A 108 KB PDF stored as a schematic and titled 28F020, the part code of a 2 Mbit parallel flash memory in the 28F family. Vendor, speed grade and package are not given in the name. The document is the place to check pin assignment, erase and program sequences, supply and programming voltages. Repair technicians use it when reading out or restoring firmware on older mainboards and equipment with a universal programmer. Always save the original contents first and confirm the chip suffix matches the sheet.
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.