i'm really proud of you swami since you have come this far on modifications i wonder if you would want to go a little further
sorry i use so much glue on the plug end but you will need to carefully cut some away to get to pin #12 run a length of wire down to the pc connection and use a switch to allow it to do the job of pin so you will want the wire coming from pin 9 on one side of the switch pin 12 on the other and the center pin attach it to the place where you detached pin 9 (the pc controllerconection pin 1 i think)
why do this?
well it will put the atari in tracball mode that adds some neat features like it will allow pole position to switch gears with the keypad
and on missile command the cursor will still move super quick but it will stay where you leave it instead of snapping back to center
in theory that mod should not harm the 5200 but i can not be held responsible for your soldering skills or age of the machine or the devices you attach so it is at your risk
when i sold on ebay i had a bunch of joysticks with a throttle and i made special adapters that switched the Y axis with the throttle axis so people could use the little lever as the shifter lever so out there ten 5200 owners have that one
a person could go crazy with all the other options with switches i generally like to keep an adapter simple
but my personal prototype has switches to use button 3 as 1 ,button 4 as 2 ,swap throttle for Y,swap rudder for x
i never use it i just want to plug in my gravis gamepad press the little start button and play digdug
That's an interesting suggestion. I'll put it on my (unfortunately long) to do list. What you say makes me wonder if plugging the 5200 controller/keypad end of your original adapter into the 5200 trackball would have the same effect, just to see what effect it has. Obviously, this would be a little more crowded than the mod you suggested, but, if it works, it would give me an idea if i did the adapter mod properly. This would be nice, if true, since sometimes I about pull my hair out with testing and re-testing the trimmer because the insides of the DB15 breakout connector contacts start to shred after many wires are inserted and removed, especially poking two or three wires into one contact hole at a time, and you think you have contact, but you don't, which can lead to wrong conclusions. But was still a lot of fun overall.