Abstract: The invention relates to a system for giving an audio-visual presentation consisting of a basic part and at least a complementary part, such as a video film. The system comprises different storage media for storing the basic part and the complementary pan and merging means for merging the basic part with the complementary part into the audio-visual presentation. The complementary part is intended for enhancing the audio-visual presentation quality that can be achieved with the basic part. A provider may provide a basic part free of charge on a CD-i disc, after which the user is to pay for the complementary pan which may be transmitted to him via a telephone line from a databank.

Abstract: A hierarchical memory system for use with a high speed data processor characterized by having separate dedicated cache memories for storing data and instructions and further characterized by each cache having a unique cache directory containing a plurality of control bits for assisting line replacement within the individual cache memories and for eliminating many accesses to main memory and to insure that unnecessary or incorrect data is never stored back into said main memory.The present cache architecture and control features render broadcasting between the data cache and instruction cache unnecessary. Modification of the instruction cache is not permitted. Accordingly, control bits indicating a modification in the cache directory for the instruction cache are not necessary and similarly it is never necessary to store instruction cache lines back into main memory since their modification is not permitted.

Abstract: A Minimum Delay Module Assembly, having unrestricted accessibility for servicing, that provides substantially constant electrical and thermal environments for all portions of the assembly regardless of configuration. The assembly comprises a plurality of vertical page modules in which each page module is vertically hinged to the adjacent page module. Electrical interconnections are provided between the page modules by means of cable assemblies which enter each page module in the edge thereof adjacent said hinges. Individual self contained cooling means are provided for each page module so that the flow of air is up through the bottom of each page module and out through the top thereof. Resilient conduit means may be utilized to supply a pressurized coolant to each page module regardless of the configuration of the module assembly.

Abstract: In a delta modulator a sequence of code symbols are generated which are indicative of increments of signal level, with each code symbol being determined in accordance with the difference in signal level between an input signal and a prediction signal which is a representation of the input signal. A sequence of the generated code symbols are stored, including the most recent code symbol and a preceding number of code symbols, with the pattern of code symbols at any instant defining a state of signal activity. There is a table of delta increments, a table of threshold values, and a digital gain logic network, all of which provide signal outputs which are controlled by the state of signal activity represented by the stored code signal pattern. The signal output from the delta table and the threshold table are modified an amount determined by the value of the signal output from the digital gain logic network.