Shell's "get base (INT 21h, E9h - Novell NetWare 4.6)

        Entry:
          AH = E9h
          AL = subfunction
            00h get directory handle
          DX = drive number to check (0 = A:)
        Return:
          AL = network pathbase
          AH = base flags
            00h  Drive not currently mapped to a base
            01h  Drive is mapped to a permanent base
            02h  Drive is mapped to a temporary base
            03h  Drive exists locally