When did all this started?

In the year 1998, after I decided to write an HP-41C emulator for my HP-48G+, not something like HP-41CV Emulator Card for HP-48SX, but true emulator which will execute HP-41 microcode, support synthetic programming and behave like the real thing. At first, I developed HP-41 emulator for Windows which main purpose was to be used as a development and testing platform for HP-41E, HP-41X and HP-1XE. Then, in 1999, I developed HP-41E emulator for HP-S/SX/G/G+/GX and HP-49G. During the 2000 and 2001, I developed HP-41X with a totally new and unique engine which was later used in HP-42X and HP-71X. HP-42X emulator was developed in 2002 and HP-71X in 2003. HP-IL emulation for HP-41X and HP-71X was developed in 2004. During the year 2005, I managed to get the HP-11C/12C/15C/16C ROMs so the development of HP-1XE was possible (although, technically speaking, the HP-1XE engine was developed during the year 2000).

Why arenít your emulators free?

Some of them are free: HP-41E (for HP-48S/SX/G/G+/GX and HP-49G), TI-57E (for HP-48S/SX/G/G+/GX and HP-49G) and TI-95E (for Windows). So, no one can say that I donít give anything for free. I spent too much time and money on development and I don't see a single reason to give the other emulators (HP-41X + HP-IL, HP-42X, HP-71X + HP-IL, HP-1XE, various printer emulators) for free.

Are there any other way for obtaining them?

Not anymore. Many users obtained emulators in exchange for various literature, ROMs and similar things and I was always very generous regarding the exchange. But now I have everything I need so the only way to obtain the emulators is to purchase them.

Why did you abandoned development for Windows?

The main reason is because I love programming calculators, period. HP-48GX is my essential emulator/hobby development platform for years, mainly for programming in Saturn machine language, as well as User/System RPL. The second reason is that running emulators on the real calculator is much more useful and flexible (and fun, too). The third (relatively unimportant) reason is that other emulators for PC exist, like V41, and despite the fact that my HP41EPC was more advanced in many areas (assembler, disassembler, debugger, tracer, card reader emulation, printer and timer emulation before V41, etc, etc.), I don't see the need to compete with them.

What about HP-49G+ and HP-50G?

There exist HP-49G+/50G versions of all my emulators but I don't state this explicitly on all places where appropriate because I don't have time to go through all pages and add this info. You can safely assume that every reference to 'HP-49G' actually means 'HP-49G and HP-49G+/50G' (with limitations described here, of course).

Why arenít you on MoHPC forum anymore?

Well, I was absent for a few years because I shifted focus to my Electronic Music and Digital Signal Processing projects. I returned after developing my TI-59E emulator and SATURN BASIC programming language/environment. But it's a different forum now, with different people, different interests (which I am not interested in at all) and different atmosphere. I cannot explain why exactly, but I didn't feel particularly good there anymore. So, I don't participate regularly although I scan the forum from time to time and jump in if I find something interesting ...

What real calculators do you have?

(*) HP-48GX #1 (with 128K & 2048K RAM cards)
(*) HP-48GX #2 (with 128K & 2048K RAM cards)
(*) HP-48GX #3 (with 128K & 2048K RAM cards)
(*) HP-48GX #4 (with 2x128K RAM cards)
(*) HP-48G (expanded internally to 768K)
(*) HP-50G #1 (with 2GB SD card)
(*) HP-50G #2 (with 2GB SD card)
(*) HP-50G #3 (with 2GB SD card)
(*) HP-50G #4 (with 2GB SD card)
(*) HP-49G #1
(*) HP-49G #2
(*) HP-48G+ (damaged keyboard)
(*) HP-49G+ (crappy keyboard)
(*) HP-48SX
(*) Sharp PC-1403
(*) Sharp PC-1251
(*) TI-59
(*) TI-57

How can I have all emulators installed on the same machine?

Installing all of them on a single HP-49G (not to speak about HP-49G+/50G) is too complicated (if not impossible, for various reasons and hardware/software design flaws made by HP/ACO/Kinpo) but the situation with HP-48GX (equipped with RAM cards, of course) is perfect. You just need some utilities for port management and you can have excellent multiple-emulator environment on a single HP-48GX. These utilities are free of charge for registered users. Details and instructions are inside the package.

Can I print from HP-49G to the HP-82240A/B IR printer?

Yes, you can, with a little help of HP-48 running my RED48 program. You can connect HP-49G and HP-48 with serial cable, run RED48 on HP-48 and start printing from HP-49G. RED48 will capture the output from HP-49G and send it to the IR printer at the same time. RED48 is free of charge for registered users of HP-41X/42X/71X. Details and instructions are inside the package.

Why isn't 'MEMORY LOST' possible with HP-41X running on HP-49G?

It is possible but with a little trick. On HP-48GX, you can press <− and ON keys together with the calculator switched off, then release ON (this will turn HP-48GX on), release <− and you'll get 'MEMORY LOST'. The operating system on HP-49G is different (don't ask me why) and you must release all keys before the calculator will turn on. To get 'MEMORY LOST' on HP-49G you must press and release the ON key, then immediately (very fast) press <− key and release it.

The same situation is with ON&key combinations on HP-11E, HP-12E, HP-15E/X, HP-16E and TI-57E emulators (except ON&C and ON&D which are not available when the calculator is turned off).

Why do you use dot-matrix 5x7 font with HP-41X?

Because the original HP-41C font is very ugly to my eyes. It is OK for digits but it is not really suitable for the whole alphanumeric character set (not to speak about special characters). I believe that HP had a lot of technical/financial reasons to use such display in HP-41C and if dot-matrix 5x7 12-characters LCD would have been available (and affordable) at that time they would have used this type of LCD instead of that ugly "LED looking" one.

Which calculators are emulated (directly and indirectly)?

Directly: NUT/SATURN based RPN/BASIC programmable calculators with LCD and ENTER/ENDLINE key.

Directly & indirectly: Here is the list of calculators and emulators which I use when I need some particular calculator:












 (HP-11E), (HP-15E/X), [HP-41X]


 [HP-11E], [HP-15E/X], [HP-41X]




 [HP-11E], [HP-15E/X], [HP-41X]






 [HP-11E], [HP-15E/X], [HP-41X]


 [HP-11E], [HP-15E/X], [HP-41X]


 [HP-11E], [HP-15E/X], [HP-41X]




 [HP-11E], [HP-15E/X], [HP-41X]


 [HP-15E/X], [HP-41X]


 [HP-11E], [HP-15E/X], [HP-41X]










 [HP-11E], [HP-15E/X], [HP-41X]


 (HP-11E), (HP-15E/X), [HP-41X]


 [HP-11E], [HP-15E/X], [HP-41X]














 (HP-11E), (HP-15E/X), [HP-41X]


 (HP-11E), (HP-15E/X), [HP-41X]


 [HP-11E], [HP-15E/X], [HP-41X]





[]: Use instead
(): Use instead (without printing)

Note that (except HP-71B) all calculators use RPN logic because I don't like the way algebraic mode is implemented on HP-17B, HP-27S and similar calculators. When I need algebraic mode, I use HP-71X because its CALC mode is excellent. I have HP-17B and HP-27S ROMs and I already disassembled them so I know how to develop HP-17B and HP-27S emulators but I won't make them because I really don't need them.

Why do you use the term 'emulator' and not 'simulator'?

Because this term is widely (and for a long time) used to describe such software, not only with calculators but also with computers, game consoles, software synthesizers, etc, etc. Even IBM, who invented 'emulation', agree about that:

(*) Emulation:

The use of software, hardware, or both by one system to imitate another system. The imitating system accepts the same data, runs the same programs, and achieves the same results as the imitated system.

(*) Emulation program:

A control program that permits functions written for one system or device to be run on another system or device.

(See http://www-306.ibm.com/software/globalization/terminology/e.html#x2026723)

Why do you use the term 'microcode'?

Because (the good old) HP used it everywhere to describe the machine language of their calculators. I strongly believe that HP programmers knew very well what they were doing when calling it 'microcode'.

What are these ADQEE and ADQUE codenames of HP41X and HP41Z libraries?

Believe it or not, this has something to do with the interrupts. There is no further explanation as this belongs to the inner working of the emulators.

Why did you remove a logo from the latest releases?

Because it saved a few valuable bytes. I only left the emulator signature in the upper right corner of the display (so you know at any moment which emulator is currently running).

Why did you remove ON&key "chirp" from the latest releases?

Because it is a little annoying, especially in quiet rooms. Chirp wasn't possible with HP-42X and HP-71X, anyway, so now all my emulators are behaving uniformly.

Can you teach me how to use/program a HP-XYZ calculator?

No. I am a software developer. I can help you with the installation of my emulators (after you studied my installation instructions and tried everything to do the installation by yourself, of course) but I cannot teach you anything else about HP-48GX, HP-49G, HP-49G+, HP-50G or any other calculator.

What about releasing your emulators as open-source?

Yes, what about it? From time to time, I receive a request to release them as open-source. Sometimes it sounds like I SHOULD DO THIS because it is to be expected. Well, I SHOULD do only what I WANT to do. And I DON'T WANT to release anything as open-source because I have no reason to do this. Except in a few rare cases, I don't like this open-source concept at all so I will not participate. All my emulators will be closed-source forever. Don't waste your and my time asking such questions.

Why aren't FORTH and PANAME modules included with HP-41X?

Because I was asked to remove them. Long time ago, I asked Jean-Daniel Dodin for a permission to distribute a FORTH module (downloadable from his site at that time) together with HP-41E and he gave me the permission. Later someone (I don't remember who) complained about it and I removed this module (although I had a permission to distribute it). I received the similar complaint about PANAME so I removed it, too. Now I see that PANAME is freely downloadable from www.hp41.org but my policy is not to bother with something I was asked to remove in the past. Nor FORTH nor PANAME are compatible with HP-41X, anyway. FORTH uses pages 4 and 5 which are already occupied and PANAME has XROM number 9 so it clashes with CCD ROM.