I can't say when the computerized versions came into use but I know that in the mid 70's I was using a Lucas odometer in conjunction with my wristwatch and a memorized gear chart. "Intuition" played an important role too. I bought my first cyclometer in the 90's when my Lucas disappeared while the bike was in a LBS for repairs. I have always had good luck with the new things and now have a wireless version. Much better; the wires really did clutter the bike. Also, would anyone be interested in a Scheeren handlebar stem? It is pre-1974 for sure as I acquired it then. Never used but is scuffed from storage over the years. Contact me at email@example.com if interested.
Paul Patzkowsky, Longmont, colorado