I've got both Mountain Lion and Snow Leopard installed on my hard drive, but I can't boot from the hard drive no matter what I try!
To install Mountain Lion, I used the MyHack 3.3 Guide, which used to be located at myhack.sojugarden.com but is now available only from the WayBack machine at the following url: Archived MyHack 3.3 Guide. This worked perfectly, including being able to boot from the hard drive (although it only supported a MyHack, text-only boot screen).
But since the MyHack OSX Installer creation tool doesn't work for a Snow Leopard install, I used the "regae" boot CD and installer guide, located on this very site at: [GUIDE] Lion Retail & Snow Leopard 10.6.8 on ASUS P8P67 Deluxe B3. Although that assumed a different and older motherboard than mine (an ASUS P5WDG2 WS Pro), the Snow Leopard install worked fine, except that it would not boot from the hard drive. (By the way, I did not upgrade from 10.6.3 to 10.6.8 as the guide calls for because after trying to upgrade to 10.6.8 the system would not boot at all).
I was advised to install Chameleon on both the Snow Leopard and Mountain Lion partitions, so that I could once again boot from the hard drive, but no matter which version I install, I simply cannot boot from the hard drive. Instead, I always see the messages:
Now, please don't ask or tell me to forget about using Snow Leopard, because I absolutely need it because it is the last version that includes Rosetta (the PPC emulator), which I definitely need.
In the past, I've also tried to install Clover, but afterwards I could never get Clover to boot from the hard drive either.
By the way, my Hackintosh system requires a legacy BIOS and does not support UEFI.
Please help me solve this problem