Mac startup keys

[This document is obsolete: Please consult Magical Macintosh Key Sequences by Dave Polaschek.]

When a Macintosh is powered-up or Restarted ("booted"), various pieces of Mac ROM and System software examine the keyboard, and take special actions if certain keys are held down. This page summarizes the actions.

Booting involves several phases; startup keys take effect at different times depending upon the phase. Sometimes the same key has a different effect depending upon which phase it is sensed. Generally, you should hold the indicated keys down until the desired action takes place.

Boot ROM

Command-Option-P-R Zap PRAM (double boot)
R Force PowerBook to reset the screen
Command-Option-A-V Reset AppleVision Display (1.5.2 or later)
Command-Option-T-V Force Quadra AV (only) to use TV as a monitor
Command-Option-X-O Force Mac Classic (only) to Boot from ROM
Mouse button Eject Floppy, then boot from SCSI
Command-Option-Shift-Delete Bypass the device that is selected in the Startup Disk control panel; boot from the first bootable device other than that.
Command-Option-Shift-Delete-# Boot from a specific SCSI ID, where # is 0 through 6
C Boot from internal CD-ROM (Most late model Macs)
N Boot from network (iMac and later models)
D Boot from the internal hard disk if the default boot device has been set to something else
Z Boot from an internal Zip drive
O-F Access Open Firmware (on G3 and later models)
T Boot into FireWire Target Disk mode (on certain FireWire-equipped Macs)

Upon appearance of the happy face, let go of any boot keys you may have needed, then immediately press any keys you need to control ...

Mac OS System startup

Control Invoke MacsBug upon startup.
Option In Mac OS 9.x, on a startup disk having multiple system folders, invoke dialog to choose System Folder.
Command Boot with Virtual Memory off
Shift Disable all Extensions and Control Panels. Release Shift when the message "Extensions disabled" appears in the welcome box.
Space Open extension manager before loading Extensions or Control Panels. Release the Space bar when the Extensions Manager displays its screen.

Holding the Shift key early in the boot sequence disables all Extensions and Control Panels. Individual Extensions and Control Panels may disable themselves upon seeing the Shift key later in the boot sequence, but the timing for this is difficult to achieve! Upon loading, an Extension or Control Panel is supposed to display its icon in the "icon parade." If the icon is displayed at boot time, but the Extension or Control Panel disables itself because the Shift key is held or some error condition is detected, it is conventional for a red X to be drawn over its icon.

Immediately upon the appearance of the (blank) menu bar, press any keys you need to control ...

Finder startup

Command-Option Rebuild Desktop
Option Don't open Finder windows
Shift Disable "Startup Items"

After startup

Lots of Finder shortcuts are documented in the online Finder Help. (p.s. Don't delete that file: Certain Apple installers refuse to function unless that file is in its proper place.)

Command-Shift-1 (or 2, or 0) Eject a Floppy Disk [FKEYs]
Command-Option-ESC Force current app to quit.
Command-POWER Invoke the debugger (if MacsBug is installed) - G to return to interrupted code

Restart, Sleep, Shutdown

If you have a Power key, it is at the top of your keyboard, at the center or on the right hand side; it carries an incused triangle symbol.

POWER Present Restart, Sleep, Shutdown dialog - key R for Restart, S for Sleep, ESC for cancel, or Return for Shutdown.
Control-Command-Option-POWER Fast Shutdown
Command-Option-POWER Put late model PowerBooks & Desktops to sleep
Control-Command-POWER Unconditional, forced reboot (the "three-finger salute")

This document may be freely distributed for noncommercial purposes, provided that it is distributed unmodified and in its entirety, and that this copyright notice remains intact.

Charles Poynton - Mac
Copyright © 2001-07-15