GBS-8220 RGB TO VGA Converter

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Peter
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Re: GBS-8220 RGB TO VGA Converter

Postby Peter » Sat Feb 05, 2011 10:11 pm

The pole terminals. And you?

Would you please be a bit more precise about your results?
- No vertical "jumps" at all?
- Single pixels in 512x256 clearly visible?
- Which QL?


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vanpeebles
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Re: GBS-8220 RGB TO VGA Converter

Postby vanpeebles » Sat Feb 05, 2011 10:25 pm

I have it spliced into the P11 connector next to the pole terminals. Using an old scart cable with the scart end cut off. I had green, blue and red wires, h sync, v sync and ground.

http://www.youtube.com/user/QLPeet

for the videos of it in action, try clicking the 480p button as well. No vertical jumps, a very clear picture and a standard UK QL, fairly late model one.


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Peter
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Re: GBS-8220 RGB TO VGA Converter

Postby Peter » Sun Feb 06, 2011 12:14 am

Since the level converters are probably within the SCART connector, this might be the plain digital QL signals.

You say HSYNC, but neither the QL nor SCART have HSYNC. Did you use CSYNC for it?


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vanpeebles
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Re: GBS-8220 RGB TO VGA Converter

Postby vanpeebles » Sun Feb 06, 2011 12:27 am

I think I did. I based my wiring on this guide:

http://www.fruitcake.plus.com/Sinclair/ ... ableQL.htm


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Andi B.
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Re: GBS-8220 RGB TO VGA Converter

Postby Andi B. » Thu Apr 21, 2011 8:03 pm

Today my Converter arrived and I soldered the R,G,B, HSync (to Csync), VSync and ground of the attached cable directly to the QL 8 pin DIN plug. It works!

Image

Although the picture is not 100% clear and - as Peter discribes - Characters are not so good legible in 512x256, and the single pixels at the border can not be distinguished. If it also jumps I have not tested.

All in all I think I can live with it :)

BTW:
What is meant with "Since the level converters are probably within the SCART connector, this might be the plain digital QL signals." Is there something special inside SCART cables except wires?

Greetings
Andi
Last edited by Andi B. on Sat Nov 10, 2012 6:22 pm, edited 1 time in total.


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Andi B.
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vanpeebles
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Re: GBS-8220 RGB TO VGA Converter

Postby vanpeebles » Sun Apr 24, 2011 2:55 pm

Have you tried adjusting the sharpness setting on the LCD monitor?


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belg4rion67
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Re: GBS-8220 RGB TO VGA Converter

Postby belg4rion67 » Mon Apr 25, 2011 1:41 pm

Hi "Commissario", I've ordered Jammaboard too and I'm 'waiting for it...
Is possible that the small trimmers near connector need some adjustment for QL signal to work properly? Have you some suggest for their position?
Many thanks in advance.
Paolo


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vanpeebles
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Re: GBS-8220 RGB TO VGA Converter

Postby vanpeebles » Mon Apr 25, 2011 8:18 pm

Hehehe I've watched too many Maurizio Merli films. I never touched the adjustment trim things but I did notice that the sharpness LCD setting on my monitor effected the picture the most. Also I tried different resolutions as that effected the picture too.


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Andi B.
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Re: GBS-8220 RGB TO VGA Converter

Postby Andi B. » Thu Apr 28, 2011 4:39 pm

...the sharpness settings on the Monitor and resulution changes have effects but not improve the image.
Unfortunately the resolution of my monitor (1280 x 1024) is not supported by the converter card (only lower or higher).

But I think it is the quality of the <30 EUR converter itself which works maybe better with arcade machines and CRT displays (?)...

Here's a quick pic from the QL and a Siemens P19-2 where you can see the "shadows" at the color borders:
Attachments
QL_screen01.jpg


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Dave
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Re: GBS-8220 RGB TO VGA Converter

Postby Dave » Fri Apr 29, 2011 6:51 pm

What you are seeing there is that the red signal timing is slightly advanced. I do believe that board has an adjustment to align the R G and B channels timing just slightly, but I may be thinking of a different board.



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