You can use an Ethernet cable to connect two Mac computers to share files or play network games. You don’t need to use an Ethernet crossover cable. On each Mac, choose Apple menu > System Preferences, click Sharing, then note the computer name for each computer.

My iMac G5 runs Leopard, so it can’t run classic games and other Mac OS 9 applications. In conclusion, a low-end PowerPC Mac from the early-2000s or late-90s is still a very usable machine that allows you to be productive and have fun at the same time.

iMac G5

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.

The Apple iMac G5/2.1 20-Inch (iSight) comes equipped with a 2.1 GHz PowerPC 970fx (G5) processor with an optimized AltiVec “Velocity Engine” vector processing unit and a 512k on chip level 2 cache, 700 MHz frontside bus, 512 MB of 533 MHz PC2-4200 DDR2 SDRAM, a 250.0 GB (7200 RPM) Serial ATA hard drive, a vertically- …

Mac OS X Leopard

You can’t upgrade for free. You can upgrade to Mountain Lion from Lion or directly from Snow Leopard. Mountain Lion can be downloaded from the Mac App Store for $19.99. To access the App Store you must have Snow Leopard 10.6.

Official solution (or what I undestood reading Apple website)

1. buy the DVD of Snow Leopard (10.6) from online Apple Store and install it on 10.5.
2. update the OS until 10.6.
3. use the App Store to download and install El Capitan.

Releases

Apple has sent out an email to MobileMe customers offering a free upgrade to as part of its “Get your Mac ready for iCloud” program. To get your free upgrade click here, log in to your MobileMe account and fill out your mailing address. You will be sent Mac OS X 10.6 “Snow Leopard” on DVD for you to install.

Snow Leopard is the first only-on-disc upgrade to Mac OS X since the MacBook Air debuted. Remote Disc isn’t limited to the MacBook Air, however; you can use the feature to install Snow Leopard on any Snow Leopard-compatible Mac currently running Mac OS X 10.4. 10 or later.

You can purchase Snow Leopard through the Apple Store: Mac OS X 10.6 Snow Leopard – Apple Store (U.S.). The price is $19.99 plus tax. You will be sent physical media by mail after placing your order. After you install Snow Leopard you will have to download and install the.

Install Snow Leopard while keeping files, applications, and settings

1. Insert the install disc (or the first install disc if you have more than one) into your disc drive.
2. The Mac OS X installer should open automatically.
3. When the Mac OS X installation finishes with the disc, restart your computer.

Copy the installation media

1. Open Disk Utility, and drag the Snow Leopard . dmg installer into the pane on the left.
2. Select the Snow Leopard .dmg you just dragged in from the list on the left, then the ‘Restore’ tab.
3. Drag the Snow Leopard .
4. Make sure “Erase Destination” is checked.
5. Click ‘Restore’.

Most Mac software is now available for immediate download through the Mac App Store (requires OS X 10.6 or later). Online, Apple offers some software products for purchase, boxed and downloadable, including previous versions of OS X.