gordonfish wrote: ↑Fri Nov 27, 2020 10:09 pm
Been reading through this thread, and while I understand the desire to have absolutely perfect-like-original output, it really feels to me like people really forget how inconsistent composite (as well as S-video and esepcially RF) could be.
I remember back in the 90s of doing an experiment with a couple of friends, who each brought their NES (USA front loaders, all the same model) that were each connected via composite one at a time, by quickly swapping the same RCA video cable between them. The point of the experiment was to see if they all ran at the same speed, to see if they all looked the same, and what, if any, differences there were.
What I recall is each NES's composite output did vary slightly in color, and one of the NES units was visibly darker (not by a whole lot) than the other two. Artifacting also varied a from one NES to the others. The text in the SMB1 title screen I recall looked a little different between the systems, on at least one of the units looking slightly smoother than a third one.
The real take away here is that it was never the exact same image. I believe that people today have gotten so used to having a consistent video picture on HD and 4K televisions, that many of us forget how analog output generation, as well as CRT displays, could vary quite a lot.
So I humbly submit that if the output can vary from one genuine NES to another, than seeing slight differences between a real NES and the composite adapter feels more inline with the reality of analog output generation. I agree there could always be room for improvement (like what was said earlier in this tread about better syncing once cores get updated with that ability), though currently it looks like we can get really close with some of the adapters posted here and elsewhere.
The quest for 100% consistency where it didn't exist between real consoles, isn't a realistic goal, imho, especially when you factor in 1) all the different composite generation hardware used in different game and computer consoles that used it, as well as 2) runs and revisions of the same consoles could have used varying components for analog video generation, giving way to even more potential inconsistency between units of the same console.
I gotta come back for this since I feel like I'm being literally gaslighted on this, and people are incorrectly being led to believe I'm delusional or something or just misremembering. This is not a "slight difference", this is a directly demonstrable severe difference. I can't test it anymore since I literally gave antonio's adapter away for free since I didn't feel it was right to sell it for anything since I knew of it's significant flaws. Also, unlike antonio, I actively informed the person I gave it away to for free that it had significant issues. Because that's what people with some shred of *integrity* do.
I have now tested the same games on a Sega Mega Jet, Genesis Model 1 (VA6), and a JVC X'eye, and none of them exhibit the same behavior, across all 3 CRT's that span over a decade of manufacturing and 3 different brands. I have to say that it feels pretty frustrating to be told that I have false memories when I have done direct live comparisons with original hardware in person. Again, let's be clear, this is not dot crawl. This was rainbow luma interference, as described here -->
https://www.renesas.com/us/en/document/ ... techniques
- colortrap.png (85.9 KiB) Viewed 7351 times
Colors from the luma signal are bleeding into the composite signal, because either there is now YTRAP or there is an insufficient YTRAP, is the most likely cause, but whatever.
If you are thinking that white borders around characters avatars in games like Shining Force II had a constantly moving wave of rainbows flying over them, I gotta dispute that, since that effect literally didn't happen across 3 different systems now on 3 different CRT's, for the same platform (Sega Genesis) with the original hardware I have on hand. The only time that happened was with antoniovillena's composite adapter. The only time I saw this super jarring effect that generates problems. Maybe you all are playing on PAL CRT's, I'm not.I switched his to NTSC, I tried different jumpers, I tried multiple permutations of settings combinations, I tried removing the jumper (obv didn't work), so many more things as I've already said here.The frequency of the Rainbow chroma effect changed with 3.3v vs 5v on the vga jumper.
Fact is if you say "it generates the same signal as original hardware", you'd better be right, since it's kinda insulting when it obviously does not. I demonstrated it doesn't, dshadoff has also seen significant deviation from original hardware and they are an expert on the PC-Engine video output for the core development.