Robert C. Minnick

Linear-Input Logic

Techniques are developed for the logical design of magnetic core circuits to produce arbitrary single-output combinational switching functions. The approach is based on the relationship of a single magnetic core circuit to a linearly separable switching function. A synthesis procedure is developed which uses a pair of logical primitives, AND with NOT and OR with NOT, which are similar to the STROKE primitive and its inverse. Procedures are developed for the synthesis of symmetric functions which require no more than the integral part of (n+3)/2 cores, approximately half the number used in previously published procedures. The synthesis of arbitrary switching circuits is treated as a linear programming problem, and a table of all four-variable circuits is presented in which no circuit requires more than three cores.

Cutpoint Cellular Logic

A cutpoint cellular array is a two-dimensional rectangular arrangement of square cells, each of which has binary inputs on the top and left edges and outputs on the bottom and right edges. Each cell is interconnected with neighboring cells, and it is specialized by a set of binary constants that are termed cutpoints. This paper is concerned with the choice of the logical properties for each cutpoint cell, so that an array of these cells is capable of efficient and general combinational and sequential logic. Logical design algorithms are given, as well as a number of actual designs. It is believed that cutpoint cellular arrays have promise for application in the manufacture of a large number of integrated circuit components on one substrate.

Cobweb cellular arrays

The cobweb cellular arrays are embellishments of the cutpoint cellular array that are made by complicating the cell-interconnection structure. This new class of arrays will allow for more economical and efficient logical designs than are possible in cutpoint arrays. As a background to the new arrays, the properties of the cutpoint array will be reviewed.

Magnetic Core Access Switches

A number of the more commonly known magnetic core access switches are combined in a single analytical model. In addition to yielding as special cases the known access switches on which it is based, this model produces many apparently new switches. Relationships among the various parameters in this model are developed in such a way that the designer may choose the number of drivers, the load-sharing factor, the number of turns of wire per switch core and the magnitude of the maximum disturbing magnetomotive force within certain limits. Several methods are developed for economizing on the number of drivers used in switches, and certain special access switches are treated. The current knowledge is reviewed on a fairly recent and important class of access switches, known as load-sharing zero-noise switches. These switches are compared with one another, and a fundamental theorem is proved that such switches can have no more outputs than inputs. Several new classes of load-sharing zero-noise switches are developed and analyzed; in particular, switches are developed which allow more flexibility in the choice of the load-sharing factor than formerly was the case.