Upgrade to 10.5 Operating system

My answer is from experience. I do this for a living, for over 25 years now. I don't just read about it. Your G5 processor machine can be upgraded to 10.5. You may then download the updates directly from Apple for free using the "Software Update" just under the Apple in the upper left hand corner of your screen to take it to 10.5.8. There is a difference between "Upgrade and update". The Upgrades are paid and the updates are free. I don't remember a time when Apple didn't provide for a cheaper upgrade from the previous system to the next, i.e. 10.2 to 10.3 or 10.4 to 10.5. You can purchase a Full Installation that requires no previous system on your hard drive. The Apple Store does not seem to be selling the 10.5 anymore (they aren't listed but Ralph say you can call to get it). But for example, you can go here: http://store.apple.com/us/search?find=OS... to see the price difference between a System upgrade at $26 or the full installation at $169.00. When doing a Upgrade from a previous system, it is advisable to do a "Archive and install" to retain proof that you have the previous system so the disk will work again should you have to do a reinstall. Although the Apple store isn't selling the 10.5 disks anymore they may be found on eBay. Go to eBay and do a search for "OSX 10.5 upgrade" I saw two listed tonight for $66.00. Do not buy the gray disks as they are only for specific machines. A upgrade disk may say "Upgrade" on it or "CPU Drop in", or may say nothing. Get the part number of the disk and do a web search to insure what it is. The "Full Install" disk scan be found as "OSX 10.5 Retail". You'll find a lot more of those at a higher price. A brand new Retail version can be had at FastMac http://store.fastmac.com/product_info.ph... for $179.95. Please note that once you upgrade to 10.5, the classic 9.2 system option will no longer be available. As for 10.6, you must have a "Intel processor" Mac to install it. I hope this clarifies your options.

If you have an Original iMac (1998-1999) you can run a maximum Of 10.3.9 panther. If you have an iMac G3 or G4 800Mhz or slower) you can only run tiger 10.4.11. If you have any iMac made after that, you can run leopard. If you have an intel iMac (2007 or later), you can run snow leopard.

I purchased a new copy of 10.5.6 from the Apple store online for $129 plus tax. Working fine in my new to me Powermac G5. I checked out Apple because of the outragous prices on ebay. Ralph

"Your iMac should take 10.5, but it's an upgrade you'll have to purchase. Strangely, it's pretty pricey. You'll need the full retail installation, which can be found in the eBay listings here.

EDIT:

Yep, you should be able to upgrade to Leopard just fine. It won't take the latest version, which is 10.6, but 10.5 should run normally.Provided you choose to ""Upgrade"" rather than erase and install, all your files should be fine.I think that all the apps you've mentioned above should work. The only kind of applications that 10.5 breaks are those that are written for OS9. Chances are, you were not using the Classic environment, so this shouldn't be a big deal.

As per where to get the discs, I'd try the solution that Ralph has given- that seems to be the cheapest way."