Re: HD 5.25 format?

[rubywand@aol.com]

In article <12DEC199618580250@vax2.concordia.ca>, spec@vax2.concordia.ca
(Mitchell Spector) writes:

>....
>    In comparison, a High Density 3.5" diskette can and will format in a
>single/double density 3.5 drive (eg, standard Macintosh Plus, Apple IIgs,

>Amiga 500, Atari ST, IBM AT/286's). The magnetic coating doesn't seem to
>differ in that sense,  although the _quality_ of the disk surface or that

>coating may.

     The magnetic properties of 3.5" HD and DD surfaces are very different
(just as they are for 5.25" HD and DD diskettes).  Good quality HD
diskettes should be used on HD drives. Using HD diskettes on GS 800k
drives risks the premature loss of data.


>It is not recommended you do this (or visa-versa, by punching
>a notch to make a double density 3.5 function as HD) but this is
debatable.

     It is true that PC users used to punch (drill, etc.)  HD notches in
3.5" DD diskettes and that the DD diskettes would, more often than not,
format to 1.44MB and work fine. With 3.5" HD diskettes selling for less
than $0.03 each, this trick is no longer very useful.  


>Rumour has it that double-density 3.5 diskettes, are merely HD disks that
>did not pass high quality testing (in otherwords, decent enough where it
>will be reliable holding more sectors per track). This would explain the
>HD notch imprint might you find on some double-density 3.5 floppies. :)
>

     In olden times, maybe. Today, HD and DD diskette surfaces use
significantly different formulations.  



Rubywand