Télétel, the French Internet of the 80s — How did it work?

I suppose, most readers would not believe me if I write that already in the 80s the internet-like system was already working in France. But it was really so.

Minitel 1 © Image by author

How was it possible? Let’s figure it out.

History

Computers became connected to the network many years ago (the TCP and FTP protocols, which are still in use today, were actually invented in the 70s), but this technology was mostly available only for universities and large governmental institutions like NASA. But the idea of providing online services to ordinary people was tempting. Later electronics became cheaper and more affordable, and the dream started to come true. At the end of the 70s, the Videotex protocol was invented — it allowed users to receive information using the modem connected to the telephone line. The idea was based on using not a fully-fledged computer, but a “dumb terminal”. The terminal was only capable of displaying data on the CRT screen, it had a minimum amount of components, and all processing was actually made at the remote “server” side. This architecture could reduce devices cost, and companies in different countries started making experiments and prototypes. Most of such services were introduced but never became commercially popular, like a Viewtron in the US (the terminal price was about 800$ with a…