3-inch trackball buttons and Batocera setup

Useful Answer

The button labels sometimes included with arcade parts are often for general arcade encoder boards, not the 3-inch trackball hardware itself.

The 3-inch trackball assembly has these useful connections:

• Standard mouse buttons: left click, right click, and middle click.
• Horizontal disabler: a hardware-level axis lock. When held, it disables left-to-right movement so the user can focus on vertical motion.

The horizontal disabler does not send a separate computer command. It changes the trackball's physical behavior at the hardware level.

If the customer is using Batocera on a Raspberry Pi:

1. Enable the Optical Device setting in Batocera Game Options so movement is recognized.
2. Map a Hot Key button, because Batocera normally needs Hot Key + Start to exit games.
3. For games such as Missile Command, use the trackball for mouse-style aiming and map the cabinet buttons to the game's launch points in emulator settings.

A short delay before the Pi recognizes the trackball can be normal on Linux while the USB bus rescans.

Source Context

The customer had a 3-inch USB trackball for a Raspberry Pi 5 / Batocera cabinet and asked what the extra button labels meant. Support clarified the mouse-button and horizontal-disabler behavior, then gave Batocera optical-device and hot-key mapping guidance.