[Coco] RGB2VGA color DAC improvements

[Luis Antoniosi (CoCoDemus)]

Hi all,

I have replaced the resistors for the vga output. Now the config is:

red and green: 750, 1500 and 3000 ohm
blue: 510, 1000 ohm

replace them for the proportional values: 510, 1000, 2000 and 390, 810 ohm

Here a video with the new colors. Also the board generates a color bar for
color calibration when is  has no video:

https://www.youtube.com/watch?v=H2XBNWHUe_k



Luis Felipe Antoniosi