Logic datasheet stored as SDLS164, a PDF of 667 KB. The file name holds just the literature number, a format used by Texas Instruments for its logic device documentation, so the exact chip is identified only inside. Such a sheet supplies the pin map, timing data, recommended operating conditions and package drawings needed for troubleshooting or sourcing a replacement. Any PDF reader opens it. Check that the logic family and package on the physical part match the variant described before swapping.
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 @datasheet_technar_org. 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.