Get volume statistics (INT 21h, DAh - Novell NetWare 4.0)

        Entry:
          AH = DAh
          DL = volume number
          ES:DI -> reply buffer
        Return:
          AL = 00h
            reply buffer
                WORD  sectors/block
                WORD  total blocks
                WORD  unused blocks
                WORD  total directory entries
                WORD  unused directory entries
             16 BYTEs volume name, null padded
                WORD  removable flag, 0 = not removable