Must be a slow Saturday if this is near the top of HN. But if you are interested in hacking the old French Minitel, you may enjoy my other two posts:
Voiding the warranty on a 1993 Minitel 2 to run arbitrary firmware https://blog.jgc.org/2022/03/voiding-warranty-on-1993-minite...
Using a Minitel 1B as a serial terminal https://blog.jgc.org/2022/03/using-minitel-1b-as-serial-term...