Mac startup key sequences What are the Mac hardwares various startup key sequences? 

On the older Macs, Shift used to be start without extensions, Ctrl-Apple-O-F would boot to OpenFirmware, (but didn't the Intel Macs switch to EFI BIOS's?)

If the shortcut is hardware specific, please note it.
Google is your friend: http://www.jacsoft.co.nz/Tech_Notes/Mac_Keys.shtml




Bypass startup drive and boot from external (or CD): commandoptionshiftdelete
Boot from CD (Most late model Apples): C
Force the internal hard drive to be the boot drive: D
Boot from a specific SCSI ID #. (# is SCSI ID number): commandoptionshiftdelete#
Zap PRAM: commandoptionPR
Boot into open Firmware: commandoptionOF
Clear NV RAM. Similar to reset-all in open Firmware: commandoptionNV
Disable Extensions: shift
Rebuild Desktop: commandoption
Close finder windows (hold just before finder starts): option
Boot with Virtual Memory off: command
Trigger extension manager at boot-up: SPACE
Force Quadra av machines to use TV as a monitor: commandoptionTV
Boot from ROM (Mac Classic only): commandoptionXO
Force PowerBooks to reset the screen: R
Force an AV monitor to be recognized as one: commandoptionAV
Eject Boot Floppy: Hold Down Mouse Button
Select volume to start from: option
Start in Firewire target drive mode: T
Startup in OSX if OS9 and OXS in boot partition: X or commandX
Attempt to boot from network server: N (Hold until Mac Logo appears)
Hold down until the 2nd chime, will boot into 9?: commandoption
OSX: Watch the status of the system load: commandV
OSX: Enter single-user mode (shell-level mode): commandS