CD-ROM

27/09/06

* a CD-ROM is an item which you can store information onto
** just like light bouncing off shiny surfaces, a so called laser inside the CD player bounces off the shiny parts of a CD
*** a CD can hold about 700 mega bytes of data
**** while a DVD can hold up to 4.7 to 8 giga bytes of data
***** both CD and DVD are both of optical media

Three layers of a CD

* shiny layer
** plastic layer
*** metallic layer

^-^ Metallic layer is the part which all the data is stored as a pit
^-^ once again the computer uses binary to read data from the CD
^-^ binary numbers are 0 and 1's, there is a pit then it's 1, and if there's not then it's 0

Scratching a CD

* you should be really careful not to scratch your CD, because when you do that it defuses light
** when it defuses light it makes hard for the computer to read the data stored onto the CD
*** but Mr. Case taught us a way to fix the scratch
***** you can fill in the scratch by rubbing toothpaste on it starting at the middle and doing it outward
****** I don't know if it actually works but I' am going to try it on my brother's CD, so even if it doesn't work I won't really care

ROM

* stands for read-only-memory
** that means you can only read it and cannot write anything on it
*** also means that after you have saved something on it, you can't edit it
**** CD's and DVD's are some of the common examples of ROM

Ways to save data

* CD
** Floppy Disk
*** USB Key

Facts

* When you remove the battery from the motherboard and put it back on, all the settings in the BIOS chip will change (battery in the motherboard is what makes the BIOS work)
** But if you pull the battery off of some of the new PDA's the settings won't change
*** when your CPU becomes really hot, the computer will immediately shut off.
**** so it will be better if you have a fan in your CPU (Central Processing Unit)
***** a hard drive is a magnetical media