Abstract: A pulse code modulation (PCM) unit is connected to a bus in a computer system. Also, connected to the bus is a processor and memory. The PCM unit is connected to transmit and receive telephone lines. The PCM unit reads uncompressed PCM data from the memory over the bus and compresses the PCM data for transmission over the telephone line in a cycle steal operation, wherein the bus is not being used by the processor. The PCM receives compressed PCM data from the receive telephone line, decompresses it, and writes the decompressed PCM data to the memory in a cycle steal operation. In addition, selectivity of either .mu.-Law or A-Law conversion, selectivity of even bit inversion for A-Law conversion, and selectivity between the compressed/decompressed PCM data or raw data is provided on a per channel basis. Selectable linear gain is also provided.

Abstract: In an communication system including a computer system comprising a digital signal processing adapter for performing a-set of tasks, and a E-1 port for providing and receiving time division multiplexed (TDM) signals in accordance with a first inter-system communication protocol, such as the E-1 or T-1 protocols, a communication subsystem, for coupling to the IP system. The communication subsystem includes an E-1 link for coupling to the first I/O port, and for providing and receiving TDM signals in accordance with the E-1 or T-1 protocols. The subsystem further includes a digital signal processor adapter, coupled to the second I/O port, for enhancing processing capability of the digital signal processing resource; and a third I/O port, coupled to the digital signal processor circuit, for providing and receiving signals in accordance with the first or a second inter-system communication protocol.

Abstract: This disclosure is for an Audio-Visual training device having both a projectable film tape and an audio tape with control indicia on the audio tape in addition to recorded audio messages. The tape indicia are used to control a small processor which governs both tape and film movement. A keyboard on the device is used to enter replies to queries to a user from the tape and film and the processor will determine both tape and film movement in response to the answer to a query. The system is capable of multiway branching to present to the viewer the proper information pertaining to his answer. Several counters are available to count trials, correct or incorrect responses, etc., and to control tape and film movement in accordance with the counter readings. A proctor light may be turned on to call for personal assistance and to lock up the machine when a student is in trouble and the program does not have the proper branch to clear up the difficulty.