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From: "Richard Cooper" <peajay@funrestraints.com>
To: linux-assembly@vger.kernel.org
Subject: video sync timing
Date: Sat, 27 Aug 2005 15:28:20 -0400	[thread overview]
Message-ID: <op.sv6lpibqnro9m0@sucks.airplane.fire> (raw)


Any ideas how I might sync to bit 3 of port 0x3DA, the video card's  
vertical sync signal?

Just watching the bit in a loop doesn't seem like a good idea, since the  
CPU could be off doing something else, but as far as I know any timer  
function I might use will only be accurate to 1/100 of a second, which  
wouldn't be much better than watching the bit in a loop.

Since things like DOOM run in Linux, I think there must be some way to do  
it.  I've discovered that simutaneously changing the screen data and the  
color palette without synchronization creates a flicker of a mess on the  
screen, and DOOM doesn't do that in Linux, so I guess it must be  
synchronizing somehow.

             reply	other threads:[~2005-08-27 19:28 UTC|newest]

Thread overview: 10+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2005-08-27 19:28 Richard Cooper [this message]
2005-08-29 21:25 ` video sync timing + softer update Richard Cooper
2005-08-30  1:40   ` Frank Kotler
2005-08-30 12:40     ` Richard Cooper
2005-08-30  2:54   ` Stephen Ray
2005-08-30 13:44     ` Richard Cooper
2005-08-30 17:36       ` Stephen Ray
2005-08-30 20:24         ` Richard Cooper
2005-08-31  0:51           ` video sync: result of 2.6 kernel experimenting Richard Cooper
2005-08-31  3:58             ` Stephen Ray

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