Help With Mouse Hack Please

[Vicious Burger]

I have a basic GE rollerball ps2 mouse that i want to hack for use with an atari trackball, and i have a few questions about the connections to make on the circuit board. Correct me if i am wrong with my assumptions !
From what i gather, this type of mouse will work for this. I took a few pics of the circuit board, but it's laid out differently than the other mouse hacks i have seen online, hence my questions. Has anyone worked with the same board as this? The wires to the ps2 plug I assume to leave as they are. I looked online and pretty sure this trackball needs 5v,and that it would get 5v from the ps2 connection

The P1 and P2 wheel sensors (to be removed along with IR1 and IR2) have 3 connecting pins to the board. As there are 3 connections,I think the middle would be for power, and the outer ones for x and y axis connection.(?) If this is the case, where do I attach the black ground wire from the trackball ?

I'd like to have buttons to use with the trackball, but not with the switches on the board, so if I remove those and in their place, solder in wires and run them to separate cherry switches that should work right?


Thanks in advance for any pointers.

The board


Side view of one of the wheel sensors

[darcyp]

here is what i did with my mouse hack.
i removed the wheel sensors (i didnt worry about the ir1 and ir2 but it wont hurt to take them out) and underneath there were 3 connections each, mine were labeled x1, v and x2 for the x-axis. i took the green and yellow wires that were attached to the optical board for the x axis of my trackball and soldered them into x1 and x2 (which goes into which is not important at this point.) this is my first grainy pic. on your mouse the x axis is controlled by p1, so solder to the connections under the p1 sensor. i then took the purple and blue wires that were attached to the y axis optical board and soldered them to y1 and y2 (the connections under your p2 sensor). if when you hook up the trackball and realize that any of the directions are backwards, like the mouse going left when you push right, you will need to switch the two wires for the particular axis that is backwards.
for power, both the x and y axis boards had a red and black wire, the red needed to be attached to 5V, and the black needed to go to ground. i had a usb mouse where 5v and ground are labeled clearly, so i am not sure where you can get this on a ps2 mouse. you can see in the second picture that each color was soldered together and then into the right spot.

[BobA]

Here is a bit more circuit info on the trackball connection and mouse hack.   No pics of mouse thou since they are all different layout but same basic parts.

BobA Mouse Hack

[Vicious Burger]

Thanks BobA and darcyp. Yeah I guess i can plug in the mouse to the PC,then use a multimeter to find a ground because its not marked,not that i can tell anyway. The other connections shouldnt be a problem. Darcyp,I kind of figured i was on the right track with the xy and 5v,you just confirmed it for me , just need to sort out the ground and should be good to go then. Unless anyone else knows the colour combination of these wires ?