Re: DD2 & 3

From: Jim Brain <>
Date: Tue, 18 Jun 2013 12:38:52 -0500
Message-ID: <>
On 6/18/2013 12:12 PM, wrote:
> For real reasons we would have to ask the creators themselves (I 
> haven't found them on facebook yet ;-) but my best guess is that they 
> wanted to be farsighted and less vulnerable to the whims of CBM than 
> they were with the original design. Therefore they might have asked 
> themselves the question "what if tomorrow Commodore takes more bits 
> out or something?" "It's quite unlikely that they get rid of 6502 
> though so let's depend only on this one" - my guesses and 
> speculations. Another thing is that they probably wanted the design to 
> be applicable to many target devices without redesigning. No matter 
> how laid out the controller's PCB is and whether there is a free port 
> (be it VIA or CIA or whatever else) or not
I guess, but dubious.  CBM could have just went and stuffed something in 
the address map that contradicted the 6821 address space.  IN any event, 
it was an academic question.  Interesting that they sourced a 6821 
instead of just adding a '574/'245 or something simple.


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Received on 2013-06-18 18:02:09

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