A schematic diagram (board 10215-1). Shared as “INTEL Quad-Core DG15 10215-1 10215 PDF .rar” — a .rar file, 1.58 MB.
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 @generalbios. 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.
7-ZipWinRARThe Unarchiver (macOS)