dongle-disk

from Jargon File (4.4.4, 14 Aug 2003)

dongle-disk
 /don'gl disk/, n.

   A special floppy disk that is required in order to perform some task.
   Some contain special coding that allows an application to identify it
   uniquely, others are special code that does something that
   normally-resident programs don't or can't. (For example, AT&T's "Unix
   PC" would only come up in {root mode} with a special boot disk.) Also
   called a key disk. See {dongle}.

from The Free On-line Dictionary of Computing (8 July 2008)

dongle-disk

   /don'gl disk/ (Or "key disk") A kind of {dongle} consisting of
   a special {floppy disk} that is required in order to perform
   some task.  Some contain special coding that allows an
   application to identify it uniquely, others *are* special code
   that does something that normally-resident programs don't or
   can't.

   For example, {AT&T}'s "Unix PC" would only come up in {root
   mode} with a special boot disk.

   [{Jargon File}]

   (1998-12-13)