved in any order Devices used are called direct access storage devices (DASDs)

16 Secondary Storage Devices Magnetic tapes: Primarily for storing backups of critical organizational data Magnetic disks: Direct-access storage device Redundant array of independent/inexpensive disks (RAID): Method of storing data that generates extra bits of data from existing data Virtual tape: Storage technology for less frequently needed data

17 Secondary Storage Devices Storage area network: (continued) Uses computer servers, distributed storage devices, and networks to tie everything together Optical discs: Common form of optical disc on which data cannot be modified once it has been recorded Digital video disc (DVD): Storage medium used to store software, video games, and movies

18 Secondary Storage Devices (continued) Solid state secondary storage devices: Store data in memory chips rather than magnetic or optical media Have few moving parts, so they are less fragile than hard disk drives Disadvantages of SSD: High cost per GB of data storage Lower capacity compared to current hard drives

19 Input Devices Devices used to input general types of data: Personal computer input devices Speech recognition technology Digital cameras Touch-sensitive screens Optical data readers Magnetic ink character recognition (MICR) devices Pen input devices Magnetic stripe card Radio Frequency Identification

20 Input Devices (continued)

21 Display monitors: Output Devices Used to display the output from the computer Plasma display: Uses thousands of smart cells (pixels) consisting of electrodes and neon and xenon gases that are electrically turned into plasma to emit light LCD displays: Flat displays that use liquid crystals Organic light-emitting diodes (OLEDs): Use a layer of organic material sandwiched between two conductors

22 Output Devices (continued) Printers and plotters: Two main types of printers are laser printers and inkjet printers Plotters are a type of hard-copy output device used for general design work Digital audio player: Can store, organize, and play digital music files E-books: Digital media equivalent of a conventional printed book

23 Computer System Types Computer systems: Can range from desktop (or smaller) portable computers to massive supercomputers that require housing in large rooms

24 Computer System Types (continued)

25 Computer System Types (continued)

26 Handheld computers: Portable Computers Single-user computers that provide ease of portability because of their small size Laptop computer: Personal computer designed for use by mobile users Notebook computers: Lightweight computer that weighs less than 5 pounds

27 Portable Computers (continued) Netbook computer: The smallest, lightest, least expensive member of the laptop computer family Tablet computers: Portable, lightweight computers with no keyboard Smartphone: Combines the functionality of a mobile phone, camera, Web browser, tool, MP3 player, and other devices

28 Nonportable Single-User Computers Thin client: Low-cost, centrally managed computer with no extra drives Desktop computers: Single-user computer systems that are highly versatile

29 Nonportable Single-User Computers Nettop computer: (continued) Inexpensive desktop computer designed to be smaller, lighter, and consume much less power than a traditional desktop computer Workstations: More powerful than personal computers but still small enough to fit on a desktop

30 Multiple-User Computer Systems Server: Used by many users to perform a specific task, such as running network or Internet applications Blade server: Houses many computer motherboards The approach requires much less physical space than traditional server farms

31 Multiple-User Computer Systems Mainframe computer: (continued) Large, powerful computer shared by hundreds of concurrent users connected to the machine over a network Supercomputers: The most powerful computers with the fastest processing speed and highest performance

32 Green Computing Concerned with: Efficient and environmentally responsible design, manufacture, operation, and disposal of IS-related products Goals: Reduce the use of hazardous material Enable companies to lower their power-related costs Enable the safe disposal or recycling of some 700,000 tons of computers each year

33 Overview of Software Computer programs: Sequences of instructions for the computer Documentation: Describes program functions to help the user operate the computer system Types of software: Systems software Application software

34 Supporting Individual, Group, and Sphere of influence: Organizational Goals Scope of problems and opportunities addressed by a particular organization Personal sphere of influence: Serve the needs of an individual user Personal productivity software: Helps users improve their personal effectiveness Workgroup: When two or more people work together to achieve a common goal

35 Supporting Individual, Group, and Organizational Goals (continued) Workgroup sphere of influence: Serves the needs of a workgroup Enterprise sphere of influence: Supports the firm in its interaction with its environment

36 Installing and Removing New Software Before you can use any type of software, it must be installed on a computer Software for personal computers typically comes on CDs or is downloaded from the Web

37 Systems Software Includes: Operating systems Utility programs

38 Operating Systems Set of programs that controls computer hardware and acts as an interface with application programs Can control one computer or multiple computers, or Can allow multiple users to interact with one computer Combinations of OSs, computers, and users: Single computer with a single user Single computer with multiple users Multiple computers with multiple users Special-purpose computers

39 Operating Systems (continued)

40 Operating Systems (continued) Activities performed by the operating system: Perform common computer hardware functions Provide a user interface and input/output management Provide a degree of hardware independence Manage system memory Manage processing tasks Provide networking capability Control access to system resources Manage files

41 Operating Systems (continued) Common hardware functions: Get input from keyboard or another input device Retrieve data from disks Store data on disks Display information on a monitor or printer

42 Operating Systems (continued) User interface and input/output management: User interface: Allows individuals to access and command the computer system Command-based user interface: Requires that text commands be given to the computer to perform basic activities Graphical user interface (GUI): Uses icons and menus displayed on screen to send commands to the computer system

43 Operating Systems (continued) Hardware independence: Application program interface (API): Allows applications to make use of the operating system Memory management: Allows computer to execute program instructions effectively and to speed processing

44 Operating Systems (continued)

45 Operating Systems (continued) Processing tasks: Multitasking: More than one program can run at the same time Time-sharing: Allows more than one person to use a computer system at the same time Scalability: Ability of the computer to handle an increasing number of concurrent users smoothly

46 Operating Systems (continued) Networking capability: Allows computers in a network to send and receive data and share computing resources Access to system resources and security: Protection against unauthorized access OS establishes a logon procedure File management: Ensures that files in secondary storage are available when needed and that they are protected from access by unauthorized users

47 Current Operating Systems Microsoft PC operating systems: Windows XP Windows Vista Windows 7 Apple computer operating systems: Wintel Snow Leopard (OS X v10.6) Linux: Red Hat Linux Caldera OpenLinux

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49 Workgroup Operating Systems Windows Server: Can be used to prevent unauthorized disclosure of information UNIX: Can be used on many computer system types and platforms Red Hat Linux: Can manage a cluster of up to eight servers Mac OS X Server: Includes support for 64-bit processing

50 Enterprise Operating Systems z/os: IBM s first 64-bit enterprise OS HP-UX and Linux: HP-UX: Robust UNIX-based OS from Hewlett-Packard Supports Internet, database, and business applications on server and mainframe enterprise systems

51 Operating Systems for Small Computers, Embedded Computers, and Special-Purpose Devices Cell phone embedded systems and operating systems: Embedded systems provide communication and limited personal information management services Windows embedded: Included with or embedded into small computer devices Proprietary Linux-based systems: Linux is a major competitor to Symbian

52 Utility Programs Help to perform maintenance or correct problems with a computer system Some can help computer systems run better and longer without problems Can help to secure and safeguard data

53 Utility Programs (continued)

54 Application Software Application programs: Interact with systems software Help you perform common tasks, such as: Creating and formatting text documents Performing calculations Managing information

55 Types and Functions of Application Proprietary software: Software One-of-a-kind program for a specific application, usually developed and owned by a single company Off-the-shelf software: Existing software program that is purchased Application service provider (ASP): Company that can provide software, support, and computer hardware on which to run the software from the user s facilities over a network

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57 Overview of Application Software (continued) Software as a service (SaaS): Allows businesses to subscribe to Web-delivered business application software by paying a monthly service charge or a per-use fee Can reduce expenses by sharing its running applications among many businesses Cloud computing: Use of computing resources on the Internet (the cloud) rather than on local computers

58 Personal Application Software Word processing Spreadsheet analysis Database applications Graphics program Personal information managers Software suites and integrated software packages

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60 Mobile Application Software Operating systems designed for smartphones include: OS X iphone, Android, and WebOS Tens of thousands of applications have been: Developed by third parties for the iphone Palm WebOS: Has only recently released its software development kit

61 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 effectively

62 Workgroup Application Software (continued)

63 Enterprise Application Software Software that benefits an entire organization Enterprise resource planning (ERP) software: Set of integrated programs that manage a company s vital business operations for an entire multisite, global organization

64 Application Software for Information, Decision Support, and Specialized Purposes Available in every industry: Specialized application software for information, decision support, and other purposes

65 Programming Languages Sets of keywords, symbols, and a system of rules for constructing statements: By which humans can communicate instructions to be executed by a computer Programming: Involves translating what a user wants to accomplish into instructions that the computer can understand and execute

66 Software Issues and Trends Software bug: Defect in a program that keeps it from performing as it should Some tips for reducing impact of software bugs: Register all software Check read-me files for workarounds Access support area of the manufacturer s Web site for patches Install latest software updates

67 Copyrights and Licenses 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

68 Software Upgrades When software companies stop supporting older software versions or releases: Some customers feel forced to upgrade to the newer software Deciding whether to purchase the newest software: Can be a problem for corporations and people with a large investment in software

69 Global Software Support Supporting local operations: One of the biggest challenges IS teams face when putting together standardized, company-wide systems Trend: Outsourcing global support to one or more thirdparty distributors

70 Summary Hardware: The physical components of a computer that perform the input, processing, storage, and output activities of the computer Green computing: Concerned with the efficient and environmentally responsible design, manufacture, operation, and disposal of IS-related products Software: Consists of programs that control the workings of the computer hardware

71 Summary (continued) Operating system (OS): Set of computer programs that controls the computer hardware to support users computing needs Manages tasks to allocate computer resources through multitasking and time-sharing Application software: Applies the power of the computer to solve problems and perform specific tasks