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A Coincident-Current Magnetic Memory Cell for the Storage of Digital Information, 1952 April

 File — Multiple Containers
Identifier: 16

Scope and Contents

MIT DIC 6889. Project Whirlwind Controlled Distribution Memo 6D-95. A small, ring-shaped, ferromagnetic core with properly "rectangular" B-H characteristics may be operated so that its flux polarity reverses only when the correct combination of two or three magnetizing windings are coincidentally excited. Such cores may then be used as memory devices and assembled into a two- or three-dimensional memory system with storage-cell selection at the intersection of two or three space co-ordinates. Only a core which retains a large percentage of remanent flux of the proper polarity, in spite of repeated "nonselecting" disturbances, can be used as a coincident-current magnetic memory unit. Repetitive pulse-pattern testing designed to obtain quantitative data on the operation of such units, in the form of defined "information-retention ratios" and "signal ratios," indicates that only a few core materials are satisfactory. Reprinted from the Proceedings of the I.R.E. Vol. 40, No. 4, April, 1952.


  • 1952 April



From the Collection: 3.9 Gigabytes (4035 MB in 1835 digital files in 31 folders)

From the Collection: 56.3 Cubic Feet (189 boxes including 142 microfilm reels)

Language of Materials

From the Series: English

Repository Details

Part of the Massachusetts Institute of Technology. Libraries. Department of Distinctive Collections Repository

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