10.4.8 external HD wont boot in 10.5.6

[TSRP]

Hello there, I am not sure If any one can shed any light on this, I have an Intel MacBook running 10.4.8 there are music plug ins that I use in logic 7.2. I have not used it for many many months now, how ever now I have some time I would like to get some stuff done. When I bought my new iMac which is running 10.5.6 I was told I would be able to make a bootable copy of my MacBook plug it in through firewire/usb and use it on my new iMac. But when I try to start up from my bootable copy my MacBook just restarts like a loop all the time! can anyone shed any light? I would not have worried about it before but the plug ins I have will not work on anything newer than 10.4.11 (even running Under rosetta)
thanks....

 

[Cave Man]

Did you initialize the external drive with a GUID partition table? If not, it won't boot an Intel Mac. When you turn on the computer, do you hold the Option key to get bootable volumes?

 

[PeggyD]

Apple says Don't install a version of Mac OS X earlier than that which came with your Mac. That would include trying to boot from an earlier version installed on an external drive.

 

[Dave Braine]

Did you initialize the external drive with a GUID partition table? If not, it won't boot an Intel Mac

Not so. A PPC Mac won't boot from a GUID partitioned ext HD but Intel Macs will boot from an APM partitioned HD. I have one PPC and two Intel Macs, so my external drive is partitioned using APM and both Intels boot fine.