Xref: utzoo comp.sys.ibm.pc.hardware:9508 comp.sys.amiga.hardware:9971 Path: utzoo!utgpu!news-server.csri.toronto.edu!cs.utexas.edu!oakhill!val!ben From: ben@val.com (Ben Thornton) Newsgroups: comp.sys.ibm.pc.hardware,comp.sys.amiga.hardware Subject: Re: TURN COMPUTER OFF OR LEAVE ON? Message-ID: <1991Jun7.163234.3445@val.com> Date: 7 Jun 91 16:32:34 GMT References: <1991May24.033650.15836@cbnewsc.att.com> <20114@rsiatl.Dixie.Com> <1991May25.151636.679@monu0.cc.monas <1991Jun4.210249.1190@newserve.cc.binghamton.edu> <91156.110456GUTEST8@cc1.kuleuven.ac.be> <1991Jun6.003043.28563@gucis.sct.gu.edu.au> Organization: Video Associates Labs Lines: 31 anthony@gucis.sct.gu.edu.au (Anthony Thyssen) writes: >GUTEST8@cc1.kuleuven.ac.be (Ives Aerts) writes: >>On the point of screen blankers. We have here a little network >>of ps2/s running aix (ibm's version of unix) and they too have >>a screen blanker installed under x-windows. But.... the screen >>'blanker' displays a WHITE screen with a moving black X on it ||| >>What's the point ? Burning in the screen as hard as you can >>while the user isn't there ????? Someone who can explain this ? >>------------------------------------------------------------------------ >Only static (unchanging) displays burn in the screen as the same pixels >would always be on. A moving display uses different pixels and only a small >number normally, thus the image is not `burned' into the screen. No, the 'burn' is cause by bombardment of phosphors by electrons. This is what makes them illuminate, but it is also what causes them to burn. Over time, any crt's phosphors will burn in this fashion, unless the filament (yes, it's a fire bottle) dies first. Although motion in the video reduces the average number of electrons that strike any given phosphor point, it is the absolute number of bombardments that matter. Motion of the picture content, therefore, does not prevent phosphor burns, it merely postpones it. -- Ben Thornton packet: wd5hls@wd5hls.ampr.org Video Associates Internet: ben@val.com Austin, TX uucp: ...!cs.utexas.edu!val!ben What's the moral of the story?