No. 1 ESS ADF: System Testing and Early Field Operation Experience

A No. 1 Electronic Switching System Arranged with Data Features (No. 1 ESS ADF) was installed in New York City to operate and control the Long Lines Department's nationwide Administrative-Data Network (ADNet) -1 The new system was cut into service February 3, 1969, and connects some 720 Long Lines, Operating Company, and Western Electric Company locations to the No. 1 ESS ADF switching center through 400 circuits which are terminated by 1,250 four-row teletypewriters that use the American Standard Code for Information Interchange (ASCII). Connection is also made to computers at two Long Lines data processing centers so that computer-generated data can be distributed by the network, or field data can be assembled for computer center processing. Large traffic handling capacity was needed for the ADNet. Therefore, a near maximum-sized system has been installed. Two autonomous data scanner-distributors terminate 1,024 full duplex or half duplex data lines which operate at speeds up to 150 words per minute. Call stores capable of handling 159,744 24-bit words, duplicated, are provided. Duplicated program stores of 327,680 44-bit words are pro2975