Something I kick myself every time I think about it was an old desk calculator I was given as "junk" by the owner of the first software development company I wo

Something I kick myself every time I think about it was an old desk calculator I was given as "junk" by the owner of the first software development company I worked for. I was 18 years old, and loved to get old electronics to tear apart for the parts, and this calculator was no exception. It was completely transistor based, and used nixie tubes for the output. And it had a memory function! But it didn't work properly, and so I dug into it. All the while wondering where inside was the "memory function" - I didn't see anything that looked like memory, just tons of transistors. But there was one curious thing - a metal box, very light weight (made of aluminum or something), with four wires leading in and out of it (two on one corner, and two on another). It was hermetically sealed, and so I broke out my tools and attacked it with gusto. Inside, attached to some ceramic "knobs" which had the wires attached where they led it - was a coil of wire - 2 or three loops. What was it for? I had no idea - and tossed it aside. In the end (after a couple of moves, meeting my now wife, etc - you know, life), I didn't even keep the nixies - those got sent to goodwill or something. It was only much later did I realize what I had destroyed. This was long before today's modern internet - circa 1992 or thereabouts - so I didn't have any easy way to look things up short of traveling a good distance to the library. I honestly wish I had kept that calculator whole; it would have gone nicely with the small "computer museum" collection I have going today (star of it is an Altair in desperate need of a good cleaning and restoration). But back then, I was just a dumb kid, doing dumb things. Ah, well.