Z80 PLCC-44 to DIP-40 Adaptor for my In-Circuit Debugger Project

[Ed Silky]

I've mentioned my Z80 In-circuit Debugger (ZID) project a few times and it is making great progress. I plan to post details when I have the initial boards running, but I thought I would post this little part of it, as it was a big pain point that had to be solved.

My ZID board will use a 20MHz Z80 in a PLCC-44 pin package. However, to do the hardware and debugger software debugging, I need (at least really want) to plug in my current in-circuit debugger. This presents a problem, as my in-circuit debugger is for a 40-pin DIP footprint Z80.

So... I created an adaptor:

Here is how I went about creating it:

1. I designed and 3D printed a 'CUP' that could hold the array of 44 pins:

Cut 40 26AWG wires:

Stripped the wires, pushed them into 6*6 and 2*4 socket pin strips, and soldered each one:

Once soldered, the insulation was pushed down to the strip:

The strips were put into the correct locations in the cup and the cup was filled with epoxy: (no photo for that step - sorry)

Each wire got a piece of heat-shrink, and a small JST female connector pin:

 

Each one was then pushed onto the correct Z80 DIP-40 pin on the ZIF socket and soldered in place:

The heat-shrink was worked down over each pin and shrunk:

When I'm not needing to debug, a PLCC-44 socket plugs into the socket pins (on the finished PCB) and a 20MHz PLCC Z80 goes into the socket.

When I'm debugging with the adapter, I'll probably put a slower oscillator in the board, since the jumble of adaptor wires might not provide the cleanest signals at 20MHz, but we'll see.

-Ed