os/x11/ XInput
Floating
On my T410:
$ xinput
⎡ Virtual core pointer id=2 [master pointer (3)]
⎜ ↳ Virtual core XTEST pointer id=4 [slave pointer (2)]
⎜ ↳ SynPS/2 Synaptics TouchPad id=10 [slave pointer (2)]
⎜ ↳ TPPS/2 IBM TrackPoint id=11 [slave pointer (2)]
⎣ Virtual core keyboard id=3 [master keyboard (2)]
↳ Virtual core XTEST keyboard id=5 [slave keyboard (3)]
↳ Power Button id=6 [slave keyboard (3)]
↳ Video Bus id=7 [slave keyboard (3)]
↳ Sleep Button id=8 [slave keyboard (3)]
↳ AT Translated Set 2 keyboard id=9 [slave keyboard (3)]
↳ ThinkPad Extra Buttons id=12 [slave keyboard (3)]
and
xinput float 9
disconnects the built-in keyboard from the master, and
xinput reattach 9 3
reconnects it.