COMMODORE VIC-20 32KB MEMORY EXPANSION CARTRIDGE (ver. 951026)

Hello,

This is a tested and working project. (Tested on a NTSC Commodore VIC-20 plugged to a C64 PSU)

COMMODORE VIC-20 32KB MEMORY Expansion Cartridge is an Easy DIY project, all components are through hole, marked on the PCB, Easy to solder, Easy to make ;)

Many thanks to Adam Bergström from SWEDEN

https://www.commodore.ca/manuals/funet/cbm/documents/projects/memory/vic20/32kB.html

http://www.zimmers.net/anonftp/pub/cbm/documents/projects/memory/vic20/32kB.html

Features:

+ 32k RAM in four 8k blocks located in memory at:

$2000 (BLK1)

$4000 (BLK2)

$6000 (BLK3)

$A000 (BLK5)

This gives you an additional 24k BASIC memory (27,5k total!), and 8k at the cartridge area.

+ Ability to load and run cartridge-images from disk or tape.

+ Write enable/disable switch, lets you run copy protected cartridge images.

+ Switch to enable/disable the whole extra-memory, to let you use the VIC-20 unexpanded.

+ Reset switch.

COMPONENTS:

HY62256A, (DIP28) 32 Kbyte static RAM, 100ns (any 32Kx8bit SRAM faster than 500ns should be O.K.)

74LS147 (DIP16)

DIP28 WIDE IC SOCKET

DIP16 IC SOCKET

2 PCS. 3pin 2.54mm SPDT slide SWITCH

2 PCS. 100nF CERAMIC CAPACITOR

220 μF 16V ELECTROLYTIC CAPACITOR

RIGHT ANGLE TACTILE BUTTON (For RESET Button)

THIS PCB

Please choose: Edge connector YES and Bevelling Yes (45°)

3D printable standard Commodore VIC-20 cartridge box

(Needs holes for switches and Reset button)

https://www.thingiverse.com/thing:69261

If you have a programmer capable of testing IC chips, such as the 74LS series and static RAM chips, you should remember to test them before soldering. Some chips may be defective. (TL866 Minipro Programmer can test some logic ICs and static RAM chips)

In order to protect your electronical devices, always turn off your Commodore before connecting or disconnecting the cables or any other device.

Gerber files and component list are subject to change without notice. Before paying for the PCBs, be sure to update your orders!

As you can see I have uploaded many projects and I am still working on new projects. If you have any questions, please look for answers online. Unless I specify explicitly, all my projects are tested and confirmed to work under normal circumstances before being shared. I'm sorry I didn't have enough time to answer all the questions.

Use this PCB at your own risk !

Have fun

Thank you.

Here are some PCBs you can use for VIC-20 (VC-20)

COMMODORE VIC-20 35KB (27+8) RAM EXPANSION CARTRIDGE

COMMODORE VIC-20 SD2IEC + 35KB (27+8) RAM EXPANSION CARTRIDGE

COMMODORE VIC-20 ROM CARTRIDGE for 8x 8KB ROMs

COMMODORE VIC-20 ROM CARTRIDGE for 4x 16KB ROMs

COMMODORE VIC-20 Pi1541 + 35KB (27+8) RAM EXPANSION CARTRIDGE

COMMODORE VIC-20 32KB MEMORY EXPANSION CARTRIDGE (ver. 951026)

SD2iEC DISK DRIVE EMULATOR POWERED from USER PORT

RASPBERRY Pi1541 ZERO HAT (DISK DRIVE EMULATOR)

VIC-20 CHARACTER ROM REPLACEMENT ADAPTER (MOS 901460-03)

BASIC ROM & KERNAL ROM REPLACEMENT ADAPTER REV.3