Partial success (SIMH TSS/8), new problem has me stumped

Charles charlesmorris800 at
Sat Sep 14 22:40:58 CDT 2019

I finally managed to get TSS/8 running under SIMH V4... console on the 
laptop, a time-sharing line (TTIX port 23) on an ADM-3A (much quieter while 
debugging) :)
The interface is the Volpe current-loop to USB board, a small freeware 
program "COM By TCP" to allow a TCP port (USB is COM4, TCP is port 

So far so good. But I am having connection problems with the data coming 
from SIMH to the terminal.
At 110 baud I only get a few characters before the serial-TCP program hangs 
with this write-timeout message:

22:24:11:   Socket connected to
22:24:11:   SOCK: Unable to write on COM. The port is CLOSED.. <-- this is 
because I didn't "Get COM" first.
22:24:13:   COM4 correctly opened!
22:24:24:   System.TimeoutException: The write timed out.
   at System.IO.Ports.SerialStream.Write(Byte[] array, Int32 offset, Int32 
count, Int32 timeout)
   at System.IO.Ports.SerialPort.Write(Byte[] buffer, Int32 offset, Int32 
   at COMbyTCP.Form.sockClient_dataRecived(Byte[] buffer, Int32 

I tried at 1200 baud and the same problem occurs, I can just get more 
characters before the terminal screen freezes.
Nothing's locked up except the downstream SIMH data (i.e. I can hit Return 
on the terminal and the TSS/8 dot prompt reappears).
It is repeatable regardless of what I am trying to do on the terminal. Only 
very small outputs come through in their entirety without this error 
I don't think it's the current-loop board, which has an onboard micro fast 
enough to translate Baudot on the fly. And the receive light stops 
flickering at the same time the write timeout message pops up.

Does anyone know how I can extend the timeout parameter... is this a Windows 
networking problem, or something flaky in the freeware serial-TCP program?

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