kubilus1 wrote:Not dithering, but horizontal striping.
Same difference. It's just a different form of dithering.
On my system, I don't see rainbow artifacting, maybe I would in larger swaths of colors, but some of the colors do not match exactly what I see on the emulator, which is not a surprise.
Luma signal is not a multiple of the color burst signal, so some TVs are better at filtering this out and some are worse. Your mileage is going to greatly vary depending on the quality of the TV set (and its filters), including "rainbowing" and "muddy" colors.
This technique was used quite a lot on older computers, along with quite a few Genesis games to add more colors and transparency effects. You aren't going to see this used 100% of the time usually, but more of a sprinkle here and there.
It's only sprinkled and not heavily used for several reasons: It doesn't work in PAL land, and RGB was a valid option right on the console itself (no mod needed).
In regards to RGB, I look at it like this. Your Genesis or Megadrive was never intended to be used like that. It's fine that we can hack them nowadays, but you do lose some of the effects you are supposed to be able to get out of your sega:
http://nerdlypleasures.blogspot.com/201 ... osite.html
I think you're confusing popular platform with intended platform (signal output). If RGB wasn't an option, they wouldn't have put amp'd RGB right at the back of the system for direct use. The Genesis video encoders are just a different style than dot crawl ones (each have their own advantages and disadvantages). That doesn't mean Sega purposely made the MD with this approach in mind. Matter of fact, look at the whole library - 98% games barely use it. Only late gen games start using more so. If Sega wanted a system with specific NTSC artifacting colors, they would have used a 7.159mhz dot clock and not a 6.711mhz dot clock.
If you want to see a true effect in action, check this out:
http://www.youtube.com/watch?v=g51QqurGqg0
A resolution mode that's actually double the subcarrier signal. Perfect NTSC artifact colors (7.159mhz dot clock). NEC included an option to turn off the dot crawl, have this res mode, and never used it. RGB on that system was never official either (later systems don't even have a back plane to access it). By the way, that 4bit tiles/sprites and 512 RGB color just like the Genesis (just more subpalettes).