I always thought they were defunct http://www.dansmc.com/microfiche_reader.jpg machines. Are you talking about those things that lay around in the broken down museums, libraries, and schools?
Yeah I have seen a lot of them in the Arlington Library, which made me think that maybe they were for reading old newspaper articles. But now I think maybe they're supposed to be like those big microscopes that are sort of shaped like computer monitors and allow you to see bacteria on the screen. The way the screen looks is kind of similar because it's not really like a glass TV or computer screen, it has a bit of a fuzzy look (I don't really know how else to explain it...), and it has knobs for turnig which I'm guessing is to improve the quality of the screen.
I think that's the most plausible possability. :shrug:
Edit: No I don't think it's a supercomputer, that would be those tall metal machines with all the flashing buttons and lights.