I had no idea about any of this. Very cool. A few months back, I disabled the lockout chip on my NES and enabled the extra music channels by soldering a wire between the relevant pins with resistors in between, then installing a rocker switch to disable it if the buzzing got to me. In the last year, I've probably spent more time doing projects like that than actually playing games.
What do you use your famicom adaptor for, just playing with original famicom controllers?