Back in the 70s and 80s, there was a little piece of technological magic known as Teletext. Basically, it allowed the broadcast of text, and crude text-art, over unused TV spectrum, so long as you had a special decoder. Very proto-internet. And so of course, it was used for pornography.
There are a few places online that archive this wondrous, alien stuff. Boing Boing points to a few Tumblrs (lordnkon and Text Mode) which are naturally full of smut, as this fascinating article on Dangerous Minds about the history of the German teletext-porn scene specifically. You should definitely check it out if your interested in the how and why.
In the meantime, what follows is a collection of but a few (obviously) NSFW porno pics, for your textual titillation:
[Dangerous Minds, lordnkon, Text Mode via Boing Boing]
GIFs from lordnkon
