Chapter 6: Input

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Chapter 6 Input Output

• Taking Charge of Computing
• Communications

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Key Questions

• 6.1 How is input and output hardware used by a
  computer system?
• 6.2 What are the three categories of input
  hardware, what devices do they include, and what
  are their features?
• 6.3 What are the two categories of output
  hardware, what devices do they include, and what
  are their features?
• 6.4 What are some examples of the future of input
  and output technology?

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I. Input Hardware

• Keyboards
• Pointing Devices
• Source Data-Entry Devices

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II. Pointing Devices

• Mice, Trackballs, Joysticks
• Mouse
• Trackball
• Pointing stick
• Touchpad
• Light Pen
• Digitizing Tablet
• Pen-Based Systems

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III. Common Hardware for Source Data-Entry

• Bar-Code Readers
• Bar codes(Universal Product Code or UPC)
• Mark-Recognition Character-Recognition
• Magnetic-ink char recognition (MICR)
• Banking industry
• Optical-mark recognition (OMR)
• Tests and examinations
• Optical-char recognition (OCR)
• Utility companies using turn-around documents
• Convert printed text to digital form

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MICR technology
Checks use magnetized ink that can be read by a
banks magnetic- ink character-recognition
equipment.
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Other Input Devices

• Scanning Devices Imaging Systems
• Flatbed image scanners
• Sheetfed image scanners
• Handheld image scanners
• Audio-Input
• Video-Input
• Digital Cameras

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Summary of input devices
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IV. Output Hardware

• Softcopy
• data that is shown on a display screen or is in
  audio or voice form
• Hardcopy
• Printed on paper, microfilm and microfiche

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V. Softcopy Display Screens

• Cathode-Ray Tubes (CRTs)
• Flat-Panel Displays
• Substances between plates
• Liquid crystal display (LCD)
• Electroluminescent (EL)
• Gas-plasma display
• Arrangements of transistors.Active-matrixbrighte
  r, sharper and .Passive-matrix need less
  power

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How a CRT works
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Display Screen

• Screen Clarity
• Resolution image sharpness
• horizontal vertical pixels 800x600, 1024x768
• Dot pitch space between adjacent pixels
• dot pitch lt .31 millimeter provide clear images
• Refresh rate
• how often the pixels are recharged
• Monochrome Versus Color Screens
• Bitmapped Displays
• Video Display Adapters

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VI. Hardcopy Output

• Impact Printers
• Print char or images by striking a mechanism
  (hammer) against an inked ribbon, leaving an
  image on paper
• Dot Matrix Printer
• Nonimpact Printers
• Laser printer
• Ink-jet printer
• Thermal printer

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Printer comparisons
cps characters per second ppm pages per
minute
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In Out

• Terminals
• Used to access another machine
• Monitor Keyboard
• Dumb no local processing power
• Intelligent CPU and RAM
• Special Purpose Point-of-sale (POS)
• Touch Screens

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Summary of output devices