trimmtrabb
Participant
Post count: 480

Are you using a gamepad? Here is my retroarch.cfg, located in /home/pi/RetroPie/configs/all/ This file contains your gamepad configuration for all the Retroarch emulators, NES included.

input_player1_joypad_index = "0"
input_player1_b_btn = "1"
input_player1_y_btn = "3"
input_player1_select_btn = "8"
input_player1_start_btn = "9"
input_player1_up_axis = "-5"
input_player1_down_axis = "+5"
input_player1_left_axis = "-4"
input_player1_right_axis = "+4"
input_player1_a_btn = "0"
input_player1_x_btn = "2"
input_player1_l_btn = "4"
input_player1_r_btn = "5"
input_player1_l2_btn = "6"
input_player1_r2_btn = "7"
input_player1_l3_btn = "11"
input_player1_r3_btn = "12"
input_player1_l_x_plus_axis = "+0"
input_player1_l_x_minus_axis = "-0"
input_player1_l_y_plus_axis = "+1"
input_player1_l_y_minus_axis = "-1"
input_player1_r_x_plus_axis = "+2"
input_player1_r_x_minus_axis = "-2"
input_player1_r_y_plus_axis = "+3"
input_player1_r_y_minus_axis = "-3"

input_enable_hotkey_btn = "8"
input_exit_emulator_btn = "9"

input_enable_hotkey_btn = "8"
input_save_state_btn = "5"

input_enable_hotkey_btn = "8"
input_load_state_btn = "4"

input_enable_hotkey_btn = "8"
input_state_slot_increase_btn = "7"

input_enable_hotkey_btn = "8"
input_state_slot_decrease_btn ="6"

input_enable_hotkey_btn = "8" 
input_menu_toggle_btn = "3" 

I have assigned the save/load function to the shoulder buttons of my Xbox gamepad, enabled with a hotkey button (the back button). You can assign your own buttons but you need to determine how the buttons are recognised by the OS. You can install the jtest utility:
sudo apt-get install joystick
and then run:
jstest /dev/input/js0 (assuming you only have one gamepad plugged in)
This will tell you which buttons are being pressed so you can edit the retroarch.cfg accordingly.