mcgraw-hill/irwin copyright 2002 by the mcgraw-hill companies, inc. all rights reserved. 5 -1 buying...
TRANSCRIPT
McGraw-Hill/Irwin
Copyright 2002 by the McGraw-Hill Companies, Inc. All rights reserved.
5 -1
BUYING A COMPUTER
SELECTING HARDWARE
SELECTING SOFTWARE
McGraw-Hill/Irwin
Copyright 2002 by the McGraw-Hill Companies, Inc. All rights reserved.
5 -2
BUYING A COMPUTER
DETERMING YOUR NEEDS
What do you need?
Why do you need it?
What are you going to do with it?
McGraw-Hill/Irwin
Copyright 2002 by the McGraw-Hill Companies, Inc. All rights reserved.
5 -3
BUYING A COMPUTER
Set spending limit and stick to it!
Try to get the most for your money.
Determine what is most important to you.
McGraw-Hill/Irwin
Copyright 2002 by the McGraw-Hill Companies, Inc. All rights reserved.
5 -4
BUYING A COMPUTER
Determine requirements:
Present needs
Future needs
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BUYING A COMPUTER
DETERMINE SOFTWARE REQUIREMENTS
• Word processing• Educational s/w• Business• Games• WWW
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5 -6
BUYING A COMPUTER
DETERMINE THE OPERATING
SYSTEMOR
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HARDWARE COMPONENTS
• CPU• MONITOR• KEYBOARD• MOUSE• SPEAKERS• SURGE
PROTECTOR
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5 -8
BUYING A COMPUTER
DETERMINE SIZE OF COMPUTER
• DESKTOP• PORTABLE• DOCKING
STATION
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5 -9
BUYING A COMPUTER
MICROPROCESSOR
Manufacturers• INTEL• CYRIX• AMD
SPEED
450 MHz – 2 GHz
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5 -10
BUYING A COMPUTER
MEMORY
• RAM 128 - 256 MB• CACHE – 128 KB
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BUYING A COMPUTER
SECONDARY STORAGE
HARD DRIVE (10 GB)
FLOPPY DISK
CD ROM CD-RW
DVD
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Inside the Box
• System unit– Case or box where
motherboard and system units are housed
• Motherboard– Large circuit board
inside the system unit – Holds the CPU,
memory, and other electronic components
– Also called the mainboard or system board
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Motherboard
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The Basic System
• CPU & memory largely determine the power level or speed of your computer
• To run multimedia software, you will need a more powerful computer
• To get a more powerful computer, you pay a higher price
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The Central Processing Unit
• A chip that carries out instructions it receives from system & application software
• Called CPU, microprocessor, processor, or chip
• Comes in various types or speed– Speeds quoted in megahertz or gigahertz -
# of cycles per second
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Memory
• Called RAM ( random access memory)• Temporary memory that holds
– Software instructions– Information for the CPU
• Shortage of memory will slow down processing time
• The more complex the software, the more memory you’ll need
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Computer Memory
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Capacity and Type of RAM
• A kilobyte (KB or K) is about 1,000 bytes – A kilobyte is exactly 1,024 bytes
• A megabyte (MB or M or Meg) is roughly 1 million bytes
• A gigabyte (GB or Gig) is about 1 billion bytes
• A terabyte (TB) is approximately 1 trillion bytes
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Bays For Storage Units
• A place in the system unit reserved for storage
• Types– Internal
• For hard disks• Have a least one
– External• Floppy disk drives• CD-ROMs & DVDs• Zip drives
Three 5.25 "
external bays
One 3.25” drive
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Hard Drives
• Long term storage for the operating system and application software
• Operating system and application software are copied from the hard disk to memory
• Capacity measured in gigabytes
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Removable Storage
• Two varieties– Magnetic – Optical
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Removable Magnetic Storage
• Floppy Mylar disk– Housed inside a hard plastic casing– Thin, flexible plastic disk
• 3.5 inch floppy disks– also called floppies, diskettes, floppy disks
• High-capacity disks– Zip® disk
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Optical Storage
• CDs
• DVDs
• Both are optical storage and have three formats:– Read only– Write once– Rewrite
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Optical Storage
• Read-Only CD-ROM DVD-ROM
• One-Time Writable CD-R DVD-R
• Fully Read-and-Write CD-RW DVD-RW or
DVD+RW or
DVD-RAM
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Outside the Box
• Basic output devices– Monitors– Printers
• Basic input devices– Keyboard – Mouse
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Point-and-Click Devices
• Touchpad
• Mouse– Standard mouse– Trackball– Optical mouse– Wireless mouse
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Ergonomics
• Computer work can lead to physical problems
• Ergonomics – deals with reducing discomfort
• Should sit up straight at your computer
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Monitors
• CRTs
• Flat-panel displays– Gas plasma– LCD (liquid crystal display)
• Passive matrix• Active matrix
– Called TFT (thin film transistor)– Separate transistor for every pixel
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Evaluating Monitors
• Screen size– Measured from corner to opposite corner– In a CRT, picture does not fill the screen
• Resolution– Number of pixels– Pixel (picture element) – dots that make up
the image on the screen
• Dot Pitch – distance between the centers of a pair of like-colored pixels
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Printers
• Inkjet – most popular– Make images by forcing droplets through
nozzles– Top speed is 20 pages per minute
• Laser – Forms images using an electronic process– Prints between 3 and 30 pages per minute
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Printers cont.
• Multifunction printers
– Will scan, copy, fax, and print
– Cheaper than buying all individual units
– Can be inkjet or laser
– Take up less desk space than
separate devices
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Connecting Devices to the System Unit
• USB (universal serial bus) connector– allows hot-swap Plug and Play
• Firewire – faster than USB• Serial connector
– some have 9 holes– some have 25 holes
• Parallel connector – – has 25 pins– generally used to connect printers
• IrDA (infrared data association) – for wireless devices
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Types of Connectors
Parallel Connector used
with printers, CD drives, Zip
drives.
Serial connector
used with a modem or a
mouse
USB connector used with modems,
keyboards, scanners, and a variety of other
devices
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Ports
• Connectors plug into ports
• Ports correspond to connectors
– USB ports fit USB connectors
– Serial ports have 9 or 25 pins
– Parallel ports have 25 holes
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Notebook Computers
• Small, light weight, and portable
• Can run on a battery
• Monitor or screen is usually an LCD screen
• Pointing devices are usually touchpads or trackballs built into the keyboard
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Consumer Issues
• Gaming enthusiast– Joystick– Speakers– Speed for processing
• Photography enthusiasts– Digital cameras for input– Printers– Speed for processing
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COMPUTER RESOURCES
Books & Magazines• Consumer Report• Computer Buyer’s
Guide & Handbook• PC Magazine• Computer Shopper
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BUYING A COMPUTER
Procurement Method
Purchase verses Lease• Short term rental• Computer stores• Mail order• Local computer store• Build it
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5 -39
BUYING A COMPUTER
LEARN TO USE IT• READ THE
MANUAL• TAKE A COURSE• READ TRADE
BOOKS & MAGAZINES
McGraw-Hill/Irwin
Copyright 2002 by the McGraw-Hill Companies, Inc. All rights reserved.
5 -40
BUYING A COMPUTER
CARE & MAINTENANCE
OF YOUR NEW COMPUTER.
• Location• Warranties• Treatment