Abstract :
Transistors are at present the most suitable power-gain devices for use in parallel digital computers on account of their small size, low power consumption and high presumptive reliability. However, the design of the building-block circuits, which are logically interconnected in large numbers to form the computer, must guarantee adequate performance in spite of contemporary transistor disadvantages¿their characteristic spreads, restricted frequency response and limited power dissipation. The paper describes how transistors can be used with diode logic to satisfy some fundamental requirements peculiar to binary amplifiers and 2-state elements. Feedback saturation control is generally adopted; building-block circuits incorporating this feature are described. Satisfactory operation at 1 megapulse/sec is obtained using 5Mc/s alloy-junction transistors. Some specific arithmetic and counting applications are discussed. When binary amplifiers fail to give adequate frequency response, or adequate power-handling capacity, because of transistor limitations, master-pulse techniques may provide a solution. These techniques are discussed and their application to the ferrite-core-store drive problem is described.