Synchronet v3.19b-Win32 (install) has been released (Jan-2022).

You can donate to the Synchronet project using PayPal.



CIOXTRN is a program in the spirit of the old DoorWay program. It takes the screen output of a console program and sends it as ANSI to stdout and reads keystrokes from stdin which are sent to the program.

The main difference between CIOXTRN and DoorWay is that CIOXTRN is a Windows program and supports Win32 consoles in addition to 16-bit programs running in a windows console.


To run a program under cioxtrn, simply pass the command line. For example:

cioxtrn c:\windows\system32\cmd.exe

Example configuration for Windows cmd.exe in SCFG->External Programs->Online Programs1):

║                            CMD                           ║
║ │Name                       CMD                          ║
║ │Internal Code              CMD                          ║
║ │Start-up Directory                                      ║
║ │Command Line               %!cioxtrn.exe cmd.exe        ║
║ │Clean-up Command Line                                   ║
║ │Execution Cost             None                         ║
║ │Access Requirements                                     ║
║ │Execution Requirements                                  ║
║ │Multiple Concurrent Users  Yes                          ║
║ │I/O Method                 Standard, No Echo            ║
║ │Native Executable/Script   Yes                          ║
║ │Use Shell or New Context   No                           ║
║ │Modify User Data           No                           ║
║ │Execute on Event           No                           ║
║ │Pause After Execution      No                           ║
║ │Disable Local Display      No                           ║
║ │BBS Drop File Type         None                         ║


When CIOXTRN starts up, it changes the console screen size in an attempt to match the remote users. The screen height is automatically detected if possible or assumed to be 24 rows and the screen width is always assumed to be 80 columns.

If something resizes the console window, it may still be usable. CIOXTRN allows control of this via two mechanisms.

1) -t and -b specified before the command.
	This forces cioxtrn to display the top (-t) or bottom (-b)
	of the screen.  For cmd.exe, -b would be best and for,
	-t (the default) would be best.
2) CTRL-Z will toggle between the top and bottom display modes while
	using cioxtrn.
	cioxtrn -b C:\windows\system32\cmd.exe
	cioxtrn -t C:\windows\system32\

Extra key bindings

CIOXTRN enables and uses doorway if the remote system supports it. It will also accept three extra keystrokes which do CIOXTRN specific things. The FIRST time they are pressed, they only do the CIOXTRN defined function and are not passed to the remote. Subsequent presses behave differently for each key as described below:

CTRL-A: Depresses and holds down the ALT key until the next keystroke.
	if the next keystroke is a CTRL-A, only CTRL-A is sent to the
	program, not CTRL-ALT-A.  As a result of this behaviour, there
	is no way to send CTRL-ALT-A.
CTRL-R: On the first entry, forces a screen redraw.  Subsequent CTRL-R
	keystrokes without other intervening chars will be sent to the
CTRL-Z: Toggles between displaying the top of the console buffer or the
	bottom.  This key ALWAYS toggles the display, but is also sent
	to the remote after the first press.

See Also

i.e. for a better remote Windows shell experience