Expansion port

The VIC-20 cartridge port is also referred to as the memory expansion port, or expansion port. It is a .156" pitch socket on the left-hand side of the VIC-20 and provides a direct bus link to the computer for adding all kinds of devices. It was mostly used for video game cartridges and peripherals such as memory expansion.

Pinout

Pin	Connection	Pin	Connection
1	GND	A	GND
2	CD0	B	CA0
3	CD1	C	CA1
4	CD2	D	CA2
5	CD3	E	CA3
6	CD4	F	CA4
7	CD5	H	CA5
8	CD6	J	CA6
9	CD7	K	CA7
10	BLK1	L	CA8
11	BLK2	M	CA9
12	BLK3	N	CA10
13	BLK5	P	CA11
14	RAM1	R	CA12
15	RAM2	S	CA13
16	RAM3	T	I/O2
17	VR/W	U	I/O3
18	CR/W	V	S02
19	IRQ	W	NMI
20		X	RESET
21	+5V	Y	Audio in (CR only)
22	GND	Z	GND