Computer Hardware

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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

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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
• 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

• Decide how your computer will be used, and how
  much you want to spend
• Decide on a platform (Mac, PC, Linux)
• Look at ads in computer magazines and at
  computer/electronic stores
• Understand the computer jargon
• Expect to pay anywhere from a few hundred to
  several thousand dollars

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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
• Todays Microprocessors
• Random Access Memory
• Read-only Memory
• EEPROM

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Microprocessor Basics

• Microprocessor clock
• Megahertz
• Gigahertz
• Cache
• Level 1 cache (L1)
• Level 2 cache (L2)

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Todays 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
• 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
  computers 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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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

• Todays 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
• DVDR or DVD-R
• CD-RW
• DVDRW 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 computers USB port
  using a built-in connector

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Storage Wrap-up
Most desktop computers have several drive bays,
some accessible from outside the case, and
othersdesigned for hard disk driveswithout
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 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 bigger is better
• Dot pitch smaller is better
• Refresh rate higheris better
• Color depth how many colors can be displayed
• 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
• Print speed (per minute)
• Duty cycle (per month)
• Operating costs

• Duplex capability 1 or 2 sides
• Memory
• Networkability

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Installing Peripheral Devices

• 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
• PCMCIA 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 yourselfthats 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

• Surge Protection and Battery Backup
• Basic Maintenance
• Troubleshooting and Repair

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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.
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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
• Help and Support Center
• Safe Mode

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Troubleshooting and Repair
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Chapter 2 Complete

• Computer Hardware