This one is new to me, despite being a kid in the 1980s, the Armatron, a robotic arm from Radio Shack. Here are some videos I’ve had open in tabs for weeks now, so offloading here for safe-keeping:

Apparently despite having some minimal electronic parts, the device is mostly mechanical.

There was also a mobile version:

This video shows the guts of how the mechanism and gearbox work:

All in all, seems like a really cool toy! I wish I had one in good working order to experiment with as a drawing tool.