Manufacturer datasheet, in PDF form, for the 128 Kbit serial EEPROM sold as 24AA128, 24LC128 and 24FC128. All three use the two-wire I2C bus and differ mainly in operating voltage and maximum clock rate. Use it to identify the pins, the write-protect input and the hardware address lines, and to set the right chip type in programmer software. Make sure the part marking matches one of these numbers and dump the original memory to a file first, since a failed write leaves the board without its stored settings.
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.