Thankfully, somewhere about the time the iMac G5 with the ambient light sensor (ALS) was released, Apple tweaked their Open Firmware, which allowed us to boot PowerPC Macs from USB2 drives.
This may work for your needs but I would strongly urge you to proceed with caution as it involves making alterations to Open Firmware.įirst off, I have tried and tried again over the years to boot various PowerPC Macs via a USB2 disk. The text below is copied from the excellent tip at Mac OS X Hints. I've never tested it with a USB optical drive but you might give it a shot none the less. With that said, there are old tricks to making a PowerPC based Mac boot from a USB2 hard drive. PowerPC (G3, G4, G5) Macs only natively supported booting from Firewire devices. I can't say for certain that booting from a USB optical drive wouldn't work but I would be surprised if it did.
