// Retro Vintage Connectors

Commodore 64 Cartridge

C64 cartridge expansion port is a 44-pin edge connector providing the 6510 processor address and data buses, control signals, and power to ROM cartridges, disk interfaces, and memory expansions.

// Specifications

Standard

Commodore 64 expansion port

Pin Count

44 (22 per side)

Bus

8-bit data 16-bit address

Voltage

Use Case

C64 game cartridges memory expanders disk interfaces

Compatible

C64 C64C C128

// Pin Reference Table

Pin	Name	Function	Type
1	GND	Ground	GND
2	+5V	5V power	PWR
3	+5V	5V power	PWR
4	/IRQ	Interrupt request	I/O
5	R/W	Read/write	I/O
6	/DOT_CLK	Dot clock	BUS
7	/IO1	I/O area 1 select	I/O
8	/GAME	Game line	I/O
9	/EXROM	External ROM	I/O
10	/IO2	I/O area 2 select	I/O
11	/ROML	ROM low select	I/O
12	BA	Bus available	I/O
13	/DMA	DMA request	I/O
14	D7	Data bit 7	I/O
15	D6	Data bit 6	I/O
16	D5	Data bit 5	I/O
17	D4	Data bit 4	I/O
18	D3	Data bit 3	I/O
19	D2	Data bit 2	I/O
20	D1	Data bit 1	I/O
21	D0	Data bit 0	I/O
22	GND	Ground	GND