Signetics Standard Logic
Fairchild's introduction of the integrated circuit and its 900 series RTL logic in 1961 revolutionised electronics. Eventually 25 standard logic circuits comprised the 900 series. The major downside of RTL (Resistor Transistor Logic) was the very high power dissipation through its on-chip resistors. In 1962 Signetics a spin out from Fairchild, introduced the SE-1000 series, the first major DTL (Diode Transistor Logic) family of ICs. In 1963, Sylvania introduced the first family of the further improved and faster TTL (Transistor - Transistor Logic), called SUHL (Sylvania Universal High Level Logic). Very quickly, Texas Instruments and others introduced their own families of standard logic functions. Initially TI gave the logic family the prefix 54, then the 74 series with a narrower operating temperature range. Fairchild and Signetics like other semiconductor companies, eventually followed the lead of TI and the ordering system for bipolar TTL. The Signetics 74LS161A from 1981, is...