Path: utzoo!utgpu!news-server.csri.toronto.edu!rpi!usc!sdd.hp.com!mips!daver!ditka!zorch!amiga0!mykes From: mykes@amiga0.SF-Bay.ORG (Mike Schwartz) Newsgroups: comp.sys.amiga.programmer Subject: Re: Mouse blanking Message-ID: Date: 10 May 91 09:40:25 GMT References: <9107@crash.cts.com> Organization: Amiga makes it possible Lines: 39 In article Frank.Neumann@arbi.informatik.uni-oldenburg.de (Frank Neumann) writes: >>Matt, what does DMouse do to prevent the sprite dma from being turned >>off while a sprite is being displayed? I'm still trying to find a good >>solution to that. >Although I'm not Matt ;^), I had a short look into dmouse-handler.c: > >> * note, sometimes the sprite gets turned on again, so >> * we re-off it every mouse-ptr-timeout >> */ >> if (doipcmsg(0x81) == 0) { >> WaitTOF(); >> OFF_SPRITE; >> custom.spr[0].dataa=0; /* sprite0 DMA */ >> custom.spr[0].datab=0; /* data register */ >> sproff = 1; >> } > >So - before switching off sprite DMA, he waits for the top of the frame - >in this time there is for sure NO sprite DMA, so it is a safe way - however, >one might think about what would happen if just after the WaitTOF() the >scheduler would do his work to give the CPU to another task...but this should >happen so rarely.. :} > By bumping your task priority to 127 before the WaitTOF(), you have a much better chance of another task not getting the CPU. By the way: custom.spr[0].dataa, etc. sure looks like going to the metal to me :) -- **************************************************** * I want games that look like Shadow of the Beast * * but play like Leisure Suit Larry. * ****************************************************