No. 1 ESS ADF: Message Processing Program Organization

This article describes the system organization and objectives of the No. 1 Electronic Switching System Arranged with Data Features. The new hardware and software designs required to adapt a No. 1 ESS to a store and forward system are outlined with emphasis on the techniques used to get large system capacity, continuous reliable operation, and flexible service features. System operation, traffic capacity, and use of the new system are also discussed in this introduction to seven detailed articles.

No. 1 ESS ADF: System Organization and Objectives

Ewin¹,

Giloth²

1970

No. 1 ESS ADF: Magnetic Tape Subsystem

Potter¹,

Strebendt²,

Williams³

1970

>The No. 1 ESS ADF magnetic tape subsystem provides a high‐volume, low‐cost storage medium in which user messages are filed, and from which current message copies can be automatically retrieved upon user request. Message handling and statistical information concerning all message switching transactions are also filed on tape, providing a journal record for the switching center. Emphasis on maintenance and defensive programming techniques enables the tape subsystem to provide continuous and excellent service. This article describes the tape equipment and program package.

No. 1 ESS ADF: Teletypewriter Stations and Transmission Facilities

Carney¹,

Fitch²,

Parker³

1970

A solid-state electronic station controller, small enough to be hxmsed within Model SS, SB and 37 teletypewriters, administers station on-line procedures. To realize automatic message reception and transmission at the station, the controller samples all traffic exchanged between the line and the station teletypewriter, detects measage-and device-control characters and generates and detects station-identity codes. In addition, the controller monitors the status of the station teletypewriter and provides appropriate alarms which are displayed on an attendant unit.Stations are linked to the No. 1 ESS ADF office via the Bell System's private line telegraph network. New ac and dc data sets have been developed to accommodate speeds up to SOO bauds with lower distortion and crosstalk generation than previously attainable with former transmission apparatus.