## Inspiring the next generation of RPN users

General discussion about calculators, SwissMicros or otherwise
rudi
Posts: 28
Joined: Wed Nov 03, 2021 9:03 am
Location: Denmark
Contact:

### Re: Inspiring the next generation of RPN users

Walter wrote:
Thu Oct 14, 2021 6:53 pm
Peet wrote:
Thu Oct 14, 2021 6:27 pm
Walter wrote:
Mon Aug 07, 2017 9:39 pm
Well, YOU may get it if you really like that, of course -- but for kids? KISS: 8 levels cover everything which will ever happen to an intelligent person.
Is there any example in regular math (college or Abitur) where four stack levels are not enough? ...
Equations of this kind need >4 stack levels for solving:
.
stack_overflow.png
.
They don't look too difficult for school.
Well, actually:

Code: Select all

1
ENTER
2
+
9
ENTER
8
+
*
3
ENTER
4
+
11
ENTER
6
+
*
+
5
ENTER
7
-
10
ENTER
12
+
*
13
ENTER
14
+
15
STO ST L
R↓
16
RCL+ ST L
*
-
/

Which yields in -0.1930 on my ancient, but trustworthy 4 level stack HP-42S. Remember the L stack register, which can com in handy once in a while

Last edited by rudi on Fri Nov 05, 2021 5:02 pm, edited 2 times in total.
/Rudi

DM-42 (s/n 06999), HP-42S, HP-35s, HP-11c, HP-32SII (ex HP-41CV and ex HP-75C + a lot, really lot of a accessories)
dalremnei
Posts: 37
Joined: Thu Dec 10, 2020 11:32 am
Location: Scotland

### Re: Inspiring the next generation of RPN users

Peet wrote:
Thu Nov 04, 2021 4:58 pm
dalremnei wrote:
Thu Nov 04, 2021 4:47 pm
At that point, why not just use a calculator with textbook input? It'd be a lot easier…
Maybe this really is better for you. For me, RPN is not nostalgic but more suitable for my calculations than other input methods.
My point was mainly that 4 level stack isn't going to convert anyone to RPN except for hardcore calculator nerds like myself. RPN calculators need to compete against textbook input nowadays, so it's important that they can outperform textbook input calculators.
SwissMicros DM42, DM16L, HP 12c Platinum, CASIO fx-9750gii, fx-991ex classwiz, fx-CG50, CA-53W-1ER, TEXET fx1500, TI nspire CX II-T
Peet
Posts: 175
Joined: Tue Sep 29, 2020 12:01 am
Location: Germany

### Re: Inspiring the next generation of RPN users

dalremnei wrote:
Thu Nov 04, 2021 5:47 pm
RPN calculators need to compete against textbook input nowadays, so it's important that they can outperform textbook input calculators.
they always did
My programmable calculators - former: CBM PR100, HP41CV, HP28S, HP11C - current: HP48G(256kB), HP35S, Prime, DM41X, DM42
Walter
Posts: 2067
Joined: Tue May 02, 2017 11:13 am
Location: Close to FRA, Germany

### Re: Inspiring the next generation of RPN users

RPL := RePelLent (quoted: Valentin Albillo).

This topic shows up every once and a while. Actually, there are two schools:
1. Old school RPN users love a finite stack with top stack level repetition. RPN allows for quick and dirty programming.
2. A little less old school RPL users love an infinite stack (which can't feature a top stack level repetition obviously). RPL supports a more structured programming paradigm than RPN.
Both RPN and RPL programs are hardly readable for uninitiated people (IMO RPL programs are even a bit worse, but YMMV). Many experts claim RPL has a steeper learning curve.

Personally, I know you can solve every real-world problem employing RPN and an 8-level stack.
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dalremnei
Posts: 37
Joined: Thu Dec 10, 2020 11:32 am
Location: Scotland

### Re: Inspiring the next generation of RPN users

Peet wrote:
Thu Nov 04, 2021 5:57 pm
dalremnei wrote:
Thu Nov 04, 2021 5:47 pm
RPN calculators need to compete against textbook input nowadays, so it's important that they can outperform textbook input calculators.
they always did
Textbook input calculators internally have a stack much deeper than four levels, so, no.
SwissMicros DM42, DM16L, HP 12c Platinum, CASIO fx-9750gii, fx-991ex classwiz, fx-CG50, CA-53W-1ER, TEXET fx1500, TI nspire CX II-T
akaTB
Posts: 642
Joined: Tue May 02, 2017 1:56 pm
Location: Milan, Italy

### Re: Inspiring the next generation of RPN users

Walter wrote:
Thu Nov 04, 2021 6:07 pm
RPL := RePelLent (quoted: Valentin Albillo).
You know you have my vote here.
Walter wrote:
Thu Nov 04, 2021 6:07 pm
Personally, I know you can solve every real-world problem employing RPN and an 8-level stack.
Probably so. I know it should be well enough for me.
Greetings,
Massimo
ajcaton
-+×÷ left is right and right is wrong Casted in gold
Peet
Posts: 175
Joined: Tue Sep 29, 2020 12:01 am
Location: Germany

### Re: Inspiring the next generation of RPN users

dalremnei wrote:
Thu Nov 04, 2021 6:15 pm
Textbook input calculators internally have a stack much deeper than four levels, so, no.
Your considerations are more than 40 years behind the reality. Texas Instruments wanted to show off with the large "AOS stack" in the 1970th (9 levels in brackets + 8 open operations) in the TI 58/59 manual, the corresponding example in the manual only required a 3 level stack in RPN.

Even if some trains have a few hundreds of wheels, my car don't need more then 4.

For almost all typical calculations in schools and universities, 4 stack levels are not a restriction - on the contrary, this can help with structured work. For users who want more stack levels, HP also has RPL aka "Entry RPN" (big stack) alongside the classic RPN for around 35 years, but it has never been more popular then classic RPN.

In 2021, HP will be offering 5 RPN pocket calculators, but only one of them with Entry RPN. Even at Swissmicros, with more than 10 different RPN calculators, there is only one with Entry RPN and that even after-market. I think it's nice that there are such calculators for people who like or need it, but I think it's "special interest" and even worse for newbies to get started with because it can confuse how to understand and solve a calculation.
My programmable calculators - former: CBM PR100, HP41CV, HP28S, HP11C - current: HP48G(256kB), HP35S, Prime, DM41X, DM42
Walter
Posts: 2067
Joined: Tue May 02, 2017 11:13 am
Location: Close to FRA, Germany

### Re: Inspiring the next generation of RPN users

Maybe we can agree on 4 stack levels being sufficient in about 95% of all real life cases. That's enough for US-Americans. Personally, I need a greater confidence in my calculator solving my problems without stack overflow etc. And I don't want keeping track of the stack levels employed. So I'll choose 8 stack levels and simply enjoy being on the safe side.

And nowadys we can afford 'wasting' four registers for being safe.
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rprosperi
Posts: 1182
Joined: Mon Apr 24, 2017 7:48 pm
Location: New York

### Re: Inspiring the next generation of RPN users

I agree that it is sometimes, even if rare, useful to have need for more than 4 stack levels, and resources in the 43S plentiful, so it makes sense to have this option, though it does slightly complicate the 43S ecosystem as when one shares a program it must be clearly stated that 8-level stack mode must be enabled. Using such a program in the wrong mode will likely produce an unexpected error (best case) or inaccurate results with no warning (worst case).

What is far less clear is how one can conclude Americans can somehow all be satisfied with 4-levels, while non-Americans may sometimes need more? And this is especially odd in a thread debate among primarily non-Americans. Seems like some prejudice has been brought to the topic for no good reason, and it really has no place here. If I'm mistaken, and there is evidence of nation-dependent preference for number of stack-levels, it really should be shared before jumping to conclusions.
--bob p

DM42: β00071 & 00282, DM41X: β00071 & 00656, DM10L: 071/100
Walter
Posts: 2067
Joined: Tue May 02, 2017 11:13 am
Location: Close to FRA, Germany

### Re: Inspiring the next generation of RPN users

That was a joke for the initiated, coming from the fact that US-Americans are usually content with a confidence level of 95%, while people elsewhere are used to 99% (in statistics).

Sorry for making complicated jokes. Won't do it too often. And yes, I hate having to explain jokes.
DM42 SN: 00041 β
WP 43S running on this device

HP-35, HP-45, ..., HP-35S; WP 34S & WP 31S for obvious reasons; DM16L