1.4 Display Port KVM Switch - Dual Monitor - Two Computer
10-gigbit
The latest firmware for Keychron Q3 Max breaks the ability to enable and disable Nkey rollover. This then breaks the ability to trigger Level1 KVM hotkeys.
This is a fix to a headache that I’ve been trying to fix for awhile now. Posting it here so others can find it.
Keychron firmware 1.0.0 worked fine with the Level1 KVM. Just enable/disable Nkey rollover and the hot keys would work as expected. The problem with 1.0.0 is that the battery life is terrible and keys often double type. The latest 1.1.1 firmware fixes this, but breaks the ability to toggle Nkey rollover so I was unable to use the KVM hotkeys.
I fixed this by forking Keychron’s QMK repo and modifying it. Here are my changes to reenable the toggle for the Q3 Max specifically.
Full disclosure Claude helped since I don’t know C so please let me know if it did something dumb.
According to Claude, the latest firmware enables a sort of just in time Nkey rollover. So When 1-6 keys are pressed, rollover is disabled. But when you press 7 or more keys, the keyboard will automatically enable rollover. Handy to maintain compatibility I guess, but it breaks the KVM hot keys for whatever reason.
My fork disables the auto rollover and returns it to a manual toggle. Now my keyboard shows up in launcher.keychron.com with firmware 1.1.1 and all its improvements while keeping the 1.0 Nkey rollover functionality.
Again Claude did almost everything, but I’m not skilled enough to verify its explanation. I mostly understand what code changes it made, but please let me know if it can be improved.