GUID Partition Table formatting

[Anne]

A few weeks ago Tony (I think it was) posted the following url and related info:

partial quote:----------
http://www.macobserver.com/tip/2006/08/16.1.shtml

TMO Quick Tip - Format a Drive to Boot Intel Macs

by Jeff Gamet, 7:30 AM EDT, August 16th, 2006

Formatting an external drive to use as a boot volume for Intel-based Macs is easy to do, but if you miss one crucial step, your efforts will be wasted. Apple's new Macs require the GUID Partition Table (GPT) scheme for bootable disks instead of the older Apple Partition Map (APM). The problem is that Disk Utility formats external drives with APM by default.
endquote:----------

My question is, can you use a GPT formatted external HD with the older Macs, or only with the Intel-based Macs?

I've still got a G4 PowerBook, but will be buying a new (Intel-based of course) MacBook before the end of the year.  I've just bought a new Firewire external HD for backup, and am wondering if I can format it as GPT now, so that it is ready for the Intel-based Mac in future?

TIA!

Anne

[tonyinosaka]

HEY. What's with asking hard questions?

;-)

It seems, is no, or, at least not yet, or not so easily.

http://www.macosxhints.com/article.php?story=20071026051259471&query=power%2Bpc%2Bguid%2Bboot

"Intel Macs can "only" boot to a drive that is partitioned using the GUID partition table scheme, while PowerPC Macs can "only" boot to a drive that has an Apple Partition Map scheme."

However, read the comments. It seems more is possible, especially if one likes to play.

[Anne]

Thanks for the very comprehensive reply, Tony - sounds dicey, and think I'll wait until I have an Intel-based Mac, and then decide what to do!  I'll stick to the APM format for now.

Anne