Hi George,

For the MP-1 mod, I didn't use a custom PCB. It is generic stripboard. Of course, to put any dual-inline-pin IC onto stripboard, you have to cut the traces, or get a stripboard which is prepared for this use already.

It is very simple:

So you can see that the two resistors and disconnection of Pin 26 are due to diligent adherence to the data sheet; perhaps the chip can work without them.

Crude diagram: