Programme-controlled logical systems in electronic telephone exchanges

Stored programmes are currently used for controlling logic operation in computer, industrial control and data-processing systems. The use of this technique in the common control of electronic telephone exchanges has been described by A. E. Joel, by N. N. Seckler and J. J. Yostpille, and others. In order to derive maximum profit from this concept, which appears to be new in the telephone switching art, its implications must be clearly understood and its essential features must be defined in the most general terms. As an approach to this end, the first part of the paper describes the necessary elements of a programme-controlled logical system for use in common control of an electronic telephone switching exchange. Some principles of logical operation are given, which may be considered for application. In the second part a specific example is described in more detail.