Trackball Mouse Hack problem

[cellar]

I'm trying to build a controller using using an Ultimarc 2" trackball and a PS/2 mouse hack. I read all the almost all the tutorials I could find and using a Logitech mouse (it was, if I remember correctly) tried to make it work. Then I read another tutorial that mentioned Logitech mice don't work for some reason.  So I ended up finding a PS/2 mouse made by Compaq in a second hand store (non-optical mice are hard to come by these days!!). Come back home, de-solder everything again and resolder the connections to this mouse. It still doesn't work right.

On both mice the buttons work fine but the trackball doesn't move the cursor. I even tested the Compaq mouse and it worked fine before I started hacking away at it. I have followed the wiki tutorial to the letter, tested for power and gnd at the trackball, made sure that there are no open connections, checked and rechecked everything multiple times.

Is the Compaq mouse a re-branded Logitech?
Am I missing something?
How come it seems only I can't get this mouse hack thing done right?
Can anyone help me to figure this out?
Do I really have to buy an Optipac?

Sorry, but I find myself to be frustrated over this.

Any help will be great!

[Cananas]

I found this old e-mail that can help you with the mouse hack:

-----Original Message-----
Sent: 04 March 2006 19:28
To: andy@ultimarc.com
Subject: Hi/Lo Plarity with Ultimarc Trackball 

Hello, Andy, I have a pair of Spinners and a mouse hack from Oscar. They work well.
I am trying to connect your trackball to this mouse hack, but it seems that this mouse pcb requires a high polarity device, and your trackball (i think)is low polarity.

So, I had a look and I saw that the oscar sensor pcb had two more resistors that yours. Both are 1K, and are connected between +5V/X1 and +5V/X2. Could I put this resistor on your PCB?. I think yes, but I want your opinion.

BTW, In your web page the resistor in your sensor pcb is 220 Ohm, but in the sensor pcb of the trackballs is a half: 110 Ohm. Is that correct?

Thanks for your patience,

Carlos

Carlos, Yes you would need to add those pull-up resistors for it to work.
The other resistor is in the LED circuit on the trackball board, and the value just controls the LED brightness. On the trackball PCB the LEDs are inseries hence the different value.

Andy

[cellar]

Thank you very much. I hooked up 4 resistors (2 for each axis) and it worked like a charm.
Maybe this should be a side note in one or two tutorials!

Again thank you!!!!