Terminals 4, 5, and 6 can all be found on the level, “The Covenant” on Halo 3. Each of the three shield generator towers has a terminal in it. Tower 1 and 3 both have the terminal near the elevator leading up to the shield controls. Tower 2 has the terminal just near the top of the ramp (on the opposite side of the Thunderstorm Skull Location).
Terminal 4
When you access the first Elevator leading to the tower controls, jump from the elevator platform to the platform on the opposite side from where you accessed the elevator from. The terminal is dead ahead.
Terminal 5
After getting a Hornet vehicle, fly towards tower 2 (the one that the Arbiter has already disabled). A voice will remind you that Tower 2 is already clear, just to confirm you are at the right place. The Terminal is just inside of the structure.
Terminal 6
Terminal 6 is identical to Terminal 4, only in the 3rd tower. Just jump to the platform, and there it is!
Back to Halo 3 Terminal Locations.