[Coco] 4 Port MPI PCB artwork (so far)

RETRO Innovations go4retro at go4retro.com
Wed Mar 4 02:20:28 EST 2015


On 3/3/2015 3:50 AM, Gene Heskett wrote:
> Thats looking closer Jim. Change the leds to horizontal mounts so they
> shine straight down, & out from under the cart,
I just moved them over.
> add the gnd, 5v, +12
> and -12 connections for psu and it should be about ready to test.
Added
> How
> about a 4 wide dip switch to set the powerup default slot?
I put the proper slide switch
Here is the update: http://s6.postimg.org/g0u1mwfep/PCB1_2.png

  * 3V3 regulator added
  * slide switch added
  * standoff holes added
  * 5 pin DIN added, to use this PSU
    (http://www.jameco.com/1/1/27755-p25a13d-r1b-3-wire-ac-input-regulated-ac-dc-switching-triple-output-table-top-power-supply.html
    , though any source for P25A13D-R1B will work)
  * Mini USB added
  * All lines routed
  * All power caps added

Now, it's time to consider the size of the PCB.  There is some fat that 
could potentially be trimmed on the side, and a bit on the other side.  
Something to consider.

I came up with a potential idea for a cheap 8 slot unit, using the last 
remaining IO pin on the CPLD and the fact that I will probably use IDE 
cables for the cabling.  It might be possible to "daisy chain" 2 4 port 
MPI main units, and just set a jumper on one to be the "second 4", or 
"slave" if you like IDE parlance. Something I am kicking around, as it 
would not require building a new PCB, just repurposing the existing one.

Jim





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