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Atari 2600 RGB mod


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#351 Thomas Jentzsch OFFLINE  

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Posted Wed Aug 2, 2017 9:11 AM

They all botch it to varying degrees, in some cases to the point of rendering certain games unplayable.

Yes, but a good scaler is possible. The VCS signal contains nothing which is impossible to scale correctly.



#352 ZylonBane OFFLINE  

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Posted Wed Aug 2, 2017 9:16 AM

The biggest differences are interlacing and 30Hz flicker. The 2600 used these analog display characteristics for purposeful effect in certain games, not just as a hardware limitation. This cannot be accurately duplicated using digital graphic displays. You're getting an approximation at best, and I've never seen an accurate representation of this, either through a dedicated scaler, or using a display's integrated scaler. They all botch it to varying degrees, in some cases to the point of rendering certain games unplayable.

 
Yeah it's almost as if the best HDMI scaler for the 2600 would be one created specifically for the 2600, instead of relying on an external generic box.
 
And the notion that such effects are impossible to replicate on modern TVs is ludicrous. HDMI supports 60Hz video, so 30Hz flicker can be represented perfectly well.



#353 DrSidneyZweibel OFFLINE  

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Posted Wed Aug 2, 2017 9:24 AM

 
Yeah it's almost as if the best HDMI scaler for the 2600 would be one created specifically for the 2600, instead of relying on an external generic box.
 
And the notion that such effects are impossible to replicate on modern TVs is ludicrous. HDMI supports 60Hz video, so 30Hz flicker can be represented perfectly well.

The problem is not in the relative Hz of the signal, but the internal mechanics of the Display itself. I've never once seen one of these HD displays pull this off, because they all take the 30Hz flicker and interpolate and convert it to a progressive signal. I'd love to see it done properly.



#354 skooter OFFLINE  

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Posted Wed Aug 2, 2017 9:40 AM

 

Clearly you have no idea what you're actually talking about. Otherwise you'd explain what you mean instead of parroting your little catchphrase over and over. Like, maybe you could explain to us the difference between a 2D pixel and a 3D pixel.

 

I think the same about you. I never said there were 3D pixels. I said there is difference between 2D graphics and 3D graphics.

 

2D graphics are better upscaled by just replicating pixels, like OSSC and Framemeister (Picture mode) actually do. At least most people prefer it that way, blocky, not blurry. Emulators actually have specific filters for 2D graphics, "eagle" and "HQ" stuff.

 

If you apply the same approach for 3D graphics, they don't look good. 3D graphics are better upscaled by interpolating pixels, like TVs actually do. That's why filters for 3D graphics are different.



#355 Keatah ONLINE  

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Posted Wed Aug 2, 2017 10:02 AM

 For the love of god, read the 2600 RGB mod description page:
 
"The various luma outputs from the TIA, in addition to the colour data stored is then used to create a RGB version of the original video signal. Essentially, the board creates the RGB video signal by bypassing the colour generation logic in the TIA."
 
There is no analog hole in the 2600 RGB mod. It only uses raw digital data from the 2600.

 

The analog hole is moved outside of the VCS. Still have to convert it back to digital. So again, why bother? Just build the digital signal in the first place.



#356 Keatah ONLINE  

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Posted Wed Aug 2, 2017 10:13 AM

I think the same about you. I never said there were 3D pixels. I said there is difference between 2D graphics and 3D graphics.

 

2D graphics are better upscaled by just replicating pixels, like OSSC and Framemeister (Picture mode) actually do. At least most people prefer it that way, blocky, not blurry. Emulators actually have specific filters for 2D graphics, "eagle" and "HQ" stuff.

 

If you apply the same approach for 3D graphics, they don't look good. 3D graphics are better upscaled by interpolating pixels, like TVs actually do. That's why filters for 3D graphics are different.

 

There really is no such thing as a 2D pixel or 3D pixel. When the data for drawing the image hits the framebuffer it is laid out in an X,Y fashion, strictly "2D".

 

The 3D pixel is a higher concept manipulated in software (and hardware). It final phases of rendering certain artifacts may be produced, certain patterns in the final x,y matrix. And these artifacts and patterns can be made more attractive or more ugly depending how their algorithms resonate.

 

Eagle and Super Eagle and 4xHQ and all the crotchety bullshit apply to a planar 2D matrix. They're all fugly little bastards that are a blight on the options screen and do nothing attractive.

 

Mip Mapping and texture filtering and tessellation are higher level 3D functions and apply to 3D pixels only. 3D pixels exist as an abstracts in an API like OpenGL. It's all x,y 2D when it leaves the videocard's framebuffer to go to the monitor.



#357 ZylonBane OFFLINE  

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Posted Wed Aug 2, 2017 10:55 PM

The problem is not in the relative Hz of the signal, but the internal mechanics of the Display itself. I've never once seen one of these HD displays pull this off, because they all take the 30Hz flicker and interpolate and convert it to a progressive signal. I'd love to see it done properly.

 
Yes, you've never seen it done properly because most scalers weren't designed to deal with a nonstandard 240p picture that uses lots of flicker. That's why I keep saying that an HDMI scaler designed explicitly for the 2600's display characteristics would be the way to go. So stop confusing the capabilities of scalers with the capabilities ot modern TVs.

 

2D graphics are better upscaled by just replicating pixels, like OSSC and Framemeister (Picture mode) actually do. At least most people prefer it that way, blocky, not blurry. Emulators actually have specific filters for 2D graphics, "eagle" and "HQ" stuff.
 
If you apply the same approach for 3D graphics, they don't look good. 3D graphics are better upscaled by interpolating pixels, like TVs actually do. That's why filters for 3D graphics are different.


What you've stated here is pure personal opinion, not fact. Emulators can keep things sharp, but they also have options to make the picture more "analog", with simulated scanlines, blur, chroma bleed, phosphor persistence, etc. People like both. Ditto for 3D graphics-- I hate soft-looking polygon edges. Give me sharp any day.



#358 DrSidneyZweibel OFFLINE  

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Posted Thu Aug 3, 2017 6:19 AM

 
Yes, you've never seen it done properly because most scalers weren't designed to deal with a nonstandard 240p picture that uses lots of flicker. That's why I keep saying that an HDMI scaler designed explicitly for the 2600's display characteristics would be the way to go. So stop confusing the capabilities of scalers with the capabilities ot modern TVs.


The thing is, we're talking about a cheap $30 a $50 video mod for a 40 year old video game console. If HD TV designers couldn't even get this right on the scalers in high end HDTVs that cost several thousand dollars, how much do you think Atari nerds are going to be willing to pay for a video mod with a more sophisticated scaler than the one in a $5000 high end HD set?

I like your idea. It doesn't sound feasible.

#359 Thomas Jentzsch OFFLINE  

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Posted Thu Aug 3, 2017 6:26 AM

If HD TV designers couldn't even get this right on the scalers in high end HDTVs...

I bet they didn't even try.

#360 Keatah ONLINE  

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Posted Thu Aug 3, 2017 8:21 AM

They don't. It isn't a priority.



#361 DrSidneyZweibel OFFLINE  

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Posted Thu Aug 3, 2017 11:35 AM

I bet they didn't even try.

Because doing so in an affordable scaling unit for a commercially sold TV would negatively impact the ability to successfully scale progressive images from lower resolutions to 720/1080/2160. Pixel interpolaters in HD scaling units are designed exactly to present a uniform, single resolution/frequency picture. To accurately replicate 30hz flicker as created by the kind of analog video of an Atari, you would need a separate processing channel/interpolater to process the 30Hz elements  alongside the 60Hz standard elements. You're talking about a video mod for an atari that can create a transparency mask for the 30hz signals it receives, so as to display them as a partially-transparent image on a progressive output.

 

It CAN be done. But it would be quite costly to implement, and likely wouldn't fit inside an Atari shell, unless you go with some kind of FPGA/Raspberry Pi device to process the image this way, which is far more involved than a few transistors, resistors, and a filtering IC, like standard analog video mods.

 

at that point you're going through so many layers of external vido signal modification and processing, you would lose any perceived or measurable latency advantages of using real hardware over emulation.



#362 DrSidneyZweibel OFFLINE  

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Posted Thu Aug 3, 2017 11:37 AM

They don't. It isn't a priority.

please stop speaking authoritatively about subjects you're guessing about.



#363 Thomas Jentzsch OFFLINE  

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Posted Thu Aug 3, 2017 11:55 AM

Because doing so in an affordable scaling unit for a commercially sold TV would negatively impact the ability to successfully scale progressive images from lower resolutions to 720/1080/2160.

I don't see why.
 

Pixel interpolaters in HD scaling units are designed exactly to present a uniform, single resolution/frequency picture.

Exactly like a correct 2600 signal.
 

To accurately replicate 30hz flicker as created by the kind of analog video of an Atari, you would need a separate processing channel/interpolater to process the 30Hz elements  alongside the 60Hz standard elements. You're talking about a video mod for an atari that can create a transparency mask for the 30hz signals it receives, so as to display them as a partially-transparent image on a progressive output.

Why that? 30 Hz flicker is not a special signal. The signal is still 60Hz, 240p, just some elements being displayed only every 2nd frame. Special processing here would be only required if you want to "improve" the picture.

Edited by Thomas Jentzsch, Thu Aug 3, 2017 11:57 AM.


#364 Keatah ONLINE  

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Posted Thu Aug 3, 2017 12:07 PM

please stop speaking authoritatively about subjects you're guessing about.

 

Erm, no. It is as plain as day.

 

 

Because doing so in an affordable scaling unit for a commercially sold TV would negatively impact the ability to successfully scale progressive images from lower resolutions to 720/1080/2160.

 

It would have no impact, because, it could manually be selected in a menu option which then patches in the necessary circuit or software module. And the software costs (or physical circuit costs) would be nil to the consumer. It would be spread over hundreds of millions of televisions.

 

The menu option costs nothing beyond a couple of hours of developer time. You clearly don't understand how things can be constructed.

 

Modern television manufacturers are NOT interested in supporting pre-Xbox & pre-PlayStation consoles. Get over it.



#365 Great Hierophant OFFLINE  

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Posted Thu Aug 3, 2017 1:38 PM

Modern television manufacturers are NOT interested in supporting pre-Xbox & pre-PlayStation consoles. Get over it.

 

Make that PlayStation 2 consoles, the original PlayStation 1 (and N64 and Saturn) had a lot of 240p action going on.



#366 Keatah ONLINE  

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Posted Thu Aug 3, 2017 2:00 PM

Sounds fair.



#367 ZylonBane OFFLINE  

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Posted Thu Aug 3, 2017 7:41 PM

please stop speaking authoritatively about subjects you're guessing about.

 
 Oh, irony.



#368 skooter OFFLINE  

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Posted Tue Aug 8, 2017 7:46 AM

Draconian - 2600RGB + Framemeister again. Now with Firebrandx's profile:

 

 

Pressure Cooker (2600RGB + Framemeister + Firebrandx's profile):

 

 

Pole Position (2600RGB + Framemeister + Firebrandx's profile):

 



#369 ubersaurus OFFLINE  

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Posted Tue Aug 8, 2017 7:52 AM

What do his profiles do, exactly, for the 2600 vs. the defaults? The only changes I made were to deal with the sync problems.



#370 skooter OFFLINE  

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Posted Tue Aug 8, 2017 7:57 AM

His profiles use integer-based resize.

 

Which sync problems did you have? And which settings did you use to fix?

 

Most games I tried here worked with the default sync settings. The exceptions was Tapper and Video Pinball, but I couldn't fix them through the settings.



#371 Keatah ONLINE  

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Posted Tue Aug 8, 2017 11:36 AM

Looks almost as good as emulation!



#372 ubersaurus OFFLINE  

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Posted Tue Aug 8, 2017 12:12 PM

His profiles use integer-based resize.

 

Which sync problems did you have? And which settings did you use to fix?

 

Most games I tried here worked with the default sync settings. The exceptions was Tapper and Video Pinball, but I couldn't fix them through the settings.

Ah, I just set mine to 720p and it seems to work just peachy on my end. I was just curious if he had something to deal with the overscan.

 

If I remember right I went into sync settings and turned the resync option from 0 to 100. It gives me problems with Video Chess while the computer is thinking, but that's been it. I haven't messed with it too much since, there may be better options to fiddle with.



#373 ZylonBane OFFLINE  

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Posted Tue Aug 8, 2017 7:37 PM

So is it the Framemeister or your video capture setup that can't maintain a steady frame lock, messing up the interlace effect on Draconian's title screen?



#374 skooter OFFLINE  

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Posted Tue Aug 8, 2017 7:44 PM

So is it the Framemeister or your video capture setup that can't maintain a steady frame lock, messing up the interlace effect on Draconian's title screen?

 

Make sure you are watching in 1080p60.



#375 ApolloBoy OFFLINE  

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Posted Wed Aug 30, 2017 11:38 AM

Here's an example of a 2600RGB mod on a Jr., since nobody hasn't really shown one in this thread yet. Tim's guide recommends mounting the connectors on the side, but I decided to go for a more challenging install and mounted them on the back. I removed the RF jack, widened the cutout for it and then mounted an 8-pin mini-DIN jack in its place. I had to do a bit of trimming on the top half as well, but the nice thing is that the top shell puts a bit of pressure on the mini-DIN and adds more rigidity. The pause/palette selection button is mounted where the channel select used to be.

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