There was a day they were demonstrating the first commercially available harddisk from 1956 [0], it would be one thing to see it behind glass but the volunteers had built an arduino interface to drive it and interface it to bring it back to life, and hearing them explain how everything works with the requisite enthusiasm was a great experience for a vintage computer nerd. That sucker is pneumatic !

[0] https://www.computerhistory.org/storageengine/first-commerci...