People discover keyboard shortcuts in a couple of ways. A rare exception is the Esc (Escape) key, which people can use as a shortcut to invoke a cancel action in various contexts. Start up from an OS X startup volume when the Mac would otherwise start up from a non-OS X startup volume.Įject (⏏), F12, mouse button, or trackpad buttonĮject removable media, such as an optical disc. Most keyboard shortcuts consist of a combination of keys: a single primary key and one or more of the modifier keys (Command, Shift, Control, and Option). Reset NVRAM. Release the keys after you hear the startup sound again. Start up from OS X Recovery over the Internet. Start up from a NetBoot server using the default boot image. Key commands that map to known system events (such as Cut, Copy, and Paste) are automatically routed to the appropriate responder methods. The system always has the first opportunity to handle key commands. Start up from a compatible NetBoot server. Key command sequences are generated only for devices with an attached hardware keyboard. Start up to either Apple Hardware Test or Apple Diagnostics over the Internet. Start up to either Apple Hardware Test or Apple Diagnostics, depending on which Mac you're using. Start up from a bootable CD, DVD, or USB thumb drive (such as OS X install media). The links below point to other support documents on Apple's website. I'm betting many of you don't know them all, either, so here they are. I was personally familiar with these and several others, but it turns out there are 15 total combinations, thanks to a KnowledgeBase article Apple posted. Command-S is for 'single-user mode,' which essentially means booting to the command line. Shift key, for instance, starts your Mac in Safe mode, and C (or c) starts up from a bootable CD, DVD, or thumb drive. Your Mac and OS X have a variety of startup keys and key combinations you can use to affect how the device starts up.

Apple command key