RTS 2.0
A program to toggle the RTS line in doors
by
Bob Eyer
[73230,2620]
Nov 4, 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 2.0 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 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, some host programs may, under certain conditions, lower
the RTS line when dropping to DOS for a door application, even
where DTR is unaffected.
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 2.0 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 2.0 will force it low.
DISCLAIMER:
==========
This program is circulated as public domain without any guarantee
or warranty; and the user, by downloading this program, or any
variant thereof or by receiving it or any of its versions in any
other form, agrees to accept full responsibility for its use. It
is therefore understood that the user accepts this program or any
previous version as is.
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End of documentation.