[Coco] Color Computer 3 (and ethernet) prototypes...

[jdaggett at gate.net]

Al

If none of the jumpers have been distrubed and any wiring, the on ly concerns 
would be the the electrolytic caps. 

Best way to reform them is to bring the board power up very slowly and current limit 
the power supply. 

The ICs should have no problems sitting that long. 

Would love to have some time to reverse engineer that board. Like John stated, it 
does look as if they used some discrete chips to emmulate the GIME chip function. 
Many of the registers can be done with latches and even the MMU can be done 
discrete. It is possible that the circuit on board is the GIME in discrete form. It was 
typical of that era to do your chip in discrete logic first to verify functionality against 
and for design concepts when you received working parts. 

I would love to get a set of high resolution tiff format photographs that clearly 
display the chip id # or at least a parts list to see what chips are being used. Dang I 
wished I could make it this April to Chicago :-(((

That board has so many jumpers on it to correct the original layout will really make 
reverse engineering a hair pulling experience.

james


On 18 Jan 2005 at 9:17, alsplace at pobox.com wrote:

Date sent:      	Tue, 18 Jan 2005 09:17:02 -0800
From:           	<alsplace at pobox.com>
Subject:        	Re: [Coco] Color Computer 3 (and ethernet) prototypes...
To:             	coco at maltedmedia.com
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> John ... yes, I have access to the board, but I do not want to get
> power to it and risk frying something.  Ideally I'd like to get it to
> Mark Marlette and let him give it a hardware onceover and see if it
> works.  These boards probably haven't had any reason to be powered up
> in 20 years.
> 
> I will do what I can to make sure we can get some knowledge from
> these.
> 
>      -- Allen
> 
> 
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