A BIOS / firmware dump for Apple hardware (board 820-2179). Shared as “Apple iMac 27- Late 2013_A1237_820-2179-C.bin.zip” — a .zip file, 1.72 MB.
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 @Laptopbiossolutions. Enginerys does not host this file.
How to open a .zip file
Compressed archive that every operating system opens without extra software.
Built-in OS tools7-Zip
Back up your own chip before writing any dump, and match the full board number and revision. Flashing guide →