SU828216A1 - Method of recording binary onto magnetic carrier - Google Patents

Description

one

The invention relates to instrument making, namely to a-aarats of magnetic recording.

There is a known method of recording a binary code on a magnetic carrier, using which code units are recorded on magnetic carrier by current pulses of different polarity with a frequency two times smaller than the symbol frequency of binary code 1.

The disadvantage of this recording method is to reduce the amplitude of the pulse signals reproduced from the magnetic carrier by a factor of two relative to the maximum possible value, due to the fact that the medium is re-magnetized from zero to height, from 0 to ± B, when used.

There is also known a method of writing a binary code, based on the length of the characters of the code by current drops in different directions, using which units are written at the boundary, and zeros are in the middle of symbol intervals 2.

This method allows to obtain a higher recording density of the binary code, however, the reliability of the reproduced signals when using it at high recording densities is reduced due to the interplay of signals in adjacent symbol intervals and the increased risk of reverse operation after a failure in the magnetic recording channel.

By its technical essence, the closest to the invention is a method of writing a binary code, based on the recording of code units by differences or current pulses of different directions and polarity 3. The PSN is characterized by the fact that the next unit on the carrier, which is in a state of negative magnetization, records the difference in current of the positive direction, if in the symbol interval following it, is one, and

a positive current pulse, if zero is located in this interval, the next unit on the carrier, which is in a state of positive magnetization, is recorded by a current differential of negative

if a zero is located in the symbol interval following it, and a negative current pulse if there is a unit in this interval, the units are recorded after a minimum time interval equal to two periods of the symbol binary frequency.

The error of this method is the processing complexity of the reproduced signals and the relatively low reliability. The recording density is limited by the allowable recording density of current pulses, the maximum frequency of which is half the symbol frequency of the code.

The aim of the invention is to simplify signal processing during reproduction and to increase the reliability and density of the recording.

For this, the next code unit is recorded with a current differential, if there is a unit in the next character interval, and a current pulse, if zero is located in the next character interval.

To increase the recording density, the duration of the recorded current pulse is additionally changed if the unit is located in the second symbol interval following the next unit recorded by the current current, and the current duration remains unchanged if zero is located in this interval.

FIG. 1 pr, and the electrical diagram of the device for carrying out the proposed method; “And FIG. Figure 2 shows clips of electrical signals explaining how the device works.

Input 1 for the information signal is connected to the input of a three-bit shift register 2, the sync input of which is connected to input 3 for the main synchronization signal. The output of the first bit of register 2 is connected to the first inputs of the four-input circuits I 4 and 5, the output of the second bit of this register is connected to the second inputs of the circuits I 4 and 5 and to the first input of the circuit. And 6, and the third-bit output to the third inputs of the And 4 and 5 circuits and to the second input of the And 6 circuit. The input 7 for the auxiliary clock pulse is connected to the fourth inputs of the And 4 and 5 circuits and to the third input of the And 6 circuit, the outputs of which are connected both directly and through blocks 8 and 9 of the delay of the inputs of the OR 10 circuit, as well as to the input of the OR 11 circuit, the output connected to the third stage bit of the second register 2. The output of the circuit 10 is connected to the counting input of the trigger 12, which forms the output signal of the device. The zeroing input of the first bit of register 2 is connected to the output of circuit 4, and the nulling INPUT of the second bit of it is connected to the output of circuit 5.

Input 1 receives binary code signals generated by the BVN method (see diagrams a in Fig. 2) and recorded in the first digit of register 2. These signals are shifted by the main clock signal (diagrams (Fig 2) input to input 3. The inputs of the circuit 6, non-inverted signals from the outputs of the third and second bits of register 2 and the auxiliary clock signal from input 7 (plot e of Fig. 2) are shifted relative to the fundamental frequency by a half period. From the output of circuit 6, the signal (supplied to the second and third bit connectors) Dov register 2, wrapped these times dy

(plots in, g of fig. 2). In this case, the signal to the third-level zero input is fed through circuit 11. The inputs to circuit 4 receive inverted signals from the outputs of the first and second bits and a non-inverted signal from the third bit of register 2, as well as an auxiliary clock signal from input 7. The signal c the output of this circuit also enters via circuit 11 to the zero input of the third bit of register 2 (plot g of fig. 2). Uninverted signals from the outputs of the first and third bits of register 2 and an inverted signal from the output of the second bit of this register, as well as auxiliary signals from input 7, are fed to the inputs of circuit 5. and through scheme I 11 to the third-level zero input (diagrams b, d, fig. 2).

The circuit 10 provides signals from the circuit outputs directly and through blocks 8 and 9. At the output of circuit 10, a signal is formed (plots of Fig. 2), which is then fed to the counting input of trigger 12. At the output of this trigger, signals are generated corresponding to the proposed method.

When implementing the known method, the playback device must distinguish between reproducible signals according to the polarity of responses to current drops, since the direction of the current drops carries information about what is recorded on the carrier. For example, a combination of 11 or 10 (11 positive current differential, 10 negative). In addition, the playback device must distinguish between 1 polarity of current pulses, since in the polarity of the current pulses there is information about which combination of 10 or 11 is recorded on the carrier (11-negative current pulse, and 10 - positive).

This device must also distinguish signals from recorded pulses and current drops.

When implementing the proposed invention, the playback device must distinguish the response to current difference from the response to the current pulse without regard to their polarity. As a result, the procedure for processing reproducible signals is simplified and their reliability is increased.

Claims (1)

1. A method of storing a binary code on a magnetic carrier, based on recording units of a code by ramps and current pulses of different directions and polarities, characterized in that, in order to increase reliability and simplify processing; signal cues, when they are reproduced, the next unit of code is recorded by the current differential, if next