I have a vintage fx-82 calculator [1] that still works. My father bought it when he started working after his engineering, which was passed on to me for my engi

I have a vintage fx-82 calculator [1] that still works. My father bought it when he started working after his engineering, which was passed on to me for my engineering, which was then passed on to my brother for his engineering - which ended 12 yr ago. Last checked the thing a few months ago, it works barring a few problematic keypresses. I am nearly convinced it's alien technology at this point. [1] not mine, but this model: https://www.ebay.com/i/123734880177 https://www.ebay.com/i/123734880177