ZIP archive for revision 0B of the MSI MS-6502 board, about 1.07 MB. The name does not list the contents; a PDF schematic is the typical payload for this kind of file. MSI uses MS-65xx numbers for its own desktop motherboards. Opened with any ZIP utility, the pages help with tracing VRM phases, memory voltage and the chipset supply, and with locating parts around a short to ground. Check that the PCB silkscreen reads revision 0B, since component values may change between revisions.
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.