The AUTO mode (RPN Calculator) is fully implemented, with all math functions verified and operational. The calculator switches between AUTO, PROG, FILE and DATA modes. It stores data into and recalls data from the registers and the extended memory.

The full list is here:

https://github.com/myak555/MK-52_Resurrect/wiki/Appendix-1.-LIST-OF-FUNCTIONS

DATA Mode is also complete. The user can edit all entries and post the data into the RPN stack:

FILE Mode is working partially: the user can traverse the directory structure, create and delete directories. File loading and saving are not yet implemented - after this is done, the MK-52 will become an "operating system"!

The PROG Mode is still a stub, but can execute a step-by-step operations with STEP (ПП) button.

The next item is to store and load files and save the calculator state for "instant on".