Apple MacBook Air 4,2 boot ROM, version 0077 B12, for logic board 820-3023. Apple numbers its logic boards 820-xxxx, with a suffix letter for the revision. The 3.73 MB zip suits reprogramming the EFI SPI chip with an external programmer after corruption or a firmware lock problem. Older Mac dumps can carry serial number and system data from the donor machine. Back up the original chip first and transfer the unique data where needed before you flash.
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 | 30 Jan 2019 | Open file on RM Schematics |
| @IT_SERVICE_WORLD | 28 Oct 2019 | Open file on RM Schematics |
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 →