Well, I did get his general idea, in spite of the spelling errors. ^_^ It seems the problem was not having installed the Custom Config file (it is kind of inconspicuous, there). So I have been able to successfully open and edit the blight_input.config file - and the result is - NOTHING! The P key is STILL mapped to Pause! Why?! Mupen is still showing all the same default keys in the options menu, and indeed, the P key still pauses the game, despite my having "remapped" it. So now what?!