Built a second RS232 interface tonight, and tested Operation Terminal.
The interface relies on a valid DCD line upon connect, and RI line must be low. DTR/DSR can't be left high, but DCD and RI hold the key.
I moved around in the game to get both people in the same room. I don't know much about how to play it.
After moving a bit, the system loses sync and states "DATA DILEMNA". It then resynchronizes and gameplay continues. I left RTS and CTS off of my interface, so I am thinking the game needs valid signals there as well.
Anyone want to play?
I'll get Modem Wars going tomorrow night or Saturday.