1. Hardware for Educators
Chapter 4
Hardware for Educators

2. The System Unit System unit
Boxlike case that houses the electronic components of the computer that are used to process data

3. Data Representation Analog vs. Digital Digital Two states (1) on
(0) off

4. Data Representation Binary number system
Combination of ones and zeroes represent characters

5. Data Representation ASCII
American Standard Code for Information Interchange
Converting a keyboard stroke into a byte

7. 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

9. 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

10. 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

11. 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)

12. 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)

13. 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

14. Seats in a stadium are similar to addresses in memory:
A seat in memory holds one person at a time, and an address in memory holds a single byte
Both a seat and an address can be empty
A seat has a unique identifying number and so does an address

15. 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

16. 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)

17. 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)

18. 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

19. 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

20. 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

21. The Components of the System Unit
Expansion Slots and Expansion Cards
Three common types
Video card
Sound card
Internal modem
Plug and Play

22. 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

23. 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

24. What are Input Devices?
Any hardware component that allows you to enter data, programs, commands, and user responses into a computer

25. What are Input Devices? The Keyboard Typing area Numeric keypad
Toggle keys
Status lights
Arrow keys - arrow control keys
Function keys
Specialized buttons

27. 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

28. What are Input Devices? Mouse Pointing Devices One or two button mouse
Moving the mouse pointer
Clicking
Dragging
Double-clicking
Optical mouse
Cordless mouse

29. What are Input Devices? Touchpad and Pointing Stick
Touchpad – small, flat, rectangular pointing device that is sensitive to pressure and motion
Pointing Stick – pressure-sensitive pointing device shaped like a pencil eraser

30. What are Input Devices? Pointing Devices Trackball
Like a mouse, but the ball is on top
Often used on portable computers

31. What are Input Devices? Pointing Devices Joystick Wheel
Uses the movement of a vertical lever
Often used with games
Wheel
Steering-wheel type input device
Used to simulate driving a car

32. 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

33. 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

34. 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

35. What are Input Devices? Digital Cameras
Allows you to take pictures and store the photographed images digitally
Download, or transfer, pictures to your computer

36. 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

37. 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

38. What are Input Devices?
Input Devices for PDAs, Smart Phones, and Tablet PCs
Stylus
Voice Input
Portable keyboard
Scanner
On-screen keyboard
Digital camera

39. What is Output?
Text
Graphics
Audio
Video

40. 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

41. 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

43. 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

44. What are Output Devices?
Large Display Monitors
High-definition television (HDTV)
Gas plasma monitor

45. 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

47. 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

48. 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

49. 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

50. What are Output Devices?
Nonimpact Printers
Laser printers
High-speed, high-quality nonimpact printer
Very high quality resolution

51. What are Output Devices?
Data Projectors
Allows an audience to view output
LCD projectors
Digital light processing (DLP) projector

52. 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

53. What are Output Devices?
Multifunction Devices
Can print, scan, copy and fax
Less space
Lower cost than separate units

54. What are Output Devices?
Audio Output
Produce music, speech, or other sounds
Speakers
Headsets

55. 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

56. 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

57. 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

58. 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

59. 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

60. 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

61. 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

63. 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

64. 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

65. 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

66. 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

67. Storage Media and Devices
Miniature Mobile Storage Media

68. Storage Media and Devices

69. 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

70. 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

71. 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

72. Hardware for Educators
Chapter 4 Complete
Hardware for Educators

73. HOW TO PURCHASE A PERSONAL COMPUTER
Buyer’s Guide
HOW TO PURCHASE A PERSONAL COMPUTER

74. 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?

75. 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

76. 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

77. 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

78. 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

79. 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

80. 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

81. 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

82. 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

83. 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 is essential with a Tablet PC
Review available accessories to purchase with your Tablet PC

84. 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 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

85. 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

86. 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