Operates as inverting power amplifier for either pulses or levels. Input levels are -6.2 v at 3.1 ma for logical 1 and -0.15 v for logical 0. Pulse polarity may be positive or negative 6 v. Third transistor is used for handling up to 40 flip-flop or gate loads. Two transistors will handle up to 12 such loads.-NBC, "Hand-book Preferred Circuits Navy Aeronautical Electronic Equipment," Vol. II, Semiconductor Device Circuits, PSC 12 (originally PC 215), p 12-2.