Transcript Intro to Information Systems

BUSI 240
Introduction to Information Systems
Tuesday & Thursday 8:05am – 9:30am
Wyant Lecture Hall
Please initial the roster on the back table.
3-1
Current Events – What’s going on?
Schwartz On Security: Slouching Toward
Smartphone, Apple Armageddon
Every new year brings fresh warnings that the next
smartphone botnet or Apple "I Love You" virus is imminent,
while real attacks keep escalating.
Smartphones and Apple OS X computers currently draw little
attention from attackers.
Could all that be about to change, as the pace of patches and
improvements in software design make Windows a less juicy
target? We've been hearing this refrain for at least a couple of
years, and I'm still not convinced.
http://www.informationweek.com/news/security/vulnerabilities/showArticle.jhtml?articleID=229100291
3-2
Current Events – What’s going on?
Holocaust historical data goes digital
The world's largest collection of Holocaust documents is going
digital.
Israel's Holocaust memorial, Yad Vashem, is teaming up with
Google to make its photographs and documents interactive and
searchable on the Internet.
The project launched Wednesday with a collection of 130,000
photos that can now be searched directly from Google, using
standard keywords and other data that make it far easier than in
the past to find the desired information.
http://news.yahoo.com/s/ap/20110126/ap_on_hi_te/ml_israel_holocaust_google
3-3
Current Events – What’s going on?
Emotiv's New Mind-Control Headset
for PCs
Its wireless sensors help users run some
programs with their thoughts
What if you could simply think about an
action, and the computer would respond?
http://www.businessweek.com/magazine/content/08_32/b4095000909813.htm
3-4
Current Events – What’s going on?
Automated Theft Machines
One April evening in 2009, a Gray Nissan truck idled in a parking
lot across from a Wachovia Bank in a Fort Lauderdale, Fla.,
suburb. A man wearing sunglasses and a baseball cap hopped
out and walked over to the bank's ATM — but not to withdraw
cash, at least not right away. With practiced ease, he quickly
glued a magnetic-card reader onto the front of the machine, on top
of the ATM's card-reading slot, and swapped out the light panel
above it with one containing a tiny video camera
http://www.time.com/time/magazine/article/0,9171,2041113,00.html#ixzz1CZfZKpEX
3-5
Current Events – What’s going on?
Still patchy
American firms are hiring again, but hold the cheers
WITH the dawn of 2011 America’s recovery is officially longerlived than the recession that preceded it. It is a recovery that
seems to be strengthening, raising hopes that employers will at
last develop an appetite for hiring. America remains over 7m jobs
short of the previous employment peak, and figures published on
January 7th showed that the economy added just 103,000 jobs in
December—scarcely enough to keep up with population growth.
The unemployment rate fell in that month by nearly half a point, to
9.4%, but that was mainly because so many jobless workers gave
up and stopped looking.
http://www.economist.com/research/articlesBySubject/displaystory.cfm?subjectid=348876&story_id=17906059
3-6
Current Events – What’s going on?
3-7
Quiz #1
3-8
Chapter
3b
Computer Hardware
History of computers
Types of computer systems
Hardware components and functions
Computer peripherals
McGraw-Hill/Irwin
Copyright © 2007 by The McGraw-Hill Companies, Inc. All rights reserved.
Current Events – What’s going on?
IBM unveils world's fastest supercomputer
Sequoia, built for the US department of energy, is
almost 20 times more powerful than the previous
record holder
http://www.guardian.co.uk/technology/2009/feb/03/fastest-supercomputer-ibm-sequoia
4-10
IBM Sequoia
4-11
Microcomputer Systems
 Personal
Computer (PC) – microcomputer for use by
an individual
 Desktop
– fit on an office desk
 Laptop – small, portable PC
3-12
Recommended features for PC
3-13
Microcomputer Systems
 Workstation
– a powerful, networked PC for business
professionals
 Network Server – more powerful microcomputers
that coordinate telecommunications and resource
sharing in small networks
3-14
How corporate buyers choose PCs
 Solid
performance at a reasonable price
 Operating system ready
 Connectivity – reliable network interface or wireless
capability
3-15
Terminals
 Devices
that allow access to a network
 Dumb terminals – keyboard and video monitor with
limited processing
 Intelligent terminals – modified networked PCs or
network computers
 Network terminals or computers
 Windows
terminals depend on network servers for
software, processing and storage
 Internet terminals depend to the Internet or Intranet for
operating systems and software
3-16
Information Appliances
 Hand-held
microcomputer devices
 Personal digital assistants (PDA)
 BlackBerry
 Video-game
consoles
 Internet enabled cellular phones
3-17
Midrange systems
 High-end
network servers
 Minicomputers for scientific research and industrial
process monitoring
 Less costly to buy, operate and maintain than
mainframe
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Mainframe Computer Systems
 Large,
fast powerful computer systems
 Large primary storage capacity
 High transaction processing
 Complex computations
 Can
3-26
be used as superservers for large companies
3-27
Supercomputer Systems
 Extremely
powerful systems
 Scientific, engineering and business applications at
extremely high speeds
 Global weather forecasting, military defense
 Parallel processing with thousands of
microprocessors
 Billions of operations per second
 Millions of dollars
 Minisupercomputers
of dollars
3-28
costing hundreds of thousands
Cray 2 Supercomputer
3-29
IBM Supercomputer
3-30
Computer hardware functions


Input
 Keyboards, mice, optical scanners
 Convert data into electronic form
Processing
 Central Processing Unit (CPU)
Arithmetic-logic unit performs the arithmetic functions
 Control unit


3-31
Output
 Video display units, printers, etc.
 Convert electronic information into human-intelligible form
Computer hardware functions
 Storage
 Primary
Storage Unit or memory
 Secondary Storage

Magnetic disks and Optical disks
 Control
 Control
unit of the CPU
 Controls the other components of the computer
3-32
Computer Processing Speeds
 Millisecond
 Microsecond
– millionth of a second
 Nanosecond
– billionth of a second
 Picosecond
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– thousandth of a second
– trillionth of a second
Computer Processing Speeds
 MIPS
– million instructions per second
 Teraflops – trillions of floating point operations per
second (Supercomputer)
 Clock speed of the computer:
 Megahertz
(MHz) – millions of cycles per second
 Gigahertz (GHz) – billions of cycles per second
3-34
Moore’s Law
3-35
Peripherals
 Peripheral
is generic name for all input, output, and
secondary storage devices that are part of the
computer system but are not part of the CPU
 Online devices
 Separate
from CPU
 But electronically connected to and controlled by CPU
 Offline
devices
 Separate
from and not under control of the CPU
 Peripherals
3-36
are online devices
Peripheral Checklist
3-37
Input technologies


3-38
Keyboard: most widely-used
Graphical user interface (GUI)
 Icons, menus, windows, buttons, bars
 Used for selection
Pointing Devices
 Electronic
Mouse
 Trackball – Stationary device like a mouse

Roller ball used to move cursor on screen.
 Pointing
keypad
 Moves
3-39
Stick – Small eraser head-like device in
cursor in direction of pressure placed on stick.
Pointing Devices
 Touchpad
– Small rectangular touch-sensitive surface
 Moves
the cursor in the direction of finger moves on
the pad
 Touch
Screen – use computer by touching screen
 Video
display screen that emits a grid of infrared
beams, sound waves, or a slight electric current
 Grid is broken when the screen is touched.
3-40
Pen-based Computing
 Used in
Tablet PCs and PDAs
 Pressure-sensitive layer like touch screen under
liquid crystal display screen
 Have software that digitizes handwriting, hand
printing, and hand drawing
3-41
Speech Recognition Systems
 Discrete:
pause between each word
 Continuous: conversationally-paced speech
 System
compares your speech patterns to library of
sound patterns
 Training:
to recognize your voice patterns
 Speaker independent system: understand voice never
heard before

3-42
Used in voice-messaging computers
Optical Scanning
 Read
text or graphics and convert them into digital
input
 Desktop or flatbed scanners
 Optical Character Recognition (OCR):
 Read
characters and codes
 Used to read merchandise tags, sort mail, score tests
 Optical
 Read
scanning wands
bar codes such as the Universal Product Code
(UPC)
3-43
Other Input Technologies
 Magnetic
 Read
 Smart
stripe
magnetic stripe on credit cards
cards
 Microprocessor
chip and memory on credit card
 Used more often in Europe than in US
 Digital
cameras
 Magnetic Ink Character Recognition (MICR)
 Identification numbers
of bank and account printed in
magnetic ink on bottom of check
3-44
Output Technologies

Video displays
 Cathode ray tube (CRT) like a television


Liquid crystal displays (LCDs)



Spray ink on page
Laser printer

3-45
Laptop and PDAs, some PCs
Printed Output
 Inkjet printer


Most desktop PC screens
Electrostatic process like photocopying machine
Voice response systems
Storage tradeoffs
3-46
Computer Storage Fundamentals



3-47
Binary representation
 Data are processed and stored in computer system through
the presence or absence of signals
 Either ON or OFF
ON = number 1
OFF = number 0
Bit and Byte


3-48
Bit (short for binary digit)
 Smallest element of data
 Either zero or one
Byte
 Group of eight bits which operate as a single unit
 Represents one character or number
Representing characters in bytes
3-49
Computers use binary system to
calculate
3-50
Measuring storage capacities





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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
Direct and Sequential Access
 Direct
Access or Random Access
 Directly
store and retrieve data
 Each storage position has unique address and can be
accessed in same length of time
 Semiconductor memory chips, magnetic disks
 Sequential
 Data
Access
is stored and retrieved in a sequential process
 Must be accessed in sequence by searching through
prior data
 Magnetic tape
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Direct and sequential access
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Semiconductor memory
 Microelectronic
semiconductor memory chips
 Used for primary storage
 Advantage:
 Small
size
 Fast
 Shock
and temperature resistance
 Disadvantage:
 Volatility:
must have uninterrupted electric power or
lose memory
3-54
Silicon wafer
Each of the rectangles on this earlier silicon wafer is a four-megabit RAM
chip. The wafer is the structural unit that all chips are fabricated on. The
chips are cut out and placed into their individual housings.
3-55
Two types of semiconductor
memory


3-56
RAM: random access memory
 Most widely used primary storage medium
 Volatile memory
 Read/write memory
ROM: read only memory
 Permanent storage
 Can be read but cannot be overwritten
 Frequently used programs burnt into chips during
manufacturing
 Called firmware
Magnetic Disks


Used for secondary storage
Fast access and high storage capacity
Source: Quantum.
3-57
Source: Corbis.
Construction and Operation of the
Hard Disk
3-58
The Difference Between Tracks and
Cylinders
3-59
A platter from a 5.25" hard disk, with
20 concentric tracks drawn over the
surface. Each track is divided into 16
imaginary sectors.
Types of magnetic disks



3-60
Floppy disks
 Magnetic disk inside a plastic jacket
Hard disk drives
 Magnetic disk, access arms, and read/write heads in sealed
module
RAID (Redundant arrays of independent disks)
 Disk arrays of interconnected hard disk drives
 Fault tolerant with multiple copies on several disks
Flash drive





New type of permanent
storage
Uses semiconductor memory
Small chip with thousands of
transistors
Easily transported
Also called jump drives, USB
flash drives
Source: Courtesy of Lexar Media.
3-61
Solid State Drive
Open casing of 2.5” traditional hard disk drive
(left) and solid-state drive (center).
3-62
Current Events – What’s going on?
IBM unveils world's fastest supercomputer
Sequoia, built for the US department of energy, is
almost 20 times more powerful than the previous
record holder
http://www.guardian.co.uk/technology/2009/feb/03/fastest-supercomputer-ibm-sequoia
3-63
Video
 http://www.eweek.com/c/a/Desktops-and-
Notebooks/Solid-State-Drives-Better-for-Users/
3-64
Pros and Cons of SSD
Advantages
• Faster startup (read)
• Faster access to
data/applications (read)
• Constant performance (read)
• No Noise
• Higher mechanical reliability
• Larger range of operating
temperatures
• Lower weight and size
3-65
Disadvantages
• Price
• Capacity
• Vulnerability to abrupt power
loss
• Limited write cycles
• Higher Power Consumption
(overall)
Magnetic Tape
 Secondary
storage
 Tape reels and cartridges
 Used in robotic automated drive assemblies
 Archival storage and backup storage
3-66
Tape Library System
3-67
Optical Disks
3-68
Uses of optical disks
 Image
processing
 Long
term storage of historical files of images
 Scan documents and store on optical disks
 Publishing
materials
 Catalogs,
 Interactive
 Video
3-69
medium for fast access to reference
directories, etc.
multimedia applications
games, educational videos, etc.