Dr. Mac's OS X Tip-of-the-Day  

This tip comes to you direct from an Apple technical support rep who shall -- for his or her own job security -- remain unnamed. This person explained that there was a little-known secret she always recommends to users PRIOR to attempting to zap their PRAM.

What is this magical technique? Resetting the Open Firmware. It's kind of like zapping the PRAM but different. To do it, shut down your Mac, then press Command-Option-O-F as you start it back up. You can release the keys when you see a white screen that says "Welcome to Open Firmware." At the Open Firmware prompt, type "reset-all" (without the quotation marks, of course) and then press Return or Enter.

To exit Open Firmware, type "bye" or "mac-boot" (no quotes).

While doing some research on this technique, I found an Apple Tech Note with another Open Firmware command that could come in handy someday. If you type "eject cd" (no quotes; followed by Return or Enter) at the Open Firmware prompt, your Mac will often spit out a recalcitrant CD that won't come out any other way.

I had never tried this technique before last week, but the aforementioned support technician swears that it often solves problems when other troubleshooting techniques fail. I've tried it several times and have suffered no ill effects. But since these are more or less undocumented commands, be careful if you decide to give it a try.

(If you know of other uses for this technique, or if it saves your bacon, please drop me a line. Thanks!)

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Bob LeVitus is a leading authority on Mac OS and the author of 39 books, including Mac OS X For Dummies and The Little iTunes Book.