Build your own teletext decoder published by ETI magazine (Electronics Today International), July 1979. From here.
A Minitel prototype presented in 1979, via.
Stills from Graphic Variations on Telidon by Pierre Moretti, 1979 or 1980. The Telidon System was a videotex service developed by the Canadian Communications Research Centre (CRC) during the late 1970s and early 1980s.
Video here. Post updated in 2024.
An eerie ad for Prestel, which was a videotex service in the UK launched in 1979. A bit like interactive teletext.