Which calculators run RPL under the hood?

[rprosperi]

Really, really nice detailed post Giuseppe, thank you for all the research work, the numerous convenient references & links and for sharing this here.

Hopefully as folks read this, some additional facts can be added to further clarify some of the remaining mysteries, but the evidence you present is pretty compelling.

But I still would like to know why, with the RPL system available, HP would choose to build all the lower-end machines from scratch. Was saving a little ROM and RAM in those models really less expensive than writing and testing code for those same models from scratch? It's hard to compare these economics today with the huge drop in price of hardware and always rising price of software development.