HP-41 FOCAL to .ROM for Clonix/NoV's (or any other ROM-box)


Hi all,

Since the Clonix module was released many users have tried to get their (or others') FOCAL programs converted into a .ROM image file. I still receive mail asking for such a solution.

Some detailed procedures have been described and eventually, with the appropriate hardware, several users have managed to have their own .ROM file gathering FOCAL programs of their own or available elsewhere.

Many FOCAL programs are available in .RAW format, but the process described below is usefull regardless the way you get the FOCAL program into MAIN memory.

Let's say that I'm not the one to credit about this all. I just find the pieces and put them together. Credits goes to Warren Furlow's for his V41 emulator and companion software.

The Pieces:

- V41 windows emulator. You'll find the link in this very site.


Go to "Free Simulations at other sites:", the fourth line leads you to the appropriate place.

- The .MOD file for the HEPAX module (included in V41 "MOD" directory)

- The ModFile.exe (or ModFileWin.exe) utility. Also available in V41's site.

- The .RAW files you want to include in your .ROM image. AND/OR patience enough to key in your own FOCAL program into V41... :-)


Dowload and install V41 (in case you haven't done yet)

Run V41 and go to edit configuration to include HEPAX.MOD.

Please note that V41 will start as 41CX. It is recommended to use 41CV instead to avoid HEPAX emulation failure. If you "really" need 41CX mode in V41 then you'll (also) "need" 82143A.MOD printer loaded, in order to push HEPAX to page #7.

If HEPAX is not loaded into an odd page it will run at first instance but will refuse to start-up after power cycling. This is not a malfunction of the V41 emulator, it's just that HEPAX has its own instructions and V41 emulates just the HP-41, not the module itself.

Once V41 is running with HEPAX:

- Load as many .RAW program files as you want/can (or type them) into main memory.

- Use HEPAX "HSAVEP" to compile the FOCAL program(s) and move it into HEPAX RAM. (See HEPAX manual for details on HSAVEP command.)

- Once you've saved a program into HEPAX RAM you can clear it from MAIN memory using CLP command.

- Repeat the steps above as needed to get your HEPAX RAM page(s) loaded with the program(s) you want. There are two RAM pages in HEPAX.MOD emulation. (8K in total)

- Once finished you may want to run HEXEDIT to modify H'8000 and/or H'9000, these are the XROM # of the .ROM(s), in order to avoid conflicts with other known XROM numbers.

- Turn OFF (close) V41.

- Execute MODfile.exe (or MODfileWin.exe) and extract .ROM files from HEPAX.MOD.

- You'll get 4 HEPAX??n.ROM files (we don't need these) and two HPX-STD-RAM1.ROM and HPX-STD-RAM2.ROM. Yes!, these are the files we've been doing it all for... ;-)) If your program(s) fits in 4K, only RAM1 file is needed.

- Rename these files at your convenience. If you're about to use them with Clonix/NoV's use 8.3 naming convention, and place them in the Clonix/Nov working directory.

That's all folks. All in a row, no extra hardware required, plain and clear.

Hope you find it useful.

Cheers from the Canary Islands



Hi, Diego;

and thanks! This is enlightening in any way, even when the user has done this before. I have once done that a few years ago, when I had the hardware to do it, but the way you post about it eases the procedure.

Just a question/suggestion: isn't it worth an article? 8^)

Cheers and thanks again!


Hi Luiz,

I was pretty sure that some other users must as well have gone this path, but haven't found it detailed, so I decided to post.

I'll gladly put it into the Articles forum if it deserves general interest. A better text formatting will be required though.

Thanks for your kind words and best wishes.




a little while ago I posted an article which allows the very same thing, using different means. It also helps in case users want to mix and match Focal and MCODE programs in the ROM.

You can find the article here




Hi Peter,

Good to read from you... :-)

I do know your article. Just think this is intended for a different user target.

My notes are mostly aimed to de "average" user. No M-code, no MS-DOS PC to run EMU-41, or SDK-41... just wanting a few FOCAL programs into a .ROM file, the easiest possible way.

(Still don't know if I hit my target though...;-)

BTW, I'll mail you in short regarding those VASM listings.

Meanwhile, best of lucks from Spain.



If I may chime in here...

This is a slippery subject. Diego's procedure is easy enough to be successfully used by casual users without a deep understanding of the intricacies involved.

I currently use the MLDL2k to download the HEPAX ram ROM files (either from V41 or the real mlife machine,, that's the beauty of it). To edit them (subtleties like converting XEQ to XROM, FAT changes, MCODE additions, etc) is possible using the disassembler (also part of MLDL2k software). But this is a tad too much for "casual users" - assuming they exist :)



And for the i41CX users: my next version of M2kM supports extraction (and thus disassembly) of emailed .MOD files or HEPAX RAM files ...


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