PRC (Palm OS)
PRC (Palm Resource Code) is a container format for code databases in Palm OS, Garnet OS and Access Linux Platform. Its structure is similar to PDB databases. Usually, a PRC file is a flat representation of a Palm OS application that is stored as forked database[clarification needed] on the PDA.
PRC files are also used by the Mobipocket e-book-reader (here sometimes referred to as MOBI format). The AZW format of Amazon's Kindle reading device is in turn a DRM-restricted form of the Mobipocket format.
On Palm OS, PRC files are used for applications, localized resources (overlays) and shared libraries.
Structure of PRC file
|PRC Resource Header|
The PRC header is located at the beginning of the file and contains meta-information on the file:
|0x24||creation time||MAC OS 9 time - 32bit unsigned integer - number of seconds since midnight, January 1, 1904 GMT||4 Bytes|
|0x28||modification time||MAC OS 9 time - 32bit unsigned integer - number of seconds since midnight, January 1, 1904 GMT||4 Bytes|
|0x2c||backup time||MAC OS 9 time - 32bit unsigned integer - number of seconds since midnight, January 1, 1904 GMT||4 Bytes|
PRC Resource Header
For every resource (specified by num_records), there is a resource header containing:
|name||char||Name of the resource||4 bytes|
|ID||integer||ID number of the resource||2 bytes|
|offset||integer||Pointer to resource data||4 bytes|
Every application contains al least a Code #0 resource with size information and jump tables, a Code #1 resource with executable code and data resources containing pre-initialized values of global variables in compressed form. Other resources that may be contained are forms, form objects, alerts and multimedia data, e. g. images and sounds.