Earliest listed revision, 0A, of the MSI MS-6501 motherboard, packed as a 1.40 MB ZIP. It is larger than the other MS-6501 archives, which may mean extra pages or files, but the name does not describe the contents. The likely payload is a schematic for tracing rails, checking the regulator circuits and locating components around faults. MSI uses MS-65xx numbering for its in-house desktop boards. Make sure your PCB is marked 0A, since prototype-stage revisions can differ noticeably from production units.
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 .zip file
Compressed archive that every operating system opens without extra software.