Cheap module / advice wanted

[Siegfried]

In this old thread Diego Diaz explained how to build a desk power supply from an "empty" ROM module and a USB power supply. While I recently bought his excellent replacement battery pack I'd still like to build one of those.

I am not sure, however, which ROM module would be "worthless" enough to be sacrificed and nothing is sold for less than 50€ on German EBay. (I have Math, Stat, X-Functions, X-Memory, Advantage and Navigation modules.)

Advice is welcome, offers for cheap/empty/non-working ROM modules with good contacts as well.

[AndiGer]

Maybe the most "worthless" module is the 82106A memory module as it adds only 63/64 registers to a HP-41C?
Andi

[Siegfried]

(11-12-2023 08:25 PM)AndiGer Wrote:  Maybe the most "worthless" module is the 82106A memory module as it adds only 63/64 registers to a HP-41C?

Thanks! Found two from Canada for less than 15 EUR each.