This is exactly how the World Wide Web works: the HTML files are the pithy description on the paper tape, and your Web browser is Ronald Reagan. The same is true of Graphical User Interfaces in general.

So an OS is a stack of metaphors and abstractions that stands between you and the telegrams, and embodying various tricks the programmer used to convert the information you're working with--be it images, e-mail messages, movies, or word processing documents--into the necklaces of bytes that are the only things computers know how to work with. When we used actual telegraph equipment (teletypes) or their higher-tech substitutes ("glass teletypes," or the MS-DOS command line) to work with our computers, we were very close to the bottom of that stack. When we use most modern operating systems, though, our interaction with the machine is heavily mediated. Everything we do is interpreted and translated time and again as it works its way down through all of the metaphors and abstractions.

The Macintosh OS was a revolution in both the good and bad senses of that word. Obviously it was true that command line interfaces were not for everyone, and that it would be a good thing to make computers more accessible to a less technical audience--if not for altruistic reasons, then because those sorts of people constituted an incomparably vaster market. It was clear the the Mac's engineers saw a whole new country stretching out before them; you could almost hear them muttering, "Wow! We don't have to be bound by files as linear streams of bytes anymore, vive la revolution, let's see how far we can take this!" No command line interface was available on the Macintosh; you talked to it with the mouse, or not at all. This was a statement of sorts, a credential of revolutionary purity. It seemed that the designers of the Mac intended to sweep Command Line Interfaces into the dustbin of history.