Question for Homebrewers (Atari 2600 Colors)

[+Random Terrain]

Poll over. Please see these two posts:

 

atariage.com/forums/topic/240893-question-for-homebrewers-atari-2600-colors/?p=3287016

 

atariage.com/forums/topic/240893-question-for-homebrewers-atari-2600-colors/?p=3292295

 

 

 

I'm going to be editing the Interactive TIA Color Charts and Tools page very soon and that includes updating the colors in the charts.

 

Trebor kindly provided two choices for NTSC and two choices for PAL. No version is going to look exactly like your old TV. I'm going for close as possible, not perfect (since there is no perfect).

 

Which version do you think looks more like Atari 2600 colors on a classic TV? Saturated or less saturated? Please vote for your favorite under NTSC and PAL since I need both versions on the page.

 

NTSC Saturated

 

NTSC Less Saturated

 

 

PAL Saturated

 

PAL Less Saturated

 

 

 

Thanks.

[Rybags]

Gets an error when I just vote for one.

 

PAL saturated. Less saturated is just too washed out - the first 3 or 4 lumas look OK but the rest not.

I'm guessing he applied a formula that like the real deal oversaturates the low lumas but washes out the high ones.

[+Random Terrain]

Gets an error when I just vote for one.

 

PAL saturated. Less saturated is just too washed out - the first 3 or 4 lumas look OK but the rest not.

I'm guessing he applied a formula that like the real deal oversaturates the low lumas but washes out the high ones.

 

Yeah, it needs a vote for NTSC and PAL since I need both on the page. Thanks for voting. The winning NTSC and PAL versions will go on the page. I hope we'll get more votes by Monday or Tuesday.

 

Homebrewers, if you don't vote, don't come whining to me later that you don't like the colors. Now is the time for input.

[Andromeda Stardust]

I went with less saturated for NTSC. Too much can be garish. PAL is just bland either way.

[Mr SQL]

Those are great reference charts either way RT, but I think it may depend on the model.

[+Random Terrain]

I updated the first post with new images from Trebor. Should I kill this thread and start a new poll or leave it the way it is?

[JamesD]

On NTSC it depended on the color level and brightness settings.
I don't have the slightest idea on PAL since I've never seen that in person.

[+Trebor]

While items like Brightness, Contrast/Picture, Saturation/Color, Tint/Hue, etc., impacts what we see on the screen (and can be manipulated under Stella), the length of time a console is consistently running will provide a core/base palette.

In essence, there are four major phases that range from ~24.7 to ~27.7 degrees, regarding color shift:

COLD = First few seconds to upwards of a minute or two consistent run time.

COOL = Factory tuned setting.

WARM = "Ideal"...Matches tech docs descriptions and provides the full palette range of the console.

HOT = A system running for a while.

PAL (Saturated):

PAL (Desaturated):

Under PAL, some hues experience slight changes but overall nothing too drastic.

NTSC (Saturated):

NTSC (Desaturated):

For NTSC, Hues 2 through 13 experiences, similarly to PAL, only slight changes. Hues 14 and 15 experience drastic changes, Hue 1 is only affected by the display's hue/tint adjustment.

For simplification and best overall representation of the console, the WARM palette (~26.7 degrees color phase shift), both saturated and desaturated from NTSC and PAL, is being highlighted and utilized by Random Terrain at this time.

The complete package of palette files, including additional 0.5 degree increments for Stella, can be downloaded here.

[+Random Terrain]

For anyone who wants to know, I'm playing with some free JavaScript I found online that should let a visitor to the page choose from different sets of charts. That means we can stop voting since I should be able to have more than one version on the page.

It's possible that you could visit the page in the future and have these selections available:

Saturated: cold, cool, warm, hot
Desaturated: cold, cool, warm, hot

The only problem is that I'd have to do a lot of color picking and copying and pasting. 16 sets of colors x 128 = 2,048 instances of grab color, copy color code, paste color code, then copy those color codes again for to 3 to 4 more interactive sections and that's probably over 4,000 more instances of copy and paste. The good news is that the freeware program called PhotoFiltre displays the 6-digit Web color on the right side without needing to hunt for it (speeding up the process).





Update 01 (2015y_07m_30d)

Found a color picker called Instant Color Picker that lets me assign a hotkey for auto copy, so all I have to do is move the mouse pointer over a color and press my chosen hotkey to copy the hexadecimal Web color. Now I won't have to double click to highlight the color code and I won't have to press Ctrl + c to copy.



Update 02 (2015y_07m_30d)

I set up the z key to copy with Instant Color Picker and set up a macro using Alt + z that pastes and adds a space with Notepad++. I can keep my fingers over z and Alt and quickly copy and paste with less strain than using Ctrl + c and Ctrl + v.

[+RevEng]

One more wrench to throw into this fine kettle of fish... most (all?) six switch 2600's have a 680 ohm resistor between TIA pins 6 and 9, which boosts the chroma saturation. Later models omit it. So it's probably a good idea to plan for both high and low saturation.

[Thomas Jentzsch]

It's possible that you could visit the page in the future and have these selections available:

 

Saturated: cold, cool, warm, hot

Desaturated: cold, cool, warm, hot

Please make "hot" the default selection. Because that's how it will look like after a few minutes, which is what a developer should aim for.

[+Random Terrain]

Please make "hot" the default selection. Because that's how it will look like after a few minutes, which is what a developer should aim for.

 

Would it be a waste of time to include cold, cool and warm? It would be stupid to spend time doing all of that color picking, copying and pasting if nobody needs them.

[Thomas Jentzsch]

Would it be a waste of time to include cold, cool and warm? It would be stupid to spend time doing all of that color picking, copying and pasting if nobody needs them.

IMO hot is sufficient. With a note that the colors (especially green/the bottom of the matrix) may change a bit until the system is fully warmed up.

[+Trebor]

Some consoles have been noted to linger in the "Warm" (~26.7 degrees) for as little as ~5 and others as long as ~15 minutes of consistent run time. If a console is played in only quick 5-10 minutes one session game stints, the "Warm" may very well be the dominant palette experienced.

 

The "Cold" and "Cool" palettes are more for completion and FYI of what transpires regarding the console's base colors. Perhaps include just a link to pictures and a small explanation for the palette phases. No need for them all to be interactive though, just noteworthy, and with 'a picture worth a thousand words', it would better relay to developers what is meant by any changes to the console's palette.

[Thomas Jentzsch]

Some consoles have been noted to linger in the "Warm" (~26.7 degrees) for as little as ~5 and others as long as ~15 minutes of consistent run time. If a console is played in only quick 5-10 minutes one session game stints, the "Warm" may very well be the dominant palette experienced.

But as a developer, I cannot know in which interval my game is played or how long a console requires to warm up. So I have to assume something. Usually I would expect longer play sessions, even though the games may be changing.

[+Trebor]

But as a developer, I cannot know in which interval my game is played or how long a console requires to warm up. So I have to assume something. Usually I would expect longer play sessions, even though the games may be changing.

 

Completely understood and great points, Thomas. To be clear, stating "Warm" should be -the- absolute reference is not the case here; however, among the four main color phase shifts, "Warm" arguably offers the best compromise, leans very close* to matching "Hot", and is the reference point when comparing color descriptions in tech docs such as the Stella Programmer's Guide.

 

Still, there is a strong case made that "Hot" should be the primary reference point; nonetheless, the other phases should not be necessarily ignored or overlooked when developing games; especially in the case of the "Warm" palette.

 

*As a side note, between the "Warm" ~26.7 degrees and "Hot" ~27.7 degrees, ~27.2 degrees, would be another type of compromise, which is also offered in the Stella Palette file download, if interested.

[Thomas Jentzsch]

I can live with anything between warm and hot. I think the differences are very minor anyway.

 

But I think there are still more major issues (e.g. the one step to bright grays).

[+Trebor]

I can live with anything between warm and hot. I think the differences are very minor anyway.

 

But I think there are still more major issues (e.g. the one step to bright grays).

 

White balance/grayscale calibration will differ among televisions under either region. The palettes presume an ideal/even balance distributed across the phase shift ramp, but user serviceable settings such as brightness and contrast/picture, as well as non-user serviceable adjustments fixed for a particular display will affect results.

It's been noted seeing television displays where up to the first three levels of gray are considerably darker (and very similar to one another) than the rest, and others where even the first level ("black") is more brighter and gray-ish. Throwing in all the different desktop/tablet/laptop/etc. displays and their specification(s) creates further opposing experiences.

A fair compromise is what is being demonstrated. The ideal would be able to manipulate and adjust all display settings and variables as desired in 'real time'.

[Mr SQL]

One more wrench to throw into this fine kettle of fish... most (all?) six switch 2600's have a 680 ohm resistor between TIA pins 6 and 9, which boosts the chroma saturation. Later models omit it. So it's probably a good idea to plan for both high and low saturation.

 

This is what I was getting at; boosted chroma seems present on the Vader model too, whereas my Junior displays colors that look washed out by comparison. This might also vary for different board revisions of the same model.

 

And composite mod's seem to drop the chroma considerably, some more than others.

 

RT I'm not suggestion you make 100 charts but there's a lot of variability here.

[+Random Terrain]

Thanks for the replies. Before copying and pasting colors, I wanted to make sure this new code would work in multiple places. It didn't, so I copied the code, renamed the functions/variables and got a second version working. Now I know what to do so the page can have choices in multiple sections. Here's what the choices look like in one section:

 

 

The default selection will be saturated hot in all sections.

 

I'll see if I can do cold, cool, warm, and hot (saturated and desaturated under NTSC and PAL). I'll start with hot and work my way back down to cold. If my arm falls off before finishing, at least we'll have hot and warm.

[Thomas Jentzsch]

White balance/grayscale calibration will differ among televisions under either region. The palettes presume an ideal/even balance distributed across the phase shift ramp, but user serviceable settings such as brightness and contrast/picture, as well as non-user serviceable adjustments fixed for a particular display will affect results.

At least on my console, the grays are always darker than the colors. And I have talked to some other people from PAL land, who all told the same.

 

Maybe we should ask people for screen shots of a color palette?

 

It's been noted seeing television displays where up to the first three levels of gray are considerably darker (and very similar to one another) than the rest, and others where even the first level ("black") is more brighter and gray-ish.

On PAL or NTSC?

 

Throwing in all the different desktop/tablet/laptop/etc. displays and their specification(s) creates further opposing experiences.

I don't care for tablet etc. The emulator should create the colors how they looked like on a CRT.

 

A fair compromise is what is being demonstrated. The ideal would be able to manipulate and adjust all display settings and variables as desired in 'real time'.

Sure that would be best.

 

But for the PAL grays, I think I will be using my own palette (see attachment).

 

BTW: Do we know what is warming up? Would a modded Atari show the same color shifts? Or are they coming from the video section which is skipped by the mods?

Stella272a.zip

Edited July 28, 2015 by Thomas Jentzsch

[+Omegamatrix]

*As a side note, between the "Warm" ~26.7 degrees and "Hot" ~27.7 degrees, ~27.2 degrees, would be another type of compromise, which is also offered in the Stella Palette file download, if interested.

Just downloaded these and tried it out. Thank you very much.

 

I'm color blind. Are these saturated or de-saturated? I want to use the saturated one because most people voted for it.

 

I tried H.E.R.O.. On the default Stella palette I can see the dynamite real easy. On 27_7 it's hard for me to see. But this is good insight, and helps me plan my colors.

 

 

 

If other people try these palettes there are two things to do:

 

1) Under "Video Settings", change TIA palette to "user".

 

 

2) Under "Config Paths", direct the path to the new palette file.

[Thomas Jentzsch]

1) Under "Video Settings", change TIA palette to "user".

CTRL+P switches palettes (Stella, z26, user) too.

[+Random Terrain]

I think it might be done:

randomterrain.com/atari-2600-memories-tia-color-charts.html

If you visited the old page, you'll probably need to refresh the page for it to work properly. Please let me know if you find any mistakes.

[+Random Terrain]

Got some PM feedback, so the page has been updated again:

 

randomterrain.com/atari-2600-memories-tia-color-charts.html

 

I think it might really be done now.