At 03:31 PM 9/2/2002 -0700, you wrote:
 Did anybody ever market a floppy disk system that
communicated via
RS-232? 
Sure, a number of applications used them.  The Tandy Model 100
early laptop had one.  I've seen others that were used to record
and play back streams coming from 300-baud-era modems, too.
- John