Thought I'd post about this, I mentioned it in IRC, after seeing it yesterday. This is a new RPN calculator project by SwissMicros, based on the Free42 codebase (a GPL-licensed simulator of the HP-42S calculator, the last high-end 4-level RPN (as opposed to RPL, although the real HP-42S actually does use RPL underneath) scientific calculator that HP released).

Video of the latest prototype:

A presentation on it from HHC 2016:

(terrible audio quality, and some specs are outdated)

Hardware specs that I'm aware of:

STM32L476RG microcontroller clocked at 27 MHz, ARM Cortex-M4, 128 kiB SRAM, 1 MiB flash
8 MiB flash on the board (source:
USB (software will expose this as USB mass storage), infrared connectivity
Real time clock
Sharp 2.7", 400x240 memory LCD
Single CR2032, estimated 50 hours battery life with CPU running, 2000 hours battery life with CPU sleeping and screen on
Rotate-and-click key mechanism, similar to actual HP calculators (SwissMicros already uses such a mechanism on their DMxxL calculators, which are reproductions of the HP-1xC (Voyager) series as well as an adaptation of the HP-41CX to the Voyager form factor)
Metal rear case, matte coating

Somewhere I've seen a claim that they're using pad printing on their keycaps, similar to lower-cost computer keyboards or the TI calculators (HP historically used double-shot keycaps for at least the main legend, if not secondary legends), but still.

There's also videos of a DM42L on YouTube, which was based on the DMxxL case, but I believe has similar hardware to the DM42 (except for the screen), for those that want a smaller and landscape layout calculator. Not sure if that will actually go to production, though.

And, the presentation from HHC 2016 claims under US$200, although I've also seen 250 thrown around, so I don't know which is accurate. For low-volume hobbyist hardware, even the 250 price is probably fair, although it's rather high.

One interesting tidbit from that HHC presentation is that they're expecting a minimum order quantity for a custom variant (that'd be custom keycap and case printing, I assume) to be in the ballpark of 50 units - this could be really interesting for custom calculator projects (not just HP-inspired, although there'll certainly be HP-inspired design language in any calculator using this hardware). It's already known that the WP-43S - a project to create a new high-end classical-style RPN (as opposed to RPL as in the HP-28/48/49/50 families) scientific calculator - has adopted this hardware as its own, because it's already ideally suited to its requirements.

There's a fair amount of discussion of this calculator over on the MoHPC forums, this being one of several threads:
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