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Hardware vs. Software
z Hardware
» The computer equipment
BASIC » Includes printers, monitors, disk drives, etc.
COMPUTER
z Software
CONCEPTS
» Programs which tell the computer what to
do
» Examples - word processing, gradebook,
tutorials, games, etc.
Updated 8/27/04
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History of Computers
z Charles Babbage - father of computer
» 1800’s planned analytical engine
z ENIAC - developed at end of WW II
z 1951 - 1963 1st and 2nd generation
» very large, used unreliable vacuum tubes
z 1963 - present - 3rd and 4th generation
» smaller, faster - use transistors and
integrated circuits
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History - Microcomputers Computer - Social Impact
z Apple z Threat to privacy
» First sold in late 1970’s z Reduce personal interactions
» Developed by Jobs and Wozniak z Displace workers and change workplace
z IBM Personal Computers » Create two tiered society
» First sold in 1981 z Computer failures cause great damage
» Was quickly accepted by businesses
z Artificial Intelligence
» IBM compatibles soon developed
» Create a “new life form”
» Machines smarter than their creators
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Types of Computers – 7
Types of Computers - 8
Personal Computers (PC) Minicomputers
z Also called
Microcomputers z Size of filing cabinet
z Available in desktop
size notebook size and
size,
z Used by small and medium size
handheld companies and institutions
z Can be IBM, IBM
Compatible or Apple z Operated by computer specialist
z Terminals allow many people to use
Types of Computers - 9
Types of Computers- 10
Mainframes Supercomputers
z Very powerful z Most powerful
z Fastest
z Very fast
z Most expensive
z Used by large corporations and » Several million dollars each
governmental agencies z Used only by
» Governmental agencies
z Operated by computer specialist » Large international corporations
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Computer Operations Input Devices - Keyboard
z Most commonly used input device
Input
p Processing
g Output
p z Ergonomic - fit natural hand placement
z Special keys
» Enter, Function, Ctrl, Alt, Num Lock, Esc
External Storage
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Input Devices - Mouse Input Devices - Other
z Controls cursor on
screen z Pointers (replaces mouse on notepads)
» Track point, track ball, touch pad
z May be mechanical z Scanner
or optical
z Digital camera
z Most models have a
“wheel” for scrolling z Touch screen
z Voice
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Output Devices Monitors
z Monitor z Made up of tiny
elements called
z Printer pixels
z Each row of pixels is
z Disk Drive called a scan line
» Can also be input device z Picture is displayed
by an electronic
z Modem beam lighting up
» Can also be input device certain pixels
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Monitors - Resolution Monitors - Dot Pitch
z Resolution is how sharp and clear the z Measures the distance between pixels
picture is
z Commonly seen on monitors advertised
z How many scan lines on the screen » .49 (not very good)
– 640 x 480 is low resolution » .28 (much better)
– 1600 x 1200 is high resolution
» .26 or lower (excellent)
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Monitors - Sizes Monitors - LCD
z Screen measured diagonally z Liquid Crystal Display
» May also measure actual viewing area z Similar to digital watch
z 14” or 15”
14 15 on bargain systems z Used for notebook computers
» Should be an Active Matrix Screen
z 17” has become the standard z Also used in flat screen monitors
z 19 and 21” available but are more » Much thinner than regular CRT monitor
expensive. » More expensive than regular CRT monitor
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Monitors - Video Card Monitor - Buying Hints
z Processes info to send to monitor z 17” or larger
z Amount of video memory may speed up
z .28 dot pitch or better
graphic intensive programs
» 32 megs –general purpose z 32 or more megs of memory on
» 128 or more megs – graphic intensive use video card
z AGP port can speed up graphics
z 3D accelerator card improves graphics
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Printers Printers - Laser
z Laser z Works similar to a copy machine
» Color printers available but more expensive
z Ink Jet z Fast, quite, with excellent quality
z More expensive to buy and operate
z Dot Matrix
z Some units scan, photocopy, and print
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Printers - Ink Jet Printers - Dot Matrix
z Squirts small jet of ink onto paper to z Strikes pins against ribbon to print
form characters
z Replaced dot matrix z Comes in 9 and 24 pin
z Quiet z Once very popular
z Does good job on color
z Now replaced by ink jet and laser
z Good quality and reliability
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Printers - Speed Printers - Quality of Print
z One measure is dots per inch (DPI)
z Measured in pages per minute (PPM) » 300 dpi for general purpose uses
» 600 dpi for higher quality
z Laser printers range from 20-45 ppm » 1200 dpi for photo quality
z May have different vertical and
» Color printing is slower horizontal resolution
» 600 x 300
z Other factors can affect quality
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Basic Processing Cycle How Information Is Stored
z Memory consist of switches which can
be either on or off - Off=0 On=1
Central Internal
Data z Each on/off switch is called a bit
Processing Memory
Bus z Eight bits make up a byte
Unit
z It takes one byte to store a character
» Character can be letter, space, punctuation,
etc.
» ASCII code used
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Other Memory Terms Central Processing Unit
z Byte is eight bits z Also called CPU, processor or
z Kilobyte (KB) is approx. 1,000 bytes microprocessor
z Megabyte (MB) is approx. 1million bytes z Is the “brains” of the computer
z Gigabyte (GB) is approx. 1 billion bytes z Performs all computer operations
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CPU - IBM COMPATIBLES Pentium class processors
z Many made by company called Intel z Needed to run most current software
z Intel – Celeron or Pentium IV
z Also made by AMD
z AMD
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CPU - Clock Speed CPU - Misc.
z Number of “cycles” per second z Performance also affected by speed of
computer can operate data bus
» 400-800 MHz on most current systems
z Measured in megahertz (MHz)
z Cache can increase speed
z One MHz = 1 million cycles per second
» Stores data you will likely need next in an
z One gigahertz(GHz)=1 billion cycles area that has faster access
z Current speeds 2-4 GHz » Both memory cache and disk cache used
» Should be 512 K or better
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CPU - Buying Hints Internal Memory - RAM
z Minimum of Pentium IV or AMD Athlon z RAM - Random Access Memory
» CPU can access any location as quickly as any
other
z Can not only read current info but also write
z Minimum of 2 GHz clock speed new info
z Very important in determining capabilities of
the computer system
z Computer should have at least 256 megs -
z Minimum of 512K of cache 512 preferred (can add to later)
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Internal Memory - ROM External Memory
z ROM - Read Only Memory
» Can read info Stored in ROM
» Can
C nott write
it new info
i f into
i t ROM
z Used for “internal workings” of computer
z Buyer is not very concerned with ROM
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Floppy Drives Hard Drives
z Comes in 5 1/4” and 3 1/2” z Builtinto machine
z Made up of stack of platters
» All systems
y now onlyy have 3 1/2”
z Can store much more than floppy
z HD - High density - comes on all current drives
» 40 gigabytes should be minimum
systems
z Can access info much faster than
» 3 1/2” - 1.44 megs floppy drive
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CD ROM DVD-ROM
z Same as music CDs
z Digital Video Disk
z Are read only
z Can store over 650 megs z Can store up to 17 GB
z All programs now only sold on CD
z Can store full-length movies
z Make multimedia possible
z Come in different speeds - 20x, - 50x z Can also read CD-ROM disk
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CD-RW & DVD-RW DRIVES Storage Devices - Other
z Allows you to write to disk z USB drive
z Useful for » Very popular – 64-512 MB
» Data backup
z Tape drive
» Storage of large files
» Recording music and other multimedia files
» Similar to cassette tape
z DVD-RW » Used for backup
» Allows you to write to both CD and DVD disk
z Zip drive
» Still somewhat expensive
» 100 MB to 2 GB capacity
» Everyday use and backup
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Drives - Buying Advice Expansion Slots
z 40 gigabyte hard drive z Allows you to add capabilities
z Example of cards you can add
z One 3 1/2”
1/2 high density floppy drive
» Network card
z CD-RW drive » Modem
z DVD not yet essential but useful
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Ports Networks
z Connects computer to another
device z Connects computers
z Parallel port z LAN - Local Area
» Used primarily by printers
z WAN - Wide Area
z Serial ports
» Modem, mouse, etc. z Wireless
z SCSI - chain devices z Allows sharing of
z USB –may be needed for programs, files,
» Digital Cameras
» Mp3 players
printers, etc.
» Other devices z Server is “main”
computer
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Modems - General Modems
z Allows 2 z Bits per second(bps) indicates speed
computers to » Old modems - 9,600, 14,400, 28,800, 33,600
» 56,000 (56K) has becoming standard
communicate over
phone lines z Ways of connecting to the Internet
z Can be internal or » Dial-up modem – used in most homes
» Cable modem – uses TV cable lines
external
» DSL – modified phone line
z Can also have fax » T1 line – used by schools, businesses, etc.
capabilities
Buying Hints Summary - Min 53
Buying Hints - Software 54
Hardware Requirements Bundles
z 2 GHz Pentium IV Class Processor z Many systems come with software included
z 256 megabytes of RAM z Productivity
» Microsoft Works
z 17”,, .28 dot pitch
p monitor with 32 meg
g card
» Microsoft
Mi ft Office,
Offi Lotus
L t SmartSuite,
S tS it etct
z 40 gigabyte hard drive » Quicken, Money, or other financial software
z CD-RW z Reference
z 56k modem » Microsoft Encarta or Compton’s encyclopedia
z Ink jet or laser printer z Games
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Buying Hints - Service and 55 56
Warranty Buying Hints - Web Sites
z Toll-free 24 hr 7 day support (800 #) z On-line computer stores
z 1 year warranty on parts and labor » C-Net
C Net Hardware – reviews and prices from
many vendors
z Optional extended warranty » Dell - http://www.dell.com/
» Gateway - http://www.gateway.com/
z 30 day return policy
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Programs
z Set of instructions to the computer
z Programming languages
» Machine language
» Assembly language
» Procedural languages
– Basic, Fortran, Cobol
» Object oriented languages
– Visual Basic, C++, C#, Java
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Systems Software Applications Software
z Run fundamental operations z Helps you to accomplish a certain task
» Loading and running programs
» Saving and retrieving data z Examples
» Communicating with printers
printers, modems
modems, etc
etc.
» Word processing - memos, reports, etc.
z Examples of systems software » Spreadsheets - budgets, etc.
» DOS
» Database - search, sort, select data
» Windows 3.1, 95, 98, Me, 2000, and XP
» Unix » Educational - simulations, practice
» Linux » Graphics - charts, diagrams
» Desktop publishing - pamphlets, etc.
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Software - Legal Issues Software Viruses
z Commercial software z Illegal code added to a program
» Can only make backup copies for yourself z May spread to many computers
» Can only use on one machine at a time » Copy files from one computer to another
– Site license - use on more that one machine
» Download files by modem
z Shareware » E-mail attachments
» Can use - make copies and give to anyone z Virus may be relatively harmless
» Should pay if you continue to use » Writes “You’ve been stoned” on screen
z Freeware – can copy and use indefinitely z Virus may also be very damaging
» Erases everything on hard drive
z Virus may activate on a certain date
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Virus Protection
z Be careful where you copy files from BASIC COMPUTER
z Do not open e-mail attachments unless
CONCEPTS
you are sure that it is safe
z Use virus protection program
End of Slide Show
» Detects and removes illegal code
» Should be updated often
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