 If I recall properly, I don't think they really did; certainly not in the form they do today. It wasn't until I got a Commodore Amiga and played titles like Eye of the Beholder and the first Elder Scrolls game that everything changed.  In the early days of ZX Spectrum they didn't, but by the mid 00s SSI strarted to launch a series of AD&D games. I wouldn't call them really RPGs, but they were adaptations of pen & paper games, so...  