HP Forums

Full Version: 41C Memory Module 82106A Check / Test
You're currently viewing a stripped down version of our content. View the full version with proper formatting.

Hi again fellows,

I´d like to check / test an HP-82106A Memory Module for failure. Does exist a program, embedded function or standard procedure available and useful? I suspect a malfunctioning behavior, unfortunately. Many thanks!

BTW, the Card Reader / Writer was successfully repaired and it works great after almost 26 years of inactivity. HP quality is amazing! The gummy wheel was replaced by a medical silicone tubing: it fits and works perfect! "Gracias" a lot Karl-Ludwig Butte.


If I am not mistaken, the service module can test the memory module. You will need either the real module (not common), or have an image of it loaded in some ROM emulation device.

The memory module loads itself in upper memory and becomes data memory by default, you can resize if you want to. I do not remember how many registers you should have (each module adds 64 registers), but if you find out, you can always write an RPN program put various numbers in it and see that they are recalled properly. Unfortunately, it is not easy to test with arbitrary bit patterns this way.


If you're handy with a solder iron, I'll gladly send you the internal circuit of the 82106A module so you can replace the defective one.

Let me know if you're interested.

Best regards.


Hi Diego,

Nice! I've got some skills regarding electronics. I accept your proposal, it sounds a challenge. Thanks in advance!



Please mail me with your shipping address.

Regrettably I will take several weeks to send it because I'm not at home, but'll have it for sure :-)



I sent you an e-mail; I'm ready to start. Thanks again,


Fine, you've got mail too.