It convert SFC/SNES Controller for SNK Neo Geo use.

Each button (A,B,C,D) have independent Autofire ON/OFF
2 Speed Levels of Auto Fire on A ,B, C and D button

Auto Fire Control :
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L + A + Select  --> A button slow fire on.
L + B + Select --> B button slow fire on.
L + C + Select --> C button slow fire on.
L + D + Select --> D button slow fire on.

R + A + Select  --> A button fast fire on.
R + B + Select --> B button fast fire on.
R + C + Select --> C button fast fire on.
R + D + Select --> D button fast fire on.

L + R + Select --> All buttons autofire off.
L + R + A         -->  A button autofire off.
L + R + B         --> B button autofire off.
L + R + C         --> C button autofire off.
L + R + D         --> D button autofire off.

* 3D printing case on middle of the cable, quality is different from each
* You can modify your SNES controller buttons color to fit Neo Geo one