How-to- Boot commands for Mac OS X

How-to: Boot commands for Mac OS X
While you cannot run any code from Terminal or otherwise to set an order of boot devices, you can easily control where your Mac boots via keyboard commands. The following key combinations can be held as your Mac is powering on:Boot to external hard drive: Command + Option + Shift + DeleteBoot to a bootable CD: CChoose start-up volume: OptionSafe-boot mode: Shift (Note: Disables nonessential and login applications)Verbose mode: Command + VSingle-user mode: Command + STarget disk mode: T (Note: Only for FireWire Macs)NetBoot (from a network server): NReset PRAM: Command + Option + P + R (Note: Hold until second chime)Reset NV RAM: Command + Option + N + VBoot to open firmware: Command + Option + O + FForce eject (CD/DVD): Click Mouse Button and HoldNot all these functions work with every version of Mac OS X or with every hardware upgrade, but they are the most common. Do you have any boot commands not listed here that you use? Let us know in the comments!