After SSH, Telnet client software example for Arduino IDE is available on project repo.
This software can be used to access the Minitel service hosted by teletel.org which provides an authentic minitel experience via telnet. Many thanks to him !
There are other minitel services available via websocket: Sample code coming soon
We can connect to BBS as well, but I have to admit that it is slow and graphically limited.
Here are some screenshots: