Apple EFI firmware for logic board 820-3208 revision A, provided as an 8.00 MB .bin file. Beyond the board number and revision, the name gives no EMC number or working status. Use it to reprogram the SPI flash chip with a CH341A, RT809H or similar tool when the Mac fails to start because of damaged firmware. Match the 820 number on the PCB, keep a copy of the original chip read, and verify the chip size before writing the image.
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 @efibios. 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 →