I know it's possible to wire it, but is there any site that sells an adapter that allows you to connect a Famiclone 9-pin controller and plug it in to a Famicom 15-pin port?
You would probably have to make one. I actually think I have the parts to make one, using the controller input ports from a sega genesis.
It's a pretty simple adapter.
All you need is one of these:
http://www.active123.com/DBF1510-DSub-Female-15-Pin-Solder-Pkg10-Prodview.html
Two of these:
http://www.active123.com/DBM0910-DSub-Male-9-Pin-Solder-Pkg10-Prodview.html
133MHz (http://www.famicomworld.com/forum/index.php?action=profile;u=245) provided schematics (http://www.retrogames.cl/imagenes/proyectos/twinhead/esquematico.jpg)
Mixed with schematics provided by aha2940 (http://www.famicomworld.com/forum/index.php?action=profile;u=2362)
(http://i1346.photobucket.com/albums/p695/g-pulido/gamepad-famiclone-pinout_zpsfe315633.png)
Don't look at the colors - just the positions.
I'm sure those standard female 15-pin connectors are too deep for the Famicom expansion connector to fit. That's why we use Neo Geo extension controllers. http://www.tototek.com/store/index.php?main_page=product_info&cPath=23&products_id=58
Yeah - I've heard about that issue. The 9-pin famiclone port is not so deep as the 15-pin port. It's pretty nasty to grind off the metal edges...
Yay! Now I can buy those funny-looking 9-pin playstation-like controllers. Anyone know if they're any good?
Not really no. The cord is maybe 45cm long and they tend to break really quickly.