The logical function is performed by the input resistor network and the invert function is accomplished by the common emitter transistor configuration... Cite book URL http://ibm-1401.info/Form223-6889-TransistorComponentCircuits.pdf Title Transistor Component Circuits Last name IBM First name IBM Publisher IBM Year of publication 1960 Series identifier Customer Engineering Manual of Instruction id Form 223-6889 Quote The logical function is performed by the input resistor network and the invert function is accomplished by the common emitter transistor configuration... URL access date 2010-01-04 Authors list IBM ↑ Apollo Guidance Computer schematics, Dwg.