I noticed in the quest when your figthing for the dam with the NCR, about half way through when you enter the checkpoint ontop of the dam (The "shack" on the road in the middle of the dam), theres a computer terminal that is "Very Hard" to hack. I was just wondering if its anything special, i believe the ONLY time you can hack it is during this quest and i don't have the skill to do it.

Yes, it is a very Special Terminal.