What year was the CD4041 / HEF4041 introduced?

Question

Most of the 4000 series CMOS logic was available and fairly established in the mid-70s. I’ve had some trouble figuring out when the CD4041 quad positive/complement driver was introduced - and by which companies. It’s a rather useful part, as it’s about 2x faster than the unbuffered inverters, has good drive capability, and the complementary output transitions are well aligned across the whole range of supply voltages. I’m relying heavily on this part for retro-style discrete logic designs.

Answer 1

I would say it's been there right from the beginning, as part of the original RCA COS/MOS line up in 1968. The oldest reference short googling brought up is RCA's 1972 COS/MOS Integrated Circuits Manual.

(Bitsavers also got the 1975 manual)