Bruce Johnson wrote: > > On Jan 27, 2009, at 10:02 PM, Kris Tilford wrote: > >> I'd guess an MRI would ruin and magnetic media also if the media got >> close enough. Interestingly, Rolex manufactures a non-magnetic watch >> for use in high magnetic field industries such as aluminum smelting or >> MRI operator. > > > > Given that MRI systems have hard drives inside of them, and we have > computers within 15 feet of high frequency (and hence high powered > magnets...ours use helium-cooled superconducting magnets) NMR systems > leads me to believe that this wouldn't be so reliable :-) > > On the other hand, these systems are just fine and dandy for > scrambling every.damn.credit.card in your wallet if you forget to > store it outside somewhere. > > That's a VERY embarrassing situation to be in, when you're standing at > the checkout line, trying card after card after card, getting nowhere. > > And no, nope, never happened to me nuh uh! 8-P >
If you have ever taken a close look at the construction of a modern hard drive, you will notice that inside the hard drive itself there are two EXTREMELY POWERFUL small magnets. These function within centimeters of the platters themselves, yet we retain our data. I realize that the magnetic fields in an MRI are orders of magnitude stronger, but the main reason that the DOD an other bodies require multiple erasure and re-writes, is because the data will survive until it has been effectively overwritten. And if it survives, it can be accessed. In my training school I saw an instructor wipe and re-write a hard drive twice, install an OS (Solaris 2.5 to be specific), and was still able to retrieve part of a text file. Ya just can't kill some files. That is why some agencies of the US government are now requiring that their old drives be shredded. But, since a gentleman in NZ just found US Army data on an MP3 player he bought used, it sounds like that rule is being ignored also. Peace, Dennis in Edna, TX --~--~---------~--~----~------------~-------~--~----~ You received this message because you are subscribed Low End Mac's G3-5 List, a group for those using G3, G4, and G5 desktop Macs - with a particular focus on Power Macs. The list FAQ is at http://lowendmac.com/lists/g-list.shtml and our netiquette guide is at http://www.lowendmac.com/lists/netiquette.shtml To post to this group, send email to [email protected] To unsubscribe from this group, send email to [email protected] For more options, visit this group at http://groups.google.com/group/g3-5-list?hl=en Low End Mac RSS feed at feed://lowendmac.com/feed.xml -~----------~----~----~----~------~----~------~--~---
