Pinouts and Schematics
These are the pinouts for the original 8-bit Nintendo controller (7 pins) and and the Famiclone (DB9 or 9 pins). This will help you if you want to build your own adapter:
Official Nintendo Entertainment System Pinouts
Famiclone Dendy FC2003 Pinouts
The colors may differ on your controllers and/or extension cables. However, the place for each pin – data, strobe, clock, +5V, ground, trigger pull, and light sensor – are all the same.