Broadcast digital sound processing system

A method of recording and playing analog program signals using signal processor means;

• analog to digital converter means, digital to analog converter means, and computer means interfaced respectively to said signal processor means;
• and a read/write computer data disk interfaced to said computer means;
• said method comprising the steps of:
• (a) storing on said disk first digital program data and second digital program data representing respectively a first analog program signal and a second analog program signal;
• (b) outputting from said signal processor means a mixed analog signal including said first analog program signal and, simultaneously, at least a portion of said second analog program signal by the steps of:
• (1) retrieving said first program data from said disk and transferring said first program data from said computer means to said signal processor means through first playback FIFO (first-in/first-out) buffer means interfacing said computer means with said signal processor means;
• (2) retrieving said second program data from said disk and transferring said second program data from said computer means to said signal processor means through second playback FIFO buffer means interfacing said computer means with said signal processor means;
• and
• (3) constructing said mixed analog signal by said signal processor means digitally mixing at least a portion of said second program data with said first program data and controlling digital to analog conversion of the mixed digital data by said digital to analog converter means;
• (c) recording a third analog program signal by the steps of:
• (1) digitizing by said analog to digital converter said third analog program signal to derive third digital program data;
• (2) transferring said third program data from said signal processor means to said computer means through FIFO record buffer means interfacing said signal processor means to said computer means;
• and
• (3) storing said third program data on said disk;
• and
• (d) performing said outputting step substantially simultaneously with said recording step.

A method of recording analog program signals on a mass storage device of a host computer and playing back same, said method comprising the steps of:

• (a) digitally recording an analog program signal by the steps of:
• (1) receiving an analog program signal and digitizing same to provide a stream of digital program data representing said analog program signal;
• (2) clocking data groups of said stream into a record FIFO (first-in/first-out) buffer;
• (3) periodically causing said host computer to transfer a data block of said data groups from said record buffer to said mass storage device independent of the clocking of succeeding data groups of said stream into said record buffer;
• and
• (4) continuing said clocking and transfer steps until a program file comprising an entirety of said stream has been stored in said mass storage device;
• (b) playing a mixed analog program signal by the steps of:
• (1) causing said host computer to transfer a sequence of first data blocks representing a digitally recorded first analog program signal from said mass storage device to a first playback FIFO buffer;
• (2) causing said host computer to transfer a sequence of second data blocks representing a digitally recorded second analog program signal from said mass storage device to a second playback FIFO buffer;
• (3) digitally mixing said first and second data blocks respectively from said first and second playback buffers to form digitally mixed data groups;
• (4) communicating said digitally mixed data groups to a digital to analog converter (DAC) to thereby reconstruct a mixed analog program signal including said first analog program signal and at least a portion of said second analog program signal;
• and
• (5) outputting said mixed analog program signal;
• and
• (c) performing said recording and playing steps substantially simultaneously.

An apparatus for recording and playing back analog program signals, said apparatus comprising:

• (a) a host computer;
• (b) a read/write data storage disk interfaced to said computer, said disk for storage of digital program data representing program signals;
• (c) digitizer means receiving an analog program signal and operative to convert said analog program signal to digital program data representing said analog program signal for storage on said disk;
• (d) signal reconstruction means interfaced to said computer and operative to reconstruct an analog program signal from digital program data communicated thereto;
• (e) signal processor means interfaced to said digitizer means, said reconstruction means, and said computer means;
• said signal processor means controlling operation of said digitizer means and said reconstruction means and controlling communication of said program data from said digitizer means to said computer and from said computer to said reconstruction means;
• (f) record FIFO (first-in/first-out) buffer means interfacing said signal processor means and said computer and enabling independent access to said record buffer means by said signal processor means and said computer to expedite transfer to said program data from said digitizer means to said computer;
• (g) first playback FIFO buffer means and second playback FIFO buffer means interfacing said computer and said signal processor means and enabling independent access to said playback buffer means by said computer and said signal processor means to expedite transfer of first and second independent sets of program data from said computer to said reconstruction means;
• and
• (g) analog signal output means coupled to said reconstruction means and operative to output a reconstructed analog program signal represented by program data communicated to said reconstruction means.