Updating Mega Drive retroarch.cfg changes all systems

[Hockmiester]

Hi.
I wanted to correct the btn configuration for the mega drive. (using arcade joystick+8 buttons in two lines of 4).
I went into the advanced configuration option from RetroPie. Selected the megadrive retroarch.cfg (not global or all) and added my btn config (mine are different from the help example).
(They look like this etc)
input_player1_b_btn = 2
input_player1_a_btn = 1
• I also did hot keys and the Axis for the joystick.
After some trial and error the Mega Drive correctly now loads A,B,C & X,Y,Z across the buttons.
However...this is made all other systems stop working (for example) SNES or PSP the only input that now responds is the Bluetooth keyboard.
I went into the PSP config as a test, and added some btn configurations and those buttons started working.
Question...
A: I really don't want to have to map every system 1 by 1 like I did for the megadrive but I do want the buttons correct as a they appeared on the original gamepad (my arcade buttons are 2 lines of 4 buttons but the megadrive defaulted to have C in position top row button 2 rather than bottom row button 3 before I corrected it). It shouldn't have updated all systems, so how do I correct this?
B: While I'm asking if the D-pad input text is input_player1_up_axis = -1 then what is the analogue stick on a PSP text for my reference (should I need to map every configuration separately)?
Thanks
Mike

[edmaul69]

@Hockmiester why dont you just open the file /opt/retropie/configs/megadrive/retroarch.cfg and manually add them? But you need to undo whatever configs you created.