This superb little adapter enables secure connections between Sega Mega Drive/Genesis  controllers and Amiga or Commodore 64 systems.
 
It features three switches:
   Switch 1 selects either C64 or Amiga;
   Switch 2 allows you to choose the fire button as 'B' or 'C'
   Switch 3 determines if the second fire input is 'Up' or a fire command..
 
It supports both wired and wireless controllers and has been successfully tested with various devices, including 8bitdo retro receivers, retro-bit 2.4GHz controllers, original 3- and 6-button controllers, and numerous third-party options. The only exception found was the 2.4GHz M30 from 8bitdo, which is incompatible, while the Bluetooth version of the M30 works without issues.
 
This will turn sega controllers into two button controllers for the Amiga/C64
 
A selection of Sega Megadrive Controllers are available here
The Amiga 600 will require a patch lead, Available here