On the pa80 forum over at IrishActs, there has been details regarding Musictronics progress is adapting its proprietary USB hardware to the pa80. It is available, but the developer, Oliver Schwartz, still can not figure out how to avoid one problem. You must reboot (turn off, turn on) the pa80 keyboard after each and every disk management operation for the changes to show up in the pa80. At least that's how I understand it. Hopefully, this problem will be overcome.
The USB interface is not available for the PSR2000. If it was, Oliver would sell a lot of them!
Tom G.