1. Go to Halo Waypoint on the Xbox.
2. Press start at the main menu to enter Waypoint, then press the X button and you will see a Forerunner like code structure.
3. Watch the end of ALL Halo Anniversary terminals and you will see odd looking letters, write these down or watch them on YouTube and enter them.
4. Enter each code correctly and you shall unlock the original terminal video as well as 7,000 cR on Reach for your trouble, The Maw terminal is worth 32,000 though. Once you have typed in ALL codes you will see an 11th terminal called Threshold. Click and enjoy.