Logic Families - RTL

RTL

The Atanasoff–Berry Computer used resistor-coupled vacuum tube logic circuits similar to RTL. Several early transistorized computers (e.g., IBM 1620, 1959) used RTL, where it was implemented using discrete components.

A family of simple resistor–transistor logic integrated circuits was developed at Fairchild Semiconductor for the Apollo Guidance Computer in 1962. Texas Instruments soon introduced its own family of RTL. A variant with integrated capacitors, RCTL, had increased speed, but lower immunity to noise than RTL. This was made by Texas Instruments as their "51XX" series.