Compressed archive named for the FIC PCA40D board, about 1017 KB, with no revision or contents stated. PCA40D is a First International Computer board code, with the D suffix denoting a variant within the PCA40 family. Packages like this usually contain a schematic, which can be extracted with 7-Zip or WinRAR and read as PDF. It helps with tracing power rails and locating components. Since the revision is unknown, compare the document title block with the markings printed on your board.
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 @IT_SERVICE_WORLD. 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.