Someone
public unlisted text v1 · immutableFrom the Ubuntu Menu System > Administration > Synaptic Package Manager
Go to Settings > Repositories > Other Software
Add
deb http://buildbot.linuxcnc.org/ lucid master-rt
deb-src http://buildbot.linuxcnc.org/ lucid master-rt
Open a terminal and say
sudo apt-get update
sudo apt-get install linuxcnc