3 Jun
2012
3 Jun
'12
4:48 p.m.
On Sun, 3 Jun 2012, David Griffith wrote:
I'm pondering putting 3.5" and 5.25"
floppy drives in a single chassis
along with a Discferret / Kryoflux. The 3.5" can be HD with no problem.
I'm leery of the complications of DD versus HD 5.25" drives. If I
bulk-erase a DD disk and write to it with an HD drive, might there be any
problems when the disk is used again on a DD drive?
That will usually be OK
Would simply formatting the DD disk be enough?
NO.
Formatting or re-writing a DD track with an HD drive will not adequately
wipe the sides of the track enough for reading with a DD drive. Although it
may look and work fine, if you never try to read it with anything but an
HD drive.
A DD track is about 1/3mm wide, and spaced about 1/2mm apart (48 tpi)
An HD track is about 1/6mm wide, and spaced about 1/4mm apart (96tpi)
The ENTIRE problem is that the 1/6mm wide head can NOT completely erase
the 1/3mm wide track, although it can do so enough that IT doesn't mind
the margins left behind.
Bulk erasing and formatting and writing a "360K"/DD with an HD drive will
give tracks that are 1/6mm wide spaced 1/2mm apart, and everybody is at
least OK with reading that.
For primarily reading, an HD drive will handle most of what you need, and
the rarer instances of writing can be dealt with by bulk erasing first.
If you're going to also mess with weird crap like 100tpi and 192 tpi, then
you need a large collection of alternative drives to swap in and out.
--
Grumpy Ol' Fred cisin at xenosoft.com