really part 2 of this question, but its a different issue than what i thought. I've been doing some testing, the screen seems to be non flickery if more than 1/4 of the screen is black, if i have any other colour taking up more than 3/4 of the screen there's flickering along the horizontal axis (only).
I've ruled out it being flickering due to frequency (i had that before), so.. what could the issue be?
Its an old CRT (a compal F708) if it matters, OS is windows 7 (i haven't been able to test it in anything else yet), running at 1024x768 at 80 hz
EDIT: further testing shows its worse when there's lots of red or green in the screen. blue is not as bad. flickering stops totally when i reduce the size of the non-black area. I've not tried other combinations of colours.
By flickering, a horizontal line looks flat, and a vertical one looks wavey