Magnetic-core memory elements characteristically require bipolar applied fields. The vanishing inner diameter of toroids and the loss of the third dimension entirely in deposited thin films demands minimization of the number of wires. A configuration which has been investigated and applied in a word organized memory at the University of California at Los Angeles is illustrated in Fig. 2. It consists of a pair of mutually inverted and parallel connected transistors. The transistors are not in general symmetrical. This paper discusses some of the system considerations which determine the important design parameters. Methods for location of regions of satisfactory operation in the many-variable space of the inverted transistor pair are described. Although a particular design problem is discussed, attention is focused on the question, ``What classical and new procedures can we use to reduce the number of dimensions in such design problems?'' The power of the computer as a design tool is crucially dependent upon such processes.