Thursday March 23, 2017

Arcade Trackball Mouse Hack

Step 5: Identifying Connection / Hack Points
The connection points need to be identified on the RX (receiver) solder points.  In my case each of the receivers had hooked into 4 solder pads.  I was able to trace two of these to power & ground.  The remaining two were then identified as the 2 phases for each receiver.  The only thing I tapped into on one of the transmitter solder pads was +5v for power, but this could have been tapped into anywhere on the board.

Your mouse circuit board will likely look different.  If your receiver (RX) solder points only have 3 solder pads, then two of those pads should be for the phases and the remaining is likely power.  You can identify this by following the traces from the solder pads.  If they lead to the microcontroller IC, they should be the phases and remaining point(s) are power/ground.  You can also use your multimeter on the ohm or continuity setting to verify the remaining solder pad(s).

Connection Points
Picture: Connection points for trackball wires

Step 6: Wiring It Up
You have a few options here.  You can cut the molex connector off of the wire harness of the trackball and solder the trackball's wires directly to the mouse board.  Another option if you want to preserve the trackball connector is to create your own wire harness for the mouse circuit board.  That's the option I took.  The parts don't cost a lot but there is a special crimp tool needed for the molex pins that can run you an additional $15-20 if you don't already have one.  So depending on how much you care about not preserving the original molex connector on the trackball you can decide if it's worth spending the extra money to create a mating harness for the mouse circuit board.

Below is a picture of a molex pin crimped onto a wire hooked into the mouse.  Again this step is optional if you want to preserve the connector on the trackball itself.

Molex Pin
Picture: Female 0.093" molex pin crimped onto wires from the mouse

Picture: Horizontal phases, Vertical phases, +5v and GND wired

In the picture above, wires have been soldered onto the two horizontal phase inputs, the two vertical phase inputs, +5v on the board and a GND solder point on the back of the board.  Don't pay attention to the wire colors if you've cut the trackball's molex connector off and are soldering the trackball's wires directly to the mouse.  My wire colors are for the custom wire harness I built (see wire references below).

Once all of the wires were soldered to the board & molex pins attached, I pushed the pins into the new molex receptacle (part 03-09-1061).. first matching the power and GND up with the trackball's power and GND locations on the male connector.  Then "guessing" the wires for the horizontal and vertical phases and inserting those pins into the receptacle.  If you cut the molex connector off the trackball, your wires would be directly soldered to the mouse circuit board.  If you get the two horizontal (or vertical) phases mixed up, moving left or right will just be backwards of what it should be & you can reverse the wires.

My Betson Trackball has these wire colors:

Red = +5v
Black = GND
Yellow = Horizontal Phase 1
Green = Horizontal Phase 2
Brown = Vertical Phase 1
Blue = Vertical Phase 2

Note: Your trackball may differ so best to Google for the pinouts

The wire harness going into the mouse has these wire colors:

Orange = +5v  (hooks to red wire on trackball)
Black = GND  (hooks to black wire on trackball)
Brown = Horizontal Phase 1 (hooks to yellow wire on trackball)
Green = Horizontal Phase 2 (hooks to green wire on trackball)
Blue = Vertical Phase 1 (hooks to brown wire on trackball)
White = Vertical Phase 2 (hooks to blue wire on trackball)

Step 7: Finishing & Testing
I verified the pin connections with the continuity test on my multimeter.  Best to do this to find any shorts and verify connections before hooking it up to an expensive computer.  Once I was reasonably sure the connections were correct, I connected the PS/2 cable to the computer.  At first, it didn't work -- but that's where Murphy's law came in.  After testing with my multimeter I realized I wasn't getting +5v power to the trackball and found the +5v wasn't connected to the mouse at the right solder point.  Once that was connected, the trackball worked -- but then would stop working.  Turns out that the ground wire I soldered onto the mouse had bad spot in the wire (broken connection).. so I had to rewire the ground wire.  I also had to switch the horizontal phase wires since moving the trackball left would make the mouse cursor go right & vice-versa.

Conclusion / To Do

The completed trackball hack is shown below & it works!  I can move the computer's mouse cursor with the trackball.  What I should probably do is put the circuit board into a small "project case" available from radio shack.. or back into the mouse case it came out of so that it's protected and looks nicer.  Something else you could do as I mentioned is solder wires to the button connections on the mouse circuit board so that you could put the buttons anywhere you'd like.  Just depends if you truly want to use it as a mouse or just want to remap some other buttons in MAME, etc.

Now the hard part is going to be figuring out how to modify the current control panel or build a new control panel so I can fit this into a machine.  My current control panel has no room for a large arcade trackball.. so it seems I've created another project for myself, especially if the wife gets into playing any games that use the trackball!

Completed Trackball
Picture: Finished trackball to mouse hack

Here's some other great links on the subject:

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RE: Where can I buy a hacked mouse
Posted 08/17/11 4:44PM by AceBHound
You might be interested in an "OptiPac" from Ultimarc for around $39. That would allow you to hook up your arcade trackball wires directly to the terminal block connections on the OptiPac and if your trackball had a slightly different wiring configuration you'd be able to swap wires easily.
Where can I buy a hacked mouse
Posted 08/13/11 8:39AM by Anonymous Techdoser
Where can I purchase a pre-hacked mouse?