computer hardware chapter 3 mcgraw-hill/irwincopyright © 2011 by the mcgraw-hill companies, inc....
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Computer Hardware
Chapter3
McGraw-Hill/Irwin Copyright © 2011 by The McGraw-Hill Companies, Inc. All rights reserved.
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• 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.
Learning Objectives
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• 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.
Learning Objectives
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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:
• Procurement• Configuration• Installation• Life-cycle• Asset management
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Early Computing
• 1880s– Punched cards turned sensors On or Off
• 1946 – 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)
– 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 (millions of cycles per second)– Gigahertz (billions of cycles per second)
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Moore’s Law
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RWC 2: Voice Recognition Tools
• 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– 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
• 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
• 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