Task: Make an Atari 8-bit Computer Cartridge
Needed: Cartridge parts, EPROM programmer, soldering station or iron
Time: 1-2 hours
As I have mentioned in previous posts, I had tons of fun making my own Atari 2600 game called Gene Medic. I sent the binary and artwork off to Atari Age and had them make several cartridges for me. Since then, I have wanted to make my own cartridge since the parts and instructions can all be found online. I decided to make an Atari 8-bit computer cartridge as my first project. I will make a 2600 cartridge another time. The process is very similar for both.
It took me a little while to get set up for this project. I purchased a new soldering station about a year ago and have been slowly accumulating all the supplies I needed to make cartridges and for other Atari hardware projects such as replacing ROM chips in the 8-bit computers. Below are the step by step instructions for making your own cartridge for the Atari 8-bit computers. My build is based on these plans.
Please note that this build uses a circuit board and cartridge case from Corei64. You can do this cheaper (~$20 instead of $30) using components from the Vintage Computer Center (see comments below).
You will first need a soldering iron or soldering station for this project. Soldering is required. I have previously posted about the setup I purchased.
Order the supplies. You will need a circuit board, a cartridge case, an EPROM chip, a capacitor, and a logic chip if you are making a 16K cartridge (not needed for 8K cartridges). Here are the ones I purchased which I have confirmed work. Note that the Corei64 delivery took like three weeks to come in.
- I got my 3D-printed cartridge case from Corei64.com. They have multiple options and you can choose the color you want. I purchased this one for just under $14 (a little pricey!).
- Corei64 also sells the circuit boards. They cost just under $10 each.
- I purchased my EPROMs from Jameco for about $4.50 each.
- I also purchased my capacitors from Jameco for less than $0.20 each.
- Here are the optional NAND logic gate chips from Jameco needed for 16K cartridges. These are little over $1 each.
- You will also need a short jumper wire if you are making an 8K cartridge. I simply used some of the excess wire I had to cut off of the capacitor.
Once you have all the parts listed above, the next step is to burn the binary file of your software onto the EPROM chip. I have previously posted about the programmer I purchased and the step by step instructions for putting the binary file on the EPROM chip. You will need this chip and your software loaded for the next steps.
Assemble and solder the components on the circuit board. I followed these instructions from Pixels Past. The image below is taken from these instructions and shows the circuit board with the components. Note that the logic chip is shown to the left of the EPROM for the 16KB cartridges. For the 8K cartridges you need to solder a jumper wire connecting pins 10 and 11. You can see the pins in the above circuit board photo on either side of the X printed on the board. The only challenge I had following these instructions was that the pins on the EPROM were bent slightly outward and had to be carefully straightened to fit into the circuit board. Also note the orientation of the EPROM with the notch to the left toward where the logic chip or jumper wire goes.
Assemble the cartridge by placing the finished circuit board in the cartridge shell. The shell comes with an Allen wrench and opens in two pieces by removing four screws. Note that I had trouble getting my circuit board to fit cleanly in the shell. I had to use my Dremel to remove some of the plastic to get the circuit board low enough so the the shell would close completely. This was actually the most difficult and frustrating part of the process. You will likely need to do the same so be prepared.
Boot the cartridge in the Atari for the final test! Mine worked on the first try.
This was a fun project. I put Altirra 8K BASIC on my cartridge. Really happy to be able to pop that in for running programs which need a faster BASIC.
These homebrew cartridges are a bit expensive at about $30 each. You might be able to save some money printing your own circuit boards and cartridges. I considered that but decided not to in the end. I may revisit this at a later time when I need to make some cartridges for my own games.
Here is an additional source of circuit boards and injection-molded cartridge shells from the Vintage Computer Center. An 8K circuit board runs about $6. The shells are also $6. This would be a cheaper option. This note was added after I did the build above.
Making cartridges isn’t really needed anymore given all the flash cartridges such as the Maxflash device I wrote about earlier. However, I found it very rewarding to burn an EPROM and build an authentic cartridge. Definitely give it a try.