🚀 go-pugleaf

evans1@cbnewsm.cb.att.com (Dan Evans) writes:
>jeric@berkp.uadv.uci.edu (Jeric Woo) writes:
>>I have some high density 3.5" and 5.25" diskettes that I would like to
>>use as low density diskettes.  However, whenever I attempt to format them
>>(using low density drives) I get either the messages "Bad or Invalid Media"
>>or the message "Track 0 Bad, Disk Unusable."

>The LD drive heads are larger then the HD heads.  As a result the LD heads
>are reading more then one track at a time on the HD disk. Track 0 isn't
>bad, it's just smaller then the LD drive is capible of reading it.

    There's an additional purely mechanical problem with using 5 1/4" HD 
disks in DD drives. DD 5 1/4" disks have a reinforcing "hub ring" that 
provides a thicker handle for DD drives to grab onto. HD disks do not 
have such a ring, so when you stick your HD disk in that DD drive there's 
a strong possibility that the disk won't be seated in the exact same 
alignment that it was when the data was originally written. Repeatedly 
removing and reinserting the disk will get you there eventually, but it's 
a bad idea as far as long term storage is concerned. If you're doing this 
to be able to exchange data with PCs that only have 360K drives then 
get yourself a bunch of real 360K floppies. You might even want to install 
a real 360K drive in a "media translation" machine so that you can write 
your 360K disks in a way that practically guarantees no hitches.

--
Nathan Engle                        Software Juggler
Psychology Department               Indiana University
nate@psygate.psych.indiana.edu      nengle@copper.ucs.indiana.edu