I've got a few backup sets (potentially incomplete) done on MicroRSX that were created with BRU on RX50 media. I've cranked out some code to itemize the contents, but the file types are a mystery. I suppose that one has to live in that world to know (e.g. MSL)
The sets appear to be (parts) of an incremental backup scheme; I think I've got at least one copy of the complete set. Would anyone be willing to have a look at the (ASCII) file catalog and suggest the application that may have created the files? Email me offlist if interested. --Chuck