I want to try installing Ubuntu on an Apple Macintosh iBook (Dual USB) from 2001, just to see if it can be done.

The iBook's CD drive is unable to read Ubuntu PowerPC 12.04 CDs that I've burned for it. It boots to a text display which then says "Can't read boot blocks", or which gives me read errors then dumps me at a yaboot prompt. I'm guessing the drive is too old to read CD-R media or else it's damaged, so I want to try booting the Ubuntu installer from a USB flash drive (8GB).

I understand that I need to format the USB flash drive partition as "Apple_Bootstrap". How do I do this? I can't find mac-fdisk in any repositories, and gnu-fdisk and parted both want me to enter a filesystem type but don't have Apple_Bootstrap in their lists of type codes.