The Rogue HP-12c

[brouhaha]

Given the firmware date, and the screw for the battery compartment, and if you can see gold contacts in the pogo connector holes, then it's highly likely that it uses the same electronics as the "normal" post-2015 12C. If so, you should be able to dump the firmware using the cable from The Calculator Store, and SAM-BA.

When you dump firmware from these, use a starting address of 0x4000 and size of 0x1c000 to dump just the calculator firmware, to get an image you can program into another calculator.

It's potentially of interest to also dump to a separate image starting addrexx 0x0000 and size 0x4000, which is the bootloader, for comparison to the bootloader of other recent flashable Voyager models.

Based on the descriptions of behavior of this model, it seems like someone at HP or Moravia may have written new 12C firmware that doesn't simulate the Nut processor.