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The UAV Rev. D Video Upgrade Thread


Bryan

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Hi.  So I just finished installing a UAV mod in one of my 6 Switch Atari 2600s and the colors are super bright, and just don't look right.  I lifted pin 6 on the TIA and all of the wires are attached exactly as pictured in the instructions.  Is there an additional step that I missed?  Thanks!!

Edited by shear_xear
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58 minutes ago, shear_xear said:

Hi.  So I just finished installing a UAV mod in one of my 6 Switch Atari 2600s and the colors are super bright, and just don't look right.  I lifted pin 6 on the TIA and all of the wires are attached exactly as pictured in the instructions.  Is there an additional step that I missed?  Thanks!!

That picture has a caption that states you should look at the silkscreen on the UAV for correct placement since the UAV in the picture is a rev. C and not a rev. D.  Did you make sure to do that?  

 

Did you do this step as well:

After that, the color signal goes through a 47pF cap and we can tie BLANK to this point instead, but another capacitor is needed in line with the 820 ohm resistor (.1uF is fine). Also, the resistor value can be varied to adjust the amount of saturation. 

 

Also, check continuity. 

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2 hours ago, MacRorie said:

That picture has a caption that states you should look at the silkscreen on the UAV for correct placement since the UAV in the picture is a rev. C and not a rev. D.  Did you make sure to do that?  

 

Did you do this step as well:

After that, the color signal goes through a 47pF cap and we can tie BLANK to this point instead, but another capacitor is needed in line with the 820 ohm resistor (.1uF is fine). Also, the resistor value can be varied to adjust the amount of saturation. 

 

Also, check continuity. 

What do you mean by “look at the silkscreen”?  As for the last step, I think I found the 47pf cap, but where is BLANK coming from?  I can’t locate an 820 ohm resistor; where on the board would this be?   Thanks!

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14 hours ago, shear_xear said:

What do you mean by “look at the silkscreen”?  As for the last step, I think I found the 47pf cap, but where is BLANK coming from?  I can’t locate an 820 ohm resistor; where on the board would this be?   Thanks!

Read Page 6 of the manual and it will detail where the resistor is and how to install the change to go around the colorburst.

 

The silkscreen is on the UAV itself.  You can also see the connections on page 3.

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Hello MacRorie, It is a bit confusing where to put the input for color for Atari 2600 vs Atari 8 bit computers. In the pictures look like we have to have the IN in the green connector, but there is also a TCOL via and I read that is for the 2600 color. 

Could you help us to understand the differences b/w tcol and the color input? 

Could this iinout be used for 8bits Atari computers?

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19 minutes ago, manterola said:

Hello MacRorie, It is a bit confusing where to put the input for color for Atari 2600 vs Atari 8 bit computers. In the pictures look like we have to have the IN in the green connector, but there is also a TCOL via and I read that is for the 2600 color. 

Could you help us to understand the differences b/w tcol and the color input? 

TCOL is for 7800 installs only.

19 minutes ago, manterola said:

Could this iinout be used for 8bits Atari computers?

It was not designed for that and I do not think there is an equivalent on the A8.  Could be made to work, I suppose, but that was not why it was put there.

 

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  • 4 weeks later...
On 1/2/2020 at 4:55 PM, ivop said:

I have this old 800XL motherboard (it's actually my original Atari from '85) and it has all of the video circuitry removed (i.e. everything that connects to lum0-3/color/csync) in one way or the other.

Question is, what do I have to restore to use a UAV in the CD4050 socket? I suppose R41-R45 (the five pull-ups) need to be placed back. Anything more?

 

I'm about to build this into a new casing, and want it to have video-out :)

 

Edit: the casing: https://www.plexilaser.de/Acrylgehaeuse-fuer-ATARI-800XL-Teilesatz

 

This is going to be my main machine for FujiNet development.

 

 

To answer my own question: R41-R45 is not the bare minimum to run UAV of the CD4050 socket. You also need at least L5 (820uH) otherwise it doesn't get any power. While you're at it, might also place back/keep in place C50 (10uF) and C51 (100n) for filtering of the power supply. The rest of the video-out circuit can be removed :)

 

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  • 2 weeks later...
  1. Manual version 1.62, says on page 12: "The first problem is that the Luminance pad (5) is shorted to ground (2) on the bottom". It should say Chrominance instead of Luminance.
  2. As a question, then it says: "BTW, if you remove the 4050, you lose the modulator function." Is that always right for every installation?
  3. Not tested, but if a 4050 is soldered over a UAV, will the UAV and the RF both properly work?  I'm guessing that the quality of the UAV will be reduced with a 4050 soldered on it. Is that right or the quality is not affected?

 

Searching the forum, here someone didn't remove the 4050 and the quality seems to be ok:

https://atariage.com/forums/topic/260267-the-uav-rev-d-video-upgrade-thread/?do=findComment&comment=4054818

 

1031891786_600xl-1.thumb.jpg.55651be47a62072583d4b9a87733c2bb.jpg

 

49353464_600xl-2.thumb.jpg.a2e24191536e2dca446ffe45f363f585.jpg

 

 

Edited by tane
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13 minutes ago, hueyjones70 said:

... and keep the modulator function but why would you want to?

For historical purposes.

 

But after some experiments, I concluded that just the fact of connect the RF modulator, it adds a heavy distortion, so it's best to be removed.

 

Connecting the 4050 doesn't seem to make a difference, but it makes a very slight difference to have individual ground points for each one. (A further experiment with a UAV without the 4050 should be done, and to compare one to one).

 

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22 hours ago, tane said:
  1. Manual version 1.62, says on page 12: "The first problem is that the Luminance pad (5) is shorted to ground (2) on the bottom". It should say Chrominance instead of Luminance.

Thanks.  That was corrected a bit ago.  The manual is now on version 1.8.  If anyone finds any other errors or suggestions, please send them along. I have included a copy here for folks.

22 hours ago, tane said:
  1. As a question, then it says: "BTW, if you remove the 4050, you lose the modulator function." Is that always right for every installation?
  2. Not tested, but if a 4050 is soldered over a UAV, will the UAV and the RF both properly work?  I'm guessing that the quality of the UAV will be reduced with a 4050 soldered on it. Is that right or the quality is not affected?

 

Searching the forum, here someone didn't remove the 4050 and the quality seems to be ok:

https://atariage.com/forums/topic/260267-the-uav-rev-d-video-upgrade-thread/?do=findComment&comment=4054818

 

The 4050 left in place (by whatever means you see fit) does not degrade the quality of the output, per se.  However, additional cables simulataneously being attached does, in some cases, result in degraded signals.  IN the case of the 5200, it is essential on some boards, so this is not a universal statement across all machines.

 

TBA UAV Manual.pdf

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I soldered a socket on top of my 4050, plugged UAV into that. RF, Composite, and S-Video all working great.

 

The UAV sits a little high, but still fits under an 800XL Alps keyboard.

 

(I since gave up on the shield for this machine haha)

post-53052-0-09937800-1525508477_thumb.jpg

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1 hour ago, MacRorie said:

Thanks.  That was corrected a bit ago.  The manual is now on version 1.8.  If anyone finds any other errors or suggestions, please send them along. I have included a copy here for folks.

The 4050 left in place (by whatever means you see fit) does not degrade the quality of the output, per se.  However, additional cables simulataneously being attached does, in some cases, result in degraded signals.  IN the case of the 5200, it is essential on some boards, so this is not a universal statement across all machines.

 

TBA UAV Manual.pdf 38.85 MB · 1 download

Yes I found out that having both composite and s-video plugged in at the same time on the 5200 results in thin vertical bars in the s-video image. I was racking my head around this until I happen to pull the composite out while testing and suddenly the thin bars went away and the s-video clarity came through! Normally this wouldn't be an issue for people as they aren't that likely to have both plugged in at once but I do it for testing and on most other AV mods, this isn't an issue so I didn't think about it at first.

 

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22 hours ago, tane said:

Connecting the 4050 doesn't seem to make a difference, but it makes a very slight difference to have individual ground points for each one. (A further experiment with a UAV without the 4050 should be done, and to compare one to one).

 

4 hours ago, MacRorie said:

The 4050 left in place (by whatever means you see fit) does not degrade the quality of the output, per se.  However, additional cables simulataneously being attached does, in some cases, result in degraded signals.  IN the case of the 5200, it is essential on some boards, so this is not a universal statement across all machines.

 

A new experiment was done, and there are differences in a UAV with or without the 4050:

  • System: 65XE, NTSC, no RF modulator. CRT TV.
  • Experiment: solder the 4050 to the UAV but leave both top-right pins lifted (both are ground), no difference is noticeable. But, with those both pins connected, then connect and disconnect them to the ground:
  1. First very noticeable: the screen moves to the left half pixel.
  2. With the ground disconnected to the 4050 (the same as the UAV without the 4050), both colors 34 and 44 look almost the same (red-orange). But with the pins connected to the ground, the color 44 looks more purple and now it's noticeable with the color 34.
  3. Some dark colors (column 0) are now brighter, and some bright colors are now darker (column C). The benefit of this is that the C colors, now aren't seen with a distortion crown around them over a dark background. One pixel and small shapes are better defined.
  4. It's likely there are cons depending on displays and machine. A switch is likely to be added. Is there an study/comparison about the 4050?

 

Edited by tane
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17 minutes ago, tane said:

Is there an study/comparison about the 4050?

What do you mean by that? The 4050 is merely a standard buffer chip. It adds a small signal delay and isolates the outputs of the LUM and SYNC signals from direct connection to the rest of the output circuitry. 

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I mean that the presence of the 4050 makes some slight color changes to a 65XE, and maybe somebody else has studies this before (meaning I'm asking for such results).

 

Another experiment but with an 800XL, NTSC, no RF:

One ground pin of the 4050 connected to the ground (don't remember which one) makes an overall brighter image, and the other pin makes it darker. Both together make a brighter image, but I don't see any color changes. It doesn't seem to be an interesting change as it was with the 65XE.

 

Edited by tane
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@tane

 

The pixel shift and color changes.... did you try the jumper to change the artifacting to see if that changes your observations ?

 

IIRC I changed it from the default on my 600XL to get the artifacting I wanted (and what I think matched what I observed before the upgrade, but that's stressing my memory ? )

 

 

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3 hours ago, cwilbar said:

The pixel shift and color changes.... did you try the jumper to change the artifacting to see if that changes your observations ?

That should be highlighted somewhere, a lot of improvement for a 65XE.

 

My experiment with the 4050 makes a different effect, still interesting for a XE.

 

Also regarding colors, I realized that different brands of GTIA output different color palettes even for the same machine.

 

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  • 4 weeks later...

I recently installed a rev. D board in my 2800 to replace a failed 2600RGB board. The composite and s-video output are excellent and come very close to the output of the 2600RGB board.

 

My 2800 revision has the color saturation resistor installed, so I needed to lift pin 6 of the TIA.

 

Without the pin lifted, my monitor would not display any green hues. Everything appeared blue.

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