This adapter is designed to allow your TI-99/4a to work with standard Atari 2600-style joysticks. The original design for the TI-99 had two joysticks connected via a ‘Y’ cable. While these joysticks were decent for their day, it is difficult to repair the original TI Joysticks today. We offer this board as a solution to that issue. You can use any Atari 2600, Commodore 64 and even the original Sega Genesis (with some conversion) controllers now. Simply plug in the board to the side of your TI, and plug your joysticks in to it and away you go!
There is a case available now for our joystick adapter on eBay! We have purchased the black and silver version ourselves, it is very high quality! It’s nice and solid and the 3D printing work is very smooth. The design looks perfect on the TI-99, like it has been a part of the machine since the beginning. We really do like ours and thought you may like it too! Take a look at finchball’s listing here and see it for yourself.