Apple has released PowerBook Firmware Update 4.2.9 for 550MHz and 667MHz PowerBook G4s running Mac OS 9.1 or later (users of Mac OS X must start up from a Mac OS 9.1 or later partition or drive). The new version adds improvements to FireWire target disk mode when running Mac OS X, improves starting up on systems with 1GB RAM and enables netbooting over Gigabit Ethernet.