Apple all-in-one firmware for model M78, logic board 820-2110-A, described as an HBM 2 MB BIOS image inside a 1.27 MB RAR archive. Apple identifies its logic boards with 820-xxxx part numbers followed by a revision letter, which should be confirmed on the PCB before flashing. The dump is intended for restoring the boot ROM with an SPI programmer; save a copy of the existing chip first and verify the image size matches the 2 MB flash so it writes cleanly.
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.
All sources (2)
The same file was posted more than once. If one link is dead, try the next.
| Channel | Posted | |
|---|---|---|
| @biosarchive | 16 Mar 2024 | Open file on RM Schematics |
| @generalbios | 14 Jul 2024 | Open file on RM Schematics |
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 →