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Trebor

NTSC Color Palette - CRT TV Default & Tuning Varieties

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Already having discussed the problem we have (http://www.atariage....2/#entry2659435) when trying to use the raw video output, straight RGB values coming from a NTSC A7800, in a palette for emulators which lack proper NTSC video emulation (especially YUV/YIQ support), what will be accomplished here is taking YUV/YIQ achieved colors turn them 'vibrant' and make hard RGB values from them.

 

In that same thread here... http://www.atariage....2/#entry2659624... you'll notice that true NTSC/YIQ/YUV simulation created multiple shade for each color value. So we will take some of the greater values and make a VIBRANT palette from it.

 

The palette will be bright and brilliant respecting red against green, and blue will be stronger relative to the RAW palette or even a default derived YUV palette.

 

Again this is to simulate the colors many NTSC users likely saw from their analog CRT TV's favoring more vibrance. This end result being limited with just an RGB palette and no further video controls working off the RAW palette from the previously linked thread.

 

MESS is closer to ideal: http://www.atariage....2/#entry2660238 but I know many like using ProSystem and wanted to provide this for the community.

 

Here is the NTSC_A7800_YUV_VIBRANT palette and color chart:

NTSC_A7800_YUV_VIBRANT.zip

 

post-18-0-19150900-1356729114_thumb.png

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*THE* YUV/YIQ Default Palette is here: NTSC_A7800_YUV_DEFAULT.zip

 

We have the RAW video coming from the 7800 in palette form, and we have just a capture of that RAW video palette converted to YUV (The palette intended to be seen on a traditional CRT). The previous post started with taking technically accurate default YIQ/YUV values and enhanced them through a focused proportional influence of the value of red against the entire palette. So, if you prefer the VIBRANT palette above, that is great.

 

For the sake of accuracy, this is *the* CRT-TV YIQ/YUV default palette. You take the RAW video values --> convert to YIQ --> then form a near exact match (within reason) of the colors converted to RGB values.

 

Notice the Color Demo ROM capturing the following below...

RAW (NTSC_A7800_RAW.pal) --> YIQ/YUV enabled video --> Closest possible RGB of YUV (NTSC_A7800_YUV_DEFAULT.pal):

 

post-18-0-31739300-1356903450_thumb.png-->post-18-0-08979500-1356903455_thumb.png-->post-18-0-11261900-1356903456_thumb.png

 

 

As explained in prior posts, we know the exact configuration of values coming straight from the back of an NTSC A7800. We also have an exact color correction frequency (3.59754545) applied to those raw values. All that was left is to build the palette from it without any bias. It is done - A near exact (as close as possible) match.

 

Another palette I will post after this one is a OverDrive palette. The red and blues will appear to be strengthened and overall it will fall between the VIBRANT and this DEFAULT regarding RGB values, but the OverDrive palette may appear 'richer' than the VIBRANT palette due to contrast, brightness, saturation, and gamma tweaks applied.

 

'NTSC_A7800_YUV_DEFAULT' is the non-bias, as close as possible palette utilizing RGB only in providing colors that you were intended to see on a 'standard' NTSC CRT TV with settings in the "neutral" position.

 

Thanks for reading and I hope this has been both helpful and enjoyable.

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Those look fantastic! I really admire your work here Trebor.

 

I'm partial to the Vibrant one, but I wonder if those are really how the 7800 coders back in the day intended for these to look, or if that's just how it ended up when the hardware department designed the compromised Luma and Chroma signal crossover for the 2600 and 7800 lines. I also really like the "red push" variants in your previous NTSC Final palettes thread. Particularly the EX R07-09. They seem to give the best representation of "good" color for what these games were intended to look like if you compare the 7800 ports to the Arcade version, or other contemporary console Ports (NES, C-64, SMS, etc)

 

Specifically you can see what I'm talking about with Commando and Donkey Kong. If you use a palette with a moderate red push (NTSC_R08EX.pal for example) and then compare those to a screen shot of the Arcade versions of those games, and NES ports, the red push seems to be dead on to what the other version looked like.

 

But yes, the YUV default and Vibrant palette files you've posted here are about as color-accurate as you're going to get with what a genuine 7800 really puts out. Especially a Compositie or S-Video modded 7800, which tend to skew even more to the green scope of things than original RF output.

 

I've long wanted to add a tint control element to the Composite mod circuit in my 7800 so I don't have to tweak the Tint control on my CRT TV to get the 7800 games to look how I like, since I have other systems hooked up to it which are then negatively affected by the 7800 tint tweak. Unfortunately, I lack the electronics hardware knowledge to create a tint altering circuit for composite video, and there's even less useful information on the internet about trying to make one.

Edited by 7800 Emucoder
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Thanks for the compliments and info. Your second post here - so welcome to the boards (Although, you may have been around much longer than post count indicates). In any event, thanks again and hope to be seeing more posts from you.

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Thanks. Yeah, been in and around for a while, just getter back into thing, emu-wise after a while away from it.

 

I always wondered what the coders of Commando and worse, Tank Command were thinking with those color choices. Did they have really bad test monitors, or we're their Dev systems working in a different palette? Same could be said for Ms. Pac-Man.

 

Maybe they were just really, really high. Lol.

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I always wondered what the coders of Commando and worse, Tank Command were thinking with those color choices. Did they have really bad test monitors, or we're their Dev systems working in a different palette? Same could be said for Ms. Pac-Man.

 

When I first started working on the 7800 palette creation I thought for sure there was some weird or obviously butchered settings involved due to that fact of some colors being poorly chosen for some games. Or I figured the system jusrt wasn't capable of the colors required.

 

I was dead wrong in my thinking... Seeing Pac-Man Collection and Donkey Kong XM just does to show how near arcade exact they could have originally been chosen. Commando is pretty bad, but Ikari Warriors is worse...yuck!

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Trebor, thanks for doing this. It is absolutely invaluable!

You are welcome.

 

I'm absolutely hoping for it to be made obsolete sooner than later. I much rather see NTSC generation from start to finish simulated in all 7800 emulators. MESS comes the closest, just requiring the RAW values (NTSC_A7800_RAW.pal). It then can convert to YUV/YIQ and nearly all NTSC effects and artifacting is present. That is why Tower Toppler looks so good. Hoping to see strides with ProSystem or perhaps even a new 7800 emulator to emerge.

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Hey 7800 Emucoder,

 

'NTSC_R08EX.pal' is a part of the batch of palettes that had the Phase Shift set to 26, instead of the correct 25.7. While the reddish push is possible along with the modifications to saturation and contrast, the overall palette is impossible by 0.3 of a degree. The hue start point can vary greatly (Which sets the overall greenish/reddish tint), but the phase shift does not. Honestly though, from the human eye perspective you may not notice much of, if any, difference.

 

However, for the sake of my (*ahem*) borderline OCD, I wanted to provide the palette you mentioned (NTSC_R08EX.pal) with its contrast and saturation push along with the respective hue begin/start point. The only change is the correct phase shift value of 25.7.

 

If interested, here it is with the added '_CPS' to the name for "Correct Phase Shift": NTSC_R08EX_CPS.zip

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Perfect. That exactly matches the colors on my CRT with the tint adjusted a few notches toward red. Now if I could fingure out how to adjust the composiite video in my 7800 to do this for me, I could stop being so OCD about this as well.

 

Thanks for all your effort, Trebor. Your OCD is sincerely appreciated.

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Perfect. That exactly matches the colors on my CRT with the tint adjusted a few notches toward red. Now if I could fingure out how to adjust the composiite video in my 7800 to do this for me, I could stop being so OCD about this as well.

 

Thanks for all your effort, Trebor. Your OCD is sincerely appreciated.

 

Not to drive your OCD nuts (Or at least not worse than mine :-D ), but one of the reasons that palette (set) became obsolete (IMHO), and I became more avid for a technically accurate palette is due to this:

 

post-18-0-73226300-1357159269.png

 

Notice two things. One thing *really* stands out, The color of INKY is wrong. It is way too green. Ironic enough, as you may think that a red push palette should not push a stronger green. However, that is just it, when you are properly calculating a palette pushing red against an entire color set, not just hand-picking or selecting a row of colors or one specific color, you have to accept all the changes made to the palette during any and all adjustments.

 

In this case the too green Inky, along with the pinkish tint to that maze, told me it was wrong. Bob's Pac Man Collection is supposed to be a bluer INKY and the first two boards are more like a desaturated orange-like color than a pink.

 

If you try the DEFAULT palette....

post-18-0-28412200-1357159589.png

...or even the VIBRANT one...

post-18-0-33948900-1357159652.png

 

Those are the proper range of colors. A bluer INKY with a more orange than pink maze.

 

However, I am working on it. I am trying to strike a properly calculated/properly adjusted palette, that has those "Commando" brown/greens, "Donkey Kong/Dig Dug" browns, along with a properly saturated red/orange hue and of course more blue than green "Inky", that is all possible to tune/set on a CRT television. It will be similar in brilliance to the EX and VIBRANT palette but within an approrpriate (and possible) color palette configuration.

 

As a side note, and please don't take any of this as discrediting your results, but if you have Pac-Man Collection as part of your cartridge collection (And you really should...it is amazing), on your 'real' 7800, can you please double check that INKY is not producing that kind of green as seen in the EX palette? If your 7800 and TV combination does, fantatsic, you're all set :thumbsup:

 

Unfortuantely, it has been my experience and the feedback of others which pointed the palette as not being possible or 'properly' tinted due to that INKY incident alone. There are other factors too for some other games. I need to pull some of my reference notes.

 

Believe me, for as many palettes as I have posted, there are dozens more which I knew off the bat were wrong and were not posted, It's hard to keep track of all of them sometimes. And if nothing else could ever come of it, I'm just glad we have 'NTSC_A7800_RAW.pal' for exactly what the 7800 raw video puts out, and 'NTSC_A7800_YUV_DEFAULT', for the non-bias YUV/YIQ conversion of the RAW RGB palette.

 

Anything else can be manipulated, tweaked and tried until satisfied. ;)

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Ha!

 

Well then this will send your OCD into flipping jumping jacks:

 

Here's a screen cap of Pac-Man Collection using the last palette you posted, NTSC_R08EX_CPS, and then an Arcade PAc-Man screen cap from the latest version of MAME.

 

As you can see, The red-push adjusted palette looks MUCH closer to the Arcade version than the default 7800 output does.

post-34823-0-37154500-1357227644_thumb.jpg

post-34823-0-86214400-1357227644_thumb.jpg

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That is an interesting comparison between Arcade and NTSC_R08EX_CPS, 7800 Emucoder. However, I believe a better comparison would be a screen capture from an CRT TV running the Pac-Man Collection cart rather than the Arcade game running under MAME.

 

Not looking to offend, and glad NTSC_R08EX_CPS works for you, just trying to offer more variety and why for some it doesn't provide what their 7800 and an actual CRT television would provide in terms of colors.

 

Nonetheless with all of the above in mind, here is the reddest possible palette without going too extreme and ridiculous. Again, nothing is hand-picked or manually chosen. We started with NTSC_A7800_RAW (The actual raw video from an NTSC7800), factored in the default YUV conversion settings/palette, and then worked from there in making adjustments including saturation, contrast, brightness, RGB weight factors and gamma.

 

I already have another WIP palette, but wanted to get this out there for those who want a considerably saturated, very red pushed palette.

 

Here's the palette:

NTSC_A7800_YUV_OD_300.zip

 

Here's the color chart:

post-18-0-09314700-1357228968_thumb.png

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Thanks again for all your effort. At this point I just chalk it up to the fact that some of the 7800 game devs were either just lazy, color blind, or were working on a dev station that had a different palette wihtout playtesting on a real 7800 console, because clearly with the YUV default you've made, a lot of them are correct, but a few are just WAAAY off. (and that is how they look on a real 7800 also)

Edited by 7800 Emucoder
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As you can see, The red-push adjusted palette looks MUCH closer to the Arcade version than the default 7800 output does.

 

Just wanted to clarify too that I'm not denying the accuracy of that statement. The default YUV palette (NTSC_A7800_YUV_DEFAULT) is again an exact as possible formed palette based from the RAW video coming from an NTSC A7800 and converted to YUV. We are not converting to Arcade RGB, and it does not factor in any adjustments many people would make to their televisions. My disatisfaction with NTSC_R08EX_CPS (and related palettes) is a result of it not using the correct RAW base.

 

An essential accuracy to the 7800 palette is the 180 degree colorburst. It is completely disregarded and was not factored into making the "NTSC_R08EX_CPS" palette or any in its related family set. That technically correct adjustment did not start to be used in any of the palettes posted until around when the RAW one was established.

 

If you load the Color Demo Rom into the Prosystem emulator with the NTSC_R08EX_CPS palette look at the first 2-3 columns for rows $1 & $F. It is a solid brown color with no green at all present. That disregards the 180 colorburst completely. Despite the latest palette posted (NTSC_A7800_YUV_OD_300) being even redder than NTSC_R08EX_CPS, look at the color chart posted and note the same color squares mentioned. See how it starts very green (A result of the 180 degree colorburst setting) and then gradually turns over to a redder color. That properly reflects the red push/tint against the accurate colorburst of an 7800.

 

I think what I should have done (And actually will do) is match NTSC_R08EX_CPS as closely as possible with the 180 degree colorburst factored in. The hopefully should provide you, and anyone else interested in the red pushed EX palette, one that reflects better the conversion of the 7800 raw video to the YUV/CRT TV colors you experience.

 

Although, let me also state that anything is possible. There are millions of televisions and personal perferences that factor into these palettes and that is why I rather all this palette creation go away, and have all 7800 emulators offer NTSC color simulation. Then everyone and anyone can tweak until their heart is content.

 

I hope this helps 7800 Emucoder and any one else reading why the continued palette postings and the overall evolution of the palette creation, particularly from the NTSC_ACCURATE, EX, and similar palettes which were created earlier in this process. The end results may seem similar, but yet again it is my OCD trying to get this as technically correct as possible while also trying to provide subjective options and personal perference ones (Especially now that all objective angles have been covered as best as possible with the RAW and YUV_DEFAULT palettes).

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Here is a technically accurate while offering a substantial gain to red influence and decrease to green via equalized distribution of the RGB values palette for Atari 7800 emulators.

 

Remembering what the 7800 outputs [The 'RAW' palette], including the 180 degree color burst, bumped up to the color correction factor of going from that raw RGB to YUV/YIQ [The 'YUV DEFAULT' palette], and then an even redistribution of all RGB values to better match a CRT television...In the spirit of the previously offered 'EX' family palette set, here is NTSC_A7800_YUV_EX:

NTSC_A7800_YUV_EX.zip

 

The respective color chart:

post-18-0-64449200-1357570149_thumb.png

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You are sooo cool for doing this :)

Great work!

 

You know me Bob, I'm a little finicky when it comes to color (Remember my whole Inky looks "too green" episode? :-D )

 

Believe it or not, it was your game (Bentley) that finally put me over the edge in having to do something. Taking all those screenshots thinking (and being told by some) that those colors were very accurate when really they were pretty way off from most standard/normal display devices, coupled with re-establishing my 'classic' collection along with two composite mod and two regular RF 7800's, with a little icing on the cake with the dispute over Yurkie's mod and the 'Commando green'...I had to get to the bottom of it.

 

Who knows, maybe this will lead to me actually looking into hacking and eventually programming 7800 games someday.

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To help centralize, summarize, and simplify what is available regarding palette selection here's a brief summary:

 

 

You want the raw color output of a 7800. Likely also what you may experience with many of the 7800 composite video mods on today's digital televisions without bias...

This is it: NTSC_A7800_RAW.pal

 

 

You want the colors as provided on a typical CRT traditional television with everything in the neutral position as closely as possible to what would be produced via RF output without bias...

This is it: NTSC_A7800_YUV_DEFAULT.pal

 

 

You want the colors with a very strong red-push in comparison to the "DEFAULT" palette, overall focusing more on minimizing the presence and value of green towards red

This is it: NTSC_A7800_YUV_VIBRANT.pal

 

 

You want extreme rich and deep colors, super saturated while boosting red heavily. Appears more red than "VIBRANT", due to gamma turned up and contrast and brightness adjusted as well...

This is it: NTSC_A7800_YUV_OD_300.pal

 

 

You want the default 7800 colors as provided on a typical CRT traditional television with a stronger yet balanced red/warm push and an equal redistribution of blue and green accordingly…

This is it: NTSC_A7800_YUV_EX.pal

 

 

NEWLY ADDED: Your display device is warm and well saturated. It is more than VIBRANT, but not Over-Driven. Colors are brilliant and strong throughout. However, contrast and brightness remains normal...

This is it: NTSC_A7800_YUV_SPLENDID.zip

 

 

NEWLY ADDED: You want optimized red, blue, and green ratios, with an increased saturation from DEFAULT, but less than SPLENDID. A convergence of all YUV palettes posted...

This is it: NTSC_A7800_YUV_CONVERGE.zip

 

 

As mentioned previously, the "YUV" palettes are the only ones which start with the technically correct raw values for video output of an Atari 7800 and then adjustments are performed. Prior palettes started with either missing one or many of the known calculated base values of the system's palette, or the base value was incorrect; in other words, making adjustments from a wrong start point.

 

Again as always, hope this helps and is found useful.

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Attached is the DEFAULT family set containing six palettes. We go from the RAW video to DEFAULT non-bias and next cross over to the only points where exact proportional increase distribution of both hue and saturation can take place on a scale of 1-100. 33%, 50%, 67%, and then 100% increase from DEFAULT.

 

Probably the most accurate varied selection available and likely the best of what has been posted so far. However, your millage may vary depending on display and personal preference.

 

Grab the DEFAULT family set of palettes here: DEFAULT A7800 PALETTE SET.zip

 

Color Charts and screen captures attached in the following order...

RAW --> DEFAULT --> DEFAULT33 --> DEFAULT50 --> DEFAULT67 --> DEFAULT100:

 

Color Charts: DEFAULT FAMILY.zip

Screen captures: DEFAULT PALETTE SET.zip

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33 and 50 seem to have a good amount of RED, so browns look nice, but greens look too blue in each of these... at least on my monitor.

 

So far, from what I've seen when playing my 7800 on this LCD and the Sony Trinitron CRT back home, your REALNTSC palette is closest to the real thing with usual TV color settings.

 

Also, I've noticed that with each of my 7800s, colors change after the system has time to warm up a bit. For example: when I first turn it on, the Tank Command color hack dirt has a slightly greenish hue. But, after the 7800 has been on for a few minutes, it becomes a nice brown like we'd expect.

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Hi Kevin,

 

Thanks for the feedback. One of my work monitor's has a strong blue push; more so in its relation to red than green. So much so, that most 'purples' or what shows to be purple for the 7800 on all other displays I have seen, always contains much more blue and usual does not look purple at all. It impacts green pretty badly too - Mostly playing hijinks with Inky's color under Pac-Man collection. It is almost impossible to make Inky turn (incorrectly) too greenish regardless of any palette I try, and always looks bluer than it does on any other display.

 

A display's capabilities including the way (if) it handles or utilizes dithering can always impact the color it provides in certain combinations and scenarios. The display I mentioned before from work is actually a manufactured one by Samsung on a Dell laptop and uses a form of dithering which obviously accounts for the differences I see on it in comparison to any other display.

 

The NTSC "ACCURATE" (and "EXACT") line posted earlier from the other thread has an issue in relation to Atari 7800 that the colorburst (180 degrees) was not in place anywhere. From the technical documentation available it would make any palette derived from it near impossible on an actual 7800 system.

 

Interestingly enough, though, it has been stated that "most" factory issued 7800's were set to this configuration, and considering how ultra sensitive that dial is on the system (Even the most minimal turn causes a color change), it would not surprise in the least bit that many units went out from the factory perhaps even several degrees off from 180 (If I recall correctly, the accurate and exact palettes ranged more in the 170's to upper 160's region).

 

Lastly, and just for the sake of covering all bases, the ACCURATE palette also did not have the default saturation and contrast start point either (But that of course is more than (and) likely adjusted on the consumer side.

 

That being said, and funny enough you mention a Sony display (and how it harmonizes with what I am about to write), what I love about that work display I mentioned earlier is that for any C64 emulator, it provides a color palette (Especially a blue showing over purple) that I fondly recall with many emulator's 'default' selection. It winds up this is the case: http://en.wikipedia.org/wiki/File:C64_ntsc_cxa2025.bmp.png

 

Sony utilized a different NTSC decoder matrix. When you look at its color especially the blue/green/purple, it has a brighter look with a bluer and greener bias than the other matrix of a more red influenced/purple heavier interpretation of blue. That is the palette set, though, I recall on my C64 usage in my younger days, and I swear it was on more than just a Sony display as well.

 

Nonetheless, I am happy the ACCURATE palette works for you in providing what you recall. I favor and praise higher these last set of palettes not because it is necessarily what I recall or my preference, but for it being more technically sound. The proportion and increase of saturation and red, blue, green values are near exact by stated percentage.

 

Though again, as I mentioned before anything is possible. I'm glad we have the RAW and basic DEFAULT palette as those are a non-bias calculated palette of exactly what is expected from the raw video coming out of the back of the 7800 to a direct color correction via RF output on a typical CRT TV display. Anything and everything else becomes millions of different combination and possibilities.

 

Just hoping my OCD on this will let it go...eventually. I'm nowhere near even several hundred palettes (yet)...Millions would sure take a lot more time...lol.

 

What would really be the best solution is that NTSC video generation with all the tweaking imaginable. Fingers crossed and here is to hoping that more 7800 emulators offer video options like MESS in allowing users to really fine tune the colors, brightness, contrast, saturation, artifacts, etc.

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