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When I started college in 1985, every Physics student had an HP41C. You were at a distinct disadvantage on an exam if you had an infix calculator. I still have
by waynecochran 9y ago
When I started college in 1985, every Physics student had an HP41C. You were at a distinct disadvantage on an exam if you had an infix calculator. I still have my HP41CX that my dad bought me in 1985.
Now I don't see any of the students using them. What happened? When I used to teach, I would write a large expression on the board and challenge students to a calculator duel -- me using my 1985 HP41CX and them using their lumbering infix calculator. I would always win.
The magic is the automatic saving of subexpressions on a stack. Once you got the hang of it, you would never want to go back to an infix calculator.
I have the HP41C app on my iPhone, but you miss the beautiful haptic feedback keys that the HP calc's had.
Actually, the very first programming course I ever took was a 2 credit course called "Programming Calculators" and we learned to program to the HP41. When a program was running, a little "bird" glyph would "fly" flom left to right across the LCD screen. I remember writing a program to get the bird to fly backwards. Silly, but fun.
Of course I had the Math Module that you could plug in and the magnet card reader. Anyway, I always wondered what happened in the intervening time that no one seems to use them anymore.
- jhbadger 9y agoBasically after the merger with Compaq in 2001, HP lost interest in their calculators. They still technically sell them, but they aren't advertised to any degree. Obviously since the advent of the smartphone the need for dedicated calculators is lessened, but as you say, the haptic feedback is nice and TI seems to be still selling a lot of calculators.
- deleted 9y ago[deleted]
- keenerd 9y agoThey were dying long before smartphones. Cheap Casio calculators happened. I have a little $15 Casio scientific calculator and it has been all that I've needed for college and professional work. But it can take integrals, derivatives and has a general newtonian solver. It covers everything except matrices. Those are miserable to do on any calculator so I'm not missing much. In all my life I've only ever seen two HP RPN calculators. One belonged to my high-school chem teacher, the other to a real estate agent. If there were a $30 RPN calculator with similar functions, I would use it. Edit: 18 years later and they still make it, https://www.casio.com/products/calculators/fraction-and-scientific/fx-115msplus https://www.casio.com/products/calculators/fraction-and-scie... Edit2: Looks like the most readily available RPN calculators are the HP 35S ($55) and HP 12C ($50).
- tragomaskhalos 9y agoYup - among us maths geeks at school in the 80s the HPs - especially the 41 - were the Rolls Royce of calculators, beautiful machines that few could afford, although even the high end programmable Casio that I settled for was pretty pricey.
- LanceH 9y agoI would say it was the tight integration of the TI8* into the classroom that did it. Everyone's first scientific calculator was more or less required by some course.
- hota_mazi 9y ago> The magic is the automatic saving of subexpressions on a stack. Once you got the hang of it, you would never want to go back to an infix calculator I was one of these smug HP calculator owners back in high school and college. I loved it and spent hours hacking on it (and also secretly enjoyed the fact that nobody borrowed it since hardly anyone knew how to use it). Years later, I started realizing that the reason why these calculators do take fewer keypresses to make calculations is because they borrow your brain to assist them. For example, you see `3 * (2 + 4)` and your brain has to identify the most nested parenthesis expression, type that in and work your way out. It works well enough for simple expressions but doesn't really scale very far beyond that. Remember this SETI program that used people's idle CPU's to scan sky pictures? I felt HP calculators had been pulling the same trick by borrowing your brain to calculate their expressions. I felt that I had been cheated but I wasn't really mad about it because I loved these calculators so much.
- ScottBurson 9y agoI don't think that's fair. Either form requires some mental stack space to convert to the other form. It's just that people are more used to reading and writing infix.
- dm319 9y agoYes, I find complex equations to be far easier to calculate in RPN. Even if you get stuck you have a useful intermediate. On algebraic I find I'm having to back pedal to sort out parentheses for lower order operators.
- antod 9y agoAgreed. Although getting a multiline display like the 42S or (gasp) 48S helped a lot with keeping track of the stack. edit: 42S not 42C
- hota_mazi 9y agoFor regular notation, you just type all the characters as you read them, including parentheses. This requires less mental activity on the person, as opposed to RPN, which forces you to first parse the entire expression and identify the most nested expression and process outward from that point on.
- CamperBob2 9y agoThe magic is the automatic saving of subexpressions on a stack. Once you got the hang of it, you would never want to go back to an infix calculator. Of course, you're comparing the HP41C to bad infix calculators, early ones that didn't support algebraic order of operations or explicit parentheses. It's worth remembering that postfix calculators exist not because they were ever the right thing to do, but because they were easier to implement with limited computing power. Forcing the user to keep track of the stack context was a clever hack on HP's part, but is no longer necessary or justifiable. And that's why you don't see many new postfix calculators these days.
- waynecochran 9y agoI'll still beat anyone w an infix calc.
- CamperBob2 9y agoIt would make a good demo to point to on YouTube when these debates come up, certainly. Closest thing I can recall was the contest that pitted a texting teenager against an experienced ham radio operator with a telegraph key...
- dm319 9y ago>What happened? I don't get it either. Even if HP lost interest, why didn't anyone continue with RPN (patents, maybe?). I think RPN is both better for learning at school (you see intermediates, and you learn operator order), as well as general use. I love that you can just get stuck in calculating without having to worry about getting it all in the right order at first. I'd love my children to use RPN when they reach that age, but there is a lack of RPN calculators on the market, a lack of knowledge at school and it may even be banned by the time they need to take an exam.
- CamperBob2 9y agoI love that you can just get stuck in calculating without having to worry about getting it all in the right order at first. Even better if I don't have to worry about it at all. That's why I'm using a calculator in the first place, and not scribbling figures by hand on a piece of paper.
- joezydeco 9y agoWhat happened is every high school mandating the use of the TI-35 and their brethren, making sure those kids are so used to working with infix calculators that they never approach an RPN.