Transcript Essential Introduction to Computers

Essential Introduction
to Computers
What do Computers do?
Computers can perform
4 general operations:
»Input
»Process
»Output
»Store
What is a Computer?
• An electronic device that
– accepts data (input)
– manipulates it according
to instructions (processing)
– Produces information (output)
– Stores results for future use (storage)
Computer Example
Pentium E5300 2.6GHz
4 GB DDR2 SDRAM
Coller Master Centurion
Case
Gigabyte GA-G41M
Motherboard
GeForce EVGA 9500 GT
Video Card
23" Acer Monitor
Corsair 400W Power supply
Western Digital 750 GB
Hard Drive
Logitech Keyboard and
mouse
Sony Optiarc 24X DVD
Drive
Data & Information
• Data – refers to the raw facts, including
numbers, words, images, video, and sounds,
given to a computer during the input
operation.
• Information – data that is organized, has
meaning, and is useful.
How does a computer know
what to do?
• A “Computer Program” tells the
computer what to do!
• “Binary Code” is a list of instructions
the computer carries out one byte at
a time. It is made up of 0’s and 1’s.
• A Computer Program is also called
“Software”
What are the Components
of a Computer
Input Devices
(data is entered
into memory)
CPU (processes data
stored in memory)
Output Devices
(produce results
of processing)
Storage Devices
(store data for
future use)
Motherboard
• is a Printed Circuit board(PCB) found
in many modern computers which
holds many of the crucial components
of the system, such as the (CPU) and
Memory, and provides connectors for
other peripherals.
Input Devices
• The Keyboard
– Most common input device
– Data is entered by typing
• The Mouse
– Is a pointing device
The Keyboard
• Most keyboards today are “Enhanced Keyboards”
and include:
–
–
–
–
–
Letters for alphabet & characters (yellow)
12 Function Keys (teal-across top)
Arrow keys (pink)
Additional keys (green)
Numeric Pad (purple-far right)
The CPU
• CPU stands for Central Processing Unit
• Contains electronic circuits that cause processing
to occur
• Is made up of:
– Control Unit (interprets instructions)
– ALU-Arithmetic Logic Unit (performs
logical and arithmetic processes)
• Fits on a chip called a “Microprocessor”
Microprocessor
• Fits in the palm of your hand
• Contains 7.5 million+ transistors
• Capable of performing some operations 10 times
in 1/10 of a second!!
• There are different kinds of microprocessors
• The microprocessor deciphers the 0’s and 1’s by
registering Positive and negative charges.
Microprocessors
“Pentium Processor”
Designed for higherperformance PCs
(Pentium II, III, IV,
with MMX)
“Celeron Processor”
intended for basic
PCs that cost less
than $1,000.
“Xeon Processor”
is geared toward
servers and
workstations
Microprocessor speed
• Microprocessors are measured in the
amount of bytes processed per
second.
• Megahertz is the measure for
millions of bytes per second
• Gigahertz is the measure for billions
of bytes per second
• Terahertz is the measure for
trillions of bytes per second.
Memory
• Also called RAM or Random Access Memory
• Electronic components that store data
• Memory is measured in:
–
–
–
–
Kilobytes (K or KB) – 1 thousand memory locations
Megabytes (M or MB) – 1 million
Gigabytes (G or GB) - 1 billion
Terabytes (TB or Tera) – 1 Trillion
Output Devices
• Make the information resulting from
processing available for use
• Many forms include
– Paper copies printed on a printer
– images displayed on monitor
Printers
• Printers are either “IMPACT” printers or
“NON-IMPACT” printers
– Impact Printers strike an
inked ribbon against paper,
louder, less-common today
Non-Impact Printers do not strike paper
and make characters in some other way,
quieter, high-quality text & graphics, more
common today
Non-Impact Printers
• Include Ink-Jet Printers & Laser Printers
– Ink-Jet Printers--spray drops on ink on paper
to create text & graphics
– Laser Printers—works like a copy machine
using a beam of light, a photoconductor drum
and toner
• Printer prices are relative to how good the quality
of printing is and how many pages per minute they
print
Computer Screens
• Are output devices too
• They let you see what you are doing
with the computer!
• Different kinds of screens exist
Computer Screens
• Most full-size computers use a televisionlike display called a screen, monitor, or
CRT (Cathode Ray Tube)
• Laptop computers, flat-screen displays,
and handheld computers use a flat panel
LCD (Liquid Crystal Display), a technology
similar to a digital watch
• All screens are made up of picture elements
called PIXELS, which are illuminated
(or lighted) to form characters & graphics
Performance
measurements
• Luminance - measured in candelas per
square meter
• Aspect Ratio - ratio of the horizontal
length to the vertical length.
Monitors usually have the aspect
ratio 4:3, 5:4, 16:10 or 16:9.
Performance
Measurements cont.
• Display Resolution - is the number of
distinct pixels in each dimension that
can be displayed. Maximum resolution
is limited by dot pitch
• Dot Pitch - is the distance between
sub-pixels of the same color in
millimeters. In general, the smaller
the dot pitch, the sharper the
picture will appear.
Performance
Measurements cont.
• Contrast Ratio - the ratio of the
luminosity of the brightest color
(white) to that of the darkest color
(black) that the monitor is capable of
producing.
Identify these Screens!
Which is which?
A) CRT Monitor
B) Laptop
C) Flat-Panel Display
D) Hand-held device
Look!
A Laptop computer with a LCD Screen
Common computer monitor
using CRT technology
A Hand-held
device using
LCD
technology
A Flat-Panel Monitor
using LCD technology
—very popular today!
Auxiliary Storage
• A fancy way to say SAVE IT!!!
• Also called “secondary storage devices”
• Are used to store data when it is not being
used in memory
• Many kinds floppy disks, hard disks,
CD-ROMs, DVD-ROMs
Hard Disks
• Consists of one or more rigid metal
platters coated with a metal oxide
material that allows data to be recorded
magnetically on the surface of the
platters.
• Most hard disks are
NOT removable
• Is formatted into
tracks & sectors
Tracks & Sectors
• A TRACK is a narrow recording band that
forms a full circle on the surface of the
disk.
• Then, the disk is divided into pie-shaped
sections, which breaks the tracks into
small arcs called SECTORS.
SECTOR
TRACKS
Compact Discs
• CD…stands for Compact Disc
• Also known as Optical Discs
• Come in many formats:
–
–
–
–
CD-ROM
CD-R
CD-RW
DVD-ROM
CD-ROM
• Stands for…
Compact Disc-Read Only Memory
• Used to store large amounts of information—over
700 MB
• Can store “Multimedia” which includes text,
graphics, animation, video, and audio
• Music cds are CD-ROMs too!
• Must have a CD-ROM drive on your computer to
use one
(notice disc spelled with a “C”)
CD-R
• CD-R stands for…
Compact Disc-Recordable
• It holds text, graphics and audio
• Is “multisession” which means you can
write (save) on one part of disc at one time
and another part at a later time.
• Can write on each part of disc only one
time
• Can not erase the disc
CD-RW
• CD-RW stands for
Compact Disc Rewritable
• Is erasable!! You can write on it many
times!
• Is most like a floppy disk – can save,
resave, or erase as many times as you
want to.
DVD-ROM
• Stands for…
Digital Video Disc-ROM
• Very high capacity disc capable of storing 4.7 GB
to over 17 GB
• Quality is better than CD-ROM
• Movies on DVD are DVD-ROM discs!
• Must have a DVD-ROM drive on your computer to
use one—a CD-ROM drive will NOT play a DVD!
• But… a DVD-ROM drive will play a CD-ROM!!
Versatile Multilayer Disc
• is a high-capacity red laser optical
disc technology
• Has an initial capacity of up to 30GB
per side
Blue-Ray
• The name Blu-ray Disc refers to the
blue laser - Allows information to be
stored at a greater density than the
longer-wavelength red laser used for
DVDs.
• Blu-ray Disc uses a 405 nm "blue"
laser diode for high definition display
Computer Software
• Software are instructions that tell
the computer what to do!
• Two kinds:
• System Software
• Application Software
• All software is broken down into 0’s
and 1’s called the binary code.
System Software
• Programs that control the operations of computer
equipment
• An important part of system software is a set of
programs called the OS or OPERATING SYSTEM
• The OS tells the computer how to perform the
functions of loading, storing, & executing an
application program and how to transfer data
• When a computer is turned on, the OS is loaded into
memory—this is called BOOTING!
Communicating with the OS
• Today, most computers use an OS that has
an GUI or Graphical User Interface
• GUI provides pictures-called ICONS for
the user to click instead of making the
user type text-based commands
(an old OS called DOS (Disk Operating System) made users
type commands—was more difficult to use!)
• An Icon can represent an application program
such as Microsoft Word or Internet Explorer OR
a file where data is stored
– Our OS is “Windows XP”
Application Software
• Consists of programs that tell a
computer how to produce information
• All application software has a
specific purpose
• This lets you type papers, surf the
web, burn music cds, play games,
make presentations, and much more!
Types of Application Software
“Word Processing”
• Used to create, edit, format & print
documents
• Most common application software used!!
• Before computers, people used
typewriters to do this
• We will use
Microsoft Word 2007
A sample of a Word
document—looks like
a newsletter!
Types of Application Software
“Spreadsheet”
• Electronic Spreadsheet software allows
the user to add, subtract, and perform
calculations on rows & columns of numbers.
• Can automatically update calculations when
changes are made!
• Can convert numbers into graphs & charts
• We will use
Microsoft Excel 2007
Text & Numbers
A chart created
from the numbers
above it
Types of Application Software
“Database”
• Allows the user to enter, retrieve, and
update data in an organized and efficient
manner
• Allows the user to search through and
sort (or arrange) data in different ways
and create reports
• We will use
Microsoft Access 2007
(Will be the most difficult
type of software we learn
in this class)
What an Access software screen looks like
Types of Application Software
“Presentation Graphics”
• Allows the user to create a slide-show
presentation!
• You are looking at one now!!!
• A slide-show can be presented to a group of
people by using a digital video projector to
cast the images up on a large screen
• We will use
Microsoft PowerPoint 2007
Is what the
PowerPoint
screen
looks like
A Network
• Computers by themselves are great, but when you
connect them together they are a lot more
powerful and fun to use!
• A NETWORK is a collection of computers and
devices connected together with cables,
telephone lines or other high speed cables or
wireless devices.
• Computers are networked together so users can
share resources-like hardware, software, and
data
• A room full of computers can be “networked” to
share one printer
Types of Networks
• LAN or Local Area Network
– Connects computers in a smaller geographical
area such as school campus, office, group of
buildings
– Our school campus has a LAN
• WAN or Wide Area Network
– Connects computers over a large geographical
area, even across the country!
– For example…all the Best Buy stores computers
are connected together using a WAN.
A Home Network
• You can even setup a network (LAN)
in your house to connect different
computers and printers and more!
• These home networks can even be
wire-less, which means you don’t need
a cable between devices-but you would
need a special card in each device to help
the devices communicate.
• Home networks have other bonuses too-they
can provide extra security for your
computers.
The INTERNET
• The world’s largest network is the Internet
• It is a world-wide collection of networks
that links together millions of computers by
using modems, telephone lines & coaxial
cables
• Over 150 million users around the world use
the Internet
World Wide Web
• One of the more popular segments of the Internet
is the WWW—World Wide Web.
• Or just called the “Web”
• Contains billions of documents called “web pages”
• Web pages contain text, graphics, sounds/video +
• Web Pages have built-in links called “Hyperlinks”
which, when clicked, take the user to other web
pages
• Web Pages are stored on computers throughout
the world!
Why Use the Internet?
• Send messages to other users (e-mail)
• Access information such as news, maps,
airline schedules, stock market data
• Shop for goods & services
• Communicate with people around the world
(chat rooms, message boards)
• Accessing entertainment—online games,
magazines, vacation planning, live video
streams
What you need to
get on the Internet
• Most users connect to the Internet
using an ISP or Online Service
– ISP stands for Internet Service Provider—
provides monthly access to the Internet for
a $fee$
– Online Service-is like an ISP
but also offers more services
for users.
AOL (America OnLine)
is an online service.
You also need a BROWSER
• Your computer must have an application
program called a “Browser” to access the
Internet
• A “Browser” finds and displays a web page
• All versions of Windows Operating
systems (98, 2000, NT, XP) come with the
browser Internet Explorer
The Internet Explorer
browser displaying the
Yahoo web page
Web Page vs. Web Site
• A Web Page—is one individual page
that displays information
• A Web Site—is a group of web pages
A web site can made up of many individual
web pages or just one web page.
Finding a Web Page
• A web page has a unique address—called a
URL or Uniform Resource Locator.
• The computer retrieves a web page by
using its URL, which tells it where the
document is located.
• When you click a “Link” (short for
hyperlink) on a web page, the link takes
you to another URL!
What’s in a URL?
• A URL consists of a:
– Protocol
– Domain name
– Path to specific web page or location in
a web page
URLs…
• HTTP stands for HyperText Transfer Protocol and is
the communication standard for transferring web
sites on the Web.
• The Domain Name
identifies the web
site, which is stored
on a web server.
• The Path identifies the name of the specific web
page
The End!!!