Pal color issue

[Heaven/TQA]

I am little bit confused with the palettes of emulators... me using a7800p for my PAL developments and when setting colors in my code I want to ensure that the colors match nearly the real hw ones.

 

Coming from a8 and not 2600 I am used to the Atari 256 palette.

 

Mitch tested some of my code on real pal machine mentioned that some colors are off like emu was showing.

 

That scares me off little bit esp when converting gfx from our artists. Even they use PAL palette in photoshop. And me picking those values and setting Maria they are different than I expect they should show up in emulator.

 

So whats the deal here? Even Schmutzpuppes gfx converter example of IK+ and Haunted C64 pic show different colors than screenshots.

 

Thanks for any help. Maybe I have set wrong emulator? But I am starting it with simple a7800p flag?

[Heaven/TQA]

ok. some miracle solved... I can display the palette in A7800 and take the values from there as the gfx converter by Schmutzpuppe seems to use the A8 palette which is wrong.

 

I hope that A7800 pal palette is correct or near the real thing.

[RevEng]

The a7800 palettes are as close to the real thing as you can get, when it comes to these things. (there are known consistency issues.)

 

Trebor, who has studied the issue for a long time, was the one that came up with the a7800 color palettes. They're derived from the YIQ (NTSC) and YUV (PAL) color models.

 

Trebor will come along soon, no doubt, and correct me or add some finer point about the colors.

[Trebor]

The Atari 7800 Color Documentation on 7800.8bitdev.org, overall, is really the most succinct source for a better understanding of the console's color palette.

 

RevEng specifically linked the consistency issue section which summarizes it best in understanding why the slight (and sometimes not so slight) variances among systems and displays.

 

Below in the spoiler highlights an Atari 7800 PAL console at factory setting of ~25.7 degrees and then the 1-2 degrees delta consoles experience as they 'warm up'; of course, items such as brightness and saturation will vary:

 

 

 

 

 

 

There's not a drastic difference for most values. Obviously, the Hue Fx range is one to be careful in utilizing. Also, note the transitioning of a stronger green for Bx and Cx, and more bluer tones for 7x and especially 8x, as the system warms.

[+Mitch]

It should also be noted that the PAL 7800 that I was testing on was a PAL RGB model. So the colors might be slightly different than a standard RF PAL 7800.

 

Mitch

[Heaven/TQA]

It should also be noted that the PAL 7800 that I was testing on was a PAL RGB model. So the colors might be slightly different than a standard RF PAL 7800.

 

Mitch

Mitch i had not slight color shifts but wrong colors in my latest bitmaps. I used the bitmap converter by Schmutzpuppe and hand matched the colors which was not like it showed in the tool.

 

But when I picked the palette values a7800 emu showed it matched correctly.

 

If you dont mind I would like to send you weekend a new built to test?

Edited March 14, 2019 by Heaven/TQA

[+Mitch]

Sure.

 

Mitch

[CatPix]

It should also be noted that the PAL 7800 that I was testing on was a PAL RGB model. So the colors might be slightly different than a standard RF PAL 7800.

 

Mitch

They so have color differences. I have one and I can access one in a retrogaming club. Mine display a brownish color where then other display a bright red!

[Heaven/TQA]

I tested my code on real 7800 myself and have to admit that mine matches nearly the palette of the a7800 glad I am so...

 

But the overall output is crappy never had such a bad console at all...

 

So will test this weekend on my parents Old CRT TV monster >100kg