LJN Video Art cartridge dumper

In 1987, toy company LJN made a home game console called the "Video Art." It has a handful of games that come on cartridges and is 6805-based.

This repo contains the source for a hardware/software combination to dump these cartridges to ROM files, which can be used in a hypothetical future emulator or clone device.

This device was developed as part of a Leaded Solder blog entry. It cost money and time to develop; if you want to support things like this in the future, please contribute to the Patreon.

Dumped Games

So far, only one game has been dumped by this device:

• Disney Story Book

The remaining eight games of the Video Art system have been dumped by others:

• Video Art Activity Cartridge ljn_act-1
• A Trip to the Zoo tripzoo
• Disney Colouring Book disneycb
• Looney Tunes looney
• Marvel Super-Heroes marvel
• My Dream Day dreamday
• My Favorite Doll favdoll
• On the Move onmove

If you have a Video Art cartridge that is not listed here, please get in touch.

Hardware

Requirements

You will need:

• An Arduino Uno or compatible. I used the "Elegoo Uno R3" from Amazon for development and testing;
• A USB cable;
• 2x DIP 74HCT595 (74HC595 is probably fine);
• 1x DIP 74HCT165 (74HC165 is probably fine);
• The cartridge slot for the LJN cartridge, I used a TE AMP 5530843-3;
• A length of component leg (e.g. leftover resistor) or some wire;
• Arduino shield stacking headers (I got mine off Amazon)

Assembly Instructions

Assembly is a bit tricky, so go shortest to tallest component as you are populating the board. The stacking connectors should go last.

The cartridge connector should be tilted back slightly to make sure there is clearance with the stacking connectors.

Stick a wire or a bent resistor leg through the "0Ω" resistor footprint on the board.

There is no need to populate the two test points TP1 or TP2; these are meant for a beaded test hook, in order to debug the board using a logic probe.

It is challenging to make the stacking connectors go in straight; if you have a better way, please let me know. I used sticky tack/poster putty and bent the pins to mate with the Uno base board.

Software

Build instructions

1. Install Arduino IDE. I developed this with version 2.2.1, but I assume any Arduino editor should work for this purpose.
2. Open the .ino file.
3. Connect your Arduino Uno (or compatible) to the USB port and upload the firmware to the board. This might require some configuration; check your board vendor for more details.
4. Insert the cartridge. The label side of the cartridge must face outwards, towards the text on the PCB that says "label side this way."

Usage instructions

For now, there is no software client for this dumper. Instead, you'll want to use the Serial Monitor from the Arduino IDE.

When the Uno starts up, it should display a message like this:

LJN VideoArt ROM Dumper
OE is on pin 10

Type dump into the text input, press return, and wait for the dump to complete. The monitor should slowly fill with hexadecimal values from the ROM, followed by the message done.

Open the interpreter.py Python script in your favourite text editor.

Copy and paste the hex values from the Arduino Serial Monitor output into the string DUMP_STRING. Make sure none of the old string is there, and make sure it makes a valid Python string (i.e. that it is surrounded by single quotes and is all one line.)

Run the interpreter.py Python script. It should generate a file called rom.bin that is exactly 16,384 bytes long.

If you know that your ROM is longer than 16,384 bytes, this board may not work for you. Please contact me immediately and we'll work something out.

Other Commands

Not many commands are supported; this list is here for mostly diagnostic purposes.

Command	Does what?
dump	Dumps a 16K ROM
info	Version identification for the firmware.
oelo	Pulls the output-enable line of the cartridge LOW (enabled)
oehi	Pulls the output-enable line of the cartridge HIGH (disabled)