Re: Installing GS RAM card in slots 1-7

[Alex Freed <alex_news@mirrow.com>]

> To maybe answer my own question:  I suppose the CB card is picking 
> up the writes that a program is making to the video memory and using 
> that to generate the VGA output.  If that is the case then I needn't 
> be concerned with the concurrent accesses to AUX memory and main 
> memory.

Correct. The CB card has its own memory and very fast one at that. And wide.
All the video data written by the 6502 appears on the same bus and goes 
into the odd and even banks depending on the soft switches that the CB 
also understands.

So displaying DHR graphics by CB is not too difficult - the basic timing 
is mostly the same as the 80 col text mode. The reason I didn't 
implement it was that I didn't have time to implement the color mapping.
Not trivial if one wants to mimic the artifacts, etc.
Wanted to do it later but had too much real work to do.

-Alex.

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