3 Oct
2011
3 Oct
'11
12:35 p.m.
I have found that floppies are sensitive to the stray
fields
of things like monitor deflection coils while they are being recoded.
I've never seen similar fields cause any problem while reading.
Even moving the monitor as little as another 6 inches was enough
to stop the problem.
I am supriset it affected writing and not reading. Had it been the other
way round, I would have suspected interfecent pickup in the read
amplifier (seen that often enough), this does not damage the disk though.
I assume your disks written when the drive was too close to the monitor
were not readable elsewhere, the data on the disk was genuinely
corrupted. But I don;t see why a disk would be more susceptable to
external mangetic fields when writing than at any other time.
It also may not have been the defleciton coils. There are plenty of other
magnetic devices in CRT nonitors -- PSU transformer, flyback transformer,
degausisng coil (if a colour CRT), etc.
-tony