Vic 20 Memory Expansion

Available on Commodore Vic 20 computers. On the left side.

  1               TOP              22
+-------------------//----------------+
| =================//================ |
+-----------------//------------------+
  A              BOTTOM             Z

UNKNOWN (at the Computer)

UNKNOWN CONNECTOR at the Computer.

Pin	Name	Description
A	GND	Ground
B	CA0	Address 0
C	CA1	Address 1
D	CA2	Address 2
E	CA3	Address 3
F	CA4	Address 4
H	CA5	Address 5
J	CA6	Address 6
K	CA7	Address 7
L	CA8	Address 8
M	CA9	Address 9
N	CA10	Address 10
P	CA11	Address 11
R	CA12	Address 12
S	CA13	Address 13
T	I/O 2	Decoded I/O block 2, starting at $9130
U	I/O 3	Decoded I/O block 3, starting at $9140
V	S02	Phase 2 System Clock
W	/NMI	Non maskable Interrupt
X	/RESET	6502 Reset
Y	n/c	Not connected
Z	GND	Ground
1	GND	Ground
2	CD0	Data 0
3	CD1	Data 1
4	CD2	Data 2
5	CD3	Data 3
6	CD4	Data 4
7	CD5	Data 5
8	CD6	Data 6
9	CD7	Data 7
10	/BLK 1	BLK 1 (Memory location $2000 - $3fff)
11	/BLK 2	BLK 2 (Memory location $4000 - $5fff)
12	/BLK 3	BLK 3 (Memory location $6000 - $7fff)
13	/BLK 5	BLK 5 (Memory location $a000 - $bfff)
14	RAM 1	RAM 1 (Memory location $0400 - $07ff)
15	RAM 2	RAM 2 (Memory location $0800 - $0bff)
16	RAM 3	RAM 3 (Memory location $0c00 - $0fff)
17	V R/W	Read/Write from Vic chip (1=R, 0=W)
18	C R/W	Read/Write from CPU (1=R, 0=W)
19	/IRQ	6502 Interrupt Request
20	n/c	Not connected
21	+5V	+5 VDC
22	GND	Ground

Contributor:

Joakim Ögren

Source:	Inside your Vic 20 by Ward Shrake
	"The Vic Revealed" by Nick Hampshire, 1982, Hayden Book Co, Inc.
	"Vic20 Programmer's Reference Guide", 1992, Commodore Business, Machines, Inc. and Howard W. Sams & Company, Inc.