[Coco] Kip's Single Board Computer

[RETRO Innovations]

On 9/7/2015 10:22 AM, Darren A wrote:
> On Mon, Sep 7, 2015 at 12:18 AM, RETRO Innovations wrote:
>
>> Kip, working on debugging your 8 IC SBC, and I have a question:
>>
>>   * The CPU on this board is a 62C09P, which it appears will run up to
>>     3MHz, but you've installed a 7.37MH Crystal on the board. Was that
>>     by design?  Am I missing something (like the 6309/6809 divides the
>>     clock by some value?)
>>
>> Otherwise, I think this SBC is not going to work unless we put a slower
>> crystal in the design.
>>
>
>
> The 6309 works just like the 6809 (non-E versions). They divide the
> frequency on the EXTAL pin by four to get the bus frequency (E and Q).
>
> - Darren
>
Thanks.  Figured it out this morning when I woke up (duh, how else to 
get the quadrature timing), but something is wrong with the PCB. I 
pulled a 6809 from a SuperPET and both 63C09 and 6809 are not 
oscillating on the EXTAL/XTAL pins, and no E or Q is present.  I pulled 
the CPU and put it on a breadboard without change.  My Coco3 CPU is 
soldered in, or I would swap them out to check, but I find it odd that 
two CPUs are bad.  !HALT is high, as is reset, so I should be seeing Q 
and E on my scope.

It's a bummer, as I have a 80 channel Logic Analyzer here just waiting 
to see signals from the '09

Jim

-- 
RETRO Innovations, Contemporary Gear for Classic Systems
www.go4retro.com
store.go4retro.com