OS X El Capitan: The Missing Manual

Startup Keystrokes

Startup Keystrokes

Keys to Hold Down	Effect
C	Starts up from a CD or DVD
N	Starts up from a network server
R	Resets the laptop screen
⌘-R	Starts Recovery Mode
T	Puts the Mac into FireWire or Thunderbolt Target Disk mode
Option	Shows icons of all startup disks and partitions, so you can choose one for starting up
Shift-Option-⌘-Delete	Starts up from external drive (or CD)
Option-⌘-P-R	Zaps the parameter RAM (PRAM) (hold down until you hear the second chime)
⌘-V	Shows Unix console messages during startup, logout, and shutdown
⌘-S	Starts up in single-user (Unix command-line) mode
Mouse down	Ejects a stuck CD or DVD
6 and 4 keys	Starts up in 64-bit mode
Shift	Just after you hear the startup tone: Starts up in Safe Mode (Safe Mode (Safe Boot))
Shift	Just after logging in: Prevents Finder windows and startup items from opening (they’ll return the next time you start up)

In the Finder

⌘-space	Opens Spotlight search box
,	Expands or collapses a selected folder in list view
Option-	Expands a folder in a list view and all folders inside it
Option-	Collapses a folder and all folders inside it
⌘-	Opens parent folder
Shift-Option-⌘- ...