The card translator for nationwide dialing

Nationwide operator and customer dialing requires the existence of a number of switching centers equipped with automatic systems having a much higher order of mechanical “Intelligence” than previous systems. One of the most important components of this new switching system is the Card Translator. Its function is to take the telephone address of a call and determine how to advance this call toward that address. This translator has to meet unique requirements in that it must accommodate a very large number of addresses; must provide a great amount of information for routing the calls; and must enable quick and convenient changes to be made in its stored information. It must also meet, of course, the normal basic requirements of reliability, economy, long life, etc. The fundamental principle of this translator is that of a card file, containing individual coded cards for each destination, with routing information recorded on each card. Whenever the routing information for a specific code is needed, the, system, selects the appropriate card, and reads the information by means of electronic circuits employing phototransistors and transistor amplifiers.