@dc42 can you explain to me, as if to an idiot who hasn't read & internalised the detailed workings of the controller, the upgrade process?
You mention Duet firmware + DWC, as far as I'm aware there's only one board / controller...
I'm guessing the Duet firmware runs on the micro and is perhaps 'RepRapFirmware.bin' that I should somehow be putting on the board via one of the various processes described in the update page, but which one?
https://duet3d.dozuki.com/Wiki/Installing_and_Updating_Firmware
or
https://duet3d.dozuki.com/Wiki/Installing_and_Updating_Firmware_(Legacy)
and which part(s) of those?
Is the DWC just a web application served from SD card and updated via the web interface?