Small firmware archive, 423 KB in RAR format, labelled only P28 PDC, which gives no brand, board number or revision to go on. The P28 code may refer to a model or project, but that cannot be confirmed from the name, so identify the target by examining the contents and image size first. Dumps of this sort are written to a flash chip with an external programmer during recovery of a dead board. Read and keep the original chip contents and make sure the file matches the chip size.
The button opens the matching file on RM Schematics, or a source page if it is not catalogued there yet. The original attachment is from @biosarchive. Enginerys does not host this file.
How to open a .rar file
Compressed archive — the usual wrapper for a schematic + boardview pair or a BIOS + EC set.
Back up your own chip before writing any dump, and match the full board number and revision. Flashing guide →