Key Combination Effect
On machines with a power key (desktops)
power Bring up dialog for shutdown, sleep or restart (see next table)
cmd-ctrl-power Unconditionally reboot (sometimes referred to as “control flower power” to easily remember) (dirty reboot - may corrupt disk)
ctrl-cmd-opt-power Fast shutdown
cmd-power Bring up debugger (if debugger installed). Really old macs (mac ii era) needed Paul Mercer’s debugger init to do this, then it got folded into the firmware, around 040 timeframe.
cmd-opt-power Put late model PowerBooks & Desktops to sleep
cmd-opt-ctrl-power (PowerBook 500) Reset Power Manager
shift-fn-ctrl-power (PowerBook G3, G4) Reset Power Manager
On machines without a power key (laptops)
ctrl-eject Bring up dialog for shutdown, sleep or restart (see next table)
cmd-ctrl-eject Unconditionally reboot
ctrl-cmd-opt-eject Fast shutdown
cmd-eject Bring up debugger (if debugger installed). Really old macs (mac ii era) needed Paul Mercer’s debugger init to do this, then it got folded into the firmware, around 040 timeframe.
cmd-opt-eject Put late model PowerBooks & Desktops to sleep
On all machines
cmd-opt-esc Force quit current app
cmd-shift-0 Put late model PowerBooks & Desktops to sleep No longer work in OS X. On Macs with three floppy drives (Mac SE) they eject the third floppy disk.
cmd-shift-1 or 2 Eject internal or external floppy. Not sure which is which on dual floppy machines (Mac SE, Mac II, etc.)
cmd-shift-3 Screen shot
cmd-shift-4 Abstract user defined area screen shot (hold control while selecting to direct it to the clipboard on Mac OS 9)
cmd-shift-capslock-4 (Classic only) User selectable window screen shot
cmd-ctl-shift-3 Screen shot to clipboard
cmd-ctl-shift-4 Abstract user defined area screen shot to clipboard
cmd-ctl-shift-capslock-4 (Classic only) User selectable window screen shot to clipboard (classic only)
cmd-tab Switch apps (possible to change key in Mac OS 8-9)
cmd-shift-tab Switch apps in reverse order
cmd-space Switch keyboards/script systems (if more than one is installed)
cmd-opt-space switch through all keyboards in keyboards menu
opt-f3, opt-f4 or opt-f5 bring up the system preferences (Mac OS X only - maybe powerbooks only? only if system preferences isn’t already running)
cmd-f1 toggle between video mirroring and extended desktop mode (works on Ti Powerbooks)
opt-f1 open the displays preference (10.2 and later)
cmd-f2 auto-detect a newly-connected display (works on Ti Powerbooks)
opt-f2 open the displays preference (10.2 and later)
opt-f3, f4, or f5 open the Sounds preference (10.2 and later)
opt-f8, f9, or f10 open the Keyboard and Mouse preference (10.2 and later)
f12 Eject CD/DVD (must be held down on 10.1.2 or later). If the device can be dismounted, it is. If not, nothing happens.
f14 dim display (cubes/g4 iMacs/others?)
f15 brighten display (cubes/g4 iMacs/others?)
cmd-ctl-shift-0 Spin down HD (when possible) on machines running OS 9
cmd-` cycle through current application’s windows (Mac OS X 10.2 only?)
cmd-~ cycle through current application’s windows (reverse order) (Mac OS X 10.2 only?)
opt-"Empty Trash" Emptry trash without locked file or contents summary alert. Empties locked items, as well
cmd-opt-D (Mac OS X only) toggle dock
cmd-opt (when opening chooser) (Mac OS 9 only) rebuild chooser cache of printer driver information