Now that I've socketed the CPU and other custom ICs, I can fit the adapter I've constructed. The idea of this is to bring out all the CPU signals to a convenient header in order to avoid the frequent need to solder jumpers to legs of the CPU:

I wanted to use pins on the header, but since the daughterboard which will plug into the top of the adapter is also single-sided veroboard, it's easier to use sockets.

The jumpers attached to the adapter are for the 1MB SIMM upgrade. It's already a lot neater than it used to be...

Once everything is working, I'll construct an ARC Clock which will plug into the adapter, requiring only two jumper leads to the IOR/W lines on the IntSDX board.