Strange booting error on MacMini

[knopy]

I have a perfectly OK running installation of Knoppix 7.2 in a USB 3.0 External Hard drive. When I use that drive in a PC it boots OK, but when I try to boot in in the mac mini, a black screen appears saying "boot error".My mac mini does not have OS X installed but Linux Mint.How can I solve this, so I can use my Knoppix in both machines?Thanks in advanceNacho

[knopy]

The same USD external drive, when connected to a PC boots perfectly. Also a simple ISO image boots normally on the mac, but once installed using the flash installer no longer boots. Black screen with the "Boot error" message.
Very weird.
Any clues?
thanks

[Werner P. Schulz]

Your problem doesn't seems so be a Knoppix problem.
Perhaps Mac computers FAQ (http://support.apple.com/kb/HT5172) will help you.