Duplicate copy of the Apple 820-00165-A firmware labelled G944 0166_B02 Clear me, zipped at 4.14 MB, with a (1) suffix typical of a second saved copy. It covers the same logic board and appears to be the same cleaned boot ROM image. Compare checksums with the other copy to confirm they match before use. Write it to the SPI flash with a programmer only after saving the original chip contents, and verify the board number on the PCB first.
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 @SCHEMATICWORLD. 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 →