Is it possible to modify the DOSBox source code so that a function like "shutdown" can be assigned from the mapper if the user wants to assign it, but is NOT assigned a key-combination by default? For my project, I would like to have some features (like shutdown) accessible from the mapper if a user wants to assign them to a keystroke, but not pre-assigned a keystroke.

I tried simply leaving the two keystroke parameters blank in the MAPPER_AddHandler code, but that doesn't work. Are there dummy keys or something similar that would do this instead?

Again, thanks for any advice. Probably this is a very elementary question, and I apologize for wasting bandwidth.