> For the complete documentation index, see [llms.txt](https://docs.stenoob.com/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://docs.stenoob.com/toggle-protocol.md).

# Toggle Protocol

<figure><img src="/files/M9nBq9Jmvt63ibCpksk3" alt=""><figcaption></figcaption></figure>

The Pro 3 keyboard supports both Gemini and TX Bolt protocols but is in Gemini by default.&#x20;

**How to toggle**

1. Plug in the keyboard.
2. Press and hold **S (both left S keys) + D + Z** together for \~5 seconds. (Red keys in image above).
3. Watch the LED next to the USB port:
   1. Pro 3
      * **Rapid Green Blinking** = **TX Bolt**
      * **Slow Green Blinking** = **Gemini PR**
      * After 5 seconds, the LED returns to a **solid green** status LED.
   2. **Pro 4**
      * **Green** = **TX Bolt**
      * **Purple** = **Gemini PR**
4. Release the keys once the indicator confirms the selected protocol.
5. The keyboard remembers the selected protocol even after it is unplugged.
6. Repeat the same key chord at any time to switch protocols again.

#### Compatibility

| Protocol      | Software                          |
| ------------- | --------------------------------- |
| **Gemini PR** | digitalCAT, Eclipse, Plover       |
| **TX Bolt**   | Case CATalyst, digitalCAT, Plover |

#### Tips

* Only one application can access the COM port at a time. Close other steno software before connecting.
* If the indicator doesn't change, continue holding the key chord until it does, then release.