The really interesting thing about the modern ATACs is that if you were to open them up, there is no logical scientific reason they should work at all. None of the gears connect, there are random pistons that do nothing obvious, spinny things full of phlogiston, that sort of thing.

Now, this is not so of the original ones, which fortunately utilize some form of advanced nanomachinery to keep themselves in repair. See, when they first dug the antique ones up, the chancery took them into custody for study and couldn't make heads nor tails of them. The chancellor, a real prick, would come down every day and ask what their progress on replicating them was, and every day he'd just should 'MAKE IT WORK!' when told they were still several squares from square one.

To get him off their backs they just slapped a bunch of random crap into the shell of their prototype and said it was working. They were worried when the chancellor demanded a demonstration until it inexplicably started working like any of it actually did anything. Without realizing it, they had stumbled on the greatest power in the world: the ability of stupid people to believe things that aren't so SO HARD that they become so. Thus the ATAC was born.