Using the LM339, how would this be achieved?
In my head:
X+ goes to 5, 7.
Y+ to 9, 11.
VCC to 3
GND to 12
1, 2, 13, 14 goes to Up, Down, Left, Right on the Gameboy Board
Which leaves the inverting inputs (4, 6, 8, 10)
What would be connected to these? Would they get resistors going to GND...