22 Mar
2010
22 Mar
'10
10:39 p.m.
On Monday (03/22/2010 at 05:54PM -0700), Fred Cisin wrote:
On 22/03/2010 19:18, Alex Taylor wrote:
So, does that mean that the 720K (600 Oersted) media requires a bigger
signal (ie, more write current) than the 750 Oersted 1.44M or the other
way around? It would seem that in one case you would be overdriving
the media and in the other case you might be underdriving it. Which way
is which?
Chris
--
Chris Elmquist
The idea was that reformatting a 1.44MB HD disk
in a DD drive will
leave traces of the original formatting behind (as they're always
preformatted for DOS/Windows), causing the unreliability. Using a bulk
eraser is meant to eliminate this problem, as it will turn them into
completely blank disks that can be formatted in a DD drive more
reliably.
In addition to all that, . . .
The coercivity (sorta like magnetic sensitivity) is WRONG.
"720K" diskettes are 600 Oersted.
"1.4M" diskettes are about 750 Oersted.
It IS close (unlike 360K (300 Oersted) v 1.2M (600 Oersted)), and it WILL
work (unlike 360K v 1.2M), but it will NOT be as reliable as using the
correct diskette.