[Coco] VDG weirdness

[John W. Linville]

On Mon, Oct 12, 2015 at 10:16:34PM +0100, Phill Harvey-Smith wrote:
> On 12/10/2015 19:21, Zippster wrote:
> >Nice job Phill.  The output looks really good.
> >
> >Love the true black background on the inverted alphanumerics.
> >
> >So this is doing Y, øA, øB to 15KHz RGB?
> 
> Yeah takes øA, øB and CHB, and converts to a 4 bit digital output then takes
> Y amplifies it and converts to pixel on / off. At the suggestion of some of
> the Atom people I force CSS to 0 going into the 6847 and then used the CSS
> from the 6821 into the CPLD to change the colour sets there. This is because
> the voltages out of the 6847 as slightly different depending on CSS, doing
> it this way means that the 6847 always thinks it's CSS 0.
> 
> Output is then converted to TTL RGB and fed via a SCART to a TV.

That's pretty cool, Phill!  After seeing the old Atom color boards
I had thought to do a similar project at some point.

Do you have any plans to market such a board?

John
-- 
John W. Linville		Someday the world will need a hero, and you
linville at tuxdriver.com			might be all we have.  Be ready.