control electron guns in CRT directly without video signal generator?

[spacediver]

We were having a discussion over in the FW900 thread, and an issue came up regarding the advantage of having a video signal generator produce a pattern instead of using a video card.

For convergence adjustments, a video signal generator can turn on each gun individually to produce a "pure" beam to work with. In particular, a magenta cross hatch pattern (which is a combination of pure red and pure blue) is used.

My understanding is that if you tried to create a magenta color using a video card, the video card will try to render what it thinks is magenta, according to the ICC profiles etc. This will be a combination of inputs from all three guns more often than not, depending on how the system is calibrated.

Is there any software that exists that allows for more direct control over the electron guns? So, for example, if I want to have only the red gun produce a particular pattern, is there anyway I can do that through a regular video card?

(in case you're interested, the discussion starts around here: http://hardforum.com/showthread.php?t=952788&page=474 )

 

[Joseph F]

http://www.youtube.com/watch?v=gvdf5n-zI14

 

[spacediver]

I find that a bit confusing, since video signal generators communicate through the same port as a video card. Why can't you program the desired signal on the software side?