Lindy, On Sun, 23 May 2004 12:11:15 +0200, Lindy Mayfield wrote: >...< > Sorry, perhaps I wasn't specific about my "idea". (-: I meant I thought I could maybe do one where you have to look at it and shake your head NO! over and over to read it. No, because although you move your head, your eyes will fix on the spot you are looking at - it's really difficult to get your eyes to scan past something without stopping on the way, so all you'd see is a vertical row of lights varying in intensity. It's a physiology thing - our eyes don't work well when they're moving, so you actually move them in stops & starts, however hard you try to do it smoothly. Added to which you'd have to "scan" at the right rate, and syncronised with (say) the display of the start of the characters, and you'd have no way of doing that. It works exactly the same as a television scan (although with all the rows active at once, rather than sequentially downwards on a television). If the horizontal scan drive failed on a television so you had just a vertical line, there's no way you could see the picture by waving your head about! :-) Cheers, Howard Winter St.Albans, England -- http://www.piclist.com hint: The PICList is archived three different ways. See http://www.piclist.com/#archives for details.