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I got to ask I just recieved in the mail a HP82106A memory modual, and reading the HP Advance programming guide it mentions not using it on a HP-41CV, any reason for that?


The HP-41CV and HP-41CX already contain the maximum amount of normal memory, so it is not possible to use the 82106A memory module or 82170A quad memory module with them. These modules should only be used in an HP-41C (no "V" or "X" suffix). Installing these modules in an HP-41CV or HP-41CX will not add usable memory, and may result in system crashes, higher battery drain, or other problems.

Similarly, the 82170A should never be used in combination with any 82106A modules.

Adding a 82106A memory module or 82170A quad memory module to a HP-41CV or HP-41CX will not increase the memory in those models, because they already contain the maximum 319 addressable registers of internal memory. A HP-41C is the only model that can benefit, as its internal memory contains only 63 registers. A 82106A module will add 64 registers and a 82170A quad module will add 256 registers to an HP-41C. You can expand an HP-41C to 319 registers by adding 4 82106A modules or 1 82170A module. If you do install one of these modules in an HP-41CV or HP-41CX it will not function properly and the calculator will lock up if you attempt certain memory operations.

Edited: 19 Feb 2010, 9:38 p.m.

Thank you two for that, I have removed the module mind you still reading have not tried any memory functions with it thankfully. I guess it means I should have read up more. Mind you I ordered it before getting the calculator in the mail. Shame 33$ off ebay and not useful as a paper weight. Guess it will go into the parts box.


Shame 33$ off ebay and not useful as a paper weight.
I have a CX which can't use them, but I intentionally got a couple anyway (although maybe only about $10 each) for the possibility of building something else into them at a later date, like NoVRAM.

I have removed the (82160A memory module from an HP-41CV) ... Shame 33$ off ebay and not useful as a paper weight. Guess it will go into the parts box.

I'd keep it in case you decide to acquire an HP-41C to complete an HP-41 collection: C, CV, CX. "Fullnut" models (1979-84/85) have nicer, more-legible displays, and the earliest models of these (e.g., C and CV from 1979-80) have shorter, but bolder, display segments.

The first-year HP-41C is of the steep-edged "tall keys" design carried forward from LED-display models that immediately preceded it. The later key design was better, but the original has some collector value...

-- KS

Edited: 20 Feb 2010, 1:26 a.m.

Interesting. I wonder if there are any in HP production technical specs available to produce new cards like that. Maybe the DVDs will have some data I can use for that end.


Thank you for the reply. I do have somewhat of a similar goal but not to collect the calculators but accessories to use.

Double ended sword. I want to learn to use the HP-41 as well as I can but I also want to reverse the process as I am back in college and have a couple 4 month summers to get it done. Get a updated modern version of the HP-41 with SD cards for program storage and a HP-41 type slot to use original accessories with the HP-IL system. The memory expansion will not work in the slot, since there is the SD slot will hold program files. As will a ROM chip inside will hold many application packs built in.


Edited: 21 Feb 2010, 1:01 p.m.