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.:: ELEMENTARY DATA RECOVERY THEORY: MAGNETS & FLOPPY DISKS ::.

One of the most generally used computer data storage means is a computer disk or a floppy Disc. These are used at home or on the job. These disks have many purposes, such as:

Storage of data - Floppy Discs can be used, in order to store software/Data for short periods the da
Transfer of data - floppy Discs are used for the transfer/copy data from a computer to others.
Hiding data - floppy Discs are also sometimes used, in order to hide the sensitive or confidential data, because of the small size of the disk, which he can be very easily hidden.

Floppy disks are a quite inexpesnive medium, however until recent years were used quite extensively for storing important informaiton. Before the advent of simple office and home networking, CD-ROM's, and other efficient data transfer methods, the only way to get data off your PC was to copy it onto a floppy disk.

Although floppy Discs are so generally used, they are also not very reliable. They have numerous conditions, on which they should be normally held. E.G.: the magnetic disk actuall within the hard cover of the disk must inward be never affected, the magnetic disk, must by the metallic sliding sign be protected, must the disk within the temperature from 50° to 140° Fahrenheit always be and the disk must near a magnet be never bought!



There are many such dangers to the computer disks. The problems, which are caused by magnets, are very general. A floppy Disc can be damaged unknowingly, if he is held near a magnet, that can in the opened or that be internal each possible device, like a loudspeaker telephone in the computer loudspeakers or in the stereo or in a telephone. And becuase of the general use of the magnets in of the daily lives -, ever more floppy Discs are damaged daily.

Although protection coats are present for floppy Discs against magnets and other electrical dangers, they are not very generally used. Therefore floppy Discs are not very safe means for file, although they are convienient. Some the most generally used disks are by 3M and Sony and other one such companies. The floppy Discs in the boxes with instructions in them too to get to floppy Discs not close magnets and sold other instructions of DOS and of DONTs.

These instructions must be always obeyed. Floppy Discs have the different capacities such as MT 720 KBS (kilobyte) and 1.44 (megabyte). Floppy Discs have also different sizes, 3.5' and 5.25'. At the most general used floppy Disc normally is 3.5'. It is not soft and cannot not be bent, where, since a disk is soft 5.25' and can is bent! A floppy Disc is coated a round, flat piece by plastics with ferric oxide, one rustlikesubstanz, which contains the small particles, which are capable of holding a magnetic field, and wrapped in a protecting plastic cover, the disk jacket.

Data are stored on a disk by the read recording head of the drive assembly, which changes the magnetic determining position of the particles. Determining position in a direction represents binary 1; Determining position in the other one, binary 0. The purpose of my experiment was to examine floppy Discs in order to see, as sensitive them close magnets is and how much damage to be taken place can the disks and the software on it tschuess an individual magnet. I hope also that my project helps others, in order to note that computer disks for temperature, weather, magnet are... etc. very sensitive and sensitive.

If the magnets close of the disk are bought, the disk as well as the software in it should be damaged internally. And the weakest magnet should cause few the damage and the strongest magnet should most damage cause. Each disk DOS (4.00.950) has 2874 sectors. This was calculated, by dividing the total number byte on a disk by the number of byte, which occupies each sector. There is a total quantity of 1.457.664 bytes on each floppy Disc, and each sector occupies 512 bytes. Therefore 512/1457664 2874, IE are the total number sectors on each floppy Disc.

First I received four IBM formatted disks 3.5'. First I received the four different magnets of the different strengths and sizes and examined and examined their strengths, by getting iron archivings close everyone of them and observing, how much iron archivings everyone of them tightened and then, noticing, which magnet was the strongest and was which the weakest in the order. Then I examined each of the disks for existing disturbances, by using a program, doctor the Norton disk (NDD) am called that the ability have to determine and regulate disturbance on a disk.

There was no disturbance on any of the four disks. First I decided to hold the magnets near the disks for experimenting for approximately 30 seconds at the approximately same place on the disk. I did in such a way on the whole disk four. Then I got the disks home and examined all four of the disks in a searching disk and repair program called doctor Norton disk. I notes that each of the disks suffered damage. Everyone the disk four was numbered.

The floppy Disc with the weakest magnet was ' disk 1 ' and the floppy Disc with the strongest magnet was ' disk 4 ' and/or. This was done, in order to avoid possible disorder in the disks. Each disk has 2874 sectors. This was calculated, by dividing the total number byte on a disk by the number of byte, which occupies each sector. There is a total quantity of 1.457.664 bytes on each floppy Disc, and each sector occupies 512 bytes.

Therefore 512/1457664 2874, IE are the total number sectors on each floppy Disc. After the examination I that even the smallest of the magnets could cause bad sectors and damage both, discovered the disk and the data concerning the disk. It thought even that the damage was very large, it was largely enough to spoil no program over the disk becuase each part of the present document would be necessary for its correct use and all bad sectors would destroy nearly the document and would form them worthlessly.

This experiment shows that that floppy Discs for magnets are very sensitive and should not not close them at at each time be gotten. When the magnets were gotten near the floppy Discs, the disks were damaged and the weakest magnet caused few the damage and the strongest magnet caused most damage.

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