Transcript Document 7330220

Technology In Action
© 2008 Prentice-Hall, Inc.
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Technology In Action
Chapter 6
Evaluating Your System:
Understanding and Assessing Hardware
© 2008 Prentice-Hall, Inc.
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Chapter Topics
• To buy or upgrade?
• Evaluating your system:
– CPU
– RAM
– Storage devices
– Video output
– Sound systems
– Computer ports
• System reliability
© 2008 Prentice-Hall, Inc.
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To Buy or To Upgrade?
• Things to consider:
– Moore’s Law
The number of transistors inside
a CPU will double every
18 months
© 2008 Prentice-Hall, Inc.
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To Buy or To Upgrade?
• Things to consider:
– The capacity of memory chips increases about
60 % every year
– Hard disk drives have been growing in storage
capacity by about 50% every year
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Assessing Your Hardware:
Evaluating Your System
• Assess the computer’s subsystems
• The subsystems include
– CPU
– RAM
– Virtual memory
– Storage devices
– Video
– Audio
– Ports
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Evaluating the CPU
• How does the CPU work?
– Control unit
– Arithmetic logic unit (ALU)
– Machine cycle:
• Instruction Cycle
– Fetch
– Decode
• Execution Cycle
– Execute
– Store
– Speed:
• MHz
• GHz
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How Does the CPU Work
• The CPU
– Processes instructions
– Performs calculations
– Manages the flow of information through a
computer system
– Is responsible for processing the data you
input into information
• Located on the Motherboard
– The primary circuit board of the computer
system
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How Does the CPU Work
• The CPU is composed of two units
– The Control Unit
• Instruction Control Unit
• ICU
• Coordinates the activities of all other computer
components
– The Arithmetic Logic Unit
• ALU
• Responsible for performing all arithmetic operations
and comparison decisions
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How Does the CPU Work
• Every time the CPU performs a program
instruction, it goes through the same series
of steps (Machine Cycle)
– It fetches the required piece of data or
instruction from RAM
– It decodes the instruction into something the
computer can understand
– It executes the instruction
– It stores the result to RAM
• The computer goes through these machine
cycles at a steady and constant pace
– Clock Speed
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How Does the CPU Work
• The System Clock
– Controls clock speed
– Works like a metronome in music
– Keeps a steady beat, regulating the speed at
which the processor goes through machine
cycles
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How Does the CPU Work
• Processors process millions/billions of
machine cycles each second
• Processor speed is measured in units of
Hertz (Hz)
– Machine cycles per second
• MHz – 1 million instructions per second
• GHz – 1 billion instructions per second
• 3.8 GHz – 3.8 billion instructions per second
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How Does the CPU Work
• CPU Usage
– The percentage of time your CPU is working
– Windows XP Task Manager
– Sound Byte
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Evaluating CPU Features
• Some CPUs are optimized to process
multimedia instructions
• Intel CPUs called Core Duo processors
– Use less power than dual processors
– Increase multitasking performance
• Intel has more than 17 other designs for
chips with more than one core
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Upgrading the CPU
• Expensive
• Easy to install
• Motherboard
compatibility
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Upgrading the CPU
• Replacing the CPU is expensive
• Not all CPUs are interchangeable
• The replacement CPU must be compatible with
the Motherboard
• Upgrading your CPU will affect only processing
speed
• Your system’s overall performance depends on
many other factors, including the amount of
RAM installed and the hard disk speed of your
hard drive
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Evaluating RAM
• Random access memory (RAM):
– Temporary storage (memory)
– Volatile
• Memory modules:
– SIMM
– DIMM
– RIMM
• Types of RAM:
– SRAM
– DRAM
– SDRAM
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Evaluating RAM
• Random access memory (RAM):
– Your computer’s temporary storage space
– Short term memory
• It remembers everything that the computer needs
to process the data into information (data and
software instructions)
• As long as the computer is on. When the power is
off, the data stored in RAM is cleared out
– Volatile
– It’s about one million times faster for the
CPU to retrieve a piece of data from
RAM than from a hard disk drive
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Evaluating RAM
• Random access memory (RAM):
– Located on the Motherboard
• Types of RAM
– DRAM
– SRAM – Static RAM
– SDRAM – Synchronous DRAM
– DDR2 SDRAM RAM Double Data Rate
SDRAM
• Currently, DDR2 SDRAM is very common
today
• How much RAM do I have – Page 279
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How Much Ram is Needed?
• To determine how much ram
You need, you must look at the
memory requirements of each
program and add them up
System Software
Windows XP
128 MB
Productivity Software
MS Office Pro
128 MB
Entertainment Software Windows Media Player
64 MB
Graphics
128 MB
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MS Picture It!
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How Much Ram is Needed?
•
•
•
•
RAM for System Software
RAM for Productivity Software
RAM for Entertainment
RAM for Graphics Programs
System Software
Windows XP
128 MB
Productivity Software
MS Office Pro
128 MB
Entertainment Software Windows Media Player
64 MB
Graphics
128 MB
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MS Picture It!
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How Much Ram is Needed?
• Because RAM is the temporary holding
space for all the data and instructions that
the computer uses when it’s on, most
computer users need quite a bit of RAM
• It’s not unusual to have 1 GB of RAM or
more on a newer home system
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How Much Ram is Needed?
• At a minimum
– You need enough RAM to run the OS plus
whatever software applications you’re using
– Plus additional RAM to hold the data you’re
inputting
• The maximum limit with Windows XP is 4 GB
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Adding RAM
• Increase system
performance
• Things to consider:
– Type of RAM module
– Amount of RAM:
•
•
•
•
Maximum limit
Number of slots
Operating system
Applications running at the
same time
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Evaluating Storage
• RAM is a form of temporary storage
– Volatile storage
– Anything residing in RAM is not permanently
saved
• It’s critical to have means to store data
and software applications permanently
• Several storage options exist
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Evaluating Storage
• Types of storage devices:
– Hard drive
– Floppy drive
– Zip disk drive
– CD/DVD
– Flash memory
• Nonvolatile storage
– Permanent storage devices
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The Hard Disk Drive
• Storage capacity up to 500 GB
– The largest storage capacity of any storage device
– Offers the most GB of storage per dollar
• Access time is measured in
milliseconds (Thousandths of
seconds
– The time it takes a storage device to
locate its stored data and make it
available for processing
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The Hard Disk Drive
• Data transfer rate is measured in megabits
(megabytes per second)
– Transfer data to other computer components
• Spindle speed is measured in revolutions per
minute (rpm)
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How a Hard Disk Works
• Composed of several iron
oxide- coated platters
stacked on a spindle
• When data is saved to a
hard disk, a pattern of
magnetized spots is
created on the iron oxide
coating each platter
Platters
Read/write
head
– Each spots = 1
– Spaces not spotted = 0
• 0s and 1s are binary bits
Access arms
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How a Hard Disk Works
• Between each platter are
read/write heads that read
and write magnetized data
• The read/write heads move
from the outer edge of the
spinning platters to the
center to read and write the
magnetized data to/from
the hard disk
Platters
Read/write
head
Access arms
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How a Hard Disk Works
• When data stored on the
hard disk is retrieved, your
computer translates the
patterns of 0s and 1s into
the data you saved
Platters
Read/write
head
Access arms
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The Hard Disk Drive
• Hard drive capacity is measured in MB or GB
• To determine the storage capacity your system
needs, calculate the amount of storage capacity
basic computer programs need to reside on your
computer
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The Hard Disk Drive
• Sample Hard Drive Requirements
Application
Hard Disk Space Required
Windows Vista Home Basic
512 MB
MS Office Pro 2007
256 MB
Internet Explorer 7
128 MB
iTunes
256 MB
Microsoft Picture It!
128 MB
Total Required
1,768 MB (1.77 GB)
(If running all programs
simultaneously)
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The Hard Disk Drive
• There are several types of hard drives
– Integrated Drive Electronics (IDE)
• An older style that used wide cables to connect the
hard drive to the Motherboard
• Also called PATA – Parallel Advanced Technology
Attachment
– Serial Advanced Technology Attachment (ATA)
• Use much thinner cables
• Can transfer data more quickly than IDE drives
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Portable Storage
• Gives us the ability to move data
from one computer to another
• Types of portable storage devices:
– Floppy disk:
• Capacity 1.44 MB
• Computer makers have stopped
shipping floppy drives as standard
equipment
– Zip disk:
• Capacity 100 MB to 750 MB
– CD-R, CD-RW, DVD-R, DVD-RW:
• Capacity 700 MB to 9.4 GB
– Flash drive:
• Capacity up to 4 GB
– Flash memory Card:
• Up to 16 GB (and up)
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Magnetic Storage
• Magnetic media:
– Metal platters:
Track
• Hard disks
– Plastic film:
• Floppy disks
• Zip disks
Sector
• Tracks
• Sectors
• File Allocation Table
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Magnetic Storage
• Inside the plastic cases of both floppy and
Zip disks, you’ll find a round piece of
plastic film
• This film is covered with a magnetized
coating of iron oxide
• Like a hard drive, when data is saved to
the disk, a pattern of magnetized spots is
created on the iron oxide coating within
the established tracks and sectors
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Magnetic Storage
• Each of these spots represents either a 0
or a 1
– Bit
• When data stored on the disk is retrieved,
your computer translates these patterns of
magnetized spots into information
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Optical Storage
• Optical media:
–
–
–
–
–
–
CD-ROM
CD-R
CD-RW
DVD-ROM
DVD-R
DVD-RW
• Laser
– Pits scatter laser light
equaling a 1
– Nonpitted area reflects
laser light equaling a 0
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Optical Storage
• Like the hard drive, the floppy disk, and zip
disks, data is saved to CDs and DVDs
within established tracks and sectors
• Unlike the hard drive, the floppy disk, and
zip disks, CDs and DVDs store data as tiny
pits that are burned into a disk by a highspeed laser
• These pits are extremely small, less than 1
micron in diameter, so that nearly 1,500
pits fit across the top of a pinhead
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Optical Storage
• Data is read off the CD by a laser beam,
with the pits and nonpits translating into the
1s and 0s of the binary code computers
understand
• Because CDs and DVDs use a laser to read and
write data, they are referred to as optical media
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Optical Storage
• To read information
stored on a disk, a laser
inside the disk drive
sends a beam of light
through the spinning
disk.
– If the light reflected back
is scattered in all
directions (which happens
when the laser hits a pit),
the laser translates this
into the binary digit 0.
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Optical Storage
– If non-scattered light is
reflected back to the laser
(which happens when the
laser hits an area in which
there is no pit), the laser
translates this into the
binary digit 1.
• In this way, the laser
reads the pits and nonpits as a series of bits
(0s and 1s), which the
computer can process.
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Optical Storage
• CD-ROMs are prerecorded and cannot be
written to
• CD-Rs are blank and can be written to or
burned once with a CD rewritable drive
• CD-RWs start blank but can be rewritten or
reburned several times
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Optical Storage
• DVD-ROM, DVD-R, and DVD-RW follow
the same pattern but at much higher
capacities
• DVD’s (Digital Video Discs) storage
capacity is much greater than CD’s
• DVDs have less space between tracks, as
well as between bits
• The size of pits on the DVD is also much
smaller than those on a CD
• Additionally, DVD audio and video quality is
superior to that of a CD
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Optical Storage
• DVDs can have data on just one side or
both sides of the disc with one or two layers
on each side for a maximum capacity of
17GB per disc
• The DVD’s main competitor appears to be
the HD-DVD (High-Definition DVD), which
holds less data but may be cheaper to
produce
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Optical Storage
• Blu-Ray is one new emerging standard of
data storage
– The “blue” in the name refers to the fact that a
blue laser, instead of a red laser, is used to
write and read these discs
• A single layer Blu-Ray disc can hold 25 GB
of data
• A double-layer disc can hold 50 GB
– Four hours of high-definition video
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Optical Storage
• Experiments are underway using
fluorescent optical discs that can store data
in as many as 100 different layers, for a
final capacity of 450 GB
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Optical Storage
• CD drives cannot read DVDs. DVD drives
can read CDs
• To record data to DVDs, you need
recordable DVD discs and a read/write
DVD drive
• There are two recognized formats
– DVD-R/RW
• DVD Dash
– DVD+R/RW
• DVD Plus
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Optical Storage
• Either the Plus or Dash format discs you
write will be compatible in about 85% of all
DVD players
• You must make sure, however, to purchase
blank DVD discs that match the type of
drive you own
• Either type of DVD burner can burn CDs
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Optical Storage
• When you buy a CD or VD drive, knowing
the drive speed is important
• Speeds are listed on the device’s
packaging
– Record (write) speed is always listed first
– Rewrite speed is listed second
– Playback speed is listed last
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Optical Storage
• A CD-RW drive may have the following
speeds of 52X32X52X
– Record data at 52X speed
– Rewrite data at 32X speed
– Play back data at 52X speed
• A 1x DVD-ROM drive provides a data
transfer rate of approximately 1.3 MB of
data per second
– Roughly the equivalent to a CD-ROM speed of
9X
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Storage
• Portable Storage Capacities
Storage Media
Capacity
Floppy Disk
1.44 MB
Zip Disk
100 To 750 MB
CD
700 MB
DVD
9.4 GB
Flash Memory
512 MB to 16 GB (and up)
Portable Hard Drive
20 GB and up
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Upgrading Storage
• Hard drive options:
– Replace current drive with
a larger capacity drive
– Install an additional hard
drive in your current
system if you have an extra
drive bay
– Use an external hard drive
you can plug into a USB or
FireWall port
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Upgrading Storage
• Other options:
– Zip drive
– Replace CD ROM with
CD-R/RW or DVD-R/RW
• Need an open bay
– Without open bays, you
can add external Zip and
CD/DVD drives that attach
to your computer through
an open port
– Flash card reader
• Need a Memory Card Reader
– Flash memory drive
• Plug directly into a USB port
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Evaluating Video
• How video is
displayed depends on
two components:
– Video card (adapter)
– Monitor
• It’s important that
your system have the
correct monitor and
video card to meet
your needs
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Video Cards
• An expansion card that is
installed inside your
system unit to translate
binary data into the
images you view on your
monitor
• Include ports allowing you
to connect to different
video equipment
• Contain their own RAM
– Video RAM (VRAM)
• Some come with their own
processors which
significantly speeds up
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processing
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Video Cards
• Contain their own RAM
– Video RAM (VRAM)
– If you only work with
Microsoft Word and conduct
general Web searches, 16
MB is a realistic minimum
– For the serious gamer, a
256-MB card is essential
– Cards with 512 MB are on
the market today
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Video Cards
• Some come with their own
processors
– Calls to the CPU for
graphics processing are
redirected to the processor
on the video card which
significantly speeds up
processing
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Video Cards
• Controls the number of colors a monitor
can display
• The number of bits the video card uses to
represent each pixel (or dot) on the monitor
(bit depth) determines the color quality of
the image displayed
• The more bits, the better the color detail of
the image
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Video Cards
• A 4-bit video card displays 16 colors
– The minimum number of colors your system
works with
– Standard VGA
• Most video cards today are 24-bit cards,
displaying more than 16 million colors
– True Color Mode
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Video Cards
• Bit Depth and Color Quality
Bit Depth
Color Quality
Description
Number of Colors
Displayed
4-bit
Standard VGA
16
8-bit
256-Color Mode
256
16-bit
High Color
65,536
24-bit
True Color
16,777,216
32-bit
True Color
16,777,216 plus 8 bits to
help with transparency
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Monitors
• Things to consider:
– Types:
• CRT or LCD
– Size:
– 15, 17, 19, or 21 inch
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Monitors
• Resolution
– Increasing resolution allows more to be
displayed
– Increased resolution also makes the images on
the screen smaller and perhaps more difficult
to read
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Monitors
• Dot pitch
– The diagonal distance between pixels of the
same color on the screen
• For a clearer, brighter image, look for a monitor with
a low dot pitch of
– No more than 0.28 mm for a 17-inch screen
– 0.31 mm for a 21-inch screen
• Refresh rate
– The number of times per second the
illumination of each pixel on the monitor is
recharged
•
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75 Hz or higher
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Evaluating Audio
• Sound card:
– Attach to the Motherboard
– Process digital data into
sounds
– Most computers ship
with a basic sound card
• 3D sound cards
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Evaluating Audio
• Stereo sound allows the human ear to
perceive sounds as coming from the left or
the right of the performance area
• 3D sound is better at convincing the human
ear that sound is omnidirectional
– You can’t tell from which direction the sound is
coming
– This tends to produce a fuller, richer sound
than stereo sound
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–
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Inc. 3D sound is not surround sound
Evaluating Audio
• Surround sound
– The current surround sound standard is Dolby
7.1 Format
– The 7.1 format takes digital sound from a
medium and reproduces it in eight channels
– To set up surround sound on your computer,
you need
• A set of surround-sound speakers
• A sound card that is Dolby 7.1 compatible
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Evaluating Audio
• Speakers:
–
–
–
–
Amplified
Not amplified
Subwoofer
Surround sound
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Evaluating Ports
• Ports are used to connect peripheral
devices to the computer
• Things to consider:
– Devices you want to use
– Ports needed for your peripheral devices
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Types of Ports
• Serial Port
– Transfers data one
bit at a time at
speeds up to 56
kbps
– Mice
– External modems
• Slowly being phased
out by USB ports
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PS/2 Port
COM 1 Port
PS/2
Connectors
Serial
Connector
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Types of Ports
• Parallel Port
– Transfers eight
LPT 1 Port
bits of data
simultaneously
Printer Cable Connector
– 12 Mbps
– Printers, Scanners
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Types of Ports
• Universal serial bus
– Transfer speed up to
480 Mbps
• Version 1 – 12 Mbps
• Version 2 – 480 Mbps
USB
Port
USB
Connector
– Becoming the most
common port
– Mice, keyboards, external zip drives,
© 2008 Prentice-Hall, Inc. printers, scanners, game controllers 73
Types of Ports
• FireWire
– Transfer rate of
400 Mbps; Digital
cameras
– Newer FireWire
800 is fastest
FireWire
Port
FireWire
Connector
• Available only on
the Apple Mac
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Types of Ports
• Ethernet
– Transfer rate of 100
Mbps;
– Connects computers
to networks
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Ethernet
Port
Ethernet
jack
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Types of Ports
• IrDA
– Transfer rate of 4
Mbps;
– Uses infrared light
waves
– Requires a line of
sight
IrDA
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Types of Ports
• Bluetooth
– Transfer rate of 1
Mbps
– Bluetooth 2 has a
transfer rate of 3
Mbps
– Uses radio waves
to send data over
short distances
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Bluetooth
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Types of Ports
• MIDI Port
– Musical Instrument Digital Interface
– 31.5 Kbps transfer rate
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Adding Ports
• Expansion cards:
– New port
standards
• Expansion hubs:
– Enables several
devices to be
connected to a
port
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Evaluating System Reliability
• Performance:
– Slow
– Freezes
– Crashes
• Upkeep and maintenance:
– System tools
– Control panel
– Update software and hardware
drivers
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Upkeep and Maintenance
• System tools:
– Disk defragmenter
– Disk cleanup
• Unnecessary files
• Control panel:
– Add/remove
programs
– Display
– System
• Device manager
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Update Software and
Hardware Drivers
• Software:
– Automatic
updates
– Patches
• Hardware:
– Download
updated drivers
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The Last Resort
• If problems persist:
– Reinstall the operating system
– Upgrade the operating system to the latest
version
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The Final Decision
• How closely does your system come to
meeting your needs?
• How much would it cost to upgrade your
system?
• How much would it cost to purchase a new
system?
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Chapter 6 Summary Questions
• How can I determine whether I should
upgrade my existing computer or buy a
new one?
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Chapter 6 Summary Questions
• What does the CPU do and how can I
evaluate its performance?
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Chapter 6 Summary Questions
• How does memory work and how can I
evaluate how much memory I need?
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Chapter 6 Summary Questions
• What are the computer’s main storage
devices and how can I evaluate whether
they match my needs?
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Chapter 6 Summary Questions
• What components affect the output of
video and how can I evaluate whether they
are meeting my needs?
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Chapter 6 Summary Questions
• What components affect the quality of
sound and how can I evaluate whether
they are meeting my needs?
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Chapter 6 Summary Questions
• What are the ports available on desktop
computers and how can I determine what
ports I need?
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Chapter 6 Summary Questions
• How can I ensure the reliability of my
system?
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