Shelly Cashman Series Discovering Computers A Link to the
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Transcript Shelly Cashman Series Discovering Computers A Link to the
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
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
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
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
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?
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
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
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
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
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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