Tormod's excellent uDW works best with a modified BASIC ROM containing a driver, otherwise it is necessary to load in a driver via other means.
With that in mind I've fitted an audio output to my uDW and added support to the firmware to play a special file from the SD card in a form that can be loaded with CLOADM via a cassette cable.
Updated firmware plus some details and photos can be found here: https://gitlab.com/sorchard001/udw-firmware