A 1980s toy robot arm inspired modern robotics

It was made for Radio Shack by Tomy, who made lots of battery operated toys in that era that were very complex and clever amalgamations of plastic parts. My sister had Tomy's 'Dream Dancer', which was obnoxiously loud, though you don't see that in the advertisements. She never got a second set of batteries once the Christmas day set gave out.

https://www.youtube.com/watch?v=0K8ZP1pnP78

Yep. Sold in the UK as the Tomy ROBO-1. Had great fun playing with it, never knew people had hooked them up to computers. Echoing others' comments, the drive was noisy even when stationary. And it didn't seem to have any sensors to let it know when it had reached the limit of any particular motion. Instead the plastic gears would start to skip loudly with a usefully intuitive "if you keep doing that I'll break" sound.

They even made "fake" electronic games like Blip -- a version of Pong that was electromechanical rather than electronic. Presumably at the time that was a cheaper way to do things, but like mechanical watches it is in a way more impressive than using electronics.

https://en.wikipedia.org/wiki/Blip_(console)

We had Blip and a baseball game that tried to look like an electronic game but we instantly knew it was inferior to the "real" thing. Looking back on it now, the mechanical games were more impressive, even if the electronic games were more expensive due to the various ICs.

Though Blip used batteries, it didn't go through them anywhere near the rate something like Head-to-Head football did. The baseball game was completely human powered, making them both far more useful in our rural area where batteries weren't available without a trip to town. Plus batteries were an added expense.