“A tiny square of light, known as the ‘cursor,’ began to move up the face of the tube. It was something like the bouncing ball that used to hop from word to word in song lyrics on movie screens. […] When the screen fills (it holds about a hundred and twenty-five words), the writer just keeps going. For every new line that comes on at the bottom, a line disappears at the top. To go back and look things over, just hit the SCRL key. The whole composition will roll backward or forward like a scroll.”