It must have been back sometime in the early 80’s. A scientist friend of mine brought home a suitcase-sized “laptop” complete with modem. He dialed into the mainframe at work and we played a dungeon crawler game late into the night.
It was all text based, but I remember how we were so completely mesmerized by the experience of typing “walk” “look” “look up” “look down” “run away” etc., etc.
It was so massively crude by today’s standards, but even then it was clear to us that this was a transformative technology.