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C5- Input and Output, The User Connection

C5- Input and Output, The User Connection. How Users See Input and Output. Users submit data (input) to the computer to get processed information (output) Output can be instant reaction to input Also can be separated by time , distance, or both. Instant Reaction.

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C5- Input and Output, The User Connection

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  1. C5- Input and Output, The User Connection

  2. How Users See Input and Output • Users submit data (input) to the computer to get processed information (output) • Output can be instant reaction to input • Also can be separated by time, distance, or both

  3. Instant Reaction Input and Output Separated • Items scanned at supermarket • Produce item name and price at counter • Forklift operator speaks to computer • Forklift obeys operator’s commands • Sales rep enters an order on a pad • Characters displayed as “typed” text and stored in pad • Factory workers punch a time clock as they go from task to task • Produce weekly paychecks and management reports • Data on checks input into bank computer • Computer processes entries once a month to prepare statements • Charge-card transactions provide input • Processed monthly to produce customer bills • Water samples collected and input into computer • Used to produce reports that show patterns of water quality

  4. User Input: Getting Data using keyboard Pointing devices Source data automation • Similar to typewriter keyboard • May be part of a personal computer • May be part of a terminal connected to a computer in another location • Can be unique to an industry • Keys on McDonald’s keyboards represent Big Mac or large fries • Ergonomic keyboards

  5. Anatomy of a Keyboard • Designed to reduce or minimize repetitive strain injury of wrists • Provide more natural, comfortable position of wrists, arms, and hands

  6. User Input: Getting Data using Pointing Devices • Used to position a pointer on the screen • Communicate commands to operating system by clicking a button • Common devices • Mouse • Devices used for games • Devices used in laptops • Others

  7. Mouse • The most common pointing device • Movement on flat surface causes movement of pointer on screen • Several types • Mechanical - small ball on underside rolls as mouse is moved • Optical - uses a light beam to monitor mouse movement • Cordless - uses either infrared or radio waves, rather than a cord, to connect to computer

  8. Trackball and Joystick • Trackball • Variation on mechanical mouse • User rolls the ball directly • Often built into laptop computers • Joystick • Short lever with handgrip • Distance and speed of movement controls pointer’s position • Pressing trigger causes actions to take place

  9. Touchpad and Pointing Stick • Touchpad • Rectangular pressure-sensitive pad • Sliding finger across pad moves pointer • Tapping with finger recognized as click • Pointing stick • Small pressure-sensitive post mounted in center of keyboard • Pushing post in any direction moves pointer

  10. Other Pointing Devices • Graphics tablet • User moves stylus or puck across board • Used to create or trace precise drawings • Touch screen • Allow user to touch items on screen • Position of finger on screen determines item to be input into system • Used at kiosks in public places such as malls • Pen-based computing • Use pen-like stylus to input data • Often used in PDAs or pocket PCs Return

  11. User Input: Getting Data using Source Data Automation • Use of special equipment to collect data at the source • Primary areas • Magnetic-ink character recognition (MICR) • Optical recognition devices • Other sources Return

  12. MICR • Uses a machine to read characters made of magnetized particles • Banking industry is predominant user • Characters preprinted on lower left-hand side of check • Amount added by MICR inscriber when check is cashed Return

  13. Optical Recognition • Uses a light beam to scan data and convert to electrical signals • Common uses • Scanners are the most common form • Other optical recognition methods Return

  14. Common Uses Scanners • Scanners at supermarkets • Document imaging - converts paper documents to electronic versions • Documents stored on disk • Can be edited or processed by software • Flatbed scanner • Typically scans one page at a time • Can be used to scan large bound documents • Sheetfed scanner • Motorized rollers feed sheet across scanner head • Handheld scanner • Smallest and least accurate • Optical character recognition (OCR) software required to convert picture into characters

  15. Other Optical Recognition Methods • Optical Mark Recognition • Machine senses marks on piece of paper • Optical character recognition • Wand reader reads characters in special typeface • Bar Codes • A series of vertical marks • Represents a unique code • Universal Product Code (UPC) used as standard in supermarkets

  16. Voice Input Digital Camera • User speaks to computer • Speech recognition devices convert spoken words into binary digits • Most are speaker-dependent • System “learns” user’s voice • Types of systems • Discrete word systems - user must pause between words • Continuous word systems - user can speak normally • User takes photo that is stored on a chip • Photo can be downloaded to computer • Use photo-editing software to enhance • Store permanently on CDs or DVDs • Photos composed of many pixels of color • Photos stored on removable memory card Other Input Sources

  17. Video Input • Digital video consists of series of still frames • Displayed rapidly enough to give illusion of motion • Web cam used to transmit video over the Internet • Can capture video from analog sources with video capture card Other Input Sources

  18. Computer Screen Technology • Computer screens • Printers • Voice output • Music output • Microform • Screen is part of computer’s monitor • Screen output known as soft copy • Intangible and temporary • Common forms • Cathode ray tube (CRT) • Flat-panel screens • Smart displays Output: Information for the User

  19. CRT Screens Factors Affecting Performance • Display text and graphics • Most are in color • Some monochrome monitors are used in applications that have no need for color or graphics • Graphics card converts signals from the control unit into the image the user sees • Factors affecting performance • Scan rate • Image refresh rate • Resolution (clarity) of screen • Measured in pixels- more pixels, the higher the resolution • Graphics standards exist • Dot pitch • The amount of space between dots • The smaller the dot pitch, the sharper the image • Video memory • A high-speed form of RAM installed on graphics card Output: Information for the User

  20. Graphic Standards • Agree on resolutions, colors, other issues related to displaying graphics • Super Video Graphics Adapter (SVGA) is most common standard • Provides 800 (horizontal) x 600 (vertical) pixels on the display • Other varieties of SVGA exist • Support 16 million colors • The number of colors that can be displayed depends on amount of video memory

  21. Display screens • Flat-Panel Screens • LCD Technologies • Smart displays • Based on flat-panel technology • Each contains its own processor • Wireless transmitter-receiver allows user to control desktop from anywhere in the house

  22. Produce information on paper output~ hard copy • Orientation~ Portrait, Landscape • Two ways of printing • Impact printer • Nonimpact printer Printers

  23. Impact Printers Nonimpact Printers • Impact Printers • Physical contact with paper • Line printer • Used for lengthy reports • Dot-matrix printer • Has print head consisting of one or more columns of pins • Pins form characters and images as pattern of dots • Places an image on a page without physically touching the page • Laser printer • Uses light beam to help transfer images to paper • High-quality, high speed • Ink-jet printer • Sprays dots of ink from jet nozzles • Requires high-quality paper so ink does not smear • Less expensive than laser printers Impact printer and Nonimpact printer

  24. Voice Output • Voice synthesizers convert data to vocalized sounds • Two approaches • Synthesis by analysis - analyzes actual human voice, records and plays back as needed • Synthesis by rule - uses linguistic rules to create artificial speech • Used in automated telephone-based customer service applications • Useful when an inquiry would be followed by a short reply, such as a balance inquiry

  25. Music Output • Multimedia clips, games, videos include sight and sound • Speakers placed on side of monitor • Powered sub-woofers produce low-frequency sounds • Musical Instrument Digital Interface (MIDI) • Rules for connecting musical instruments, synthesizers, and computers • Allows users to set up home studios that rival capabilities of professional recording studios Return

  26. Computer Output Microform (COM) • Output of photographically reduced images on microfilm or microfiche • Microfilm - images stored on continuous roll of film • Microfiche - images stored in rows and columns on a card • Needs special reader • Common uses • Libraries store back issues of periodicals • Businesses store large volumes of historical records Return

  27. Terminals • Combine input and output capabilities • Dumb terminal • Keyboard for input and monitor for output • No processing capability • Intelligent terminal • Has limited memory and a processor • Point-of-sale (POS) terminal • Captures retail sales data when transaction takes place

  28. Business Graphics Video Graphics • A powerful way to impart information • Colorful graphics, maps, and charts help managers compare data, spot trends, and make quicker decisions • As underlying data changes, charts and graphs are instantly updated • A series of video images • Displayed rapidly to give the impression of motion • Used extensively in television • Also used in computer and arcade video games Computer-aided design/computer-aided manufacturing (CAD/CAM) Computer Graphics

  29. Computer-Aided Design/Computer-Aided Manufacturing • Creates two- and three-dimensional designs • Performs engineering tests such as stress tests • Serves as bridge between design and manufacturing

  30. Ethics and Data • Once data is in computer, there are many ways it can be used • Ethical issues to ponder • Is it ethical to use a computer to alter photographs? • Is it ethical to erase e-mail messages that may be of interest to a party in a lawsuit? • Is it ethical to use someone else’s data for your purposes?

  31. Objectives • Describe the user relationship with computer input and output • Explain how data is input into a computer system and differentiate among various input equipment • Describe how a monitor works and the characteristics that determine quality • List and describe the different methods of computer output • Differentiate among different kinds of printers • Explain the function of a computer terminal and describe the types of terminals • Describe the ethical considerations involved in handling computer data

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