DM8000 series TTL
National Semiconductor DM8000 series of Logic ICs are fully compatible with standard 74 series TTL logic. These were produced at the very end of the 60's and into the early 70's. The adoption of the standard date code marking appears after 6925 (25th week of 1969), before this, just the week code (two digits) was printed. Hence a device with a NS 04 marking should correlate to 6904.