I created a map with two brushes for television screens, two cameras, and one of the televisions works correctly.
The other television does not work correctly. It has the image of the first television scrolled slightly. After a while, I realized the camera was reading what it saw into one texture (dev/dev_tvmonitor1a), which was applied to both screens. The second screen, being slightly to the left and having its texture alignment set to 'World', was repeating the texture as it should. So, in order to have two screens displaying two different images, you need two different textures.
I tried creating a new texture and applying it to the face of the second screen. However, it didn't display what the camera saw, it only displayed the texture.
I assume there are special parameters applied to the .tga and the .vmt that tell Source, 'I'm a camera screen', but I can't unpack the game textures to see what they are. If someone does know--what they are, or how to unpack the game textures to look--let me in on the secret.
