The 83B1 teletypewriter selective-calling system

During the last decade and a half in particular, the use of teletypewriters on leased lines has grown very rapidly. The Bell System now has more than 50,-00 such teletypewriter stations in service. In order to obtain the most communication for the least over-all cost, it is common practice, where the traffic load on the line will permit, to operate several stations on the same line. This results in a significant reduction in line cost compared with a line facility for each pair of stations. However, such multistation lines involve operating complications which somewhat offset the lower cost.