SNJ54S240J vintage, military-grade digital logic chips.

Component Identification

​These are vintage, military-grade digital logic chips. The markings on the top of the package provide a wealth of information:

​SNJ54S240J: This is the primary part number, which breaks down as follows:

​SNJ: A prefix used by Texas Instruments (TI) for military-grade parts.

​54: Indicates the military temperature range of -55°C to +125°C.

​S: Designates the "Schottky" family of Transistor-Transistor Logic (TTL), which is a high-speed version of standard TTL.

​240: The specific function code for an Octal Buffer/Line Driver with 3-State Outputs.

​J: The package code for a hermetic ceramic dual in-line package (CDIP), which is a rugged, sealed package suitable for military and aerospace applications.

​TAIWAN: This indicates the country where the chip was manufactured.

​A8734Y: This is a date code. The "87" most likely represents the year of manufacture (1987), and "34" indicates the 34th week of that year.