MiSTer FPGA Forum

Hi,
I own a NES PAL Version since I was kid and by playing with Gradius game, there is always been a very cool "shining stars" effect with the original console using both rf or composite output.
I actually have a Mister connected to a 21" 15KHz Trinitron crt with scart RGB using Direct video (which looks superb really defined and firm image!!!) but I've noticed I'm missing the "shining stars" effect. Instead of shining stars I get a orange and blues stars.
So I've tried with a cheap standard hdmi to composite converter (https://www.amazon.it/gp/product/B07PH4K2DC/) to see if it could bring back this effect, now stars are more white but still won't shine. Maybe it's caused by the converter internal conversions and I need a more "real" raw composite output. I've also noticed images are not as firm as when using Direct Video.

Some links found on youtube to get an idea of the effect I'm talking about:

composite/rf
https://www.youtube.com/watch?v=SUIG3hhLD3E

rgb
https://www.youtube.com/watch?v=Wmpi64_RpnE

My questions:

• I'd like to try with Antonio Villena's Composite adapter (https://www.antoniovillena.es/store/pro ... o-adapter/) but I'd like to know first if can bring the composite output as the one I have on NES. Is there anyone owning it who could gently make ths "shining stars" tests? In case would it work with Direct Video?
• Woudn't it be cool, in terms of preservation, to have a native composite out of Mister? Do you think it might be feasible ?

I'd really like to get this out since the composite is what I remember from my childhood both for the blending and the colors (like Metroid) .

Thanks in advance and kind regards to all

mindfiedx wrote: ↑Mon May 31, 2021 5:36 am - Woudn't it be cool, in terms of preservation, to have a native composite out of Mister? Do you think it might be feasible ?

barfood wrote: ↑Mon May 31, 2021 12:47 pm I have AV's adapter, I'll try to capture and share the test results tonight.

mindfiedx wrote: ↑Mon May 31, 2021 4:03 pm

barfood wrote: ↑Mon May 31, 2021 12:47 pm I have AV's adapter, I'll try to capture and share the test results tonight.

Thanks, it would be great!

max1602 wrote: ↑Tue Jun 01, 2021 3:28 pm Has there always been a vga to composite adapter?
Or is it a new thing?
Has it been made specifically to downgrade the mister signal?

mindfiedx wrote: ↑Tue Jun 01, 2021 9:24 pm @barfood, btw from you video it looked like your mister composite was very good. Are you experiencing "moving dot crawls" with the AV's adapter?
Some hours ago I've ordered one but after reading those long thread I'm confused. Is there any video showing that? I mean I've found a relative recent video about it (1 month ago) that looks very promising and image looks very still I havent noticed any moving dot crawls: https://www.youtube.com/watch?v=FU41X9_zcbQ
https://www.youtube.com/watch?v=lnXKFwwIh58
Is there a new version ?

mindfiedx wrote: ↑Thu Jun 03, 2021 7:18 am Moreover it has clock detection on VSYNC pin. If a clock is detected this clock override the PAL or NTSC crystals.

paulbnl wrote: ↑Thu Jun 03, 2021 2:07 pm

mindfiedx wrote: ↑Thu Jun 03, 2021 7:18 am Moreover it has clock detection on VSYNC pin. If a clock is detected this clock override the PAL or NTSC crystals.

Does the current version that he sells have that or is that in a future version? I don't see anything about that in the description on his shop.

mindfiedx wrote: ↑Thu Jun 03, 2021 2:47 pm

paulbnl wrote: ↑Thu Jun 03, 2021 2:07 pm

mindfiedx wrote: ↑Thu Jun 03, 2021 7:18 am Moreover it has clock detection on VSYNC pin. If a clock is detected this clock override the PAL or NTSC crystals.

Does the current version that he sells have that or is that in a future version? I don't see anything about that in the description on his shop.

Yes, he told me via email that the version is actually selling does have it. Maybe you can write him asking for more details.

mindfiedx wrote: ↑Thu Jun 03, 2021 7:18 am Moreover it has clock detection on VSYNC pin. If a clock is detected this clock override the PAL or NTSC crystals.
If one day Mister Fpga cores would generate this clock on VSYNC pin the adapter would automatically work using that clock and avoiding the "moving dot crawls" behaviour so I wouldn't have the need of replace it with a new one.

paulbnl wrote: ↑Mon Jul 19, 2021 2:22 pm

mindfiedx wrote: ↑Thu Jun 03, 2021 7:18 am Moreover it has clock detection on VSYNC pin. If a clock is detected this clock override the PAL or NTSC crystals.
If one day Mister Fpga cores would generate this clock on VSYNC pin the adapter would automatically work using that clock and avoiding the "moving dot crawls" behaviour so I wouldn't have the need of replace it with a new one.

I bought Antonio's VGA->Composite adapter after he confirmed that the clock override would work on his current model.

Unfortunately he failed to mention that he never tested this on MiSTer, only on his ZXDOS board.

I modified some cores to send the clock to the VSync pin but unfortunately it doesn't work at all.

Antonio is reluctant to help fix this because he says he doesn't have time and he says it works on the ZXDOS board so it should work on MiSTer. Thus he is implying that I am not generating the clock correctly.

I asked him 2 weeks ago if he could verify with an oscilloscope that the clock on the VSync signal is correct but he didn't answer me anymore.

antoniovillena wrote: ↑Mon Jul 19, 2021 5:38 pm I have answered all your emails. The ZXDOS board has exactly the same circuit for video DAC. Also I have tried the clock detecting circuit during the prototype phase. So using an external clock on VSYNC override the internal crystals.

paulbnl wrote: ↑Tue Jul 20, 2021 8:41 am You haven't answered the last email I sent you 2 weeks ago where I asked you to check the clock signal on the VSync pin with an oscilloscope.

I have added an 14.31818Mhz clock to the PLL in the SNES core and sent it to the VSync pin. Why doesn't it work?

antoniovillena wrote: ↑Tue Jul 20, 2021 9:16 am It's not a good clock. You can check with an oscilloscope. You can try with a proper one for example with an external oscillator and this will work

paulbnl wrote: ↑Tue Jul 20, 2021 10:09 am Did you actually check the clock with an oscilloscope or did you just guess?

There is no reason for it to be a bad clock because it is coming directly from the PLL. Unless the VSync line has interference on the MiSTer IO board that the ZXDOS board doesn't have.

If there is someone here that has the time and equipment to check the clock on Vsync from the MiSTer IO board then reply here and I will post the modified core.

barfood wrote: ↑Tue Jun 01, 2021 1:15 am Here you go! The video is still processing, but by the time you see this post it should be viewable: https://youtu.be/4kIeOnPOVd0

Please forgive the rough filmography, hopefully it provides the insight you were looking for. From my eyes, the answer seems to be: no, the stars in the background of Gradius do not flicker as much on the MiSTer's composite signal as the original NES (or, in my case, the AV Famicom).

Has anyone got the chance to check out the Gradius stars with the new composite cores /boards from MikeS ?

mindfiedx wrote: ↑Fri Feb 24, 2023 8:22 am

Has anyone got the chance to check out the Gradius stars with the new composite cores /boards from MikeS ?

Sadly stars don't sparkle on NESYC with Misteraddons active Y/C board. Stars are also blue and orange. Too clean ha! It's really too bad. I love these kinds of noisy signal artifacts that "enhance" the visual so this is unfortunate heh.... But Y/C composite stuff look super nice in general.

I have been wondering if some of the Y/C cores look cleaner than the original hardware. I've seen it suggested that is the case for NES.

Composite video is just generally crappy and MikeS handles it the best way possible by using a luma trap and careful tuning in the cores to combine Y&C. To handle it the way the NES does natively, you're going to need to rewrite part of the core and need a different analog board that would output at the required levels to be in spec with NTSC and PAL. The end result will be worse for 99% of NES games as there's only a small handful that take advantage of artifacting at all.

Mikes' tuning of composite is fantastic and look cleaner than real consoles for many cores. Most definitely not crappy. Wii composite is even cleaner. But they are certainly not accurate. Composite look different even between different models of FC/NES. Even more so on RF. I'd love to see someone go sicko mode and come up with MDFourier style measurements for video signals that could be use for simulating different model variants.