Is there a free RPN stack emulator for writing 35s programs


Does anyone know of a free RPN stack emulator for the HP 35s? I'd love to write some more programs for myself, but it's so time consuming. It would be great if I could see all the values in the stack and in memory locations at all times, see code changes and their results instantly, and have keystrokes recorded automatically so I didn't have to stop and write, or erase and rewrite, them. Am I dreaming?

Edited: 5 Nov 2012, 9:26 p.m.


Short answer: yes, long answer: yes, there is. Well, at least, there once was such a thing, showing the stack and some registers. It was programmable using commands like the HP41 and was a nice toy to watch computing, moving X to LastX, droping the stack, etc.

It must be somewhere on my elder disks, I will look for it.



RPNdemo from John Kennedy is an emulator in an other sense as all others here. From the manual: RPNDEMO is NOT intended to be an HP-41 simulator, but where possible the instruction set matches that of the HP-41 exactly. With few exceptions RPNDEMO includes most of the programming capabilities of the HP-41. This DOS program shows an animated view of the stack movements during operation. So it may help you to explain RPN to a novice or for testing stack usage for a routine fragment. To see the animation on fast PCs you need to call it from a slow-down.BAT:

SLOW -f1 50000 -f2 30000>nul

Alas the links to TP7P5FIX ( and SLOW ( are broken, hope you find new ones. The first is a 'Fix for "Runtime Error 200" bug of Borland Pascal 7 on fast PCs' and the second is just a slow-down tool for old DOS programs if you like to watch the animation.



Thanks a lot, Mike. I appreciate it!


Glad you like it. Could you please tell me where you found the necessary fix and slowdown routine?



Well... I was actually thanking you for your reply and the info you shared. I'm sorry to say that I didn't actually try it. I don't know a whole lot about those kinds of things, so I was hoping for more of a ready-to-go emulator.


Well, I did not read your question carefully:

Does anyone know of a free RPN stack emulator for the HP 35s?

I know only emulators of RPN calculators for DOS, Windows, Unix, iOS, ... - :)


Possibly Related Threads...
Thread Author Replies Views Last Post
  HP50g: Writing a function that returns a function Chris de Castro 2 590 12-10-2013, 06:49 PM
Last Post: Han
  Writing RPL programs on OS X Sean Freeman 18 1,607 11-30-2013, 03:59 PM
Last Post: Sean Freeman
  [OT] Mathematica free for Raspberry PI BruceH 32 2,576 11-23-2013, 05:24 AM
Last Post: Nick_S
  Simple Tetris. free for you to improve on cyrille de Brébisson 3 557 11-20-2013, 05:43 PM
Last Post: Erwin Ried
  HP 50g - select characters on the stack, copy/paste Sean Freeman 7 836 11-20-2013, 07:11 AM
Last Post: Sean Freeman
  Prime: Placing more than 1 item on the RPN stack in a single program? John Colvin 4 628 11-19-2013, 08:59 AM
Last Post: Miguel Toro
  emu48 - copy stack doesn't work (as expected) Thomas Radtke 2 622 11-11-2013, 02:19 PM
Last Post: Thomas Radtke
  HP Prime Stack operations from within a program John Colvin 1 443 11-08-2013, 09:45 PM
Last Post: Helge Gabert
  [PRIME] RPN: another attempt at returning more than one value to the RPN stack Marcus von Cube, Germany 5 768 11-05-2013, 02:44 AM
Last Post: Marcus von Cube, Germany
  [HP-Prime] - Shortcuts for program writing Jean-Michel 4 611 11-01-2013, 07:55 AM
Last Post: Jean-Michel

Forum Jump: