21 May
2003
21 May
'03
5:53 a.m.
"360K" diskettes are 300 Oersted. That is a measurement of magnetic
coercivity. If you have no idea what that means, think of it as being
like film speed in photography.
"1.2M" diskettes are 600 Oersted. That is way too different from 300
Oersted for interchange to work in either direction with
"360K" diskettes.
"720K" 3.5" diskettes are 600 Oersted.
"1.4M" 3.5" diskettes are about 750 Oersted.
600 and 750 are close enough that you can almost get away with it. You
can turn a good diskette of one into a crummy diskette of the other.
What part of that is hard to understand?
I especially liked the old ads for the punches, particularly the ad where
the guy could "PROVE" that the diskettes were the same, because he had
measured them with a micrometer.
In many of the cases, the disk is usually hosed after
this and won't take
a format back to HD anymore.
Fortunately, there is no damage that formatting can do
that can't be
undone by bulk erasing.