Commodore VIC and VIC-II VDPs

[ColecoFan1981]

Hi,

 

This question goes out to all those who are familiar with the Commodore VIC-I and VIC-II video interface chips: does anyone know what the R-Y and B-Y differences are for each of the 16 colors (NTSC) these two VICs represent?

 

The VIC-I palette:

0 - Black (luminance: 0.0)

1 - White (luminance: 1.0)

2 - Red (luminance: 0.25)

3 - Cyan (luminance: 0.75)

4 - Magenta (luminance: 0.5)

5 - Green (luminance: 0.5)

6 - Blue (luminance: 0.25)

7 - Yellow (luminance: 0.75)

8 - Orange (luminance: 0.5)

9 - Light Orange (luminance: 0.75)

A - Light Red (luminance: 0.5)

B - Light Cyan (luminance: 1.0)

C - Light Magenta (luminance: 0.75)

D - Light Green (luminance: 0.75)

E - Light Blue (luminance: 0.5)

F - Light Yellow (luminance: 1.0)

 

The VIC-II palette:

0 - Black (luminance: 0.0)

1 - White (luminance: 1.0)

2 - Red (luminance: 0.3125)

3 - Cyan (luminance: 0.625)

4 - Magenta (luminance: 0.375)

5 - Green (luminance: 0.5)

6 - Blue (luminance: 0.46875)

7 - Yellow (luminance: 0.75)

8 - Orange (luminance: 0.375)

9 - Brown (luminance: 0.25)

A - Light Red (luminance: 0.5)

B - Dark Gray (luminance: 0.3125)

C - Gray (luminance: 0.46875)

D - Light Green (luminance: 0.75)

E - Light Blue (luminance: 0.796875)

F - Light Gray (luminance: 0.625)

 

While I know that Philip Timmerman's page (http://www.pepto.de/projects/colorvic/) provides the bulk of useful information about the colors of the VIC-II chip, what I would like to know is how to get the NTSC-equivalent colors of the C-64, in terms of the R-Y and B-Y color difference values. The same arguments also apply to the VIC-I chip. The VIC-II chip substitutes three shades of gray for the VIC-I's Light Cyan, Light Magenta and Light Yellow.

 

Thank you,

 

 

 

Ben Edge (ColecoFan1981)

[Garak]

Hi,

 

This question goes out to all those who are familiar with the Commodore VIC-I and VIC-II video interface chips:

 

The people most familiar with the VIC-II either don't come here or rarely do. But they can be found at CSDb and at Lemon64. Likewise for the VIC-I Denial would be more appropriate.

 

Thank you,

 

No problem.

 

Garak

[ColecoFan1981]

The I and Q values I got, from the calculations that Philip "Pepto" Timmerman had devised, are:

 

0 - Black (Y' = 0.0, I = 0.0, Q = 0.0)

1 - White (Y' = 1.0, I = 2.98, Q = 2.98)

2 - Red (Y' = 0.3125, I = 0.13, Q = 0.02)

3 - Cyan (Y' = 0.625, I = -0.12, Q = 0.02)

4 - Magenta (Y' = 0.375, I = 0.02, Q = 0.12)

5 - Green (Y' = 0.5, I = -0.02, Q = -0.12)

6 - Blue (Y' = 0.25, I = -0.07, Q = 0.11)

7 - Yellow (Y' = 0.75, I = 0.07, Q = -0.11)

8 - Orange (Y' = 0.375, I = 0.12, Q = -0.02)

9 - Brown (Y' = 0.25, I = 0.11, Q = -0.07)

A - Light Red (Y' = 0.5, I = 0.13, Q = 0.02)

B - Dark Gray (Y' = 0.3125, I = 7.45, Q = -7.45)

C - Gray (Y' = 0.46875, I = 2.98, Q = 0.0)

D - Light Green (Y' = 0.75, I = -0.02, Q = -0.13)

E - Light Blue (Y' = 0.46875, I = -0.07, Q = 0.11)

F - Light Gray (Y' = 0.625, I = 1.49, Q = 0.0)

 

Sources: Color Space Conversions

 

~Ben

Edited September 3, 2009 by ColecoFan1981