Cool! I have one of the cheap old standard Casio calculator watches. I also have several altimeter and variometer watches from when I was hang gliding, along with an old camera watch. I guess my wife had a fairly good idea that it would cause my dormant ETF (Electronic Trinket Fever) to flair up.
Dunno how he kept it working, or how he worked the tiny buttons. He was a little guy, no way my fat fingers could work it, nor my eyes see it.
Absolutely. I bought a 45 when they first came out. Expensive, for sure, but it lasted many years before it died. There's a bit of a learning curve with RPN, but once you got over that, you could fly through complex calculations with confidence. Now, even for simple stuff, it feels unnatural and counterintuitive to use a calculator with an equals key.