| 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. | |||