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