the invention is explained by way of reference to fig1 , which shows the main features of a system having input switching provisions . broadcast - frequency signals 2 from a standard antenna are received at the broadcast tuner 4 . these signals are demodulated into baseband audio and video signals , which then are provided to the audio / video switching matrix 22 . cable system signals 6 are provided to the cable tuner 8 , which as an option may include a descrambler module 10 ; this may be implemented either as an internal circuit board , an internal plug - in module , or an external plug - in unit , and this unit would be compatible with the scrambling system used on the particular cable system . depending upon the circumstances , one or more of the various tuners may interface to a decoder to receive other specialized information such as teletext or closed - captioning , though not referenced in the figures . optional satellite - receiver signals 12 are provided to the satellite tuner 14 , which , like the cable tuner , also may include an optional descrambler unit 16 , implemented through a similar range of methods as described above for the cable tuner . in some installations , the satellite receiver service would include its own tuner and / or descrambler means , in which case the signals would be input to the cable converter through one of several direct - connection inputs ( not shown ); these inputs would also allow for the integration of other sources , such as vcr playback signals . all of these input sources are demodulated and provided to the audio / video switching matrix as baseband audio and video signals , enabling signal routing within the audio / video switching matrix to be implemented as a baseband video “ bus .” the selected signal from the switching matrix is provided at the output 24 ; these signals are also optionally provided to an rf modulator 26 , for output as modulated signals 28 . in the preferred embodiment , the system provides for the association of one channel with one or more other channels carrying supplemental information . for example , one channel might carry the “ left - eye ” view of a stereoscopic signal , while a second channel carried the “ right - eye ” view . such additional channels may alternatively provide the following types of supplemental information , though the entire range of available information is by no means limited to this list : picture enhancement information ( as suggested by several of the proposed hdtv systems ) to provide wide - screen or other effects ; video - game related information , including information related to additional players ; digital data , such as statistical information about players in a sporting event or pricing / account information associated with a shopping channel ; additional audio information , including information which provides higher fidelity , stereophonic / surround - sound effects , foreign language audio , “ sing - along ” lyrics to accompany a popular music concert , etc . teletext or closed - captioning information . in this embodiment of the invention , a primary channel will typically carry “ primary ” program information along with additional information used by the system for directing a second tuner to a secondary channel ; other channels could be similarly associated . the information relating a primary channel to one or more secondary channels carrying supplemental information may be derived in various ways . for example , the primary channel may carry a pointer to the additional channel ( s ), for example , in a subcarrier , or as part of synchronization as during vertical retrace . such a pointer may be carried more or less continuously by the primary channel , or may be broadcast more infrequently , for example , at the start of a program . as an aid in the scrambling and / or encryption of a program , information relating the programs my be downloaded and locally stored on an authorized basis . as a further measure , a “ channel - hopping ” scheme may be used , wherein different related channels are used at different times , with only authorized viewers being provided with the overall plan . as an alternative to the broadcasting of information relating channels , codes may be published in a format similar to the currently available vcr plus system now in use for vcr programming . that is , in addition to a code which contains start / stop times and a single channel number , the same or a different code may also contain multiple channels designations , certain of which provide the supplementary information . as in the current implementation of vcr plus , such code may be entered in the system &# 39 ; s hand - held remote control for reception by the receiver 30 depicted in fig1 . other means for receiving and storing these codes are also possible , including downloading from a personal computer , and so forth . regardless of the technique used to derive the additional programming information , on - screen programming techniques may be used to enable a user to program in the information so as to label it , for example , to designate a particular channel of the decoder to identify the station call letters or to provide more descriptive information . as shown in fig2 , these features may be implemented with a signal separator 52 , feeding primary and secondary signals to individual tuners 54 a and 54 b interfaced to an optional descrambler 10 . a signal recombiner 56 is preferably used prior to the audio / video switching matrix 24 , providing a combined signal output at 24 . it will be appreciated by those of skill in the art of audio / video mixing and control that other circuit implementations may be used to carry out the broad goal of the invention to integrate multiple inputs to provide a cohesive enjoyment environment . for example , if desired , provisions may be included for an additional internal or external plug - in module ( not shown ), with associated outputs , to provide modified signals for these special purposes . in addition , the system may be adapted to provide multiple outputs enabling a user to record the separate programs associated with all participating channels for subsequent playback . such playback may occur , for example , through the system comprising the invention , through separate inputs and using single recombiner 56 shown in fig2 where advantageous . the operation of the entire unit is controlled by a system controller 32 . this controller may receive input signals from an infrared remote - control receiver 30 , or from any of a variety of user input devices , such as keyboards or computer interfaces ( not shown ). in addition , it is capable of communicating with the public switched telephone network , through an optional telephone interface ( not shown ), enabling the cable converter unit to interface with systems which provide pay - per - view services or other specialized billing and program - ordering schemes . another feature of the invention is the ability to manipulate channel assignments by way of the system controller . for example , the user may choose to assign cable converter channels 1 , 2 , and 3 to broadcast channels 2 , 4 , and 7 ; the user might choose to assign cable converter channel 4 to cable system channel 40 , and cable converter channel 5 to direct - broadcast satellite channel 15 . in this way , the user is able to select any channel line - up desired , including the channels selected from all sources available in any order , and with any channel numerical designation . although not shown , it is to be understood that system controller 32 interfaces to an appropriate memory device for storing these channel assignments , including the user - defined designations . in an alternative embodiment , optional mpeg decoders or other digital signal processors ( not shown ) may be enabled and / or have their operating parameters configured under control of the system controller , using a similar modular approach to that described herein above with reference to descrambler modules .