Tested BIOS dump for the Apple A1311 iMac, logic board 820-2784, with the name also carrying the K74 project code and the 051-8337 schematic number. The RAR archive, 1.67 MB, holds the EFI firmware image intended for the board SPI flash. Technicians use it to recover a machine with corrupted boot ROM by writing it with an external programmer. Confirm the 820 number on the PCB first, read and save the original chip contents, and note that serial and system data may need to be transferred into the image.
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 (5)
The same file was posted more than once. If one link is dead, try the next.
| Channel | Posted | |
|---|---|---|
| @biosarchive | 5 Sept 2023 | Open file on RM Schematics |
| @generalbios | 12 Oct 2023 | Open file on RM Schematics |
| @generalbios | 15 Oct 2023 | Open file on RM Schematics |
| @generalbios | 19 Oct 2023 | Open file on RM Schematics |
| @generalbios | 26 Oct 2023 | 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 →