gillies@m.cs.uiuc.edu (10/11/89)
Old-style VDT's show burn-in very easily. This is because the phosphor between lines is seldom lit (except by the descenders in "g", "j", "p", "q", and "y"). Thus, an old-style VDT has a 24*80 little tiny boxes, where the characters are written, and a light-colored grid between the lines and characters. A Macintosh, with its white-on-black desktop, probably burns in more evenly (and more quickly). If you entire Mac burns in evenly, it would be hard to perceive. To perceive burn-in, erase the entire screen. I bet your menu bar is already burned it, but you can't tell (except during boot time, when that region is erased). The net effect is that the screen will become progressively dimmer in certain places, as time goes on.