Abstract: The preferred embodiment of the present invention varies the speed of processor execution, including associating a clock rate with each thread in a plurality of threads and executing each thread in the plurality of threads on the processor at the clock rate associated with the thread.

Abstract: In a conditional access system, a system and method for descrambling a scrambled instance having a predetermined encryption cycle rate is claimed. The invention takes advantage of the inherent encryption period associated with a scrambled instance to control subscriber access to scrambled information.

Abstract: A reprogrammable subscriber terminal of a subscription television service which can have the control program code of its control processor modified by downloading new program code from the headend. The control processor stores a boot program in an internal read only memory. Upon start up and resets, the boot program determines whether the control program should be changed from a command sent from the headend. The command, termed a parameters transactions, includes the number of expected download program code transactions required to complete the control code modification, the memory space areas where the code is to be loaded, and the channel over which the download program code transactions are to be transmitted. The channel is tuned and when the boot program receives all the download program code transactions accurately and stores them, the boot program will cause the control program to be restarted at a selected address of the new or modified control program code which has been downloaded.

Abstract: A reprogrammable subscriber terminal of a subscription television service which can have the control program code of its control processor modified by downloading new program code from the headend. The control processor stores a boot program in an internal read only memory. Upon start up and resets, the boot program determines whether the control program should be changed from a command sent from the headend. The command, termed a parameters transactions, includes the number of expected download program code transactions required to complete the control code modification, the memory space areas where the code is to be loaded, and the channel over which the download program code transactions are to be transmitted. The channel is tuned and when the boot program receives all the download program code transactions accurately and stores them, the boot program will cause the control program to be restarted at a selected address of the new or modified control program code which has been downloaded.

Abstract: A display system for providing programmable on-screen displays for a subscriber terminal, includes a control processor and a display processor which generates such displays from stored display information and display attributes. The control processor executes display routines to configure the display processor and to load the display data into a display memory. The display routines, display attributes and display data are programmable and can be varied for optimal use of the display processor. In one implementation, such information can be modified by changing the programming in non-volatile memory of the subscriber terminal, either by switching ROM or Flash EPROM ICs or by a plug in module. Another implementation includes downloading the information with other executable code and data in the read/write portions of the non-volatile memory.

Abstract: An auxiliary device control for a subscriber terminal includes a four wire ribbon cable defining a bidirectional communication and data interface from the terminal to one or more auxiliary devices. A communication and data protocol for the bidirectional transfer of instructions, status, and data over the interface includes an address field, command or reply field, data length field, and checksum field transmitted at 9600 baud. In a preferred implementation, the auxiliary device to be controlled is an IR peripheral controller which can tune a VCR, and switch it on and off. Several transactions in the communications and data protocol are used to effect the operation where a control VCR command and reply transaction cause the control of the tuning and recording of the VCR. A set-up VCR command and a brand reply transaction is used to provide information to configure the controller with brands and model of the VCRs.

Abstract: A display system for the on screen display of information for a subscriber terminal of a subscription television system includes a display processor which can display information in the form of a display screen stored in a display memory. The display processor can be preprogrammed by the control processor with a plurality of display attributes including different symbol sets, different color palettes, whether the screen is to be a text screen, graphic screen or a combination of a text and graphics system, and the size and location of each screen display on the display area. The display processor includes a digital processor and an analog processor. The digital processor controls accessing the display data from the memory and converting it into timed digital pixels. The analog processor includes a digital to analog pixel converter which produces analog pixels from the digital pixels in a timed relation to an input video signal.

Abstract: A headend of a subscription television system includes a video combiner that combines video signals from four separate programs into a composite video signal. The video signals are formatted to produce the composite video signal such that one of the programs appears in each quadrant of the displayed picture. Text data streams are then inserted into the vertical blanking interval of the composite video signal. The composite video signal is transmitted in a channel of a broadband television signal to a plurality of subscriber terminals. A plurality of virtual channels are defined by combinations of quadrants of the composite video signal and quadrants of text from the text data streams. When the subscriber selects a virtual channel, the composite video signal is tuned from the broadband signal, and the text data stream forming the text display of the virtual channel is extracted.

Abstract: Apparatus for providing a user friendly interface to a subscription television terminal comprises a key pad arranged into a plurality of key groupings and an on-screen display controller for generating a plurality of screens for display on an associated television receiver. Five such key groupings are segregated from one another and comprise function keys, initialization keys, channel keys, audio keys and digit keys. The digit keys may be most conveniently arranged in a two dimensional matrix corresponding to a key pad of a conventional tone dialing telephone. Each of the other key groupings may be arranged linearly and differentiated by the use of color or boxes. A method of initializing the cable television terminal comprises the steps of generating a display of a menu structure, actuating the movement of a cursor in one direction through choices presented by a menu by use of a cursor key, and actuating a selection of a menu choice via actuation of a select key.

Abstract: A reprogrammable subscriber terminal of a subscription television service which can have the control program code of its control processor modified by downloading new program code from the headend. The control processor stores a boot program in an internal read only memory. Upon start up and resets, the boot program determines whether the control program should be changed from a command sent from the headend. The command, termed a parameters transactions, includes the number of expected download program code transactions required to complete the control code modification, the memory space areas where the code is to be loaded, and the channel over which the download program code transactions are to be transmitted. The channel is tuned and when the boot program receives all the download program code transactions accurately and stores them, the boot program will cause the control program to be restarted at a selected address of the new or modified control program code which has been downloaded.

Abstract: A television system having sync suppression scrambling and descrambling which includes in band and out of band signaling methods. The in band signaling method modulates the IF sound carrier of a premium video channel with timing and data pulses while the out of band signaling method modulates the previously modulated IF sound on a separate carrier onto a separate out of band data carrier. The in band signaling method uses a descrambler which tunes a channel before demodulating the timing and data pulses from the sound carrier while the out of band signaling method tunes a selected data carrier to demodulate the timing and data pulses. In both methods, the timing pulses are used to restore the levels of the synchronization pulses in the sync suppressed video signal, and thus descramble the signal, while the data pulses are used for addressable messaging to the descrambler including authorization.

Abstract: A subscriber terminal apparatus for a television in an in-band subscription television system is provided. The subscriber terminal includes a receiver for receiving a television signal including video, audio, ana data information. A selector selects a channel of the television signal. A memory stores a plurality of barker screens providing messages regarding one or more channels of the television signal. An on-screen display control circuit controls the display of the barker screens on the television. A processor retrieving a barker screen from the memory supplies the retrieved screen to the on-screen display control circuit if the barker screen provides a message regarding a selected channel. Barker screen information may also be obtained from a dedicated data channel or a six megahertz video barker channel.

Abstract: A subscriber terminal includes a receiver for receiving a television signal including video, audio, and data information. A channel of the television signal may be selected for display on the television. A memory stores channel identification information such as channel identifiers. The channel identifiers include at least one display character. A processor establishes a relationship between channel identification information and channel numbers associated with channels of the television signal. An on-screen display control circuit controls the display of character information on the television and has the capability of overlaying the channel number and the channel identification information on the video portion of a selected channel displayed on the television for a predetermined period of time. Program identification information such as program titles may also be displayed.

Abstract: A subscriber terminal apparatus for a television in an in-band subscription television system is provided. The subscriber terminal is adapted to receive a television signal including video, audio, and data information. A tuner of the subscriber terminal tunes channels of the television signal and an on-screen display control circuit selectively provides a display of characters on the television. A tuner control tunes the tuner to a channel having in-band data when the display of characters is provided on the television.

Abstract: Volume control for use in a cable television set top converter or the like is calibrated for optimum television stereo channel separation. The volume control controls the volume to predetermined levels. One of the predetermined levels is a particular level calibrated for optimum stereo separation. An indicator on the converter indicates the optimum stereo separation volume level. When an internal VCR timer turns on the set top converter, the set top converter is forced to the optimum stereo separation volume level. The calibration is performed during manufacture and ensures that the indicated volume level for optimum stereo separation is indeed the optimum volume level.