Seven HP-71B Calculators and Four ThinkJet Printers

[rprosperi]

This listing was quite strange, after this listing disappeared (I assume pulled down) I too could not find any trace of it, as if it was never listed. I wonder how that is arranged....???? Hmmmm....

As for the CR RAM modules, the 64K module is ootb, configured as 2 x 32 KB modules, but by cutting and jumpering some traces on the board, can be readily converted to a single 64KB module, which is important as this is essential to house the image which will burned to a 64KB EPROM module.

I'll guess that CMT built the board for the 128KB module using the same technique, of cutting/jumpering traces to daisy-chain the 4 x 32 chips into a monolithic 128KB RAM chip. I have 2 of these 128K modules which act as 4 x 32, and a third which I have not installed yet, so not positive about how they ship, however just open the module case and examine the leads, you'll probably find cut traces, etc.

It's a long thread, but there's info in here about this topic - can't find links at the moment, but both J-F and Paul Berger have created and shared docs on this topic, if not shared by someone else (Dave F) shortly, I can send you the docs.

https://www.hpmuseum.org/forum/thread-10300.html