Part-number-style PDF, 176 KB, labelled 27lc040 and listed here as a schematic. The pattern matches the 27-series UV or OTP EPROM family, with LC typically denoting a low-voltage CMOS variant. Nothing in the name identifies a device or board, so use it as a reference for the chip itself. It covers pinout, package options, read timing and the programming voltage needed by a programmer. Check the vendor logo and suffix on the actual IC, since different makers' sheets for the same number can differ in detail.
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 @cyberlanelectonik. Enginerys does not host this file.
How to open a .pdf file
The standard format for schematics, block diagrams, power-sequence charts and service manuals.