Cairo Station Terminal
The terminal is on the left wall of the armory where Master Guns checks your armor. You can access it after the second Orbital Defense Platform is destroyed and you go through the lower hallway to reach the armory.
The terminal is in the last big open area where you fight the Phantom, Ghosts, and couple waves of drop pod reinforcements before you enter the tunnel to the bridge. It's in the lower level on the right wall of the building you first come across where the Marines have taken up position and have provided a Sniper Rifle and Rocket Launcher.
The terminal is in the building the Marines have taken refuge in before you face the Scarab. It's on the left back behind the crates in the first hallway after you destroy the three Wraiths outside and the Marines let you in.
The Arbiter Terminal
The terminal is in large room with the two blue «conveyor belts» moving fusion coils running across it after you clear out the hanger and go down a couple hallways. It can be found against the back wall of the raised platform in the right corner, really just up and to the right of the door you leave the room from and continue on.
The terminal is in the large two story room where you break the glass to drop down to fight waves of both Flood and Heretics after the long elevator ride. It can be found on the left side of the room behind a wall after you drop down.
Delta Halo Terminal
The terminal is in the large structure in the area where you need to extend the bridge to cross the chasm with two Wraiths on the other side. It can be found on the left wall of the room where you activate the bridge.
The terminal is in the large three story room after the first elevator ride where you face Elites, a pair of Hunters, and many Drones and Jackal Snipers. It can be found on the left side of the top level, right behind the giant hologram of Regret.
Sacred Icon Terminal
The terminal is in the first large platform that has a skybox, the one without the flood, after you fall down many fusion core tunnels and come to one with a divider across the end. It can be found behind the long support column on the right side.
Quarantine Zone Terminal
After entering the burning building, follow the hallways until you enter a room. Once in the room, stay on the ground floor and follow the wall underneath the exit, you'll find the terminal.
You'll exit to an outdoor area, and you should be able to spot this one in the distance to the left hand side across the entire area. On your way to exit this area, continue past the door to find the terminal.
You'll probably end up taking a ghost down a large flowing river/waterfall. You'll enter an area with a bridge and a wraith in the distance. If you go on top of the bridge that connects to the door, you'll find a terminal in one of the areas behind the pillars.
High Charity Terminal
After taking the elevator, killing the enemies, you'll enter a room with a sword. In this room, to the left of the entrance, you'll find the terminal.
The Great Journey Terminal
In the area with the prison cells, you'll find a terminal on the right hand side on the upper floor. You'll need to shoot down the shield in order access it.