0:490h                   Diskette Drive 0 Media State

 Length: 1 byte

    This byte is reserved for the PC, PCjr, PC XT dated 11/8/82, and the
    PC Convertible. For all others, this byte contains the state of the
    floppy diskette drive 0.

                        Diskette Drive Media State

             7 6 5 4 3 2 1 0
             x x . . . . . .      Diskette Drive Data Rate (See below)
             . . x . . . . .      Double Stepping Needed
             . . . x . . . .      Media known
             . . . . x . . .      Reserved
             . . . . . x x x      Media/Drive Types (See below)


                   Diskette Drive Data Rate (Bits 7 and 6)

                         00        500K per second
                         01        300K per second
                         10        250K per second
                         11        Reserved


                    Media/Drive Types (Bits 2, 1, and 0)

                      000       360K/360K not established
                      001       360K/1.2M not established
                      010       1.2M/1.2M not established
                      011       360K/360K established
                      100       360K/1.2M established
                      101       1.2M/1.2M established
                      110       Reserved
                      111       None of the above