Teachers Discovering Computers
Integrating Technology and
Digital Media in the Classroom
7th Edition
Chapter 4
Hardware for Educators
Chapter Objectives
 Describe the system unit
 Define the term bit and describe how a series of
bits are used to represent data
 Identify the major components of the system unit
and explain their functions
 Explain how the CPU uses the four steps of a
machine cycle to process data
 Describe the four types of input as well as input
devices and pointing devices
 List the characteristics of a keyboard and identify
various types of keyboards
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Chapter Objectives
 Differentiate among the four types of output
 Identify different types of output devices
 Explain differences among various types of
printers
 Differentiate between storage and memory
 Identify types of storage media and devices
 Differentiate between CDs, DVDs, and BDs
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The System Unit
 System unit
 Boxlike case that houses
the electronic
components a computer
uses to process data
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The Components of the System Unit
 The Motherboard
 Contains many of the electronic components
 Chip
 A small piece of semiconducting material usually no
bigger than one-half-inch square and is made up of
many layers of circuits and microscopic components
that carry electronic signals
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The Components of the System Unit
 CPU
 Interprets and carries out the basic instructions that
operate a computer
 Microprocessor manages most of a computer’s
operations
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The Components of the System Unit
 The Control Unit
 A component of the CPU that directs and coordinates most
of the operations in the computer
 Fetch - get the next instruction from memory
 Decode - translate the instruction
 Execute - carry out the command
 Store the result - write the result to memory
 Machine cycle
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The Components of the System Unit
 The Arithmetic/Logic Unit
 Performs the execution part of the machine cycle
 Arithmetic (addition, subtraction, multiplication,
division)
 Comparison (greater than, equal to, less than)
 Logical (AND, OR, NOT)
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The Components of the System Unit
 The System Clock
 Synchronizes all computer operations
 Each tick is called a clock cycle
 Faster clock means more instructions the CPU can
execute each second
 Speed measured in gigahertz (GHz)
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The Components of the System Unit
 Memory
 Used to store data and instructions
 The operating system and other system software
 Application software
 Data being processed by application programs
 Bytes are stored at specific locations or addresses
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The Components of the System Unit
 Memory
 Size of memory is measured by the number of
bytes available
 Volatile memory – contents are lost when the
computer is turned off
 Nonvolatile memory – contents are not lost when
the computer is turned off
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The Components of the System Unit
 Random Access Memory (RAM)
 The memory chips in the system unit
 When the computer starts, certain operating
system files are loaded from a storage device into
RAM
 Synchronous Dynamic RAM (SDRAM)
 Dual Inline Memory Module (DIMM)
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The Components of the System Unit
 Random Access Memory
(RAM)
 RAM Chips
 Smaller in size than
processor chips
 Commonly hold up to 4
gigabytes of memory
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The Components of the System Unit
 Random Access Memory (RAM)
 Configuring RAM
 The more RAM, the more programs and files a
computer can work on at once
 Software usually tells you how much RAM is
required
 For an application to perform optimally, you usually
need more than the minimum specifications
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The Components of the System Unit
 Read-Only Memory
(ROM)
 Cannot be modified
 Contents not lost when
the computer is turned
off
 Flash Memory
 Type of nonvolatile
memory that can be
erased electronically
and rewritten on
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The Components of the System Unit
 Expansion Slots and Expansion Cards
 Expansion slot
 A socket on the motherboard that can hold an expansion
card
 Add new devices or capabilities to the computer
 Expansion card
 Circuit board that enhances functions of a system
component and/or provides connections to peripherals
 Plug and Play
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The Components of the System Unit
 Removable Memory
Devices
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Flash memory cards
USB flash drives
PC Cards
ExpressCard modules
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The Components of the System Unit
 Ports and Connectors
 Port
 Point of attachment to the system unit
 Usually on the back and front of the system unit
 Connectors
 Used to plug into ports
 Male connectors
 Female connectors
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The Components of the System Unit
 Ports and Connectors
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USB
USB 2.0
USB 3.0
FireWire
Bluetooth
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What is Input?
 Any data or instructions you enter into the
memory of a computer
 Data – unprocessed items
 Programs - series of instructions that tells the
computer how to perform a task
 Commands - an instruction given to a computer
program
 User responses - responses to questions or
messages from the software
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What are Input Devices?
 Any hardware component that allows you to enter
data, programs, commands, and user responses
into a computer
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What are Input Devices?
 The Keyboard
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Typing area
Numeric keypad
Toggle keys
Status lights
Arrow keys - arrow control keys
Function keys
Specialized buttons
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What are Input Devices?
 Pointing Devices
 An input device that allows you to control a pointer
on the screen
 Block arrow
 I-beam
 Pointing hand
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What are Input Devices?
 Pointing Devices
 Mouse
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One or two button mouse
Scroll wheel
Moving the mouse pointer
Clicking
Dragging
Double-clicking
Optical mouse
Wireless mouse
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What are Input Devices?
 Touchpad and Pointing
Stick
 Touchpad – small, flat,
rectangular pointing
device that is sensitive to
pressure and motion
 Pointing Stick – pressuresensitive pointing device
shaped like a pencil
eraser
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What are Input Devices?
 Pointing Devices
 Trackball
 Like a mouse, but the
ball mechanism is on
top
 Requires frequent
cleaning
 Good when you have
limited desk space
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What are Input Devices?
 Pointing Devices
 Joystick
 Uses the movement of a vertical lever
 Often used with games
 Wheel
 Steering-wheel type input device
 Used to simulate driving a car or other vehicle
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What are Input Devices?
 Pointing Devices
 Touch and multi-touch
screens
 Monitor has a touch
sensitive panel
 Used to issue simple
commands or choose
from a list of options
 Some models of
desktop and notebook
computers, all tablet
computers, and many
mobile devices have
touch screens
 Kiosks
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What are Input Devices?
 Optical Scanners
 Captures an entire page of text or images such as
photographs or artwork electronically
 Converts the text or image on the original
document into digital data that can be stored on a
storage medium and processed by the computer
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What are Input Devices?
 Pen Input
 Users write, draw,
and tap on a flat
surface to enter input
 Stylus – small metal
or plastic device that
looks like a tiny ink
pen but uses
pressure instead of
ink
 Digital pen – slightly
larger than a stylus
and provides more
functionality
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What are Input Devices?
 Digital Cameras
 Allows you to take
pictures and store the
photographed images
digitally
 Download, or transfer,
pictures to your computer
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What are Input Devices?
 Audio and Video Input
 Audio input
 Entering speech, music, or sound effects
 Sound card
 Speech Recognition
 Computer’s capability of distinguishing spoken words
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What are Input Devices?
 Audio and Video Input
 Video input
 Capturing a full-motion recording onto a computer
and storing the video on a computer’s storage
medium
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What are Input Devices?
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What is Output?
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Text
Graphics
Audio
Video
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What are Output Devices?
 Any computer component capable of conveying
information to the user
 Commonly used output devices
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Display devices
Printers
Data projectors
Facsimile machines
Multifunction devices
Interactive whiteboards
Speakers, headphones, and earphones
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What are Output Devices?
 Display Devices
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Screen housed in a plastic or metal case
Variety of sizes
Cathode ray tube (CRT)
Pixels
Flat-panel displays
 LCD (liquid crystal display) monitors
 LCD screens
 Plasma monitors
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What are Output Devices?
 Plasma Monitors
 Some can measure more than
150 inches wide
 Uses gas plasma technology,
which sandwiches a layer of
gas between two glass plates
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What are Output Devices?
 Monitor Quality
 Resolution (sharpness and clarity)
 Expressed as number of columns and rows
 1600 x 1200
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What are Output Devices?
 Televisions
 iPad users can stream
their music, photos, and
videos wirelessly to a
display device using
AppleTV and AirPlay
 With game consoles, such
as Microsoft’s Xbox 360,
Nintendo’s Wii, and Sony’s
PlayStation 3, the output
device often is a television
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What are Output Devices?
 Printers
 An output device that produces text and graphics
on a physical medium such as paper or
transparency film
 Hard copy (printout)
 Portrait orientation vs. landscape orientation
 Printing requirements vary
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What are Output Devices?
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What are Output Devices?
 Nonimpact Printers
 Do not strike paper
 Much quieter
 Ink-jet printers
 Spray tiny drops of ink
onto the paper
 Both black-and-white
and color
 Photo printers
 Produce photo lab
quality pictures
 Many use ink-jet
technology
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What are Output Devices?
 Nonimpact Printers
 Laser printers
 High-speed, high-quality
nonimpact printer
 Very high quality
resolution
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What are Output Devices?
 Data Projectors
 Allows an audience to
view output
 LCD projectors
 Digital light processing
(DLP) projector
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What are Output Devices?
 Facsimile (Fax) Machine
 Used to transmit and
receive an image of a
document over a
telephone line
 Stand-alone
 Fax modem
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What are Output Devices?
 Multifunction Devices
 Can print, scan, copy
and fax
 Less space
 Lower cost than separate
units
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What are Output Devices?
 Interactive whiteboards
 Touch-sensitive device,
resembling a dry-erase
board
 A presenter controls the
computer program used to
display the image by:
 Clicking a remote control
 Touching the whiteboard
 Drawing on or erasing the
whiteboard
 Writing on a special tablet
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What are Output Devices?
 Speakers, Headphones,
and Earphones
 Voice output
 Audio output device
 Internal speaker
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What is Storage?
 The media on which data,
instructions, and information
are kept
 The devices that record and
retrieve data, instructions,
and information
 Similar to a filing cabinet
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Storage Media and Devices
 Storage medium
 Also called secondary storage
 Physical material
 Storage device
 Mechanism used to record and retrieve these items
to and from a storage medium
 Capacity measured in megabytes or gigabytes
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Storage Media and Devices
 Magnetic Disk
 Uses magnetic patterns to
store data, instructions,
and information on the
disk’s surface
 Formatting is the process
of preparing a disk for
reading and writing by
organizing the disk into
storage locations called
tracks and sectors
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Storage Media and Devices
 Hard Disks
 Provide large storage capacity
 Sizes range from 320 GB to 1.5 TB
 Consists of several inflexible, circular disks, called
platters
 Magnetic storage device
 Formatting
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Storage Media and Devices
 Miniature and Portable Hard Disks
 Miniature hard disks are found in consumer
electronics and have greater storage capacities
than flash memory
 External hard disks connect to a
USB or FireWire port by a cable
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Storage Media and Devices
 Solid State Drives
 A storage device that typically uses flash memory
to store data, instructions, and information and
contains no moving parts
 Range in size from 16 GB to 512 GB
 Used in all types of computers
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Storage Media and Devices
 Optical discs
 Type of storage medium that consists of a flat,
round, portable disc made of metal, plastic, and
lacquer that is written to and read from using a
laser
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Storage Media and Devices
 CDs and DVDs
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Optical storage media
Used to distribute software
Laser reads pits on the surface
Used on multimedia computers
Several types
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Storage Media and Devices
 Care of Optical Discs
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Can last up to 100 years if properly cared for
Never bend a disc
Avoid extreme temperatures and humidity
Keep away from contaminants
Do not stack or touch discs
Use a protective case (jewel box or disc storage
case)
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Storage Media and Devices
 CD-ROM
 Compact disc read-only
memory
 Can contain text,
graphics, video, as well
as sound
 Can hold up to 1 GB
 Used to distribute
software
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Storage Media and Devices
 CD-R and CD-RW
 Compact disc-recordable
 Can write on each part of the disc only one time
 Cannot be erased
 Compact disc-rewriteable
 Can write on multiple times
 Erasable disc
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Storage Media and Devices
 DVD and BD
 Digital video disc read-only memory (DVD-ROM)
 Can store from 4.7 GB to 17 GB
 High quality
 DVD-ROM drives
 BD (Blu-ray Disc) has storage capacities of 100GB,
with expectations of exceeding 200 GB
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Storage Media and Devices
 Miniature Mobile Storage Media
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Storage Media and Devices
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Storage Media and Devices
 USB Flash Drive
 Storage device that plugs into a USB port on a
computer or mobile device
 Smart Card
 Similar in size to a credit card
 Stores data on a thin microprocessor embedded in
the card
 Cloud Storage
 Rapidly growing Internet service that provides
storage to computer users
 Apple’s iCloud
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Storage Media and Devices
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