SU1107160A1 - Method of magnetic recording of binary code signals - Google Patents

Abstract

A METHOD FOR RECORDING BINARY CODE SIGNALS MAGNITPY, in which one write current differential is formed at the beginning of a time interval equal to two symbol intervals, in the case of two code points, and a recording current pulse is formed, in the case of a one, zero character group, and the following zero codes form a write current equal in magnitude to the write current of the previous symbol interval on a time interval equal to the symbol interval, characterized in that, in order to increase the recording density, in the case of zero following a group of characters "one, zero" forms a write current pulse at the beginning of a time interval equal to three symbol intervals, and if one follows the group of characters "one zero, also form a recording current pulse on a time interval equal to three character intervals, and delay it relative to the beginning of this interval by half the character interval. (L 05

Description

The invention relates to instrument engineering and can be used in apparatus for magnetic recording of digital information. A known method of magnetic recording of a binary code is based on the recording of code signals by current drops in different directions, in which the signals of units are recorded at the boundary, and the zeros are in the middle of symbol intervals 1. However, the reliability of the reproduced signals when using this method at high recording densities decreases from - for the interplay of signals in adjacent symbol intervals. The closest to the invention to the technical nature is a method of magnetic recording of binary code signals, in which one write current differential is formed at the beginning of a time interval equal to two symbol intervals, in the case of two code units, and a current pulse is formed, in case of a group of characters "One, zero, and in the case of following a code zero, a recording current equal in magnitude to the recording current of the previous symbol interval in a time interval equal to the symbol interval. In this recording method, a signal of a regular code unit is recorded at the current boundary (middle) if there is one in the next character interval, and a current pulse if there is zero 2 in the next character interval. However, the recording density is not inherent in the known method. . The aim of the invention is to increase the recording density. The goal is achieved by the method of magnetic recording of binary code signals, in which one write current differential is formed at the beginning of a time interval equal to two symbol intervals, in case of two code units following, and a recording current pulse is formed, in case of following characters unit, zero, and in the case of following a code zero, a recording current equal in magnitude to the recording current of the previous symbol interval in a time interval equal to the symbol interval, in the case of zero following the group with The characters "unit, zero, form a write current pulse at the beginning of a time interval equal to three character intervals, and in the case of a unit following the character group" one, zero, also form a recording current pulse in a time interval equal to three character intervals, and delay it relative to the beginning of this interval to half the character interval. FIG. 1 shows one of the possible variants of the electrical block diagram of a device that implements the proposed method of writing a binary code; in fig. 2 - diagrams of electrical signals explaining the operation of the device. The device contains input 1 for signals of code units connected to the input of shift register 2 of three bits, the sync input of which is connected to input 3 for code sync signals, and selector 4 of the one, group of characters one, zero , the unit and the selector 6 of the group “unit, zero, zero, while the output of the selector 5 is connected through a delay unit 7 to the first input of the OR circuit 8, and the output of the selector 6 - directly to the second input of the OR circuit 8, the output connected to the generator 9 of a pulse pair signals that moved relative to each other by a time interval equal to the duration of the recording current pulse, the output of which is connected to the first input of the OR circuit 10, the second input of which is connected to the output of the selector 4 through the adjustable delay unit 11, which, moreover, also like the outputs of the selectors 5 and 6 is connected to the OR 12 three-input circuit, the output is connected to the zeroing input of register 2, and the output of the OR 10 circuit is connected to the counting input of the trigger 13, which through the amplifier 14 is connected to the recording head 15. The signals of the code units (Fig. 2a) from input 1 are fed to the input of register 2 and are advanced from the discharge to the register's discharge by clock pulses (plots b) fed to input 3. At the same time, the output signal (plots c) appears at the output of the selector 5 if code 101 is recorded in register 2, which is delayed by block 7 by half of the character interval (plot d) and fed to the input of the OR circuit 8, the second input of which receives without delay signals from the output of selector 6 of code group 100 (plot d), combining these signals with the OR circuit 8, they trigger generator 9, the output the signals of which are shown in plots e. The signals of generator 9 are combined in the OR 10 circuit with the output signals of selector 4 of the code group U (plots g), which are preliminarily delayed in the AND block (plots 3). The output signals of the OR 10 circuit (plots and) are fed to the counting input of the trigger 13, at the output of which signals (plots k) are formed, arriving after amplification in the amplifier 14 into the head 15 for recording on magnetic media. The signals from the output of the selectors 4-6 are fed to the input of the OR circuit 12 and, after being combined in this circuit, the register 2 is zeroed (the plots of Fig. 2 are not shown). Due to this, it is possible to exclude the possibility that the same code symbols fall into adjacent groups.

In the process of restoring the source code during playback, the groups "one, zero, zero and" one, zero, one are distinguished according to the time shift of the reproduced pulses relative to the beginning of the symbol interval.

The adjustable delay in block 11 allows the mutual temporal arrangement of pulses and recording current drops to change, which improves the processing conditions of the reproduced signals.

The beneficial effect is an increase in the density of the binary code signal recording onto magnetic media is achieved by the fact that

in comparison with the known method, the value of the minimum period of a pulse following for recording onto a carrier from two periods of code symbols is increased to 2.5 symbol intervals. In addition, the conditions for decoding the differential-pulse combination following the minimum interval are significantly improved by increasing this interval due to the shift of the pulses relative to the sequence of differences.

Thus, the use of the proposed method of recording a binary code on a magnetic medium as compared with the known one allows an increase in the recording density by 20-25%.

Code 1 T 1 O 1 1 O O

but

And p p p p p p p o and |

§

and nJL

well

Juul

one

V

about p and

one

one

ML

Jlj.

Jljb

Zt

2.57Fig. 1 O 1 1 1 O p p p /

Claims (1)

METHOD FOR MAGNETIC RECORDING OF BINARY CODE SIGNALS, in which one write current drop is formed at the beginning of a time interval equal to two symbol intervals, in case two code units are followed, and a write current pulse is generated if the group of characters is “one, zero”, and in in the case of following a code zero, a recording current is generated equal to the recording current of the previous symbol interval in a time interval equal to a symbol interval, characterized in that, in order to increase the recording density, in the case of following zero for g upppa of the symbols “unit, zero”, form a pulse of the recording current at the beginning of the time interval equal to three symbol intervals, and in the case of a unit following the group of symbols “unit, zero”, they also form a pulse of the recording current in the time interval equal to three symbol intervals, and delay it relative to the beginning of this interval by half a character interval. jg FIG. 1