What's the latest Mac OS I can use with my older G4 Mac?

Question

Hi Everyone,
My oldest Mac, a G4 running at 350 gHz, still has OS 9.2 and I'd like to upgrade the OS to the best version the Mac can handle. I tried calling the Apple CAre hotline and a kind AppleCare specialist asked for my old Mac's serial number, and said I could install OS 10.4.
Well, a good friend of mine happened to have Mac OS 10.4.7, but it won't install. It starts, but goes into basic and states it's hanging.
Apparently, 10.4 is too advanced or, did I do something wrong?
Where on the Apple website can I find which OS would work best on my older Mac?
Thanks.

Answer 1

If that computer has never had an OS X newer than OS X 10.1 installed in it,
you probably should check the Firmware (boot ROM) version noted in the
OS 9.2 running system's "System Profiler" to see what the firmware version is.
And then see if the computer needs to have the Firmware Update applied
before attempting to install an OS X version into the computer. It will need to
have a running OS 9.1/9.2 kind of system booting the computer in order to be
able to install a Firmware Update.
Lack of the proper firmware update can compromise the computer's hardware.
• Available Firmware Updates - Mac OS X:
http://support.apple.com/kb/ht1395
The installation instructions are should be carefully read & understood.
Also, in older iMacs and other early PPC Macs, you have to be sure the
computer's hard disk drive size capacity is correct, if upgraded to a larger
capacity hard drive; some old models need to have a small (8GB) partition
for the OS installation. Later ones don't require this, but may have a limit
on the total capacity of a drive used in certain older computers.
For general specifications on several different Apple hardware (and OS)
products, you could download a fairly good database of information from:
• MacTracker:
http://mactracker.ca
To see about purchasing an OS X 10.4 full install disc (aka retail) you could
check the auction sites or local Mac user groups, craigslist ads, and other
local dives or recycling centers; or try calling the main Apple sales support
number as shown in the Apple web site, 1-800-MY-APPLE and ask to speak
to a product specialist for Mac OS X 10.5 Leopard, if the person you talk to
does not appear to know about the older no longer listed Leopard install discs.
Be prepared to purchase when you call; the phone number is not a retail store.
(You may have to pay significantly more than their asking price for questionable
goods through some auction; and some web resellers of discs sometimes sell
the incorrect discs, in an auction sale, for more than the cost direct from Apple.)
Hopefully you aren't planning on a modern experience in that old a Mac.
Good luck & happy computing!