RagingRooseveltAny combination of six keys seems to work fine and IIRC N-key rollover over USB is planned to be implemented in the firmware some time in the future. I have no idea about PS2 compatibility though.
HenryWould it be possible to use two Teensy's, one controlling each side, and bring that up to 12 keys? I would probably require a small bit of modification to the firmware, but it would increase the polling rate for each side as well?