Thanks, all. Now that I see it, it comes back to me. It’s been so long since I’ve had to use either one, I got the terms mixed up.
I just started learning PostScript, which uses RPN, which is what brought it to mind.
It’s probably because we used to call it “Backwards is Normal Form” in school that I confused it with Reverse Polish Notation.
I bought my HP 16C scientific calculator in 1982. It still sits on my desk in its little wooden stand. I use it nearly daily, albeit mainly for simple addition and subtraction. How many other electronic gizmos still work perfectly, and usefully, after 34 years?
I have a terrible time using a conventional calculator - the RPN has seeped into my bones.
I had an HP 11c in college decades ago but then lost it a few years after school. But then a few years ago, HP announced a special anniversary edition of the calculator, which I bought (for around $200, I think). Note that the original calculator was not cheap. I think I paid at least $200-300 for it in 1985.
And we also had races between RPN calculators and ones doing algebraic notation. We were such nerds. (Those using the RPN calculators won every time of course.)
That would be overkill; it’s easy enough to describe an infix syntax for mathematical operations using BNF, so that’s what’s done in every Baby’s First BNF Example I’ve seen. This is done in The Unix Programming Environment to introduce yacc and lex, for example.
Anyway, few enough people use strict BNF anyway; EBNF (Extended BNF), which is more convenient, is what’s actually implemented by most compiler-compilers.
And, while we’re all talking about RPN calculators, I still have and cherish an HP-48GX which saw me through most of high school and all of college.
It’s some kind of sausage.
Yep, GNU came first. The GNU acronym comes from GNU is Not Unix. It’s one of those silly recursive acronyms from the 80s, like PINE (Pine is Not Elm, though at some point it got officially changed to Pine Internet News and Email).
Since this thread is now thoroughly [del]pizzled[/del] hijacked, I might as well mention that the GNU Project’s perpetually-unready Official Kernel is called HURD, which stands for “HIRD of Unix-Replacing Daemons”, and HIRD stands for “HURD of Interfaces Representing Depth”.
Yep: A pair of mutually-recursive acronyms.
Heh, I was just telling a student a couple of hours ago that I wasn’t sure how some of the functions on his TI worked, because I’m more familiar with HP, and HP is better once you learn to use them, but unfortunately they haven’t made any calculators in years.
And my primary calculator is an HP48 emulator on my phone. All the RPN stack goodness, but it fits in my pocket easier, and it’s faster.
Not that I know. Any decent calculator today allows you to type in the actual equation or expression in full. And if you have access to a computer you can do that in wolfram alpha without even needing a separate program.
What kind of hoops they make you jump through on engineering exams around the world to show you understand the math without the help of professor google I don’t know. There might be schools where they rent out 20 year old RPN calculators.
I bought my HP 16C in 1982 for $120 - According to Google, that’s equivalent to $301 today.
But “typing in the actual equation or expression in full” usually takes a lot more keystrokes than RPN. Even my preferred ancient HP 48s had a way to do that, and it was easier to use than most other equation editors I’ve seen (even ones that had the advantage of a mouse), and it still hardly ever got used, because RPN was quicker.