Welcome to the second session of Basic Computers.
Here’s how you can use the Computer Lab (for example) to your benefit.
Suppose you’re using a computer here at the library.
You write a long letter to your congressman. Later on in another class we’ll talk about word processing.
But for now, let’s assume you’ve written the letter.
You realize that time is running out and you need to leave, but you want to make changes in the letter later on your computer at home.
But, OH NO, you already saved it to the hard drive and closed down the program!
What to do? Here’s the answer..
You have a disk. You pop it into the drive.
Make sure it’s in there correctly now. The round piece of metal in the center faces DOWN!
Let’s make sure there’s enough room on it for our purpose.
Open the disk through MY COMPUTER
Look at the bottom of the disk window.
See the amount of disk space used?
Now, back to the C: drive. What did we name that thing? Oh yes, here it is.
Have you ever heard the term DRAG AND DROP?
Here’s what that means.
Put the curser (arrow) from the mouse over the file in the hard drive,
hold down the left button and physically move the entire mouse
until the curser is inside the floppy drive window. Release the mouse
Now look at the A: drive. The file has been copied over to it.
Now we can delete the file from my computer and you can take it home
or to a friend’s computer to work on it some more.
Now, let’s look inside one of these things to see what’s in it.
The most important item in here is the motherboard, into which is plugged everything else, either directly or otherwise.
There’s the CPU. (Upper right corner, dark)
All those other switches and chips make the other parts of a computer run.
Throughout the board is a line (wire) connecting everything, this is called the bus.
Everything rides the bus, but not necessarily at the same time.
Also, everything added to a computer like a modem, mouse or printer,
must tell the CPU it’s ready to go to work (on the bus)
and it does this by sending a signal.
Each of these devices has its’ own signal.
If more than one signal is received at the same time, problems may occur.
If you’ve ever had a problem with a sound card and a printer, that’s why.
These signals are called interrupt requests, or IRQ.
Otherwise means that if it’s not plugged into the motherboard it’s plugged into another smaller card
which in turn is plugged into the motherboard.
Can you see the connectors in the very front of the motherboard?
If you look at the back of your computer
you'll see them.
The type of card determines the function it performs. One type of card gives you the ability to plug in your monitor.
Another one allows you to plug a phone line into a wall outlet.
That's what a MODEM looks like!
Here's an older card
Note how big it is compared to the newer cards in the next picture.
Here’s the floppy drive which, today is capable of storing almost (1.44) 1.5 megabytes of information on a disk.
This amounts to about 1500 pages of text!
There are other disks which can hold 250 megs of information.
They are called zip drives
Here is the fixed disk or hard drive which can hold gigabytes of information.
A gigabyte is a billion bits of information.
Look at that older hard drive on the left.
Two of the newer versions (next to it) hold much more information but notice how very small they are.
That's why computers generally are smaller than earlier models.
The internal parts are so much more compact!
The next denomination you will hear soon is a TERABYTE.
One trillion bits of information!
A CD-ROM would fit in here.
That means compact disk-read only memory. 
Back in the old days of computering, 2 or 3 years ago,
you could not store any information on a CD. Now, of course, that is possible with a WRITEABLE CD.
You can play a game, create a document or listen to your favorite music through this media.
That's because there's a sound card inside the box.
Here is the video card. It is the connection between the monitor and the CPU.
Here’s where the keyboard, and mouse are plugged in. A modem could be connected here.
You can upgrade pretty much everything inside the box, and memory is probably the first thing people add.
The different sizes denote various amounts of memory.
If you buy a program, look on the side of the box. It will state how much memory is needed to run the program.
Don’t buy it unless you either have enough memory or you plan to add more.
At our next session we’ll discuss being on-line, what that means,
and how to find virtually any information in the world,
right from your computer!
KEWL? See ya!