[Coco] Using Roy's vga adapter with other computers

Steven Hirsch snhirsch at gmail.com
Sun Oct 25 09:13:18 EDT 2009

On Sun, 25 Oct 2009, Bob Devries wrote:

> Isn't the Commodore 128's RGB port a digital one? That is, RGB-I instead of 
> Analog RGB?

The C128 is indeed a digital RGBI signal.  In order to get the proper 
color mapping, you need to build a simple 2-chip adapter that converts to 
a quasi-analog signal.  Wolfgang Moser (Womo) published a schematic and 
PCB layout for just such a device.  I built one on perf-board and use it 
to connect my C128 to the same Wei-Ya RGB/VGA converter that works so well 
with my CoCo.

With a little tweaking of level trim-pots, you can get the entire C128 
color pallete to display faithfully.



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