Yes it has a little switch , set accordingly for play on TG16 or PCE, from this point on it will patch roms on the fly to play on the system it is plugged into. I play both PCE and TG16 games on my TG16 for example.
Just to reinforce, I have a Japanese system and US ROMs work just fine as they are patched when they are loaded. Only a single byte has to be changed to make the games run. From the user's point of view all you need to do is set the position of the switch to match what region your console is and then forget about it. Unless you are using it on two systems of different regions you'll never need to worry about the switch again.
