6 replies to this topic

[juice2839]

I have been working on this coco 2 rgb mod for sometime.. I unfortunately got laid off last week, but  on the flip side, with the extra time, I have finally got this working perfect.  It basically turns the r-y b-y into RGB. Then I run it into a scart to hdmi converter. The picture is of 1080i output. Check it out.

 

 

Attached Files

•  IMG_0410.JPG   2.41MB   23 downloads
•  IMG_0411.JPG   1.99MB   16 downloads
•  IMG_0412.JPG   1.59MB   14 downloads

[JamesD]

That's the cleanest CoCo 1/2 video I've seen.
Is this like computer monitor RGB or component TV video?  

[juice2839]

That's the cleanest CoCo 1/2 video I've seen.
Is this like computer monitor RGB or component TV video?  '

 

It's the cleanest video you can get. Yes computer monitor RGB, although I don't have a RGB monitor to test it on only a scart(RGB) to hdmi converter.

[juice2839]

I don't see any reason why I couldn't also use the r-y b-y and y signals before the RGB converter circuit to run the component inputs on a TV though. 

[Zippster]

Schematic?

 

This is still 15.7khz video, so converters (with a scan-doubler in there somewhere) will have to be used to get it on a VGA monitor.

 

Still, this is analogous to the RGB video on a CoCo3.  Unfortunately as with the CoCo3, the composite artifacts relied on by most games

wouldn't work, but high quality composite and s-video can be derived from RGB, perhaps using one of Analog Devices ICs.

 

- Ed

[juice2839]

Schematic?

 

This is still 15.7khz video, so converters (with a scan-doubler in there somewhere) will have to be used to get it on a VGA monitor.

 

Still, this is analogous to the RGB video on a CoCo3.  Unfortunately as with the CoCo3, the composite artifacts relied on by most games

wouldn't work, but high quality composite and s-video can be derived from RGB, perhaps using one of Analog Devices ICs.

 

- Ed

 

You could use an AD724 of AD725 to convert the RGB to composite video. I am not sure if you would get the artifact's back using that or not (Not on an LCD for sure). You can use one of the many cheap RGB to VGA converter out there if you wanted to use your Coco on a VGA monitor. I personally wanted this so that I could use my COCO 2 with a new LCD TV and have a perfect picture. I plan to make a few kits and offer some upgrades so I am keeping the schematics out of the public domain for the moment. 

[Barry Nelson]

I built a composite output circuit for a CoCo 1. The quality is not as good as RGB, but it does do the artifact colors correctly.

 

https://hackaday.io/...te-video-output

 

Here are some pictures: