Abstract: An audio program and message distribution system in which a host system organizes and transmits program segments to client subscriber locations. The host organizes the program segments by subject matter and creates scheduled programming in accordance with preferences associated with each subscriber. Program segments are associated with descriptive subject matter segments, and the subject matter segments may be used to generate both text and audio cataloging presentations to enable the user to more easily identify and select desirable programming. A playback unit at the subscriber location reproduces the program segments received from the host and includes mechanisms for interactively navigating among the program segments. A usage log is compiled to record the subscriber's use of the provided program materials, to return data to the host for billing, to adaptively modify the subscriber's preferences based on actual usage, and to send subscriber-generated comments and requests to the host for processing.

Abstract: A broadcast recording and playback device employing a "circular buffer" which constantly records one or more incoming audio or video program signals and a microprocessor for accessing the memory to read a playback signal from the circular buffer to display programming material delayed from its receipt by a selectable delay interval. The circular buffer is implemented by a digital memory. Subsystem comprising the combination of a semiconductor RAM memory and a disk memory operated under the control of a microprocessor such that incoming signals are constantly recorded as received while, at the same time, delayed signals are being read from the memory subsystem at a different memory location selected by a microprocessor to provide a user-selected time delay.