PRC

From MobileRead

All files synced to RAM on a PalmOS device must be in Palm Database Format. PRC files are Palm Resource Compiler files, which are a type of Palm Database containing "resources". In actual fact files synced in RAM are not files at all as there is no file system in RAM on a PalmOS system thus no need for extensions or other file designators.

All programs on a PalmOS device are PRC databases, with the resources being the actual program code. However, all PRC databases are not programs. It is possible for data files to be PRC databases, and products like the MobiPocket reader for PalmOS keep documents in PRC format. For more information see PDB (Palm DataBase). The file types only become important when the data is synced back to a host computer for backup storage.

Some eBook readers try to distinguish their eBook format from other database files. In particular MobiPocket and Palm eReader do this. This is because only two extensions, PRC and PDB, are accepted for storage in the device. The file extensions can be renamed without a problem on the device and MobiPocket, in particular uses a different extension, .mobi for files on a PC. This extension can also be used on files stored on a SD card even when the card is used on a Palm device.

For more information on the PRC file format consult http://web.mit.edu/tytso/www/pilot/prc-format.html