Older firmware updates do not run in Mac OS X, they only run in Mac OS 9.

If the firmware you need to upgrade to is only available as a Mac OS 9 firmware upgrade, it is necessary to either install Mac OS 9 on the machine first, or to boot from an external drive running Mac OS 9.

Furthremore, what makes this extra complicated is that firmware upgrades must be run from a writable boot partition, which means you cannot run the firmware upgrade if you boot the computer in Mac OS 9 from a CD. It must be done from either the internal or an external hard drive (which is writable).

By Jason

One thought on “You must upgrade firmware before installing Mac OS X. However, what makes this extra complicated on older computers?”
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