2to1 VGA multiplexer to make DDC stereo adapter

[gisly]

Hi

I'm investigating the possebility of making a adapter with two VGA inputs whcih multiplexes these on one output with a DDC stereo control signal which then can be used with shutter-/head mounted displays.

My big question, before I do too much effort, is if anyone knows if the VSYNC (frame update) between two monitor outputs on the GPU are in sync when the refresh rate is set equal, or not?

[iondrive]

hi gisly,

I started a thread about that but it still needs work and there is much off-topic stuff there. Anyway, here it is:

http://www.mtbs3d.com/phpBB/viewtopic.php?f=26&t=4159" onclick="window.open(this.href);return false;

I will get back to that project eventually, but to answer your question. You need some luck and it depends on your card and possibly driver. I had great luck with my 7800GTX card and bad luck with my 8800GTS. With the 7800, I just needed to use either clone or dual output mode and set the same freqs and timing modes (fixed aspect ratio timing or any other as long as both displays were set the same). Check it with two CRTs and shutterglasses with a dongle on the primary using ED-Activator to turn them on. I think the 8800 will remain prohibitively difficult. I can get the same exact frequency, but the phase is always off and it's hard to get right. The 7800 just gets the phase easily. So it depends on your card. You just have to check it yourself. My system is speedier now so I have less need of this project, but I still want to do it eventually.

bye

--- iondrive ---

PS: feel free to merge your project into the other thread if you want.