Datasheet archive for the SMSC LPC47N350, as the ds suffix in the name indicates, packed as a 1.87 MB RAR. The LPC47N350 is an SMSC keyboard and embedded controller part found on older notebook boards, and its datasheet gives the pinout, power pins, LPC bus interface and register details. Technicians use it to check supply and clock pins, trace keyboard matrix and power button lines, and confirm which pins reach the firmware flash. Extract the archive with any RAR-capable tool and open the PDF in a standard reader.
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 @generalschematics. 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.