Many Super Nintendo games — Micro Machines, Super Bomberman, Secret of Mana, NBA Jam… — accepted a multitap plugged into the console's port 2, for up to four players.
There is nothing to configure. As soon as more than two pads are connected, Recalbox sets port 2 to multitap when the game starts. This is automatic with the emulator used by default on every machine.
The only thing to get right: connect every pad before launching the game, and make sure each one is configured. The setting is decided when the game starts — a pad plugged in mid-game will not be picked up.
The multitap only works if the game itself supports it. On a two-player game, it brings nothing.
The automatic behaviour applies to snes9x and snes9x2010. If you picked another core for this game or folder — mesen_s, bsnes, mednafen_supafaust — you have to ask for the multitap by hand:
HOTKEY + B.Settings > Configuration, and enable Save Configuration on Quit.Main Menu > Quick Menu > Controls > Port 2 Controls.Device Type option, scroll until Multitap is displayed.Manage Remap Files: choose to save the setting for the game or for the content directory, as you prefer.Restart.The multitap only works if the game itself supports it. On a two-player game, enabling it brings nothing and may even stop the second pad from responding: in that case, set
Device Typeback to the standard controller.
A more durable alternative is to use a RetroArch override instead of the remap menu.