Transcript Computer Hardware & Processing

Computer Hardware & Processing
Outside the Box
CSC 101
1.0
September 9, 2010
Computers Are Data-Processing
Devices
• A computer’s four major functions:
– Gathers data (users input data)
– Processes data into information
– Outputs data or information
– Stores data and information
• Plus
– Computers can communicate with other
computers
Data vs. Information
• Data: Representation of a fact, figure, or idea
• Information: Organized, meaningful data
Bits and Bytes: The Language of Computers
Bit
Binary digit
0 or 1
Abbreviation “b”
Byte
8 bits
Abbreviation “B”
Each letter, number,
and character is a
string of eight 0s and
1s
Counting Bytes
Name
Abbreviation
Number of Bytes
Relative Size
Byte
B
1 byte
Can hold one character of data.
Kilobyte
KB
1,024 bytes (210 bytes)
Can hold 1,024 characters or about half of
a double-spaced typewritten page.
Megabyte
MB
1,048,576 bytes (220 bytes)
Gigabyte
GB
1,073,741,824 bytes (230 bytes)
Terabyte
TB
1,099,511,627,776 bytes (240 bytes)
Can hold approximately 768 pages of
typed text.
Approximately 786,432 pages of text; 500
sheets of paper is approximately 2 inches,
so this represents a stack of paper 262
feet high.
This represents a stack of typewritten
pages almost 51 miles high.
Petabyte
PB
1,125,899,906,842,62 bytes (250 bytes)
The stack of pages is now 52,000 miles
high, or approximately one-fourth the
distance from the Earth to the moon.
Exabyte
EB
1,152,921,504,606,846,976 bytes (260
bytes)
The stack of pages is now 52 million miles
high, or just about twice the distance
between the Earth and Venus.
Zettabyte
ZB
1,180,591,620,717,411,303,424 bytes
(270 bytes)
The stack of pages is now 52 billion miles
high, some 20 times the distance between
the Earth and Pluto.
Computer Hardware & Computer
Software
Computer Hardware
• Anything you can kick
Computer Software
• Intangible instructions that
tell the hardware what to
do.
– Systems Software
– Applications Software
Basic Computer Hardware
Components
• System Unit – everything in the box
– Motherboard, CPU, memory
• Peripheral Devices – everything outside of the
box
– Keyboard, mouse, monitor, printer
• Storage Devices – where data/information
gets stored
– Hard drive, CD/DVD, flash drive, memory cards
Input Devices
• Translates what humans understand into a
format the computer understands
• Different types of devices for different types of
data
– Keyboard
– Mouse/pointing device
– Microphone
– Scanner
– Digital camera
– Stylus
Keyboards
• Used for entering text and commands.
• The QWERTY layout is standard on most PCs.
• Enhanced keyboard features include number,
function, and navigation keys.
• Notebook keys are smaller and use a function key to
expand functionality.
So what is this??
More Specialty Keyboards
• Virtual laser keyboard
• Configurable keyboard
Point and Draw Devices
• Optical mouse
– Needs no mouse pad
– Doesn’t need cleaning
• Trackball
– Easier on wrists
– Stays stationary on desk
More Point and Draw Devices
• Wireless mouse
– Uses radio or light waves
• Touchpad
– When a mouse just
won’t do
Other Text and Command Input
Devices
• Game controllers
• Touchscreens
• Digital pens
Image Input Devices
Digital cameras, camcorders, and
cell phones
• Still images
• Video
Webcams
• Live video
Sound Input Device
• Microphones are used for:
– Podcasts
– Video-conferencing
– Internet phone calls
– Speech recognition
Output Devices
Convert what the
computer understands into
a format that humans
understand
Output can be in two
formats
Hardcopy – tangible
Printouts
Softcopy – in tangible
Video, sound,
images on
monitors
LCD Monitors
• LCD – Liquid Crystal Display
• Screens are grids made up
of millions of pixels
• Each pixel is represented by
a bit pattern comprised of
a combination of red,
green, and blue
• Liquid crystal is sandwiched
between two transparent
layers to form images
LCD Monitor Characteristics
• Resolution – total number of pixels, can be changed
• Screen size
– 21” monitor - 1680x1050 pixels
– 19” monitor - 1440x900 pixels or 1280x1024 pixels
– Wide screen vs. standard 4:3 ratio
• Viewing angle – visibility from the side
• Contrast ratio – brightest white to darkest black
• Brightness – greatest amount of light when displaying
pure white
• Response time – time it takes for a pixel to change
color
Printer Categories
• Impact printers
– Dot-matrix
• Nonimpact printers
– Inkjet
– Laser
• Specialty printers
– All-in-one
– Plotters
– Thermal
Nonimpact Printers
Inkjet
• Less expensive device
• Print high-quality color
images cost effectively
Laser
• More expensive device
• Faster printing speed
• Color lasers are becoming
less expensive
Printer Characteristics
• Speed (ppm)
• Resolution (dpi)
• Color output
• Memory
• Use and cost
• Cost of consumables
Storage Devices
• Non-volatile
– Almost permanent
• Types of computer storage devices
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Internal hard drive
USB flash drive
Memory cards
Optical drive
External hard drive
Online storage
• Secondary storage
Hard Drive
• May be internal or
external
– Internal is faster
• Storage capacity is up
to 2 terabytes (TB)
• Access time is
measured in
milliseconds
• Data transfer rate is
measured in megabits
or megabytes per
second
How a Hard Drive Works
Composed of coated
platters stacked
on a spindle
Data saved to the disk:
Pattern of magnetized
spots
– Spots = 1
– Spaces = 0
Spots are translated
into data
Optical Storage
• Optical media: Store data as tiny pits burned into
a disc by a laser
– Pre-recorded
• CD-ROM, DVD-ROM, BD-ROM
– Recordable
• CD-R, DVD-R, BD-R
– Rewritable
• CD-RW, DVD-RW, BD-RE
• Uses a burner to write to optical media
• Uses two lasers to read optical media
Flash Memory
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Flash / thumb drive
Memory cards
Electron grid / gates
High storage capacity
Use very little power
Must unmount before removing from
computer
• Can cause security concerns
Online Storage
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Data stored on the Internet
Inexpensive
Data backup
Can access data anywhere
Can be password protected
All Storage Media Will Fail
Back up your data!