slc@hoptoad.uucp (Steve Costa) (06/18/89)
I noticed that various devices on my desktop put out magnetic fields to one degree or another. The strongest come from the small speakers attached to a little stereo amp that is attached to my 2000. However the monitor, DeskJet printer, and telephone also produce fields. A month or so ago, a floppy that I had left sitting near one of the speakers had some problems. I was able to retrieve the files on it with DiskSalv. Is it likely that the field from the speaker did this, or would magnetic disruption have been so random as to make the data irretrievable? In general, it would seem that disks can tolerate mild magnetic fields, because, using a compass, I detected a field in the vicinity of my hard drive. I'm concerned about whether it's safe to leave a few floppies sitting around on top of the desk, near the printer or phone (but staying away from those speakers).
fc@lexicon.com (Frank Cunningham) (06/20/89)
In article <7696@hoptoad.uucp> slc@hoptoad.uucp (Steve Costa) writes: > A month or so ago, a floppy that I had left sitting near one of the > speakers had some problems. I was able to retrieve the files on it > with DiskSalv. Is it likely that the field from the speaker did this, > or would magnetic disruption have been so random as to make the data > irretrievable? The field to worry about from a loudspeaker is DC, the audio stuff is noise by comparison (depending on what you listen to :-) ). It is very likely the speakers did it, and the longer you left the disk there, the less you would have retrieved. > In general, it would seem that disks can tolerate mild magnetic > fields, because, using a compass, I detected a field in the vicinity > of my hard drive. I'm concerned about whether it's safe to leave a few > floppies sitting around on top of the desk, near the printer or phone > (but staying away from those speakers). I don't think the hard-drive generates a dangerous field, for the obvious reason. If it has a ferro-magnetic frame, the frame may be magnetized by the earth's field, or by proximity to those speakers. Don't leave stuff near the phone; the earpiece is a small dynamic speaker, and the traditional bell ringer has some big magnets. -- -Frank Cunningham smart: fc@lexicon.com dumb: {husc6,linus,harvard,bbn}!spdcc!lexicon!fc phone: (617) 891-6790