BIOS firmware for the Apple A1297, the 17-inch MacBook Pro, on logic board 820-2914-B, codename K92, stored as an 8 MB image in a RAR archive. Apple uses the 820-xxxx pattern for its logic board numbers, with the letter suffix marking the revision. The dump is meant for reprogramming the boot ROM when a board will not chime or boot due to corrupted firmware. Read and save the original chip first, since it holds serial and system data, and confirm the chip is 8 MB and the board number matches before writing.
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 .rar file
Compressed archive — the usual wrapper for a schematic + boardview pair or a BIOS + EC set.
Back up your own chip before writing any dump, and match the full board number and revision. Flashing guide →