I discovered today (much to my surprise) that the PB 270c/ 280c can be read without backlighting - albeit only in a sunlit area. It is not altogether easy to read the screen in this way, but it is not impossibly difficult, either. I have read that this was also true of the greyscale PB170/ 180, but did not know that it was possible on an early colour active matrix screen.

I do not have a 170 or 180. Are the active matrix greyscale screens about the same or better than the colour screens as far as being legible without backlighting is concerned?