TV systems converter via graphics card

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TV systems converter via graphics card

Postby Harry Dalek » Fri Mar 09, 2018 12:02 am

I found this really interesting ....seems simple even for me ,apart from needing a graphics card in your PC that has 2 VGA sockets ,i wonder if a laptop the monitor screen counts as one and the vga socket the other would be the same idea ? checking testing the the program it detects my graphics chip .
http://www.nostalgiatech.co.uk/Baird%20240%20lines.htm

Another forum chatting about this
https://www.vintage-radio.net/forum/sho ... p?t=144356


youtu.be/ahzdx4KgWBg
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The electromagnetic spectrum has no theoretical limit at either end. If all the mass/energy in the Universe is considered a 'limit', then that would be the only real theoretical limit to the maximum frequency attainable.
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Re: TV systems converter via graphics card

Postby Harry Dalek » Sat Mar 10, 2018 9:55 pm

I wanted to see if my idea of the extra screen on the laptop would pretty much copy the results of the desk top with the dual VGA card plugs ....and doing it on the cheap just using what i have .
Testing mode line program it detected the video chip in 2 out of 3 of my laptops so gave one of those a go.
So i made the circuit ,adjusting the video settings so i had extended screen across to the VGA monitor plugged into the laptop ,adjusting mode line for 625 line .
Now the problem here is soon as you disconnect the monitor plugged into the laptops VGA socket it switches off the video signals and reverts back to pre dual laptop settings .
Now that was a pain !
I needed to leave that monitor plugged in and also out put the video out of the VGA socket ...so ended up splicing an old VGA cable to access the video and sync .
Now this sort of works a quick hook up to one of the colour channels i have video ! getting 2 pictures bit of tearing top of the picture may be i should reduce the vertical to 25 hz first results i am happy ....
Pictures first the simple circuit in the last post combining correct levels of red green and blue and the sync ..because every time i tried to plug this in the VGA signals would cut out so it was useless so far .
Next 2 pictures ugly quick VGA cable splice it kept the monitor on and accessing the video and sync .
last 2 just a quick hook up to an old 625 line Security Camera monitor ..first results .
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The electromagnetic spectrum has no theoretical limit at either end. If all the mass/energy in the Universe is considered a 'limit', then that would be the only real theoretical limit to the maximum frequency attainable.
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Re: TV systems converter via graphics card

Postby Harry Dalek » Sun Mar 11, 2018 5:19 pm

Experimenting today adding the horizontal sync pulse that helped the image could not notice a vertical sync pulse via my cable so have to look into that i was also unable so far to change the line rate and such on the mode line program only the on screen resolution changes i can see using it , the screen horizontal looks to be running at double line frequency 2 images.
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The electromagnetic spectrum has no theoretical limit at either end. If all the mass/energy in the Universe is considered a 'limit', then that would be the only real theoretical limit to the maximum frequency attainable.
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Re: TV systems converter via graphics card

Postby Robonz » Sun Mar 11, 2018 9:35 pm

That's interesting Harry, these links might help a little

A VGA dummy plug is a simple hack to fool the GPU and Windows by let them thinking there is a monitor plugged on a card.
http://www.geeks3d.com/20091230/vga-hac ... ummy-plug/

http://www.epanorama.net/newepa/2016/02 ... vga-hacks/

Cheers
Keith
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Re: TV systems converter via graphics card

Postby Harry Dalek » Sun Mar 11, 2018 9:45 pm

Robonz wrote:That's interesting Harry, these links might help a little

A VGA dummy plug is a simple hack to fool the GPU and Windows by let them thinking there is a monitor plugged on a card.
http://www.geeks3d.com/20091230/vga-hac ... ummy-plug/

http://www.epanorama.net/newepa/2016/02 ... vga-hacks/

Cheers
Keith


Thanks Keith for the links i will look after posting this ! don't know if i am barking up the wrong tree but having an image of some sort is hopeful ...i need to be able to change the line rate via mode line program if the graphics card Cooperate's or not is another matter ..if any thing i now know how to MacGyver a crt PC monitor if there's an apocalypse :lol:
The electromagnetic spectrum has no theoretical limit at either end. If all the mass/energy in the Universe is considered a 'limit', then that would be the only real theoretical limit to the maximum frequency attainable.
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Re: TV systems converter via graphics card

Postby Harry Dalek » Sun Mar 11, 2018 10:02 pm

Thanks Keith had a look the resistor dummy load might just work doing away with an extra monitor as you can i think use or do modeline on either monitor so if you set windows display to duplicate display for the monitors one and two it should work ...
I will look into it ...
The electromagnetic spectrum has no theoretical limit at either end. If all the mass/energy in the Universe is considered a 'limit', then that would be the only real theoretical limit to the maximum frequency attainable.
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useful links

Postby Harry Dalek » Tue Mar 13, 2018 7:48 pm

The electromagnetic spectrum has no theoretical limit at either end. If all the mass/energy in the Universe is considered a 'limit', then that would be the only real theoretical limit to the maximum frequency attainable.
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Harry Dalek
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Re: TV systems converter via graphics card

Postby Harry Dalek » Fri Mar 16, 2018 5:49 pm

I looked into this a touch more today .
I found my spliced vga cable does not have full pin connections ,after rebuilding the circuit with 2 VGA sockets and 2 correct working VGA cables this part of the idea works fine in fact i can unplug the second monitor now and even switch off the laptop screen and view off the CRT monitor and i have vertical lock also .
Now that's where the good luck stops it seems the graphic chip in this first lap top sticks with what ever screen resolutions you choose and does not seem to work via the mode line settings for the line and frame frequencies when set for 625 line 15,625hz and 50 hz....i am getting only what settings the graphic chips does on 640 480 its 31.500 hz and either 60 hz or 75 hz no wonder its 2 images on the crt monitor.... its pretty good all i notice is a bit more flicker on 60hz it locks on 75hz as well.
I am going to try the second laptop see how that works i am not hopeful but least i know if i track down a correct graphic's card for a desktop pc it can be done.
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The electromagnetic spectrum has no theoretical limit at either end. If all the mass/energy in the Universe is considered a 'limit', then that would be the only real theoretical limit to the maximum frequency attainable.
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Harry Dalek
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Re: TV systems converter via graphics card

Postby Harry Dalek » Sun Mar 18, 2018 8:15 pm

Come to a point here where there are a few ways to go i tried my second lap top and stuck with pretty much the same settings is what it is .
If any one wants just pal B/w crt monitor signal with a divide by 2 circuit for the 31500hz to get 15750hz leave the 60hz as is for Pal M 525 line ,that's one way to go .
What i know works for a desktop a PCI slot Graphic card dual-head nVidia Quadro NVS 285 graphics adapter..good thing is its cheap too for around 30 or 40 bucks .
Could also go get a usb hub for a graphics pci card again if you only have a laptop .
I am thinking of just getting the graphics adapter in time and try this project again ,half done is where i will have to leave this for now but i will continue when i buy the card...i still like the idea of a PC tv systems converter playing around up to here i can see its doable .
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The electromagnetic spectrum has no theoretical limit at either end. If all the mass/energy in the Universe is considered a 'limit', then that would be the only real theoretical limit to the maximum frequency attainable.
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Harry Dalek
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Re: TV systems converter via graphics card

Postby Harry Dalek » Wed Mar 28, 2018 5:20 pm

Peter on another forum gave me a link to he's improved 405 line results with mode line .
http://golbornevintageradio.co.uk/forum ... 6#pid74306
see also a link to hes page on this page on the results change .
Posted up the screen shots in case any one can't view them large .
Also go to the first page on interesting read on how to do it .
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The electromagnetic spectrum has no theoretical limit at either end. If all the mass/energy in the Universe is considered a 'limit', then that would be the only real theoretical limit to the maximum frequency attainable.
User avatar
Harry Dalek
"Fester! Don't do that to 'Thing'"
 
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