Apple MacBook Pro A1236 firmware image for logic board 820-2850, revision A as given in the name. The 4.00 MB binary matches a 32 Mbit SPI flash and holds the EFI boot ROM used by this generation of Apple notebooks. Technicians write it to the board flash with an external programmer when the machine will not chime or shows no video after a corrupted update. Compare the 820-2850 number silkscreened on the logic board first, read and save the original chip contents, and keep in mind that serial number and LAN MAC data may need restoring afterwards.
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 .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 →