Chapter 3 PowerPoint

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Computer Hardware

Chapter 3

Copyright © 2010 by the McGraw
-
Hill Companies, Inc. All rights reserved.

McGraw
-
Hill/Irwin

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2

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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3

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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Pre
-
Computer Calculations


Counting on fingers and toes


Stone or bead abacus


Calculate comes from calculus,

the Latin word for small stone


1642: first mechanical adding machine


Invented by Blaise Pascal, wheels moved counters


Modified in 1674 by Von Leibnitz


Age of industrialization


Mechanical loom used punch cards

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Early Computing


19th Century


Charles Babbage proposed the Analytical
Engine, which could calculate, store values

in memory, perform logical comparisons


Never built due to of lack of electronics


1880s


Hollerith’s punched cards used to record
census data using On/Off patterns


The holes turned sensors On or Off when

run through tabulating machine


This company became the foundation for IBM

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Electronic Computers


1946
-

First Generation Computer


ENIAC


Programmable


5000 calculations per second


Used vacuum tubes


Drawbacks were size and processing ability


1950s


ENIAC replaced by UNIVAC 1, then IBM 704


Calculations jumped to 100,000 per second

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Waves of Computing


Late 1950s
-

Second Generation


Transistors replaced vacuum tubes


200,000 to 250,000 calculations per second


Mid
-
1960s
-

Third Generation


Integrated circuitry and miniaturization


1971
-

Fourth Generation


Further miniaturization, multiprogramming,

virtual storage


1980s
-

Fifth Generation


Millions of calculations per second


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8

Microcomputers


1975


ALTAIR, programmed by flicking switches


1977


Commodore & Radio Shack produce PCs


1979


Apple computer, the fastest selling PC thus far


1982


IBM introduced the PC, which changed the
market

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Categories of Computer Systems

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Microcomputer Systems

Computing power now exceeds that of the
mainframes of previous generations

Called a personal computer or PC

Relatively inexpensive

Hand
-
held, notebook, laptop, tablet,
portable, desktop, and floor
-
standing

Networked professional workstations
used by businesses

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Recommended PC Features

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Microcomputer Uses

Workstations

Supports heavy
mathematical
computer and
graphics display
demands

CAD, investment,

and portfolio analysis

Network Servers

More powerful than
workstations

Coordinates
telecommunications
and resource sharing

Supports small
networks and Internet
or intranet websites

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Microcomputer Uses


Terminals


Any device that allows

access to a computer


Types


Dumb


Intelligent

(Windows or Internet)


Transaction

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Corporate PC Criteria


Solid performance at a reasonable price


Operating system ready


Connectivity


Security
-
equipped

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Information Appliances


Hand
-
held microcomputer devices


Known as personal digital assistants (PDAs)


Web
-
enabled PDAs use touch screens,

handwriting recognition, or keypads


Mobile workers use to 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

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Midrange Systems


High
-
end network servers that handle large
-
scale
processing of business applications


Not as powerful as mainframes


Less expensive to buy, operate, maintain


Often used to manage


Large Internet websites, intranets, extranets


Integrated, enterprise
-
wide applications


First became popular as minicomputers


Used as front
-
end servers


Assists 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 a popular computing platform for…


Data mining, warehousing, electronic commerce
applications

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Supercomputer Systems


Extremely powerful systems designed for…


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)

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The Next Wave of Computing

Harnessing the infinite amount of unused
computing power

Desktops and laptops within an organization

Distributed or grid computing

Parallel computing that relies on complete
computers connected to a network

Harnesses the unused CPU power in all connected
computers, even between organizations

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Computer System Concept

System of

hardware devices

organized by

function

Input

Processing

Output

Storage

Control

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Computer System Concept

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Computer Processing Speeds


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)


Commonly called “clock speed”

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Computer Processing Speeds


Throughput


Ability to perform useful computation or data
processing assignments during a given period


Speed is dependant on…


Size of circuitry paths (buses) that

interconnect microprocessor components


Capacity of instruction processing registers


Use of high
-
speed cache memory


Use of specialized microprocessors, such

as math coprocessor

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Moore’s Law

Doubling of the number of transistors

per integrated circuit every 18 to 24 months

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Peripherals

Separate from, and not under the
control of, the CPU

Offline Devices

Separate from the CPU, but
electronically connected to (and
controlled by) it

Online Devices

Generic name for all input, output,
and secondary storage devices

Peripheral

Parts of the computer system (not
the CPU)

All online devices

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Peripherals Advice

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27

Input Technologies


Common input devices


Keyboard


Graphical User Interface
(GUI)


Electronic mouse

and trackball


Pointing stick


Touchpad


Touchscreen

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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 Systems


Speech may be the future of data entry


Easiest, most natural means of human
communication


Recognizing speech patterns


Discrete, requires pauses between each word


Continuous speech recognition software (CSR)
recognizes continuous, conversationally paced
speech

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Speech Recognition Software


Speech recognition systems digitize, analyze,
and classify speech and sound patterns


Compares to a database of sound patterns


Passes recognized words to software


Typically requires voice recognition training


Speaker
-
independent systems


Allow computers to recognize words from a
voice never heard before


Typically used in voice
-
messaging computers

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Optical Scanning


Devices read text or graphics and convert them into
digital computer input


Enables direct entry of data from source documents


Document management library system


Scans documents, then organizes and stores them

for easy reference or retrieval

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Optical Scanning

Scanners

Optical Character Recognition (OCR)

Compact desktop models
are popular for low

cost and ease of use

Larger, more expensive
flatbed scanners are

faster, offer high
-
resolution
color scanning

Software that reads
characters and codes

Used to read merchandise
tags, sort mail, score tests,
read bar codes

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Other Input Technologies

Magnetic Stripe

Magnetic Ink Character

Recognition (MICR)

Digital Cameras

Smart Cards

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Output Technologies

Voice Response

Increasingly found along with
video displays in business
applications

Video Displays

Cathode
-
ray tube (CRT)

Printed Output

Inkjet and laser

Liquid crystal display (LCD)

Plasma displays

(TVs, flat
-
panel monitors)

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Storage Tradeoffs

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Computer Storage Fundamentals

On (1) or Off (2)

Data processed & stored in computer
systems through On/Off signals

Uses two
-
state
(binary) data
representation

Smallest element of data

Either zero or one

Bit

Group of eight bits, which operate


as a single unit

Represents one character or number

Byte

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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 (Random) and Sequential Access

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Semiconductor Memory


Microelectronic semiconductor memory chips
are used for primary storage


Advantages
: small size, fast, shock and
temperature resistance


Disadvantages
: volatility; must have
uninterrupted electric power or loses memory

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Types of Semiconductor Memory

Random Access
Memory (RAM)

Read
-
Only Memory
(ROM)

1. Most widely used
primary storage
medium

2. Volatile memory

3. Read/write memory

1. Permanent storage

2. Can be read, but not
overwritten

3. Frequently used
programs burnt into
chips during
manufacturing

4. Called firmware

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Flash Drives


Sometimes called a
jump drive


Uses a small chip containing

thousands of transistors


Can store data for virtually

unlimited periods without power


Easily transported


Highly durable


Storage capacity of up to 20 GB


Plugs into any USB port

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Magnetic Disks


Used for secondary storage


Fast access and high capacity


Reasonable cost

Hard Disk Drives & Floppy Disks (diskettes)

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RAID Storage


Redundant Arrays of Independent Disks


Provides virtually unlimited online storage


6 to more than 100 hard disk drives are
combined into a single unit


Data is 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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Uses of Optical Disks

Image Processing

Long
-
term storage of

historical image files

Storage of scanned documents

Publishing
Medium

Allows fast access to

reference materials

Catalogs, directories, and so on

Interactive
Multimedia
Applications

Video games, educational videos,
and so on

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Radio Frequency Identification (RFID)


One of the newest, fastest growing storage
technologies


System for tagging and identifying mobile objects


Used with store merchandise, postal packages,

casino chips, pets


Special reader allows objects to be tracked as

they move from place to place


Chips half the size of a grain of sand


Passive chips derive power from reader signal


Active chips are self
-
powered

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RFID Versus Bar Coding

Invisible nature of the system

Capacity to transmit fairly sophisticated
messages

Privacy
Concerns

Scans from greater distance

Can store data

More information can be tracked

RFID