Реферат: How Magnets Affect Computer Disks Essay Research

How Magnets Affect Computer Disks Essay, Research Paper

How Magnets Affect Computer Disks

BackGround

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

time,

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

another.

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

data,

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.

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.

Purpose

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.

Hypothesis

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.

Experimentation

Material:

Four 3.5″ Floppy Diskettes.

Four different Magnets

One Personal Home Computer

Printer

Software:

Windows95

Norton Disk Doctor

Dos (Ver 4.00.950)

Procedure:

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 (Highland?

). 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

experimentation for about 30 seconds at about the same place on the disk. I did

so on all of the four disk.

Then, I brought the disks home and tested all four of the disks in a

disk testing and repair program called Norton Disk Doctor. I notices that each

one of the disks suffered damage.

Every one of the four disk was numbered. The Floppy with the weakest

magnet was “Disk 1″ and the Floppy with the strongest magnet was “Disk 4″

respectively. This was done to avoid possible confusion in the disks.

Result

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.

After every Floppy had been tested, I noted all the results. The results

were as follows:

Disk 1:

Total Bytes on Disk: 1,457,664 Total Bytes in Bad Sectors: 3584 Total Number

of Sectors: 2874 Total Number of Bad Sectors: 7 Total Number of Good Sectors:

2867

Disk 2:

Total Bytes on Disk: 1,457,664 Total Bytes in Bad Sectors: 5632 Total Number

of Sectors: 2874 Total Number of Bad Sectors: 11 Total Number of Good Sectors:

2863

Disk 3:

Total Bytes on Disk: 1,457,664 Total Bytes in Bad Sectors: 15360 Total Number

of Sectors: 2874 Total Number of Bad Sectors: 30 Total Number of Good Sectors:

2844

Disk 4:

Total Bytes on Disk: 1,457,664 Total Bytes in Bad Sectors: 19968 Total Number

of Sectors: 2874 Total Number of Bad Sectors: 39 Total Number of Good

Sectors: 2833

After the testing, I discovered that even the smallest of the Magnets

could cause bad sectors and damage both, the disk and the data on the disk. Even

thought the damage wasn’t very big, it was big enough to corrupt any program on

the disk, becuase every part of the present file would be necessary for its

correct use and any bad sectors would almost destroy the file and make it

worthless.

Conclusion:

In conclusion,this experiment proved that floppies are very sensitive

to magnets and should not be brought near them at anytime. When the magnets were

brought near the floppies, the disks were damaged and the weakest magnet caused

the least damage and the strongest magnet caused the most damage.

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