The UAV Rev. D Video Upgrade Thread

[rmzalbar]

On 5/16/2020 at 3:51 PM, rmzalbar said:

Is there something non-standard about the way the Atari 2600 syncs? After installing the UAV mod and using the composite output:

 

 - My CRT television shows a "flag-waving" horizontal distortion effect in the top 10% of the screen with bright playfields

 - Most of my CRT monitors lose sync for a frame or two on bright color flashes

 - Two of my monitors, both JVC A13SU, fail to sync vertically at all with the 2600 (rapidly rolling picture.)

 

These things don't occur with the RF output. This is on a four-switch 2600, all five lines taken from the TIA socket. Any ideas?

 

WELL. I figured this out. Mine is a 4-switch with no 4050 so I manually wired it. I had 3 wires swapped around, 2 luma and 1 sync! I don't know how I made a mistake like that, or why I didn't find it quickly. I must have been looking at an erroneous pinout or something of the sort back then, and I evidently didn't look at the signals live, but sure enough when I put the oscilloscope on the sync input I saw a luma pattern. D'oh!!

 

The luma and sync are TTL signals that then go through different voltage dividers (on the Atari on the way to the modulator, but also on the UAV board in a similar way) to set their relative levels, so that 3 separate TTL luma signals can be mixed in binary fashion to make several luma levels and you get a proper sync level. They were going through the wrong resistor networks so they were at the wrong levels! The sync pulse was too small, causing unstable sync. On bright screens or games that flash the screen brightly, it would lose sync altogether.

Edited January 26, 2022 by rmzalbar

[iscariot]

Hey guys, I think I got this installed right, but I downloaded the UAV_XEX.xex and put it on my AVG cart but it won't start.  It just gives me a black screen.  Is there another one that I need to download or something?  If not, what about another tool to test with?

[_The Doctor__]

if it doesn't work directly from the AVG loader, use the AVG to call the sideloader and try loading from there. this method works well as there are things the avg loader will load and there are things the sideloader will load but not vice versa..... else put it on an ATR disk or Partition with appropriate DOS etc... and launch it that way

[Lakz]

I've been eyeing the UAV to upgrade the video on my 800XL and had a question. Would it be possible to use the composite output from the UAV to improve/maintain RF output? If not, is there a way to keep RF output when installing UAV into a 800XL?

 

 

Any tips would be appreciated, thanks.

 

(Also first post, yay!)

[hueyjones70]

On 7/3/2022 at 9:55 PM, Lakz said:

I've been eyeing the UAV to upgrade the video on my 800XL and had a question. Would it be possible to use the composite output from the UAV to improve/maintain RF output? If not, is there a way to keep RF output when installing UAV into a 800XL?

 

 

Any tips would be appreciated, thanks.

 

(Also first post, yay!)

You can solder the UAV on top of the 4050 chip and that will maintain UAV output. However, I can't imagine why you would want to use RF if there was any other option.

[Beeblebrox]

Exactly - RF is really a last resort.

 

 

[+x=usr(1536)]

1 hour ago, Beeblebrox said:

Exactly - RF is really a last resort.

In terms of picture quality, absolutely.  For troubleshooting, though, it's incredibly useful.

[Beeblebrox]

3 minutes ago, x=usr(1536) said:

In terms of picture quality, absolutely.  For troubleshooting, though, it's incredibly useful.

true. 

[+-^CrossBow^-]

3 hours ago, hueyjones70 said:

You can solder the UAV on top of the 4050 chip and that will maintain UAV output. However, I can't imagine why you would want to use RF if there was any other option.

That is exactly what I did with the last 800xl I put a UAV into for someone. Although I also removed the composite line on the monitor port and replaced it with the composite output from the UAV in addition to the s-video signals. But leaving the 4050 in circuit is how you keep the RF working. It is the same for the 5200 as well of course.

 

[Dopy25]

1 hour ago, -^CrossBow^- said:

 I also removed the composite line on the monitor port and replaced it with the composite output from the UAV in addition to the s-video signals. 

What are the advantages of doing this? I only have the svideo signal going to the video out port but am wondering if there is a big difference in where the signal comes from. I have noticed the stock composite is darker than the svideo. Would it change it so they would be closer in colors?

[Lakz]

5 hours ago, hueyjones70 said:

You can solder the UAV on top of the 4050 chip and that will maintain UAV output. However, I can't imagine why you would want to use RF if there was any other option.

I only have a small RF tv, so I’m stuck with it for now.
But thanks for the tips! 

[+-^CrossBow^-]

1 hour ago, Dopy25 said:

What are the advantages of doing this? I only have the svideo signal going to the video out port but am wondering if there is a big difference in where the signal comes from. I have noticed the stock composite is darker than the svideo. Would it change it so they would be closer in colors?

I did that because IMO the UAV provides a better quality composite output in most instances in addition to the s-video.

[hueyjones70]

The UAV manual instructs the user to replace the computer composite with the UAV composite. See post 96 of this thread.

[+mytek]

Yeah if you are going to install a UAV, why wouldn't you want to send all the video outputs to the DIN-5 jack instead of the crappy original ones?

 

This is usually quite easy to do, especially concerning the composite output which is wired to the A/V jack on all the 8-Bit line. It's simply a matter of cutting a ferrite bead jumper that sends the original signal out to the jack, and then wiring a jumper from the UAV composite output to this same spot. This is probably also documented in the UAV manual or a previous post as was pointed out.

 

I believe on an 800XL it's bead L7 that needs to be cut for composite. And on a 1200XL it would be bead L3. As for the other systems you'd have to check out the schematics.

 

[hueyjones70]

Can anyone tell me where the UAV connections are made on an 800XL PAL with the FREDDIE chip. I know that I could cut traces and wire directly to the DIN connections but I hate to do it that way. The standard connections are not present, at least not in the same places and Chroma is connected.

[rmzalbar]

Has anyone ever tried just picking off UAV video and sending it to the RF modulator? Doesn't that work? Rather than leaving the 4050 in.

Edited September 21, 2022 by rmzalbar

[hueyjones70]

On 9/20/2022 at 7:58 PM, hueyjones70 said:

Can anyone tell me where the UAV connections are made on an 800XL PAL with the FREDDIE chip. I know that I could cut traces and wire directly to the DIN connections but I hate to do it that way. The standard connections are not present, at least not in the same places and Chroma is connected.

I thought I had it figured out; I determined by T&E that color in can come from the top of the left-most resistor in the row just below the 4050 chip.  I got composite, I lifted the left end of a ferrite bead (FB1 I think) and connected Composite to the vacant spot.  Another ferrite bead (FB2) appeared to connect to Luma but when I connected it I completed the S-Video connection. Something is amiss and I might just go ahead and cut some traces.  I don't have a schematic and it is difficult to follow traces that jump from one side of the board to the other and are also blocked by ICs, resistors, etc.

[rmzalbar]

2 hours ago, hueyjones70 said:

I thought I had it figured out; I determined by T&E that color in can come from the top of the left-most resistor in the row just below the 4050 chip.  I got composite, I lifted the left end of a ferrite bead (FB1 I think) and connected Composite to the vacant spot.  Another ferrite bead (FB2) appeared to connect to Luma but when I connected it I completed the S-Video connection. Something is amiss and I might just go ahead and cut some traces.  I don't have a schematic and it is difficult to follow traces that jump from one side of the board to the other and are also blocked by ICs, resistors, etc.

Schematic is here, it's a Jerzy Sobola one so very clear to read but may have some errors and this one looks a little bit incomplete in the composite mixing area. But compare it to the 800XL one and you should determine which components to lift so you don't have to cut.

800XLF (Freddie):

https://systemembedded.eu/viewtopic.php?t=39

 

800XL:

https://systemembedded.eu/viewtopic.php?t=38

 

[hueyjones70]

I found the Sobola schematic but I couldn't see a path to Chroma.

[hueyjones70]

3 hours ago, hueyjones70 said:

I found the Sobola schematic but I couldn't see a path to Chroma.

I held the MB up to a very bright light and I was able to trace the Chroma circuit to FB3. All of the video connection points are ferrite beads just to the left of the RF box. FB1 is Luma, FB2 is Composite, and FB3 is Chroma.

[pseudografx]

Just wanted to share a couple of comparison screenshots I made today with and without UAV. The left one is my UAV-equipped 800XE, the right one is stock, unmodified 130XE. Both PAL.

Screenshots taken using my RetroTink 2x Mini and ezCap 321a USB HDMI grabber.

 

Edited October 7, 2022 by pseudografx

[+slx]

TBH the only differences I can spot from here are the vertical lines in the test pattern an a few more ragged edges in the "shadow" under the Bunny Hop title. You must have a good 130XE to start with.

 

[pseudografx]

Also the white/bright areas are not as bright on the stock machine and jailbars are slightly visible in some uniform areas.

[+-^CrossBow^-]

Anyone know if Bryan's UAV.xex artifact test program was ever ported to the 5200? I'm thinking it was but cannot find a copy of such a file. It would be nice to have to dial that in on 5200 UAV installs.

 

[flashjazzcat]

Can anyone point me to the jumper settings for the Rev. C boards? My Google-fu has so far failed me for once.