Microsoft Office Tutorials and References
In Depth Information
ROM boot program activated
supply to the
Complementary metal oxide semiconductor (CMOS) memory (pronounced “SEE-
Moss”) is another chip that is installed on the motherboard. It is also activated during the
boot process and contains information about where the essential software is stored. A
small rechargeable battery powers CMOS so its contents will be saved between computer
uses. Unlike ROM, which cannot be changed, CMOS must be changed every time you
add or remove hardware to your computer system. Thus, CMOS is often referred to as
semipermanent memory, ROM as permanent memory, and RAM as temporary memory.
Storage Devices and Media
Because RAM retains data only while the power is on, your computer must have a more
permanent storage option. As Figure 17 shows, a storage device receives data from RAM
and writes it on a storage medium, such as a disk. Later the data can be read and sent
back to RAM to use again.