First 298 words of the document:
This is data storage which retains its contents when the computer is switched off
It is slower to access secondary storage than internal memory.
Data in internal memory is lost when the computer is switched off.
Types of secondary storage:
o Stores binary data on a disk/tape different parts magnetised to store 0/1
o Stores binary through reflection/non reflection of light
o Stores binary on material where areas act as open/closed switches
One example of a magnetic storage device is a hard drive. Platters rotate while a
read/write head moves to load and save data. A hard drive is used to store the OS,
applications and files.
Very fast access to data
Random access means data can be read from any part
If the data is not backed up elsewhere, it will be lost when the drive
Another form of magnetic storage is magnetic tape. The tape is written to or read
from when it passes the heads. You have to start at the beginning of the tape (serial
access) when searching for data. This tape is commonly used to backup data.
Large storage capabilities
Serial access makes data access slow
A CDROM is a type of optical storage device. It is slower to access than a hard
drive but faster than a floppy disc.
Large quantities of data can be stored
CD drives are common in PCs
Files cannot be saved on a CDROM
If scratched, they can stop working