HP-41C double memory module?

[Dieter]

I think most HP-41 users are familiar with the Standard RAM module 82106A (64 registers) and the Quad-RAM 82170A (256 registers) that appeared a bit later.

Now I seem to remember that there also was a Double RAM module with 128 registers. No, not the X-Memory module, but something between the mentioned single and quad capacity RAMs for the 41C. Since I could not find any reference to this other than a sentence in a Wickes book on Synthethic Programming, I wonder if this module really existed and what its HP part number may have been. Maybe someone here knows more about this?!

Dieter