copyright 2003 the mcgraw-hill companies, inc. 1 66 chapter the system unit computing essentials
TRANSCRIPT
Copyright 2003 The McGraw-Hill Companies, Inc.
1
6666CH
AP
TE
R
The System Unit
computing ESSENTIALS
Copyright 2003 The McGraw-Hill Companies, Inc.
2
Competencies
System Clock
Cards and buses
Ports and cables
computing ESSENTIALS
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System Clock
Special chip that produces precise
electrical impulses
Used to coordinate and synchronize
computer operations
Expressed in megahertz or gigahertz
Faster clock speed, faster computer
computing ESSENTIALS
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4
Expansion Slots and Cards
An expansion slot is a long, narrow socket on the motherboard into which an expansion card can be inserted.
Expansion cards act like an interface circuit for a computer peripheral device.
These cards provide the computer an ability to control a peripheral device (input or output).
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5
Expansion Cards
Expansion cards used to connect to devices
outside the system unit
Controller cards, Adapter cards, Interface cards,
plug-in boards
Usually have ports to connect the card to a
device outside the system unit
computing ESSENTIALS
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Types of Expansion Cards
Network interface cards (NIC)
Modem cards Sound cards Video cards SCSI adapter TV tuner cards PCMCIA cards
computing ESSENTIALS
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Card Configuration Settings
For installing a new device, following setup is needed: Inserting the device card into the matching slot Installing the device driver program for the device Configure the system (tedious step, requires
sufficient technical background)
“Plug and Play” is a new technology for making the device installation procedure much faster and easier.
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“Plug and Play”
Hardware and software standards
Makes system expansion easy
for the user
Automatically installs drivers and
system configuration
System unit recognizes the new
device
computing ESSENTIALS
A plug-n-play card requires the user to:
•Switch off the system
•Insert the card
•Open the system again.
•System automatically configure itself for the newly installed device
-User is asked for the latest device driver.
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9
Bus Lines
More lines, the faster data can travel 64 bit data bus is
faster than a 32 bit Data pathways that
link parts of the CPU together and components to the CPU
computing ESSENTIALS
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Principal Bus Architectures
Industry Standard Architecture (ISA)
Peripheral Component Interconnect (PCI)
Advanced Graphic Port (AGP)
Universal Serial Bus (USB)
High performance Serial Bus (HPSB)
computing ESSENTIALS
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ISA Bus
Developed by IBM for personal computers
Slow
Originally 8 bit, later expanded to 16 bit
Still used by some expansion cards
Replaced by PCI bus in the near future
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12
PCI Bus
Originally developed to meet demands of
graphical user interfaces
High speed
32 bit or 64 bit
Widely used to connect CPU, memory, and
expansion cards
computing ESSENTIALS
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13
AGP Bus
Dedicated bus for acceleration of graphics
performance
Replacing the PCI bus for transfer of video data
computing ESSENTIALS
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14
Other Bus Types
USB Connects directly to the PCI bus on the
motherboard Supports external devices without inserting
expansion cards for each device HPSB
FireWire Similar to USB but faster
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Ports
Four common port types Serial Parallel USB FireWire
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Sockets that connect external devices to the system unit
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Serial & Parallel Ports
Serial Port
Data sent one bit at a time
Good long distance transmission of data
Parallel Port
Data sent 8 bits simultaneously
Used for short distances
computing ESSENTIALS
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17
USB and HPSB Ports
USB Port Replacing serial and parallel ports Faster Each port can support
more than one device HPSB Port
FireWire ports Faster then USB ports
computing ESSENTIALS
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18
Cables
Connect Input/Output devices Mouse Keyboard Printer Monitor
Newer cables AGP
graphics monitor USB
joy stick; scanner HPSB
video camera
computing ESSENTIALS
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19
Look to the Future
Wireless Technology and PDAs Personal wearable computer
POMA®
Wireless pointing device, head mounted display
Developed by Xybernaut Corporation
Currently being evaluated for use in airport security
computing ESSENTIALS