VGA for low and medium res?

All information relating to connecting your ST to a modern TV/monitor.
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PeteW
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VGA for low and medium res?

Post by PeteW » Sat Oct 20, 2018 10:02 pm

Is there a reason why all the ST to VGA cables I see are for high res only?

Is connecting an ST to VGA for low and medium res more complicated than using the r, g, b, h sync and v sync signals from the monitor port?

Thanks - apologies if discussed before

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Re: VGA for low and medium res?

Post by stephen_usher » Sat Oct 20, 2018 10:06 pm

VGA doesn't support the slow scan rates used by TVs. There are a few VGA monitors which could handle this and a very few LCD monitors which do too, more by luck than judgement.
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PeteW
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Re: VGA for low and medium res?

Post by PeteW » Sat Oct 20, 2018 10:09 pm

Thanks - I've been given a 32inch LCD vga/hdmi monitor so I wanted to use it for the ST if possible. I'll knock up a cable and see if I get lucky...

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rubber_jonnie
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Re: VGA for low and medium res?

Post by rubber_jonnie » Sat Oct 20, 2018 10:38 pm

If you look at the VGA cable/adapter market, there are many out there, some which are Hi-Res and some are Low/Med Res, such as:

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

A similar switch is made by Centurion Tech, and there are others available.

Hi-Res will work with virtually any VGA display you care to throw at it, however Low/Med Res requires that you have a 15Khz vertical sync. A list, albeit incomplete, can be found here:

http://15khz.wikidot.com/

And there are other lists like it if you spend a bit of time with Google.

Your 32 incher will almost certainly work fine with Hi-Res, but is unlikely to support 15Khz. You could try a SCART to HDMI adapter, that should work with Low/Med Res and your HDMI port.
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PeteW
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Re: VGA for low and medium res?

Post by PeteW » Sat Oct 20, 2018 10:48 pm

Thanks for the info. I think I've found a way around it - hidden on another part of the monitor are both composite and component rgb phono inputs. So they should work fine if I just plug in the relevant rgb signals to them I guess?

Has the advantage of meaning my spectrum should work with it too!

Unfortunately it doesn't have built in speakers so I'll find an old set of PC speakers to do the job :)

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Re: VGA for low and medium res?

Post by troed » Sun Oct 21, 2018 8:26 am

PeteW wrote:
Sat Oct 20, 2018 10:48 pm
Thanks for the info. I think I've found a way around it - hidden on another part of the monitor are both composite and component rgb phono inputs. So they should work fine if I just plug in the relevant rgb signals to them I guess?

Has the advantage of meaning my spectrum should work with it too!

Unfortunately it doesn't have built in speakers so I'll find an old set of PC speakers to do the job :)
Component isn't RGB

(but the fact that your screen supports composite raises the chances it _might_ do 15KHz over the VGA port. By no means assured though)

PeteW
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Re: VGA for low and medium res?

Post by PeteW » Sun Oct 21, 2018 9:25 am

troed wrote:
Sun Oct 21, 2018 8:26 am

Component isn't RGB

(but the fact that your screen supports composite raises the chances it _might_ do 15KHz over the VGA port. By no means assured though)
Just looked component up - I never knew that (learn something new every day!). Until now, I always assumed component and rgb to be the same thing!

I'll give vga a try...

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Re: VGA for low and medium res?

Post by IngoQ » Mon Oct 22, 2018 11:57 am

If this does not work, it might be worth a shot to get a cheap component to rgb converter (also called YUV2RGB). It is more likely, that the display will accept 15kHz there.
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