How Magnets Affect Computer Disks


One of the most commonly used Computer data storaged mediums is a
Computer Disk or a Floppy. These are used in everyday life, in either our
workplace or at home. These disks have many purposes, such as:

Storing data: Floppies can be used to store software/data for short preiods of

Transferring data: Floppies are used to transfer/copy data from one computer to

Hiding data: Floppies are also sometimes used to hide sensitive or confidential

because of the disk\'s small size it can be hidden very easily.

Advertising: Because floppies are cheap to buy, they are used to advertise
different types

of software, such as: Software for the internet advertised on America Online

Floppies are also considered to be very sensitve data storage mediums.
These Disks have numerous advantages and disadvanteges. Even though floppies are
used so commonly they are also not very dependable. They have numerous
conditions under which they should normally be kept. For example: the actuall
magnetic disk inside the hard cover of the disk must NEVER be touched, the
magnetic disk inside, must be protected by the metallic sliding shield, the disk
must always be within the temperature of 50° to 140° Fahrenheit and the disk
must never be bought near a magnet! (3M Diskettes)

There are many such hazards to computer disks. Problems caused by
magnets are very common. A floppy can be damaged unknowingly if it is kept near
a magnet, that may be in the open or inside any device, such as a speaker phone
in computer speakers or stereo or a telephone. And becuase of the common use of
magnets in everyday life, more and more floppies are damaged everyday.

Even though protective coverings against magnets and other electrical
hazards, are available for floppies, they are not used very commonly. Therefore,
floppies are not a very safe media for storage, even though they are convienient.

Some of the most commonly used diskettes are by 3M and Sony and other
such companies. The floppies are sold in boxes with instructions on them to not
to bring floppies near magnets and other instructions of DOs and DONTs. These
instructions must always be followed.

Floppies have different capacities such as 720 KB (kilobytes) and 1.44
MB (megabytes). Floppies also have different sizes, 3.5" and 5.25". The most
commonly used floppy is usually 3.5". It is not soft and cannot be bent, where
as a 5.25" disk is soft and can be bent!

A floppy is a round, flat piece of Mylar coated with ferric oxide, a rustlike
substance containing tiny particles capable of holding a magnetic field, and
encased in a protective plastic cover, the disk jacket. Data is stored on a
floppy disk by the disk drive\'s read/write head, which alters the magnetic
orientation of the particles. Orientation in one direction represents binary 1;
orientation in the other, binary 0.


The purpose of my experiment was to test Floppies to see how delicate
they are near magnets and how much damage can be done to the disks and to the
software on it bye a single magnet. I also hope my project will help others to
be aware that computer disks are very delicate and sensitive to temperature,
weather, magnets...etc.


When the magnets are bought near the disk, the disk should be damaged
internally along with the software in it. And the weakest magnet should cause
the least damage and the strongest magnet should cause the most damage.


Four 3.5" Floppy Diskettes.
Four different Magnets
One Personal Home Computer
Norton Disk Doctor
Dos (Ver 4.00.950)


Every Floppy Diskette has 2874 sectors. This was calculated by dividing
the total number of bytes on a disk by the number of bytes every sector occupies.
There is a total of 1,457,664 bytes on every Floppy, and every sector occupies
512 bytes. Therefore, 512 / 1457664 is 2874, ie. the total number of sectors on
every Floppy.

First, I obtained the four 3.5" IBM formatted floppy diskettes (Highlandä
). Next I obtained the four different magnets of different strengths and sizes
and tested and verified their strengths by bringing iron filings near each of
them and observing how much of iron filings each one of them attracted and then
noting which magnet was the strongest and which was the weakest in order. Then I
tested each of the disks for existing errors by using a program called Norton
Disk Doctor (NDD) which has the ability to detect and fix error on a disk. There
were no error on any of the four disks.

Next, I decided to hold the magnets near the disks for the