Kids Domain Computer
Connections
Computers Inside & Out
Lesson 1
Lesson 2
Lesson 3
Lesson 4
Lesson 5
Lesson 6
Lesson 7
Lesson 8
Lesson 9
Lesson 10
Lesson 1: Outer Hardware
Take a look at the computer in front of you.
No, not just the screen. Look at all of the other parts. Do you know what they
are? Do you know what they do? If you already know - great! Give yourself a big
pat on the back! But if you don't know about all the gadgets surrounding your
computer, then read on and find out!
The Basics
Lets
start with the center of any computer system. Do you see something shaped like a
box nearby? It will have a power switch and a light or two. It should also have
a place or places to insert disks. This is the case that houses all of the
important computer components. If it stands up tall, it is a tower case.
If it sits flat, it is a desktop case. Ask your parents to let you look
at the back of the computer (never do this without permission, because there is
a lot of dangerous electricity back there!). You will see lots of cords and
cables coming out of the back of the case and going to other computer parts like
the monitor.
Your computer case probably has a place to insert floppy disks or CDs. These
are called the floppy disk drive and the CD-ROM. The floppy disk
drive reads information from a very thin disk that is inside a flat, square
plastic case. You can also write information to these disks and 'save' it.
CD-ROM is short for Compact Disk - Read Only Memory. A compact disk is a shiny,
circular disk that stores information. A CD-ROM can only read information from
the disk. Many new computers have a CD-RW (RW stands for ReWrite) instead
of a CD-ROM. CD-RW allows you to write information to the disk as well as read
from it. Also, some new computers have a DVD (Digital Video Disk) drive
instead of a CD-ROM or CD-RW. A DVD looks just like a CD, but it holds much more
information. You can watch movies, listen to music, or play computer games from
DVDs. One important thing to know is that you can play CDs in a DVD player, but
you cannot play DVDs in a CD player!
Input Devices
There are several ways to get new information or input
into a computer. The two most common ways are the keyboard and the mouse.
The keyboard has keys for characters (letters, numbers and punctuation
marks) and special commands. Pressing the keys tells the computer what to do or
what to write. The mouse has a special ball that allows you to roll it around on
a pad or desk and move the cursor around on screen. By clicking on the
buttons on the mouse, you give the computer directions on what to do. There are
other devices similar to a mouse that can be used in its place. A trackball
has the ball on top and you move it with your finger. A touchpad allows
you to move your finger across a pressure sensitive pad and press to click.
Other types of input devices allow you to put images into the computer. A scanner
copies a picture or document into the computer. There are several types of
scanners and some look very different, but most look like a flat tray with a
glass pane and a lid to cover it. You can input photographs into a computer with
a digital camera. Photos are taken with the camera away from the computer
and stored on a memory chip. Then the camera is plugged into the computer, so
that the images can be downloaded. Another input device is a graphics tablet.
A pressure sensitive pad is plugged into the computer. When you draw on the
tablet with the special pen (never use an ink pen or pencil!), the drawing
appears on the screen. The tablet and pen can also be used like a mouse to move
the cursor and click.
Output Devices
Output devices display information in a way that you can you
can understand. The most common output device is a monitor. It looks a
lot a like a TV and houses the computer screen. The monitor allows you to 'see'
what you and the computer are doing together. 
Speakers are output devices that allow you to hear sound from your
computer. Computer speakers are just like stereo speakers. There are usually two
of them and they come in various sizes.
A printer is another common part of a computer system. It takes what
you see on the computer screen and prints it on paper. There are two types of
printers. The inkjet printer uses inks to print. It is the most common
printer used with home computers and it can print in either black and white or
color. Laser printers run much faster because they use lasers to print.
Laser printers are mostly used in businesses. Black and white laser printers are
the most common, but some print in color, too.
Lesson 2: Hardware on the Inside
Computers are made of many electronic components
or parts. These components each have a special job and they all work together to
make your computer operate. Some components are hidden inside the computer,
where you can't see them. Others can be seen partly from the outside.
Power It Up!
Every computer needs a power supply, to take
electricity from your house and convert it into a current that works for your
computer. The electrical cord that comes out of your computer, comes out of the
power supply. When it is plugged into the wall, electricity travels from the
electrical wires in your house into the computer's power supply. When your
computer is turned on, the power supply allows the converted electricity to
travel to other components inside the computer.
Circuits
The motherboard
gets its name because it is like a mother to all of the other circuit boards.
Found at the bottom of a desktop case or the side of a tower case, the
motherboard is the largest circuit board and has many smaller boards plugged
into it. It holds all of the most important parts of the computer.
On the motherboard, you will find several expansion cards. Each of
these cards has a special purpose. The sound card contains special
circuits for operating the computer's sound. The video card handles
graphics that are displayed on the monitor. There are also expansion cards for
other computer components including the drives and ports.
The modem is an expansion card that allows computers to talk to each
other. A modem plugs the computer in to a phone or cable line so that
information can be transferred between computers. Current modems can run up to
56,000 bits per second. Don't know what a bit is? Don't worry, we'll get to that
in a later lesson :)
The brain of a computer is the CPU or Central Processing Unit.
Like a brain, it controls information and tells other parts what to do. The type
of CPU in a computer also determines how fast that computer can operate. A CPU
generates lots of heat, so there is usually a small fan nearby to cool it down.
A very important computer component is the BIOS chip. BIOS stands for Basic
Input Output System. In very simple terms, the BIOS chip wakes up the
computer when you turn it on and reminds it what parts it has and what they do.
RAM & ROM
Have
you ever heard the terms RAM and ROM? These two terms sound very
similar and can easily be confused by beginners. However, understanding what
they mean and what they do can help you to remember.
RAM stands for Random Access Memory. RAM chips will remember what you
tell them and can even change to remember new information. But, when the
computer is turned off, RAM forgets everything you told it. This is why it is so
important to save your work on a computer - if the computer gets turned
off, RAM will lose all of your work!
ROM stands for Read
Only Memory. ROM is good at remembering, but cannot change it's mind. It
holds information that is built into it. ROM is like reading a library book -
lots of information is there, but you can't change it (because you never
write in a library book). RAM, on the other hand, is more like a journal - you
can write information into the journal. But if you change your mind, you can
erase and write in new information.
Ports
Ports are the places on the outside of the computer
case where you plug in hardware. On the inside of the case, they are connected
to expansion cards. The keyboard, mouse, monitor, and printer all plug into
ports. There are also extra ports to plug in extra hardware like joysticks,
gamepads, scanners, digital cameras and the like. The ports are controlled by
their expansion cards which are plugged into the motherboard and are connected
to other components by cables - long, flat bands that contain electrical
wiring.
Disk Drives
Disk drives read information off of storage disks.
The three most common disk drives are the hard drive, floppy disk drive and
CD-ROM. In lesson 1, you learned a bit about the latter two, which are usually
installed inside the front of your computer case so that you can get to them
from the outside to load the software. The hard drive, however is hidden
inside the computer because the disks are not meant to be removed. Information
that you save on your computer is stored on these hard disks. You can learn more
about storage disks in Lesson 4: Storage; but first, check out Lesson 3 to learn
about bits and bytes.
Lesson 3: Bits & Bytes
Did you know that all of the
information that travels through your computer is based on two commands? It's
true. The only data that a computer can understand is on and off.
But, the millions of combinations of those two commands given in series are what
make a computer work.
Binary Code
Remember
the power supply that is inside your computer and how it sends electricity to
all of the components? That electricity is what creates an on signal. The
memory chips inside your computer are divided into thousands of tiny
compartments called bits. Each bit has an electronic switch or gate.
On means the gate is open and letting electricity go through. The
computer reads on or open switches as a number 1. Closed
gates are off because the electricity is blocked and cannot get through.
The computer reads off bits as 0. It is by grouping these bits
together to form a series of 1/0 commands, that data is formed. Eight
bits are grouped together to form a byte. In this group of eight, there
are 256 possible combinations of 1/0. The grouping of 1/0 within a
byte is called Binary Code.
Here's an example
of the Binary Code in action: When you type the letter A on your
keyboard, electrical signals are sent from the keyboard to the CPU. The CPU
turns the signals into binary code. Then, the computer reads the code and sends
it on to the monitor to display the letter A.
KB, MB & GB
You may have seen these abbreviations many times before. Do
you know what they mean?
- KB = kilobyte = about 1,000 (one thousand) bytes, (1024 or 2^10)
- MB = megabyte = about 1,000,000 (one million) bytes, (1,048,576 or 2^20)
- GB= gigabyte = about 1,000,000,000 (one billion) bytes (1,073,741,824 or
2^30)
As you can see, these abbreviations stand for a specific number of bytes. And
each byte holds 8 bits capable of forming 256 combinations of 1/0. Wow!
The number that comes before one of these abbreviations represents the
computer's memory capacity. For example, if a computer has 64MB of RAM
that means that the computer can handle 64,000,000 (64 million) bytes of random
access memory (that's 64,000,000 microscopic 8-bit panels). Hard disk space is
also measured in bytes. So, a 15GB hard drive has 15,000,000,000 (15 billion)
bytes for storing memory.
Look at your keyboard. Each character key is represented by a number that is
held in a single byte. Remember how the letter A is sent to the CPU to be
translated into binary code? The numerical value of the uppercase letter A
is 65. That number 65 is represented in one byte - a combination of 1 and
0 or on and off switches. The computer cannot understand
letters, so it translates them into numbers that are represented by patterns of on
and off. To get an idea of how much on/off data a computer can store,
just imagine pressing one key one billion times! How long would it take? If you
pressed the key 5 times per second, it would take you over 6 years of
continuously typing to reach 1 billion keystrokes equal to 1GB of memory! And
many computers today can store over 20GB of memory on their hard disks!
Incredible! So, the next time your computer is taking a long time to load a web
page, think of how fast it really is going!
Lesson 4: Storage
The purpose of storage in a computer is
to hold data or information and get that data to the CPU as quickly as
possible when it is needed. Computers use disks for storage: hard disks that are
located inside the computer, and floppy or compact disks that are used
externally.
Hard Disks
Your computer uses two types of memory: primary memory
which is stored on chips located on the motherboard, and secondary memory
that is stored in the hard drive. Primary memory holds all of the essential
memory that tells your computer how to be a computer. Secondary memory holds the
information that you store in the computer.
Inside the hard disk drive case you will find circular disks that are made
from polished steel. On the disks, there are many tracks or cylinders.
Within the hard drive, an electronic reading/writing device called the head
passes back and forth over the cylinders, reading information from the disk or
writing information to it. Hard drives spin at 3600 or more rpm
(Revolutions Per Minute) - that means that in one minute, the hard drive spins
around over 3600 times!
Today's hard drives can hold a great deal of information - sometimes over
20GB!
Floppy Disks
When you look
at a floppy disk, you'll see a plastic case that measures 3 1/2 by 5 inches.
Inside that case is a very thin piece of plastic (see picture at right) that is
coated with microscopic iron particles. This disk is much like the tape inside a
video or audio cassette. Take a look at the floppy disk pictured. At one end of
it is a small metal cover with a rectangular hole in it. That cover can be moved
aside to show the flexible disk inside. But never touch the inner disk - you
could damage the data that is stored on it. On one side of the floppy disk is a
place for a label. On the other side is a silver circle with two holes in it.
When the disk is inserted into the disk drive, the drive hooks into those holes
to spin the circle. This causes the disk inside to spin at about 300 rpm! At the
same time, the silver metal cover on the end is pushed aside so that the head in
the disk drive can read and write to the disk.
Floppy disks are the smallest type of storage, holding only 1.44MB.
How Hard and Floppy Disks Work
The process of reading and writing to a hard or floppy
disk is done with electricity and magnetism. The surfaces of both types of disks
can be easily magnetized. The electromagnetic head of the disk drive records
information to the disk by creating a pattern of magnetized and non-magnetized
areas on the disk's surface. Do you remember how the binary code uses on
and off commands to represent information? On the disk, magnetized areas
are on and non-magnetized areas are off, so that all information
is stored in binary code. This is how the electronic head can both write to or
read from the disk surface.
It is very important to always keep magnets away from floppy disks and away
from your computer! The magnets can erase information from the disks!
Compact Disks
Instead of electromagnetism, CDs use pits
(microscopic indentations) and lands (flat surfaces) to store information
much the same way floppies and hard disks use magnetic and non-magnetic storage.
Inside the CD-Rom is a laser that reflects light off of the surface of the disk
to an electric eye. The pattern of reflected light (pit) and no reflected light
(land) creates a code that represents data.
CDs usually store about 650MB. This is quite a bit more than the 1.44MB that
a floppy disk stores. A DVD or Digital Video Disk holds even more information
than a CD, because the DVD can store information on two levels, in smaller pits
or sometimes on both sides.
Uses of Floppy Disks
You might wonder: If all the information is stored safely
inside my computer, why would I need to store it outside? There are several
reasons why portable storage is so important.
Floppies make it possible to backup important information in case it is lost
by the computer. Do you remember in Lesson 2, we talked about RAM and ROM? RAM
loses its memory each time the computer is turned off, but ROM keeps information
stored even when the computer is not turned on. Well, sometimes computers have
problems that can cause them to crash. No, that doesn't mean they jump
off the desk and smash on the floor ;-). A crash is something that happens
inside the computer's circuits and can make it forget things. Some crashes can
even make ROM forget everything! Having important information backed up on disks
will allow you to put it back into your computer's memory. Backup disks can save
you lots of time and headaches!
Disks also allow information to be transferred between different computers.
Let's say that you are working on a project using a computer at the library, but
you don't finish it by closing time. There's your project sitting in the
computer. How do you get it home to finish it on your computer? You write the
information to a disk, take it home and upload the information into your
computer from the disk. What an easy way to transfer information!
Uses of Compact Disks
The most common use for compact disks (aside from playing
music) is storage of software programs. When you purchase a computer game, the
program that tells your computer how to run the game is stored on a CD. You move
the program into your computer's memory by installing it. Some programs are
transferred completely into your computer's hard drive. However, many programs
are very large and would take up lots of memory space on your hard drive. To
keep that from happening, these programs are designed to only upload part of the
program onto your computer. The rest of the program stays on the software. The
program cannot be run from your computer unless you have the CD in the disk
drive so that RAM can read the rest of the program from it.
With the introduction of CD-RW (disk drives that can write to compact disks
as well as read from them), CDs can now be used for storage much like floppies.
Using a CD-RW, computer data can be backed up to a CD. All kinds of information
that was too large to fit on floppy disks can now be saved on CD. Many people
store music files or family photos on CD.
Lesson 5: Programs
Programming
In
Lesson 3, you learned that all of the information that travels through your
computer is stored on bits as either an on or off signal. Using bits and bytes
in different combinations to represent a code is known as programming.
These codes allow the computer to understand instructions. Computer
programmers are people who write these codes to create programs. There are
even programming languages that make it easier, so that these people
don't have to remember all the bit or byte combinations. Programming allows
people and computers to communicate more easily.
Computer Programs
A program is a set of instructions that tells the
computer how to perform a specific task. For example, your favorite computer
game is a program. In order for your computer to know how to play that game, you
(or your parents) must first install the program from the game software -
usually a CD. Installing the program means that you are copying the program or
instructions that are stored on the CD on to your computer's hard drive.
Programs can also be downloaded from the internet directly to your hard drive.
Many programs (especially games) are very large and would take up lots of
memory space on your hard drive. To keep that from happening, these programs are
designed to only copy part of the program onto your computer. The rest of the
program stays on the software. The program cannot be run from your computer
unless you have the disk in the disk drive so that RAM can read the rest of the
program from it.
Other programs install completely on your hard drive, so that they can be
used without running the CD. This is very helpful with programs that are
designed to help the user perform a specific task, such as typing a letter or
creating a birthday card. Having the program run without the CD, frees up the
CD-ROM drive in case you might need to run a clip art CD to add some pizzazz to
your creation!
Types of Programs
There are many different types of programs for the computer.
They are grouped according to the tasks that they perform. Here are some very
common types of programs and some examples of their uses:
- Word processing - letter writing, essays, writing stories
- Database - address books, mailing lists
- Spreadsheets - storing financial information
- Research - encyclopedias, informational programs
- Entertainment - games, music/video programs
- Education - skill practice games, tutorials, how-to programs
- Desktop Publishing - creating birthday cards, newsletters, etc.
Programs do much of the
work for us, when we perform tasks on the computer. The program instructs the
computer in a language that it understands. Think of how hard it would be to
dictate a story for someone else to type if that other person spoke a foreign
language! You could learn that person's language, but that could take years. The
easiest way would be to have a translator. Programs are like translators that
allow people to work with computers without learning the computer's language.
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Lesson 6: Operating Systems
What
is an Operating System?
The most important program on any computer is the Operating
System or OS. The OS is a large program made up of many smaller
programs that control how the CPU communicates with other hardware components.
It also makes computers easier to operate by people who don't understand
programming languages. In other words, operating systems make computers user
friendly.
Do you remember ROM (Read Only Memory) and RAM (Random Access Memory) from
Lesson 2? ROM and RAM are very important to the OS. Part of a computer's
operating system is built into ROM. That part contains the most essential
programs that the computer needs in order to run correctly. 
The ROM operating system is also known as the BIOS (Basic Input Output System).
You may remember from Lesson 2 that the BIOS is responsible for waking up the
computer when you turn it on to remind it of all the parts it has and what they
do.
The operating system also contains other programs that are important, but not
essential to making the computer run. The part of the operating system that
contains these programs is stored on a computer's hard drive and is booted to
RAM whenever the computer is turned on. This part of the operating system is
known as DOS which stands for Disk-based Operating System.
Types of Operating Systems
Different computer manufacturers use different operating
systems. Apple has specific operating systems for its line of Macintosh
computers. When IBM released their Personal Computer or PC back in the early
1980's, they did not get a copyright on it, which allowed many other companies
to build similar computers that were IBM-compatible; in other words, they used
the same operating system as the IBM PC. There are different operating systems
available for PCs, but the most common is Windows, which was developed by a
company named Microsoft. Windows is similar to the Macintosh operating system,
because it also uses a mouse and a GUI (Graphical User Interface) that
uses graphics or pictures to help the user navigate within the computer
system.
There are several versions of Windows (95, 98, NT, 2000), just as there are
several versions of Macintosh operating systems (System 7, System 8). Operating
systems are constantly being improved or upgraded as technology advances.
When a company thinks that their operating system has been advanced enough from
the one already on the market, they release their new version for sale. Users
can then purchase the new version and upgrade the part of the operating system
that is stored on the hard drive. The ROM OS is not affected by the upgrade.
Upgrading an operating system can have several advantages, such as simplifying
tasks and navigation. However, there can be disadvantages, too. Many Windows 95
users upgraded to Windows 98 and discovered that many of their older programs
would no longer run within the new operating system.
The Computer Revolution
The introduction of the Macintosh OS and the later
introduction of Windows played a large part in making computers accessible to so
many people. The user-friendly interfaces of both operating systems made it
easier for people with no computer training to learn to use these amazing
machines. Other machines, such as typewriters and payroll calculators quickly
became a thing of the past, as computers became so easy to use and so
affordable.
Lesson 7: Files & Folders
Computer hard drives hold an enormous amount
of data or information. It is very important that all of the data is well
organized. That way it is easy for the computer to find what it is looking for.
Knowing how a computer's organization system works will help you to find
what you are looking for. Computers use files and folders to organize data.
What is a file?
A file is a collection of data that is stored
together. Files can be stored on a hard drive, a floppy disk, or a CD.
Everything that a computer does is based on data stored in files. You can do
lots of things with files - create them, name them, rename them, save them, or
delete them. Certain files can even be looked at, listened to, and run.
In some ways, files are like television shows. All TV shows have 3 things,
just like computer files:
Just as you recognize your favorite TV program by its name, you can also
recognize a file by its name. File names often consist of 2 parts: name and
type. There are many different types of TV shows - comedies, dramas, cartoons,
sports shows, game shows, etc. Similarly, computer files come in different types
- text files, graphic files, program files, email files, etc. In many computer
systems, files are named so that you know what type of file it is just by
looking at the abbreviation behind the name. A period is used to separate the
name from the type, like this: "name.type". If TV show titles came in
2 parts like computer files, they would give the name of the program, followed
by a period, followed by the type of show it is. It might look like this: "Sillykids.toon"
or "EmergencyRoom.drama" or "Football.sport"! One important
thing that you should know about file types or extensions is that they
are always written as abbreviations, usually with 3 letters. For example, a text
file is shown as .txt and an executable program file is shown as .exe.
You may not always see the extension on a file name, because many PCs offer the
option of turning off the extension. Even though you don't see it, the computer
still does. On the Macintosh system, however, the practice of naming files with
extensions is not always followed; but you can see what kind of file it is by
the icon or 'kind' identifier in the directory listings. Common Mac extensions
you'll see are .sit (a compressed stuffit file), .hqx (a binhexed encoded file),
.pdf (Adobe Acrobat file). Web pages (no matter what system) always use
extensions to identify the kind of file - .htm or .html for the web pages, .gif
for gif graphics, .jpg for jpg graphics and so on.
Files are stored in certain places within your computer, much like TV
programs are shown on certain channels. So, to find a file you must know where
it is located, just like you must know on what channel to find your favorite TV
show. If you forget what channel a TV show is on, you can either flip through
channels until you find the program or you can look in a TV guide to find the
information you need quickly. The quickest way to find files on most computers
is to use Find. This is a type of search program where you can type in
the name of a file and the computer will search and tell you where the file is
located. If you use a Windows Operating System, Find is located on your Start
Menu. On a Macintosh System, Find… is located under File on
the menu bar. (More on Start Menu and menu bar in Lesson 8).
TV Programs, like files, have specific lengths. TV shows may be 30 minutes
long, 1 hour long, or several hours long. Files are not measured in time, but in
bytes. If you'll remember from Lesson
3: Bits & Bytes, a byte is a measurement of stored data. Larger files
may be measured in kilobytes or megabytes. The length of a file tells how much
storage space that file is using within the computer.
Folders or Directories
With so many thousands of files stored inside a computer, it
is very important to keep them organized. Folders, also known as Directories,
keep files organized by grouping them together.
Imagine for a moment that you had a giant toy room filled with toys and you
were given the job of organizing all of those toys. You decide to start the job
by sorting all of the toys and grouping similar toys together. For example, you
put all of your red marbles in a box and all of your blue marbles in another box
and all of your clear marbles in another box. Then, you put all of those boxes
into a bigger box and label it "marbles". Then, you might even put the
"marbles" box into a bigger box that contains boxes of "super
balls" and "tennis balls" and "baseballs". You would
name that big box "balls". If you continued to organize toys that way,
you would end up with an entire room of boxes with labels that contain similar
kinds of toys. Then if you needed to find your plastic brontosaurus, you would
know to open the box labeled "toy animals" and go past the "bug
box" and the "reptile box" until you find the "dinosaur
box" - open it and there is the brontosaurus! In this example, the toys are
like files and the boxes are like folders. Your computer is set up to store
similar files in specific folders. Then similar folders can be put inside other
folders, and so on.
Many times, the computer will automatically store files in certain folders in
order to keep itself organized. However, when you create new files, you must
decide which folders to put them in to keep them organized. You can even create
new folders to store your files. For example, let's say that a boy named Adam
wants to make a folder of all the fun things he creates on the computer. With an
adult's help, Adam creates a folder titled "Adam". Within that folder,
he creates 3 new folders titled "stories", "drawings" and
"jokes". Then, when Adam writes a story called "Alien Tap
Dancing", he stores or saves that file that contains the story in
the "stories" folder. On a PC, the file name would be "Alien Tap
Dancing.txt" because it is a text file.
The best way to keep up with a file is to know its address. The address
basically tells you what drive and folders to look in for a file. For example,
the address for Adam's story might look like this on a Macintosh system:
"Macintosh HD\Users\Adam\stories\Alien Tap Dancing" (Macintosh HD
indicates the hard drive). On a PC, the address might look like this:
"C:\\My Documents\Adam\stories\Alien Tap Dancing.txt". In this case,
the letter "C" indicates the hard drive, as most PCs assign a letter
to each drive in the system. Note, that the file address always includes the
drive, folder(s), and file name in exactly that order.
Be A Responsible Computer User
Understanding the relationship between files and folders,
and how they are addressed and located within your computer system is a very
important part of using a computer. Beginners should make it a priority to learn
about this early in their computer education. Never delete, move or rename a
file unless you are absolutely sure of what you are doing! A computer relies
on many files to keep itself running correctly, so changing or deleting those
files can cause major computer malfunctions! When in doubt, ask a parent,
teacher or other expert for assistance. The safest way to learn about using
files and folders is to ask for help in setting up your own personal folder,
then creating new folders and files within it.
Lesson 8: The Windows Desktop
When your computer is booted up and ready to
use, the screen you see is called the desktop. It is the background for
all programs and contains the commands needed for accessing those programs.
Desktops vary from one operating system (OS) to another, and even vary somewhat
from version to version of a particular OS. Whatever type of OS you use, it is
very important to learn how to use the desktop correctly, since it is the base
for all computer operations. The best place to learn about your particular OS is
with the user manual or tutorial included with your computer.
In this lesson, we will look at the Windows desktop only, since Windows is
one of the most common operating systems used today - particularly by students
and educators. It would be impossible for me to fully cover each version of this
OS; instead, I will try to give a basic overview of how the desktop looks and
what it does. This lesson is based on the Windows 98 desktop, so please
understand that your own desktop may be slightly different if it is a different
OS version.
Desktop Graphics
Both Windows and Macintosh systems are based on Graphical User
Interface or GUI, which simply means that the interface uses graphics
or pictures to help the user navigate and access programs. When you first turn
on a new computer, most of the screen will be plain blue or blue with a logo or
design. This background graphic is called Wallpaper. It is essentially a
backdrop for your work area. The graphic can be changed to a different pattern
or even a photo or picture by accessing "Display" in the Control
Panel.
Another important graphic feature that you will find on a desktop is an icon.
Icons are small pictures that are linked to programs. Double-clicking on the
icon runs the program or accesses the file and right-clicking accesses a menu
offering options, actions and properties. Certain icons are a permanent fixture
on the desktop. The user can put other icons on the desktop that will quickly
access programs or files - like a shortcut. Icons can be moved around on the
desktop by clicking and dragging them.
One of the most important icons on the desktop is My Computer, which
accesses drives, printers, the Control Panel and other system
applications. The Control Panel gives the user access to the computer system and
many support applications, such as "Add New Hardware",
"Add/Remove Programs" and "Accessibility Options". From the
Control Panel, you can access hardware settings for the keyboard, mouse,
printers and modem; as well as settings for the monitor display and sound.
Another important icon that you should know about is the Recycle Bin.
It has the same purpose that a real trash can does - you put things in it that
you no longer need or want. Anytime you delete a file or folder, it goes into
the Recycle Bin where it stays until the bin is emptied. Double-clicking on the
icon will open a window that will show you what is stored in the Recycle Bin.
Just like in real life, things sometimes get thrown away by accident and have to
be rescued. The Recycle Bin lets you do the same thing. If you delete something
you shouldn't have, you can find it in the Recycle Bin and restore it to its
proper place. When the Recycle Bin is emptied, everything in it is permanently
deleted. Never put anything in the Recycle Bin or empty the Recycle Bin
without permission!
The Start Menu and Taskbar
At
the edge of the screen (usually the bottom edge), you will see a long, thin bar
with a box labeled "Start" on one end and a clock on the other end.
This is the taskbar - another graphic tool that helps you to access
programs and files. You may see icons on the taskbar, too. These are called
"Quick Launch" icons that allow one-click access to frequently used
programs.
If you click on the "Start" button, a box called a menu will
appear. The menu will contain several words. Some words will have arrows next to
them that access other menus. Listed below are the basic Start-menu options:
- Programs - accesses installed programs.
- Favorites - accesses book-marked webpages.
- Documents - accesses the most recently opened documents.
- Settings - accesses system applications such as Control Panel, printers,
taskbar and Start Menu options.
- Find - searches for specific files or folders.
- Help - offers helpful topics for computer use.
- Run - user can input commands to run specific programs.
- Log Off - allows a password-protected user to log off and another to log
on.
- Shut Down - shuts down or restarts the computer.
The Start Menu can be personalized by adding and removing programs, files and
folders.
Windows (not the operating system)
Many programs and applications run within windows or boxes that can be
opened, minimized, resized and closed. At the top of each window, you will see a
title bar that contains the title of the program or folder. To the right
of the title bar are three square icons or buttons. The button on the far right
has an "X" on it and closes the window (which also closes the
program). The middle button will have one or two small boxes on it - this is the
resize button. Resizing allows the user to make the window full-screen or
smaller. The button on the left has a small line on it - this is the minimize
button. When a window is open, you will see a rectangular button on the taskbar
that displays the windows title and maybe an icon. Minimizing the window clears
it from the screen, but keeps the program running - all you will see of a
minimized window is the button on the taskbar. A raised button indicates a
minimized or inactive window, and a depressed button indicates an open or
active window. Minimizing a window is helpful if the user is temporarily
not using the program, but plans to return to it soon. To restore a minimized
window, simply click on the button on the taskbar. Also, it is sometimes
possible to have several windows open at once and lined up in a cascade,
one in front of another. In this case, the active window will always be in the
front.
In the Windows operating system, each window contains its own menu. Found
just under the title bar, the menu contains several words that will access
drop-down menus of options and actions. The menus vary from one program to
another, but here are some basic examples:
- File menu contains file items like new, open, close, and print.
- Edit menu contains editing items like undo, cut, copy, paste and clear.
- View menu contains items for changing how things appear on the screen.
- Help menu contains items to access tutorials or helpful information.
Under the menu, you will often find a toolbar - a bar of icons or options
that allow you to perform specific operations within the program.
In the main body of the window, you may find lists of folders or files or you
may be given a workspace for typing, drawing or other activities. On the right
side of the window, you may see a scroll bar. The scroll bar appears when
the window contains more information than can fit on the screen. Moving the
scroll bar up or down allows the user to see all of the information in the
window.
Learning the Basics
Learning how to use the desktop is the first step in learning to use a
Windows system. Hopefully, you can use this brief lesson as a starting point.
Remember, though, that experience is the best teacher, so do some exploring on
your own PC. Many systems include Tutorials that will teach you how to use your
system step-by-step. You'll also find some very helpful information about the
Windows desktop under the "Help" option of the Start Menu.
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Lesson 9: Knowing Your System
Now that you have a basic understanding of computer components and how they
work, let's apply this knowledge to your own system. It is important to know
your computer system's specifications so that you can purchase or download
appropriate software programs.
Read the Label
When you
are shopping for computer software - in a virtual store or a real one - it is
important to check out the program's Minimum System Requirements before
making a purchase. They will help you to determine whether or not the software
is compatible with your computer system. System Requirements will be listed
somewhere on the packaging of a software product or should be available on the
product's webpage if you are shopping online. Check out the graphic to the right
for a sample from a software package.
Requirement information will vary from product to product, but most
requirements will tell you the following:
- Operating System compatibility
- Processor speed
- RAM requirements
- available Hard Disk Space needed for installation
- CD-ROM or DVD speed
Additional requirements may be listed for:
- Monitor Display
- Video Card
- Sound Card
- Peripherals - joystick, gamepad, etc.
- Modem (for internet applications)
- Support software
Remember that the information listed covers the minimum requirements.
In other words, your system needs to have at least that much speed, memory,
space, etc. in order to run the software properly. If your system specs are
higher than the minimum requirement, then the software should run on your
system. The only caution you should have here is that some programs written for
older operating systems (particularly Windows 95) may not run on newer operating
systems.
Requirement or Recommendation?
On many software products, the manufacturer will list System
Recommendations along with Minimum System Requirements. This information
lets the consumer know that higher specs may be needed to get optimum software
performance. The program will run on a system with the minimum
requirements, but it will run better at the recommended requirements.
System Specifications
If you don't know your system specifications already, you
should be able to find them in your user guide or other paperwork from the
manufacturer. System information can also be accessed through your computer.
Although the location of this information may vary from system to system, the
most common place to find it will be in the "System" menu of the
Control Panel. Knowing this information about your system will help you make
compatible software purchases.
Lesson 10: Computer Care & Safety
Computers,
like any other piece of electronic equipment, need special care and attention in
order to perform properly and safely. There are several specialized tasks such
as defragmenting, scanning and reformatting that computer experts can do to keep
the internal system of a computer working well. However, we'll leave these tasks
to the experts for now and concentrate on some daily do's and don'ts that any
computer user should know.
A Clean Machine
This may seem like a simple topic, but computers require
special cleaning even on the outside. Keeping your system free of dust, dirt and
liquids is the first step to computer care. Your system's user guide is the best
place to find information on how to clean your outer components; but here are
some general tips that you should always remember:
- Never spray your monitor screen (or any other computer component)
with glass cleaner. Instead, spray a lint-free cloth lightly with
glass cleaner, then clean the screen. Be sure to hold the cloth away from
the computer when spraying.
- Computer components should be kept as dust-free as possible.
- Canned air or small computer-specific vacuum cleaners are an excellent way
to clean keyboards, computer case vents, or around disk drive openings.
- The rubber ball inside the bottom of a mouse may need occasional cleaning.
If the mouse does not perform correctly, check your user guide for cleaning
directions.
- Never try to remove the cover on your computer to clean inside.
Instead, take it to an authorized service technician for cleaning.
- Keep all liquids and food items away from your computer. Liquids and food
crumbs can damage delicate electronic circuits. Also, mixing liquids and
electronic components can cause serious electrical shock!
- Wash your hands before using the computer to avoid "sticky
keys."
- When in doubt about how to clean your computer system, consult your user
manual or technical support.
A Shocking Possibility
It is important to remember that your computer is connected
to electricity. If you have an Internet connection, that also means that your
computer is connected to a telephone line or cable connection. These are also
conductive connections. That means that lightning could be conducted to your
computer through any of these connections. For safety reasons, you should never
use your computer during a storm.
Many computer users purchase surge protectors to safeguard their
system. The user plugs computer components into the surge protector, then plugs
the surge protector into the wall. Just like the name implies, surge protectors
are designed to protect computers against electrical surges or lightning.
However, these devices can fail; so, it's best to stay clear of the computer
during storms.
Also, as mentioned earlier, electricity and liquids don't mix. Keep water and
other liquids away from the computer system. This includes drinks, water guns,
fish bowls and cleaning fluids.
Beware of Viruses
Viruses and worms are names for pesky computer-unfriendly
programs that can accidentally be downloaded into your system. Some are just a
nuisance, but others can crash your system and cause irreparable damage. To
avoid these nasty creatures, follow these safety tips:
- Install, use and regularly update virus software
- Never open an email attachment unless you know and trust the person who
sent it.
- Do not accept downloads from Internet sites that you don't know and trust.
If you would like to learn more about viruses and antivirus utilities, Check
out The
Virus Zoo at CNet for some great information!
Avoid Installation Marathons
Let's say that you were given several new computer games for
your birthday. Or maybe your parents just bought you a new system and you want
to load all your favorite games. Do you sit down and install all of these
programs one right after another? No! It may be tempting, but it's not a
good idea. Sometimes, installing a new program can cause conflicts within your
system. These conflicts will need to be worked out or else the program will have
to be uninstalled so that your system will work correctly. If you install 2 or
more programs before you realize there is a problem, it will be very difficult
to determine what the problem is and which program caused it. Instead, try
installing one program, then use your computer long enough to see how your
system responds to the installation before loading the next program.
Safe Computing!
Following these guidelines should help you to take good care
of your computer system, so that you can get lots of enjoyment from it.
Remember, that if you have any questions about your particular system, you
should check your user guide or contact technical support.
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