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Commodore 128 RGBI to RGBA Adapter by Digital Audio Concepts

Commodore 128 RGBI to RGBA Adapter by Digital Audio Concepts

RGBI to RGBA Adapter by Digital Audio Concepts
This is taken from the Digital Audio Concepts website -

"...I've been working on an adapter to connect a C128's 80 column video port directly to a video-game-to-VGA upscaler board such as the GBS-8200 or 8220 (i.e. ones sometimes called "JAMMA" boards). The C128 produces digital RGBIHV output pretty much identical to the old CGA video standard, while some of those upscaler devices require analog RGB signals (without a separate intensity signal), and composite H+V sync. This board seeks to address this mismatch.
My intent here is to reasonably duplicate the standard C128/CGA palette as described in the article on Wikipedia, including a suitable "brown fix" circuit.

At one end is the C128 video port connection. At the other end is a row of five holes to receive the wires from the scaler board's video-input pigtail, and two more holes next to t…