[Coco] Re: Color Computer 3 prototype

[jdaggett at gate.net]

Allen

I am still try ing to figure out what the TBP28S42 is being used for? 
a 512 by 8 TTL PROM. My first guess is a color pallette look up 
table. I have also found three other TTL PROMS on board. 

It looks as if they used TTL proms to control logic almost as a 
computer uses microcode to do an instrtuction. 

Except for the label covered ICs, I have deciphered functionality of 
the rest of th e ICs. I am in a mode now to figure out a kind of more 
detailed block diagram of what the GIME could look like. A bit more 
detailed than that in the Service manual.

james


On 21 Jan 2005 at 2:10, Allen Huffman wrote:

From:           	Allen Huffman <alsplace at pobox.com>
Subject:        	Re: [Coco] Re: Color Computer 3 prototype
Date sent:      	Fri, 21 Jan 2005 02:10:48 -0600
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<coco at maltedmedia.com>
Send reply to:  	CoCoList for Color Computer Enthusiasts 
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> 
> On Jan 21, 2005, at 12:14 AM, Nickolas Marentes wrote:
> 
> > The board looks bid but I would have thought that to construct the
> > GIME chip out of discrete components would take up another board
> > similar in size. Maybe they used a lot of programmable PAL's?
> 
> ...for those of you just joining us...  I really need to set up a list
> just for a few of us to disect this thing -- alot of great info has
> come to me via you, Mark M, and a few others -- and it would be nice
> to get everyone talking about it.
> 
> So far, it seems to use a bunch of PALs and contain a 1773.  WHO
> KNOWS! 
>   I'll take it home with me next week, most likely, or maybe tomorrow.
>    
> What can I do?
> 
>   -- Allen
> 
> 
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