BIOS dump for an Apple MacBook Pro A1278 on logic board 820-3115, revision B, with the name also noting BION. Packed in a 3.91 MB RAR, it is meant for reprogramming the EFI firmware SPI chip when the machine shows no chime, no boot or a firmware lock issue. 820- numbers are Apple's logic board part numbering, printed on the PCB. Confirm the board number, back up the original chip since it contains serial and model-specific data, and verify the image matches the flash chip size.
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 @biosarchive. 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.
Back up your own chip before writing any dump, and match the full board number and revision. Flashing guide →