[Coco] 80 column pak prototype

[Gene Heskett]

On Wednesday 23 October 2013 14:06:56 Mark Marlette did opine:

> Luis,
> 
> Fun stuff!
> 
> On the note of strange characters. As it appears that these proto-boards
> are a good thing, they are not good for digital design at MHZ rates.
> 
> The CoCo's address bus is not buffered, unless you have a Pro-Tector+,
> so just driving through the ribbon cable to your board will be
> degraded. My tests shown ~3-4" was max, YMMV.
> 
> The proto-board adds capacitance to every point, some cases that is
> good, most cases it is not.
> 
> So your circuit can be wired electrically correct and it still will not
> work just by how you physically built it. That is not to say you don't
> have a wiring issue. :)
> 
> Generally it is cheaper and will yeild better results to have a board
> made.
> 
> My $0.02.
> 
> Any case, enjoy and continue your great work on the software and
> hardware!
> 
> Regards,
> 
> Mark
> http://www.cloud9tech.com 

And I'll throw in another 2 cents, Mark.  This board is dependent on the 
single ground pin in the socket connector.  It is not a very good ground.

I'd at least try adding another wire from the ground bus on the board back 
to one of the clips that grab the grounding ears of most boards, one on 
each side of the socket proper. 

> ________________________________
>  From: Luis Antoniosi (CoCoDemus) <retrocanada76 at gmail.com>
> To: CoCoList for Color Computer Enthusiasts <coco at maltedmedia.com>
> Sent: Wednesday, October 23, 2013 6:52 AM
> Subject: [Coco] 80 column pak prototype
> 
> 
> Hi all,
> 
> Having all the components at hand I started prototyping yesterday:
> 
> pic.twitter.com/aAnpm39NwL <http://t.co/aAnpm39NwL>
> 
> One hour later:
> 
> pic.twitter.com/dOEpz5Y91K <http://t.co/dOEpz5Y91K>
> 
> And turning this thing on:
> 
> pic.twitter.com/rl4fNtssfa <http://t.co/rl4fNtssfa>
> 
> You can see some characters are strange, I must have swapped a bit in
> the data bus or something. It was too late yesterday to troubeshooting
> but HEY IT WORKS!
> 
> Those protoboard jumpers are really helpful. :)


Cheers, Gene
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