Concepts 7 Unit B Ppt

Computer Concepts - Illustrated Computer Concepts - Illustrated Introductory, Seventh EditionIntroductory, Seventh Edition

UNIT B:

Computer Hardware

ObjectivesObjectives

Examine input devices

Review display devices

Compare printers

Introduce storage technology

Compare storage technologies

Computer Concepts – Illustrated Introductory, Seventh Edition

ObjectivesObjectives

Explore hard drive technology

Examine CDs and DVDs

Review solid-state storage

Expand your computer

Talking Points: Why recycle computers?


Examining Input DevicesExamining Input Devices

Input devices - input information for computer to process

Typical input devices Keyboard and pointing device (mouse)



Keyboards Most have a similar structure Can be found on PCs, handheld devices

Keyboard includes keys or buttons with letters, numbers, and special words and characters



Desktop and notebook computer keyboards include Navigation keypad Home, End, arrow keys Used to move screen-based insertion

point (cursor)



Mouse Pointing device which manipulates an

on-screen pointer and other on-screen controls



Mouse options - Mechanical mouse

• Position based on movement of ball that rolls on pad

Optical mouse• Uses LED light and computer chip

Laser mouse• Uses laser as light source to track

movement



Mouse dots per inch (dpi) Higher dpi more sensitive and accurate

Mouse transmits signals one of two ways Wired or Wireless

Most prefer optical or laser Durability Less maintenance Can be used on variety of surfaces



Other pointing devices Pointing stick or TrackPoint Touchpad or trackpad Trackball Joystick



Other input devices Touch screen technology Scanner Microphone


Reviewing Display DevicesReviewing Display Devices

Computer display system Main output device

Two key components Graphics card Display device such as monitor or screen

Use one of three technologies CRT, LCD, plasma



CRT Monitor(cathode ray tube) used to be standard Big and bulky Not typically sold with new computers

today



LCD (liquid crystal display) Produces image by manipulating light

within layer of crystal cells

Advantages include Display clarity Low radiation emission Portability and compactness



Plasma Creates on-screen image by illuminating

miniature colored fluorescent lights arrayed in panel-like screen

More expensive than LCD Used more for large screen venues



Graphics cards Contain graphics processing units (GPU)

• Circuitry generates signals for displaying image on screen

Amount of available video memory• Key to how fast screen updates when information is

displayed

Typically built into motherboard Sometimes available as small circuit board that

plugs into motherboard



Graphics card - key to how images display on monitor Resolution

• Maximum number of horizontal and vertical pixels displayed on screen

Pixel (picture element)• single point or smallest unit in image



Comparing Screen Resolution



Screen size Measurement in inches from one corner

of screen diagonally to opposite corner Typical monitor sizes

• 13” to 21”• Larger screens exist

Viewing angle width How far to side you can clearly see

screen image



Dot pitch (dp) Measure of image clarity Smaller dp means crisper image

Dot pitch - distance in millimeters between like-colored pixels Ranges from .26 mm to .23 mm Not customizable



Color depth or bit depth Number of colors monitor and graphics card

can display Most PCs can display millions of colors

Monitors can be used to watch television if proper circuitry is installed NTSC or HDTV circuitry

• Allows PC to accept signals from antenna or cable


Comparing PrintersComparing Printers

Printers Produce hard copy of computer-generated text

or graphical images• Paper, labels, transparencies

Differ in resolution and speed Most printers use ink-jet or laser

technologies

Specialized applications Impact, solid ink, thermal transfer, dye

sublimationComputer Concepts – Illustrated Introductory, Seventh Edition


Ink-jet printers Sprays ink onto paper to form characters

and graphics Two ink cartridges: Black and color Small, lightweight, inexpensive Cartridges can be expensive and add to

printing costs



Laser printer Produces dots of light on light sensitive drum to

produce characters and graphics Good high-volume, good quality printing More expensive than ink-jet Color laser printers more expensive than black-

and-white Toner cartridges are expensive, produce more

pages than ink-jet cartridges



Photo printers Use thermal dye Slower output speeds than other

printers Produce professional-quality images on

specialized papers Cost of replacement cartridges should

be considered



Printer resolution Density of grid of dots that create image Measured in dpi (dots per inch)

• At reading distance, 900 dpi looks solid• Good-quality printers are rated 2400 to 4800

dpi• Magazine quality printouts are about 900 dpi• Expensive coffee-table books are

comparable to 2400 dpi or higher



Pages per minute (ppm)• Measurement of printer speed• Color usually takes longer to print than

black-and-white• Text prints faster than heavy graphics• Most printers for personal or small business

print 15 to 30 ppm

Memory capacity• More memory needed to print color and

graphics• Laser printers: Between 64 MB and 120 MB



Duplex printer Can print both sides of paper

Duty cycle Proportion of time during which device is

operated Usually measured in pages per month Higher duty cycle means shorter useful

life



Computer connected to network can share printer with other computers on network

Network-enabled printer Connects directly to network, not single

computer Network connection can be wired or

wireless


Introducing Storage TechnologyIntroducing Storage Technology

Storage technology Data storage systems that allow

electronic devices to store and retrieve data

Data storage consists of storage medium and storage device



Storage medium Hard drive, tape, memory card, CD,

DVD or other technology that holds data



Storage device Equipment that stores and retrieves data from

storage medium Hard drives, card readers, tape drives, CD and DVD

drives, flash drives, solid-state drives, Zip drives



Hard drive Computers come with internal hard drive Can’t be moved from one computer to another Provide fast data access

Some storage devices are more dependable than others CDs, DVDs

Flash drives and external hard drives Can be moved from computer to computer



RAM (random access memory) Temporary holding area for your work

and programs needed to produce your work

RAM - emptied when computer shuts off Data easily lost

• Store data on storage medium, not as likely to lose work



Drive bays Storage “parking spaces”

• In system unit case• Used to connect storage devices to computer

Internal or external

When buying computer, find out: How many drive bays it has What storage devices can be connected



Drive bays


Comparing Storage TechnologiesComparing Storage Technologies

Random vs. sequential access Random (direct) access

• Ability to jump directly to requested data• Hard drive, solid-state drive, CD and DVD

drives

Sequential access• Must read through data from beginning to

end• Tape drive• Slower



Access time Average time it takes computer to locate

and read data Measured in milliseconds

Data transfer rate Amount of data that can be moved from

storage medium to computer per second



Storage capacity Maximum amount of data that can be

stored on storage medium• Measured in kilobytes (KB), megabytes (MB),

gigabytes (GB), or terabytes (TB)

Graphics need more storage capacity than text



Magnetic storage Magnetizes microscopic particles on disk or

tape surface Particle patterns are interpreted as 0s and 1s Provides flexibility for editing data and reusing

storage medium



Magnetic media No very durable Eventually loses magnetic field Damaged by magnetic fields, dust, mold,

smoke, heat, mechanical problems



Optical storage Stores data as light and dark spots on surface of

disk Light patterns are interpreted as 1s and 0s Advantages:

• Portable• Quite versatile• Less susceptible

to environmental damage



Solid-state storage Stores data in nonvolatile, erasable, low-

power chip Drive has no moving parts Very durable, portable, versatile Capacity does not currently match that of

hard drives



Why Versatility? Important working with other people and

other computers Store data and share with others using

same storage medium

Why Durability? Determines ability of device or media to last

so data remains accessible Important for traveling and carrying files


Exploring Hard Drive TechnologyExploring Hard Drive Technology

Hard drives preferred type of main storageThree main reasons

• Storage capacity• Fast access• Economical

– 40 MG of storage costs about a penny



Parts of hard drive One or more platters on spindle with

associated read-write heads



Hard drives found in wide variety of digital devices

Physical size of hard drive varies depending on size of device



Factors that determine how fast data can be made available Access time (measures in milliseconds) Rotation speed (measured in revolutions

per minute)

Hard drive platters with data are divided into tracks and sectors Cylinder

• Vertical stack of tracks



Controller Circuit board that positions disk, locates

data, and interfaces with components on system board


Hard drive showing

Controller card


Adding second hard drive increases storage, provides backup Data available on only one drive at a time

Hard drives Not as durable as many other storage

technologies Head crash can be caused by particles as small

as piece of dust Handle and transport with care Always have backup copies of hard drive


Examining CDs and DVDsExamining CDs and DVDs

CDs and DVDs can be used to store data CD (compact disc) DVD (digital video disc or digital versatile

disc)

Three optical digital technologies Read-only (ROM) Recordable Rewritable



CD-ROM Read-only technology

CD-R Recordable technology

CD-RW Rewritable technology



DVD-R and DVD+R Recordable DVD formats

DVD-RW and DVD+RW Rewritable formats

Why so many? One standard has not emerged as

industry leader



Computer CD-ROM or DVD-ROM Discs cannot have data added, erased,

or changed

To record data one or more times Need recordable media (one time use) Rewritable (multiple session use) discs



Good idea to have CD or DVD drive Create music CDs or DVDs CD drives can’t read DVDs Most DVDs can read DVDs or CDs

Several types of CD and DVD drives Can be used for different purposes




CD or DVD Drive Capabilities


Rewritable CD and DVD drives Not acceptable replacement for hard

drive Saving, accessing, modifying data is

much slower Capacity is inadequate when compared

to hard drives



CD and DVD drives use laser technology to read data



Make your own CDs Need proper hardware, media

CD-R or DVD-R Must put all data on disc in one session

Rewritable technology Can record in multiple sessions



Handling CDs and DVDs


Reviewing Solid-State StorageReviewing Solid-State Storage

Solid-state storage Portable and durable Provides fast data access Uses very little power Used in consumer devices

• Digital cameras, MP3 players, notebooks, PDAs, cell phones



Solid-state storage suitable for many needs Can hold hundreds of photos Store MP3 files Portable computing

Data can be erased so card can be reused



How does it work? Nonvolatile, erasable, low-power chip

stores data Circuitry arranged in grid

• Each cell holding transistors that act as gates• Open gates represent 1, closed represents 0

Chip retains data without external power



Several types of solid-state memory cards CompactFlash cards (CF) MultiMedia cards (MMC) SecureDigital cards (SD) SmartMedia cards



Card reader Transfers data to and from computer Can stand alone, or be part of system

unit



USB flash drive Portable storage device with built-in

connector that plugs into USB port Small and durable Can be carried on key ring

U3 drive or U3 smart drive Special USB flash drive

preconfigured to play automatically when connected to computer


Expanding Your ComputerExpanding Your Computer

Expanding Increase / improve capabilities of

computer Add peripherals

• Scanners, mouse, cameras, graphics tablets, etc.

Add or upgrade sound cards, video cards, etc.



Most peripherals can be added using external USB port



Expansion cards can be added / upgraded to enhance functionality Graphics card Modem card Sound card Network card

Also called expansion boards, controller cards, or adapters



An expansion card Small circuit board that provides

computer ability to control input, storage, or output devices

Data bus Circuits over which data travels from one

component to another



Expansion bus Segment of data bus between RAM and

peripheral devices Allows data to travel through expansion slots,

cards, ports, and cables



Expansion slot Long, narrow socket on motherboard into which

expansion card is plugged

PCMCIA slot External expansion slot for PC



Expansion ports Connectors that

pass data in and out of computer or peripheral device



Device driver Software that sets up communication

between computer and device or card Each device or card needs one Directions supplied with device or card

includes instructions for installing device driver


Talking Points:Talking Points:Why recycle computers?Why recycle computers?

500 million computers were obsolete by 2007

About 1 billion floppy discs, CDs, and DVDs end up in landfills every year

Computer parts contain toxins like lead, phosphorous, and mercury Monitors can contain up to six pounds of

leadComputer Concepts – Illustrated Introductory, Seventh Edition

Talking Points:Talking Points:Why recycle computers?Why recycle computers?

Instead of throwing away Sell it Donate it to school, church, or

community program Have it hauled away by professional

recycling firm Send it back to manufacturer


Date post:	11-May-2015
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Concepts 7 Unit B Ppt

Business