1 / 69

Chapter 7 Input/Output Technology

Chapter 7 Input/Output Technology. Chapter 7. Systems Architecture. Chapter Goals. Describe manual input devices and how they are implemented. Explain the characteristics and implementation technology of video display devices. Understand printer characteristics and technology. Chapter 7.

kynan
Télécharger la présentation

Chapter 7 Input/Output Technology

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript


  1. Chapter 7Input/Output Technology

  2. Chapter 7 Systems Architecture Chapter Goals • Describe manual input devices and how they are implemented. • Explain the characteristics and implementation technology of video display devices. • Understand printer characteristics and technology.

  3. Chapter 7 Systems Architecture Chapter Goals • Identify the characteristics of audio I/O devices, and explain how they operate.

  4. Chapter 7 Systems Architecture Chapter Topics • Describes the concepts, technology and hardware used in communication between people and computers. • Understand the importance of I/O technology.

  5. Chapter 7 Systems Architecture Chapter Topics

  6. Chapter 7 Systems Architecture Manual Input Devices • Keyboard Input • Pointing Devices

  7. Chapter 7 Systems Architecture Manual Input Devices Keyboard Input • Keyboard devices translate keystrokes directly into electrical signals. • A keyboard controller is used to generate bit stream outputs. • The controller generates a bit stream output according to an internal program or lookup table.

  8. Chapter 7 Systems Architecture Manual Input Devices Keyboard Input • A keyboard controller generates an output called a scan code. • A scan code is a one or two-byte data element that represents a specific keyboard element.

  9. Chapter 7 Systems Architecture Manual Input Devices Pointing Devices • Mouse • Trackball • Joystick • Digitizer Tablet

  10. Chapter 7 Systems Architecture Manual Input Devices Pointing Devices Translates the spatial position of a pointer, stylus, or other selection device into numeric values within a system of two-dimensional coordinates.

  11. Chapter 7 Systems Architecture Manual Input Devices Mouse – a pointing device that is moved on a flat surface such as a table, desk or rubber pad. Trackball – a mouse with the roller ball on the top. The roller ball is moved by the fingertips, thumb or palm of the hand.

  12. Chapter 7 Systems Architecture Manual Input Devices Joystick – used as an input device with computer games. Digitizer Tablet – uses a pen, or stylus, and a digitizing tablet. The tablet is sensitive to the placement of the stylus at any point on its surface.

  13. Chapter 7 Systems Architecture Basic Concepts of Print and Display • Matrix-Oriented Image Composition • Fonts • Color • Pixel Content • Image Storage Requirements • Image Description Languages

  14. Chapter 7 Systems Architecture Basic Concepts of Print and Display Matrix-Oriented Image Composition • Display surfaces can be divided into rows and columns similar to a large table or matrix. • Each cell in the table represents one component of the image.

  15. Chapter 7 Systems Architecture Basic Concepts of Print and Display Matrix-Oriented Image Composition • One of the cells is a pixel. • The resolution of the display is the number of pixels displayed per linear measurement unit. • Resolution is stated in dots per inch(dpi).

  16. Chapter 7 Systems Architecture Basic Concepts of Print and Display

  17. Chapter 7 Systems Architecture Basic Concepts of Print and Display • Font – a collection of characters of similar style and appearance.

  18. Chapter 7 Systems Architecture Basic Concepts of Print and Display

  19. Chapter 7 Systems Architecture Basic Concepts of Print and Display

  20. Chapter 7 Systems Architecture Basic Concepts of Print and Display Color • For video displays, color is generated directly by the display device. • The video display industry has used red, green and blue as primary colors. • A video display that generates color uses mixtures or these colors.

  21. Chapter 7 Systems Architecture Basic Concepts of Print and Display Color • For print, color is light frequency reflected from the paper. • The printing industry generates color using the inverse of the primary video display colors. (subtractive color)

  22. Chapter 7 Systems Architecture Basic Concepts of Print and Display Pixel Content • Pixel content must be described numerically. • A stored set of numeric pixel descriptions is called a bit map. • A palette is a table of colors. • Color can also be produced using dithering.

  23. Chapter 7 Systems Architecture Basic Concepts of Print and Display

  24. Chapter 7 Systems Architecture Basic Concepts of Print and Display Image Storage Requirements • Image storage requirements apply to images stored in primary and secondary storage, and to buffers used in I/O devices. • Image storage requirements can be reduced with image compression techniques.

  25. Chapter 7 Systems Architecture Basic Concepts of Print and Display Image Storage Requirements Compression Techniques: • Graphics Interchange Format (GIF) • Joint Photographic Experts Group (JPEG) • Moving Pictures Experts Group (MPEG)

  26. Chapter 7 Systems Architecture Basic Concepts of Print and Display Image Description Languages • Use a symbolic language to describe primitive image components. • Can use a vector list . • Describe the image components that are straight-line segments or can be built from segments.

  27. Chapter 7 Systems Architecture Basic Concepts of Print and Display

  28. Chapter 7 Systems Architecture Technology Focus - Postscript

  29. Chapter 7 Systems Architecture Technology Focus - Postscript

  30. Chapter 7 Systems Architecture Video Display • Character-Oriented Video Display Terminals • Graphic Video Display Devices • CRTs • Flat Panel Displays

  31. Chapter 7 Systems Architecture Video Displays Character-Oriented Video Display Terminals • Commonly used during 1970s and 1980s. • Terminal – consist of an integrated keyboard and television screen. • Used today primarily in systems such as retail checkout counters and factory floor environments.

  32. Chapter 7 Systems Architecture Video Display

  33. Chapter 7 Systems Architecture Video Display Graphic Video Display Devices • Used for displaying diagrams such as construction blueprints, wireframe models, writing diagrams and to produce mathematical graphs. • By the mid-1980s monitors were manufactured.

  34. Chapter 7 Systems Architecture Video Display • Monitors operate as independent devices under control of a video controller attached to the system bus.

  35. Chapter 7 Systems Architecture Video Display

  36. Chapter 7 Systems Architecture Video Display CRT • Current monitors are implemented using cathode ray tubes. • A CRT is an enclosed tube. • An electron gun in the rear of the tube generates a stream of electrons. • Pixel illumination is controlled by pulsing the electron beam.

  37. Chapter 7 Systems Architecture Video Display • The number of times per second that the entire surface is scanned by the electron gun is called the refresh rate.

  38. Chapter 7 Systems Architecture Video Display Flat Panel Display • Liquid Crystal Display – is a flat panel matrix that consists of encapsulated liquid crystals sandwiched between two polarizing panels. • Passive Active Matrix Display – shares transistors among rows and columns of pixels.

  39. Chapter 7 Systems Architecture Video Display • Electroluminescent Displays – similar to construction of LCDs. Color is generated with three matrices of different colored phosphors.

  40. Chapter 7 Systems Architecture Printers and Plotters • Dot Matrix Printers • Ink-Jet Printers • Laser Printers • Plotters

  41. Chapter 7 Systems Architecture Printers and Plotters

  42. Chapter 7 Systems Architecture Printers and Plotters Dot Matrix Printers • Generate images through mechanical contact with ink and papers. • Character codes received by the print generator are transmitted as a series of control commands to the print head. • Characters are generated one or two vertical rows at a time.

  43. Chapter 7 Systems Architecture Printers and Plotters Ink-Jet Printers • Uses a paper movement mechanism similar to that of a dot matrix printer. • The print head of an ink-jet printer consists of an ink cartridge, a set of ink chambers and a set of ink nozzles.

  44. Chapter 7 Systems Architecture Printers and Plotters Ink-Jet Printers • Each ink nozzle can print a single pixel and nozzles are arranged in short vertical rows similar to those of a dot matrix printer.

  45. Chapter 7 Systems Architecture Printers and Plotters Laser Printers • Operates differently from other types of printers. • No print head or ink ribbon is used. • An internal image of the entire page is stored in an internal buffer as a bit map. • Once filled, the buffer contents are sent to the print driver for generation.

  46. Chapter 7 Systems Architecture Printers and Buffers

  47. Chapter 7 Systems Architecture Printers and Plotters Plotters • A printer that generates line drawings on wide sheets or rolls of paper. • Paper is mounted within a paper control mechanism that can move the paper up or down precisely. • Can handle paper widths up to 60 inches.

  48. Chapter 7 Systems Architecture Optical Input Devices Optical scanning devices can be differentiated by the following criteria: • Input format requirements • Normal and maximum spatial resolution • Normal and maximum chromatic resolution • Embedded processing capacity

  49. Chapter 7 Systems Architecture Optical Input Devices Mark Sensors and Bar Code Scanners • Mark Sensors – scans for light or dark marks at specific locations on a page. • The mark sensors uses preprinted bars on the edge of the page to establish reference points.

  50. Chapter 7 Systems Architecture Optical Input Devices Mark Sensors and Bar Code Scanners • A scanning laser sweeps a narrow laser beam back and forth across the bar code. • Bars must have precise width and spacing, as well as high contrast for accurate decoding.

More Related