[Coco] Kips 6809 SBC

Dave Philipsen dave at davebiz.com
Fri Oct 2 15:48:02 EDT 2015


Now there's a guy who knows his stuff!

Dave


On 2015-10-02 14:36, Gene Heskett wrote:
> On Friday 02 October 2015 13:12:02 Louis Ciotti wrote:
> 
> Teacher mode on.
> 
> Looks possibly ok, but to this old scope trace observer who has had a
> scope probe in one hand since 1951, your probe's ground lead is too
> long, so the scope if quite likely fibbing to you.
> 
> The ringing on the low logic probably isn't really there, but in your
> test setup.  I also suspect you had a ground clip with an 8" or so lead
> connected on the upper traces probe, but no grounding clip was 
> connected
> on the second probe showing the lower, blue trace.
> 
> Don't give a scope a chance to lie to you, that ringing on the lower
> trace could occasionally be seen as noise on the other side of a ttl
> inverter.  Unless your breadboard layout is pretty sloppy, I'd have 
> real
> serious doubts it really looks that bad.
> 
>> I also tied D2 and D5 high, and the Address likes are counting.  I
>> need to move it to a larger board and find my stash of LEDs and get
>> those hooked up, and I will attempt to make a video.
>> 
>> I did not do anything with the reset line.
> 
> It seems that you are succeeding, please carry on.
> 
> Cheers, Gene Heskett
> --
> "There are four boxes to be used in defense of liberty:
>  soap, ballot, jury, and ammo. Please use in that order."
> -Ed Howdershelt (Author)
> Genes Web page <http://geneslinuxbox.net:6309/gene>


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