Have a powerbook g4 that came with ubuntu 12.4 installed. Foolishly i updated to 16.4 and have not been able to run th unity gui or any other. I have spent about two weeks researching which has been very educational and have tried many things non of which have worked. I think the problem is something to do with DISPLAY . I have learned about open firmware but cant get the machine to boot from cd or usb even though i have followed a number of tutorials. Currently I have access to 16.04 command line so can learn a lot but i would still like a gui. (Log in to hide this advertisement) Can anyone help as to where i can start...restart.