Calculator for engineers of a certain age...

As I get older, I find it a pain to get out the graphing calc with a hundred teeny buttons for every little thing, and I don't always have my computer nearby. Is there a desktop-style physical calculator that's just there in the real world and that I don't have to open a damned app or navigate to just to do basic stuff? Maybe some basic scientific notation and unit conversions? You know the ones that tax accountants have that have a couple extra functions useful to them? Like that, but for me. Bonus points if it's steam powered, I guess.