The HP calculators were so well designed. In college, a HP salesman stood before the engineering class and hurled a TI calculator at the cement wall. It exploded. Then he threw the HP calculator against the wall. It bounced off the wall. He picked it up and followed up with…. “Ok give me two numbers…”
Then a TI employee showed up, spent a week rebuilding the TI, and followed up with "Ok, give me the first number and an operation..."
I was a sophomore EE student when these came out. There were debates about whether to allow calculators in the classroom, somewhat irrelevant to me, since the price was out of reach anyway. Then the ME department made a deal to order in bulk, answering the debate, and making the marvelous machine somewhat affordable. I begged my father, and he fronted me the $271.40 (the HP-45 had just come out, so the 35 came down in price). Glorious days!
This seems to be a summary of the story at http://www.hp9825.com/html/the_9100_project.html, written by people who do know what a Q-meter is, have heard of Olivetti, and cite their sources.
People take ubiquitous calculating power for granted today. But back in the day, a portable or semi-portable machine able to do math in milliseconds was magical. It was as cutting-edge as ChatGPT, something that came straight from Science Fiction.
I am thankful my father-in-law gave me his HP-35 purchased in the early 1970s. With it came a metal case with a lock and a base you would bolt to your desk. It was a precious item back then.
Thankfully the power supply still works so I can take it out every so often and enjoy the history of it.
I've got my HP 32SII on my desk right now. Nothing beats a physical keypad with RPN.
Such amazing devices
RPN was what folks used before FP was created, to make other folks feel dumb.