Mac OS X Startup Keys

I tried to update to 10.4.9 yesterday, but got an error message, and when booting everything hangs. I haven’t found a good solution yet, but at least I came across a list of useful startup keys, some of them being:

  • C : Forces most Macs to boot from the CD-Rom drive instead of the internal hard drive. Only works with Apple ROM drives and with bootable CD discs.
  • D : Forces the first internal hard drive to be the startup disk.
  • N : Netboot (New World ROM machines only) – Looks for BOOTP or TFTP Server on the network to boot from.
  • R : Forces PowerBooks to reset their screen to default size (helpful if you’ve been hooked up to an external montior or projector!)
  • T : Target Disk Mode (FireWire) – Puts machines with built-in FireWire into target Disk mode so a system attached with a FireWire cable will have that device show up as a hard drive on their system. Very useful for PowerBooks!
  • Mouse Button Held Down : Ejects any mounted removable media.
  • Shift : Disables all extensions (Mac OS 7-9), or disables Login items when using Mac OS X 10.1.3 or later. Also works when booting Classic mode up just like you were using the OS natively.
  • Option : When using an Open Firmware “New World ROM” capable system, the System Picker will appear and query all mounted devices for bootable systems, returning a list of drives & what OS they have on them. On “Old World” systems the machine will simply boot into it’s default OS without any Finder windows open.
  • Space bar : Brings up Apple’s Extension Manager (or Casady & Greene’s Conflict Catcher, if installed) up at startup to allow you to modify your extension set.
  • Command-V : Boots Mac OS X into “Verbose Mode”, reporting every console message generated during startup. Really shows what’s going on behind the scenes with your machine on startup!
  • Command-S : Boots Mac OS X into “Single User Mode” – helpful to fix problems with Mac OS X, if necessary.
  • Command-Option-P-R : Erases PRAM if held down immediately after startup tone. Your machine will chime when it’s erased the PRAM, most people will hold this combination for a total of 3 chimes to really flush the PRAM out.
  • Command-Option-Shift-Delete : Forces your Mac to startup from its internal CD-ROM drive or an external hard drive. Very helpful if you have a 3rd party CD-ROM drive that is not an Apple ROM device.

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alexarje

Alexander Refsum Jensenius is a music researcher and research musician living in Oslo, Norway.