GB1037992A - Improvements in digital data storage devices - Google Patents

Abstract

1,037,992. Read-only stores. INTERNATIONAL BUSINESS MACHINES CORPORATION. June 26, 1963 [March 28, 1962], No. 11825/62. Heading G4A. A read-only store comprises rows and columns of sense and drive lines respectively and overlaying them a conductive sheet which to store a binary one is punched at intersections of the lines in a pattern which links the lines inductively and to store a zero a hole covering the intersection is punched. It is preferred that the conductive sheet is initially punched to store ones at all locations and that the store is of such a size that a hand card punch can be used to punch zeroes. In Fig. 3 a rectangular storage location is defined by the intersections of the drive lines 1 (a central conductor and two earthed return conductors) and guard conductors 3. The sense line 2 crosses the location to define six sub-rectangles. To store a binary one three of these are punched out as shown so that change of current in the drive lines induces a circulating current in the remaining subrectangles which in turn induce a current pulse in the sense lines. To store a binary zero all six sub-rectangles are punched out. Several other patterns for varying configurations of drive and sense lines are described in the Specification.