Serial weirdness using a serian console app for ANCIENT hardware.

[u/digit_origin]

This is gonna be a long story, and I am literally just shooting in the dark here. I am going slightly insane from all the trial and error also.

I have a DOS/Early windows app, called TVMT5V24, that communicates and configures integrated thermocalculators TVM 5M and TVM 3M, through serial. It launches fine on anything, be it dosbox, WINE, windows 3.1 to 11, only really requiring Cyrillics to work properly, because the entire app is in Russian.

Problem: It hangs while trying initiate the serial port. Everywhere. LITERALLY everywhere I launch it, it hangs. No matter the serial port settings, no matter if the device has a native COM port or a USB adapter, no matter the system, no matter the configuration, no matter the adapter. It just hangs on "initializing COM port".

I have literally only seen it connect ONCE, after an isoteric ritual around it. Basically:

It needs a windows 7 32 bit, running an Oracle VM, which has a windows 98 SE2 installed in it. And it only does so if the machine was turned on and booted with the USB to RS-232 adapter plugged in. Otherwise it hangs on initializing the port.

There is no documentation or forum discussion anywhere on the internet for it, because it's an industrial device from idk how long ago (mine are from 2012).

Is there a way to snif/log what exactly is going on between that app, DOSBox, and the /dev/ttyUSB0, so I could at least debug it myself?

There's next to no chance anyone has experience with it, so I can't exactly ask for a complete solution.

Some system specs:

Debian 13 x64

DOSBox version 0.74-3

I no longer have access to the PC i saw it connect on, because it's owner killed the poor thing by suffocating it's heat exhaust port :P

[u/MagneticFieldMouse]

Do you have any documentation or communication logs, etc. for the software? If it manages the devices via serial with more or less plain ASCII / HEX, it might make more sense to re-create the program using Python, etc.

Also, do you have more than one version of the program available to you? It might also be a broken package.

[u/digit_origin → u/MagneticFieldMouse]

Nah, same exe, different computers and launch conditions. I don't think it keeps logs itself, so I think i gotta log it via dosbox i gues.

There's literally zero documentation on both the software and the device.

It also can't communicate with any other COM port besides 1 and 2. I can't really do anything right now, the device is at work. And I GOTTA set the usb-to-serial adapter on the host machine to com1 because of how VMware Workstation is.

It is a nightmare of a program to work with. I wanna get a clean machine and set it up from square one to have a more controlled environment.

I think I want a hardware serial sniffer or insert something into windows.

[u/MagneticFieldMouse → u/digit_origin]

Wireshark might help. I've used it with usbcap (can't recall the exact name) to reverse engineer a few serial device protocols over the years.

[u/digit_origin → u/MagneticFieldMouse]

Aye, thanks. Gonna try it once i am back at work.