1. Chapter 2: Computer Hardware
Chapter 4: File Management, Virus Protection, and Backup
Chapter 1: Computer, Internet, Web, and Basics
Chapter 2: Computer Hardware 1 1 1 1

2. Chapter 2: Computer Hardware
Chapter 2 Preview
After this chapter, you should be able to:
Explain why most computers are digital
Describe the role of the ALU
List factors that affect performance
Explain RAM
Compare storage technologies
Chapter 2: Computer Hardware

3. Chapter 2: Computer Hardware
Chapter 2 Preview
After this chapter, you should be able to:
Explain the factors that might help a shopper decide whether to purchase a CRT, LCD, or plasma monitor
Compare and contrast the technologies and applications for printers
Describe computer’s expansion bus
Explain hardware compatibility considerations
Chapter 2: Computer Hardware

4. Chapter 2: Computer Hardware
Chapter 2 Outline
Section A
Data Representation and Digital Electronics
Section B
Microprocessors and Memory
Section C
Storage Devices
Section D
Input and Output Devices
Chapter 2: Computer Hardware

5. Chapter 2 Computer Hardware
Section A: Data Representation and Digital Electronics
Computer Concepts 8th Edition Parsons/Oja

6. Data Representation: How do computers represent data digitally?
Data representation makes it possible to convert letters, sounds, and images into a form computers can use for processing
A digital device works with discrete data, such as the digits 1 and 0
An analog device works with continuous data
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7. Data Representation: How do computers represent data digitally?
Computers are digital
Just as a standard light switch is a simpler technology than a dimmer, so is digital when compared to analog
digital
analog
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8. How does a computer represent numbers?
The binary number system (base 2) uses only two digits 0, and 1
The following table lists some decimal numbers and their binary equivalent:
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9. How can a computer represent words and letters using bits?
Character data is composed of letters, symbols, and numerals that are not used in arithmetic operations
ASCII requires only 7 bits for each character
Extended ASCII uses 8 bits to represent each character
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10. How can a computer represent words and letters using bits?
EBCDIC is an alternative 8-bit used by older IBM systems
Unicode uses 16 bits and provides codes for 65,000 characters
Used for foreign language support
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11. How does a computer convert sounds and pictures into codes?
Sounds and pictures must be transformed into a format the computer can understand
A computer must digitize colors, notes, and instrument sounds into 1s and 0s
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12. Chapter 2: Computer Hardware
Quantifying Bits and Bytes: How can I tell the difference between bits and bytes?
A bit is one binary digit (b)
A byte is 8 bits (B)
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13. Chapter 2: Computer Hardware
Quantifying Bits and Bytes: How can I tell the difference between bits and bytes?
Kilo- means a 1000, Mega- means million, Giga -means billion
Kilobit (Kb) is 1,024 bits
Kilobyte (KB) is 1, 024 bytes
Megabyte (MB) is 1,048,576 bytes
Gigabyte (GB) is 1,073,741,824 bytes
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14. How does a computer store and transport all these bits?
Bits take the form of electrical pulses that can travel over circuits
This is almost the same way as electricity flows over a wire when you turn on a light switch
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15. What’s inside the system unit?
Desktop units are designed with expectation that the home user may add or update the equipment
Small desktop and notebook computers are not designed for users to access all areas
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16. What’s inside the system unit?
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17. Chapter 2: Computer Hardware
What’s a computer chip?
Most electronic components inside a computer are integrated circuits
Thin slices of silicon crystal packed with microscopic circuit elements
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18. Chapter 2: Computer Hardware
What’s a computer chip?
Semiconducting materials are used to fabricate a chip
Types of chips:
DIPs
DIMMs
PGAs
SEC cartridge
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19. Chapter 2: Computer Hardware
What’s a computer chip?
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20. How do chips fit together to make a computer?
The system board houses all essential chips and provides connecting circuitry between them
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21. How do chips fit together to make a computer?
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22. Chapter 2 Computer Hardware
Section B: Microprocessors and Memory
Computer Concepts 8th Edition Parsons/Oja

23. Microprocessor Basics: What exactly is a microprocessor?
An integrated circuit designed to process instructions
CPU on a chip
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24. How does a microprocessor work?
The CPU has two parts
ALU (arithmetic logic unit)
Performs arithmetic operations
Performs logical operations
Uses registers to hold data being processed
The CPU’s control unit directs and coordinates processing
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25. Can I replace my computer’s microprocessor with a faster one?
Technically yes, but most computer owners rarely do
Reasons not to upgrade
Cost
Technical factors – speed
Do research before you upgrade your microprocessor
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26. Random Access Memory: What is RAM?
A temporary holding area for data, application program instructions, and the operating system
As you type, characters are held in RAM
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27. How much RAM does my computer need?
RAM is primary storage (main memory)
Measured in megabytes (MB) or gigabytes (GB)
Today’s computers have between 128 MB and 2 GB of RAM
Depends on software you use
You can purchase additional RAM
A computer can use disk storage to simulate RAM. This is called virtual memory
Not as fast as RAM
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28. Do all computers use the same type of RAM?
No. RAM components vary in speed, technology, and configuration
Speed is measured in nanoseconds. 1 nanosecond (ns) is 1 billionth of a second
It can also be expressed in MHz (millions of cycles per second)
SDRAM (Synchronous Dynamic RAM)
RDRAM (Rambus Dynamic RAM)
Figure 2-20
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29. Read-Only Memory: How is ROM different from RAM?
Type of memory circuitry that holds the computer’s startup routine
Permanent and non-volatile
Only way to change the instructions on a ROM chip is to replace the chip
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30. CMOS Memory: Where does a computer store its basic hardware settings?
A computer needs a semi-permanent way of keeping boot data
CMOS memory holds data but requires very little power to retain its contents
Retains important computer settings after you turn the power off
Can run by a battery on the system board
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31. Where does a computer store its basic hardware settings?
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32. How do I get the best computer for my money?
Different buyers have different needs
Assess your budget and think about how you plan to use your computer
Look at ads and visit online computer stores
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33. Chapter 2 Computer Hardware
Section C: Storage Devices
Computer Concepts 8th Edition Parsons/Oja

34. Chapter 2: Computer Hardware
Storage Basics: What are the basic components of a data storage system?
A storage medium is the disk, tape, CD, DVD, paper or other substance that contains data
A storage device is the mechanical apparatus that records and retrieves data from a storage medium
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35. How does magnetic storage work?
Stores data by magnetizing microscopic particles on the disk or tape surface
Read-write head - mechanism in the disk drive that reads and writes magnetized particles that represent data
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36. How does magnetic storage work?
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37. How does optical storage work?
Stores data as microscopic light spots (lands) and dark spots (pits) on the disk surface
Less susceptible to environmental damage than data recorded on magnetic media
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38. How does optical storage work?
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39. How does solid state storage work?
Stores data in a non-volatile, erasable, low-power chip
Some solid state storage requires a device called a card reader to transfer data to or from a computer
Provides faster access to data than magnetic or optical storage technology because it includes no moving parts
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40. Can I add storage devices to my computer?
Devices can be added into empty drive bays
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41. What is floppy disk technology?
A floppy disk is a round piece of flexible mylar plastic covered with a thin layer of magnetic oxide and sealed inside a protective casing
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42. How much data can a HD DS disk and a Zip disk hold?
HD DS 3½” diskettes have capacity of 1.44 MB
Zip disks come in 100 MB, 250 MB, and 750 MB versions
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43. What are the advantages and disadvantages of HD DS floppy disks?
Major advantage – portability
Major disadvantage – not a particularly speedy device and limited storage capacity
Slowly being replaced by solid state technology
Today most software vendors use CD-ROM or DVD-ROM disks instead
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44. How can ZIP disks store more data than standard floppy disk?
Disk density - closeness and size of magnetic particles on the disk’s surface
Zip disks store data at a higher density than a standard 3½” floppy disk
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45. How does a hard disk work?
Hard disk platter - a flat, rigid disk made of aluminum or glass and coated with magnetic iron oxide particles
Density far exceeds floppy disk
Hard disk - one or more platters and their associated read-write heads
Preferred type of main storage
Miniature hard drives store 20 to 40 GB
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46. How does a hard disk work?
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47. What’s the downside of hard disk storage?
Head crash - when a read-write head runs into a dust particle or other contaminant on the disk
Head crash damages some data on disk
Triggered by jarring the hard disk while in use
Not limited to hard disks
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48. Tape Storage: What’s the purpose of a tape drive?
Tape backup - copy of data on hard disk stored on magnetic tape
Relatively inexpensive
Primarily used on business computers
Not suitable for everyday storage tasks
Sequential-access storage medium
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49. Chapter 2: Computer Hardware
CD and DVD technology: Is there a difference between CD and DVD technology? CD
Holds up to 80 minutes of music or 700 MB of data
DVD
Holds about 4.7 GB of data
A double layer DVD has two recordable layers on the same side and can store 8.5 GB of data
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50. How do CD and DVD drives work?
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51. How do CD and DVD drives work?
Recordable technology uses a laser to change the color in a dye layer sandwiched beneath the clear plastic disk surface
Rewritable technology uses “phase change” technology to alter a crystal structure on the disk surface
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52. Can I use a single drive to work with any CD or DVD media?
Figure 2-33
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53. Chapter 2: Computer Hardware
Are rewritable CD or DVD drives an acceptable replacement for a hard disk?
It is slower than hard disk access
Not yet a suitable replacement
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54. Is my computer DVD drive the same as the one connected to my TV?
Not exactly
Movie files are still very large
Television DVD drives include MPEG decoding circuitry
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55. Solid State Storage: When would I use solid state storage?
Portable, provides fast access to data and uses very little power
USB flash drive
CompactFlash card
MMC
SecureDigital
SmartMedia
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56. Chapter 2 Computer Hardware
Section D: Input and Output Devices
Computer Concepts 8th Edition Parsons/Oja

57. Chapter 2: Computer Hardware
Basic Input Devices: What devices can I use to get data into a computer?
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58. What are my options for display devices?
CRT (cathode ray tube)
LCD (liquid crystal display)
LCDs are clearer, have low radiation emission, are portable, and compact
LCDs are also more expensive than CRTs
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59. What are my options for display devices?
Plasma screen technology
Lightweight, compact, and more expensive than CRT monitors
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60. How does an ink jet printer work?
Nozzle-like print head that sprays ink onto paper to form characters and graphics
Most ink jet printers use CMYK color
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61. How do laser printers compare to ink jet printers?
A laser printer paints dots of light on a light-sensitive drum
Higher quality than ink jet
More expensive to buy than ink jet
Less expensive to operate than ink jet
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62. How do laser printers compare to ink jet printers?
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63. What is a dot matrix printer?
Produce characters and graphics by using a grid of fine wires
Introduced in 1970s
Low quality output
Used for “back-office” applications that demand low operating cost and dependability
Can print multipart carbon forms
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64. What is a dot matrix printer?
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65. What other printer technologies are available?
Thermal transfer printer
Uses page-sized ribbons coated with wax
Print head consists of heating elements to melt the wax
Dye sublimation printer
Similar to wax, but page-sized ribbon contains dye
Print heads diffuse the dye
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66. Printers: What features should I look for in a printer?
Resolution
Measured in dpi (dots per inch)
Print speed
Measured either by pages per minute (ppm) or characters per second (cps)
Color takes longer than black and white
Text prints faster than graphics
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67. What features should I look for in a printer?
Duty cycle - indication of the number of pages a printer can be expected to print per month
Indicates maintenance costs
Operating costs
Printers require ongoing costs including ribbons, ink cartridges, and toner
Per copy cost is the cost of printing a page with an average amount of text, graphics, and color
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68. What features should I look for in a printer?
Duplex capability
A printer with duplex capability can print on both sides of the paper
Memory
A computer sends data for a printout to the printer along with a set of instructions on how to print the data
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69. Chapter 2: Computer Hardware
Installing Peripheral Devices: Is it difficult to install a new peripheral device?
Internal devices
Tools required
Screwdriver
Directions
Before installing
Unplug the computer
Ground yourself
Installing
Follow the directions
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70. What’s an expansion slot?
Expansion slot - long, narrow socket on the system board into which you can plug an expansion card
Expansion card - small circuit board that provides computer with ability to control storage, input or output device
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71. What’s an expansion slot?
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72. What’s an expansion slot?
ISA (Industry Standard Architecture)
Used today only for some modems and other relatively slow devices
PCI (Peripheral Component Interconnect)
Offers fast transfer speeds and a 32-bit or 64-bit data bus
AGP (Accelerated Graphics Port)
Provides a high-speed data pathway primarily used for graphics cards
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73. Do notebook computers contain expansion slots?
Equipped with a special type of external slot called a PCMCIA slot
Typically a notebook only has one slot, but the slot can hold more than one PC card (PCMCIA expansion cards)
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74. What is an expansion port?
Used to connect a peripheral device
Expansion port - any connector that passes data in and out of a computer or peripheral device
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75. What is an expansion port?
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76. How do I know which cable to use?
Serial DB-9
Parallel DB-25M
USB
SCSI C-50F
IEEE 13394
VGA HDB-15
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77. Chapter 2: Computer Hardware
Conclusion
You should now be able to:
Explain why most computers are digital
Describe the role of the ALU
List factors that affect performance
Explain RAM
Compare storage technologies
Describe computer’s expansion bus
Explain hardware compatibility considerations
Chapter 2: Computer Hardware