1 chapter 5 input and output: the user connection
TRANSCRIPT
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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
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Input Devices–Pointing Device
Pointer Arrow
Insertion point or cursor Vertical bar
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Input Devices–Pointing Device
Mouse Mechanical mouse Optical mouse Wireless mouse
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Input Devices–Pointing Device Trackball
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Input Devices–Pointing Device Touchpad
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Input Devices–Pointing Device Pointing stick
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Input Devices–Pointing Device Joystick
Used often for games
Can be used instead of a mouse
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Input Devices–Pointing Device Graphics tablet
Stylus Puck
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Input Devices–Pointing 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 Devices–Pointing 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 person’s 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