Texas Instruments logic datasheet, 529 KB PDF, labelled only with an SDLS literature number, the series TI uses for its standard bipolar TTL documents. The name does not reveal the part, so the device has to be read from the cover page; the size suggests a scanned or multi-device document. Such datasheets supply pinouts, truth tables, supply ranges and propagation delays for in-circuit testing and finding substitutes. Make sure the part number and package printed on the chip correspond to what the document covers.
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.