PDB Converter

PDB (Palm Database) is a generic database container format created by Palm, Inc. for the Palm OS platform, first appearing with the original PalmPilot in March 1996. In the ebook context, PDB files most commonly use the PalmDOC or Plucker encoding to store readable text with basic formatting. The format consists of a 78-byte header identifying the database name, creation date, and record count, followed by a record index table and the data records themselves. PalmDOC-encoded PDB files use a simple LZ77-based compression scheme to pack plain text efficiently, while Plucker extends this with HTML rendering, image support, and hyperlink navigation. PDB ebooks powered a thriving mobile reading ecosystem years before dedicated e-readers existed — millions of Palm OS users carried entire libraries on devices like the Palm V, Tungsten, and Treo handhelds. A primary advantage is extreme simplicity: the flat record structure and minimal overhead mean PDB files parse instantly even on severely constrained hardware with limited memory and processing power. The open, well-documented structure is another strength, having spawned numerous reader applications across Palm OS, Windows, and later mobile platforms. Though the Palm platform is long discontinued, PDB ebooks remain accessible through conversion tools and readers like Calibre, and the format holds historical significance as one of the earliest practical mobile ebook solutions.