"Wer einen anderen nachahmt, erkennt dessen Überlegenheit an."
Ralph Boller (a swiss author)
About: Who imitates someone else appreciates his superiority.

You may click on items in site map above

First things first:

1. All statements here imply AFAIK. Judge the value on your own. Read the legal stuff.
2. The "retro" design of this site is pure intention to make it viewable on small systems like Palmtops and alikes.
3. Site updated 7/16/05 (m/d/y): »My list« of emulators, an HP-12C photo-skin for Nonpareil, my first HP-12C program, Voyagers on VM/ESA now with help files, and few HP41 routines.

What?

NutEm is written in machine independent FORTRAN, but at present there is only an interface to fullscreen CMS on VM/ESA (an OS for IBM main frames). You may download NutEm for Voyagers.
 

How?

• screen shot of NutEm (~14k)

• screen shot of NutEm with some trace output shown (~29k)

Why?

• analyse the logic of your routines and re-code them in a programming language available on your new computer. That's ok if you have only a few simple routines to migrate.

• write an interpreter of your old tool's programming language. Advantage: no need to analyse your old routines as they run unchanged in the new environment. Disadvantage: you have to write a program for every command you use in your old routines. On the HP-41 there are about 120 built-in commands and every plug-in module may contain up to 128 more. Those commands may be quite complex and you must rebuild them as close as possible to the behaviour on the original device. (The owners of a HP82210A HP41CV Emulator Application Card for the HP48SX who used synthetics or Extended Function in their programs know what I am talking about.)

• you may logically emulate (or simulate) the CPU of your old machine and interpret it's firmware (OS and plug-in modules). It is the same idea like the previous, but 'a level deeper' and much simpler as only the instruction set of the CPU has to be programmed. There are only a limited number of instructions and most of them are very simple to rebuild. Advantage: If all CPU-instructions work correctly, your programs will give exactly the same results as on the original machine. In addition, you are not restricted to routines in user language, for example the 12k ADVANTAGE module works in such an emulator in the same manner as on the HP-41.

For more information about Hewlett-Packard pocket calculator HP-41 click here (the best RPN pocket calculator I know).

Are results exactly the same?

For a long time I believed, such an emulator could be error free. Until that day when in the emulator the Service Module displayed <<CPU OK>> but the Time Module function DOW insisted on 1/1/1900 to be a Sunday. I know it was a Monday. Darn! Emulated CPU tested ok but still computing wrong. (I do not start a monologue on the value of self-tests here.)

As results are the same, the handling is not. I was not able yet to implement the keyboard and peripherals (printer graphics, HP-IL) in a manner adequate to the emulation of the CPU. So the printer is simulated, it writes lines to a window with 'logfile on' to get a copy to disk. Moreover, the legendary tactile feeling of the HP-41's keyboard can not be emulated, simulated, or copied.
 

So what?

1. there are too few who have access to VM/ESA and do need an emulated HP-41 on it,
2. the user interface of NutEm sucks if you compare with V41.

And now?

More...

The interface from the kernel (Coconut) of NutEm to the real world (VM/ESA) <G> is done with CMS Pipelines. However, I should re-code NutEm as Co-Pipe (suppose it will stay unfinished).

There are several emulators and simulations of the HP-41 around. The most complete one is from J. F. Garnier, emu41 and it runs on DOS. For two or three bugs hard to find I was happy about the excellent tracing possibility of emu41. You have no access to an IBM host with VM/ESA? Then JF Garnier's emu41 is the first choice if you prefer DOS programs. If you like Windows then try the Virtual HP-41 from Warren Furlow. You will be overwhelmed. See his link page too. An other one for Windows is HP41e from Hrast Programmer. However, he regards it only as "secondary". His main oeuvre is a HP-41 emulator for the HP-48G/GX (and S/SX if I remember well, see HP48 Software Archive). HP's solution for the HP-48SX was a simulator (HP82210A).

Do you prefer other platforms? Bernd Abel offers a nice solution for Coconut PalmOS. For the same OS is Charles Lee's P41CV -- Palm OS HP-41CV Emulator. And those who like WinCE may try eV41 from Frank Bauernoeppel. Once again back to DOS: Alvaro Gerardo Suárez offers a SIM41, but it seems to me to be a simulation not an emulator of the HP-41. At least, his site is worth to visit. If you are on Linux then try Nonpareil from Eric Smith. Since version 0.77 he published a Windows variation of his masterpiece that »simulates« almost all classic HP calculators.
 

What else?

• a list of emulators I know,

• my Hewlett-Packard calculator collection,

• and some aspects of me, myself, and I.

Legal stuff

• All disclaimers claimed.
• Any information here is provided as is. If something's wrong, you are on your own.
• All my statements imply AFAIK (=as far as I know). Consider, in case of error it may be just your point of view :-).
  BTW, the so-called exact sciences (physics, chemistry, biology, and mathematics [not medicine!]) once had been part of philosophy (Phil.-II). Serious scientists are aware of this fact and regard "truth" as a term used only by lawyers and popes.
• My software offered on any page of my site is published under the Q Public License V1.0. Please read and proceed only if you do aggree. (SW on outside sites may be published under other terms.)
• Some of the above given links point to sites outside my responsibility. They may change without notification. If they show something illegal, do not reproach me for that.
• For more information about me as the responsible see here.