From: David Salamon
Subject: Re: Expanding ISA slots in an A3000

Here is Jeff Wille's info on adding a third PC slot to your A3000.  

I have a couple of pointers. First, the XT or AT connectors from Radio Shack
(solder tail version) work well for this and they are cheap.

Second, I strongly recommend using a 64 pin "insulation displacement" 
edge card connector as your extra slot instead of another XT connector, 
since the edge card connector can just press onto the ribbon
cable and save you half of the soldering job.  Since the XT connector is
only 62 pins, you have a little space at the end on the 64 pin edge card
connector, but so what.

Good luck!

David

HOW TO ADD A 3RD INTERNAL IBM AT/XT SLOT TO YOUR AMIGA 3000 - Jeff Wille
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This describes how to build a connector that allows the lowest slot in the
A3000 to be used as an IBM AT or XT slot.  (BTW, I take no responsibility 
for you or your A3000 should you fry either one.  I've only done this for 
an XT slot, but an AT slot should be a straight-forward extension of these 
instructions.)

It's relatively easy, inexpensive (< $15 probably) and it shouldn't void 
your warranty since you don't have to make any changes to the computer 
itself.  Basically what you do is make a Y connector which plugs into the 
lowest IBM slot (which is the next-to-the-lowest slot).  The lowest slot 
is an Amiga slot and that's where you put your 3rd IBM board.  If you make 
it compact, you can still put the cover back on your A3000 with your boards 
plugged into it (unless you have very tall boards.) 

First you need a card-edge (with terminals) which will plug into the IBM 
slot.  What I did was get an old parallel interface board and cut off the 
part with the card-edge terminals with a hack saw.  If you want to make
an AT slot, get an AT style board (with two sets of terminals).  But then 
you knew that, right?   Make sure you get one that has nice solder pads 
on it.  It will make your life easier.  Next you will need two card-edge
connectors (4 for an AT slot).  I got mine from a dead AT motherboard, 
although I'm sure you could buy these parts new if you wanted to.  Connect
each terminal of the card edge to the corresponding contacts on the card-
edge connectors with a short (~1.5 inch) piece of ribbon cable.  In other 
words, hook everything up in parallel, pin 1 to pin 1 to pin 1, pin 2 to 
pin 2 to pin 2, etc.  That's basically it.  

To make it very compact you can bend the leads of one of the edge
connectors inward and solder them directly onto the card edge and only
run the ribbon cable to the second connector.

If your 3rd board consumes a lot of power, you will want to make the 
following additions suggested by Dave Haynie.  I had to do this to get my 
Data Acquision and Motion Controller boards to work reliably.  (It's
probably not a bad idea to do this in any case.)  Run heavier wire for
the +5V and GND connections.  Pins B1 and B31 are GND, and pins B3 and
B29 are +5V.  The B pins are on the solder side of the board.  Then put a
0.1 uF capacitor between B1 and B3, and another between B29 and B31.

IMPORTANT NOTE:  Once you are finished, make sure you test 
all of your connectors to make sure everything's hooked up right and
you haven't made any solder bridges.

Plug the card edge into the lowest IBM slot and plug two IBM boards into 
the card-edge connectors.  You will not be able to use the normal retaining 
screws to hold your boards in place and ground them, because the boards 
won't slide in all the way.  So, you can either put in a spacer (standoff)
and put a screw into that, or just run a grounding wire from the chassis
to the port cover (or whatever the metal end of the board is called).  

With this technique I am currently running an AT bridgeboard, a Data
Translation data acquisition board, and a Galil 3-axis servo motion
controller board simultaneously.  

Good luck.  
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Jeff Wille