Thanks for the quick reply Jack. The sad thing is I'd watched all those videos you point to, and knew about writing circuits, and stll didn't get it. The last thing I tried last night was basically starting from a blank ZPUino circuit and adding the 7seg wishbone peripheral, then copied/pasted your example code just changing the wishbone slot to the one I'd used. Writing the circuit and uploading the sketch worked so I think I'm getting there. Something else that is still very confusing is the mass of wings, megawings, and shields. If an example uses a VGA or sound wing, say, I have no idea how to adapt it to use my logic megawing or the computing shield I have for the DUO. Do I edit the circuit and replace the stuff on the right-hand-side with the logic megawing or computing shield footprint (as appropriate) and remake the connections or something? Also, to be sure I get the relationship with DesignLab - DesignLab sketches can only be used if the ZPUino soft processor is in the FPGA, because that is what the compiled code runs on and the sketch uploader communicates with, right? To use something without the ZPUino I need to work in the Xilinx tools and not use any c++ sketch code. Anyway, the Papilio stuff is very cool, nice job. Regards, David.