A 727 KB PDF titled 29010a, filed among schematics but most likely a datasheet edition for a 1 Mbit 29-series parallel flash memory, the a suffix suggesting a revision or variant. The name does not state the manufacturer or package type. It is consulted for pinout, sector layout, ID codes and programming commands when dumping or rewriting a firmware chip. Its size equals the plain 29010 file, so they may be duplicates. Back up the original contents before any write and verify the chip marking.
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.