How do you unlock all the black ops zombie maps?

i looked on the leaderboards and saw like 8 different levels. how do i unlock them.How do you unlock all the black ops zombie maps?
Five and dead ops arcade are got through breaking free by pressing l2r2 at the menu and entering 3arc unlock on the computer behind you
The other maps you see are maps you can only get through the harfened edition download code.How do you unlock all the black ops zombie maps?
there are only 3 maps...

Kino der toten

Five

and Dead Ops



To unlcok five and Dead ops, break out of the chair in main menu but alternatively hitting the triggers or your controller.



Then walk to the computer behind your chair and type in the following code



3arc_unlock



You now have all the maps.How do you unlock all the black ops zombie maps?
when ur at the main menu with the computer infront of you, keep pressing the shooting button (rt and lt) and then ull get out and walk to the computer on your left. type in 3arc unlock
Complete the campain will give u one and go on u tube and see the glitch if still there it's called "FIVE" with kennDy nocson and other people :) ok