Halo 3.......Help with terminals

I am trying to find the 8 terminals in Halo 3. I have beaten the game once and I know where all the terminals are but does anybody know if you can jump to that point in the level and then exit without finishing it and if you do that for every terminal, then do you still get the achievements? I know that with the skulls you don't but I want to know about the terminals. Halo 3.......Help with terminals
From what I remember I think it is possible to progress on the next terminal as soon as you are done with the current terminal instead of completing the terminal and the mission.