JAMMA connector pinout

MVS edge connectors aren't fully JAMMA compliant.

Like true JAMMA edges, the pad pitch is .156in (3.96mm). There are 28 pins per side (key included), 56 total.

Many harnesses use regular 56 pin board connectors which don't have the key to avoid accidentally plugging them backwards. Doing so will certainly fry the inputs chip (NEO-C1...), be careful.

Note that the G, I, O, and Q letters aren't used to avoid confusion with other characters.

MVS pinout

Checked infos from [HardMVS.com]. The arrows represent the signal direction from the MVS board.

Bottom			Top
GND		A	1	GND
		B	2
+5V		C	3	+5V
		D	4
Unused		E	5	Unused
+12V		F	6	+12V
Key		H	7	Key
Coin counter #2		J	8		Coin counter #1
Coin lockout #2		K	9		Coin lockout #1
Left speaker		L	10		Right speaker
Test button		M	11		Mono audio
Video green		N	12		Video red
Video sync		P	13		Video blue
Service button		R	14	Video GND
Coin switch #4 P2		S	15		Coin switch #3 P1
Coin switch #2 P2		T	16		Coin switch #1 P1
P2 Start		U	17		P1 Start
P2 Up		V	18		P1 Up
P2 Down		W	19		P1 Down
P2 Left		X	20		P1 Left
P2 Right		Y	21		P1 Right
P2 button A		Z	22		P1 button A
P2 button B		a	23		P1 button B
P2 button C		b	24		P1 button C
P2 button D		c	25		P1 button D
Select down		d	26		Select up
GND		e	27	GND
		f	28