Logic Circuits for a Transistor Digital Computer

The reliability and performance which can be achieved in high-speed switching circuits using presently available high-frequency junction transistors suggests the use of transistor circuits in preference to more conventional circuits for many applications. The area of airborne digital computers is one in which the physical characteristics of the transistor as well as of associated low dissipation components can be most favorably exploited. We have presented here a group of circuits which fulfill the requirements of speed, low dissipation, size, and weight for most such applications. The circuits shown will operate over the range ¿30°C to +60°C, and actually have been operated over the range ¿50°C to +90°C. Low dissipation of the circuits places minimum requirements on power supplies, and temperature control may be achieved with only a small amount of cooling. An estimate can be obtained from an example. For a large-scale computer, say 2000 transistors, 800 of which are in bistable circuits, total dissipation will be less than 140 watts.