[Coco] Any reason to put a 6309 in a Coco2?

[jdaggett at gate.net]

John 

Unless you are writing machine language programs that uses the chip in Hitachi
mode, its increased registers and instructin set, then no there is no real
advantage in a CoCo2 or even a Coco3. It is like having two processors in one. 

In Motorola mode the chip looks, acts, and runs like a MC68x09E. 

The HD63x09E makes it presence felt when you use a Coco3 and the versions of 
OS9
that take advantage of the increased registers and instructions that Hitachi put
in.

As for the Coco3 is 99.9% backward compatible. Only Semigarphics S4 is 
supported. Semigraphics S8,S12, and S24 are not. THe GIME chip does not fully
implement all the SAM functions. They are not totally lost but are done better
in the newer higher resolution graphics capability of the Coco3. Outside that
all your Coco standard off the shelf software should run normally. Your own
personal software may need tailoring if you use any of the unsupported
semigarphic modes.



james


On 30 Dec 2003 at 8:39, John Guin wrote:

>  Hello all,
> 
> My wife got me a 6309 for Christmas, and I am itching to install it.
> However, I can't think of a reason to put it in a Coco2, which is all
> I have available at the moment.
> 
> So can anyone think of a reason to install it in a Coco2?
> 
> And a related question:  was the Coco3 100% Coco2 compatible?  Was
> there anything (at all) a Coco 1 or 2 could do which a Coco3 could
> not?  It seems to me if the answer to this question is no, there is
> nothing a Coco2 can do which a Coco3 can not, then there is no reason
> to install the chip in a Coco2.
> 
> Thanks,
> John Guin
> 
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