[Coco] RGB to XGA (Bruce Borer)

[Bruce Borer]

Hi Andrew,
   You seem to be asking about changes to the CoCo itself.  My converter
just displays what the CoCo3 produces, including making WIDTH 80 readable
on readily available monitors.

Bruce

On Tue, Dec 23, 2025 at 11:04 PM Andrew Ayers via Coco <coco at maltedmedia.com>
wrote:

> Though as you said, the Pico probably couldn't handle it, it would be
> nice if you could get the 256-color mode to "work" (or emulate it in
> some fashion). I'm not if any of the adapters do this (versus just
> running the actual composite output or something)?
>
> Also - you may want to adjust things, if you can, to allow for the 225
> line mode; not super-critical, as I don't know if there is much that
> uses it.
>
> How about the other "usable" modes? The CoCo 3 has a few other modes
> that can be dropped into, but aren't supported by BASIC - POKEs can get
> you into them, but really for anything reasonable you need ML. I think
> only a couple of them are actually usable for anything (IIRC, they are
> both a 160x192x16 color mode, and a 256x192x16 color mode; there also
> may be 4 and 2 color modes for each, I forget); I think they are
> mentioned in the service manual, and are also really detailed in some
> memory maps floating out there (including one mode that is something
> like 320x"infinite" that scrolls vertically; I think one of the guys on
> this list or elsewhere did a sound visualizer with it).
>
> I take it that the SG modes all look ok (there's only a few on the CoCo 3)?
>
> Additional resources which may be of interest:
>
> https://github.com/hoglet67/RGBtoHDMI
> https://retrohackshack.com/product/rgbtohdmi/
>
> ---
>
> https://github.com/qbancoffee/coco_rgb_to_hdmi_adapter/tree/main (might
> be related to the above adapter, unsure)
>
> ---
>
> https://www.thingiverse.com/thing:5528298 (unfortunately, just an STL
> file, so modding it may or may not be easy?)
>
> ---
>
> Hope these help or inspire...
>
> Andrew L. Ayers
> Glendale, Arizona
> phoenixgarage.org
> github.com/andrew-ayers
>
> --
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>