Odd PalmOS .pdb file type?

[RMOP]

I have an OLD PalmOS application, namely the Oxford American Desk Dictionary and Thesaurus, published by HandMark (now defunct, AFAIK) in 2003. It consists of an Application file, Oxford DDT V1.04.prc (588kb), a Data file, OxfordText.pdb (5006kb) and a Serial Number. The .pdb extenstion suggests a standard PalmOS eBook such as are all of my MobiPocket eBooks on my old Palm T|X. But, that is not the case. The Application looks very much like MobiPocket, but isn't. Unless the Oxford DDT application is installed, the OxfordText can't be viewed. It installs to the SD card in the Launcher directory, but is invisible to the Palm MobiPocket reader.

Anyone know anything about this particular .pdb eBook format? I added it to Calibre, but it is not readable there (nor convertable). It appears to have some sort of DRM which prevents its being read anywhere outside of the associated application.

[Quoth]

No, .pdb is a generic PalmOS ending that originally meant Pilot Database.
There are at least two different .pdb formats that Calibre supports for ebooks.
One is the PalmDOC eBook format which is a special version of the PDB format

The last mobipocket for PalmOS reads both. Other programs read only one.
There are likely many other programs on PalmOS that use files with a .pdb ending.

See https://hwiegman.home.xs4all.nl/file.../P/pdb/pdb.htm
and https://en.wikipedia.org/wiki/PDB_(Palm_OS)
The .prc is also a kind of database file, the Palm Resource Code, see https://en.wikipedia.org/wiki/PRC_(Palm_OS)



There are also MS .pdb = Program Database on Windows NT and Protein data files that have nothing to do with Palm OS.

Palm started on 6800 and moved to ARM.

[RMOP]

Well, thank you. I'd wrongly assumed that the aforereferenced .pdb file was equivalent to the files used by the MobiPocket reader. Was really hoping that MobiPocket would be able to read this dictionary. But, good to know the reason it can't.