IBM introduces “Pointing Stick” (TrackPoint) (1990) (youtube.com)

Noice find. TBH, on my T480, I only use the trackpad because the pstick is a smallish, delta-only pointing device that takes too long for me... it's too much like moving a cursor around with a joystick for my taste. YMMV and there are different cursor-moving religions.

Otherwise known by its NSFW name, the 'clitmouse'.