MISLectureNotes99Fal..

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MISLectureNotes99Fal..

  1. 1. Introduction to IT Hardware <ul><li>Hardware : the collection of digital devices used to input, store, process and output data </li></ul><ul><li>Choice of hardware affects choices of all other IT components and operation of entire system </li></ul><ul><li>Central processing unit (CPU): </li></ul><ul><ul><li>composed of arithmetic/logic unit (ALU), control unit, registers </li></ul></ul><ul><ul><li>associated with short-term data storage </li></ul></ul><ul><ul><li>is basis on which hardware is configured </li></ul></ul><ul><li>CPU is linked to </li></ul><ul><ul><li>Input devices </li></ul></ul><ul><ul><li>Communications devices </li></ul></ul><ul><ul><li>Output devices </li></ul></ul><ul><ul><li>Secondary storage </li></ul></ul>
  2. 2. Evaluating CPUs and Memory <ul><li>CPUs are evaluated using the concepts of machine cycle time, clock speed, and wordlength and bus line width </li></ul><ul><li>Machine cycle time : </li></ul><ul><ul><li>length of time required to execute single instruction </li></ul></ul><ul><ul><li>Expressed as microseconds (time) or millions of instructions per second (MIPS; rate) </li></ul></ul><ul><li>Clock speed : </li></ul><ul><ul><li>rate at which the CPU produces electronic pulses </li></ul></ul><ul><ul><li>based on execution of elementary instructions </li></ul></ul><ul><ul><li>Expressed as millions of cycles per second (Megaherz; MHz) </li></ul></ul><ul><li>Wordlength and bus line width </li></ul><ul><ul><li>wordlength is number of bits CPU can process at once </li></ul></ul><ul><ul><li>bus line width is amount of bits that can be transferred among components </li></ul></ul>
  3. 3. Comparing CPUs <ul><li>CPU measures of machine cycle time, clock speed and wordlength/bus line width cannot be directly compared </li></ul><ul><li>Clock speed along is insufficient for good comparisons </li></ul><ul><li>Intel Corporation has introduced Intel Comparitive Microprocessor Performance Index, or iCOMP </li></ul><ul><ul><li>iCOMP weights values of various measures </li></ul></ul><ul><ul><li>is used for for comparing Intel processors, not systems; system performance affects CPU performance </li></ul></ul><ul><li>CPU empirical principles </li></ul><ul><ul><li>All else equal, more clock speed is preferable to less </li></ul></ul><ul><ul><li>CPU speed always increases due to increase in transistor densities (Moore’s Law) </li></ul></ul>
  4. 4. Memory Characteristics <ul><li>Memory associated with CPU measured in thousands, millions, etc. of bytes ( KB , MB …) of storage capacity </li></ul><ul><li>Memory types : </li></ul><ul><ul><li>volatile random access memory (RAM), data that disappears when the system is powered down </li></ul></ul><ul><ul><li>non-volatile read-only memory (ROM), providing permanent storage for data and instructions that do not change over time </li></ul></ul><ul><ul><li>Cache memory, high-speed memory providing access to frequently used data </li></ul></ul><ul><li>Secondary storage represents permanent storage of greater volumes of data than available in main storage: </li></ul><ul><ul><li>Magnetic tapes </li></ul></ul><ul><ul><li>Magnetic disks (incl. RAID) </li></ul></ul><ul><ul><li>Optical disks </li></ul></ul><ul><ul><li>Digital video disk (DVD) </li></ul></ul><ul><ul><li>Removable storage </li></ul></ul>
  5. 5. Input Devices <ul><li>Input devices provide data and instructions to the computer. </li></ul><ul><li>Management issues associated with input devices include: </li></ul><ul><ul><li>is input data human-readable, or machine-readable, or both? </li></ul></ul><ul><ul><li>Can data entry and data input be done on-line and instantly? </li></ul></ul><ul><ul><li>Can input data be modified? </li></ul></ul><ul><li>Types of input devices include: </li></ul><ul><ul><li>keyboard and mouse </li></ul></ul><ul><ul><li>voice-recognition devices </li></ul></ul><ul><ul><li>digital computer cameras </li></ul></ul><ul><ul><li>terminals </li></ul></ul><ul><ul><li>scanning devices </li></ul></ul><ul><ul><li>optical data readers </li></ul></ul><ul><ul><li>magnetic ink character recognition (MICR) devices </li></ul></ul><ul><ul><li>automatic teller machine (ATM) devices </li></ul></ul><ul><ul><li>bar code scanners </li></ul></ul>
  6. 6. Output Devices <ul><li>Output devices are intended to provide information to decision-makers or to other information systems </li></ul><ul><li>Types of output devices: </li></ul><ul><ul><li>cathode-ray tube (CRT) display monitor </li></ul></ul><ul><ul><li>liquid-crystal display (LCD) display monitors </li></ul></ul><ul><ul><li>printers and plotters </li></ul></ul><ul><ul><li>computer output microfilm (COM) devices </li></ul></ul><ul><ul><li>speakers </li></ul></ul><ul><ul><li>multifunction devices </li></ul></ul>Choosing the right mix of input and output devices can mean the difference between an IS that is implemented successfully or not
  7. 7. Computer Systems <ul><li>Computer systems are the collection of CPU type, memory, input and output devices </li></ul><ul><li>Computer systems can be classified in the following way: </li></ul>
  8. 8. Introduction to IT Software <ul><li>Computer software (programs) provide sequences of instructions to control operations of computer hardware: </li></ul><ul><ul><li>Software can comprise 75% or more of the total cost of an IS </li></ul></ul><ul><ul><li>Expense of software due to developer salaries, increasingly complex requirements and reductions of hardware costs </li></ul></ul><ul><li>Computer software can be divided into two categories: </li></ul><ul><ul><li>systems software , which coordinates activities of hardware and various programs. Combination of systems software and hardware configuration is called the computer system platform </li></ul></ul><ul><ul><li>application software , which help users solve particular computing problems of importance to individual, group or enterprise. </li></ul></ul>
  9. 9. Management Issues in Software Use <ul><li>One way to classify software is by the portion of the organization affected by use of the software, or sphere of influence </li></ul><ul><ul><li>personal : software addresses needs of individual user </li></ul></ul><ul><ul><li>workgroup : two or more people who work together to achieve common goal </li></ul></ul><ul><ul><li>enterprise : firm or company </li></ul></ul><ul><li>Use of software had brought about issues that previously were addressed in an organization-by-organization basis: </li></ul><ul><ul><li>software licensing : copyright protection and patent laws </li></ul></ul><ul><ul><li>software upgrades : purchase/no purchase decision, distributing changes </li></ul></ul><ul><ul><li>software support : outsourcing, free vs. pay, medium by which help delivered </li></ul></ul>
  10. 10. Systems Software <ul><li>Operating systems typically execute a variety or tasks: </li></ul><ul><ul><li>Providing common computer hardware functions </li></ul></ul><ul><ul><li>Providing a user interface </li></ul></ul><ul><ul><li>Managing system memory </li></ul></ul><ul><ul><li>Controlling access to system resources </li></ul></ul><ul><li>Operating systems act as a buffer between application programs and computer hardware </li></ul><ul><li>Common features of operating systems: </li></ul><ul><ul><li>graphical user interface </li></ul></ul><ul><ul><li>hardware independence </li></ul></ul><ul><ul><li>multitasking/multithreading </li></ul></ul><ul><ul><li>time-sharing </li></ul></ul><ul><ul><li>scalability </li></ul></ul><ul><ul><li>networking capability </li></ul></ul>
  11. 11. Popular Operating Systems <ul><li>MS-DOS </li></ul><ul><ul><li>single-user, single-task system </li></ul></ul><ul><ul><li>requires specialized knowledge of command syntax </li></ul></ul><ul><ul><li>limited memory management </li></ul></ul><ul><li>DOS with Windows </li></ul><ul><ul><li>actually a shell that sits atop MS-DOS </li></ul></ul><ul><ul><li>graphical user interface, some multitasking capabilities </li></ul></ul><ul><ul><li>developed in response to Apple Macintosh OS </li></ul></ul><ul><li>OS/2 </li></ul><ul><ul><li>true multitasking/multithreading capability </li></ul></ul><ul><ul><li>significant memory requirements </li></ul></ul><ul><ul><li>lack of consumer applications written for OS/2 </li></ul></ul>
  12. 12. Popular Operating Systems (cont’d) <ul><li>Windows 95 </li></ul><ul><ul><li>true 32-bit, multitasking, multithreading OS </li></ul></ul><ul><ul><li>vulnerable to “misbehaving” 16-bit applications </li></ul></ul><ul><ul><li>uses desktop metaphor </li></ul></ul><ul><ul><li>solidified Microsoft position as pre-eminent supplier of PC OS </li></ul></ul><ul><li>Mac OS 8.1 </li></ul><ul><ul><li>Intended to run on Motorola PowerPC processors </li></ul></ul><ul><ul><li>dominant in education, publishing and graphic arts </li></ul></ul><ul><ul><li>supports novice through expert user with variable user environment </li></ul></ul><ul><li>Windows NT 5.0 </li></ul><ul><ul><li>designed to run on multiple hardware platforms </li></ul></ul><ul><ul><li>centralized security system </li></ul></ul><ul><ul><li>represents strategic direction of all Microsoft OSs </li></ul></ul>
  13. 13. Popular Operating Systems (cont’d) <ul><li>Unix </li></ul><ul><ul><li>OS of choice for large database applications and application servers </li></ul></ul><ul><ul><li>Arcane, text-based user interface supplanted by Motif/X-Windows GUI </li></ul></ul><ul><ul><li>platform independent </li></ul></ul><ul><li>What OS is right for your organization? Try to account for: </li></ul><ul><ul><li>OS market share </li></ul></ul><ul><ul><li>networking capabilities </li></ul></ul><ul><ul><li>type of application programs used </li></ul></ul><ul><ul><li>ease of use </li></ul></ul><ul><ul><li>OS management requirements </li></ul></ul><ul><li>Utility programs are used to enable an OS to run more efficiently and safely : </li></ul><ul><ul><li>anti-virus protection </li></ul></ul><ul><ul><li>diagnosing hardware problems </li></ul></ul><ul><ul><li>security management </li></ul></ul><ul><ul><li>automated data backup </li></ul></ul>
  14. 14. Application Software <ul><li>Application software are programs that help individuals, workgroups and organizations become more productive and meet organization goals </li></ul><ul><li>Types of application software: </li></ul><ul><ul><li>Pros Cons </li></ul></ul><ul><ul><li>proprietary </li></ul></ul><ul><ul><li>off-the-shelf </li></ul></ul><ul><li>Personal application software: </li></ul><ul><ul><li>word processing </li></ul></ul><ul><ul><li>spreadsheet analysis </li></ul></ul><ul><ul><li>databases </li></ul></ul><ul><ul><li>graphics programs </li></ul></ul><ul><ul><li>on-line information services </li></ul></ul><ul><ul><li>software suites </li></ul></ul>
  15. 15. Workgroup/Enterprise Application Software <ul><li>Groupware is software that enables persons to work more efficiently together </li></ul><ul><li>Types of groupware: </li></ul><ul><ul><li>Lotus Notes </li></ul></ul><ul><ul><li>Group scheduling/project management </li></ul></ul><ul><li>Three C’s of groupware: convenient, content, coverage </li></ul><ul><li>Enterprise application software address problems common to a whole organization: </li></ul><ul><ul><li>accounts receivable </li></ul></ul><ul><ul><li>general ledger </li></ul></ul><ul><ul><li>shipping </li></ul></ul><ul><ul><li>payroll </li></ul></ul><ul><ul><li>enterprise resource planning </li></ul></ul>
  16. 16. Software Development <ul><li>Programming languages are coding schemes that provide instructions to the computer system to perform a processing activity </li></ul><ul><li>Programming languages have evolved over time: </li></ul><ul><ul><li>First-generation languages: machine languages </li></ul></ul><ul><ul><li>Second-generation languages: assembly language </li></ul></ul><ul><ul><li>Third-generation languages: use of symbolic code, hardware-independent (Cobol, C, Pascal, Basic) </li></ul></ul><ul><ul><li>Fourth-generation languages: more visual, less procedural, focus on intended outputs (Access, Visual Basic, SQL) </li></ul></ul><ul><ul><li>Object-oriented languages: tie data and procedures into objects, enable reusability and modularity (Smalltalk, C++, Java) </li></ul></ul><ul><ul><li>Fifth-generation languages: visual programming, reuse management to enable knowledge-based applications (Java Studio/Java Beans) </li></ul></ul>
  17. 17. The Internet <ul><li>The Internet is a worldwide collection of interconnected networks; estimated 200,000 networks and 100 million computers </li></ul><ul><li>The Internet works by transmitting data from one computer (a host) to another using: </li></ul><ul><ul><li>the Internet Protocol (IP) and Transport Control Protocol (TCP) </li></ul></ul><ul><ul><li>Uniform Resource Locater (URL) </li></ul></ul><ul><li>Host URLs follow this convention: </li></ul><ul><ul><li>Foreign hosts end URL with country abbreviation </li></ul></ul><ul><ul><li>U.S. hosts end URL with affiliation ID, e.g. .arts, .com, .mil, .org </li></ul></ul><ul><li>The Internet can be accessed by: </li></ul><ul><ul><li>LAN server </li></ul></ul><ul><ul><li>SLIP/PPP </li></ul></ul><ul><ul><li>On-line service </li></ul></ul><ul><ul><li>Internet service provider </li></ul></ul>
  18. 18. Internet Services <ul><li>E-mail : send messages to remote users incorporting sound, graphics, hyperlinks as well as plain text </li></ul><ul><li>Telnet and FTP : log in to remote computers to transfer files </li></ul><ul><li>Usenet and Newsgroups : follow threaded discussions stored on host computers on a variety of subjects </li></ul><ul><li>Internet Phone/Videoconferencing : route phone calls and faxes over same network used to transfer data, bypassing phone company </li></ul><ul><li>Content streaming : method to transfer multimedia files over the Internet so that voice and pictures are aligned </li></ul>
  19. 19. The World Wide Web <ul><li>Originally conceived as a document management system, has evolved to thousands of Web servers that allow access to specialized documents that store text, data, images and sound </li></ul><ul><li>A Web site is a collection of files designed to allow the user access to various files (Web pages) in a predefined order </li></ul><ul><li>A Web browser is an application that translates specialized commands (HTML) with which Web pages are created into a graphical interface </li></ul><ul><li>Search engines are tools that allow users to quickly scan the internet for Web pages that satisfy certain criteria </li></ul><ul><li>Java is a programming language that enables applications residing on a Web page to be run on the user’s computer </li></ul>The Web is revolutionizing many business, non-profit and personal activities by enabling universal connectivity

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