Raw BIOS binary, 8 MB, labelled for an Apple MacBook Air 1466, presumably model A1466, and marked OK as a reported working dump. No logic board number or EFI version appears in the name, so confirm the 820- board number on your PCB is one that ships in that model before using it. The 8 MB size fits a 64 Mbit SPI flash chip. Read and save the original contents with a programmer first, because the original image carries the serial number and system configuration data.
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 @cidschematicandboardviewofficial. Enginerys does not host this file.
How to open a .bin file
A raw, byte-for-byte image of a flash chip: the main BIOS / UEFI, the embedded-controller (EC) firmware, or both.
Back up your own chip before writing any dump, and match the full board number and revision. Flashing guide →