Haven’t had time to go through the entire article, but right off the bat, it’s wrong.
The HP-12C was NOT the first HP calculator with RPN.
I got the HP-35 in 1972 when it came out, and the HP-45 a year later, and both used RPN
The ‘35 was the first scientific calculator.
Please don’t hold that against the article. It’s a nice piece on how much soul is contained in that hunk of electronics.
Certainly not HP’s first calculator with RPN. Had a programmable i cannot recall the number of, red LED display, very short battery life, like barely enought to get through an exam. had to keep turning it off to make it.
Programming was fun, they gave you the code for a moon lander, adjust the burn rate and try not to use it up too soon.
Got so used to RPN I can barely use the other style, sort of like driving a manual vs. auto. Far faster method, likely why most EE types prefer it.
It cleary was not HP's first RPN calculator, but it may have been the first FINANCIAL calculator with RPN. It unquestionably is HP's most successful RPN calculator.
HP came out with a new model a couple of years later, but no one bought it and they kept on selling the 12c. It amazes me that they still sell the same model calculator over 35 years later.
Yes, I got the HP 45 when it first came out, and after I learned RPN and the 4 register stack, I wanted nothing else! I still have it and an HP 25C, but nothing has compared to the 45 for me since. As an engineer and surveyor, I took it to the field with me and was amazed at the geometric calculations that I could perform with it!