re: EV-100 power on board

[Prof Bill Neill <ev3bill@yahoo.com>]

Thank you for your comment. Please continue to argue your position and
follow up with more comments.

--- Jim Phillips <james-phillips@uiowa.edu> wrote:
> I don't have much to say on the matter, but..  There
> are reasons to
> group all of the power pins together.  First, if you
> use single or
> double sided boards (not ground planes) then grouping
> them together
> allows you to filter them properly and simply with
> capacitors.  Second,
> routing, say power on one end and ground on the
> other, forces the power
> currents to form a loop which increases EMI and noise
> over having them
> close.  I would also recommend grouping pins across
> from each other as
> the same voltage, it simplifies the backplane design.
>  Four pins mught
> be better for ground, too. 
> 
> Jim
> 
> Prof Bill Neill wrote:
> > 
> > EV-100 Board Power STANDARD
> > Everybody join in and help us decide which pins
> will provide power and
> > common on the EV-100
> > SYSTEM BUS.
> > Below is a S-100 card from the old computer. We can
> change the size
> > and
> > shape of our EV-100
> > cards, still using the 100 pin connector. If we
> stay with a STANDARD
> > SIZE everything will cost
> > less.
> > 
> > <----------10
> inches------------------------------------------------->
> >
>
+--------------------------------------------------------------------+
> > |       EV-100 board layout for +12 Volt Power and
> Common            |
> > |       STANDARDIZES EV-100-PINS 10 AND 40         
>                  |
> > |                                                  
>                  |
> > |                  ______________________________  
>                  |
> > |                 |                             |  
>                  |
> > |                 |       POWER LOOP            |  
>                  |
> > |                 |                             |  
>                  |
> > |                 |                             |  
>                  |
> > |                 |                             |  
>                  |
> > |                 |                             |  
>                  |
> > |                 |                             |  
>                  |
> > |                 |                             |  
>                  |
> > |                 |                             |  
>                  |
> > +--------         1         2         3         4  
>       5----------+
> >         
> 12345678901234567890123456789012345678901234567890
> >         
> ||||||||||||||||||||||||||||||||||||||||||||||||||
> > Connector is 5.5
> inches----------------------------------->
> > Card is 6.5 inches tall.
> > 
> > Place power on pins 10 and 40.
> >
> 
> 

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