This one was very difficult for me, in part because it has been written about heavily in the modern day. This may not have been the best question for this format—but I made it work.
(As a reminder, sources may be included in the alt-text of images for space and flow reasons.)
In the years before the device’s invention, Shannon became known for his interest in chess-playing machines, even writing an article for Scientific American about them in 1950.
https://www.paradise.caltech.edu/ist4/lectures/shannonchess1950.pdf
While there, Minsky developed a variety of machines—facilitated by a budding relationship with Shannon. “We hit it off because both Shannon and I were addicted to making interesting new mechanical devices,” Minsky said in an oral history.
Sounds like a pretty great internship. During that same oral history, he described the exact process of developing the machine.
Spencer Gifts later sold a variant that actually made the useless device useful—it turned the device into a bank that grabbed your quarters and stored them.
Not bad.