Combined BIOS and EC firmware package for a Sony VAIO built on the MBX-223 motherboard, as the name indicates both images are included. The 1.62 MB RAR archive should contain separate files for the main SPI flash and the embedded controller. MBX-xxx is Sony's own board numbering, printed on the PCB, so confirm it before flashing. A matching EC image matters when the laptop shows no power or charging faults. Back up both original chips with a programmer before writing any data to them.
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 →