The 4000 series was introduced as the CD4000 COS/MOS series in 1968 by RCA as a lower power and more versatile alternative to the 7400 series of transistor-transistor logic (TTL) chips.
4000-serien blev introduceret af RCA som CD4000 COS/MOS serien i 1968, som en lavenergi og mere bred anvendelig alternativ til 7400-serien af transistor-transistor logic (TTL) logik mikrochips.