Magnetic recording

Abstract

Abstract A MULTICHANNEL RECORDING SYSTEM IS DESCRIBED FOR RECORDING BOTH DIGITAL AND ANALOG INFORMATION. THE RECORDING SYSTEM INCLUDES APPARATUS FOR CONVERTING ANALOG INFORMATION INTO DIGITAL INFORMATION HAVING A PREDETERMINED FORMAT. EACH TRACK OF THE RECORDING APPARATUS RECEIVES A SERIES OF ENCODED FORMAT WORDS CONTAINING A PLURALITY OF TERNARY NRZ PULSES, EACH REPRESENTED BY ANY ONE OF THREE VOLTAGE LEVELS, POSITIVE, NEGATIVE OR ZERO VOLTS DURING A BIT INTERVAL, SUCH THAT THE AVERAGE LEVEL OF EACH WORD IS 0 VOLTS. THE SPECTRUM OF A SIGNAL COMPOSED OF A SERIAL SEQUENCE OF THESE FORMAT WORDS IS CAPABLE OF BEING RECORDED ON A MAGNETIC TAPE RECORDING TRACK WITH A MUCH HIGHER PULSE PACKING DENSITY THAN HERETOFORE POSSIBLE WITH CONVENTIONAL NRZ OR OTHER BINARY RECORDING TECHNIQUES. THE PLAYBACK APPARATUS WHICH FORMS PART OF THE RECORDING SYSTEM INCLUDES CIRCUITRY RESPONSIVE TO THE ZERO AVERAGE PROPERTY OF THE RECORDED WORDS, AND CONTROLS THE TIMING OF THE READOUT OF THE RECORDED INFORMATION SO AS TO PROVIDE PRECISE TIME COHERENCE BETWEEN ALL OF THE RECORDED CHANNELS. THE LATTER CIRCUITRY ALSO CONTROLS THE SYSTEM FOR DESKEWING THE SIGNALS RECORDED SIMULTANEOUSLY ON PARALLEL TRACKS ON THE TAPE DURING PLAYBACK, THEREBY FURTHER ENHANCING THE CAPABILITY OF THIS SYSTEM TO RECORD INFORMATION WITH EXTREMELY HIGH PULSE PACKING DENSITY. BOTH RECORDING AND PLAYBACK IS CONTROLLED BY A COMMON ACCURATE CLOCK SO AS TO FURTHER INSURE COHERENCE BETWEEN SIGNALS RECORDED ON ALL CHANNELS. ALSO INCLUDED IN THE RECORDING SYSTEM IS AN INPUT-OUTPUT SECTION WHICH TRANSLATES INPUT ANALOG INFORMATION INTO DIGITAL FORM FOR RECORDING IN THE VARIOUS CHANNEL AT RATES AND WITH THE FORMAT COMPATIBLE FOR RECORDING WITH THE SYSTEM. THE INPUT-OUTPUT SECTION ALSO REARRANGES THE DIGITAL INFORMATION READ FROM THE MAGNETIC RECORD INTO ITS ORIGINAL ANALOG OR DIGITAL FORM, AS THE CASE MAY BE.

Inventors

• 👤 William R Frazier Jr

Bibliographic Details