Boardview for the Apple logic board 820-2060, marked BDV in the name and packed in an 80.1 KB RAR file. The revision letter is not included, so verify the full number on the PCB. After extraction, open it in a boardview program such as OpenBoardView or FlexBV to view component placement and net connections. It helps locate test points, check what sits on a shorted rail, identify connector pins and find parts referenced in the matching schematic.
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 @cyberlanelectonik. 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)