Tech: Playchoice Super Mario 2 and 3

Archived from groups: rec.games.video.arcade.collecting (More info?)

OK,
I have 2 cartridge boards here, a Super Mario 2 and a Super Mario 3. I
know for a fact that I have one of each. I can't plug them into
anything because I have already parted the game. Here is my dilemma...
BOTH boards are marked Super Mario 2, and one board has 3 ROM chips
with an empty chip socket while the other uses all 4 sockets.

I'm assuming that the one with the 4 chips is Super Mario 3... Can
someone please confirm this for me??

Thanks!
-Mike