Set logical drive (INT 21h, 440Fh)

        This function can be used, to set the last drive used for a
        device. Use this function together with INT 21h, 440Eh (see
        example there).

        Entry:
          AX = 440Fh
          BL = Drive
        Return:
          AL = 0, if device don't have more than one drive letter assigned.
               Otherwise, this call sets that the current logical drive
               letter for this device, is in BL (and should be in AL
               afterwards ...).