5 ms·

It took awhile to learn RPN in undergrad in electrical engineering. But, once you learn it, it is so much easier to solve problems and it is much more efficient

It took awhile to learn RPN in undergrad in electrical engineering. But, once you learn it, it is so much easier to solve problems and it is much more efficient. You never go back, and you are less likely to make errors entering in equations compared to your peers. This is important on timed exams. I prefer to always use RPN. MacOS has an RPN mode on their calculator, which one can activate by pressing command + R. On my iPhone I have an app called i41CX+, which is an HP-41CX emulator. I highly recommend the app, as the developer is constantly updating it. It probably is the most updated app I have of all of my apps. Also apparently there are some companies that recreate old HP RPN scientific calculators: https://www.swissmicros.com/products https://www.swissmicros.com/products

pwg 6y ago
My 'desktop' calculator on my Linux machines: http://lashwhip.com/grpn.html http://lashwhip.com/grpn.html (yes, I know that xcalc has an HP mode, but I only learned of that mode long after I'd begun using GPRN. The calculator on my Android phone (I 'disabled' the maker installed one): https://play.google.com/store/apps/details?id=org.efalk.rpncalc&hl=en_US&gl=US https://play.google.com/store/apps/details?id=org.efalk.rpnc... And I've still got my original 80's HP-15C.
ajsnigrutin 6y ago
yep, rpn is great! And since you're solving part by part, it's easier to spot mistakes in calculations. Going back to algebraic is pretty much impossible... luckily, there are many rpn calculator apps for phones.
senkora 6y ago
Emacs calc-mode is RPN by default as well.
- tonyarkles 6y ago
  calc-mode is wholly responsible for my HP49G+ not having had its batteries replaced in a few years. :D
ghaff 6y ago
>On my iPhone I have an app called i41CX+ The dev sent me the upgraded one after I reviewed the free(?) one in CNET years ago. I used an HP-41CV with various expansion packs for years. It doesn't have the same feel as the sadly broken physical calculator of course but I still like it. I basically don't anything these days more than simple arithmetic these days though--and if I did I'd use a computer. (I have been tempted by the Swiss Micro models but that would be a pure nostalgia-fueled buy on my part.)
ajarmst 6y ago
My daughter is at the learning algebra stage. I note that the way they teach kids to parse algebraic notation is by building an infix operation tree. If they’d just take the natural next step of discussing postfix (and prefix) traversal, everyone would think rpn natural.
jjav 6y ago
RPN is so nice and efficient, can't imagine using anything else. I like that the OSX calculator does RPN. But mostly I use my old 28S which is next to my keyboard always. Also have a 50g on the desk, but I prefer the 28S.
- ghaff 6y ago
  After using a 41CV for years, I bought a used 28S off someone. I just never cared for it. Probably just too accustomed to the more traditional RPN calcs.
- tzs 6y ago
  I get annoyed by the ways the OS X calculator deviates from HP RPN. The main one is that the pi and e keys act as if they are invoking constant functions that return pi and e, respectively. On an HP calculator, the pi key enters pi. That may sound like the same thing, but it is not. Consider this sequence: 2 ln pi x On my HP 15C the result is to multiply the natural log of 2 and pi. Same thing with PCalc on my iPhone. With OS X calculator the result is either pi with an error beep if you started with an empty stack or pi times whatever was on the top of the stack if you started with a non-empty stack. The "2 ln" part leaves ln(2) on the stack. On the HP and other sensible calculators the pi key pushes pi. On the MacOS calculator, it replaces the top of the stack with pi. They also had some problems where if you did a function and then started entering digits it would overwrite the function result, but I think they fixed those. I've seen what I thought was that problem recently, but when I finished entering the number and hit enter or invoked a function on the number, the previous function result appeared second on the stack, so it apparently is just a bug in displaying the stack.
  - taeric 6y ago
    That sounds like a bug. Why would any value replace the top of the stack?
  - jjav 6y ago
    Interesting, that's certainly broken of the OSX calc. Admittedly I only use the OSX calc for very basic +-*/ operations. Anything more than that and I grab the 28S!

pwg 6y ago

My 'desktop' calculator on my Linux machines: http://lashwhip.com/grpn.html http://lashwhip.com/grpn.html (yes, I know that xcalc has an HP mode, but I only learned of that mode long after I'd begun using GPRN. The calculator on my Android phone (I 'disabled' the maker installed one): https://play.google.com/store/apps/details?id=org.efalk.rpncalc&hl=en_US&gl=US https://play.google.com/store/apps/details?id=org.efalk.rpnc... And I've still got my original 80's HP-15C.

ajsnigrutin 6y ago

yep, rpn is great! And since you're solving part by part, it's easier to spot mistakes in calculations. Going back to algebraic is pretty much impossible... luckily, there are many rpn calculator apps for phones.

senkora 6y ago

Emacs calc-mode is RPN by default as well.

tonyarkles 6y ago
calc-mode is wholly responsible for my HP49G+ not having had its batteries replaced in a few years. :D

ghaff 6y ago

>On my iPhone I have an app called i41CX+ The dev sent me the upgraded one after I reviewed the free(?) one in CNET years ago. I used an HP-41CV with various expansion packs for years. It doesn't have the same feel as the sadly broken physical calculator of course but I still like it. I basically don't anything these days more than simple arithmetic these days though--and if I did I'd use a computer. (I have been tempted by the Swiss Micro models but that would be a pure nostalgia-fueled buy on my part.)

ajarmst 6y ago

My daughter is at the learning algebra stage. I note that the way they teach kids to parse algebraic notation is by building an infix operation tree. If they’d just take the natural next step of discussing postfix (and prefix) traversal, everyone would think rpn natural.

jjav 6y ago

RPN is so nice and efficient, can't imagine using anything else. I like that the OSX calculator does RPN. But mostly I use my old 28S which is next to my keyboard always. Also have a 50g on the desk, but I prefer the 28S.

ghaff 6y ago
After using a 41CV for years, I bought a used 28S off someone. I just never cared for it. Probably just too accustomed to the more traditional RPN calcs.
tzs 6y ago
I get annoyed by the ways the OS X calculator deviates from HP RPN. The main one is that the pi and e keys act as if they are invoking constant functions that return pi and e, respectively. On an HP calculator, the pi key enters pi. That may sound like the same thing, but it is not. Consider this sequence: 2 ln pi x On my HP 15C the result is to multiply the natural log of 2 and pi. Same thing with PCalc on my iPhone. With OS X calculator the result is either pi with an error beep if you started with an empty stack or pi times whatever was on the top of the stack if you started with a non-empty stack. The "2 ln" part leaves ln(2) on the stack. On the HP and other sensible calculators the pi key pushes pi. On the MacOS calculator, it replaces the top of the stack with pi. They also had some problems where if you did a function and then started entering digits it would overwrite the function result, but I think they fixed those. I've seen what I thought was that problem recently, but when I finished entering the number and hit enter or invoked a function on the number, the previous function result appeared second on the stack, so it apparently is just a bug in displaying the stack.
- taeric 6y ago
  That sounds like a bug. Why would any value replace the top of the stack?
- jjav 6y ago
  Interesting, that's certainly broken of the OSX calc. Admittedly I only use the OSX calc for very basic +-*/ operations. Anything more than that and I grab the 28S!