Definition: Backing storage devices are hardware that is used to store the programs and data that the computer can access. Unlike RAM (or working) memory the contents of backing storage will not be lost when power to the computer system is turned off.
There are three types of backing storage hardware we need to know about:
Storage Media is a term used to describe the different categories of backing storage devices on which software and data is saved. The following sections dealing with hard disks, floppy disks, magnetic tape, CD's, DVD's and flash drives are all examples of different types of backing storage media.
|Hard disk drives use random/direct access to locate data stored on the disk.|
Floppy disks are disks of plastic coated in magnetic material and enclosed in a hard plastic case. The read/write area is covered by a sliding metal flap.
Although, they used to be very common, as they were a convenient way of transporting files from one computer to another, they not much used anymore.
Floppy disks are written to and read from, through the use of separate floppy disk drives.
Floppy disks are less popular than they have been because :-
Are very similar to floppy disks. Again they are plastic discs coated with magnetic material. The difference between them is that zip disks can store much more. The one shown stores 100MB and you can get them up to 250MB.
Like Floppy disks, zip disks need a specialised zip drive to read and write to the disk.
Made of a long plastic strip coated with magnetic material, tape is mostly used for making backups. It can store lots of data, but this data is slower to access, because of having to wind through to the information you need slows down he access time. This makes it impractical for use as main storage
One great advantage of magnetic tape is its cheapness.
Magnetic tape uses sequential or serial access to locate data stored on the tape.
What you have to do!
Watch the videos above and in your Word document or your Brain complete the following exercises.
Provide three advantages to using hard disks as a backing storage device.
Why are floppy disks no longer so widely used?
Provide an example of backing storage that uses sequential access to data.
What you should be able to do!