[tavilach]

What exactly do magnets do to hard disks? The magnetic mount of my iSight came very close to the palm rest of my PowerBook, for a second. I'm assuming that this is fine?

[milkmanchris]

Originally posted by tavilach:
What exactly do magnets do to hard disks? The magnetic mount of my iSight came very close to the palm rest of my PowerBook, for a second. I'm assuming that this is fine?

Here are two websites where you can get some explanation:

http://www.hardwarecentral.com/hardw...utorials/41/2/
http://www.ntfs.com/hard-disk-basics.htm

Magnets can affect the info in a hard drive because it is written magnetically just like old music tapes.
They have anr "arm" ended in a head that turns the small magnetic particles in two ways so they mean zero or one depending on where they point

Hope this helps, what were u doing with the iSight aiming so low ????

[tavilach]

Originally posted by milkmanchris:
Here are two websites where you can get some explanation:

http://www.hardwarecentral.com/hardw...utorials/41/2/
http://www.ntfs.com/hard-disk-basics.htm

Magnets can affect the info in a hard drive because it is written magnetically just like old music tapes.
They have anr "arm" ended in a head that turns the small magnetic particles in two ways so they mean zero or one depending on where they point

Hope this helps, what were u doing with the iSight aiming so low ????

Can it affect the hard drive permanently, or just the information on it?

I was installing my iSight, looking at the different mounts. I looked at the magnetic mount close to the palm rest.

Would this really have done anything for a second, considering that there is aluminum in between and all?

[milkmanchris]

Originally posted by tavilach:
Can it affect the hard drive permanently, or just the information on it?

I was installing my iSight, looking at the different mounts. I looked at the magnetic mount close to the palm rest.

Would this really have done anything for a second, considering that there is aluminum in between and all?

Here are two websites where you can get some explanation:
http://www.hardwarecentral.com/hardw...utorials/41/2/
http://www.ntfs.com/hard-disk-basics.htm

[tavilach]

Originally posted by milkmanchris:
Here are two websites where you can get some explanation:
http://www.hardwarecentral.com/hardw...utorials/41/2/
http://www.ntfs.com/hard-disk-basics.htm

Right, my bad. I shall read.

[macaddict0001]

it should be fine if you haven't noticed any problems after a while of using your computer.

[alligator]

I put a magnetic screwdriver on top of a hard drive once (PC). Nothing happened at all. I thought for sure it might mess it up - but I guess these are more resistant to stray magnetic fields than we thought.

[unimaxium]

Originally posted by tavilach:
Can it affect the hard drive permanently, or just the information on it?

I was installing my iSight, looking at the different mounts. I looked at the magnetic mount close to the palm rest.

Would this really have done anything for a second, considering that there is aluminum in between and all?

I doubt the isight mount could do very much damage if it was only there for a short while. But just FYI the aluminum would not make a difference if the mount were strong enough to actually damage the HD. If you were to put the mount directly on the hard drive (i.e. actually open the case and put the magnet on the HD casing) it would be possible to do damage, depending on how strong the magnet is. Also, if the magnet in the mount strong enough there is always a chance that it could (or did) damage the harddrive, possibly permanently. But with an iSight mount I would call it quite doubtful. I do not know how strong of a magnet is in that mount, but my guess is that it is not enough to damage the HD from the distance of the wrist pad.

This actually makes me wonder... does anyone know if hard drives these days are actually shielded in any way from magnets outside the casing? I thought they use pretty strong magnets inside the actual drive (I once saw a really powerful magnet that someone told me came out of an HD. He used it to magnetize his screwdrivers to make it easier to, um, screw... stuff.). If they put such powerful magnets inside the actual casing then either they must have some way to shield the magnet from the platters or the platters must not be very vulnerable to magnets after all.

[tavilach]

Originally posted by unimaxium:
I doubt the isight mount could do very much damage if it was only there for a short while. But just FYI the aluminum would not make a difference if the mount were strong enough to actually damage the HD. If you were to put the mount directly on the hard drive (i.e. actually open the case and put the magnet on the HD casing) it would be possible to do damage, depending on how strong the magnet is. Also, if the magnet in the mount strong enough there is always a chance that it could (or did) damage the harddrive, possibly permanently. But with an iSight mount I would call it quite doubtful. I do not know how strong of a magnet is in that mount, but my guess is that it is not enough to damage the HD from the distance of the wrist pad.

This actually makes me wonder... does anyone know if hard drives these days are actually shielded in any way from magnets outside the casing? I thought they use pretty strong magnets inside the actual drive (I once saw a really powerful magnet that someone told me came out of an HD. He used it to magnetize his screwdrivers to make it easier to, um, screw... stuff.). If they put such powerful magnets inside the actual casing then either they must have some way to shield the magnet from the platters or the platters must not be very vulnerable to magnets after all.

So far, I haven't noticed any difference in performance. This means that nothing happened at all, correct?

The iSight mount magnet is about half a centimeter or a centimeter thick (the rest is plastic), and the diameter of, say, a nickel. I felt it attracting my plastic (with lots of metal inside, of course) dell flat planel when it came within a centimeter or two. On the other hand, it was a few inches away from the palm rest of my PowerBook.

My PowerBook has gone through Airport Security...those are strong magnets! If that was fine, and it should be...then I don't see why this wouldn't be. There must be some sort of shielding, as no one reports this a problem (with PowerBooks), typically.

Plus, on the iSight mount warning, it says not to place near CRT's, iPods, or external hard disks...but no mention of internal hard disks! That must mean it's okay.

Perhaps if I placed it on my PB for an extended period of time...

[macaddict0001]

nahh no harm done but you said performance while it might slow the computer down if it was trying to decipher corupted data it is more likely you would recieve a dialog that say's something like the file you are trying to access is corrupted.

[tavilach]

Originally posted by macaddict0001:
nahh no harm done but you said performance while it might slow the computer down if it was trying to decipher corupted data it is more likely you would recieve a dialog that say's something like the file you are trying to access is corrupted.

Good point .

[d4nth3m4n]

would the isight magnet even work on a pb?

[tavilach]

Originally posted by d4nth3m4n:
would the isight magnet even work on a pb?

If it works on my plastic Dell FP, I'm sure it would . It would kill it, too.

Edit: It wouldn't be able to balance on the top of the PB, though...

[AlbertWu]

ever seen the inside of a hard drive?

there's a huge-ass electromagnet that moves the head back and forth. you'd need a really big bulk-eraser magnet to do any damage. don't sweat it.

[unimaxium]

Originally posted by AlbertWu:
ever seen the inside of a hard drive?

there's a huge-ass electromagnet that moves the head back and forth. you'd need a really big bulk-eraser magnet to do any damage. don't sweat it.

That's what I thought. That magnet is really powerful too.
For anyone who's interested, I've posted a detailed explanation on how files are stored on a harddrive over at spymac:
http://www.spymac.com/gallery/show_p...hp?picid=41886