[Coco] Coco compatible monitors...

[John Kent]

On 6/07/2011 11:37 PM, Mark McDougall wrote:
>
> <http://en.wikipedia.org/wiki/TRS-80_Color_Computer#Artifact_colors>
>
> If you're running your Coco implementation at native speed, there 
> should be plenty of bandwidth to interleave access to video memory by 
> a 'filter' that attempts to produce some form of artifacting, without 
> having to steal CPU cycles.
>
> Alternatively, you can use a line buffer and produce the effects 
> on-the-fly without requiring extra bandwidth. However, indications are 
> that adjacent lines combine to affect one-another, so one line 
> wouldn't be sufficient. You'd have to buffer several lines.
>
> I did see somewhere in a software emulator an approximation of the 
> artifacting... from memory it used a rather complex (and large) 
> matrix, though IIRC it was empirically derived rather than based on 
> any theory of the cause in a real Coco.
>
> Regards,
>
Goodo
You could use some sort of 2 x 2 pixel look up table although it's 
dependent on the position of the pixel relative to the color burst so 
you might need the horizontal synch pulse too.

Night folks

John

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