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Read-Only Thin Film Memory

IP.com Disclosure Number: IPCOM000097175D
Original Publication Date: 1962-Jun-01
Included in the Prior Art Database: 2005-Mar-07
Document File: 2 page(s) / 60K

Publishing Venue

IBM

Related People

Taren, WJ: AUTHOR

Abstract

Memory systems employ matrix arrangements of uniaxial, anisotropic thin magnetic film elements. The circuit shown employs a selectively punched metallic shield adjacent a thin film matrix to control the content of stored data. The presence of a metal shield adjacent a thin magnetic film spot greatly reduces the amount of flux coupled from the spot into an associated sense winding The memory device shown takes advantage of this phenomenon to provide a read-only or semi-permanent information storage device.

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Read-Only Thin Film Memory

Memory systems employ matrix arrangements of uniaxial, anisotropic thin magnetic film elements. The circuit shown employs a selectively punched metallic shield adjacent a thin film matrix to control the content of stored data. The presence of a metal shield adjacent a thin magnetic film spot greatly reduces the amount of flux coupled from the spot into an associated sense winding The memory device shown takes advantage of this phenomenon to provide a read- only or semi-permanent information storage device.

An array of uniaxial anisotropic, thin magnetic film spots 10 is supported in matrix formation on a metallic substrate 12. A group of drive lines 14 is provided above the spots. Each drive line overlies a separate word group of spots. Sense lines 16 are provided between the word windings and the spots. Each line 16 overlies a corresponding spot from each word group. Suitable insulation 18 is provided between the spots 10, lines 16 and lines 14.

Spots 10 are oriented so that their easy axes of magnetism are transverse to the fields produced by the word lines. Energization of a word line 14, therefore, produces an orthogonal field to switch the magnetic flux in an associated spot from its easy axes of magnetism into the hard direction. The flux change produced by this change of magnetism is coupled into the sense line 16 associated with the spot to induce a voltage in it.

The information content of the array is controlled by a metal pla...