I'm trying to setup a 80's service with Mystic BBS (that runs on telnet), including a dial-up access with a U.S. Robotics modem connected to the serial port of the server. I succeeded with mgetty:
/sbin/mgetty -D -a -x6 /dev/ttyUSB0
This brings the Ubuntu login on the remote client, that I can replace with the output of telnet on localhost, configuring the process that is started upon the connection is established. The problem is that mgetty requires the caller to enter an existing username on the server before he can get to the welcome screen of Mystic.
So, I switched to agetty: it has an auto-login feature that will skip the first step and it will directly bring the user to the telnet session using a conventional non-admin linux user. Then the user will login or register to the BBS service.
Unfortunately, I can't get it to work:
agetty -I 'ATE0Q1&D2&C1S0=1\015' ttyUSB0 vt100
With this command I can connect from the client, but nothing is shown on the terminal. The connection is stable, but nothing seems to be transmitted. If I send some strokes from the terminal and I monitor /dev/ttyUSB0 with screen on the server, I can see garbage characters that arrives, but everything is scrambled. Same thing if I send strokes from the screen session on the server, some "brick" characters are shown on the client terminal.