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Sophia rev.C - DVI board

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I didnt like how the pixels Sophi outputs are square. On NTSC the pixels are not square so the images from the DVI output of Sophia dont match what the analog output looks like.

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That also depends on how your monitor scales the sophia output to its panel resolution. You might experiment with some zoom modes if your monitor or tv has these. I would imagine using the sophia output, regardless what the sophia resolution is, should be watched in or scaled to a 4:3 aspect ratio, so it has black bars on the left and right when watched on a modern 16:9 or 16:10 panel.

Edited by jowi
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I had Sophia on a 4:3 monitor, no scaling, 1280x1024. Simius confirmed he chose not to emulate NTSC pixels and to display them as square. I ended up putting the non-DVI Sophia in instead.

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I’m fine with Square pixels. I don’t have any nostalgia for any particular shape. I just need as clean and clear as an image as possible .

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I'm not sure what you mean with "square NTSC pixels", and that being a problem; Maybe post a screenshot?

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NTSC has fewer scan lines overall and the analogue NTSC signal tends to be rendered with everything looking 'taller' in order to fill the screen (and with narrower top and bottom borders). The issue with entirely digital solutions failing to emulate such behaviour is to be expected but is not to everyone's taste.

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I had Sophia on a 4:3 monitor, no scaling, 1280x1024. Simius confirmed he chose not to emulate NTSC pixels and to display them as square. I ended up putting the non-DVI Sophia in instead.

AFAIK, all 1280x1024 monitors are 5:4, not 4:3. If they were, they would have to have non-rectangle pixels.

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AFAIK, all 1280x1024 monitors are 5:4, not 4:3. If they were, they would have to have non-rectangle pixels.

I think you are right but the manufacturer could also have increased the vertical pixel spacing (or lowered the horizontal spacing) to create a 4:3 aspect ratio.

Edited by jowi
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Received my Sophia rev C board this week for my 800xl. Works amazingly well but now trying to figure out how I can fit it whilst still being able to fit the metal shielding to the inside of my 800xl. Has anybody been able to re-fit the metal shielding... perhaps by 'modifying' (cutting into and bending) the metal shielding to provide clearance over the Sophia board? If so I'd be very interested to see photos.

 

I understand the metal shielding is there to avoid electrical interference from other electrical devices. Do I really need to be worried about electrical interference without my metal shielding... or are there usually no adverse effects of running an 800xl without metal shielding...?

 

Next I need to mount the Sophia DVI port to the back of my 800xl. Has anybody done this successfully...? I've seen one person's photo of how this was done from the outside of the case... but photo's from the inside of the case would be far more interesting. On an 800xl, is it recommended to remove the TV modulator and mount there...? If so how is the TV modulator removed and what method/tools are used to mount the DVI port...?

 

Many thanks,

Graham.

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Thanks for the link jowi. I figured out a way of creating more space for the shielding and case closure on my 800xl by removing the ic mount of the Dm74LS158N ic that's just above the GTIA.

 

Now, I have removed the TV modulator and plan on fitting the DVI connector in its place. However, there doesn't seem to be any detailed info on this thread as to exactly how the DVI connector can be firmly mounted to the back plastic case of the 800xl.

 

Does anybody have any advice on how best the actual DVI connector can be firmly mounted on the back of the plastic case of the 800xl...?

 

Thanks.

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The 'dispute' i'm having with Simius is that he states that there is nothing wrong with the Sophia signal and all issues are monitor related, my point is that there is a timing issue with the signal, since some monitors and tv's accept it, but most wont. Now, since Simius is not inclined to make any changes on his side, we have to find a solution.

 

A similar dispute you could have with the Atari company. Because their computers can't be connected to all TVs and monitors everywhere. Would you been surprised if they states that there is nothing wrong with the Atari signal and all issues are monitor related? :)

Your problem is the wrong belief that the solution is a simple change the front/back porch or something like that. What I don't want to do myself and I don't want to let you. Why would I don't want if it is so simple? The matter is more complicated that you think and requires more resources (memory, PLLs, logic elements) than are available on the current hardware. My english is too weak to explain it more detailed. This should be enough.

I would like Sophia to work with all monitors and TVs everywhere, but it must be enough that it works with most monitors in NTSC computers, with a part of monitors in PAL machines and even with some TVs (especially 4K TV).

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Does anybody have any advice on how best the actual DVI connector can be firmly mounted on the back of the plastic case of the 800xl...?

 

The board with DVI connector is intended to mount on the MB using the holes remaining after the disassembled modulator. Not on the plastic case.

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Okay,thanks Simius... but how exactly is the DVI board 'secured' firmly to the motherboard?

 

The DVI board has no screw holes in it to match the holes that were left by the TV modulator. So do I need to drill some holes in the DVI board to enable me to screw it to the motherboard... or do I use a strong glue to bond the two boards together perhaps...?

 

Thanks.

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The dvi connector is mounted to the metal shield, not the plastic, again, see my pictures. The metal shield, once in place, is strong enough.

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Okay,thanks Simius... but how exactly is the DVI board 'secured' firmly to the motherboard?

 

The DVI board has no screw holes in it to match the holes that were left by the TV modulator. So do I need to drill some holes in the DVI board to enable me to screw it to the motherboard... or do I use a strong glue to bond the two boards together perhaps...?

 

Thanks.

No drill, no glue. Just a soldering iron and a 3-pin (XL) or 2-pin (XE) 0.100" male headers like that:

 

793_t.jpg

 

794_t.jpg

Edited by Simius
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No drill, no glue. Just a soldering iron and a 3-pin (XL) or 2-pin (XE) 0.100" male headers like that:

Yeah that makes totally sense if you buy this board (not!)... Why did you not show us this before? Why was this never mentioned by anyone? Any more surprises?

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I have shown. Look at the first post in this thread. I thought it is obvious. What these small holes are for at the edge of the board?

My fault is that I didn't add these headers to the package. I will be adding.

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Now i know how you intended to mount it, i can see it in the picture, but i have never noticed it before, and it was never mentioned, also not by others. I don't think anyone has ever spotted this.

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I have shown. Look at the first post in this thread. I thought it is obvious. What these small holes are for at the edge of the board?

My fault is that I didn't add these headers to the package. I will be adding.

It was obvious to me mate.

 

Sent from my SM-G900F using Tapatalk

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Hi,

 

I´ve built the Sophia DVI into an Atari 5200 console and it works fine. But what I missed: The Audio output. The 5200 shall be connected to a standard 40" TV with HDMI only. Video works fine with a DVI to HDMI cable of 3 meters. Now I look for a nice option to integrate the Audio of the 5200 console into the HDMI video stream. My 1st wish was to include this into the 5200, there´s enough space. Does anybody here have a suggestion for a small DVI & analogue Audio to HDMI converter? I saw the Monoprice item at the beginning of this thread, but this device is not really small.

 

Any hints welcome.

 

Jurgen

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Hi,

 

I´ve built the Sophia DVI into an Atari 5200 console and it works fine. But what I missed: The Audio output. The 5200 shall be connected to a standard 40" TV with HDMI only. Video works fine with a DVI to HDMI cable of 3 meters. Now I look for a nice option to integrate the Audio of the 5200 console into the HDMI video stream. My 1st wish was to include this into the 5200, there´s enough space. Does anybody here have a suggestion for a small DVI & analogue Audio to HDMI converter? I saw the Monoprice item at the beginning of this thread, but this device is not really small.

 

Any hints welcome.

 

Jurgen

Another option is to use a DVI-D to HDMI cable that also carries the analog audio signal.

https://www.mycablemart.com/store/cart.php?m=product_detail&p=6237

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This is a big problem as well. I dont know of any tvs, monitors or even receivers that allow you to use a (digital) hdmi videosignal, and discarding its (non-existing) audiopart, and combine it with an analog audio input... i dont even think a scaler will allow this, not sure, maybe a professional one.

 

If you are using a pc monitor and dont have the need to route the atari through your home/multimedia devices, the only thing you can do is add some external speakers with built in amps and analog input. Like the video in the start topic of this thread. Or, if your tv has multiple hdmi inputs, use that for picture and use an analog input on the receiver (same principle). Probably the only solution for me as well... my receiver is the hub for all signals, but not for this one.

 

Or find some (pro) mixing device that has hdmi in and out that allows to convert and mix the audio into the hdmi output...

Edited by jowi

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