[Coco] MC6847 VGA Board Project (non-FPGA)

[Kip Koon]

Hi Ed,
Very nice indeed!  I will be interested in this board eventually as well as some others you have.  :)  

Kip Koon
computerdoc at sc.rr.com
http://www.cocopedia.com/wiki/index.php/Kip_Koon


> -----Original Message-----
> From: Coco [mailto:coco-bounces at maltedmedia.com] On Behalf Of Zippster
> Sent: Sunday, June 07, 2015 12:50 AM
> To: CoCoList for Color Computer Enthusiasts
> Subject: [Coco] MC6847 VGA Board Project (non-FPGA)
> 
> Hello everyone,
> 
> I’ve posted a bit about this on the Facebook group, but I know not everyone from the mailing list uses it.
> 
> Thought I’d share a little bit about a MC6847 to VGA project I’ve been working on.
> 
> The theory is that the board uses comparators configured as a ADC on the component video outputs from the MC6847 to break the
> signals down.  From there a CPLD is configured to convert this output into digital RGB.
> This in turn is run through an Analog Devices Video DAC where the video is output in analog RGB at VGA scan rates, using a new pixel
> clock generated by the onboard clock circuit (per Analog’s data sheet specs).
> 
> I fully expect there will be some debugging, but I think it’s looking pretty good so far.
> 
> Here are a couple of pics of the board layout, and a (mostly) assembled prototype.
> I didn’t have a particular cap value on hand, so prototype testing will be after my next shipment of parts from Mouser.  Hopefully it
> goes well.  :)
> 
> Layout <https://drive.google.com/open?id=0B1sgl615FlGnQzdwTFJsNTRKLWM&authuser=0
> <https://drive.google.com/open?id=0B1sgl615FlGnQzdwTFJsNTRKLWM&authuser=0>>
> PCB <https://drive.google.com/open?id=0B1sgl615FlGnYjdzNEpGSnZiWm8&authuser=0
> <https://drive.google.com/open?id=0B1sgl615FlGnYjdzNEpGSnZiWm8&authuser=0>>
> Populated (mostly) <https://drive.google.com/open?id=0B1sgl615FlGnME4tYU1EdzdDQTQ&authuser=0
> <https://drive.google.com/open?id=0B1sgl615FlGnME4tYU1EdzdDQTQ&authuser=0>>
> 
> 
> - Ed
> 
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