磁圈記憶之選擇系統

Abstract

Magnetic cores with rectangular hysteresis loop have been and still are the most common elements used in the memory of computers. The purposs of this paper is to give a survey of all the techniques which has been developed in selecting and driving the practical magnetic-core memories, and which play the most important role in determining the speed of the computers. In order to understand the design techniques and the function of the memory and various selection systems, and introductory description of the characteristics of the magnetic core is given in Part I. Conventional medium-speed and low-speed compters use the coincident current memory. Various selection matrix switches and other technique such as a current-steering decoder may be used to drive this kind of memory. In Part II, such selection systems are given. The logic functioning of respective selection method are described in detail and often the advantages and the disadvantages of each method are given for comparison. Recent high-speed computers employ the word-organized core memory and partial switching technique in addition to the selection matrix switch techniques described in Part II to reduce the memory cycle time and at the same time reduce the power otherwise required. Part III gives a general description of this new memory construction, and the principle involved. Two typical types of word-organized memories of practical use are also given.