How does the operating system know the Monitor's or the TV's resolution

[knowledge2121]

I use windows 7, when i right-click on the desktop and choose screen resolution, a window appears which tells me my current resolution + all available resolutions. I want to know how the OS knows the maximum resolution of the monitor, projector or HDTV that is connected to the graphics card....anyone ?

 

[COLGeek]

Via these mechanisms:

http://en.wikipedia.org/wiki/Display_Data_Channel

http://en.wikipedia.org/wiki/Extended_display_identification_data

 

[k1114]

Any display will send displayID or EDID with all the info.

 

[jaguarskx]

It's called "voodoo".

 

[knowledge2121]

thank you all