Color problems after composite mod.

[CrazyBoss]

Hi

 

I installed a composite mod a while back, its a 2609/NTSC

 

but after I played Shark Shark it seems like some colors are a bit off.

 

The Jellyfish is Magenta instead of Light Blue (or Cyan)

 

There are also something with the plants.

 

https://oshpark.com/shared_projects/Y9AoW16r

 

I used new components, but maybe a bad solder job?

 

Or should I try to change some values on the resistors or capacitors ?

 

[+grips03]

mod is here:

http://wiki.intellivision.us/index.php?title=Intellivision_Composite_Video_Modification

 

Do you have NTSC Intv?

[mr_me]

I think with shark shark, the background is cyan and the jelly fish are light blue. On some TVs light blue looks a little pinkish/purplish but clearly different from magenta which can look really pink. Ideally, it should look similar to original rf but nothing is ideal. I've heard of some mods where they had trouble seeing the jellyfish. What's wrong with the seaweed.

[CrazyBoss]

mod is here:

http://wiki.intellivision.us/index.php?title=Intellivision_Composite_Video_Modification

 

Do you have NTSC Intv?

 

Yes its an NTSC console.

[CrazyBoss]

I think with shark shark, the background is cyan and the jelly fish are light blue. On some TVs light blue looks a little pinkish/purplish but clearly different from magenta which can look really pink. Ideally, it should look similar to original rf but nothing is ideal. I've heard of some mods where they had trouble seeing the jellyfish. What's wrong with the seaweed.

 

The shark looks black, but with some blue ghosting, but I think there is a problem, cause a homebrew game i was working on, shows pink color, but emulator shows light blue.

 

I have been looking at rgb values for what I see, I cant see any pattern, most colors looks ok. I think I better try to find or code a color test mode, to compare.

 

I tried to fire Shark Shark up again, I guess the plants in the ocean should fade between two green colors, but those seems to fade between almost invisible and some kind of blue. Maybe my "green" value is to weak, which will make light blue more like magenta, and make the green plants more or less cyan.

 

But again, I dont see a any problems in Super Minefield, it looks good compared to Emulator colors.

 

I know the colors from the STIC can be a big subject, Joe have been talking about its not 100% clear how the colors should look, so maybe there are no Official documents shows the RGB values on each color.

For the Colecovision VDP we have those:

Colour           Y     R-Y   B-Y   R     G     B     R    G    B
0 Transparent
1 Black         0.00  0.47  0.47  0.00  0.00  0.00    0    0    0
2 Medium green  0.53  0.07  0.20  0.13	0.79  0.26   33  200   66
3 Light green   0.67  0.17  0.27  0.37  0.86  0.47   94  220  120
4 Dark blue     0.40  0.40  1.00  0.33  0.33  0.93   84   85  237
5 Light blue    0.53  0.43  0.93  0.49  0.46  0.99  125  118  252
6 Dark red      0.47  0.83  0.30  0.83	0.32  0.30  212   82   77
7 Cyan          0.73  0.00  0.70  0.26	0.92  0.96   66  235  245
8 Medium red    0.53  0.93  0.27  0.99	0.33  0.33  252   85   84
9 Light red     0.67  0.93  0.27  1.13! 0.47  0.47  255  121  120
A Dark yellow   0.73  0.57  0.07  0.83	0.76  0.33  212  193   84
B Light yellow  0.80  0.57  0.17  0.90	0.81  0.50  230  206  128
C Dark green    0.47  0.13  0.23  0.13	0.69  0.23   33  176   59
D Magenta       0.53  0.73  0.67  0.79	0.36  0.73  201   91  186
E Gray          0.80  0.47  0.47  0.80	0.80  0.80  204  204  204
F White         1.00  0.47  0.47  1.00  1.00  1.00  255 255 255

Edited May 14, 2019 by CrazyBoss

[mr_me]

On my TV the sky in B17 Bomber which is the 14th colour light blue, looks pink; magenta (13th colour) looks very close to red. You can't compare to emulator colours; Joe changed jzintv colours last year. Pal intellivision colours might have been closer to original design. As you know ntsc intellivision colours don't match pal. Are you using a crt or lcd television? Do you still have the intellivision RF modulator to compare?

[+grips03]

Never the Same Color

MTE cart/rom has a color chart. I've never seen the same colors on my various Intellivision's with with RF, composite or RGB. Perhaps someone will make a fully adjustable mod board that does that. The Intv wiki composite mod is from Joe and Jeff. But I'm sure they are sick of answering questions on it. I posted the PCB drawing to make it easier for DIY type folks to do the mod themselves.

[ChildOfCv]

So it uses a 2-stage common emitter amplifier. I wonder if the simple Atari composite mod board would work as well if not better?

[CrazyBoss]

I did a small color test rom, and it seems like I can actually adjust the colors to match better, I cant compare to the RF, cause I have no TVs that can adjust to the NTSC output. But anyway, it can be ajusted, the problem is I use the same tv for ColecoVision, Memotech MTX, C64 and Vic20, and if it looks good at the Intellivision, it will look bad at the other platforms, but maybe I just need to adjust when needed.

[mr_me]

What exactly are you matching the colours to? Adjust the colours for normal television viewing and then post some photos of intellivision screens so we can see what you are talking about.

Edited May 15, 2019 by mr_me

[+grips03]

If you do take photos, make sure they match what is on the screen. I did this with Joe and Bruce a few years back and the photos didn't match the colors I saw on the TV. Had to take several photos in order to get a match. emerson is working on a new RGB board. Bruce Abbott made a RGB board. Maybe RGB is an option on your TV?