[Coco] First impression of Roy's adapter.

[Mark McDougall]

Jim Cox wrote:

> I just posted a page on my site that has pictures of
> Roy's CoCo VGA Adapter.

Your screenshot brings up an interesting question...

I'm currently implementing the CoCo 1 in an FPGA. More specifically, I'm 
currently working on the 6847, having it generate composite and VGA 
output at the same time. I'm using 640x480 mode for VGA and because (my) 
horizontal timings are exactly twice the frequency of the composite 
signal, the borders in this mode are quite significant. I notice they 
are on the adapter as well!

Is the adapter using 640x80 mode (timings and sync polarity at least)?

Also, it's been many years since I let my Coco go and have seen a real 
CoCo running - are the borders on composite output as significant as 
they appear in the VGA screenshot?

Regards,
Mark