Introduction to Computers

1
Introduction to Computers

• Lesson 2A

2
Keyboard

• Alphanumeric keys
• Modifier keys
• Numeric keypad
• Function keys
• Cursor-movement keys
• Special-purpose keys

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3
How the Computer Accepts Input from the Keyboard

• Keyboard controller
• Keyboard buffer
• Scan code
• Interrupt request
• Repeat rate

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4
The Mouse

• An input device that rolls around on a flat
  surface and controls the pointer

5
Examples of Mouse Maneuvers

• Pointing
• Clicking
• Double-clicking
• Dragging
• Right-clicking

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Mouse Variants

• Trackball
• Trackpad
• Integrated pointing device

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Lesson 2A

• Standard Input Devices

8
Review Questions

• What are the kinds of keys on a keyboard?
• What is a mouse?
• What are examples of mouse maneuvers?
• What are the three mouse variants?

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The Keyboard
10
From the Keyboard to the Computer
11
Keyboard

• Primary input device for entering text and numbers

12
Standard Keyboards Have Five Groups of Keys

• Alphanumeric keys
• Modifier keys
• Numeric keypad
• Function keys
• Cursor-movement keys

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13
Mouse

• An input device that rolls around on a flat
  surface and controls the pointer

14
Pointer

• Also called the mouse pointer
• An on-screen object for selecting text accessing
  menus and interacting with programs, files, or
  data

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Other Pointing Devices

• Trackball
• Trackpad, also called a touchpad
• Joystick, also called an integrated pointing
  device, 3-D point stick, or TrackPoint

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Alternative Input Devices

• Devices for the hand
• Optical devices
• Audiovisual devices

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Monitors

• Cathode ray tube (CRT)
• Flat-panel. Most common flat-panel is the liquid
  crystal display (LCD) monitor

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Pixel

• Pixel, short for picture element, is the smallest
  number of phosphor dots that the electron gun
  inside the monitor can focus on

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Two Main LCD Categories

• Passive matrix LCDuses a transistor for each row
  and column of pixels.
• Active matrix LCDuses a transistor for each
  pixel on the screen.
• Thin-film transistor displays use multiple
  transistors for each pixel.

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Other Kinds of Monitors

• Plasma/gas plasma displayCreated by sandwiching
  a special gas between two sheets of glass.

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Four Things to Consider When Monitor Shopping

• Size
• Resolution
• Refresh rate
• Dot pitch

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Video Controller

• Intermediary device between the CPU and the
  monitor
• Controls how things look on-screen

(VGA card)
23
Sound Card

• Translates digital sounds into the electric
  current that is sent to the speakers

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Printers

• Impact
• Nonimpact

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Examples of Printers

• Dot matrix
• Ink jet
• Laser

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Four Things to Consider When Printer Shopping

• Image quality, measured in dots per inch (dpi)
• Speed, measured in pages per minute (ppm)
• Initial cost
• Cost of operation