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Fairchild Channel F RGB notes


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#1 the_crayon_king OFFLINE  

the_crayon_king

    Chopper Commander

  • 192 posts

Posted Sun May 12, 2019 4:56 PM

So after driving myself crazy looking at what is going on it this circuit it appears

That only four pins of the 71445 set color. Its confusing because the methods they use are hard to follow.

On the data sheet it even has pins specified R, G, B someplace else. To put it short those pins do not matter for our uses; and will not give you RGB :(

 

Looking at how A and B go to pin 2  and 14 of the 74153 we can deduce that B is a lower value, A is higher, and A and B is highest.

Nothing (00) is black or blank idk; for my uses it doesn't matter.

 

This is because without A or B being a logic one you won't have either of the burst amplitudes applied, aka no color so either white or black.

 

 

That means to get color out you can only have 3 bit combinations on A/B 01, 10, and 11

 

 

 

-----------------------------------------------------------------------------------------------------------------

D C B A

D = A3; C =A2; B=A1; A=A0

0101 RED
0110 BLUE
0111 GREEN

0010 LIGHT BLUE
0011 LIGHT GREEN

1001 GRAY
1000 BLACK

0000 nc < ONE OF THESE MUST BE WHITE

0100 nc  < ONE OF THESE MUST BE WHITE

 

WHEN OTHERS PROBABLY AN ERROR OR BLANKING EITHER WAY NO COLOR

-----------------------------------------------------------------------------------------------------------------

Somebody should validate this if they can confirm/deny. I am not too sure about white atm.

 

I need binary or decimal values for the RGB color palette.

Uh I may have mixed up light blue/green and full blue/green


Edited by the_crayon_king, Sun May 12, 2019 5:25 PM.





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