this works on both consoles from the main menu try it
http://forums.xbox.com/34938574/ShowPost.aspx

probably some of the most fun ive had on this game

That's a class wee game very addictive

you can unlock the other zombie mode FIVE and DOA by putting 3ARC UNLOCK into the terminal - and also the intel unlock is 3ARC INTEL - i think if u do the intel cheat then it will cause you to be unable to get platinum for those who want it - i havent done this cos i want to do it properly and tbh not arsed about it atm