Maria’s Guides

A list of shortcut keys you can use at startup.

There may be times when you want to alter the way your computer starts up. These shortcut keys will do the job.

C

Holding down the C key as your computer starts tells it to look at the CD/DVD drive for a startup disc. If it finds one, it will start from that.

Keep in mind that a startup disc must have a valid System folder for your computer. A good candidate is always the System Software or Restore disc that came with your computer or an installation disc for the latest version of Mac OS.

Option

Holding down the Option key at startup should display a plain screen with buttons representing the available startup disks. Choose the button for the startup disk you want to start from that disk. Keep in mind that this doesn’t work on all Macs.

Command-X

Pressing Command-X right after the startup tone on a computer with both Mac OS X and Mac OS 9 installed will start using Mac OS X. As you can imagine, this feature is only supported on computers that support Mac OS 9 — otherwise why would it be installed?

T

Holding down the T key as your computer starts starts it in Target Disk mode. To take advantage of this feature, the computer should be connected via Firewire cable to another Mac OS computer that is already running. When the Target Disk mode computer starts, its hard disk appears on the other computer’s desktop and can be accessed like any other disk. The Target Disk computer cannot be run like a regular computer until it is restarted with Target Disk mode disabled.

If you know in advance that you want to start a computer in Target Disk mode, you can click the Startup Disk Mode button in the Startup Disk preferences pane, shown here. This immediately restarts the computer in target disk mode.

Shift

If you press and hold the Shift key (either one) right after the startup tone and release it when you see the spinning gear progress indicator, you’ll start the computer in “safe mode.” This loads only essential Mac OS X software. This is useful for tracking down software conflicts, but your applications may not work correctly until you perform a normal restart.

If you press the Shift key (either one) after clicking the Login button at the login screen, you prevent login items and Finder windows from opening when logging in. This can speed up the login process and prevent unwanted applications from starting up.

Left Shift

Holding down this key as the spinning gear progress indicator appears onscreen disables automatic login for the current session. This is handy if automatic login is set up for a user account but you want to go directly to a different user account.

Mouse Button

Okay, so it isn’t a shortcut key. But if you hold down the mouse button as the computer starts, it will eject any removable discs. This is a good trick if your computer insists on starting from a CD that you can’t otherwise eject.

Command-Option-P-R

This combination of keys at startup will reset parameter RAM. Hold them down until you hear the startup tone at least twice. You might want to reset parameter RAM (or PRAM) if you’re having network related problems. You can learn more about PRAM in Mac OS X in the “Mac OS X: What’s Stored in PRAM?” article on Apple’s Web site.

A Few More Seldom-Used Shortcuts

Here are a few more startup shortcuts that the average user will probably never use. But since they exist, I thought I’d list them for reference.

• N starts the computer from the default NetBook disk image. Of course, you need a NetBoot disk image for this to work. (Anyone out there using NetBoot? If so, leave a comment here to tell us why.)
• V starts the computer in “verbose mode,” which displays detailed status messages.
• S starts the computer in “single user mode,” which enables you to troubleshoot the computer using Unix commands.

Page References

Mac OS X 10.5 Leopard: Visual QuickStart Guide includes more information about these topics:

• Startup Disk preferences pane and Target Disk Mode, pages 581-582
• Login Items, page 511
• Ejecting discs, page 105