[Coco] Composite Video Mod for CoCo1

[Fedor Steeman]

Hi Daniel,

If you search the list, you can read that I posted about this subject a few
times already earlier.

In short, I acquired a CoCo2 with such a composite video mod that worked
fine, until I transported it somewhere at a certain moment. I think
something came loose or short-circuited, because now I only get a black
screen. It can probably easily be fixed, but I am not that skilled enough
to do it.

The video mod is based on the following manual (in Dutch):
http://www.steeman.dk/CoCoManuals/VideoMod_(KoenVaartjes).pdf

Here are some pictures of it:
https://picasaweb.google.com/115146243402896969496/CoCoVideoMod?authuser=0&authkey=Gv1sRgCKCWiaq64ompugE&feat=directlink


Cheers,
Fedor

On 3 December 2012 13:48, Daniel Campos <daniel.campus at gmail.com> wrote:

> Hello,
>
> Since I got the Color64 (Coco1 clone) his image, even already having a
> composite video output, have always disturbed me with a crap image
> compared to other CoCo machines. So I began to try to correct that and
> removed the entire transcoder analog pcb that came with the computer
> and used the schematic bellow to try to have a better composite
> output:
>
> http://www.victortrucco.com/Diversos/MC1000/SaidaAV.JPG
>
> The schematic above is largelly based on the driver for color
> composite video that is showed on the 6847 datasheet. After build the
> mod, image is great on text mode, sharp and crispy, the problem begans
> when I got to the graphics mode using artifacting. For example, on
> Outhouse, the initial screen should be red, but appears with a very
> pink saturated color, it's impossible to read. Other games, like
> Draconian and Galagon got very saturated too.
>
> My question is, someone here have done any of the scematics bellow and
> worked fine on a LCD monitor with composite video ?
>
>
> http://www.retrocomputers.eu/wiki/index.php/Tandy_TRS-80_Color_Computer_(CoCo)_Composite_Video_Mod
>
>
> http://sd2cx1.webring.org/l/rd?ring=coco;id=1;url=http%3A%2F%2Fwebspace%2Ewebring%2Ecom%2Fpeople%2Fvt%2Ftheother_bob%2Fcoco_page%2Fccprojects%2Ehtm
>
> Any suggestion would be higly appreciated. :)
>
> Thanks,
> Daniel
>
> --
> Coco mailing list
> Coco at maltedmedia.com
> http://five.pairlist.net/mailman/listinfo/coco
>