MLDL2000: ROM images and the like


Hi MLDL2K owners, all;

I want to know who of you is/are interested on sharing experiences, ROM images and related stuff about the HP41. I myself have only a few ROM modules and peripherals, most of them are already available to be downloaded form other places. Anyway, I have two different card reader versions (F and G), one of them (F) with the weird bug when keying in parameters and using correction key (maybe it is due to hardware instead of software, who knows). I also have an Extended IO module that, surprisingly, returns BAD after ROMCHK. The others are X-Functions (don't remember version), Financial 1C and Navigation 1B. And we can count on the existing ROM of my 82143A peripheral printer, Wand (82153), HPIL and IR Printer Module 82242A.

I want to go ahead with MCODE programming, too.

Maybe some guys think it is some sort of time wasting when dealing with such past-due technology, but what calls my attention to the HP41 is that high-tech, current technology seems to be too close to it that it seems the HP41 is up-to-date technology as well. Seeing Meindert´s boards connected to the HP41 ports and working so tuned with it makes me wonder about what the HP41 represented in its time.

Please, anyone that actually wants to share experiences, I'm 'all ears'. I have never programmed in HP41 MCODE before, and I am yet studying, so I have too much more to read and listen than to talk, but I'd like very much to share whatever I achieve as well.

In time: should MLDL2000 related discussions be posted here with others? Although it agrees with the MoHPC Terms of Use and is related to old HP calculators, I prefer having it as consensual use of the forum space than to have the feeling of being an invader. Just my own thoughts, though.

Best regards and thanks.

Luiz (Brazil) - lcvieira (at) quantica (dot) com (dot) br


I would like to continue using this forum for any discussions about mcode and the MLDL2000/Clonix/NoVRAM. This is the favourite hangout for most who have experience with these, and also those who do not have the hardware can offer comments. The alternative is to create a (Google) Group or maillist, but I really prefer to have one place for all HP related talk: this forum!



Hi Luiz!

I'd really like to keep the MLDL & Clonix/Novram discussions in this forum!

After all, we're not so numerous to constitute a real nuisance to other users and, for myself, I've learned a lot on the Hp-41C innards even before owning one of these devices!

Maybe, we should check with Dave Hicks that talking about the Rom images doesn't go against his forum/site policy.

I fully intend to respect his options because we're hosted here - even if I've tried to bypass them from time to time...

BTW, thanks for your mail and sorry for not responding yet :-)

Friendly regards from France!



Hi Luiz, all...

I'd also prefer a common "meeting point" to discuss about our beloved machines/accesories.

Obviously, it's Dave's last word what really matters as all of you have already stated, and I'll also accept whichever decision he adopts.

Copyright issues have been dicusssed over the time (and will surely be in the future) but I don't think our new devices/modules by themselves make any difference with previous ROM/RAM-Boxes or ZEPROM, CMT, HEPAX... modules. Just new technology and more memory but same functional principles.




Hi Meindert, Etienne, Diego, guys;

I thank you for your comemnts and thoughts. I was just in the need to read(hear) from others, because I`d like that anyone interested on knowing/sharing information about the HP41 new tools from you, guys, could find the MoHPC as the place to do so. And I prefer it as well.

About updates and the like: I read some news from Diego's NoVRAM and have already downloaded the updates. I also visit Meindert's whenever I have the time to. Should we, users, consider these as the references for updates so far? Also, I see that some updating data is available through TOS, and they are somehow related to your modules' primary activities.

Are there any other places to search for news?

Best regards.

Luiz (Brazil)


hi all

i'm a fairly regular lurker here (1 or 2 times/week) and would think it would be an obvious place to share experiences, thoughts etc.

chic :MLDL 2074

(status : basic testing done, just trying to pucker up the courage to take a dremel to the cardreader shell! just doesn't seem right somehow!)


Hi, Chic (AKA 2074... 8^)

Please, have a look at the pictures here (maybe you have probably already seen). Some of them show only the PCB's and connections, others show the cuts. Some are new, added now, and show what I used to cut the upper square little hole.

Hope you find encouragement in these images. Afterall, if by any reason you decide ti use the car reader holder, filling the holes back will be easiear than making them up...

Best regards.



Back in the days there was a form of snobbery by which you "needed" the smallest possible registration number to the various clubs to prove your early commitment and the fact that you were an "old hat" not easily disproven by young fellows. I wonder if there is such a trend here ? GE /2064/
Only kidding !


No offence taken, You still see people rolling off all their serial Nos in sigs too!

I hadn't seen Luiz's pics before, they show a level of care and attention to detail that is wonderful, a real inspiration to be patient, thoughtful and get this construction right, as befits
the work that has already gone into the whole MLDL project.

I'll report back when i get some progress

Chic (2074 still in bits!)


I added the pictures with the very intention of showing that you can go further. Meindert himself encourages this sort of inspired modifications, even if you want to use a different case.

BTW, GE, I was not known about the common hierararchy (snobbery?) related to the early, smallest numbers... although I agree with the fact that it makes some sense. And yes, I am following the spirit of the 'Only kidding!' as well, so, please, just read this for fun, O.K.? I had no intention at all, mainly when I think that the first unit belongs probably to Meindert and the others close to it are the ones used by the brave Beta-testers. As I am ordering another unit (once you get to it, you can't live without it...), this new one will surely have a bigger serial#, so I can even make a choice... d8^D

Best regards and thanks for your kind words, guys. I appreciate.

I still miss the other MLDL2000 owners and their related paritcipation and experience sharing (just know who are a few of them). This module is a dream come true, at least for me...

Luiz (Brazil)

Edited: 16 Nov 2005, 11:07 p.m.


About the serial numbers and a bit of history:

There are four units designated as Beta units (#B2001 to #B2004). Two are with myself (one unit for daily use and one working unit on a breadboard for testing). One of the beta's is in the field with a user and number four is damaged after unsoldering the FLASH memory chip.

The regular units start with serial number #2001 (someone is very happy to have this lowest serial number!). All units with serials below #2050 have double capacity SRAM, these have been assigned based on order date. The 2* SRAM is there because at production time there was a shortage in the original size SRAM chips, and I was offered 2* the size at the same cost, so about half the units have 2* SRAM. This capacity is currently not being used nor supported (but it is tested), and for possible future support a handsoldered wire connects the A19 line (which is not connected on the 1* SRAM chips).

Serial numbers >= 2050 have 'just' 512K*16 bits SRAM chips.

The serial number is programmed in the EEPROM on the USB interface, and allows the M2kM software to recognize the unit and show the serial number.

Personally I do not really care aboutserial numbers, since I am a user, nota collector. However, I do care about the kind words you have for the MLDL2000, thanks for that.



I still miss the other MLDL2000 owners and their related participation and experience sharing (just know who are a few of them).

That sounds like a request for lurkers to reveal themselves...

I feel very fortunate to have an MLDL2000 too (some very high serial number, I'm sure :-), but my experience so far is only to gaze at the pieces in amazement.

I ordered the USB connector just today, but I don't know when I will have the nerve and patience to start the assembly.

Once it is assembled, I will be of little assistance to others as I am an mcode novice and don't have a lot of time to spend with it, but I do share the enthusiasm.

I am certainly paying close attention to the MLDL2000 threads, so please keep up the reports so I may learn! (Great pictures too!)

Thanks again Meindert!

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