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Frank.Bullitt

Can I get the monochrome high resolution signal from an RGB SCART cable?

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Hello,

 

I've got an Atari 1040STE with a SCART cable going into my OSSC.

 

Is there a way I can add a switch to this cable to enable high resolution monochrome video output? And if so, will this be safe to output to my OSSC, or will I need to modify it to make it a more standard signal?

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OSSC specs say that it supports VGA mode. So, monochrome mode should work with it - but not via Scart cable, where monochrome signal is not connected for sure. You need another cable for mono mode - like ST-VGA, or combined ST-Scart & VGA switchable. Later with 3 connectors.

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19 minutes ago, ParanoidLittleMan said:

OSSC specs say that it supports VGA mode. So, monochrome mode should work with it - but not via Scart cable, where monochrome signal is not connected for sure. You need another cable for mono mode - like ST-VGA, or combined ST-Scart & VGA switchable. Later with 3 connectors.

Thanks for the quick reply 🙂

 

 

There is a cool VGA socket being sold on Exxos UK that I've been looking at but I was hoping there was a SCART option available, as the SCART cable I purchased has the L and R audio jacks built in, which is much more convenient when connecting to the OSSC.

 

https://www.exxoshost.co.uk/atari/last/storenew/#0107

 

The OSSC has a 3.5mm audio in socket, but it's being used by the Atari 7800 at the moment.

 

I was wondering if there was a way to splice in a switch to make pin 4 ground. Bit new to this morning stuff but I'm having a real blast 😁

 

 

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Of course, if you can open connector to Atari video out, can add there monochrome line and mono switch line - then can do switch and VGA ...

Hmm, and probably need H and V sync lines too .

Google for "atari st video monochrome to vga"

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8 hours ago, ParanoidLittleMan said:

Of course, if you can open connector to Atari video out, can add there monochrome line and mono switch line - then can do switch and VGA ...

Hmm, and probably need H and V sync lines too .

Google for "atari st video monochrome to vga"

I've ended up going for a good quality Gold VGA cable and the VGA socket from Exxos as there seems to be interference that I'm hoping is just the scart cable.

 

I'll use an RCA to 3.5mm converter and a 3.5mm splitter for both the 7800 and ST to be connected at the same time.

 

Thanks 🙂

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On 7/30/2020 at 12:26 PM, Frank.Bullitt said:

I've ended up going for a good quality Gold VGA cable and the VGA socket from Exxos as there seems to be interference that I'm hoping is just the scart cable.

 

I'll use an RCA to 3.5mm converter and a 3.5mm splitter for both the 7800 and ST to be connected at the same time.

 

Thanks 🙂

With my OSSC in ST High, I had to tweak some of the settings (you can probably find the posts on the ossc forum).  Then it looked fantastic.  Otherwise you will probably get vertical 'pinching' of the display.

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On 7/30/2020 at 9:58 AM, ParanoidLittleMan said:

OSSC specs say that it supports VGA mode. So, monochrome mode should work with it - but not via Scart cable, where monochrome signal is not connected for sure. You need another cable for mono mode - like ST-VGA, or combined ST-Scart & VGA switchable. Later with 3 connectors.

Actually the ossc(and the new Retrotink 5x also) should be able to convert Mono/Highres via the scart connector. All the inputs(scart/YPbPr/VGA) of the ossc accept the same frequencies, but scart and YPbPr have the added benefit of the LPF, so the image should be even better than via VGA. There is even a product available for the exact purpose of feeding VGA signals to scart. https://www.retrorgb.com/hd15-2-scart-adapter.html

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Hi there, so you think that using a switch (quad inverter) should be possible to send color & mono signals to the SCART input on the OSSC? 

If that's possible then I would want to try it. 

I was thinking on building a RGB cable with a quad inverter switch with a SCART connector and a VGA connector, and then connecting the VGA (with the mono signal) to the VGA Input on the OSSC.

 

Thoughs?

 

Andres.

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1 hour ago, Andres Vettori said:

Hi there, so you think that using a switch (quad inverter) should be possible to send color & mono signals to the SCART input on the OSSC? 

If that's possible then I would want to try it. 

I was thinking on building a RGB cable with a quad inverter switch with a SCART connector and a VGA connector, and then connecting the VGA (with the mono signal) to the VGA Input on the OSSC.

 

Thoughs?

 

Andres.

 

Your cable would just need a switch to short the mono pin to ground on the ST's monitor out port to put the ST into mono mode.

 

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What you could do is build a version of Ube Switch (https://github.com/planeturban/ubeswitchmk6) with a DIN13 output instead of VGA, should be pretty straightforward. I guess, it could also be retrofitted directly inside the Atari. As for using mono over scart with OSSC, yes it works well, used it a few times.

 

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Ok, thanks for confirming that monochrome works trough SCART. 

I think I still would need an inverter switch for 4 circuits. One for the MONO detect signal (pin 4 on the Atari RGB) and another 3 to route RGB signals (pins 6, 7 and 10 on Atari RGB din) or Monochrome signal (pin 11 on Atari RGB din) to the RGB CART pins (pins 7, 11 and 15 on SCART).

I have read that for connecting this SCART cable to an upscaler like OSSC you need to mix Vertical & Horizontal SYNC signals (pins 9 and 12 on Atari RGB din) to feed the pin #20 on the SCART connector. 

Is this the way you made it work for Monochrome over SCART, @ojanhk? Or you used a standard SCART cable (suitable for a SCART TV) that feeds the Composite SYNC (pin #2 on Atari RBG din) to pin #20 on the SCART connector? 

 

Thanks!

Edited by Andres Vettori

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I did this using an H5 Atari replica, which provides C-Sync, H-Sync and V-Sync to pins 2, 9 and 12, so I actually need to check the cable. I will have a look tonight, it’s basically a standard Atari cable (not aftermarket) as provided in the box of a PAL 1040 STE.  

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1 hour ago, ojanhk said:

I did this using an H5 Atari replica, which provides C-Sync, H-Sync and V-Sync to pins 2, 9 and 12, so I actually need to check the cable. I will have a look tonight, it’s basically a standard Atari cable (not aftermarket) as provided in the box of a PAL 1040 STE.  

Thanks a lot! Will wait for your comments.

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On 8/31/2021 at 6:51 PM, Andres Vettori said:

Perfect!  Thanks a lot! 

 

Well, this is the RGB - SCART cable (with COLOR/MONO switch) I have designed and built...  Let´s hope it works. 

I'm waiting for my OSSC to arrive and test it, will keep you posted.

 

Andres.

 

20210905_124403.jpg

20210906_101737.jpg

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4 hours ago, ojanhk said:

Respect, soldering these DINs is a real pain. 

 

 

Je je je...   Yes indeed.... real pain....  more so if you try to do it properly and get a quality cable with some durability!

 

Thanks!

20210906_200926.jpg

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SUCCESS!!!   

 

I have received my OSSC and tested my newly built RGB / SCART switch cable and it worked!!!  

 

I'm now playing with the settings to find the best picture on all video modes, but I'm extremely happy!!

 

Best regards!

20210908_222601.jpg

20210908_225057.jpg

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Hi All!  I'm noticing that most of the video modes shows some "wobbliness" or "waves". 

I have tried playing with some settings but could not found one that fixes it. 

So I'm thinking this behavior might be related to some video signals not coming through resistors as recommended in most RGB / SCART cables, in particular for the color (RGB) signals (although color levels seems to be OK) or CSYNC (from pin 2 in RGB to pin 20 in SCART).

 

Any pointers? 

 

Thanks!

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Btw, there are way too many topics opened on the same subject at the moment, might be good to merge these. 

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17 hours ago, ojanhk said:

Did you go through Exxos mandatory fixes, including video fixes? It might help.https://www.exxoshost.co.uk/forum/viewtopic.php?t=1585

Wobbling might be due to OSSC settings too or cable interferences. If your cable is not shielded, you might “wobble” at 50hz or 60hz depending where your live.  

 

 

I did all mandatory fixes except for the video ghosting fix, as my STE don't show any ghosting.

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