MAC: What is the most recent Cubase to work on an iBook G4?


my MacBook Pro, running C5, is in for repair and I need to rely on my old iBook 1.2 GHz Power PC G4, running OS 10.3.9 to get me through the next week. Will it run C5, if I install it? If not, how about C4? And would I be permitted to download it from Steinberg’s FTP page and use it under my C5 licence?