BIOS dump for the Lenovo ThinkPad SL400, marked OK in the name, which suggests it was tested and confirmed working. The 700 KB RAR should contain an image for writing to the BIOS flash chip with an SPI programmer. Since SL400 boards came in different configurations, compare the board and memory type before using it. Read the existing chip and keep the copy, and check that the extracted image size equals the chip capacity so it can be written and verified without errors.
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 →