In Halo 4 Requiem mission, we can find the first Halo 4 Terminal hidden in the game. Halo 4 Requiem is actually the second mission in Halo 4, and it begins after the events of the prologue, named Dawn.
At the end of Dawn, Master Chief and Cortana crash with the spacecraft named Forward Unto Dawn into an unknown Forerunner planet.
Halo 4 Requiem starts when Master Chief wakes up surrounded by the debris resulted from the vessels caught in the gravity well; and as soon as he ends his conversation with Cortana about her deteriorating condition as an AI, we can proceed with our objectives.
Since, the Halo 4 Requiem Terminal is to be found at the end of this chapter, we dont need to worry about it for the first two parts of the mission.
Having survived the destruction of the Dawn, Master Chief and Cortana search for a way off the mysterious Forerunner planet.
RALLY POINT ALPHA
With Cortanas rampancy threatening her survival, Master Chief looks for a ship which can get them home in time to save her.
RALLY POINT BRAVO
As they search for passage off the Forerunner planet, Chief and Cortana intercept a transmission of unknown origin.
Halo 4 Requiem Terminal Location
The first Halo 4 Terminal can be found in the second mission named Requiem, while playing the third part, where we have to climb to the top of the large tower (right before the end of the mission).
As soon as we enter the large hall, some sort of giant pillars shift to the left and right sides of the room. In front of us is a ramp that leads to an elevator (our objective). Instead of going up on the ramp, we check the area below it, where we can find a strange looking device with a sphere in the middle.
This is the first terminal, and if we press X on the controller, we collect it, and we also unlock an achievement.
We end Halo 4 Requiem soon after we find the collectible, and we can start the next chapter in the video game, named Forerunner.