Abstract: A circuit board interconnection system comprising an edge mounted electrical connector and at least one cable connector. The edge mounted connector comprises a body having a plurality of electrical contacts retained thereon with each contact including a circuit board engaging portion and a terminal engaging portion. At least one receptacle is formed by a flange extending from the body about the terminal engaging portions. The cable connector comprises a body including a pluraity of terminals thereon connected to a source of electrical potential and arranged to be inserted into the edge connector receptacle electrically interconnecting respective terminals to edge connector terminal engaging portions.

Abstract: Common digital line circuits are used in a digital telephone office to provide supervisory and digital conversion functions for any subscriber station connected to a digital telephone office. Subscriber stations are connected to specialized analog line circuitry via an analog access network when required.

Abstract: A current regulated pulse dialer circuit for use in a loop powered pulse dialing telephone. A current source is connected to an electronic pulse dialer to provide high impedance across a telephone line during transmission and interpulse pause conditions.

Abstract: Pulse Code Modulation (PCM) line circuits include analog and PCM processing circuitry. These circuits are separated into an analog line circuit portion and a PCM processing circuit portion. An analog network is connected to the analog line circuits and provides concentration to a minimal number of PCM processing circuits.

Abstract: A shared maintenance terminal system permitting the joint use of a teletypewriter located at a telephone switching center by the switching center and by a remotely located data processing center. This maintenance terminal system provides interlock control for input and output messages from a craftsman located at the telephone switching center or from personnel located at the remote data processing site.

Abstract: A telephone ringing signal generator which sequentially produces a plurality of ringing signals each of a different frequency. Each of a plurality of tone ringers connected to the generator will ring only in response to it's particular frequency. A programmable oscillator generates the required frequencies under control of a time slot generator which defines the time slot during which each frequency is to be generated.

Abstract: A noise eliminator circuit for use in a decoding circuit. A flip-flop is used to delay a first pulse train by the pulse width of a second pulse train so that pulse level transitions of the first pulse train occur non-coincident with the pulse level transitions of a synchronously generated third pulse train.