07-29-2021, 12:40 AM
I looked at the documentation for Telnet and there is in fact a command to set the ESC character(s) called "TNESC". So, that could be causing this issue if the escape character (or 2 byte character pair) is being changed from the standard default of ~ (0xFF). I probably should record whatever Telnet command(s) your BBS send and see what those are. Technically, when a device sends a Telnet request and gets a DON'T/WON'T response it is not suppose to assume anything about the client. Telnet sends a special character (0xFF by default) to tell the connected device that this is a Telnet command coming through. If the 2nd byte sent is also 0xFF then the byte is suppose to be interpreted as just a single 0xFF coming through and it's not really a Telnet command sequence about to occur. The TESTFILE I put together and uploaded/downloaded successfully on your BBS only contains a SPACE character (0x20) or a CR character (0x0D), so there would never be an escape character sent. There are a couple of different "standard" escape characters that are used, but I need to determine what your BBS is sending on startup - maybe it's not and the UDS10 just decides to use its own special escape character. We could figure that out by creating a series of files full of various characters and by process of elimination figure out what escape character is being used. If I knew that I could create a function to set the Telnet escape character as a new modem command. I spent a great deal of time on this Telnet vs. Raw thing, and I would highly recommend the program that I used where I could change between Telnet and Raw connections on the fly, and that is a program called "ZOC8 Terminal". You can Google that to find the download link. This is literally the holy grail for this type of testing because it has every file transfer protocol known to mankind, and you can add an external one if you wanted to create a custom protocol.
I also looked at the manual for the UDS10 and you should have the 'pack control' set to 00 and the 'Telnet terminal type' set to disabled.
I also looked at the manual for the UDS10 and you should have the 'pack control' set to 00 and the 'Telnet terminal type' set to disabled.