On Tue, Aug 18, 2015 at 1:45 PM, Fred Cisin <cisin at xenosoft.com> wrote:
  On Mon, 17 Aug 2015, drlegendre . wrote:
  Terry & all,
 To be clear - SD on a "360K" floppy is 180K? Yes?
 
 NO.
 Osborne SD was also single sided.
 10 256 byte sectors per track.  100K.
 "360K" was 9 512 byte sectors, with TWO sides used. 
Hmm.  I don't have the machine in front of me to check (I'm at work), but I
pretty sure my Osborne 1A drives are single sided not double sided.  But I
have the double density modification so yes, around 180-200k per disk I
imagine.   Using the PC and Imagedisk I could easy write DD single-sided
disks in a double sided (360k PC) drive though.
Terry (Tez)