So I'll go ahead and mark this as solved and thank you for your help! Given that, the documentation for lr-mupen64plus is outdated. After firing up the game, the controller's A and B buttons worked as expected! So it looks like the mapping of B and Y buttons in RetroPie/ES are being mapped to the game's A and B buttons in lr-mupen64plus and lr-mupen64plus-next, respectively. Looking back at the wiki, I decided to try the mapping that was documented for Mupen64plus, where the game's A and X buttons are mapped to controller's C down and C left, respectively. I'll try that config file from the database on both setups and see if that yields any different resetting RetroArch's main configuration yielded the same results.

ДЄnd the mappings you had me check in es_input.cfg are exactly as they should be: The game's B button was mapped to some 'Y button (left)', and the physical A button on the controller was mapped to (C1), whatever that is. Once I fix those, native mupen64 works fine, but altering the libretro mapping doesn't.ДЄt this point, is it possible there is some bug in the mapping of controls for lr-mupen64plus? Or a possible incompatibility with this controller? Really appreciate any thoughts you may here's what the RetroArch RGUI had for controller mappings. And the joystick configuration in /configs/n64/ is incorrect as in my previous test, specifically for the A, B, and C down buttons: C Button D = button(6) button(2)

The joystick configuration in /configs/retroarch/autoconfig/ is 100% correct however in lr-mupen64plus the B button controls the A button, and the A button does nothing. cfg and /opt/retropie/configs/n64/InputAutoCfg.ini my results are identical to my previous test. I followed the same procedure in my original test, only enabled ssh and wifi, and configured the Retrolink N64 controller using the ES mapping prompt and recommended mappings for lr-mupen64plus.ДЄfter checking /opt/retropie/configs/all/retroarch/autoconfig/Generic USB Joystick.

Just for curiosity sake I took a Raspberry Pi 3 and loaded the latest 4.5.1 RetroPie image on a fresh SD card.

Callibrate retrolink n64 controller