QL-VGA v2

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mk79
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Re: QL-VGA v2

Post by mk79 »

I left a comment, too ;) And, at least one chip they got almost right... it's the rightway round at least ;)
JLCPCB_U5 wrong3.jpg
But hey, in the end the assembly fee for these boards was only like 22€ or something, that is nothing.
Last edited by mk79 on Tue Oct 06, 2020 2:28 pm, edited 1 time in total.


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NormanDunbar
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Re: QL-VGA v2

Post by NormanDunbar »

:D :D - that's only slightly wrong, at least 6 pins are soldered. Just in the wrong place.

Cheers,
Norm.


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mk79
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Re: QL-VGA v2

Post by mk79 »

So, unfortunately JLCPCB doesn't currently stock the FPGA anymore, so I had to go with another company. This increases the assembly fee by a factor of 10 :-o And where JLCPCB is a very automated process, this is all manual, with much back-and-forth between me and "Emily". But they did at least catch one component problem that slipped through the JLCPCB process. Anyway, a new batch has been ordered and payed for, hope it arrives within the next 2 weeks. Unfortunately too late for Christmas ;)

Cheers, Marcel


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varmfskii
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Re: QL-VGA v2

Post by varmfskii »

I just received my QL-VGA v2. So far I have tried it on 2 monitors and so far I am a bit disappointed. There are regions of the display (the same for both monitors I have tried) which are noisy. The full output of the QL is displayed, but these regions make some areas virtually illegible. Is this common to some monitors? Is this something anyone else has seen? Is there anything that can be done to alleviate the issue. I will, of course see if it is only these two monitors, or is is a problem across more of my available displays.


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Re: QL-VGA v2

Post by mselkin »

I am using the QL-VGA V2 on a cheap eBay monitor and I am not experiencing any issue at all. In fact, the picture quality is absolutely steady and crystal clear. Does your monitor's VGA input have an auto detect setting? Could your unit be faulty?


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Re: QL-VGA v2

Post by RWAP »

varmfskii wrote:I just received my QL-VGA v2. So far I have tried it on 2 monitors and so far I am a bit disappointed. There are regions of the display (the same for both monitors I have tried) which are noisy. The full output of the QL is displayed, but these regions make some areas virtually illegible. Is this common to some monitors? Is this something anyone else has seen? Is there anything that can be done to alleviate the issue. I will, of course see if it is only these two monitors, or is is a problem across more of my available displays.

Hmm -I wonder if it might be the power supply you are using with the QL-VGA or a faulty cable...

Marcel will have a better idea as he makes these!


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mk79
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Re: QL-VGA v2

Post by mk79 »

varmfskii wrote:I just received my QL-VGA v2. So far I have tried it on 2 monitors and so far I am a bit disappointed. There are regions of the display (the same for both monitors I have tried) which are noisy. The full output of the QL is displayed, but these regions make some areas virtually illegible. Is this common to some monitors? Is this something anyone else has seen? Is there anything that can be done to alleviate the issue. I will, of course see if it is only these two monitors, or is is a problem across more of my available displays.
I'm sorry to hear this, you are the first who mentions any problem. QL mode is very well tested and the picture should be rock-stable. Can you post a picture or video somewhere?


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mk79
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Re: QL-VGA v2

Post by mk79 »

Um, I just noticed your location. What ROM are you using?


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varmfskii
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Re: QL-VGA v2

Post by varmfskii »

I'm using a US ROM. We had a thunderstorm that night and now my QL has no display at all with anything, probably fried the 8301 :-(, It is a US QL, but I don't know which version of the ROM. Anyway here is a picture of the screen on an analog monitor.
https://photos.app.goo.gl/xTHTWgrzgpeomcCJ7
The image has the same characteristics on a couple LCD monitors I tried it on.


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mk79
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Re: QL-VGA v2

Post by mk79 »

Yeah, I guess the QL-VGA "screen-saver" is displayed well when the QL is switched off, this is not a monitor issue.

Amazingly little details are known about how exactly NTSC QLs really work, and I don't have one either, so QL-VGA probably cannot handle them as-is. But when you switch to a "normal" ROM, be it MG, JS or Minerva (my suggestion), it should revert to the standard 50Hz behaviour and QL-VGA should work fine with it. This has other advantages, too, because frankly no QL program cares about 60 Hz, they all assume 50 Hz as 60 Hz is just too uncommon.

If you want to try something first, issue "POKE 98403,0" in Basic and check if the picture improves. Hope you get your QL to work again first, of course. By the way, NEVER hot-plug any display to the QL, not QL-VGA and not any RGB monitor. Chances of frying the ZX8301 are high.


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