© K. Mulbery & C. Krebs, CITE Dept., UVSC1 Computer Concepts ISYS 105A

© K. Mulbery & C. Krebs, CITE Dept., UVSC 1

Computer Concepts

ISYS 105A


Computer Literacy vs. Computer Proficiency

Literacy• Knowledge and understanding of basic

computer terminology

Proficiency• Ability to use computer applications to

complete tasks efficiently, accurately, and effectively.


Computers & Purposes Computer (p. 4 Concepts book) Purposes (pp. 4-9 Concepts book)

• Personal Uses• Internet Surfing• Personal & School Correspondence• E-Mail Communication

• Business Uses• Reports• E-Mail• Internet


Types of Computers

Personal Computers Personal Digital Assistants Workstations Mainframes Supercomputers


Types of Computers (pp. 13-15 Concepts Book)

Personal Computers

StationaryDesktop

PortableLaptop/notebookTablet PC

Personal and business use;

correspondence;Laptop—portable

Personal Digital Assistants (PDA)

Personal, on-the- go tasksAppointmentsCalendars

Small, very portable, connect to PCs to

exchange info.


Workstations

ExpensivePowerful systemHigh-quality graphics

Engineers: model airplane fuselages

Create digital video and animation

Mainframes

Less powerful than Supercomps Mid- to large- size capacity

Banks

AirlinesInsurance companies

Universities


Supercomputers

FastestHighest- capacityThousands of processorsVery expensive

Weather forecasting

Oil exploration

Nuclear energy research


Information Processing Cycle

Input Processing Storage Retrieval Output


Hardware

Physical parts of the computer• System Unit

• Computer itself and its components

• Peripherals• Separate devices connected to the system

• Examples: keyboard, monitor, mouse


Software

Instructions Programs


Hardware Categories

Input Processing and Memory Storage Output Communications


Input Devices

Accept data Convert data to form that can be

processed


Types of Input Devices(pp. 20-21 Concepts Book)


Processing Hardware (pp. 16-17 Concepts Book)

Motherboard(System Board)• Large circuit board• Contains electronic chips• Contains electronic

pathways, known as buses


Processing Hardware (pp. 16-17 Concepts Book)

Central Processing Unit (CPU)• 1.5-inch chip w/ electric circuits• Computer brains:

control and manipulate data• Measured in gigahertz (GHz)


Temporary Memory Random Access Memory

(RAM)• Chips providing temporary

working storage for data

• Waiting room for data & instructions to be processed

• Power off – contents are gone

Capacity• More memory means you can

open more programs

• Typical: 512 MB


Clock (Processing) Speed

Timing device that controls rate that system executes instructions

1 Hertz = 1 cycle per second (cps) Megahertz (MHz) 1 Gigahertz (GHz) = 1 billion cps


Memory and Storage Capacity

Approximate values:• b or Bit – 1 binary digit• B or Byte – 8 bits• KB or Kilobyte – 1 thousand bytes• MB or Megabyte – 1 million bytes• GB or Gigabyte – 1 billion bytes• TB or Terabyte – 1 trillion bytes


Storage Hardware(pp. 17-18 Concepts Book)

3.5" Floppy Disk Drive Iomega Zip Drive USB Jump Drive

(a.k.a. Memory Stick or Flash Drive) CD-R and CD-RW DVD-R and DVD-RW Hard Disk Drive


Storage Devices

1.44 MB

100, 250, 750 MB

CD-650-700 MB

160 GB Plus1-2 GB

DVD-4 to 17 GB

USB Jump 256 MB,512 MB, 1.5 GB


3½" Floppy Disks

1.44 MB High Density Data is recorded in sectors Pros: Portable & good for small files Cons: Limited life, temperature sensitive,

not durable, limited space


Iomega Zip Drives

100, 250, or 750 MB Pros: removable storage, higher

capacity, very durable Cons: device not on all machines,

larger-capacity disks can’t be used in lower-capacity drives

Cost: $14.99 each; $89.99 eight-pack


Read and Write

Read Copies data from storage medium to RAM.

Write Copies data from main memory to storage medium.


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)


Compact Disks

CD-R (650-700 MB) CD-RW (680 MB) Pros: Equivalent to about six 100 MB

Zip disks, portable, CD-RW are re-writeable

Cons: CD-R only burn once; breaks easier than Zip disks

Speeds (e.g., 40X)


CDs

CD-ROM

CD-R CD-RW

Retrieve data X X X

Write (save) X X

Modify & save

X


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.

Example:32 X 10 X 4032 write10 rewrite40 read


Universal Serial Bus (USB) Jump/Flash Drive

(p. 23 Concepts Book) Variable Memory

• 256 MB (about $25)*• 512 MB (about $40-50)*• 1 GB (about $76)*

Plugs into USB port Pros: Extensive storage,

portable, fast Cons: More expensive*Look for rebates in weekly advertisements.


Digital Video Disks (DVDs) 4.7 – 17 GB Pros: Movies & Multimedia Cons: DVD-R, DVD+R only one

write; watch compatibility + and -

DVD-ROM DVD R DVD RW

Retrieve data X X X

Write (save) X X

Modify and save X


Hard Drives

Device for long-term memory Located in system unit (C drive) Cost: About $130 for 250 GB Firewire (portable hard drives)


Data Disk Rules

Keep away from extreme temperatures.

Keep disks and CDs in storage cases. Keep disks away from magnetic

forces.


Tracks and Sectors

Tracks• Electronic storage bins• Closed concentric rings• Divided into sectors

Sectors• Track subdivision• Wedge-shaped



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!


Fragmented Disk(p. 35 Concepts Book)

Files stored in noncontiguous clusters Slow access


Defragmented Disk

Optimizes drive Clusters for files moved

to contiguous clusters Data access: more efficient


Output Devices (pp. 21-22 Concepts Book)

Return processed data in form of information

View and use information


Types of Output Devices

Monitor Printer Speakers


Soft & Hard Copy

Soft Copy—temporary display• Monitor

Hard Copy—more permanent display• Printed copy


Monitor Types

CRT Monitors• Similar to TV technology

• Heavy and bulky

LCD Monitors• Flat monitors

• Difficult to view from angles


Monitor Sizes

Physical Size• 15" small• 17" medium• 19" & 21" large

Viewable Size (Area)• Actual area you see


Monitor Clarity

Resolution (pixels per square inch)• 640 x 480• 800 x 600• 1280 x 1024

Dot Pitch (spacebetween pixels)

Resolution


Types of Printers

Laser

Inkjet

Dot Matrix


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


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.)


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


Audio Output

Voice Sound


Communications

Wired (telephone lines, cable)

Wireless (microwaves, satellites, radio waves) see p. 24


Data Communication

Digital

Analog


Analog Basis of Life

Continuously variable values(e.g., sound waves are not static)

Wave-like pattern


Digital Basis of Computers

Binary Code• Two-state

• 1 digit• 0 digit

Binary Digit• BIT• BYTE

• 8 bits• 1 character, symbol, number


ModemsModulator-Demodulator (p. 19 Concepts Book)

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 high-speed

cable modem.Look up DLS modem speeds on the Internet.


Network (p. 20 Concepts Book)

Connects a group of computers Shares resources

• Printers• Files


Network Types

Local Area Network (LAN)• Short distances (1 floor or 1 building)

Wireless Network• No physical connection among computers

• Gaining popularity for household use

T1 and T3 connections• Leased phone lines

• High-speed

Network Interface Card• Card enabling system

connection to a network


Ports

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


Parallel Ports• 15 ft limit

• Printers

• 25-pin connector

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

• Mice

• Modems

• 9- or 25-pin connector


Video adapter port

• Connects monitor

USB

• High-speed connections for printers, digital cameras, scanners, etc.


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


Miscellaneous Ergonomics

• Work environment to improve safety and health.

Carpal-Tunnel Syndrome• Medical condition, or repetitive-stress injury.

OSU Ergonomic Information


Surge Protectors

Guards against electric spikes. Provides different levels.

• Check specs before buying!


Types of Software (pp. 42-47 Concepts Book)

Operating Software• Enables computer system to run

Application Software• Designed for end-users to perform tasks


Software Acquisition

Freeware• No Cost• Author ownership retained

Public Domain• Not copyright protected• Can be altered for user’s own purposes.


Open Source• Variation of freeware

• Machine-readable format

• Useable but not can’t copy

Shareware• Freely distributed for trial period only

• Expected to pay for extended use

• E.g., WinZip & Macromedia Dreamweaver

Site License• Agreement that allows an organization to install

software on X number of machines.


Software Piracy• Illegal copies of copyright-protected

software• Reason for expensive software• Stealing income for authors & companies

that produce the software

Software Piracy


Utility Software (pp. 48-52 Concepts Book)

Anti-Virus Software• Minimize or prevent damage caused by

computer viruses Backup

• Create copy of important files in case of accidental deletion, virus, damage, etc.

File Compression• Create file that takes up less space than usual;

good for sending as e-mail attachment


Ethics and Legalities

Copyright Protection• Digital Millennium Copyright Act 1998• Designed to protect © owner who has

invested time and money creating software

UVSC Policies


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


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.


Biometric Security• Technology that uses biological features, such

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

• Increasing implemented since 9-11. Encryption

• Process converts data into indecipherable code to protect sensitive information, such as credit card #s on Internet.


Resources

Webopedia TechEncyclopedia NetLingo The Internet Dictionary ComputerUser High Tech Dictionary 3D Dictionary Prentice Hall “In the News”

Documents

© K. Mulbery & C. Krebs, CITE Dept., UVSC1 Computer Concepts ISYS 105A