How to dump your own ROM on a 41CX


Hi all,
me again. I got the hpil-pc board working on a PII (thanks Raymond, Emmanuel, Chris and others), now its time to put my rom to good use on the emulator.
But how I could copy my own rom?
I have HPIL DEVROM and EXT I/O rom that I would love to emulate and also I don't have a CX rom image (but I have the calculator).
Is there a program that I could download to the calculator and it will give me the dump of the roms? I don't have PPC,CCD,Zenrom and the like.

Thanks in advance,

Giuseppe Marullo


You need a special module in order to disassemble your ROM.
Zenrom and Hepax make that.
PS I know that you have a 41CX, thus I sent you the necessary files. ;o)


many thanks.
I don't see the files, I suppose you got the same problem (mailbox full).
Please use my private email: giuseppe at marullo dot it.

So it is not possible to download ML code if you don't already have said modules?
No way? I can't believe it...


I have somewhere (but where?) a program that disassembles ROM without additional module.
Let you know when I find it. ;o)


I got the files and EMU41 runs with a CX core now!
I hope J-F will unlock my copy asap, I really want to try the hpil thru EMU41.

I remember Diego telling that is it possible to dump a module using an easy connection between a couple of pins and the parallel port. A program is surely a better way(safer!), but just in case...


Hi Giuseppe,

Many ROM images are available on a 'well-known' HP-41 site, and new Emu41 version (to be available end of January) will be directly compatible with .rom format (at the moment, you have to use the clbin41 conversion tool)...



Hi all, Guiseppe,

Yes, it's possible, I've done it four or five times successfully and it's not dangerous in any way... (ROM PAC -> PC parallel port dump, I mean ;-)

No risk is assumed, both your ROM PAC and your PC are always at a safe working zone.

Anyhow, the range of PC parallel interfaces working voltages are so wide that only three out of seven tested machines handled the process without errors, a single chip (or may be a single transistor) will solve the trouble, as it's located only in the ISA line INPUT/OUTPUT separation, but I've been quite busy these days, and assumed that this "micro-project" of mine was of little or no interest to most users. Actually most ROM images are (as J-F has pointed out) at a "well know" place.

If your're interested please mail me, I'll gladly send you the schematics and the dumping utility.

Cheers from the Canaries.


P.S. For the sake of precision, this procedure DOES NOT work with Clonix modules, only with original ROM PAC's.

Edited: 13 Jan 2004, 7:46 a.m.

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