Source : Free On-Line Dictionary of Computing

Mini Disc
     
         A music medium designed by {Sony} as a
        portable replacement for music {Compact Discs}.  In 1994 Sony
        announced a data version which can hold 140 MB or about 100 MB
        using {error correction}.  These will be competitive with 128
        MB {magneto-optical} disks.  Mini Discs may be either a
        re-writable or mass-produced read-only type.  Sony have also
        announced a standard data format.
     
        The transfer rate is similar to {CD-ROM} which is slow
        compared to the current {magneto-optical} drives (which are
        similar to an old hard disk, with writing noticeably slower
        than reading).  Pre-recorded read-only Mini Discs can be mass
        manufactured on a modified CD press - this and the standard
        format mean it could take off as a software distribution
        medium.
     
        An article in the December 1994 PCW quotes {access time}s of
        about 300 ms and data transfer rate of about 150 kb/s (i.e.
        about single spin CD rate).
     
        (1994-12-13)