[Coco] 6809 vs 6309

[Darren A]

On 9/10/08, Bob Devries <devries.bob at gmail.com> wrote:
> Tony asked:
>>
>> Has anyone here tried replacing a 6809 with a 6309 in a device OTHER than
>> a
>> COCO ?
>
> No, but it should not present any problem, since the 6309 is pin compatible
> with the 6809 and the instructions are the same except in native mode.
>


As long as the software uses instructions that are documented as legal
6809 code, then there shouldn't be any problem. If it depends on
undocumented behavior (such as using an invalid register encoding in a
TFR instruction to load a register with FF or FFFF) then it would
likely have problems on a 6309.