Firmware archive for the ASUS PRIME B660M-A D4 desktop motherboard, BIOS version 2403 according to the name. The D4 variant takes DDR4 memory and is a separate board from the DDR5 model, so confirm the exact model printed on the PCB. ASUS desktop images often come as a .CAP capsule with a header that must be removed before burning to the SPI chip with an external programmer. Otherwise the file can be applied through EZ Flash or BIOS FlashBack. Back up the existing chip 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 →