After having need of it for some time, we have finally made ourselves a spot on the Cemetech forum index specific to HP calculator news, projects and programming support. I've looked through some of the subforums, like the Technology and Calculator open topic, and moved what topics I could find over to the new section. If you happen to find any other topics I might have missed that are specific to HP calculators, or maybe something about Casio not in the Casio section, let us know, and we'll see if it's something that needs to be moved. We look forward to continuing to drive discussion and exploration of HP's calculators old and new here at Cemetech.
On that note, Lionel Debrouxl, an administrator of French-language TI site TI-Planet, mentioned on an HP enthusiast forum that he succeeded in making a small replacement firmware image for the HP Prime. He describes it as a "DummyOS", a proof-of-concept that it's possible to put third-party OSes on the device, but it's a nice reminder that the platform is relatively accessible for developers. While it's not yet clear how to write ASM/C programs for the Prime's built-in operating system, the Prime's S3C2416 ARM processor is supported by Linux, and building a Linux image for the device with some driver work is in the realm of possibility with a few weeks of work by community members. We look forward to watching or perhaps participating in this research.