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

[Theodore Evans (Alex)]

On Dec 31, 2003, at 4:51 AM, Torsten Dittel wrote:

>> The GIME chip is the Coco3 will not support semigraphic modes
>
> When I was talking about the "3" I referred to the "6309", not the
> CoCo3. Sorry for the confusion. I wondered if a 6309 running in
> 6809-mode would be fully compatible to an "original" 6809.

As compatible as is possible without being identical.  All useful 
instructions on the 6809 work exactly the same way on the 6309 
including the number of cycles required to execute them.  It is 
possible, but unlikely that there is some code out there that uses one 
of the new instructions as a nop and would as a result react in a 
different fashion.