bobw
The Late: SuperMacMod
From Macosxhints.com;
If your Mac is booting to a folder with a question mark instead of Mac OS X, and happens that you do not have a System CD with you from which to boot and fix your startup disk, here is a trick that may bring it back to normal. It should also work for most new Macs. Boot to Open Firmware by pressing Alt+Command+O+F on boot. At the prompt, type the following two lines:
set-defaults [hit Enter]
boot hd:,SystemLibraryCoreServicesBootX [hit Enter]
Hopefully your Mac will boot to OS X or if the trick doesn't work, to a white screen with an error signal instead of the Apple logo, just switch off the box and try the commands again. Remember to re-set your startup disk to the Mac OS X folder in the Preferences -> Startup Disk after you get running again!
If this trick doesn't make your Mac come back, you may want to go and read this document,
http://www.bombich.com/mactips/openfirmware.html
and additionally this info on Open Firmware by Apple
http://developer.apple.com/technotes/tn/tn1061.html
Finally, this one is a quick info page for OpenFirmware, very clear and useful.
http://www.firmworks.com/QuickRef.html
If your Mac is booting to a folder with a question mark instead of Mac OS X, and happens that you do not have a System CD with you from which to boot and fix your startup disk, here is a trick that may bring it back to normal. It should also work for most new Macs. Boot to Open Firmware by pressing Alt+Command+O+F on boot. At the prompt, type the following two lines:
set-defaults [hit Enter]
boot hd:,SystemLibraryCoreServicesBootX [hit Enter]
Hopefully your Mac will boot to OS X or if the trick doesn't work, to a white screen with an error signal instead of the Apple logo, just switch off the box and try the commands again. Remember to re-set your startup disk to the Mac OS X folder in the Preferences -> Startup Disk after you get running again!
If this trick doesn't make your Mac come back, you may want to go and read this document,
http://www.bombich.com/mactips/openfirmware.html
and additionally this info on Open Firmware by Apple
http://developer.apple.com/technotes/tn/tn1061.html
Finally, this one is a quick info page for OpenFirmware, very clear and useful.
http://www.firmworks.com/QuickRef.html