Posts: 2788 from 2003/3/5
The problem with USB boot is that Mac's OpenFirmware does not support USB in its Alt-key boot menu. Other than that it should work provided you use the Apple Partition Map for the disk.
As for multi-boot, the steps are mostly the same. I'd recommend creating 3 new partitions under Linux. You will then have to finish partitioning with MorphOS booted from CD. First partition (64-128MB) needs to be set to HFS (not HFS+!) and formatted. Remaining two should be set to SFS - but all of that is in the dual boot guide.