Lenovo ThinkPad firmware tied to the NM-B901 board, with the name listing the FT490, FT492, FT590 and FT591 platform codes. NM-xxxx numbering is the LCFC pattern used for Lenovo-built boards, often shared across several ThinkPad models. The 10.2 MB archive likely holds a BIOS and possibly EC images for SPI programming. Check the board number on the PCB, read and save the original chip before writing, and match the image size to the flash capacity, since ThinkPads store unique system data in the chip.
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 →