So, in order to upgrade to Dapper you need to make sure that the correct repositories for emc2 are specified.
Change all instances of the word "breezy" in /etc/apt/sources.list with "dapper":
sudo cp /etc/apt/sources.list /etc/apt/sources.list.old cat /etc/apt/sources.list | sed s/breezy/dapper/g > /tmp/sources.list sudo cp /tmp/sources.list /etc/apt/sources.list
Now, there should be lines in your /etc/apt/sources.list that say:
deb http://www.linuxcnc.org/emc2/ dapper emc2.1 deb-src http://www.linuxcnc.org/emc2/ dapper emc2.1(If they end in emc2 instead of emc2.1, then you are still using emc 2.0) We recommend changing 2.2 unless you need to keep using emc 2.0.x or 2.1.x for some specific reason.
Next we begin the arduous, bandwidth-wasting process of upgrading online. Don't even think about doing this on a dialup connection.
sudo apt-get update sudo apt-get dist-upgrade
This should automatically install the new version of the kernel, since emc2 depends on it. When the computer is finished upgrading - a few hours on my dsl connection - you must reboot to start the new kernel.
If it asks you about overwriting kernel modules, say "no" you don't want to stop the installation. (does it actually ask this?)
If you will be compiling from source, you should now remove the old kernel packages so that autoconf doesn't get confused and pick the wrong realtime directory or kernel headers:
sudo apt-get remove linux-image-2.6.12-magma sudo rm -r /usr/realtime-2.6.12-magma sudo dpkg --purge linux-image-2.6.12-magma sudo dpkg --purge linux-headers-2.6.12-magma sudo rm -r /usr/lib/modules/2.6.12-magma
That's all there is to it!