Stupid question on hard drives and magnets

Arclight · 06-10-09, 08:59 AM

The magnetic field caused by the parts doesn't change, ie it's constant.

If data is written while under the influence of this field, it will remain the way it's written since the field doesn't vary. By introducing another magnet, the field changes/is disturbed, and that's what influences the data layer, effectively altering/destroying the data contained on it.

Think of a compass: the Earth has a magnetic field, and the needle always points north because the field is constant. If you hold a magnet next to the compass, the needle changes orientation.

Think of the needle as the data: as long as it points north, it is correct, even though under the influence of a magnetic field (the internal HD parts). Changing the field (moving a magnet across the HD) puts the needle in an "incorrect" position (data is destroyed).

06-10-09, 08:59 AM	#4
Arclight Navy Seal Join Date: Jun 2008 Location: Land of windmills, tulips, wooden shoes and cheese. Lots of cheese. Posts: 8,467 Downloads: 53 Uploads: 10	The magnetic field caused by the parts doesn't change, ie it's constant. If data is written while under the influence of this field, it will remain the way it's written since the field doesn't vary. By introducing another magnet, the field changes/is disturbed, and that's what influences the data layer, effectively altering/destroying the data contained on it. Think of a compass: the Earth has a magnetic field, and the needle always points north because the field is constant. If you hold a magnet next to the compass, the needle changes orientation. Think of the needle as the data: as long as it points north, it is correct, even though under the influence of a magnetic field (the internal HD parts). Changing the field (moving a magnet across the HD) puts the needle in an "incorrect" position (data is destroyed). __________________ Contritium praecedit superbia.