Mac Startup key combinations

[MacTron]

Mac Startup key combinations:

Key Combination	Effect
On Boot
mouse down	Eject removable media ( I think Boot ROMs prior to 2.4f1 excluded the CD drive )
opt	Bring up OF system picker on New World machines - boot to 9 on pre-New World machines
F8	Bring up Mac OS X boot partition selector (DTKs only?)
cmd-period	When OF system picker is active, open the CD tray
cmd-opt	Hold down until 2nd chime, will boot into Mac OS 9 ?
cmd-x (or just x?)	Will boot into Mac OS X if 9 and X are on the same partition and that’s the partition you’re booting from.
cmd-opt-n-d	prevent native drivers from loading (System 7 until 9.x?)
cmd-opt-shift-delete	Bypass startup drive and boot from external (or CD). This actually forces the system to NOT load the driver
	for the default volume, which has the side effect mentioned above. For SCSI devices it searches from
	highest ID to lowest for a partition with a bootable system. Not sure about IDE drives.
cmd-opt-shift-delete-#	Boot from a specific SCSI ID # (# = SCSI ID number)
cmd-opt-p-r	Zap PRAM. Hold down until second chime.
cmd-opt-n-v	Clear NV RAM. Similar to reset-all in Open Firmware.
cmd-opt-o-f	Boot into open firmware
cmd-opt-t-v	Force Quadra AV machines to use TV as a monitor
cmd-opt-x-o	Boot from ROM (Mac Classic only)
cmd-opt-a-v	Force an AV monitor to be recognized as one
c	Boot from CD. If set to boot to X and no CD is present, may boot to 9.
d	Force the internal hard disk to be the startup device
n	Hold down until Mac logo, will attempt to boot from network server (using BOOTP or TFTP)
r	Force PowerBooks to reset the screen
t	Put FireWire machine into FireWire Target Disk mode
z	Attempt to boot using the devalias zip from first bootable partition found
ctl-cmd-shift-power	Reset power manager (with computer off)
shift	(Classic only) Disable Extensions
shift	(OS X, 10.1.3 and later) Disables login items. Also disables non-essential kernel extensions (safe boot mode)
cmd	(Classic only) Boot with Virtual Memory off
cmd-v	(OS X only) show console messages (verbose mose) during boot. Also invokes Safe Mode
cmd-s	(OS X only) boot into single user mode
cmd-opt-c-i	(Mac IIci only) Set date to 20 Sep 1989 to get a graphical easter egg
cmd-opt-f-x	(Mac IIfx only) Set date to 19 Mar 1990 to get a graphical easter egg
cmd-opt-shift-tab-delete	Erase startup disk under 7.1(?)
After display of Happy Mac icon
space	(Classic only) Invoke Extensions Manager
shift	(Classic only) Disable Extensions including MacsBug
shift-opt	(Classic only) Disable exetensions, except MacsBug
ctrl	(Classic only) Break into MacsBug as soon as it is loaded
As Finder Starts
cmd-opt	(whenever Classic Finder sees a new disk) Rebuild Desktop
opt	(Mac OS 9) Do not open Finder windows
shift	(Mac OS X) Do not launch startup items. Do not open Finder windows when launching Finder. The windows’
	states aren’t changed to closed, as they will be reopened if you reboot again.
shift	(Mac OS 9) Do not launch anything from the "Startup Items" folder.

[darthnVader]

Portables:

Power+Applekey: Load the defaults for Open Firmware.

[refinery]

fascinating. i thought I knew my stuff but there's a few things on here i've never even heard of.

[Steve_W]

Nice! Printed and laminated for reference!