New video upgrade coming soon!

[Bryan]

Hello Bryan

 

If the configuration jumpers are the two rows of ten pins each then yes, that's what I was asking.

 

Sincerely

 

Mathy

 

Removing the configuration jumper pins would be difficult. It would be better to order one without those things installed and just put your own wires on it. Are you trying to make it thinner/smaller?

 

-Bry

[+pboland]

 

Hope this helps. However, remember this is still a prototype.

Wow! that S-video of your upgrade looks great!

 

Now I'm really interested. What's the price for this upgrade?

[Bryan]

Wow! that S-video of your upgrade looks great!

 

Now I'm really interested. What's the price for this upgrade?

Thanks. I'm still working out the price. When I get everything finalized I'll let you know.

[kenjennings]

Depending on price I'd probably get two, three, maybe four.

[+orpheuswaking]

If it fits the 400 I'll be down for a couple. I've been trying to get good video from a couple of my machines for awhile.

[FifthPlayer]

Take my money. I want one when they're available.

Edited December 12, 2015 by FifthPlayer

[Bryan]

Taking pictures from my monitor (JVC TM-A13SU) has made me realize it has a non-defeatable comb filter in Composite mode. Maybe my next project will be a monitor hack to intercept the I2C commands to the video processor to defeat it once and for all!!

 

** comb filters cause weird effects between different colored adjacent lines. The comb filter is designed for camera video, not computer video.

[adam242]

*never mind, read a little more.. Deleted*

Edited December 12, 2015 by adam242

[SwampFox56]

Excellent! Can't wait to get my hands on one!

[flashjazzcat]

Could this not be made to plug into the CD4050 socket, and have the CD4050 optionally plugged into a socket on the daughterboard?

[Bryan]

Could this not be made to plug into the CD4050 socket, and have the CD4050 optionally plugged into a socket on the daughterboard?

 

Hmm.. Anything I add at this point makes the upgrade bigger. It was never my intention to leave the onboard video working as a feature of this device, only as an installation option. If you want to leave the existing video alone and are limited on space, I'd recommend getting the version without the socket header and mounting it elsewhere.

 

If I come up with something else I'll let you know.

[morelenmir]

How does this compare with the VBXE? Is it worth swapping one out for this mod instead?

[Bryan]

How does this compare with the VBXE? Is it worth swapping one out for this mod instead?

This is a video quality enhancer which provides improved Composite and S-Video signals (the same signals available on most A8's) with an emphasis on noise removal.

 

It does not add new video modes or features like VBXE. Because GTIA is designed for generating standard-definition analog TV video, it's difficult to offer other video formats without a lot of circuitry. VBXE does it by implementing the entire GTIA in an FPGA.

 

-Bry

[morelenmir]

This is a video quality enhancer which provides improved Composite and S-Video signals (the same signals available on most A8's) with an emphasis on noise removal.

 

It does not add new video modes or features like VBXE. Because GTIA is designed for generating standard-definition analog TV video, it's difficult to offer other video formats without a lot of circuitry. VBXE does it by implementing the entire GTIA in an FPGA.

 

-Bry

Many thanks Bryan, I think I understand this device a little better now.

[iesposta]

Great job! Brilliant idea!

All the discussion of systems that have beautiful Composuite out (like the NES) proves that method can be done right.

Finally someone smart like you has a simple solution to correct all the mistakes and cost cutting degradation.

Looking forward to this.

 

I made an S-Video off the 4050 in the Atari Jr., but I'm just not satisfied enough with the results to finalize that project.

 

P.S. If you could adapt this to the Intellivision you would sell a lot! Nothing I have tried there as been better than RF (except in convenience of hookup). There is always something not right about the composite Intellivision mods.

 

The original 1977, 1978 Atari VCS, either by design or dumb luck, has beautiful RF output.

It seems that cost cutting and redesign made output worse and worse with each passing year, with a few exceptions such as some Atari 2600 Jr.'s have nice RF output.

 

That being said, Composite and S-Video are a big step up for any machine beyond a'77 '78 Atari 2600 Heavy Sixer.

 

Also artifacting in the Atari computers was used in game design, and is the way I remember the system, in a similar way the RF smoothing/blurring in the Atari 2600 improved the overall blocky display.

This is a video quality enhancer which provides improved Composite and S-Video signals (the same signals available on most A8's) with an emphasis on noise removal.

 

It does not add new video modes or features like VBXE. Because GTIA is designed for generating standard-definition analog TV video, it's difficult to offer other video formats without a lot of circuitry. VBXE does it by implementing the entire GTIA in an FPGA.

 

-Bry

[Bryan]

Great job! Brilliant idea!

All the discussion of systems that have beautiful Composuite out (like the NES) proves that method can be done right.

Finally someone smart like you has a simple solution to correct all the mistakes and cost cutting degradation.

Looking forward to this.

 

Thanks. It's something I've tinkered with and wanted for a long time. Only recently did I begin to analyze it detail. One interesting thing is that the 4 LUM lines don't all change at the same time (skew). This varies from GTIA to GTIA, but it can cause a real loss of definition in the picture. I address this by re-clocking the luminance which brings the edges in line and also provides the artifact color adjustment by letting you change the alignment delay.

 

I made an S-Video off the 4050 in the Atari Jr., but I'm just not satisfied enough with the results to finalize that project.

 

It's interesting that the TIA has TTL outputs for LUM so it doesn't necessarily need the 4050 (and many 2600's don't have it), but the 4050 has much better drive capability and makes a better DAC. I'm using HC parts for an even better spec but without the re-clocking the standard CMOS parts are actually better for hiding the skew. GTIA has open collector LUM outputs.

 

P.S. If you could adapt this to the Intellivision you would sell a lot! Nothing I have tried there as been better than RF (except in convenience of hookup). There is always something not right about the composite Intellivision mods.

 

I'll have to look at how the Intellivision works. Maybe this could be adapted (looks like it uses an AY-3-8915 for video).

 

The original 1977, 1978 Atari VCS, either by design or dumb luck, has beautiful RF output.

It seems that cost cutting and redesign made output worse and worse with each passing year, with a few exceptions such as some Atari 2600 Jr.'s have nice RF output.

 

I agree. Atari put a lot of work into the original design.

 

That being said, Composite and S-Video are a big step up for any machine beyond a'77 '78 Atari 2600 Heavy Sixer.

 

Also artifacting in the Atari computers was used in game design, and is the way I remember the system, in a similar way the RF smoothing/blurring in the Atari 2600 improved the overall blocky display.

 

Yep. Artifacting was especially popular with Apple II ports and gave a very similar look. GTIA should have had a register to change the colorburst phase and then we'd have a lot more flexibility with artifacting.

 

-Bry

[KLund1]

Can't wait to get a few of these!!!!!, if the price is right.

 

But I'm not quite as technical as some others here that have asked questions, but I can solder ok, and find and pull chips.

 

Let me see if I understand how this great new unit works:

 

 

Replaces curent video output

 

I need to figure out what output to use composite, or chrome/luma, and then build a jack from this unit to it, or use the DIN on the MB

 

I need to remove the 4050 IC, install a sockit in it's place, unless it is already socketed. And add a wire to the GTIA in some machines. What about CTIA's.

 

I could leave the 4050 in and place the new unit on top with a socket soldered on top of the 4050. This so I can have the old outout, and the new output with a 2nd jack somewhere.

 

Souds like it will work with VBXE, but someone need to test it first. What about the other popular upgrades (SuperVideo 2.1, etc)

 

There might be grounding issues with some machines. How could I tell it I have such a machine.

 

Will there will be some docs and diagrams on how to hook this up. Where each connection on the green output block would go to and existing DIN or a new connection for S-Video, or composite. and for each type of machine, etc.

 

Again this looks like a REALLY Good upgrade!!!!

I wish you all the success you will get from this!!!!

[adam242]

1200XL

Yes. It'll be very close to the back shield. It might be best to cut a hole in the shield or turn the green terminal around facing in. Hmm... Can someone take a measurement from the center of the 4050 socket to the shield?

 

http://atariage.com/forums/uploads/monthly_09_2012/post-19239-0-69953700-1347735211.jpg

 

There's 26-27mm from the centerline of the 4050 socket to the edge of the ground plane for the shield.

 

(parallax error in that first photo, the 10mm mark was on the edge of the shield ground:

[Bryan]

 

There's 26-27mm from the centerline of the 4050 socket to the edge of the ground plane for the shield.

 

Thanks!! It's about 23mm on the current board and I imagine that the shield actually sits 1-2mm back from the edge of the ground plane. By any chance can you post a picture of the distance from the shield mounting hole to the 90-deg bend at that point?

 

I'll try to see if I can shave a mm or two on the next rev.

[Bryan]

Can't wait to get a few of these!!!!!, if the price is right.

 

But I'm not quite as technical as some others here that have asked questions, but I can solder ok, and find and pull chips.

 

Let me see if I understand how this great new unit works:

 

 

Replaces curent video output

 

The typical installation would be to replace the built-in video, yes.

 

I need to figure out what output to use composite, or chrome/luma, and then build a jack from this unit to it, or use the DIN on the MB

 

Or use both! You only get artifact colors with composite, but chroma/luma looks better.

 

I need to remove the 4050 IC, install a sockit in it's place, unless it is already socketed. And add a wire to the GTIA in some machines. What about CTIA's.

 

I could leave the 4050 in and place the new unit on top with a socket soldered on top of the 4050. This so I can have the old outout, and the new output with a 2nd jack somewhere.

 

You can do whatever you have room to do. The 4050 needs to be there for on-board video to work. The lowest profile options would be:

 

a. Install a zero-profile socket in the motherboard and solder the 4050 directly to the UAV (no socket). Then plug the 4050 back in with the UAV attached.

 

b. buy the version without the header and run wires to it.

 

c. forget onboard video and just plug it into a socket.

 

Souds like it will work with VBXE, but someone need to test it first. What about the other popular upgrades (SuperVideo 2.1, etc)

 

If you have room for both, then I guess it would. It will only affect the output of the GITA, though.

 

Other board-level video upgrades will continue to work with the onboard video if the 4050 is installed. UAV is a parallel system and is unaffected by most modifications to the board.

 

There might be grounding issues with some machines. How could I tell it I have such a machine.

 

The power to the 4050 socket can be an insurmountable problem on some boards. If you have any issues with the picture just run new power and/or ground wires to the UAV. Ground can be attached from the terminal strip to the back of the motherboard. 5V must be soldered to the large pad in front.

 

 

Will there will be some docs and diagrams on how to hook this up. Where each connection on the green output block would go to and existing DIN or a new connection for S-Video, or composite. and for each type of machine, etc.

 

Yes. I'll try to get pictures of each machine and I'll describe the options fully.

 

Again this looks like a REALLY Good upgrade!!!!

I wish you all the success you will get from this!!!!

 

Thank you!

 

-Bry

[Mathy]

Hello Bryan

 

Are you trying to make it thinner/smaller?

 

 

Yes. And less ugly. (Sorry!) It seems like PCB's that are made to be installed inside the computer often come with (relatively) big connectors. At least the last couple of years. I like small things (when it comes to the Atari 8 bit computer).

 

Sincerely

 

Mathy

[Bryan]

Hello Bryan

 

 

Yes. And less ugly. (Sorry!) It seems like PCB's that are made to be installed inside the computer often come with (relatively) big connectors. At least the last couple of years. I like small things (when it comes to the Atari 8 bit computer).

 

Sincerely

 

Mathy

 

Well, I was trying to make most of the connections solderless, and you can't get a much smaller screw terminal than the one I'm using. But I know what you mean.

[flashjazzcat]

That XEGS comparison shot shows a really marked improvement. Y/C looks excellent.

[Bryan]

That XEGS comparison shot shows a really marked improvement. Y/C looks excellent.

Thanks.

 

There's three main things that affect the way A8 video looks:

 

1. Luminance levels (gain): Different models are inconsistent in what voltage comes out for a LUM of 0 vs. 15. Stronger luminance gives a brighter but more washed picture out since a stronger chroma carrier is required as well. In other words, for a given saturation of color an NTSC or PAL monitor requires more chroma amplitude as the luma amplitude rises. The A8 only produces one chroma amplitude so bright colors will never be very saturated without external manipulation of the chroma.** Even if you boost the chroma level the monitor will simply adjust the color level back down because it calibrates each line based on the level and phase of the colorburst. In summary, you get better color if you don't go for the brightest picture possible. I'm basing UAV's levels on a average across the A8 line.

 

2. Composite mix levels: One interesting thing about composite video is that even though a stronger chroma carrier doesn't boost the saturation (because the monitor auto detects the colorburst level), the stronger chroma does affect the purity of the image. A weak carrier requires that the carrier filter output be boosted which means any luma crosstalk information that leaks in gets boosted too. This means you can see more color errors on edges and text as you turn the chroma level down. Inversely, if you boost the level, everything gets cleaner and starts to look more S-video-like because the luma crosstalk is now a smaller percentage of the signal. The only problem is that the color carrier starts to appear as a dot/narrow bar pattern in the picture because it's harder to filter out. Striking the right balance for a clean picture is important.

 

3. Bandwidth: Many of the A8 video circuits have poor luminance bandwidth and text looks soft and "thin". High resolution (320) pixels have a clock rate of 7MHz (generated by GTIA using both edges of the 3.58Mhz clock) and a slow luma response time gives you the look of the first XEGS picture with thinner, less defined text ..and the XEGS is one of the better stock machines.*** The UAV pictures show you video with more than twice the bandwidth required to display A8 video.

 

 

** The 1200XL attempted this with a squelch circuit for the colorburst, but it caused dark colors to be oversaturated and bleed.

 

*** The Atari method of mixing chroma and luma cuts the bandwidth of the composite signal down significantly, even if the luminance signal is nice and sharp.

[adam242]

 

Thanks!! It's about 23mm on the current board and I imagine that the shield actually sits 1-2mm back from the edge of the ground plane. By any chance can you post a picture of the distance from the shield mounting hole to the 90-deg bend at that point?

 

I'll try to see if I can shave a mm or two on the next rev.

 

 

If I understand you correctly, that distance from the center of the hole to the 90-deg corner is 45mm. This is the area directly above (behind?) the 4050...

 

(parallax again, the corner was aligned with the 20cm mark on the ruler)