Anyone familiar with Reverse Polish Notation?

[bleedingheart]

just had to follow with this one after seeing the slide rule post...

[Huckebein the Raven]

1. Isn't it as follows:

1+3*4 becomes 134+* ?

[bleedingheart]

2. actually 134*+

[jmowreader]

10. No, that wouldn't work

1 <enter> 3 <enter> 4 + * would equate to 1 * (3+4). If you did that, not only would you get the wrong answer but someone from HP would come to your house and kick your ass for multiplying anything by 1. (It's part of the extended service plan they used to offer on the HP-41CX.)

To get 1+3*4 to work properly on an RPN calculator you'd do 1<enter>3<+>4<*>.

[Huckebein the Raven]

11. *slaps forehead*

sorry about that. I've only used RPN once.

[Briarius]

3. I am!

I got a RPN calculator a couple years back sans manual. It was a challenge to learn, but now that I've been using it for a while, I have problems with "normal" calculators.

[bleedingheart]

4. I got an HP calculator years ago that used RPN....and like you

I have a hard time with "normal" calculators....

[The_Casual_Observer]

5. 1 ent 1 + ... = 2

I really miss those calculators. My first calculator was an HP35 it cost 289.00 - in 1973.
the best part:
(2 + 4)*(9 +1) = 2 ent 4 + ent 9 ent 1 + *

[bleedingheart]

7. I still have my HP28C and it cost around $200 in 1987

I recall asking my mom for it when I started engineering school...and she was just flabbergasted that a calculator would cost that much...

Nothing like a calculator that can handle matrix operations and differential equations...

[The_Casual_Observer]

9. I had to have it because I was bad at getting the decimal in the

right place with a slide rule, particularly in chemistry. My dad would bring home the HP 45 sometimes, a handsome one that read little thin plastic cards along the top. That one was even more expensive. All the matrix and DE calculations were done using punch cards, but that is another story.

[Hans Delbrook]

6. My husband (the ex-physicist) has an RPN calculator

Every time I pick the damn thing up I have to re-learn how to use it. This biologist doesn't much like math in the first place - tricky math is just that much worse!

[Sannum]

8. I used to....

But I forgot it:P

[TreasonousBastard]

12. Had an HP-45...

years ago, and would use it today if someone hadn't stolen it. Had a lot of programs I wrote in it, and it was slow but it worked.

I vaguely remember a downloadable Windoze RPN calculator somewhere, but I would use it so little it doesn't make much sense to install another calculator.

RPN makes so much more sense, particularly when doing equations. But, most people just do basic arithmetic and didn't get it.

(There's a sliderule post? We were talking sliderules on another list I'm on. Seems everyone my age had one. Or many.)

[Sgent]

15. Used to have a 48G

when I switched to business, I wound up trading for 10B and some other stuff(great, but slow). RPN is great once your used to it.

[ChemEng]

13. My calculator (a 20 yr old HP) is RPN

and it is hell for me to try to use someone elses TI calculator.

[gbwarming]

14. Waste your evening here>> http://hpmuseum.org/

My first RPN calculator was a National Semiconducor Scientist PR - Programmable, but no conditionals or looping and terrible non-tactile keys. Best overall RPN calculator ever has to have been the HP-41.

http://hpmuseum.org/

[TreasonousBastard]

16. HP-41C ! That's the one I had...

not the HP-45.

The programming was similar to FORTH, with the direct memory access and stack manipulation.

Astronauts took the thing up with them, and I remember computer magazines including them in the speed benchmarks. They were always on the bottom, but you couldn't put a Trash-80 or CP/M machine in your shirt pocket.

Aside from no real graphing functions for those who needed them, it was probably the best calculator ever designed.

(Lemme see if there's any on eBay...)

on edit:

eBay's got two-- a 41C at $44 and a CX at $113.

[pnorman]

17. My first "good" calculator was an HP-45 (in 1975).

RPN made a lot of sense then, particularly with complex equations, involving one or more levels of 'nesting'. In those days, all you saw was a single number on a single line ... NO operators, and NO parenthesis. With RPN, instead of layers of parentheses, there was a 4 level "stack" (which you had to pretty well keep organized in your head).

I never felt all that 'comfortable' with RPN, and as soon as newer models came out, with operators and parentheses displayed (almost as though it was on paper), RPN seemed (to me) to no longer be worth the effort. A further improvement was an Equation Editor, which displayed it almost like it was in the book. And then came graphic calculators ... it's STILL almost magic to me.

But my FIRST LOVE was a slide-rule. I had seen one in a five & dime store when I was age 10 (a 25 cent "Lawrence", and pretty flimsy). I bought it, and finally figured out how to work it ... I was HOOKED for life!

pnorman