                                RTS 1.2
            A program to toggle the RTS line in RBBS doors
                                  by
                               Bob Eyer
                            April 27, 1990

     Syntax:
     RTS [port]

     where  port  may  be either 1 or 2.  If port is not entered on the
     commandline, or if any number other than 1 or 2  is  entered,  RTS
     defaults port to 1.

     This  program  toggles  the  logic status of the RTS line, without
     altering the DTR  line,  and  deals  directly  with  standard  IBM
     hardware modem control registers for ports 1 or 2.   It  does  not
     open  or  close the communications port.  RTS 1.2 may executed any
     number  of times without sending invalid data to the modem control
     register, and will not stay resident in memory.  Consequently, use
     of this program  does  not  reduce  free  space  available  for  a
     specific door program.

     If RTS is low, this program will set it high; if high it will  set
     the  level  to low.  RTS 1.2 will not provide any video output, as
     it  is designed to be invoked from a batch file which controls the
     processing of a specific door program - so that the remote user is
     not aware of its operation.  Therefore, the Sysop  must  use  some
     other  indicator program to determine the actual status of the RTS
     line, such as RS232.COM - or the RS light on the host modem.

     General Discussion:
     ------------------
     Have  you  found a door program which, when accessed through shell
     or exit doors of RBBS, simply hangs remote video?  This may be the
     program which solves your problem.

     Most  door  programs  don't  have  RTS/CTS  problems when executed
     through the shell or exit routines of RBBS.  This is  due  to  the
     fact that most door programs, particularly those which are written
     in  BASIC, will reopen the communications port in such a way as to
     raise the RTS line.

     However, when RBBS or other  communications  programs  written  in
     Microsoft  BASIC  drop  to  DOS  either  by use of the shell or by
     exiting code, they will set the RTS line to logic low, even  where
     the  BASIC compiler used for generating the executable program has
     been revised to keep DTR at logic high.

     Setting the RTS line at logic low means that programs which reopen
     the communications port without correcting this problem  will  not
     send any information.  Typically, such programs will be written in
     a  language, such as Pascal or C, which don't make any assumptions
     about how the port should be opened; and some authors forget  that
     not  all  host  programs allow doors to pick the RTS logic off the
     host's settings.

     RTS  1.2  should solve this problem.  However, don't use it unless
     you're sure you have an RTS logic problem: If  your  host  program
     keeps RTS high after drop to DOS, using RTS 1.2 will force it low.

