Quote Originally Posted by contra4life View Post
Guess i should have read the whole post rather than just commented on the pic...

But now that i have read everything... it would seem that it may have been used to test newly developed controllers, and maybe the switch told the system to display error codes if certain things didn't work right... that of course meaning that a special trouble shooting cartridge had to be plugged in...

thats what i got...
Could also have to do with the four player adapters for the Genesis possibly, since there were compatiblity problems between the EA games, EA splitters, etc.