Magnetic Disk Drive

Basically, a floppy disk drive reads and writes data to a small, circular piece of metal-coated plastic similar to audio cassette tape.

• Both use a thin plastic base material coated with iron oxide. This oxide is a ferromagnetic material, meaning that if you expose it to a magnetic field it is permanently magnetized by the field.
• Both can record information instantly.
• Both can be erased and reused many times.
• Both are very inexpensive and easy to use.

A floppy disk, like a cassette tape, is made from a thin piece of plastic coated with a magnetic material on both sides. However, it is shaped like a disk rather than a long thin ribbon. The tracks are arranged in concentric rings so that the software can jump from each file easily. The diskette spins like a record and the heads move to the correct track. The write head puts data on the diskette by magnetizing small, iron, bar-magnet particles embedded in the plastic surface. The magnetized particles have their north and south poles oriented in such a way that their pattern may be detected and read on a subsequent read operation. This type of storage is a common type in all computers.  However due to the small amounts of information able to be held on a magnetic disk, technology has advanced and brought us optical disk drives.  Plastics are used because they are inexpensive to make and you can get similar conductive properties by adding the oxide layer. 

Back