Source : Free On-Line Dictionary of Computing

flippy
     
         /flip'ee/ A single-sided {floppy disk} altered for
        double-sided use by addition of a second write-notch, so
        called because it must be flipped over for the second side
        (the "flip side") to be accessible.  Used in the {Commodore
        1541} and elsewhere.  No longer common.
     
        [{Jargon File}]
     
        (2000-03-07)