I'm trying to recreate the colours generated by NTSC Ataris, in order to improve the Atari800 emulator's video output quality; and I want to make it as accurate as possible. I am well aware of previous threads in this topic; I've even contributed to some of them. I'm also aware of a routine posted in this thread, that aims to recreate the NTSC colours. However that routine was based on only one NTSC screenshot, and that's not enough to consider it accurate. Additionally, the aforementioned screenshot contains a certain irregularity in its colours, and I'm not able to develop a mathematical basis for it.
So I'd like to ask those of you who own NTSC Ataris and have access to a video capture device, to make some screenshots for me I've attached a program (in BASIC and as a DOS file) that generates a 256-colour screen. Please make a screen-grab of that program running and post it here.
Now I've heard that modern PC video capture cards may not synchronise properly to Atari video output, and may produce unstable display. As long as some colour info is retained, such display would still be useful for me, so please post it anyway. Also provide some additional information if possible: computer model, whether it's GTIA or CTIA (yeah right), was it modified to S-VIDEO output, ClearPic or whatever.
Based on gathered screenshots, it might then be possible to develop an accurate colour generation.