SU1001167A1 - Method of recording digital information onto movable member record carrier - Google Patents

Description

The invention relates to instrumentation, in particular to magnetic recording, and may find application in magnetic recording of digital information.

A known method of magnetic recording of digital information by forming a recording current based on the modulation of each period of the carrier along two levels by one of two bits of digital information. A pulse sequence with a period having more than two opposite-polarity pulses is used as the carrier, the first of which is equal to half the duration of the period fj,

However, this method does not allow for a high recording density.

The closest to the proposed technical essence is a method of magnetic recording of digital information, in which, when generating a recording current according to the modulation result of two digital information carriers, one of the two bits is encoded by a half-period of the carrier wave, and the other is half-time of the carrier wave with addition to it or filling parts of it one or more periods of oscillation of a higher frequency 2.

However, this method does not provide high reliability of reproduction of information. Zero bits are decoded by a pair of unipolar pulses, the amplitude of one of which is significantly less than the other.

10 and is comparable with the level of noMqjc. The difference in the signal levels is explained by the short duration of the first demagnetizing signal, which leads to a low magnetisation of the print on the magnetic tape, and the overlap from 15 seals of the same magnetisation. As a result, the accuracy of the reproduction of information is low.

The purpose of the invention is to reduce the 2Q error in recovering digital information.

Claims (2)

The goal is achieved by the fact that in the method of recording digital information on a movable magnetic carrier by generating a recording current of two frequencies: a carrier and a high-frequency filling, one of the two information bits is recorded by a half-period of carrier frequency and the other the high-frequency filling of the rest, the duration of the first filling pulse / is set equal to the period of high-frequency oscillations. FIG. 1a and 1b shows coding zero bits by the known and proposed methods, respectively; in fig. 2 is a functional diagram implementing the proposed SPOD; in fig. 3 - appropriate for the scheme. In the latter method, the duration of the first demagnetizing pulse is equal to the period of high-frequency oscillations. The duration of the information signal is 1/4 (carrier period. The rest of the period is occupied by high-frequency demagnetizing oscillations. As a result, the magnetic imprints produced by the first and high demagnetizing and information pulses do not overlap and have almost identical magnetization levels. The emf is 400 times stronger, shown in FIG. 16, where the signals ,, and Uc2 have equal amplitudes of 1.6 V., the level of interference does not exceed 100 mV. The unit bits are encoded in the same way as the known method. t as follows Fig. 2). From the high-frequency generator 1, which forms demagnetizing oscillations, the pulses arrive at a four-bit binary counter 2. The decoder 3 generates signals that control the operation of counter 2 and the sequence generator for zero bits 4. Depending on the type of information being written (O or 1), the module Torus 5 encodes incoming circulating information in accordance with the proposed method. A high-frequency generator (Fig. Assembled on inverters 6-8; 9 is a binary four-bit counter decoder 3 implemented on AND 1-12 elements; 13 a carrier bit generator on AND 13 element; a modulator 5 is assembled on elegant elements 14-18. High-frequency output. the generator is connected to the input of a four-bit binary counter 9, the first bit of which forms high-frequency demagnetizing oscillations arriving at the input of the carrier of zero bits 13, the second, third and fourth bits are connected to the inputs of the element 10 forming the first wide the demagnetizing pulse of the third and fourth bits are also connected to the inputs of the element 11 forming the information shelf, the outputs of elements 10 and 11 are connected to the inputs of the element 13, the fourth discharge of the counter 9 is connected to the counting input of the trigger on the element 14 and the first input of the element 12, the second input of which receives input information, and the output controls the operation of counter 9 at input R, the direct output of flip-flop 14 is connected to the first upper input of element 1.8 (2I-2 OR-NOT), to the second input of which input information, and with the first In the input of the element 17 (2I-2 OR-NOT), the second input of which is connected to the output of the element 13. The inverse output of the trigger 14 is connected to the first lower input of the element 17, the second input of the output of the element 13 is fed to the second input The output of element 17 is connected to the second lower input of AND of element 18, from the output of which the coded information is removed. The signals from the high-frequency ipaptopa collected on elements 6-8 are fed to the input of a binary counter 9. With the first discharge of the counter, high-frequency demagnetizing oscillations are received at the input of the ZI-NE element 13. Here, the high-frequency oscillations are strobed by either the first wide demagnetizing pulse formed by the element 10, or by an information shelf formed by element 2 AND-NOT 11. Thus formed, the carrier of zero bits is inverted by elements 15 and its direct and inverse values are fed to element 17. Change The carrier phase is implemented by a counting trigger 14 for each next written bit. The zero bits of the recorded information allow the carrier to pass from element 17 through element 18 (2I-2ILI-NO) to the recording amplifier. The single bits permit the passage of the signal from the trigger 14 through the element 18. The element 12 (2I) resets the counter 9 when writing single bits, as soon as a high potential is established on bit 8. Thus, the zero bits of the input digital sequence are encoded by a carrier consisting of a first wide demagnetizing pulse, high-frequency demagnetization oscillations, and an information shelf. The single bits are encoded by the signal taken from the counting trigger 9. These signals are equal in length to half the length of the zero-bit carrier. The proposed method of magnetic recording of digital information is implemented on a prototype of a tape drive mechanism, which is interfaced with the VtoKpo computer Electronics-60 using an interface. The recording was carried out with the following parameters of the digital storage device: the speed of the magnetic tape movement — 4.76 cm / s carrier frequency (output 8p of the counter 9) —4 kHz, demagnetizing oscillation frequency — 32 kHz. In the case of magnetic recording of digital information using the proposed method, 8 bits of digital information are recorded on one side of the MK-60 cassette, which corresponds to a recording density of about 100 bits / MMi. The information is reliably read during repeated reproduction. It is practically impossible to reproduce this amount of information when recording in a known manner. The proposed method of magnetic recording of digital information is implemented in the automated system of technological control Link-M. A digital magnetic tape drive introduces a control program into the dynamic RAM of an electronic computer's electronic computer. The invention is a method of recording digital information on a movable magnetic carrier by forming a recording current of two frequencies: carrier and high-frequency filling, while one of the two information bits is recorded with a half-cycle of carrier frequency oscillations of the other - part of the period of the carrier frequency with high-frequency filling of the rest, differing from so that, in order to reduce the error in recovering digital information, the duration of the first filling pulse is set equal to the period of high-frequency oscillations niy Sources of information taken into account in the examination 1. The author's certificate of the USSR 542231, cl. G 11 B 5/09, 1975. 2. USSR author's certificate 601744, cl. G 11 B 5/02, 1976 (prototype). liHipofnaci On power recording