PDF listed as a schematic for the 28F020, with Intel named as the manufacturer in the file name. The 28F020 is a 2 Mbit parallel flash memory part. At 879 KB this edition is considerably larger than the other 28F020 files, suggesting a fuller datasheet with more diagrams or timing data. Use it for pinout, command set, programming voltage and erase algorithm when working on older boards with a parallel programmer. Confirm the chip on the PCB carries matching Intel markings before relying on vendor-specific timing.
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.