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Optical Storage
	CD DVD
Store datra by:	microscopic light (lands)on the disk surface dark spots (pits)on the disk surface
Read data by using:	a laser light hight-powered microscope
Useful life:	estimated more than 200 years
Advantages:	Density for exceeds coated with a clear plastic less susceptiable to environmental damage faster than floppy disk

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ROM-Read Only Memory
ROM	Read-Only Memory
Funtion	Containing instructions -help a computer prepare to process tasks
Location	Plugged into the motherboard
Storage	Permanent and Non-volatile
The way to change the instructions	The only way is to replace the chip

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CMOS Memory
CMOS Memory	Complementary metal oxide semiconductor memory
	powered by a small battery (battery can automatically recharges)
Funtion	holds data
Location	In motherboard
Storage	more permanent than RAM less permanent than ROM
The way to change the instructions	can change settings by - CMOS setup-program

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ROM-BIOS
ROM BIOS	Basic input/output system
Funtion	tell the computer how to access the hard disk find the OS( operating system) load it into RAM Test the CPU Test The memory Initialize and test the hardware and Chipset on the mother board.
Location	In Motherboard
The way to change the instructions	by a special program - BIOS update program and the new version of BIOS

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