Abstract: Digital loop carrier system having CPU to channel unit protocol. A method of communicating with the protocol is used in a telecommunication system having at least a central processing unit (CPU) connected to a plurality of digital interface units (DIU) via a communication module (CM). Each of the digital interface units is connected to a plurality of channel units (CU).

Abstract: A channel redundancy system for use with a central office connected to a remote location. A central office terminal at the central office has a plurality of channel units including at least one spare channel unit. A remote terminal at the remote location also has a plurality of channel units including at least one spare channel unit. The channel units in the remote terminal are correspondingly associated with the channel units in the central office termimal. From a repair service bureau located remote from both the central office and the remote location in a defective channel unit can be identified and replaced by the spare channel unit.

Abstract: An intelligent interface arrangement is provided for controlling operation of peripheral devices including a video device and a random access slide projector from a computer. The computer via the interface arrangement also controls the audio and video inputs to the system monitor for the selection of either audio channel from the video device, no audio, or mixed audio. The video control includes selection of video from the video device or computer. The computer addresses the interface arrangement with a predetermined unique address code. The address also includes the category of video device to be controlled. Each command sequence from the computer to the interface arrangement includes a start of command byte, one or more command bytes and an end of command byte. Each communication command sequence also includes a video-audio device command byte for selection of desired audio and video modes.

Abstract: Apparatus is provided for the control of a video tape or cassette recorder by a microcomputer. The apparatus is interfaced to the video recorder for the input and output of various control signals via the remote control connector of the video recorder. The apparatus also includes interconnections to a microcomputer, a monitor and the audio and video signals of the video recorder. The apparatus under the control of the microcomputer controls operation of the video recorder and selectively supplies either video recorder video or microcomputer video to the monitor and independently supplies one of the two audio channels of the video recorder or no audio to the monitor. The apparatus under keyboard inputs from the microcomputer controls transport functions of the video recorder including rewind, fast forward, various play speeds, stop and pause.