Path: utzoo!attcan!utgpu!jarvis.csri.toronto.edu!rutgers!gatech!ncsuvx!mcnc!duke!romeo!currier From: currier@romeo.cs.duke.edu (Bob Currier - DCAC Network Comm. Specialist) Newsgroups: comp.sys.atari.st Subject: Screen flicker, top Keywords: flicker, top, screen, confused Message-ID: <15286@duke.cs.duke.edu> Date: 14 Aug 89 13:01:09 GMT Sender: news@duke.cs.duke.edu Lines: 25 Greetings, This weekend, while noodling around with animation, I came across a most puzzling phenomena. My graphics displayed fine while on the lower part of the screen (I am using a monochrome 1040), but when my little critters got about 30 or 40 pixels from the top they started to get a bad case of the flickers. I was using Vsync() to control flicker, and it seemed to work well, except for this twilight zone. I pulled my hair out for a couple of hours on this one, dug thru all my books, and finally, at about 1 a.m., in the premier issue of START, found a comment in an article about al graphics that went like this: "...vsync, but you will still see flicker near the top of the screen. This is a problem that can only be dealt with by very complex multiple screen flipping techniques..." So, does anyone know of this problem? What causes it? And, Virginia, how can I eliminate it? Bob Currier currier@romeo.cs.duke.edu rdc@northlab.ac.duke.edu