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My 7800 HDMI mod


IJoeG

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After I installed Bryan's UAV board I was amazed at how much better the picture was. I had done both the Best Electronics composite and the Longhorn Mod and neither had anywhere near the picture quality as the UAV board connected through S-video. Then I connected it to an HDMI converter and the difference was amazing.

 

What I wasn't happy with was having so many wires and connections to hook up my 7800. So after some tinkering this is what I came up with. I'm pretty happy with how it came out with very little modding to the plastic case. My only concern was that the extra amp draw might be to much and I might have to upgrade the power supply. So far after several hours of playing that doesn't seem to be an issue. I was also pretty happy the metal shielding still fit back in place.

 

I'm interested in what you all think. I might change the wire to ribbon cable to give it a cleaner look but for now i'm just enjoying playing it. Bryans board really is amazing.

 

The case was really dirty, it cleaned up a lot nicer then in the pic

 

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The switch to the left of the HDMI jack is to select between 480, 720 or 1080

 

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Testing after I removed all the unnecessary components from the board before I tried installing installing it.

 

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Can you post some pics of the video output onto your HDMI based screen? Looks cool.

 

 

Can tell this was a lot of work... a lot of wires, soldering, etc. but looks amazing! Secured the HDMI board nicely too. Whole job looks real professional.

 

I too am interested in seeing what the output looks like...

 

 

Thank you, the work was mostly just trying to figure out where it would fit and what would have to be removed. I had to dremel away about an 1/8" of the hdmi board so it would fit tighter to the cartridge slot on the right.

I took some pics but I'll take some more after dark. it was too bright in the room and there was too much glare on the TV.

The blur you see is from the camera. colors are too bright for my iPhone. There is no ghosting at all, its just the camera, the picture is very sharp and the colors are bright.

 

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Wow, the detail and clarity!!

 

How about a pic of Commando's title screen? Your color phase pot may need slight adjusting... or perhaps the system wasn't warmed up? See too much green on the playfield, where there should be some brown dirt. Especially interested in seeing the difference between his arms (should be brown), his uniform (should be green) and the title gold/yellow. If you don't have a 7800 color bar generator, it's what I've used to calibrate my 7800's. :)

 

Though when A/V modding a 7800,... dialing in/getting the colors right on this particular game can end up in mixed results that adversely affect other titles. The joys of A/V modding! ugh

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How about a pic of Commando's title screen? Your color phase pot may need slight adjusting... or perhaps the system wasn't warmed up? See too much green on the playfield, where there should be some brown dirt. Especially interested in seeing the difference between his arms (should be brown), his uniform (should be green) and the title gold/yellow. If you don't have a 7800 color bar generator, it's what I've used to calibrate my 7800's. :)

 

Though when A/V modding a 7800,... dialing in/getting the colors right on this particular game can end up in mixed results that adversely affect other titles. The joys of A/V modding! ugh

 

The overly green looking Commando ground is not impacted by the color pot adjustment inside the console. It comes from Hue $1x range of the console which is modified strictly by the display device's tint/hue setting.

 

This unfortunately is a common issue with certain hues respecting how they appear under a CRT versus a modern display at default settings.

 

Check out the thread regarding Bryan's video mod in this forum for more details.

 

 

 

There are two ways to 'fix' the issue:

 

1. Adjust the tint/hue setting of the display.

2. A video mod which substitutes RGB palette values for the colors, as utilized in such video mods as NESRGB and 2600RGB. A discussion thread for the NESRGB is here, and another thread centers around the Atari 2600 one.

 

Hue $1x range should be in the gold/golden range on NTSC Atari consoles. A gold/golden range leans more brown for darker luminance values and more yellow for lighter luminance values. If there are green/chartreuse hues seen instead, the display is not showing colors as intended for the console or the game design.

 

Here is Commando under the same console, first on a CRT, next on an LCD, both displays at default tint/hue settings:

 

post-18-0-22743700-1502056371_thumb.pngpost-18-0-64659300-1502056379_thumb.png

 

 

 

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Wow, the detail and clarity!!

 

How about a pic of Commando's title screen?

 

Like I mention earlier, the blur around commando is from the camera and not on the TV screen.

 

post-52591-0-05040200-1502066380.jpg

 

Commando is just about the only game I notice a difference and to be honest I'll take the crisper picture even if it is green. It's still a great picture, he's just running through a grassy field. ;-) Bently Bear himself is also slightly green instead of brown don't notice any other color changes in the Bently game. The blues are bright and sharp its a really colorful game with the UAV board.

 

The pics I put up are taken on my plasma TV, I get more of the browns on my LCD TV.

 

So this converts MARIA's output to a 60hz HDMI signal?

 

I'm not smart enough to know how it works, I'm just dumb enough to take perfectly good electronics apart and see what I can figure out. ;-)

 

I used Bryan's UAV board and directly soldered it to a Startech VID2HDCON S-Video to HDMI converter. I had to remove parts from both the converter and the Atari. Also had to cut down the converter board a little.

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Like I mention earlier, the blur around commando is from the camera and not on the TV screen.

 

IMG_4870.JPG

 

Commando is just about the only game I notice a difference and to be honest I'll take the crisper picture even if it is green. It's still a great picture, he's just running through a grassy field. ;-) Bently Bear himself is also slightly green instead of brown don't notice any other color changes in the Bently game. The blues are bright and sharp its a really colorful game with the UAV board.

 

The pics I put up are taken on my plasma TV, I get more of the browns on my LCD TV.

 

 

I'm not smart enough to know how it works, I'm just dumb enough to take perfectly good electronics apart and see what I can figure out. ;-)

 

I used Bryan's UAV board and directly soldered it to a Startech VID2HDCON S-Video to HDMI converter. I had to remove parts from both the converter and the Atari. Also had to cut down the converter board a little.

so you're using the 7800 power supply to power the HDMI board too? How does it do with some of the more complicated games like ballblazer, commando, pitfall II, or ninja golf?
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so you're using the 7800 power supply to power the HDMI board too? How does it do with some of the more complicated games like ballblazer, commando, pitfall II, or ninja golf?

 

Yeah he really ought to think about putting a higher amp voltage regulator in there to try and compensate. My guess is that the current VR only being rated for 1amp (And I've heard some are only 500ma) will get way too hot eventually and begin to cause issues.

 

I use this exact same method, only I have many S-video output consoles now and run them all through a multi AV out and that in turn, into one of these s-video/composite to HDMI converters to my LCD. I was able to adjust the colors on mine a bit better on my LCD and yes if you drop the green tint and increase the red tint on your LCD tv you can get it nearly on. But...doing that will throw the colors off on most other things you view like in my case, every other console I have connected. So I just left it with the green grass field on mine as well.

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so you're using the 7800 power supply to power the HDMI board too? How does it do with some of the more complicated games like ballblazer, commando, pitfall II, or ninja golf?

 

Played the games you mentioned above with no issues. They look great and play just fine.

 

 

Yeah he really ought to think about putting a higher amp voltage regulator in there to try and compensate. My guess is that the current VR only being rated for 1amp (And I've heard some are only 500ma) will get way too hot eventually and begin to cause issues.

 

 

 

As I mentioned in my original post I was concerned and prepared to change out the power supply. After testing it for several hours playing games and just leaving it turned on for awhile it seems to be fine. No heat issues beyond normal on the game or the power supply. As you mentioned above some power supplies are 500ma, so the system must draw less then 500ma. I think the 1amp power supply is going to handle the extra draw of the converter just fine.

 

The only issue I need to fix right now is the converter takes about 10 seconds to connect after I turn on the 7800, the screen is black during that time. I miss the atari start up screen. I'm going to move the 5v wire from the converter over so it powers up as soon as the 7800 is plugged in. That way when I power on the machine it will start up normally.

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Played the games you mentioned above with no issues. They look great and play just fine.

 

 

 

As I mentioned in my original post I was concerned and prepared to change out the power supply. After testing it for several hours playing games and just leaving it turned on for awhile it seems to be fine. No heat issues beyond normal on the game or the power supply. As you mentioned above some power supplies are 500ma, so the system must draw less then 500ma. I think the 1amp power supply is going to handle the extra draw of the converter just fine.

 

The only issue I need to fix right now is the converter takes about 10 seconds to connect after I turn on the 7800, the screen is black during that time. I miss the atari start up screen. I'm going to move the 5v wire from the converter over so it powers up as soon as the 7800 is plugged in. That way when I power on the machine it will start up normally.

 

I wasn't talking about the power supply itself. I was talking about the 7805 voltage regulator inside the 7800. It is attached to the metal black piece behind the cartridge port. That is what is actually supplying the +5 to the system and thus your HDMI converter. You just need to get a higher output version to put in place of the original to make sure it outputs enough current for everything.

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I wasn't talking about the power supply itself. I was talking about the 7805 voltage regulator inside the 7800. It is attached to the metal black piece behind the cartridge port. That is what is actually supplying the +5 to the system and thus your HDMI converter. You just need to get a higher output version to put in place of the original to make sure it outputs enough current for everything.

 

 

Sorry I miss understood when you said power supply. I was concerned about actual power supply being under amped to handle both. I'll look into changing that out. I'd rather be safe then sorry. Any suggestions on what to upgrade it to?

 

Thanks for your help, it was your suggesting I use the S-Video to HDMI instead of the composite that got me started tinkering with this.

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Sorry I miss understood when you said power supply. I was concerned about actual power supply being under amped to handle both. I'll look into changing that out. I'd rather be safe then sorry. Any suggestions on what to upgrade it to?

 

Well, it depends on what the 7800 current requires plus the HDMI converter. But I would imagine a 2amp output is better than the original..

 

http://www.mouser.com/search/ProductDetail.aspx?r=511-L78S05CV

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You need to start by finding out what the amperage is on the power supply for the HDMI converter. I believe the 7805 tops out at 1.2amps anyway.

 

The amperage on the power supply is 1 amp. I can't find anywhere that says what it actually draws. Is it possible to double up two 7805's?

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I have two custom settings available on my TV. So I adjusted the settings in one of them for Commando. Now when I want to play Commando I can just switch over to Commando mode. ;-)

 

It may be worth it to try Dig Dug under "Commando mode" too. Any game that utilizes the Hue $1x range significantly (2 of the 4 layers of ground for Dig Dug), would likely improve in appearance.

 

Do any of the resolution settings (480/720/1080), automatically provide/preserve a 4:3 aspect ratio? No big deal as that usually can be managed manually by a simple button press on the display's remote; just curious though.

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To state the obvious, there's color artifacting in those Tower Toppler screen shots, though it's a bit weak.

 

Artifacting is only possible when chroma and luma are mixed together in a composite signal. It does look like the s-video output is being sent to the HDMI circuit, so I can only assume that the HDMI board mixes chroma and luma to avoid having separate processing on composite video and s-video.

 

While this opens the door to some unintentional color artifact effects (look at the vertical borders in Astro Blaster - where the color starts and ends has a slightly different color, with some pink being added to the trailing edge. Same can be seen in the score font.) it looks pretty minimal here. I'd rather this result, than a full loss of intentional artifacting.

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