Abstract: The present invention is directed to a coded seal which allows a device to determine whether unauthorized access to a terminal or other electronic or security device has been made. The code includes a series of continuous and discontinuous members which are used to form a code. Breaking of the seal causes the members to be discontinuous and makes it difficult to determine what the code was. In this way, it is difficult to replace the seal, as this would only be successful if the replacement seal had the same code.

Abstract: Multi-party conferencing apparatus for use in a pulse code modulated, time division multiplexed telephone communication system including a data bus on which operating times are divided into equal frames of time and each channel of a plurality of channels has a transmit time slot and a receive time slot in each time frame. Voice signals on conferencing channels are sampled in each time frame and compared in the conferencing apparatus with the highest amplitude sample being rturned to all conferencing channels except the channel on which it originated and a second highest amplitude sample being returned to the channel originating the highest sample.