Translations in the No. 1 Electronic Switching System

The information recorded in the storage or memory units of a No. 1 ESS office consists of four parts: (1) the transient information about telephone calls in progress and the present state of all lines and trunks in the office, (2) a program for controlling all system operations that is basically identical in all offices, (3) a parameter table in the program store (semipermanent storage unit) containing certain information which varies from office to office and which changes only when major additions are made to an office, and (4) translation information, which includes the bulk of the information that varies from office to office, some of which changes from day to day. This article is concerned with the translation information and the portion of the program that is used to fetch and administer this information. The following are the basic categories of translation information, described for the moment in simple form. (1) Originating line translation: this translation indicates any special treatment of an originating subscriber, and specifies the directory number to be charged for his calls. 2533