INT 2fH 4a11H BX=0002H: Dblspace Swap Drive

                                                         Compatibility: 6.0+ 
 Expects: AX    4a11H (mux number)
          BX    0002H (DoubleSpace fn code)
          DL    compressed drive number to swap with its host
 Returns: AX    DoubleSpace API Error Code (0000H=success)
    Info: This swaps a DoubleSpace compressed drive's ID with the ID of its
          host drive.

          For instance, if drive C contains a CVF named DBLSPACE.000, then
          when DoubleSpace starts up, it will mount that CVF as drive J
          (for example).

          To set up so the compressed volume is drive C (and set the host
          as drive J), you would set DL to 9 (0=A, 1=B,...9=J)

   Notes: ■ There is no "unswap" variation of this fn; if you attempt to
            swap a previously-swapped drive, this fn returns an error.

          ■ DBLSPACE.BIN performs disk swapping automatically, based on
            settings in DBLSPACE.INI.  I recommend against using this fn.

See Also: DoubleSpace Overview
          DoubleSpace API
          INT 2fH: Multiplex Interrupt
          DOS Functions