9 pin D-sub male (D9M) at the computer.

Source: VIC-20 User Manual

 

44 pin female edge at the computer. The pins function as described below:

Pin	Name	Description	Pin	Name	Description
1	GND	System ground	A	GND	System ground
2	CD0	Data bus bit 0	B	CA0	Address bus bit 0
3	CD1	Data bus bit 1	C	CA1	Address bus bit 1
4	CD2	Data bus bit 2	D	CA2	Address bus bit 2
5	CD3	Data bus bit 3	E	CA3	Address bus bit 3
6	CD4	Data bus bit 4	F	CA4	Address bus bit 4
7	CD5	Data bus bit 5	H	CA5	Address bus bit 5
8	CD6	Data bus bit 6	J	CA6	Address bus bit 6
9	CD7	Data bus bit 7	K	CA7	Address bus bit 7
10	/BLK1	8K decoded RAM/ROM block 1 ($2000 - $3FFF)	L	CA8	Address bus bit 8
11	/BLK2	8K decoded RAM/ROM block 2 ($4000 - $5FFF)	M	CA9	Address bus bit 9
12	/BLK3	8K decoded RAM/ROM block 3 ($6000 - $7FFF)	N	CA10	Address bus bit 10
13	/BLK5	8K decoded RAM/ROM block 5 ($A000 - $BFFF)	P	CA11	Address bus bit 11
14	/RAM1	1K decoded RAM block ($0400 - $07FF)	R	CA12	Address bus bit 12
15	/RAM2	1K decoded RAM block ($0800 - $0BFF)	S	CA13	Address bus bit 13
16	/RAM3	1K decoded RAM block ($0C00 - $0FFF)	T	/I/O2	I/O block 2 (located at $9600)
17	VR/W	Read/Write line from VIC chip (high-read, low-write)	U	/I/O3	I/O block 3 (located at $9C00)
18	CR/W	Read/Write line from CPU (high-read, low-write)	V	S02	Phase 2 System Clock
19	/IRQ	Interrupt request line to 6502	W	/NMI	6502 Non maskable interrupt
20	n/c	Not connected	X	/RESET	6502 Reset pin
21	+5V	+5 VDC	Y	n/c	Not connected
22	GND	System ground	Z	GND	System ground

Source: VIC-20 User Manual, VIC-20 Programmer's Reference Guide

 

 

 

5 pin DIN 180� (DIN 41524) female at the computer.

Notice that the video output is on two pins. They are the same (wired together inside the computer) on some versions, and output a slightly different signal level in others. Use pin 4 for interfacing a video monitor such as the 1702 and pin 2 for the shield (ground).

Note: The prewired CBM cable should be the two wire type. A three wire cable used for Y/C video (C64 or C128) will not work.

Note: Be careful of the +6 volt line! It's there to source power to the -external- RF modulator used with the VIC20.

Source: VIC-20 User Manual, Ray Carlsen's C= Repair Articles

 

6 pin DIN (DIN 45322) female at the computer.

1	SERIAL SRQ IN	Serial service request in: Any device on the serial bus can bring this signal low when it requires attention from the VIC. The VIC will then take care of the device.
2	GND	Ground
3	SERIAL ATN IN/OUT	Serial attention in/out: The VIC uses this signal to start a command sequence for a device on the serial bus. When the VIC brings this signal low, all other devices on the bus start listening for the VIC to transmit an address. The device addressed must respond in a preset period of time; otherwise the VIC will assume that the device addressed is not on the bus, and will return an error in the status word.
4	SERIAL CLK IN/OUT	Serial clock in/out: This signal is used for timing on the serial bus.
5	SERIAL DATA IN/OUT	Serial data in/out: Data on the serial bus is transmitted one bit at a time on this line.
6	NO CONNECTION	Note: in some models pin 6 is /RESET

Source: VIC-20 User Manual, VIC-20 Programmer's Reference Guide

 

6 pin male edge at the computer.

Source: VIC-20 User Manual

 

24 pin male edge (DZM 12 DREH) at the computer.

Note: pin 2 is +5VDC, pins 10 and 11 are +9VAC

Upper side
1	GND	Ground
2	+5VDC	100mA max
3	/RESET	By grounding this pin, the VIC will do a cold start, resetting completely and erasing any program in memory.
4	JOY0	This pin is connected to joystick switch 0 (See game port).
5	JOY1	(See game port.)
6	JOY2	(See game port.)
7	LIGHT PEN	This pin also acts ad the input for the joystick fire button (See game port).
8	CASSETTE SWITCH	This pin is connected to the sense cassette switch line.
9	SERIAL ATN IN	This pin is connected to the ATN IN line of the serial bus.
10	9VAC	(+ phase) Connected directly to the VIC transformer.
11	9VAC	(- phase) Connected directly to the VIC transformer.
12	GND	Ground
Bottom side
A	GND	Ground
B	CB1	The VIC gives you complete control over Port B on VIA chip #1. Eight lines for input or output are available, as well as 2 lines for handshaking with an outside device. The I/O lines for Port B are controlled by two locations. One is the port itself, and is located at 37136 ($9110 hex). Naturally you PEEK it to read an input, or POKE it to set an output. Each of the eight I/O lines can be set up as either an input or an output by setting the data direction register properly. It is located at 37138 ($9112 hex).
C	PB0
D	PB1
E	PB2
F	PB3
H	PB4
J	PB5
K	PB6
L	PB7
M	CB2
N	GND	Ground

Source: VIC-20 User Manual, VIC-20 Programmer's Reference Guide

 

 

 

VIC-20 POWER SUPPLY (PSU) SOCKET

 

Early VIC-20s (pre-Cost-Reduced models) got a 2-pin AC socket on the right side of the unit, further back than the ON/OFF switch. The pinouts for this socket are simple. Both pins expect 9-10V AC voltage from the secondary (output) of the transformer.

Later VIC-20s (the Cost-Reduced, or CR, model) got the same socket as the Commodore 64, so a C64 PSU is 100% ok to use instead if you don't have the VIC-20 PSU that came with it. These are the pinouts of this newer PSU:

Pin Meaning

1 -
2 GND
3 -
4 -
5 +5V DC
6 +9V AC
7 +9V AC

 

Irrelevant for the VIC-20, but as an FYI: some C64 PCB versions have pins 1, 3 and 4 connected also (pins 1 and 3 are to GND, and pin 4 is +5V DC), whilst some have pin 4 disconnected, but a service note says that this should be added via an internal wire.

Of course, depending on the precise model VIC you have (North American model or European, etc), the required input voltage for the transformer differs:

North America = 110-120V AC @ 60Hz, 40W (part # 902503-02)
Europe = 220-240V AC @ 50Hz, 40W (part # ?)