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Full Version: AECROM in NoV-64d and i41CX
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this my first post ever, so i will try my best. I am a new owner of a NoV-64d modul and have made two experience, that I like to share.

First on my Windows 10 Pro 64 bit PC the programmer don't work with a long USB-cable plug into a blue USB-3.1-Port. The steps
- Programming ROM
- Progragmming EPROM
- Verify ROM
are working.
Next I see "Error..." and a Messagebox with "The board is not responding…". Plugged into the HP-41CX, the NoV-64d was invisible then.

It works well with a short USB cable on a black USB 2.0 port.

Second I programm a AECROM into the NoV-64d and make COPYROM to page 10 and 11. The part with the unit-conversen works very well. I can switch the mode with holding down the ON-key. No Problem so far.
Then I try to use the PROG-command. I can Input the Programname and the Formular. After R/S the HP-41CX go off suddenly. The very same is happen with my iPhone App i41CX with HEPAX in Port1 and the AECROM in any other port.

A workaround is to connect a HP 82143A Printer. Then the HP-41CX don't go off after the R/S and I can "ENTER:LBL,CONS.". Again it is the same with the real HP-41CX and the i41CX App, where a Printer is build in and can be disabled.

Without HEPAX in Port1 there is no Problem with the AECROM in the App.

Best Regards
Hi Klaus,

And welcome to the forum and our HP-41 enthusiasts community.

I'm curious about this AECROM/HEPAX (or NoV for that matter) interaction.

Do you have a 41C or CV to test if it also behaves the same?


Hi Diego,
I don‘t have a real 41C or CV. The app i41CX have a CV-mode. In this it all works fine, the calculator don‘t switch off by itself.
When a Printer is connected and on in MAN-mode, then the formular is print. This happen in real and in the app. I think it is this try to print after entering the formular that make the problem. I can not understand the reason why the aecrom print the formular and nothing else when I use the PROG-command.

Your NoV-64d is fantastic, I love it and can use ROMs now, that I only can dream of before.

Best Regards
now I could plug the NoV-64D into an HP-41CV and try out how the PROG command of the AECROM behaves. The problem described above does not arise. The PROG command behaves exactly as described in the manual. So there is only an effect with the combination HP-41CX + HEPAX + AECROM: Then the PROG command does not run without a printer.
Best Regards
Hi Klaus,

From your comments about the behaviour when plugged into 41C/CV my best guess is that HEPAX code (self)allocated in page #6 is conflicting with AECROM as it expect to find either a PRINTER or "nothing" in that page.

Since HEPAX (self)allocates in page #5 when plugged into a C/CV this conflict does not arise.

Also if you plug a printer on your CX, HEPAX will re-allocate into page #7 and the problem won't show up either.

Hope this clarifies the point.

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