Texas Instruments logic datasheet in PDF, 413 KB, identified only by its SDLS literature number rather than a part name. TI uses the SDLS prefix for its bipolar TTL documentation, so this most likely covers one or more 74-series devices, but the exact part must be read from the cover page. Typical use in repair is checking pin functions, supply pins and output types before probing signals on a board. Always verify the device marking and package type against the document before ordering a replacement.
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.