BIOS / EFI firmware for the Apple MacBook Air A1466 on logic board 820-00165-A, supplied as a 4.21 MB zip. Apple boards use the 820-xxxxx numbering with a revision letter suffix, and many A1466 boards share the model number but not the firmware. Technicians flash this image to the SPI ROM with a programmer to cure boot loops, no chime or a locked firmware. Read the original chip first to preserve the serial number and other system data, and check the chip capacity matches 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 @biosarchive. Enginerys does not host this file.
How to open a .zip file
Compressed archive that every operating system opens without extra software.
Back up your own chip before writing any dump, and match the full board number and revision. Flashing guide →