For example, if Player 1 moves UP-'''and'''-RIGHT then UP and RIGHT are shortcut with each other. In result, without the diodes, Player 2 would automatically move UP-'''and'''-RIGHT whenever trying to move UP-'''or'''-RIGHT.
The diodes are, of course, needed only on one connector (eg. Joystick 2 only). The schematic with diodes on both Joystick 1 and 2 connectors is a bit overcomplicated.
== See Also ==