Press and hold 'C' during startup
Start up from a CD / DVD that has a system folder.
Press and hold 'D' during startup
Forces internal disk to boot. (If system volume.)
Press and hold 'N' during startup
Attempt to start up from a compatible network server (NetBoot).
Press and hold 'T' during startup
Start up in FireWire Target Disk mode (access through FireWire to a second computer, this computer acts like external HDD).
Press and hold 'X' or '-X' (Command-X) during startup
Force Mac OS X startup.
Press and hold 'Z' during startup
Attempt to boot from first bootable partition (primary drive).
Press 'F8' during startup
Mac OS X boot partition selector.
Press and hold '⏏' or (Eject) [or 'F12' key] or [Command-E] or [Depress Left Mouse Button] during startup
Forces ejection of a CD / DVD.
Press and hold '' (Option) during startup
Allows temporary selection of startup volume through the use of an icon lineup.
Press and hold '' or (Shift) during startup
start up in Safe Boot mode. (Temporarily disable login items and non-essential kernel extensions. Mac OS X 10.2 and later.)
Press and hold '' or (Shift) after startup boot-screen
Press and hold '' or (Shift) after login
Safe login mode. (Disables user login items and non-essential user extensions. Mac OS X 10.2 and later.)
Press and hold '-S' or (Command) - S' during startup
Start up in Single-User mode.
Press and hold '-V' or (Command) -V' during startup
Start up in Verbose mode. (Displays console messages and disables user login items and non-essential user extensions.)
Press and hold '--O-F' or (Command-Option-O-F) during startup
Invokes Open Firmware.
Press and hold '--P-R' or (Command-Option-P-R) during Startup until a second startup sound
Resets Parameter RAM.
Press and hold '--N-V or (Command-Option-N-V) during startup
Resets non-volatile RAM.
Press and hold ' - - - ' or (Option-Command-Shift-Delete) during startup
Bypass primary startup volume and seek a different startup volume (such as a CD, DVD, or external disk).
Press and hold ' - - ' and press the power button or ( Command-Control-Shift-Power) [while computer off]
Resets the power manager state to default.
Press '-⏏' (Control-Eject) or Power button
Brings up the Restart, Sleep, or Shutdown dialog box.
Press '--⏏' (Command-Option-Eject)
Fast sleep. (No confirmation)
Press '---⏏' (Command-Option-Control-Eject)
Fast Shutdown. (No confirmation)
Press '--⏏' (Control-Shift-Eject)
Display off. (Note: Not secure.)