21 Feb
2008
21 Feb
'08
11:31 p.m.
On 21 Feb 2008 at 21:43, dwight elvey wrote:
Some of the newer hard disk heads use a head that
doesn't require
a speeding head to read. It is like a hall effect in that it measure total
magnetic field. It isn't like a hall effect in that it snaps from one state to
another. The advantage is that it isn't speed sensitive, just level.
I forget what this type is called. One could raise and lower it along
the track, never scrapping the surface, just sampling. One would turn
a 1/4 bit at time and sample that location. One would then record any
pulse, indicating a flux reversal.
Er, GMR? http://en.wikipedia.org/wiki/Giant_magnetoresistance
not to be confused with the superlatively exciting Colossal
Magnetoresistance.
Cheers,
Chuck
(wonder what's bigger than "Colossal"?)