Transcript Chap003_000

Chapter
3
Computer Hardware
McGraw-Hill/Irwin
Copyright © 2011 by The McGraw-Hill Companies, Inc. All rights reserved.
Learning Objectives
• Understand the history and evolution of
computer hardware.
• Identify the major types and uses of
microcomputer, midrange, and
mainframe computer systems.
• Outline the major technologies and uses
of computer peripherals for input, output,
and storage.
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Learning Objectives
• Identify and give examples of the
components and functions of a computer
system.
• Identify the computer systems and
peripherals you would acquire or
recommend for a business of your choice,
and explain the reasons for your selection.
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RWC 1: Do You Know What You’ve Got?
• Astra Zeneca
– Multiple acquisitions with non-standard IT systems
– PS’Soft asset Management
• Conducted life-cycle studies
• Gained leverage with vendors
• United Health Group
– Unnecessary IT diversity
– Hercules desktop management standardizes:
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Procurement
Configuration
Installation
Life-cycle
Asset management
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Early Computing
• 1880s
– Punched cards turned sensors On or Off
• 1946
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ENIAC
First Digital computer - programmable
Used vacuum tubes
Would fill room 39 ft by 39 ft
• Late 1950s
– Transistors replaced vacuum tubes
– Smaller, faster, cooler
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Waves of Computing
• First Generation - Prior to 1950
– Vacuum tubes
• Second Generation - Late 1950s
– Transistors & integrated circuits – Jack Kilby
– 200,000 to 250,000 calculations per second
• Third Generation - Mid-1960s
– Integrated circuitry and miniaturization
• Fourth Generation - 1971
– Further miniaturization
– Multiprogramming and virtual storage
• Fifth Generation - 1980s
– Millions of calculations per second
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Age of Microcomputers
• 1975
– MITS introduced ALTAIR 8800.
• 1977
– Commodore and Radio Shack
• 1979
– Apple computer, fastest selling
– Steve Jobs & Steve Wozniak
• 1982
– IBM introduced the PC
– Changed the market
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Categories of Computer Systems
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Recommended PC Features
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Corporate PC Criteria
• Solid performance, reasonable price
• Operating system ready
• Connectivity
– Network interface cards
– Wireless capabilities
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Information Appliances
• Hand-held microcomputer devices
• Known as personal digital assistants (PDAs)
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Web-enabled
Touch screens, handwriting recognition, keypads
Access email or the Web
Exchange data with desktop PCs or servers
Latest entrant is the BlackBerry
• PDAs include
– Video-game consoles
– Cellular and PCS phones
– Telephone-based home email appliances
• iPhone 4
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Midrange Systems
• High-end network servers
– Large-scale processing of business applications
• Not as powerful as mainframes
– Less expensive to buy, operate, and maintain
• Often used to manage
– Large Internet websites
– Corporate intranets and extranets
– Integrated, enterprise-wide applications
• Used as front-end servers
– Assist mainframes with telecommunications and
networks
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Mainframe Computer Systems
• Large, fast, powerful computer systems
– Large primary storage capacity
– High transaction processing
– Handles complex computations
• Widely used as superservers for…
– Large client/server networks
– High-volume Internet websites
• Becoming popular computing platform for…
– Electronic commerce applications
– Data mining and warehousing
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Supercomputer Systems
• Extremely powerful systems
– Scientific, engineering, and business applications
– Massive numeric computations
• Markets include…
– Government research agencies
– Large universities
– Major corporations
• Uses parallel processing
– Billions to trillions of operations per second
• (gigaflops and teraflops)
– Costs $5 to $50 million
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Computer System Concept
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Computer Processing Speeds
• Commonly called “clock speed”
• Early computers
– Milliseconds (thousandths of a second)
– Microseconds (millionths of a second)
• Current computers
– Nanoseconds (billionth of a second)
– Picoseconds (trillionth of a second)
• Program instruction processing speeds
– Megahertz
– Gigahertz
(millions of cycles per second)
(billions of cycles per second)
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Moore’s Law
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RWC 2: Voice Recognition Tools
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Doctors record to e-medical records
Nurses receive instructions record actions
Time cut by 75 percent
Reduced mistakes
ROI 12 to 18 months
Transcription $500,000 to zero
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Peripherals Advice
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Input Technologies
• Keyboard
• Graphical User Interface (GUI)
• Electronic Mouse
• Trackball
• Pointing stick
• Touchpad
• Touch screen
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Pen-Based Computing
• Used in Tablet PCs and PDAs
– Pressure-sensitive layer, similar
to touch screen, under liquid
crystal display screen
– Software digitizes handwriting,
hand printing, and hand drawing
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Speech Recognition Software
• Digitize, analyze, and classify speech and
sound patterns
– Compares to sound patterns in its vocabulary
– Passes recognized words to the application
software
• Speaker-independent voice recognition
systems
– Recognizes words from never heard voice
– Voice-messaging computers
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Optical Scanning
• Converts text or graphics to digital
• Document management library system
• Scanners
• Optical Character Recognition (OCR)
– Reads characters and codes
– Optical scanning wands
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Other Input Technologies
• Magnetic Stripe on credit cards
• Smart Cards
• Digital Cameras
• Magnetic Ink Character Recognition (MICR)
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Output Technologies
• Video Displays
– Cathode-ray tube (CRT)
– Liquid crystal displays (LCDs)
– Plasma displays
• Printed Output
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Dot matrix
Character printers
Inkjet printers spray ink
Laser printers
• Electrostatic process
• Similar to a photocopying machine
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Storage Tradeoffs
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Representing Characters in Bytes
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Using Binary Code to Calculate
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Storage Capacity Measurement
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Kilobyte (KB): one thousand bytes
Megabyte (MB): one million bytes
Gigabyte (GB): one billion bytes
Terabyte (TB): one trillion bytes
Petabyte (PB): one quadrillion bytes
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Direct and Sequential Access
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Types of Semiconductor Memory
• Random Access Memory (RAM)
– Most widely used primary storage medium
– Volatile memory
– Read/write memory
• Read-Only Memory (ROM)
– Permanent storage
– Can be read, but not overwritten
– Frequently used programs burnt into chips
during manufacturing process
– Called firmware
• Flash Drive
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Flash Drives
• Jump drive, travel drive, etc.
– Small chips thousands of transistors
– Stores data virtually unlimited periods without
power
– Easily transported and highly durable
– Storage capacity of up to 20 GB
• New 1 TB
– Plugs into any USB port
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Direct Access – Magnetic Disk
• Used for secondary storage
– Fast access and high capacity
– Reasonable cost
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RAID Storage
• Redundant Arrays of Independent Disks
– Arrays of hard disk drives
– Virtually unlimited online storage
– 6 to more than 100 small hard disk drives in a
single unit
– Data are accessed in parallel over multiple
paths from many disks
– Redundant storage of data on several disks
provides fault-tolerant capacity
– Storage area networks can interconnect many
RAID units
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Magnetic Tape
• Secondary storage
– Tape reels, cassettes, and cartridges
– Used in robotic, automated drive assemblies
– Archival and backup storage
– Lower-cost storage solution
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Optical Disks
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Radio Frequency Identification (RFID)
• One of the newest and fastest growing
storage technologies
– System for tagging and identifying moving objects
• Merchandise, postal packages, casino chips, pets
– Tag 1 inch square
– Chips half the size of a grain of sand
• Passive chips derive power from reader signal
• Active chips are self-powered
• Privacy Issues
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Predictions for the Future
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Biological memories
Health remedies
Longer life spans
Virtual activities
Memory recall
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RWC 3: Grid Computing
• Grid computing
– Tapping into available computer power on other
systems
– Better use of underutilized hardware
– Avoid dedicated hardware costs
• Cancer Institute in New Jersey
– Convert hundreds of thousands of images of
cancerous tissues and cells into digital images.
– Check accuracy
– Diagnose and treat cancer patients faster and with
more success.
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RWC 4: Touch Screen Comes of Age
• The WIMP - Windows, Icons, Menus, and
Pointing devices dominated for 15 years.
• New human interface technologies
revolutionize interaction with computers.
• Microsoft and Starwood Hotels & Resorts
introduce surface computing
• Gesture recognition is logical extension of
touch technology
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