What worked for me on a Cube G4 was the following (based on Joshua's advice):
- I formatted my USB thumb drive in Disk Utility with Apple Partition Map and a MS-DOS (FAT) partition.
diskutil list should bring something like this up:
- Now let's for the sake of it nuke the FAT32 partition:
w and exit
CTRL+C. The entire process should look something like this:
The deeply cleansed disk should appear like so (
- Now we can copy over the Mac OS X 10.5 Leopard ISO with dd:
sudo dd if=/<path to iso file>/<name of iso file> of=/<path to usb stick> bs=32768 conv=notrunc,noerror,sync. It should be something like this:
- Depending on your stick, this might take upwards of a few hours (even with a badass USB3 one!). At the end,
diskutil list should show something like this:
Plug this into your G5 Cube, and, at boot, press both ALT keys (theoretically one should work but with my wireless keyboard the both button approach works best)
You'll get a very primitive version of the present day Boot Selection screen, WHICH ONLY WORKS WITH A MOUSE ! There you'll find the USB Stick and be able to boot from it, and install as if it were a very speedy and silent DVD drive :)
For those wishing to install Mac OS X 10.4 Tiger, the ISO floating around for that seems to contain a very small Apple_Driver_ATAPI partition (disk2s2 in step 4), a few KB instead of half a GB. This unfortunately seems to be incompatible with steps 1-6..
The workaround is the following: prepare a 10.5 Leopard USB stick, and overwrite the Apple_HFS partition with the Apple_HFS partition from the 10.4 Tiger disk:
Proceed with creating a Leopard 10.5 stick as in steps 1-4
Mount the OSX 10.4 Tiger image; it should look something like this:
dd, copy over the Apple_HFS (disk3s3 or diskNs3) partition OVER the Apple_HFS (~7GB) on the stick. This will leave you with a stick having the ATAPI driver from the Leopard DVD disc, but the OS image of the Tiger disc. Through this method, I got it to show, and managed to install Tiger alongside Leopard xD. On my end, it looks like this:
For those wanting to install 10.3 or lower Unfortunately, I haven't found any way to get those to boot off of a USB device (not initially though).
To install 10.3 / 10.2 / 10.1 / 10.0, burn the CD1 image onto a disk, which you will have to be reading through the on-board IDE cable (connecting a USB cd-rom doesn't cut it, not USB allowed !). You'll install as per usual, pressing alt (both of them in case of the cube) at bootup, selecting the CD, installing ...
You'll at some point be asked to insert the 2nd disc - those you may prepare the same as a Tiger installation: make a Leopard disc, and overwrite the 3rd partition (the Apple_HFS one that occupies the most space) with the Apple_HFS partition of the CD2 of the pre 10.4 OS you're installing. This time the system will accept it and continue installing from the USB device.