When I try to change the controls for mame, the ones that I change no longer work and the old controls don’t work either. I have tried to change them in the master conf file but that seems to jot work either. Also can not change them from the GUI running the Roms (f1) as the “next” button is not mapped. I am using a standard USB keyboard. Thanks.

UPDATE 1: After updating the Pi both OS and RetroPie, the emulator of choice is going to be MAME4All (See HERE for more details)

UPDATE 2: After finding out that other emulators use RetroArch, a little digging forun that in the GUI you can not edit Keyboard keys, just controller keys. SEE HERE You need to edit the controls in the .cfg files under /home/pi/RetroPie/configs/ If please note non letter key as follows:

# Keyboard input. Will recognize letters ("a" to "z") and the following special keys (where "kp_"
# is for keypad keys):
#
#   left, right, up, down, enter, kp_enter, tab, insert, del, end, home,
#   rshift, shift, ctrl, alt, space, escape, add, subtract, kp_plus, kp_minus,
#   f1, f2, f3, f4, f5, f6, f7, f8, f9, f10, f11, f12,
#   num0, num1, num2, num3, num4, num5, num6, num7, num8, num9, pageup, pagedown,
#   keypad0, keypad1, keypad2, keypad3, keypad4, keypad5, keypad6, keypad7, keypad8, keypad9,
#   period, capslock, numlock, backspace, multiply, divide, print_screen, scroll_lock,
#   tilde, backquote, pause, quote, comma, minus, slash, semicolon, equals, leftbracket,
#   backslash, rightbracket, kp_period, kp_equals, rctrl, ralt