AbstractsComputer Science

The GALAXY computer is a large, high speed, general purpose, digital computer intended to be used for solving scientific problems. It requires a random access memory system of 16,384 words of 59 bits each with a cycle time of one microsecond or less. A memory system capable of meeting these requirements has been designed for ferrite core storage elements and transistor active elements. It consists of four sections of 4,096 words each, with the initial installation consisting of two sections. Each section has its own associated current drivers and sense amplifiers while the memory register, decode circuits, and timing unit are used in common by the whole system. An experimental investigation of the memory system gave evidence that the requirements could be met by using presently available commercial components. A linear selection system was selected and investigated by using a 64 core word line and a 4,096 sense line to simulate a core stack. The experimental results showed that a minimum cycle time of 700 nanoseconds could be obtained. The results of an investigation of the system com ponents were used to select the type of cores and plane configuration. Ferroxcube type 6F2 cores were used with a word line configuration of two turns per core and a sense line configuration of one turn per core. Distri buted capacitance was added to the sense line to achieve a purely resistive characteristic impedance and thus sub stantially reduce the post-write disturb voltage. The investigation and design of the associated elec tronic circuits are also discussed.