Recently I got an inquiry from a user of the NLS digital DAISY player - the Library of Congress player. The user had encountered a "cartridge error" message while playing our DAISY digest and was asking if we knew what that meant.
Well, I didn't know, so I went to Google and found a helpful FAQ, Frequently Asked Questions, on The National Library Service website. Here is the link, where you can find the answer to the mysterious "cartridge error" message and lots of other good stuff:
Patrick Tice, WA0TDA