Need to install SL on Mavericks external drive I have a 2012 iMac 21" with the latest Mavericks.  I also have a need for a bootable Snow Leopard external drive so I can run Boot Camp with XP.  I purchased a Snow Leopard Retail install disk only to find the iMac refuses to boot from it and instead I get a blue screen with Black insert showing unix style error messages.  Sorry, but unable to capture these. 

I have no doubt I am missing something here, but at a loss for what it is.
Newer Macs can't run older OSX. 

A 2012 iMac will run a Mountain Lion and upward.