1942 pinouts from gopstein@bms.com (Rich Gopstein)

Solder Side		Parts Side

GND			A 1	GND
+5			B 2	+5
+12			C 3	+12
GND			D 4	GND
Speaker -		E 5	Speaker -
Speaker +		F 6	Speaker +
Coin Counter -		H 7	Coin Counter +
key			J 8	key
Shoot 1			K 9	Up 1
Down 1			L 10	Left 1
Right 1			M 11	GND 1
Shoot 2			N 12	Up 2
Down 2			P 13	Left 2
Right 2			R 14	GND 2
2 Player start		S 15	GND
1 Player start		T 16	GND
Coin Switch		U 17	GND
Service Switch		V 18	GND
unused			W 19	Loop 1
unused			X 20	Loop 2
unused			Y 21	Vid GND
Sync			Z 22	Red
Green			a 23	Blue
unused			b 24	unused
unused			c 25	unused
unused			d 26	unused
+5			e 27	*
GND			f 28	GND

* Pin 27 was blank in the manual, but it's probably +5v.