Sega MegaDrive Rainbow Effect in NTSC mode

[synrgy87]

I done the 50/60hz switch mod on my MK1 Sega megadrive

works fine in 50hz pal mode, but when i switch to 60hz i get nice full screen image but a weird Rainbow effect across the whole screen, im wondering if anyone else has had this?

im using composite for video out to my lcd tv/monitor, is this because im not using RGB

[bart_simpson]

Yes but theres a fix http://www.youtube.com/watch?feature...&v=6pgUVtUQJ3k

[synrgy87]

haha cheers for that, knew there was an issue with image being black and white, but i had colour, just kinda rainbowy colour, tried it on another tv and it was black and white. i'll eventually have this megadrive screwed back together.

[sonik]

My japanese model 1 ntsc console have a horrible problem with rainbow banding.



It's possible to fix it?

[Lum]

Trying a 32X might work.

RGB converter of some kind would be the largest potential for improvement. But that's expensive to get setup in our countries.

[sonik]

This system works OK with an rgb to component conversor. 32x works too.
This picture was taken while it was connectec using s-video.

The fix linked by bart_simpson will work on my unity too?

[segasonicfan]

great page for info on this:
http://www.chrismcovell.com/gotRGB/screenshots.html

The effect is caused by a lot of things, mainly a problem with the subcarrier input. You can adjust it, but its a tradeoff for picture clarity.

[bart_simpson]

Should be possable seems like sega 315 dry jonits sounds mad but that's mostly the fault sometimes can be the video encoder i have a crappy ntsc va7 dont like sonic 3 pal.

[Lum]

for sonic 3 pal at 60hz correctly, you need to bypass its initial lockout check. like with game genie.

a switch to 60hz once started won't work.