SU851460A1 - Method of magnetic recording of digital information - Google Patents

Description

(54) METHOD MAGNETIC RECORDING OF DIGITAL INFORMATION

one

The invention relates to instrumentation and can be used when recording and reproducing digital information.

A known method of recording and reproducing digital information by frequency modulation of a carrier with a binary code Hz.

However, the signals of this recording method do not have their own: 1: self-synchronization, which does not allow to achieve high recording density and reliability of information recovery.

The closest to-proposed is a digital in-recording method. formations by manipulating the carrier multilevel code, in which the values of the information signal correspond to the characteristics of the manipulation G23. ,

A disadvantage of the known method of recording digital information is the impossibility of self-synchronization during reproduction in the case of a sequence of identical signal values.

The purpose of the invention is to increase the reliability of reproduction of information.

The goal is achieved by the fact that in the method of magnetic recording of digital information when recording each adjacent two identical values of the information signal, the second of them is manipulated by an additional sign of manipulation.

FIG. 1 shows the conversion of a recorded stake when recording with a multi-positioned keyed signal, FIG. 2 is a block diagram of an apparatus for recording-reproducing; FIG. 3 10 is an example of binary code manipulation; FIG. 4 is a block diagram for recording and reproducing binary information.

In the case of recording information with a multi-level code, such as dibits, the original binary code (Fig. 1) is converted to multi-level.

In this case, each level of the code corresponds to the main main sign of the manipulation. In addition, one additional feature of the sync signal is introduced, the introduction of which allows the frequency beat to be restored during playback of the recorded information.

A device for recording-reproducing (Fig. 2) contains a binary code shift register 1, a binary code converter into a multi-level converter 2, a control circuit 3, a manipulator 4, a recording head 5, magnetic media 6, a symbol comparison circuit 7, a reproducing head 8, a demodulator 9, a memory element 10 and a clock allocation circuit 11. The device works as follows.

Initially, the initial binary code is entered into register 1. The value of the last two bits is converted into a multilevel code of the converter 2, which in turn, through scheme 3, controls the manipulator 4, B, the process of manipulating each character by the scheme 7 compares the last two dibitoes in register 1, and if they are equivalent and registered Since the symbol is manipulated by its sign and not by a sync signal, the memory element in the control circuit 3 is set to one. Upon the arrival of the next clock pulse, information is shifted in the register 1, and the circuit 3 switches to the control of the manipulation of the next symbol. In this case, if the memory element of the circuit 3 is in the single state, then the manipulator 4 generates a sync signal, otherwise, the sign of the manipulation corresponds to the signal at the output of the converter 2.

When the recorded information is restored by the demodulator 9, the recorded information is recognized. The signals of the first four outputs of the demodulator 9 correspond to the four basic manipulation patterns and set the memory element 10 to the appropriate state.

Memory element 10 converts the recovered multilevel code to binary. Reading the binary code from the clock signal from the output of the allocation circuit 11 generates pulses at the moment of a change in the manipulation feature. In this case, in the case of the recovery of the synchronization signal, the state of the block 10 does not change, and the clock frequency pulse is generated, therefore, from the output of the memory element 10, it is reread: the previously restored symbol.

Thus, using the main and one additional sign of manipulation, a one-track recording of information is carried out with the possibility of self-synchronization.

In the particular case, when writing in binary code (Fig. 3), two main and third additional indications of manipulation are used. In this case, the technical implementation of the device (Fig. 4) is greatly simplified. There is no binary-to-multi-level converter 2, the comparison circuit 7 is simplified, and the memory element 10 is designed as an RS flip-flop.

The proposed method can be effectively applied to frequency and phase manipulation methods. The use of one additional feature of manipulation allows one to form with self-synchronization, which, in turn, leads to an increase in the accuracy of information recovery and simplifies the implementation of clock extract frequency blocks.

Claims (2)

1.Patent of France No. 2115551, f CL. G 11 B 5/09, 20.12.79 .. 2. USSR author's certificate number 610162, CL. .G 11 V 5/09, 23.12.76 (prototype). Juitl Tact. f fig. four