Precession patterns in a delay line memory

Abstract

The SCM COGITO-240 is an electronic desk calculator which makes use of one sonic (magneto-restrictive) delay line as its primary memory element. Some 480 bits of information are held in the delay line circulation pattern. These are represented in a Pulse-No Pulse code; the insertion of a pulse into, or its emergence from, the delay line at a particular moment indicates the value one for the corresponding information bit. The absence of that pulse represents the value zero. For a memory unit of this type it is convenient to recirculate information at a rate which is of the order of 106 bits per second. Thus a convenient value for the delay time of the line, and for the time of one complete recirculation of the stored information, is about one-half milli-second.