Teachers Discovering Computers
Integrating Technology and
Digital Media in the Classroom
4th 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
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Chapter Objectives
 List the characteristics of a keyboard and identify
various types of keyboards
 Identify various types of pointing devices
 Differentiate among the four types of output
 Identify the different types of output devices
 Explain differences among various types of
printers
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Chapter Objectives
 Differentiate between storage and memory
 Identify types of storage media and devices
 Explain how data is stored on 3.5-inch disks, hard
disks, CD-ROMs, and DVDs
 Differentiate between CD-ROMs and DVD-ROMs
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The System Unit
 System unit
 Boxlike case that houses
the electronic
components of the
computer that are used
to process data
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Data Representation
 Analog vs. Digital
 Digital
 Two states
 (1) on
 (0) off
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Data Representation
 Binary number system
 Combination of ones and zeroes represent
characters
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Data Representation
 ASCII
 American Standard Code for Information
Interchange
 Converting a keyboard stroke into a byte
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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 on which
one or more integrated circuits are etched
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The Components of the System Unit
 CPU and Microprocessor
 Interprets and carries out the basic instructions
that operate a computer
 Microprocessor contains the CPU in a PC
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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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Chapter 4: Hardware for Educators
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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 megahertz (MHz) and
gigahertz (GHz)
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The Components of the System Unit
 Memory
 Used to store data, instructions, and information
 The operating system and other system software
 Application programs
 Data being processed by application programs
 Bytes are stored at specific locations or addresses
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Seats in a stadium are similar to addresses in memory:
(1)
A seat in memory holds one person at a time, and an address in memory holds a
single byte
(2)
(3)
Both a seat and an address can be empty
A seat has a unique identifying number and so does an address
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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 powered down
 Nonvolatile memory – contents are not lost when
the computer is powered down
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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, operating system files
are loaded from a hard disk 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
 Packaged on circuit
boards called single
inline memory modules
(SIMMs) or dual inline
memory modules
(DIMMs)
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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
 Necessary RAM depends on what type of work the
computer is used for
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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
 An opening, or socket, where a circuit board can be
inserted into the motherboard
 Add new devices or capabilities to the computer
 Expansion card
 Circuit boards, such as a modem or graphics card, that
add new capabilities to the computer
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The Components of the System Unit
 Expansion Slots and Expansion Cards
 Three common types
 Video card
 Sound card
 Internal modem
 Plug and Play
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The Components of the System Unit
 PC Card
 Thin credit card-sized device that adds capabilities
to small computers
 Flash Memory Card
 Removable memory device that allows users to
transfer data and information from a mobile device
to a desktop computer
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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
 New ports
 USB
 USB 2.0
 FireWire
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What is Input?
 Any data or instructions you enter into the
memory of a computer
 Data - unorganized facts
 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
Moving the mouse pointer
Clicking
Dragging
Double-clicking
Optical mouse
Cordless 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 is on top
 Often used on portable
computers
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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
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What are Input Devices?
 Pointing Devices
 Touch screen
 Monitor has a touch
sensitive panel
 Used to issue simple
commands or choose
from a list of options
 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
disk 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
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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 music, speech, 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
 Entering a full-motion recording into a computer and
storing the video on a hard disk or some other
medium
 Video capture card
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What are Input Devices?
 Input Devices for PDAs,
Smart Phones, and Tablet
PCs






Stylus
Voice Input
Portable keyboard
Scanner
On-screen keyboard
Digital camera
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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







Monitors
Printers
Data Projectors
Facsimile machines
Multifunction devices
Speakers
Headsets
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What are Output Devices?
 Monitors and Display Devices





Screen housed in a plastic or metal case
Variety of sizes
Cathode ray tube (CRT)
Pixels
LCD (liquid crystal display) monitors
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What are Output Devices?
 Large Display Monitors
 Allow an audience or a
group of students in a
classroom to easily view
images and multimedia
displayed on a computer
 Available from 27 to 36
inches
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What are Output Devices?
 Large Display Monitors
 High-definition television
(HDTV)
 Gas plasma monitor
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What are Output Devices?
 Flat Panel Monitors and
Displays
 Uses liquid crystal instead
of a CRT
 Consume less than 1/3 the
power of a CRT
 Thinner and lighter than a
CRT
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What are Output Devices?
 Monitor Quality
 Resolution (sharpness and clarity)
 Expressed as number of columns and rows
 800 x 600
 1800 x 1440
 Dot pitch
 Refresh rate
 ENERGY STAR
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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 vs. landscape
 Printing requirements vary
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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
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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 phone
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?
 Audio Output
 Produce music, speech,
or other sounds
 Speakers
 Headsets
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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
 Like 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
 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
 Floppy Disks
 Portable, inexpensive
storage medium
consisting of a thin
circular flexible film
enclosed in a square
shaped plastic shell
 Several sizes
 8-inch
 5.25-inch
 3.5-inch
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Storage Media and Devices
 Zip Disks
 Capacities greater than
100 MB
 Many uses
 Graphics, audio, or
video
 Transporting files
 Backups
 Being replaced with USB
flash drives and other
portable storage devices
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Storage Media and Devices
 Hard Disks
 Provide large storage capacity and high speed
data access
 Sizes range from 40 GB to 300 GB
 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
 CDs and DVDs





Optical storage media
Used to distribute software
Laser reads pits on the surface
Used on multimedia computers
Several types
 CD-ROM
 DVD-ROM
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Storage Media and Devices
 Care of CDs and DVDs






Can last from 5 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
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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 650 MB of data
 Used for today’s complex
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-ROM and DVD+RW
 Digital video disc read-only memory (DVD-ROM)
 Can store from 4.7 GB to 17 GB
 High quality
 DVD-ROM drives
 May replace CDs, VCRs, and VHS tapes
 Digital video disc+rewritable (DVD+RW)
 Can write on multiple times
 Erasable disc
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Storage Media and Devices
 Miniature Mobile Storage Media
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Storage Media and Devices
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Chapter Summary
 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
Chapter 4: Hardware for Educators
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Chapter Summary
 List the characteristics of a keyboard and identify
various types of keyboards
 Identify various types of pointing devices
 Differentiate among the four types of output
 Identify the different types of output devices
 Explain differences among various types of
printers
Chapter 4: Hardware for Educators
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Chapter Summary
 Differentiate between storage and memory
 Identify types of storage media and devices
 Explain how data is stored on 3.5-inch disks, hard
disks, CD-ROMs, and DVDs
 Differentiate between CD-ROMs and DVD-ROMs
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Teachers Discovering Computers
Integrating Technology and
Digital Media in the Classroom
4th Edition
Chapter 4 Complete
Hardware for Educators
Buyer’s Guide
HOW TO PURCHASE
A PERSONAL COMPUTER
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How to Purchase
a Personal Computer
 Do you want a desktop computer, mobile
computer, or personal mobile device?
 For what purposes will you use the computer?
 Should the computer be compatible with the
computers at school or work?
 Should the computer be a Mac or PC?
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How to Purchase
a Desktop Computer
 Determine the specific software you want to use
on your computer
 Look for bundled software
 Avoid buying the least powerful computer
available
 Consider upgrades to the mouse, keyboard,
monitor, printer, microphone, and speakers
 Determine whether you want to use telephone
lines or broadband (cable or DSL) to access the
Internet
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How to Purchase
a Desktop Computer
 If you are using a dial-up or wireless connection to
connect to the Internet, select an ISP or OSP
 Use a worksheet to compare computers, services, and
other considerations
 If you are buying a new computer, you have several
purchasing options: buying from your school bookstore, a
local computer dealer, a local large retail store, or
ordering by mail via telephone or the Web
 If you are buying a used computer, stay with name brands
such as Dell, Gateway, Hewlett-Packard, and Apple
 If you have a computer and are upgrading to a new one,
then consider selling or trading in the old one
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How to Purchase
a Desktop Computer





Be aware of hidden costs
Consider more than just price
Avoid restocking fees
Use a credit card to purchase your new computer
Consider purchasing an extended warranty or
service plan
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How to Purchase
a Notebook Computer
 Purchase a notebook computer with a sufficiently
large active-matrix screen
 Experiment with different keyboards and pointing
devices
 Make sure the notebook computer you purchase
has a CD and/or DVD drive
 If necessary, upgrade the processor, memory,
and disk storage at the time of purchase
 The availability of built-in ports on a notebook
computer is important
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How to Purchase
a Notebook Computer
 If you plan to use your notebook computer for
note-taking at school or in meetings, consider a
notebook computer that converts to a Tablet PC
 Consider purchasing a notebook computer with a
built-in wireless card to connect to your home
network
 If you are going to use your notebook computer
for long periods without access to an electrical
outlet, purchase a second battery
 Purchase a well-padded and well-designed
carrying case
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How to Purchase
a Notebook Computer
 If you travel overseas, obtain a set of electrical
and telephone adapters
 If you plan to connect your notebook computer to
a video projector, make sure the notebook
computer is compatible with the video projector
 For improved security, consider a fingerprint
scanner
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How to Purchase a Tablet PC
 Make sure the Tablet PC fits your mobile
computing needs
 Decide whether you want a convertible or pure
Tablet PC
 Be sure the weight and dimensions are
conducive to portability
 Port availability, battery life, and durability are
even more important with a Tablet PC than they
are with a notebook computer
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How to Purchase a Tablet PC
 Experiment with different models of the Tablet PC
to find the digital pen that works best for you
 Check out the comfort level of handwriting in
different positions
 Make sure the LCD display device has a
resolution high enough to take advantage of
Microsoft’s ClearType technologies
 Test the built-in Tablet PC microphone and
speakers
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How to Purchase a Tablet PC
 Consider a Tablet PC with a built-in PC video
camera
 Review the docking capabilities of the Tablet PC
 Wireless access to the Internet and your e-mail is
essential with a Tablet PC
 Review available accessories to purchase with
your Tablet PC
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How to Purchase
a Personal Mobile Device
 Determine the programs you plan to run on your
device
 Consider how much you want to pay
 Determine whether you need wireless access to
the Internet and e-mail or mobile telephone
capabilities with your device
 For wireless devices, determine how and where
you will use the service
 Make sure your device has enough memory
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How to Purchase
a Personal Mobile Device
 Practice with the touch screen, handwriting
recognition, and built-in keyboard before deciding
on a model
 Decide whether you want a color display
 Compare battery life
 Seriously consider the importance of ergonomics
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How to Purchase
a Personal Mobile Device
 Check out the accessories
 Decide whether you want additional functionality
 Determine whether synchronization of data with
other Devices or personal computers is important
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