Firmware for an Apple MacBook model A1278 on logic board 820-3115, revision B, marked as working (OK). Apple uses the 820-xxxx pattern for logic board part numbers. The RAR holds a BIN for the SPI boot ROM, which technicians reprogram to fix no-boot faults or firmware lock issues. Read and save the original ROM first, since it holds the serial number and other unit-specific data, and confirm the board number and revision on the PCB.
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 @hrtechno. 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 →