Modding 12C+

This page is still under construction…

More info: https://lithcore.cn/hp12c-modding-assets/

Flashing 10C, 11C, 16C ROM

16C is still extremely buggy, the decimal mode is almost unusable, probably something to do with ALU mode switching; 15C doesn’t work at all because the 12C+ firmware doesn’t support paging. 10C and 11C should work with no problem.

Notice: The following sequence only works for REV2 (with rev.2 written on the back plate). It will not work on a more commonly seen REV 1, which I don’t possess yet. It should work in a similar way, but I don’t think REV 1 allows flash access without forced erasing, which deletes the nut emulator.

How to (12C+ rev2):

  1. Extract RAW Nut Processor ROM binary file from 10C or 11C.
  2. The original ROM file is 12-bit per word, convert it to 16-bit big-endian binary. (You should look for certain ARCHIVEs of the nonpareil emulator for the ROM file)
  3. Flash the binary file into address 4800-77FF
  4. Enjoy