[Coco] CC-Five (was Re: Pseudo CoCo4???) (LONG)

[Joel Ewy]

Mark McDougall wrote:
> Joel Ewy wrote:
>
>   
>> 1.  Does the CoCo care what kind of microcontroller is in the S/S Pak as
>> long as it does its job in the expected manner?  I wonder if one could
>> sub a PIC core (or maybe a 68-something) and then also make it a more
>> general-purpose I/O processor.  
>>     
>
> Probably not, so you could in theory use a different uC, but you'd have to 
> port the ROM software. I think it's better to stick with the original 
> architecture.
>   
That's a good point.  I don't have a good feel for what the uC in the
SSC is doing, so I don't really know how complicated its programming is
likely to be.  If it's just shuffling data around in response to
instructions from the CoCo, then I would think it would be easier to
reimplement its functionality in an existing uC core than to try to
reverse engineer an obscure microcontroller.  But if it is doing all
kinds of inscrutable audio magic then the latter might be easier.  I was
just imagining it being an I/O controller black box with easily
replicable and well defined functions.  But that's all just based on
what little I've read about it on this list in the last few days.
> In an FPGA you can run any number of uP cores (space permitting), so I don't 
> see much advantage in multiplexing either the 6809 or the S/S Pak uP...
>   
Right.  It's just that "space permitting" part that I, with my
not-especially-detailed understanding of current FPGAs was worried
about.  Because I'd really like to see some unclaimed logic real estate
that could be used for special processing units that could be swapped in
and out.  And I guess I just figured that if you're going to stick a
microcontroller in there, you might as well get as much work out of it
as you can.  Have any idea about what percentage of likely FPGA
candidates would be consumed by something like an off-the-shelf PIC core?
>> 2.  How hard would it be to combine the Orch-90CC and the Speech/Sound
>> Pak?  I'm not real clear on how the S/S Pak is set up, or where the
>> dividing line is between analog and digital on it.  But surely an
>> amplifier is common to both, though the S/S Pak is perhaps just mono? 
>> Putting a stereo amp in the external hardware would just make sense. 
>>     
>
> That's the beauty of an FPGA. You can add both Orch90 and S/S Pak, and mix 
> them digitally internally to send to the one analogue output.
>
>   
Exactly!
> Regards,
>
>