Originally Posted by wallcraft
If the PRC has Mobipocket DRM (i.e. is encrypted) then you need to first strip the DRM. See Mobipocket Decoder Tool
. Once DRM-free, ABC Amber Palm Converter might work but I would use Calibre's mobi2oeb command line utility to convert it to HTML and then use whatever (perhaps OpenOffice) to go to PDF.
Where does one get Mobipocket decoder tool and mobi2oeb?