The current build of the installation manual lists links for download files in section
4.2.3. Where to Find Installation Files .
These link are incorrect, at least for powerpc (which is the version of the manual I was looking at). The links are patterned like
Instead, the actual directory structure in the archive is like
Actually, the entire section of the manual on which files are available, and how to choose them, is out of date for powerpc. Probably Sven could point to clues about that.