Boot ROM firmware for the Apple iMac 27-inch 5K Retina on logic board 820-00609-A, stored as a 4.25 MB RAR. The 820 prefix is Apple's logic board part number, with the final letter showing the revision. Technicians write such an image to the SPI flash with a programmer to revive a board that fails to start after corruption. Read and back up the existing chip first because it holds serial and system data, and check the size against the flash capacity.
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 (9)
The same file was posted more than once. If one link is dead, try the next.
| Channel | Posted | |
|---|---|---|
| @biosarchive | 20 Jun 2020 | Open file on RM Schematics |
| @biositechyangiyer | 24 Jun 2020 | Open file on RM Schematics |
| @biositechyangiyer | 28 Jun 2020 | Open file on RM Schematics |
| @laptexlaptopbios | 28 Jun 2020 | Open file on RM Schematics |
| @laptexlaptopbios | 6 Jul 2020 | Open file on RM Schematics |
| @one5technology | 21 Nov 2020 | Open file on RM Schematics |
| @biosdumpcomputer | 26 May 2022 | Open file on RM Schematics |
| @biosdumpcomputer | 26 May 2022 | Open file on RM Schematics |
| @skclappybios | 10 Apr 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 →