Raw 8MB firmware image for an Apple logic board numbered 820-00281, revision A, saved as a plain BIN file. Apple uses the 820-xxxxx scheme for its logic boards, so the number etched on the PCB should match before you flash. An 8MB size points to a full SPI ROM dump that includes the EFI firmware and NVRAM areas. Write it with an external programmer, but read and back up the existing chip first, since its serial and machine-specific data may differ from the donor dump.
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 →