Synaptics T1004 based touchpad to PS2 port

I was having kind of a slow day here at the office so I thought I would start sorting through some old boxes of junk we had lying around and stumbled upon a few laptop touchpads cowering at the bottom of a box labeled ‘Misc Laptop Parts’ (fancy that). Remembering that some years ago I had read most touchpads use the PS2 protocol I rescued them from their cardboard prison and decided to see if I could make one work with my computer. I googled and googled but could not find any good pin out info for any of the touchpads I had, most people are recommending trying this with the Synaptics flavor of touchpad, I had one Synaptics and the rest were Apls. I figured I would follow the crowd and play with the Synaptics one and condemned the Apls pads back to their confining cardboard container. Synaptics does have some very informative information on their website by means of a PDF file containing more information than one could ever want to know about thouchpads but no pin outs at least not for the model I held in my eager little hands. This is not really a tutorial on how to do this mod I just wanted to share some of the info I had found, I figure if you are even thinking about attempting this mod you should have some knowledge of electronics, soldering and general tinkery about you, if not, buy a mouse. I gave up on finding the pin outs for my specific touchpad and decided to look into the controller chip on the damn thing. It would seem that Synaptics really only use 2 chips the T1002 and the T1004, the one I possessed was the T1004 and Synaptics are very tight lipped about the pin outs for this device. I broke out the old multi-meter and started to trace some of the tracks for this chip. After an hour or so, a few trial and error attempts, two cups of coffee and a cigarette I finally figured out the important bits, it is true that a picture speaks a thousand words so have a look at the picture (if you click on it it should enlarge) and it should give you a good start in doing this. Trace back tracks from the chip to a good point to attach your wires, remember though this doesn’t have to be the actual connector, mine had some nice gold test points on the PCB that I used. I stopped tracing tracks after I had the touchpad working so I don’t that the pin out info on the buttons, but to be honest you don’t really need the buttons, left click is just a tap on the pad and you can set right click to be a hot region somewhere on the touchpad (I used bottom right corner). So there you go, hope it helps someone and remember if you blow something up it isn’t my fault.

This is where I got the pin out info for the PS2 port

http://burtonsys.com/PS2_keyboard_and_mouse_mini-DIN-6_connector_pinouts.html