Chapter 2
Computer Hardware
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Chapter Contents
• Section A: Personal Computer Basics
• Section B: Microprocessors and Memory
• Section C: Storage Devices
• Section D: Input and Output Devices
• Section E: Hardware Security
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Personal Computer Basics
• Personal Computer Systems
• Desktop and Portable Computers
• Home, Media, Game, and Small Business
Systems
• Buying Computer System Components
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Personal Computer Systems
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Desktop and Portable Computers
• The term form factor
refers to the size and
dimensions of a
component, such as a
system board or
system unit
• A desktop computer
fits on a desk and
runs on power from
an electrical wall
outlet
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Desktop and Portable Computers
• A portable computer is a small, lightweight
personal computer
• A notebook computer (also referred to as a
laptop), is a small, lightweight portable computer
that opens like a clamshell to reveal a screen
and keyboard
• A tablet computer is a portable computing device
featuring a touch-sensitive screen that can be
used as a writing or drawing pad
• An ultra-mobile PC (UMPC) is a small form
factor tablet computer designed to run most of
the
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computers
Desktop and Portable Computers
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Home, Media, Game,
and Small Business Systems
• A home computer system offers a hardware
platform with adequate, but not super-charged
support for most computer applications
• A Media Center PC includes components for
integrating computers, televisions, home
theaters, and audio systems
• Some of the most cutting-edge computers are
designed for gaming
• Computers marketed for small business
applications tend to be middle-of-the-line models
pared down to essentials
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Buying Computer
System Components
• Browse through computer magazines and online
computer stores to get a general idea of features
and prices
• Decide on a budget and stick to it
• Make a list of the ways you plan to use your
computer
• Select a platform
• Decide on a form factor
• Select peripherals, software, and accessories
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Buying Computer
System Components
• Instead of buying a new computer, you
might consider upgrading
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Microprocessors and Memory
• Microprocessor Basics
• Today’s Microprocessors
• Random Access Memory
• Read-only Memory
• EEPROM
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Microprocessor Basics
• A microprocessor is an integrated circuit
designed to process instructions
– Most expensive component
of a computer
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Microprocessor Basics
• Front side bus
– HyperTransport
• Microprocessor clock
– Megahertz
– Gigahertz
• Word size
• Cache
– Level 1 cache (L1)
– Level 2 cache (L2)
• CISC vs. RISC
technology
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Microprocessor Basics
• Serial processing
– Pipelining
• Parallel processing
• Multi-core processor
• Hyper-Threading Technology
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Today’s Microprocessors
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Random Access Memory
• Random Access Memory is a temporary
holding area for data, application program
instructions, and the operating system
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Random Access Memory
• Microscopic capacitors hold the bits that
represent data
• Most RAM is volatile
– Requires electrical power to hold data
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Random Access Memory
• RAM capacity is expressed in megabytes
or gigabytes
• Personal computers typically feature
between 256MB and 2GB of RAM
• An area of the hard disk, called virtual
memory, can be used if an application
runs out of allocated RAM
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Random Access Memory
• RAM speed is often expressed in
nanoseconds or megahertz
• SDRAM is fast and relatively inexpensive
– DDR or DDR2
• RDRAM is more expensive, and usually
found in high-performance workstations
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Read-Only Memory
• ROM is a type of memory circuitry that
holds the computer’s startup routine
– Permanent and non-volatile
• The ROM BIOS tells the computer how to
access the hard disk, find the operating
system, and load it into RAM
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EEPROM
• Electrically Erasable
Programmable Read-
Only Memory
• More permanent than
RAM, and less
permanent than ROM
• Requires no power to
hold data
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Storage Devices
• Storage Basics
• Magnetic Disk and Tape Technology
• CD and DVD Technology
• Solid State Storage
• Storage Wrap-up
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Storage Basics
• A storage medium contains data
• A storage device records and retrieves
data from a storage medium
– Data gets copied from a storage device into
RAM, where it waits to be processed
– Processed data is held temporarily in RAM
before it is copied to a storage medium
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Magnetic Disk and
Tape Technology
• Magnetic storage stores data by
magnetizing microscopic particles on the
disk or tape surface
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Magnetic Disk and
Tape Technology
Hard disk platters and read-
write heads are sealed inside
the drive case or cartridge to
screen out dust and other
contaminants.
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Magnetic Disk and
Tape Technology
• A controller positions the disk and read-
write heads to locate data
– SATA
– Ultra ATA
– EIDE
– SCSI
• Not as durable as many other storage
technologies
– Head crash
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Magnetic Disk and
Tape 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
• A tape drive is a device that reads data from and
writes data to a long stream of recordable media
similar to the tapes used in audio cassettes
• A tape is a sequential storage
medium
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CD and DVD Technology
• Optical storage stores data as microscopic
light and dark spots on the disk surface
– CD and DVD storage technologies
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CD and DVD Technology
• Today’s DVD drives typically have 16X
speeds for a data transfer rate of 177.28
Mbps
• Three categories of
optical technologies
– Read-only (ROM)
– Recordable (R)
– Rewritable (RW)
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CD and DVD Technology
• CD-DA
• DVD-Video
• CD-ROM
• DVD-ROM
• CD-R
• DVD+R or DVD-R
• CD-RW
• DVD+RW or DVD-
RW
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CD and DVD Technology
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Solid State Storage
• Solid state storage technology stores data
in an erasable, rewritable circuitry
• Non-volatile
• Card reader may be required
to read data on solid state
storage
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Solid State Storage
• A USB flash drive is a
portable storage device
that plugs directly into a
computer’s USB port
using a built-in connector
• A U3 drive is a special
type of USB flash drive
that is preconfigured to
autoplay when it is
inserted into a computer
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Storage Wrap-up
Most desktop computers have
several drive bays, some
accessible from outside the
case, and others—designed for
hard disk drives—without any
external access. Empty drive
bays are typically hidden from
view with a face plate.
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Storage Wrap-up
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Input and Output Devices
• Basic Input Devices
• Display Devices
• Printers
• Installing Peripheral Devices
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Basic Input Devices
• Keyboard
• Pointing device
– Pointing stick
– Trackpad
– Trackball
– Joystick
• Touch-
sensitive
screen
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Display Devices
• A CRT display device
uses a bulky glass
tube
• An LCD manipulates
light within a layer of
liquid crystal cells
• Plasma screen
technology illuminates
lights arranged in a
panel-like screen
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Display Devices
• Viewable image size
• Dot pitch
• Viewing angle width
• Refresh rate
• Color depth
• Resolution
– VGA, SVGA, XGA, SXGA, UXGA, and
WUXGA
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Display Devices
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Display Devices
• Graphics circuitry generates the signals for
displaying an image on the screen
– Integrated graphics
– Graphics card
– Graphics processing
unit (GPU)
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Printers
• An ink-jet printer has a nozzle-like print
head that sprays ink onto paper
• A laser printer works like a photocopier
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Printers
Laser printers are a popular
technology when high-volume
output or good-quality printouts
are required.
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Printers
• Dot matrix printers produce characters and
graphics by using a grid of fine wires
– The wires strike a ribbon and the paper
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Printers
• Printer features
– Resolution – Duplex capability
– Print speed – Memory
– Duty cycle – Networkability
– Operating costs
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Installing Peripheral Devices
• Many new devices can be connected to an
external USB port
• The data bus moves data within the computer
• Expansion cards are small circuit boards that
give the computer additional capabilities
– Expansion slot
• ISA
• PCI
• AGP
– PC slot
• PC card
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Installing Peripheral Devices
An expansion card simply slides
into an expansion slot and is
secured with a small screw. Before
you open the case, make sure you
unplug the computer and ground
yourself—that’s technical jargon
for releasing static electricity by
using a special grounding wristband
or by touching both hands to a metal
object.
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Installing Peripheral Devices
• An expansion port
passes data in and
out of a computer or
peripheral device
• Peripheral device
may include the Plug
and Play feature, or
require a device
driver
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Installing Peripheral Devices
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Hardware Security
• Anti-theft Devices
• Surge Protection and Battery Backup
• Basic Maintenance
• Troubleshooting and Repair
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Anti-Theft Devices
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Surge Protection
and Battery Backup
• A power surge is a sudden increase or spike in
electrical energy, affecting the current that flows
to electrical outlets
• A surge strip is a device that contains electrical
outlets protected by circuitry that blocks surges
and spikes
• A UPS is a device that not only provides surge
protection, but also furnishes your computer with
battery backup power during a power outage
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Surge Protection
and Battery Backup
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Basic Maintenance
• Computer component failures can be
caused by manufacturing defects and
other circumstances beyond your control
• Keep the keyboard clean
• Clean your computer screen on a regular
basis
• Keep the area clean around your
computer
• Make sure fans are free of dust
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Basic Maintenance
Carefully use a Q-tip and a can
of compressed air or a vacuum
cleaner to remove dust and
debris from your keyboard.
Some liquids are difficult to
remove. That can of pop?
Better to keep it away from
your keyboard.
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Troubleshooting and Repair
• There are several telltale signs that your
computer is in trouble
– Failure to power up
– Loud beep
– Blue screen of death
• Windows Help and Support
• Safe Mode
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Troubleshooting and Repair
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