View Full Version : How to get rid of the rainbow effect on ColecoVision composite?
bacteria
01-13-2010, 06:39 AM
Took video off pin 36 of the ColecoVision graphics chip; got composite, but there is a rainbow effect on the image - I believe this is usual from this old chip.
What, if anything can I do to get the image normal and stable, no rainbow effect?
This is what I mean:
http://i46.tinypic.com/2z5lwcw.jpg
Example from someone else's post:
ColecoVision composite:
http://spatula-city.org/~im14u2c/images/parsec_ntsc.png
What it should look like:
http://spatula-city.org/~im14u2c/images/parsec_emu.gif
Platinum
01-13-2010, 03:09 PM
That image of Parsec looks like the TI-99/4A Parsec.
Anyway, even with S-video I tend to get that effect on some consoles.
bacteria
01-13-2010, 04:24 PM
Correct, image was that, in a thread on Atari Age discussing the same graphics chip. Image is similar to the image I was getting, so posted it as comparison.
Normally I am entirely behind using original hardware, however this might be a rare occasion that emulation rules!
Leo_A
01-13-2010, 06:52 PM
Might be worth browsing around AtariAge. There's been a good bit of discussion there about composite mods for the Colecovision recently and maybe someone can help you out.
I don't have anything else to provide since I play on a Coleco ADAM that was originally built with composite capabilities. So I tend to ignore discussion on video mods for it as a result.
Ed Oscuro
01-13-2010, 08:13 PM
This thread (http://www.atariage.com/forums/topic/143059-colecovision-component-video-mod/) seems to be relevant (I've taken a look at the cached version of the page) although I'm not sure they got the result they wanted.
I don't trust that TFT LCD screen but it's probably the usual component image signal blending problems, in which case you might be able to just run the signal through a comb filter (find a device which has one, like a laserdisc player plug into that, and then into your monitor; some TVs have their own comb filter but this apparently isn't one). There's very little lag (which should amount to merely just lines of video, not even full frames), if you can make that work.