Connection id (INT 21h, F0h - Novell Advanced NetWare 1.0+)

        Entry:
          AH = F0h
          AL = subfunction
                  00h  Set preferred connection ID
                  01h  Get preferred connection ID
                  02h  Get default connection ID
                  03h  LPT capture active
                  04h  Set primary connection ID
                  05h  Get primary connection ID
          DL = preferred file server
        Return:
          AL = selected file server