1 Commenton Atari 5200 USB Adapter for your PCPosted in Retro By Ali JaniPosted on August 31, 2020

Couple of weeks ago, I received a request on if I could make my retro joystick adapters compatible with Atari 5200 controllers, so I decided to give it a go. So I got myself a controller on eBay for $30 so I can begin the project. I knew right away that i would likely need to design a whole new adapter, given Atari 5200 controllers use 15 pin connectors compared to 9 pin connectors of most of their other consoles.

With some googling, I located the schematic below showing the controller has two potentiometers that control the x and y coordinates and couple of switched for the two fire buttons, and then a 4×4 keypad matrix. So thats total of 12 input lines needed for each joystick. 8 lines for 4×4 matrix, 2 for the stick position, and 2 for the fire buttons. To handle 2 joysticks, I would need at least 24 input ports.

I decided to use a Pro Mirco micro-controller along with a 16 port PCF8575 I/O expander and created the schematic below.

With some modification to my core code I had for the Atari 2600/XT/ST/8Bit Adaper, I was able to get it to work!

For a while I had trouble getting the buttons to work, but with some trouble shooting, I found out the controller I purchased had a bad flex circuit.

Luckily I had a conductive ink pen and it did the magic, at least for my testing. I ordered a new flex circuit for the controller for long term fix but I suspect the ink patch I did will last for several years.

I had 6 ports to spare, so I added common buttons on the unit dor things like Start, Select, etc.. I then designed the PC Board, and cleaned up the code to get it to professional quality, designed and printed a case and success!

Check out my video above to see it in action and give me a thumbs up. If you want to purchase one, you can get them here as well.