Halo 3 help.?

[KATTALNUVA]

How do you get to the secret skull and the 8th terminal on the Cortana level?

I also need help getting the catch skull, Even when I get up the big circular thing it isn't there (Even if the wraiths haven't been destroyed)
Also I found the seven other terminals but it never said I unlocked Marathon Man.
Non of those videos are helping.

 

[mustymex]

there is only 7 terminals the 8th one is just a easter egg you probably havent gotten the achievement because you have to wait in the terminals it will blink red and wait dont get out i had the same problem it will blink red then some more stuff will come up wait until it says //Fragment Ends// or till you keep tapping "A" untill nothing else happens that skull on the cortana level is above that terminal climb up find a way how to about the skull get the sniper in the middle area and zoom to see if it is there or before you start the campaign press "X" and see if you have it

 

[daz1190]

lol use youtube just type it in its all on there videos guides etc, or use this webpage which i used to get all the skulls http://www.halo3planet.com/halo-3-skull-locations/

 

[starcraft961]

How do u pronounce your name, Forget halo, get a life.