[Simh] How to detect telnet disconnection.

[Mark Pizzolato - Info Comm]

On Saturday, June 20, 2015 at 5:48 PM, Harry Reed wrote:
> We am currently in the process of implementing a simh based emulator for
> the Multics CPU (https://sourceforge.net/projects/dps8m/). We've got it
> set up so we can telnet into the OS using the SIMH "Telnet terminal
> multiplexer library," but are having problems when connections are lost
> not freeing up lines, etc. I need to be able to detect when a telnet
> connection is dropped, not closed normally.
> 
> Any thoughts on how to detect a dropped telnet connection?

Well, detecting connection drops is certainly possible.  Numerous other devices which use the "Telnet terminal multiplexer library" do this.

There is a significant body of code at https://sourceforge.net/projects/dps8m/ which is organized in a reasonably complicated way.  I unpacked the dps8.tar.gz tarball, but it isn't immediately obvious which module implements the multiplexer device.  Please point me at the module which uses the sim_tmxr library and I'll suggest ways you can detect/manage dropped telnet connections.

- Mark