[Coco] Re: CoCo 3 Monitor

[Torsten Dittel]

> To do that, what you need is called a "clock doubler" as most VGA monitors
> made in the last 10 years don't support the slower NTSC clock rate.

Solutionb using the following chips from AverLogic:

3-channel analog RGB -> digital RGB888 ADC:

http://www.averlogic.com/password/AL875_Data_Sheets.PDF

digital RGB565 -> analog VGA conversion:

http://www.averlogic.com/password/AL250_251_Data_Sheets.PDF

Here *has* been a reference design (has anyone made a local copy? It
disappeared...)

http://www.2k1.co.uk/products/averlogic/www1/AL250/AL875_250.pdf

> I've seen external "clock doublers" (Think of hooking a VCR to an SVGA
> monitor -- not a CoCo 3 -- makes the Googling a bit easier... ;-) ) for
> about $65 + shipping.

Most of those accept only

- composite video => bad quality
- component (aY/Pb/Pr) or S-video

We'd need one which is able to process RGBHV 16kHz (hard to find).

Torsten