How do they make computer discs?

Let's ask Pierre Kerr, ac210@freenet.carleton.ca, how computer discs are made.

There are a few different kinds of computer discs (or disks). I've given you an example of one kind of disk, a floppy disk.

This one is an old 8 inch floppy disk from IBM. The first disk drives were invented by IBM and looked very much like these 8 inch floppy disks. Later they invented the hard disk. This one is called floppy because it can bend a little bit. You shouldn't bend it too much but this one is not used anymore so you can do what you like with it. I have cut the end of the case off so you can slip out the shiny brown disk that's inside. That disk turns around very quickly when it's in the computer.

Floppy disks work because they can store information as very small magnetic signals. The brown plastic that makes the disk is the same material that is used in audio cassettes and video tapes.

There are other sizes of floppy disks such as 5 1/4" and the most common these days, 3 1/2".

There are also hard disks. These are normally inside a computer so you can't see them. They still use the same brown material to store the magnetic information but it is on a hard surface such as aluminium. When it is turned on it will spin very quickly. When this is in a computer, you wouldn't be able to see the disk part at all.

Show the disks to the other students on your class and perhaps you would like to set them up on a table so everyone can see them. They're yours to keep. They don't work anymore since they're quite old.

Also, in your Library, the scientists have a hard disk on display with the cover off along with a complete computer so that you can see inside.

Thanks for the question.

€ƒÂ„ÂHow do they make computer discs?

Bobby, Rose Rebecca, room 11, Mrs. Pottery