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Computer Concepts

ISYS 1050A

Mrs. Karla Steere

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Computer

Literacy

Proficiency

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Purposes of Computers

Business purposes/uses

Personal purposes/uses

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Types of Computers

Personal Computers

Personal Digital Assistants

Workstations

Mainframes

Supercomputers

Servers

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Types of Computers

Personal Computers

Desktop & laptop/notebook

Personal and business use;

animation, sound recording

Personal Digital Assistants

(PDA)

Personal, on-the-go tasks;

appointment calendars

Small, very portable, connect

to PC’s to exchange info.

Handheld

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Workstations

Engineers: model airplane

fuselages

Create digital video and animation

Expensive Powerful desktop

computers

Specialized tasks

Mainframes

Banks

Airlines

Insurance companies

Universities

More powerful

Mid- to large-size capacity

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Supercomputers

Weather forecasting

Oil exploration

Aircraft design

Scientific computations

Fastest

Highest-capacity

Thousands of processors

Very expensive

ServersA computer in a

network

Provides services (access to files,

shared peripherals)

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Information Systems

Hardware

Software

Data/information

Procedures

People

Communications/Connectivity

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What Is a Computer?

A device made up of:ElectronicElectromechanicalMechanical

Referred to as “hardware”

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Software

Instructions

Programs

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Data/Information

Data Raw facts and figures

Information Processed data

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Procedures

Documentation

On-line Manuals

Common Methods

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Communications and Connectivity

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Peripheral Devices

External devices connected to the computer, but not inside the main cabinet/unit

Examples: keyboard, mouse, monitor, printer

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Hardware Categories

Input

Processing and Memory

Storage

Output

Communications

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Input Devices

Accept data

Convert data to form that can be processed

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Types of Input Devices

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Processing Hardware

Microprocessor - CPUControl Unit – interprets instructionsArithmetic/Logic Unit – processesMeasured in Megahertz or MIPS

Coprocessors – math or graphics

ROM BIOS – firmware

Machine Language

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Processors

1.5” – square chip attached to

motherboard

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Motherboard

Aka: system board

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Memory

Memory (RAM) – data & InstructionsKilobytes or MegabytesPower off – contents are gone

More memory means you can open more programs

Registers – instructions & data are loaded here just before processing

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Memory

Memory (RAM) – data & Instructions Kilobytes or Megabytes Power off – contents are gone

More memory means you can open more programsRegisters – instructions & data are loaded here just before processingMost common memory—found in printers and other devices

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Cache

High-speed memory

Keeps information about instructions used over and over again here for fast access

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Clock Speed

Timing device that controls pace.

Hertz

Megahertz (MHz)

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Memory

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Memory and Storage Capacity

Approximate values:b or Bit – 1 binary digitB or Byte – 8 bitsKB or Kilobyte – 1 thousand bytesMB or Megabyte – 1 million bytesGB or Gigabyte – 1 billion bytesTB or Terabyte – 1 trillion bytes

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Storage Hardware

3.5" Floppy Disk Drive

Iomega Zip and Jaz Drives

CD-R and CD-RW

DVD-R and DVD-RW

Hard Disk Drive

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Storage Devices

1.44 MB 100 or 250 MB CD-680 MB

Up to 100 GB1-2 GB

DVD-4 to 17 GB

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3½" Floppy Disks

High Density1.44 MB

Data is recorded in sectors

Formatting – readies disk for use

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Hard Drives

December

2001

40 GB $79

60 GB $149 -$179

80 GB $199

August 2002

80 GB $169

120 GB $149

160 GB $179

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Iomega Zip Drives

100 or 250 MB

$70 – $135 Internal or External USB

Disks $8 - $15

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Iomega Jaz Drive

1 or 2 GB

$90+ Internal or External USB

$99 (One 1GB Disk)

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Compact Discs – Optical Discs

CD-ROM (compact disk ROM)CD-R (compact disk-recordable)CD-RW (compact disk-rewritable)

DVD-ROM (digital video disc-ROM)DVD-R (digital video disk-recordable)DVD-RW (digital video disk-rewritable)

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Compact Disks

680 MB

Speeds (e.g., 40X)

CD-ROM CD-R CD-RW

Retrieve data X X X

Write (save) X X

Modify & save X

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Digital Video Disks

4.7 – 17 GB

Speeds (e.g., 16X)

Movies and Multimedia Presentations

DVD-ROM DVD-R DVD-RW

Retrieve data X X X

Write (save) X X

Modify and save X

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Compact Disk Speeds

SpeedTransfer Speed

Per Second

4x 600 K (4 x 150KB)

12x 1.8 MB

24x 3.6 MB

40x 6 MB

Transfer Speed is the speed at which data is transferred from the CD into

memory.

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Data Disk Rules

Keep away from extreme temperatures.

Keep disks and CDs in storage cases.

Keep disks away from magnetic forces.

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Read and Write

Read Copies data from storage medium to RAM.

Write Copies data from main memory to storage medium.

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Tracks and Sectors

TracksElectronic storage binsClosed concentric ringsDivided into sectors

SectorsTrack subdivisionWedge-shaped

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File Allocation Table (FAT)

Files are saved in clusters.

FAT maintains list of files and physical locations.

You should backup files regularly in case FAT damaged!

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Fragmented Disk

Files stored in noncontiguous clusters

Slow access

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Defragmented Disk

Clusters for files moved to contiguous clusters

Data access: more efficient

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Formatting

Prepares disk to be able to store data.

Makes sure sectors are reliable.

Marks bad sectors to avoid trying to save there

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Output Devices

Return processed data in form of information

View and use information

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Soft & Hard Copy

Soft Copy—temporary displayMonitor

Hard Copy—more permanent displayPrinted copy

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Types of Output Devices

Monitor

Printer

Speakers

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Monitor Types

CRT Monitors Similar to TV

technology Heavy and bulky

LCD Monitors Flat monitors Difficult to view from

angles

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Monitor Sizes

Physical Size15" small17" medium19" & 21" large

Viewable Size (Area)Actual area you see

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Monitor Clarity

Resolution (pixels per square inch)640 x 480800 x 6001280 x 1024

Dot Pitch (spacebetween pixels)

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Types of Printers

Laser

Inkjet

Dot Matrix

Requires a driver

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Laser Printers

Prints series of dots created on a drum (like a copy machine).

Transfers drum image to paper.

Prints 12-25 ppm.

Produces highest-quality printouts.

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Inkjet Printer

Sprays ink on page.

Costs less than laser printers.

Prints up to 15 ppm (depending on b&w or color, # of images, etc.)

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Dot Matrix Printers

Prints by striking mechanism against ribbon, similar to typewriter.

Produces up to 337 cps (slow).

Produces lower resolution than laser or ink-jet.

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Audio Output

Voice

Sound

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Communications

Wired (telephone lines, cable)

Wireless (microwaves, satellites, radio waves)

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Computer Basis

Digital

Analog

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Digital Basis of Computers

Binary CodeTwo-state

1 digit0 digit

Binary DigitBITBYTE

8 bits1 character, symbol, number

9:30

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Analog Basis of Life

Continuously variable values

Wave-like pattern

ModemModulate/Demodulate

makes possible transmission

of digital signals

over analog lines

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Modems

Converts digital signals to analog to transmit over phone lines and back to digital for the receiving computer.

Transmits up to 56K on telephone modem.

Transmits up to 2 Mbps on cable modem.

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Networks

LAN

T1 and T3 connections

Network Interface Card

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Port

A socket on the outside of the system unit connected to an expansion board on the inside of the system unit

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Parallel ports 15 ft limit Printers 25-pin connector

Serial (RS-232) COM 1 COM2 (communication ports)

mice Modems

9- or 25-pin connector

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SCSI port Faster parallel interface than regular parallel or

serial interface

Video adapter port Connects monitor

USB High-speed connections for printers, digital

cameras, scanners, etc.

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Expansion Slots & Boards

Expandability Increase computer’s capacity for adding more

memory and/or peripheral devices

Sockets on the motherboard into which you can plug expansion cards

PCMCIA Card Enables installation without rebooting system

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Miscellaneous

ErgonomicsWork environment to improve safety and

health.

Carpal-Tunnel SyndromeMedical condition, or repetitive-stress

injury.

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Surge Protectors

Guards against electric spikes.

Provides different levels. Check specs before buying!

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Types of Software

Operating SoftwareEnables computer system to run

Application SoftwareDesigned for end-users to perform tasks

Excel—electronic spreadsheetsPowerPoint—professional presentations

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Software Acquisition

FreewareNo CostAuthor ownership retained

Public DomainNot copyright protectedCan be altered for user’s own purposes.

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Open SourceVariation of freewareMachine-readable formatUseable but not can’t copy

SharewareFreely distributed for trial period onlyExpected to pay for extended use E.g., WinZip & Macromedia Dreamweaver

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Software Piracy Illegal copies of copyright-protected

softwareReason for expensive softwareStealing income for authors & companies

that produce the software

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Ethics and Legalities

Copyright ProtectionDigital Millennium Copyright Act 1998Designed to protect © owner who has

invested time and money creating software

UVSC Policies http://www.uvsc.edu/policies/admin/a-10.html

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Computer Viruses

Code that transfers from one computer to another

Continuous duplication of itself to Destroy files Clog storage devices and communication

networks

Protection Software Firewalls

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Security Concerns

Authentication Makes sure user requesting access is authorized

to do so

Password Guidelines Choose carefully Mix and match letters and numbers Change passwords often Remember your passwords! Keep passwords confidential.

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Biometric SecurityTechnology that uses biological features,

such as face-scanning, iris scanning, and fingerprints to verify authorization

Increasing implemented since 9-11.

EncryptionProcess converts data into indecipherable

code to protect sensitive information, such as credit card #s on Internet.

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Resources

Webopedia

TechEncyclopedia

NetLingo The Internet Dictionary

ComputerUser High Tech Dictionary

3D Dictionary

Prentice Hall “In the News”