26 Mar
2000
26 Mar
'00
9:36 a.m.
This is only part of the story
The 1.2 Mb floppies are written with a lower write current than the
360 Kb. Since the magnetic quality of the former type is stronger and the
tracks are smaller and closer this will prevent crossover effects between
the tracks.
In certain situations it may be desirable to attempt a datatransfer
between different drive systems. Then a repeated formatting of
a bulkereased or brandnew unformatted 360Kb floppy written with a
1.2 Drive may do the trick. You will also have to write the data
repeatedly. This may only work over hours or days rather than month or
years.
Sipke de Wal
----- Original Message -----
From: Fred Cisin (XenoSoft) <cisin(a)xenosoft.com>
To: <classiccmp(a)classiccmp.org>
Sent: Sunday, March 26, 2000 10:16 PM
Subject: 360K in a 1.2M drive (was: Parallel port hard drives?
> It doesn't matter whether the diskette is a
1.2 MB one or a 360K type,
but
Give us a break! YOU know better!
YES, IT WILL MATTER!
And it is NOT necessary for any idiot to say, "But I use the wrong type of
diskettes all the time."
360K is 300 Oerstedt. 1.2M is 600 Oerstedt.
My personal experience is that using a 600 Eorstedt diskette in a 300
Oerstedt application results in a significantly reduced lifetime for the
data. Sometimes minutes!
> the drive which wrote it make a great deal of difference. 1.2 MB drives
can
> read 360k diskettes just fine, but you can't
expect a drive designed to
> operate on half the track width (twice the density) and even more bit
> density, to erase the writing of a 48 TPI 360K drive properly. It works
OK
> the first time, and less well the second ... and
so on until it fails
> because the residue left behind by the 48tpi drive generates too much
noise
for the 96 tpi
drive to discriminate between noise and signal.
If you HAVE to use a 1.2M drive to write 360K diskettes, it is best to
start with a virgin disk. And ALWAYS bulk erase it (preferably with a
better bulk eraser than the one on your refrigerator door). THEN format
it as 360K ("/4" in DOS). If the diskette is EVER written to by a 360K
drive (even "ERASE"ing a file), then bulk erase and FORMAT in the 1.2M
drive again.
You have to take these steps if you want reliable writes to 360K in a 1.2M
drive, even if you might sometimes get away with not doing it right.
--
Grumpy Ol' Fred cisin(a)xenosoft.com