How do I read the Vsync register on my PC video card output?

I am desiging an application in LabVIEW that presents jpgs on the monitor. The problem is I need the presentation to be synchronized to the video refresh rate (I require mS timing in the application) and I inveriably get a jitter depending on when the CRT starts to "draw" the video signal. I need to be able to poll the video registers to "see" when the VSYNC pulse is initiated.

Hi Guyzini,
I remember seeing a similar post on discussion forum a few days back. Here's the link to it.
http://exchange.ni.com/servlet/ProcessRequest?RHIVEID=101&RPAGEID=135&HOID=50650000000800000034E80000&UCATEGORY_0=_49_%24_6_&UCATEGORY_S=0&USEARCHCONTEXT_QUESTION_0=%22How+to+synchronize+presentation+on+the+front+panel+to+the+start+of+a+75Hz+monitor%27s+retrace+cycle%3F%22&USEARCHCONTEXT_QUESTION_S=0
Please let me know if you have more questions on the issue.
Regards,
Ankita A.

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Modelview Matrix.jpg ‏71 KB
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