stiffy

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

stiffy
firmy

   <storage, jargon> ({University of Lowell}, Massachusetts) A
   3.5-inch {microfloppy}, so called because their jackets are
   more rigid than those of the 5.25-inch and the (obsolete)
   8-inch {floppy disk}.  Elsewhere this might be called a
   "firmy".

   [{Jargon File}]

   (1994-11-03)