Input and Output: The User Connection

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Chapter 5

• Input and Output The User Connection

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Input vs. Output

• Users use input devices to provide data to the
  computer
• Output devices provide information to the user

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Input devices

• Keyboard
• Function keys
• Main keyboard
• Shift, control, Caps lock, tab
• Numeric keys and status lights
• Num lock
• Num lock, Insert, and Caps lock are toggle keys

4
Input DevicesPointing Device

• Pointer
• Arrow
• Insertion point or cursor
• Vertical bar

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Input DevicesPointing Device

• Mouse
• Mechanical mouse
• Optical mouse
• Wireless mouse

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Input DevicesPointing Device

• Trackball

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Input DevicesPointing Device

• Touchpad

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Input DevicesPointing Device

• Pointing stick

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Input DevicesPointing Device

• Joystick
• Used often for games
• Can be used instead of a mouse

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Input DevicesPointing Device

• Graphics tablet
• Stylus
• Puck

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Input DevicesPointing Device

• Touch screens
• Used in kiosks, a self-contained station
• Kiosks are found in libraries, museums, airports,
  and shopping malls

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Input DevicesPointing Device

• Pen-based computing

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Magnetic-Ink Character Recognition (MICR)

• A type of source data automation
• Used most by the banking industry
• MICR numbers printed on checks

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SCANNERS

• Use laser light
• 3 types
• Flatbed scanner
• Sheetfed scanner
• Handheld scanner

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SCANNERS (Extra)

• Flatbed scanner
• Scans one sheet at a time
• Can be used on books
• Can scan 3-D objects
• Take a lot of desk space

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SCANNERS (Extra)

• Sheetfed scanner
• Scans one sheet at a time
• Cannot scan bound material
• Take less space than flatbed

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SCANNERS (Extra)

• Handheld scanner
• Least expensive
• Least accurate
• May require several passes to get a complete page
  scanned in

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Optical Recognition

• Optical Mark Recognition (OMR)
• For reading marks, lines, filled circles, etc
• Optical Character Recognition (OCR)
• Analyzes an image, converts it into characters
• Can recognize handwritten characters if done in
  block printing

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Optical Recognition

• Bar codes
• Universal Product Code (UPC) is one standard
• Other codes exist

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Voice Input

• Speech recognition
• Speaker-dependent
• trained for a specific persons voice
• Speaker-independent
• Recognize any voice
• Limited vocabulary

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Input Device

• Digital camera
• No film
• Uses memory chips, disks, or memory sticks

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Output Devices

• CRT monitor
• Cathode Ray Tube
• Raster scanning
• 3 colors of light red, green, and blue produce
  all the colors

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Output Devices

• CRT monitor quality
• Refresh rate (scan rate) number of
• Interlaced vs. non-interlaced
• Resolution
• More pixels means higher resolution
• Dot pitch
• Size of monitor

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Output Devices

• Flat Panel screen
• Liquid crystal display (LCD)
• Active matrix (TFT)
• Passive matrix

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Computer Output

• Monitor
• Softcopy
• Printer
• Hardcopy
• Portrait vs. landscape
• Resolution in dpi (dots per inch)

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Computer Output

• Voice output
• Speech synthesis
• Synthesis by analysis
• Synthesis by rule
• Music and sound output
• MIDI

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Computer Output

• Graphics cards provide output to a monitor
• Have memory chips on the card
• Graphics standards
• SVGA - Super Video Graphics Array
• XGA Extended Graphics Array
• XGA supports more simultaneous colors than SVGA

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Output Devices

• Dot-matrix printer
• Impact
• Pins striking a ribbon against paper
• Used for multiple part forms

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Output devices

• Laser printer
• Non-impact
• Light beam helps transfer images to paper
• High quality
• Uses toner and technology similar to a photocopier

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Output Devices

• Ink-jet printer
• Non-impact
• Spray ink onto paper
• Good quality
• Most can print in color

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Computer Terminal

• Dumb terminal
• Keyboard and monitor
• No processing capability
• Intelligent terminal
• Keyboard, monitor, memory
• Some processing capability
• Both dumb and intelligent terminals must be
  connected to a host or server computer

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Point-of-sale terminal (POS)

• Specialized input and output devices
• The cash register at a supermarket is a POS
• Input through keyboard, scale, plus one or more
  scanners
• Output to one or more display devices plus
  receipt printer