Just got myself a Mac Mini to compensate for the fact that my Pegasos has been broken/at bPlan for ages now. Planning on dual booting with OSX, but I'd rather not have to burn any new discs to repartition (and would like to keep my existing data, of course). If I'm using Disk Utility on the 10.5 disc, does it matter whether I scale the Mac partition from the top or the bottom? In other words, does the top or the bottom of the block representing the partitions correspond to the right-hand side of the partition block in GPartEd?

Busy week and weekend ahead, but hopefully I'll have my MorphOS system restored relatively soon.

Thanks, all!

Big Smile in South Boston

You can move partitions as you like, but touching the bottom boundary will most likely mean that the process will take ages instead of minutes (since the data has to be copied).

I have just gotten Mac Mini myself and found myself in the same situation, that I did not wat to destroy the existing OSX installation.
I searched google and came across this excellent howto:
http://dreamolers.binaryriot.org/dualboot.pdf
look at section 4, as it describes your case.
The guide uses the Ubuntu 9.04 live cd for resizing the OSX partition, and preparing new partitions for MorphOS.
The only small trouble I had when following the guide was that booting from the Ubuntu cd, was that it failed to boot, until I found that I had to use the "live-nosplash" option for booting.
After this everything went like a dream.

Thanks for the pointers, guys. Turns out the Leopard Disk Utility can't even create partitions under 1GB (even with the decimal trick in the dual-boot guide) so I ended up having to use GParted from the Ubuntu Live CD. I'm up and running, but my PS2 to USB adapter happens to be a piece of junk so I can't do anything in OpenFirmware (like switching boot devices by holding Alt) unless I plug in a real USB keyboard. The adapter drops dead and power cycles in Poseidon/MorphOS with any keypress.

Almost there!

If you use gparted, beware of the checkmarck in the "move cylinders option", as i didn't notice it and it took long time to repartition.