Installing Leopard on the G4 Cube

The PowerMac G4 Cube, arguably the coolest computer on planet Earth, is not supported by operating systems later than Mac OS X 10.4 Tiger, but there are many reasons you may want to run a later system. For me the main incentive to upgrade was that Apple dropped Tiger support with the release of iTunes 10, which means a Cube on 10.4 can not partake in the wonders of Home Sharing.

The minimum system requirements for installing Leopard on a PowerPC based Mac is an 867 MHz processor and 512 MB of RAM. The memory requirement isn't really a problem since the Cube supports up to 1.5 GB, and you wouldn't want to run Leopard on any less than 512 MB anyway. The processor speed requirement, however, is a problem since the fastest (unmodified) Cube runs at 500 MHz. Luckily there is a way to fool the Leopard installer's system requirements check by temporarily modifying the processor speed reported by the firmware.

Back up your Tiger

First off you'll want to create a bootable backup of your internal disk on a firewire drive. Do this using SuperDuper! or a similar tool, and make sure you can really boot from the backup drive.
No really, do not go on until you have succesfully booted from your backup and made sure it works.

Set the startup disk


Put your Leopard installation disk in your DVD slot, or copy it onto a firewire drive if your Cube can't read DVDs. Then set the installation disk as your Startup Disk in the System Preferences so that on next restart your Cube will boot from it and start the installation.

Modify Open Firmware


Restart your Cube, and hold Opt-Cmd-O-F during boot to enter the Open Firmware prompt. You will now temporarily set the reported CPU speed to 867 MHz and then continue booting. To accomplish this you will type some commands on the prompt, Open Firmware will respond with an 'ok' message after each understood command. The reported speed will revert back to the original value after next reboot.

For single CPU systems type the following three commands exactly as shown.

dev /cpus/PowerPC,G4@0
d# 867000000 encode-int " clock-frequency" property
mac-boot

For dual CPU systems use the following five lines.

dev /cpus/PowerPC,G4@0
d# 867000000 encode-int " clock-frequency" property
dev /cpus/PowerPC,G4@1
d# 867000000 encode-int " clock-frequency" property
mac-boot

Continue with the installation normally, and eventually end up with a Leopard Cube.



Thanks to MacRob on CubeOwner.com for turning me onto this solution.

Retro gaming on iPad, for iOS developers

MADTV and Gabriel Knight running in dospad on the iPad

Sometimes it's good to take a break from coding, and what's more relaxing than running some retro games on your iPad?

Getting DOS onto iPad

Some time ago a DOS emulator called iDOS briefly made it into the App Store, but it was already long gone when I heard of it and tried to download it. As luck would have it the source code for the app is available under the name dospad from Google Code, so any registered iOS developer can build it using Xcode and run it on their iPad.

I believe iDOS or dospad is also available for jailbroken iPads, for those who are not registered developers but are OK with jailbreaking their device.

Installing games

With dospad you get a fully functional DOS system for your iPad. There is mouse support and sound support, making it brilliant for some retro gaming. If the games are mouse driven you can even go full screen for a very immersive experience.

Sierra's adventure game Gabriel Knight is one of my all time favorites, and since I no longer have a floppy disk drive on my computer I downloaded it from an abandonware site called The House of Games, where there's a large selection of old DOS games.


With dospad installed on your iPad, you can drag files into it using iTunes. Just go to the iPad's Apps tab and select dospad under the File Sharing header.

Dospad comes with an unzip utility so once you have transferred the zip file with your game you can use the DOS command prompt to create a directory and unzip the file into it.


For Sierra games you then run install.exe to select your sound options. I selected Soundblaster Pro which seems to work well.

Launch the game by running sierra.exe.

Mouse controls

Obviously, this being DOS, you don't use it like a standard touch screen. Instead you control a mouse cursor on screen in the same manner you would using the touchpad on your Macbook. Tapping the screen left clicks at the position the cursor points to.


You can play either in portrait or landscape mode, as well as full screen.


Happy retro gaming, and make sure to save your game often.