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The early history of HP calculators

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Re: The early history of HP calculators

#31

Post by ZenoArrow »

MegaDeKay wrote: post #24
siberianbear wrote: post #23

Wow, this is bringing up some memories of my childhood. One of my childhood friends had a father who was a licensed surveyor and civil engineer. He showed me how to write programs one one of these calculators. I was fascinated with it, and started writing simple programs to do obscure calculations. After I showed him what I had figured out, he showed me how to remove the faceplate and access a special test mode by pu…

Actually, to do "3+4" you enter 3 4 + That's it. Note that this is one keystroke less than the regular calculators used by mere mortals, and that is why RPN rules. Source: my daily driver HP-15C that I've had since around 1985. Works perfectly and has only gone through two or three sets of batteries. I'd swear it was solar powered.

Isn't that the same number of keystrokes?

[3] [+] [4] [=]

[3] [Enter] [4] [+]

Both use four keystrokes.

Re: The early history of HP calculators

#32

Post by tyingq »

pmoriarty wrote: post #9

I've never used an HP calculator, but I've recently been getting interested in emacs' calc, which is also RPN. Could someone who's used both talk a bit about how they compare? Are calc and emacs missing something that made HP great?

You can try an HP48 here: http://www.poleyland.com/hp48/index.html

Re: The early history of HP calculators

#33

Post by jaclaz »

ZenoArrow wrote: post #31
MegaDeKay wrote: post #24

Earlier quoted context omitted.

Actually, to do "3+4" you enter 3 4 + That's it. Note that this is one keystroke less than the regular calculators used by mere mortals, and that is why RPN rules. Source: my daily driver HP-15C that I've had since around 1985. Works perfectly and has only gone through two or three sets of batteries. I'd swear it was solar powered.

Isn't that the same number of keystrokes? [3] [+] [4] [=] [3] [Enter] [4] [+] Both use four keystrokes.

Yes, bad example.

See here:

http://calculatorauthority.com/why-use-a-reverse-polish-nota...

>For example, we want to compute “(13+3)÷(4×2)” using a calculator of algebraic notation (not a scientific one) then we have to do many steps to reach the answer. Firstly, we have to compute “(13+3)” and then we will save the answer to the memory of the calculator. Then we have to compute the calculation in the denominator i.e. “(4×2)” and we have to save this answer too to the memory of the calculator. In the end, we will bring both the answers and will perform the last operation of division. This procedure has taken a reasonable amount of time. This thing can be avoided by using RPN calculator. In RPN calculator, we have to insert just a single line expression as “13 Enter 3 + 4 Enter 2 × ÷” and the answer will be computed instantly.

More generally the use of a stack (in the case of some calculators an actually visible stack) helps a lot with complex formulas.

Re: The early history of HP calculators

#34

Post by paraplegic »

My introduction to programming was a 49 step programmable HP-25 which I borrowed from a friend in residence back in 1978, and subsequently just had to have one ... RPN got me interested in taking a FORTRAN course, and the following year I became an undergrad tutor and computer room assistant ... From lunar lander, to star trek on a mainframe, to a career in software development ... funny how career trajectories work ...

Re: The early history of HP calculators

#35

Post by jhbadger »

waynecochran wrote: post #29

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 th…

Basically 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.

Re: The early history of HP calculators

#37

Post by tremendo »

ZenoArrow wrote: post #31
MegaDeKay wrote: post #24

Earlier quoted context omitted.

Actually, to do "3+4" you enter 3 4 + That's it. Note that this is one keystroke less than the regular calculators used by mere mortals, and that is why RPN rules. Source: my daily driver HP-15C that I've had since around 1985. Works perfectly and has only gone through two or three sets of batteries. I'd swear it was solar powered.

Isn't that the same number of keystrokes? [3] [+] [4] [=] [3] [Enter] [4] [+] Both use four keystrokes.

Right, where RPN really shines is in more complex operations where other calculators need parenthesis to group sub-operations, whereas you can just push stuff up the stack, and it in turn can be rolled, swapped… definitely a nerds' tool of choice

Re: The early history of HP calculators

#38

Post by carussell »

jaclaz wrote: post #33
ZenoArrow wrote: post #31

Earlier quoted context omitted.

Isn't that the same number of keystrokes? [3] [+] [4] [=] [3] [Enter] [4] [+] Both use four keystrokes.

Yes, bad example. See here: http://calculatorauthority.com/why-use-a-reverse-polish-nota... >For example, we want to compute “(13+3)÷(4×2)” using a calculator of algebraic notation (not a scientific one) then we have to do many steps to reach the answer. Firstly, we have to compute “(13+3)” and then we will save the answer to the memory of the calculator. Then we have to compute the calculation in the denominator i.e…

[1 3 Enter 3 + 4 Enter 2 × ÷] is 10 button presses for RPN.

[1 3 + 3 = ÷ 4 ÷ 2 =] is also 10 button presses, and how I would have entered it on an infix $10 TI-30XA during an exam. (At least, it's how I would have entered it if the figures weren't so small.) You could argue that it's cheating to "cook" the input beforehand so that the '4×2' divisor becomes two '4' and '2' divisors, but then you would have to ignore that RPN requires its own pre-cooked input (and that of the two, the RPN form is the one that relies on a more extensive cook).

Re: The early history of HP calculators

#39

Post by brians »

zokier wrote: post #28
dm319 wrote: post #16

Getting good condition HP calculators can be quite expensive second hand. People interested in buying a new one should check out swissmicros [1]. They are bringing out an HP42s clone with quad precision decimal accuracy, which I'm looking forward to! [2] [1] http://www.swissmicros.com/ [2] https://www.youtube.com/watch?v=8LatjXPgLI8 EDIT: I don't have any involvement with swissmicros apart from anticipating their new…

One thing that has always befuddled me with HP calcs is their model numbers that don't seem to follow any rhyme or reason. How does the functionality of DM42 compare to for example WP34? And how does -48 compare, besides the relatively useless graphing capability? I see lots of people also preferring some other models (15, 16, 35, 41 etc), which I would have imagined to be strict subsets of these "juggernauts", but m…

The 48s show you four rows of stack at a time, and can use that to show a single long expression. That can be a huge difference—though of course, unlike the time when these were built, we have Octave and similar right there.

Re: The early history of HP calculators

#40

Post by vram22 »

agumonkey wrote: post #20
nemoniac wrote: post #19

Earlier quoted context omitted.

If you're enjoying that, you'll find even more connections with Forth, also a very cool programming language. https://en.wikipedia.org/wiki/Forth_(programming_language)

I love stack languages. Forth, Factor, Joy, Cat .. (all the concatenative crew). ps: there are some Chuck Moore talks on youtube that are worth gold. His CPUs are heaven

Can you please give links for those of his videos that you liked?
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